Keratinocytes
Epidermis
Skin
Cells, Cultured
Keratins
Psoriasis
Ultraviolet Rays
Keratin-10
Keratin-14
Cell Differentiation
Skin, Artificial
Hair Follicle
Melanocytes
RNA, Messenger
Skin Physiological Phenomena
Oncogene Proteins, Viral
Cell Line, Transformed
Cell Division
Papillomavirus E7 Proteins
Papillomaviridae
Mouth Mucosa
Fibroblasts
Skin Diseases
Dermis
Desmosomes
Gene Expression
Gene Expression Regulation
Transglutaminases
Papilloma
Signal Transduction
Pemphigus
Apoptosis
Cell Movement
Fibroblast Growth Factor 7
Desmoglein 3
Hemidesmosomes
Protein Precursors
Hair
Up-Regulation
Dermatitis, Atopic
Intermediate Filament Proteins
Keratolytic Agents
Keratin-1
Sebaceous Glands
Immunohistochemistry
Non-Fibrillar Collagens
Skin Transplantation
Integrin beta4
Carcinoma, Squamous Cell
Acantholysis
Mice, Transgenic
Tetradecanoylphorbol Acetate
Promoter Regions, Genetic
Transfection
Calcium
Langerhans Cells
Cell Transformation, Neoplastic
Epidermolysis Bullosa Simplex
Human papillomavirus 16
Epithelium
Caspase 14
Coculture Techniques
Reverse Transcriptase Polymerase Chain Reaction
9,10-Dimethyl-1,2-benzanthracene
Epidermal Growth Factor
Blotting, Western
Pemphigus, Benign Familial
Desmoplakins
Cell Survival
DNA-Binding Proteins
Transcription Factors
Keratin-15
Keratin-17
Epidermolysis Bullosa, Junctional
Keratin-5
Base Sequence
Transcription, Genetic
Molecular Sequence Data
Down-Regulation
Phosphorylation
Integrin alpha6
Ichthyosis, Lamellar
Repressor Proteins
Desmogleins
Skin Aging
Interleukin-8
Epithelial Cells
Tumor Suppressor Protein p53
Dermatitis, Allergic Contact
Mice, Knockout
Enzyme Activation
Fluorescent Antibody Technique
Mice, Inbred BALB C
Differential regulation of the human nidogen gene promoter region by a novel cell-type-specific silencer element. (1/6758)
Transfection analyses of the human nidogen promoter region in nidogen-producing fibroblasts from adult skin revealed multiple positive and negative cis-acting elements controlling nidogen gene expression. Characterization of the positive regulatory domains by gel mobility-shift assays and co-transfection studies in Drosophila SL2 cells unequivocally demonstrated that Sp1-like transcription factors are essential for a high expression of the human nidogen gene. Analysis of the negative regulatory domains identified a novel silencer element between nt -1333 and -1322, which is bound by a distinct nuclear factor, by using extracts from adult but not from embryonal fibroblasts. In embryonal fibroblasts, which express significantly higher amounts of nidogen mRNA as compared with adult fibroblasts, this inhibitory nidogen promoter region did not affect nidogen and SV40 promoter activities. The silencer element seems to be active only in nidogen-producing cells. Therefore this regulatory element might function in vivo to limit nidogen gene expression in response to external stimuli. However, none of the identified regulatory elements, including the silencer, contribute significantly to cell-specific expression of the human nidogen gene. Instead we provide evidence that gene expression in epidermal keratinocytes that are not producing nidogen is repressed by methylation-specific and chromatin-dependent mechanisms. (+info)The integrin alpha v beta 6 binds and activates latent TGF beta 1: a mechanism for regulating pulmonary inflammation and fibrosis. (2/6758)
Transforming growth factor beta (TGF beta) family members are secreted in inactive complexes with a latency-associated peptide (LAP), a protein derived from the N-terminal region of the TGF beta gene product. Extracellular activation of these complexes is a critical but incompletely understood step in regulation of TGF beta function in vivo. We show that TGF beta 1 LAP is a ligand for the integrin alpha v beta 6 and that alpha v beta 6-expressing cells induce spatially restricted activation of TGF beta 1. This finding explains why mice lacking this integrin develop exaggerated inflammation and, as we show, are protected from pulmonary fibrosis. These data identify a novel mechanism for locally regulating TGF beta 1 function in vivo by regulating expression of the alpha v beta 6 integrin. (+info)Murine matrix metalloproteinase 9 gene. 5'-upstream region contains cis-acting elements for expression in osteoclasts and migrating keratinocytes in transgenic mice. (3/6758)
Knowledge about the regulation of cell lineage-specific expression of extracellular matrix metalloproteinases is limited. In the present work, the murine matrix metalloproteinase 9 (MMP-9) gene was shown to contain 13 exons, and the 2.8-kilobase pair upstream region was found to contain several common promoter elements including a TATA box-like motif, three GC boxes, four AP-1-like binding sites, an AP-2 site, and three PEA3 consensus sequences that may be important for basic activity of the gene. In order to identify cell-specific regulatory elements, constructs containing varying lengths of the upstream region in front of a LacZ reporter gene were made and studied for expression in transgenic mice generated by microinjection into fertilized oocytes. Analyses of the mice revealed that the presence of sequences between -2722 and -7745 allowed for expression in osteoclasts and migrating keratinocytes, i. e. cells that have been shown to normally express the enzyme in vivo. The results represent the first in vivo demonstration of the location of cell-specific control elements in a matrix metalloproteinase gene and show that element(s) regulating most cell-specific activities of 92-kDa type collagenase are located in the -2722 to -7745 base pair region. (+info)The L1 major capsid protein of human papillomavirus type 11 recombinant virus-like particles interacts with heparin and cell-surface glycosaminoglycans on human keratinocytes. (4/6758)
The L1 major capsid protein of human papillomavirus (HPV) type 11, a 55-kDa polypeptide, forms particulate structures resembling native virus with an average particle diameter of 50-60 nm when expressed in the yeast Saccharomyces cerevisiae. We show in this report that these virus-like particles (VLPs) interact with heparin and with cell-surface glycosaminoglycans (GAGs) resembling heparin on keratinocytes and Chinese hamster ovary cells. The binding of VLPs to heparin is shown to exhibit an affinity comparable to that of other identified heparin-binding proteins. Immobilized heparin chromatography and surface plasmon resonance were used to show that this interaction can be specifically inhibited by free heparin and dextran sulfate and that the effectiveness of the inhibitor is related to its molecular weight and charge density. Sequence comparison of nine human L1 types revealed a conserved region of the carboxyl terminus containing clustered basic amino acids that bear resemblance to proposed heparin-binding motifs in unrelated proteins. Specific enzymatic cleavage of this region eliminated binding to both immobilized heparin and human keratinocyte (HaCaT) cells. Removal of heparan sulfate GAGs on keratinocytes by treatment with heparinase or heparitinase resulted in an 80-90% reduction of VLP binding, whereas treatment of cells with laminin, a substrate for alpha6 integrin receptors, provided minimal inhibition. Cells treated with chlorate or substituted beta-D-xylosides, resulting in undersulfation or secretion of GAG chains, also showed a reduced affinity for VLPs. Similarly, binding of VLPs to a Chinese hamster ovary cell mutant deficient in GAG synthesis was shown to be only 10% that observed for wild type cells. This report establishes for the first time that the carboxyl-terminal portion of HPV L1 interacts with heparin, and that this region appears to be crucial for interaction with the cell surface. (+info)C5a receptor and interleukin-6 are expressed in tissue macrophages and stimulated keratinocytes but not in pulmonary and intestinal epithelial cells. (5/6758)
The anaphylatoxin derived from the fifth component of the human complement system (C5a) mediates its effects by binding to a single high-affinity receptor (C5aR/CD88), the expression of which has been traditionally thought to be restricted to granulocytes, monocytes, macrophages (Mphi), and cell lines of myeloid origin. Recent immunohistochemical data suggested that human bronchial and alveolar cells express C5aR as well. To reexamine the tissue distribution of human C5aR expression, transcription of the C5aR gene was investigated in normal and pathologically affected human lung (bronchopneumonia, tuberculosis), large intestine (acute appendicitis, Crohn's disease), and skin (pyogenic granuloma, lichen planus) using in situ hybridization. In contrast to previous evidence, C5aR mRNA could not be detected in pulmonary or intestinal epithelial cells, whereas keratinocytes in inflamed but not in normal skin revealed detectable levels of C5aR transcripts. Additionally, it could be documented that only migrating Mphi express C5aR mRNA, whereas sessile Mphi in normal tissues and epithelioid/multinucleated Mphi found in granulomatous lesions do not. Because C5a has been demonstrated to upregulate the expression of interleukin (IL)-6 in human monocytes, we also studied IL-6 gene transcription in parallel to the C5aR. IL-6 mRNA was detectable in many tissue Mphi. Surprisingly, a tight co-expression of C5aR and IL-6 mRNA was observed in keratinocytes from lesions of pyogenic granuloma and lichen planus. These results point to an as yet unknown role for C5a in the pathogenesis of skin disorders beyond its well-defined function as a chemoattractant and activator of leukocytes. (+info)CCAAT/enhancer-binding proteins. A role in regulation of human involucrin promoter response to phorbol ester. (6/6758)
The phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) is a potent inducer of keratinocyte differentiation and of involucrin gene expression. In the present study we show that a CCAAT/enhancer-binding protein (C/EBP) site in the proximal regulatory region is required for the phorbol ester response. Mutation of the C/EBP site results in the loss of basal and TPA-responsive activity. Gel mobility supershift analysis shows that C/EBPalpha binding to this site is increased by TPA treatment. Moreover, cotransfection of the human involucrin reporter plasmid with C/EBPalpha increases promoter activity to an extent comparable with TPA treatment. Mutation of the C/EBP-binding site eliminates these responses. Transfection experiments using GADD153 to create C/EBP-null conditions confirm that C/EBP factors are absolutely required for promoter activity and TPA responsiveness. C/EBPbeta and C/EBPdelta inhibit both TPA- and C/EBPalpha-dependent promoter activation, indicating functional differences among C/EBP family members. These results suggest that C/EBP transcription factor activity is necessary for basal promoter activity and TPA response of the involucrin gene. (+info)UV-A-induced decrease in nuclear factor-kappaB activity in human keratinocytes. (7/6758)
Previous reports have demonstrated an increase in nuclear factor-kappaB (NF-kappaB) activity in response to UV radiation. These studies have essentially focused on the DNA-damaging fraction of solar UV radiation (UV-B and UV-C). In contrast, the effects of UV-A radiation (320-400 nm) on NF-kappaB are not well known. In this study, we present evidence that UV-A radiation induces a marked decrease in NF-kappaB DNA-binding activity in NCTC 2544 human keratinocytes. In addition, NCTC 2544 keratinocytes pretreated with UV-A fail to respond to NF-kappaB inducers. Moreover, UV-A radiation induces a decrease in NF-kappaB-driven luciferase reporter gene expression in NCTC 2544 keratinocytes. The expression of the gene encoding IkappaBalpha (IkappaB is the NF-kappaB inhibitor), which is closely associated with NF-kappaB activity, is also reduced (3-fold) upon UV-A treatment. Our results indicate that the UV-A-induced decrease in NF-kappaB DNA-binding activity is associated with a decrease in the levels of the p50 and p65 protein subunits. This is the first evidence that an oxidative stress, such as UV-A radiation, may induce a specific decrease in NF-kappaB activity in mammalian cells, probably through degradation of NF-kappaB protein subunits. These findings suggest that UV-A could modulate the NF-kappaB-dependent gene expression. (+info)Psoriatic keratinocytes show reduced IRF-1 and STAT-1alpha activation in response to gamma-IFN. (8/6758)
Psoriasis is a chronic inflammatory dermatosis characterized by hyperproliferative keratinocytes (KC). The skin lesions are infiltrated by T cells, which secrete gamma interferon (gamma-IFN) and are believed to be necessary to maintain the psoriatic phenotype. In normal KC, gamma-IFN is a potent inhibitor of proliferation, but proliferation of KC persists in psoriatic plaques despite the presence of gamma-IFN. Immunostaining of interferon regulatory factor-1 (IRF-1) revealed that IRF-1 was localized to the basal cells of the epidermis in normal and in nonlesional psoriatic skin, but was suprabasal or completely absent in lesional psoriatic skin. This finding led to the hypothesis that abnormal signaling in the gamma-IFN pathway may occur in psoriatic KC. To test this hypothesis, we measured activation of IRF-1 and signal transducer and activator of transcription (STAT)-1alpha transcription factors in KC after stimulation with gamma-IFN. Primary cultures of KC from normal and nonlesional psoriatic skin were stimulated with gamma-IFN and subsequent transcription factor activation was measured by electrophoretic mobility shift assay. Psoriatic KC showed a reduced induction of IRF-1 and STAT-1alpha activation after stimulation with gamma-IFN, compared with normal KC. Reduced activation of IRF-1 and STAT-1alpha in response to gamma-IFN indicates a fundamental defect in the growth and differentiation control of psoriatic KC in the absence of the influence of other cell types. (+info)Keratinocytes are the predominant type of cells found in the epidermis, which is the outermost layer of the skin. These cells are responsible for producing keratin, a tough protein that provides structural support and protection to the skin. Keratinocytes undergo constant turnover, with new cells produced in the basal layer of the epidermis and older cells moving upward and eventually becoming flattened and filled with keratin as they reach the surface of the skin, where they are then shed. They also play a role in the immune response and can release cytokines and other signaling molecules to help protect the body from infection and injury.
The epidermis is the outermost layer of the skin, composed mainly of stratified squamous epithelium. It forms a protective barrier that prevents water loss and inhibits the entry of microorganisms. The epidermis contains no blood vessels, and its cells are nourished by diffusion from the underlying dermis. The bottom-most layer of the epidermis, called the stratum basale, is responsible for generating new skin cells that eventually move up to replace dead cells on the surface. This process of cell turnover takes about 28 days in adults.
The most superficial part of the epidermis consists of dead cells called squames, which are constantly shed and replaced. The exact rate at which this happens varies depending on location; for example, it's faster on the palms and soles than elsewhere. Melanocytes, the pigment-producing cells, are also located in the epidermis, specifically within the stratum basale layer.
In summary, the epidermis is a vital part of our integumentary system, providing not only physical protection but also playing a crucial role in immunity and sensory perception through touch receptors called Pacinian corpuscles.
In medical terms, the skin is the largest organ of the human body. It consists of two main layers: the epidermis (outer layer) and dermis (inner layer), as well as accessory structures like hair follicles, sweat glands, and oil glands. The skin plays a crucial role in protecting us from external factors such as bacteria, viruses, and environmental hazards, while also regulating body temperature and enabling the sense of touch.
"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.
Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.
It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.
Keratins are a type of fibrous structural proteins that constitute the main component of the integumentary system, which includes the hair, nails, and skin of vertebrates. They are also found in other tissues such as horns, hooves, feathers, and reptilian scales. Keratins are insoluble proteins that provide strength, rigidity, and protection to these structures.
Keratins are classified into two types: soft keratins (Type I) and hard keratins (Type II). Soft keratins are found in the skin and simple epithelial tissues, while hard keratins are present in structures like hair, nails, horns, and hooves.
Keratin proteins have a complex structure consisting of several domains, including an alpha-helical domain, beta-pleated sheet domain, and a non-repetitive domain. These domains provide keratin with its unique properties, such as resistance to heat, chemicals, and mechanical stress.
In summary, keratins are fibrous structural proteins that play a crucial role in providing strength, rigidity, and protection to various tissues in the body.
Psoriasis is a chronic skin disorder that is characterized by recurrent episodes of red, scaly patches on the skin. The scales are typically silvery-white and often occur on the elbows, knees, scalp, and lower back, but they can appear anywhere on the body. The exact cause of psoriasis is unknown, but it is believed to be related to an immune system issue that causes skin cells to grow too quickly.
There are several types of psoriasis, including plaque psoriasis (the most common form), guttate psoriasis, inverse psoriasis, pustular psoriasis, and erythrodermic psoriasis. The symptoms and severity of the condition can vary widely from person to person, ranging from mild to severe.
While there is no cure for psoriasis, various treatments are available that can help manage the symptoms and improve quality of life. These may include topical medications, light therapy, and systemic medications such as biologics. Lifestyle measures such as stress reduction, quitting smoking, and avoiding triggers (such as certain foods or alcohol) may also be helpful in managing psoriasis.
According to the medical definition, ultraviolet (UV) rays are invisible radiations that fall in the range of the electromagnetic spectrum between 100-400 nanometers. UV rays are further divided into three categories: UVA (320-400 nm), UVB (280-320 nm), and UVC (100-280 nm).
UV rays have various sources, including the sun and artificial sources like tanning beds. Prolonged exposure to UV rays can cause damage to the skin, leading to premature aging, eye damage, and an increased risk of skin cancer. UVA rays penetrate deeper into the skin and are associated with skin aging, while UVB rays primarily affect the outer layer of the skin and are linked to sunburns and skin cancer. UVC rays are the most harmful but fortunately, they are absorbed by the Earth's atmosphere and do not reach the surface.
Healthcare professionals recommend limiting exposure to UV rays, wearing protective clothing, using broad-spectrum sunscreen with an SPF of at least 30, and avoiding tanning beds to reduce the risk of UV-related health problems.
Keratin-10 is a type II keratin protein that is primarily expressed in the differentiated layers of stratified squamous epithelia, including the skin's epidermis. It plays a crucial role in providing structural support and protection to these epithelial tissues. Keratin-10 pairs with keratin-1 to form intermediate filaments, which are essential for maintaining the integrity and stability of epithelial cells. The expression of keratin-10 is often used as a marker for terminal differentiation in epidermal keratinocytes.
Keratin-14 is a type of keratin protein that is specifically expressed in the suprabasal layers of stratified epithelia, including the epidermis. It is a component of the intermediate filament cytoskeleton and plays an important role in maintaining the structural integrity and stability of epithelial cells. Mutations in the gene encoding keratin-14 have been associated with several genetic skin disorders, such as epidermolysis bullosa simplex and white sponge nevus.
Wound healing is a complex and dynamic process that occurs after tissue injury, aiming to restore the integrity and functionality of the damaged tissue. It involves a series of overlapping phases: hemostasis, inflammation, proliferation, and remodeling.
1. Hemostasis: This initial phase begins immediately after injury and involves the activation of the coagulation cascade to form a clot, which stabilizes the wound and prevents excessive blood loss.
2. Inflammation: Activated inflammatory cells, such as neutrophils and monocytes/macrophages, infiltrate the wound site to eliminate pathogens, remove debris, and release growth factors that promote healing. This phase typically lasts for 2-5 days post-injury.
3. Proliferation: In this phase, various cell types, including fibroblasts, endothelial cells, and keratinocytes, proliferate and migrate to the wound site to synthesize extracellular matrix (ECM) components, form new blood vessels (angiogenesis), and re-epithelialize the wounded area. This phase can last up to several weeks depending on the size and severity of the wound.
4. Remodeling: The final phase of wound healing involves the maturation and realignment of collagen fibers, leading to the restoration of tensile strength in the healed tissue. This process can continue for months to years after injury, although the tissue may never fully regain its original structure and function.
It is important to note that wound healing can be compromised by several factors, including age, nutrition, comorbidities (e.g., diabetes, vascular disease), and infection, which can result in delayed healing or non-healing chronic wounds.
Cell differentiation is the process by which a less specialized cell, or stem cell, becomes a more specialized cell type with specific functions and structures. This process involves changes in gene expression, which are regulated by various intracellular signaling pathways and transcription factors. Differentiation results in the development of distinct cell types that make up tissues and organs in multicellular organisms. It is a crucial aspect of embryonic development, tissue repair, and maintenance of homeostasis in the body.
Dermatitis is a general term that describes inflammation of the skin. It is often characterized by redness, swelling, itching, and tenderness. There are many different types of dermatitis, including atopic dermatitis (eczema), contact dermatitis, seborrheic dermatitis, and nummular dermatitis.
Atopic dermatitis is a chronic skin condition that often affects people with a family history of allergies, such as asthma or hay fever. It typically causes dry, scaly patches on the skin that can be extremely itchy.
Contact dermatitis occurs when the skin comes into contact with an irritant or allergen, such as poison ivy or certain chemicals. This type of dermatitis can cause redness, swelling, and blistering.
Seborrheic dermatitis is a common condition that causes a red, itchy rash, often on the scalp, face, or other areas of the body where oil glands are located. It is thought to be related to an overproduction of oil by the skin's sebaceous glands.
Nummular dermatitis is a type of eczema that causes round, coin-shaped patches of dry, scaly skin. It is more common in older adults and often occurs during the winter months.
Treatment for dermatitis depends on the underlying cause and severity of the condition. In some cases, over-the-counter creams or lotions may be sufficient to relieve symptoms. Prescription medications, such as corticosteroids or immunosuppressants, may be necessary in more severe cases. Avoiding triggers and irritants can also help prevent flare-ups of dermatitis.
Artificial Skin is a synthetic substitute or equivalent that is used to replace, support, or enhance the function of damaged or absent skin. It can be made from various materials such as biopolymers, composites, or biosynthetic materials. The main purpose of artificial skin is to provide a temporary or permanent covering for wounds, burns, or ulcers that cannot be healed with conventional treatments. Additionally, it may serve as a platform for the delivery of medications or as a matrix for the growth of cells and tissues during skin grafting procedures. Artificial skin must possess properties such as biocompatibility, durability, flexibility, and permeability to air and water vapor in order to promote optimal healing and minimize scarring.
A hair follicle is a part of the human skin from which hair grows. It is a complex organ that consists of several layers, including an outer root sheath, inner root sheath, and matrix. The hair follicle is located in the dermis, the second layer of the skin, and is surrounded by sebaceous glands and erector pili muscles.
The hair growth cycle includes three phases: anagen (growth phase), catagen (transitional phase), and telogen (resting phase). During the anagen phase, cells in the matrix divide rapidly to produce new hair fibers that grow out of the follicle. The hair fiber is made up of a protein called keratin, which also makes up the outer layers of the skin and nails.
Hair follicles are important for various biological functions, including thermoregulation, sensory perception, and social communication. They also play a role in wound healing and can serve as a source of stem cells that can differentiate into other cell types.
Skin neoplasms refer to abnormal growths or tumors in the skin that can be benign (non-cancerous) or malignant (cancerous). They result from uncontrolled multiplication of skin cells, which can form various types of lesions. These growths may appear as lumps, bumps, sores, patches, or discolored areas on the skin.
Benign skin neoplasms include conditions such as moles, warts, and seborrheic keratoses, while malignant skin neoplasms are primarily classified into melanoma, squamous cell carcinoma, and basal cell carcinoma. These three types of cancerous skin growths are collectively known as non-melanoma skin cancers (NMSCs). Melanoma is the most aggressive and dangerous form of skin cancer, while NMSCs tend to be less invasive but more common.
It's essential to monitor any changes in existing skin lesions or the appearance of new growths and consult a healthcare professional for proper evaluation and treatment if needed.
Melanocytes are specialized cells that produce, store, and transport melanin, the pigment responsible for coloring of the skin, hair, and eyes. They are located in the bottom layer of the epidermis (the outermost layer of the skin) and can also be found in the inner ear and the eye's retina. Melanocytes contain organelles called melanosomes, which produce and store melanin.
Melanin comes in two types: eumelanin (black or brown) and pheomelanin (red or yellow). The amount and type of melanin produced by melanocytes determine the color of a person's skin, hair, and eyes. Exposure to UV radiation from sunlight increases melanin production as a protective response, leading to skin tanning.
Melanocyte dysfunction or abnormalities can lead to various medical conditions, such as albinism (lack of melanin production), melasma (excessive pigmentation), and melanoma (cancerous growth of melanocytes).
Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.
"Skin physiological phenomena" is not a standard medical term with a specific definition. However, I can provide some information about the general concepts that might be encompassed by this term.
Physiological phenomena refer to the functions and processes that occur in living organisms. When it comes to the skin, there are many different physiological phenomena that take place, including:
1. Barrier function: The skin acts as a barrier to protect the body from external elements such as bacteria, viruses, chemicals, and UV radiation.
2. Temperature regulation: The skin helps regulate body temperature through sweat production and blood flow.
3. Sensation: The skin contains nerve endings that allow us to feel touch, pressure, pain, and temperature.
4. Vitamin D synthesis: The skin can produce vitamin D when exposed to sunlight.
5. Moisture regulation: The skin helps maintain the body's moisture balance by producing sweat and preventing water loss.
6. Immunological function: The skin plays a role in the immune system by providing a physical barrier and containing immune cells that help fight off infections.
7. Excretion: The skin eliminates waste products through sweat.
8. Wound healing: The skin has the ability to repair itself after injury, through a complex process involving inflammation, tissue regeneration, and remodeling.
Therefore, "skin physiological phenomena" could refer to any or all of these functions and processes that take place in the skin.
Oncogene proteins, viral, are cancer-causing proteins that are encoded by the genetic material (DNA or RNA) of certain viruses. These viral oncogenes can be acquired through infection with retroviruses, such as human immunodeficiency virus (HIV), human T-cell leukemia virus (HTLV), and certain types of papillomaviruses and polyomaviruses.
When these viruses infect host cells, they can integrate their genetic material into the host cell's genome, leading to the expression of viral oncogenes. These oncogenes may then cause uncontrolled cell growth and division, ultimately resulting in the formation of tumors or cancers. The process by which viruses contribute to cancer development is complex and involves multiple steps, including the alteration of signaling pathways that regulate cell proliferation, differentiation, and survival.
Examples of viral oncogenes include the v-src gene found in the Rous sarcoma virus (RSV), which causes chicken sarcoma, and the E6 and E7 genes found in human papillomaviruses (HPVs), which are associated with cervical cancer and other anogenital cancers. Understanding viral oncogenes and their mechanisms of action is crucial for developing effective strategies to prevent and treat virus-associated cancers.
A "cell line, transformed" is a type of cell culture that has undergone a stable genetic alteration, which confers the ability to grow indefinitely in vitro, outside of the organism from which it was derived. These cells have typically been immortalized through exposure to chemical or viral carcinogens, or by introducing specific oncogenes that disrupt normal cell growth regulation pathways.
Transformed cell lines are widely used in scientific research because they offer a consistent and renewable source of biological material for experimentation. They can be used to study various aspects of cell biology, including signal transduction, gene expression, drug discovery, and toxicity testing. However, it is important to note that transformed cells may not always behave identically to their normal counterparts, and results obtained using these cells should be validated in more physiologically relevant systems when possible.
Cell division is the process by which a single eukaryotic cell (a cell with a true nucleus) divides into two identical daughter cells. This complex process involves several stages, including replication of DNA, separation of chromosomes, and division of the cytoplasm. There are two main types of cell division: mitosis and meiosis.
Mitosis is the type of cell division that results in two genetically identical daughter cells. It is a fundamental process for growth, development, and tissue repair in multicellular organisms. The stages of mitosis include prophase, prometaphase, metaphase, anaphase, and telophase, followed by cytokinesis, which divides the cytoplasm.
Meiosis, on the other hand, is a type of cell division that occurs in the gonads (ovaries and testes) during the production of gametes (sex cells). Meiosis results in four genetically unique daughter cells, each with half the number of chromosomes as the parent cell. This process is essential for sexual reproduction and genetic diversity. The stages of meiosis include meiosis I and meiosis II, which are further divided into prophase, prometaphase, metaphase, anaphase, and telophase.
In summary, cell division is the process by which a single cell divides into two daughter cells, either through mitosis or meiosis. This process is critical for growth, development, tissue repair, and sexual reproduction in multicellular organisms.
A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.
Papillomavirus E7 proteins are small, viral regulatory proteins encoded by the E7 gene in papillomaviruses (HPVs). These proteins play a crucial role in the life cycle of HPVs and are associated with the development of various types of cancer, most notably cervical cancer.
The E7 protein functions as a transcriptional activator and can bind to and degrade the retinoblastoma protein (pRb), which is a tumor suppressor. By binding to and inactivating pRb, E7 promotes the expression of genes required for cell cycle progression, leading to uncontrolled cell growth and proliferation.
E7 proteins are also capable of inducing genetic alterations, such as chromosomal instability and DNA damage, which can contribute to the development of cancer. Additionally, E7 has been shown to inhibit apoptosis (programmed cell death) and promote angiogenesis (the formation of new blood vessels), further contributing to tumor growth and progression.
Overall, Papillomavirus E7 proteins are important oncogenic factors that play a central role in the development of HPV-associated cancers.
Papillomaviridae is a family of small, non-enveloped DNA viruses that primarily infect the epithelial cells of mammals, birds, and reptiles. The name "papillomavirus" comes from the Latin word "papilla," which means nipple or small projection, reflecting the characteristic wart-like growths (papillomas) that these viruses can cause in infected host tissues.
The family Papillomaviridae includes more than 200 distinct papillomavirus types, with each type being defined by its specific DNA sequence. Human papillomaviruses (HPVs), which are the most well-studied members of this family, are associated with a range of diseases, from benign warts and lesions to malignant cancers such as cervical, anal, penile, vulvar, and oropharyngeal cancers.
Papillomaviruses have a circular, double-stranded DNA genome that is approximately 8 kbp in size. The viral genome encodes several early (E) proteins involved in viral replication and oncogenesis, as well as late (L) proteins that form the viral capsid. The life cycle of papillomaviruses is tightly linked to the differentiation program of their host epithelial cells, with productive infection occurring primarily in the differentiated layers of the epithelium.
In summary, Papillomaviridae is a family of DNA viruses that infect epithelial cells and can cause a variety of benign and malignant diseases. Human papillomaviruses are a significant public health concern due to their association with several cancer types.
The mouth mucosa refers to the mucous membrane that lines the inside of the mouth, also known as the oral mucosa. It covers the tongue, gums, inner cheeks, palate, and floor of the mouth. This moist tissue is made up of epithelial cells, connective tissue, blood vessels, and nerve endings. Its functions include protecting the underlying tissues from physical trauma, chemical irritation, and microbial infections; aiding in food digestion by producing enzymes; and providing sensory information about taste, temperature, and texture.
The foreskin is a double-layered fold of skin that covers and protects the head (glans) of the penis. It is a normal part of male anatomy and varies in length and coverage from person to person. The inner layer of the foreskin is highly sensitive and contains a high concentration of nerve endings, which can contribute to sexual pleasure.
In some cases, the foreskin may become tight or difficult to retract (a condition known as phimosis), which can cause discomfort or pain during sexual activity or other activities that stretch the foreskin. In these cases, medical intervention may be necessary to alleviate the problem. Some people choose to undergo circumcision, a surgical procedure in which the foreskin is removed, for cultural, religious, or personal reasons. However, circumcision is not medically necessary for most people and carries some risks, such as infection, bleeding, and scarring.
Fibroblasts are specialized cells that play a critical role in the body's immune response and wound healing process. They are responsible for producing and maintaining the extracellular matrix (ECM), which is the non-cellular component present within all tissues and organs, providing structural support and biochemical signals for surrounding cells.
Fibroblasts produce various ECM proteins such as collagens, elastin, fibronectin, and laminins, forming a complex network of fibers that give tissues their strength and flexibility. They also help in the regulation of tissue homeostasis by controlling the turnover of ECM components through the process of remodeling.
In response to injury or infection, fibroblasts become activated and start to proliferate rapidly, migrating towards the site of damage. Here, they participate in the inflammatory response, releasing cytokines and chemokines that attract immune cells to the area. Additionally, they deposit new ECM components to help repair the damaged tissue and restore its functionality.
Dysregulation of fibroblast activity has been implicated in several pathological conditions, including fibrosis (excessive scarring), cancer (where they can contribute to tumor growth and progression), and autoimmune diseases (such as rheumatoid arthritis).
Skin diseases, also known as dermatological conditions, refer to any medical condition that affects the skin, which is the largest organ of the human body. These diseases can affect the skin's function, appearance, or overall health. They can be caused by various factors, including genetics, infections, allergies, environmental factors, and aging.
Skin diseases can present in many different forms, such as rashes, blisters, sores, discolorations, growths, or changes in texture. Some common examples of skin diseases include acne, eczema, psoriasis, dermatitis, fungal infections, viral infections, bacterial infections, and skin cancer.
The symptoms and severity of skin diseases can vary widely depending on the specific condition and individual factors. Some skin diseases are mild and can be treated with over-the-counter medications or topical creams, while others may require more intensive treatments such as prescription medications, light therapy, or even surgery.
It is important to seek medical attention if you experience any unusual or persistent changes in your skin, as some skin diseases can be serious or indicative of other underlying health conditions. A dermatologist is a medical doctor who specializes in the diagnosis and treatment of skin diseases.
The dermis is the layer of skin located beneath the epidermis, which is the outermost layer of the skin. It is composed of connective tissue and provides structure and support to the skin. The dermis contains blood vessels, nerves, hair follicles, sweat glands, and oil glands. It is also responsible for the production of collagen and elastin, which give the skin its strength and flexibility. The dermis can be further divided into two layers: the papillary dermis, which is the upper layer and contains finger-like projections called papillae that extend upwards into the epidermis, and the reticular dermis, which is the lower layer and contains thicker collagen bundles. Together, the epidermis and dermis make up the true skin.
Desmosomes are specialized intercellular junctions that provide strong adhesion between adjacent epithelial cells and help maintain the structural integrity and stability of tissues. They are composed of several proteins, including desmoplakin, plakoglobin, and cadherins, which form complex structures that anchor intermediate filaments (such as keratin) to the cell membrane. This creates a network of interconnected cells that can withstand mechanical stresses. Desmosomes are particularly abundant in tissues subjected to high levels of tension, such as the skin and heart.
Gene expression is the process by which the information encoded in a gene is used to synthesize a functional gene product, such as a protein or RNA molecule. This process involves several steps: transcription, RNA processing, and translation. During transcription, the genetic information in DNA is copied into a complementary RNA molecule, known as messenger RNA (mRNA). The mRNA then undergoes RNA processing, which includes adding a cap and tail to the mRNA and splicing out non-coding regions called introns. The resulting mature mRNA is then translated into a protein on ribosomes in the cytoplasm through the process of translation.
The regulation of gene expression is a complex and highly controlled process that allows cells to respond to changes in their environment, such as growth factors, hormones, and stress signals. This regulation can occur at various stages of gene expression, including transcriptional activation or repression, RNA processing, mRNA stability, and translation. Dysregulation of gene expression has been implicated in many diseases, including cancer, genetic disorders, and neurological conditions.
'Gene expression regulation' refers to the processes that control whether, when, and where a particular gene is expressed, meaning the production of a specific protein or functional RNA encoded by that gene. This complex mechanism can be influenced by various factors such as transcription factors, chromatin remodeling, DNA methylation, non-coding RNAs, and post-transcriptional modifications, among others. Proper regulation of gene expression is crucial for normal cellular function, development, and maintaining homeostasis in living organisms. Dysregulation of gene expression can lead to various diseases, including cancer and genetic disorders.
Transglutaminases are a family of enzymes that catalyze the post-translational modification of proteins by forming isopeptide bonds between the carboxamide group of peptide-bound glutamine residues and the ε-amino group of lysine residues. This process is known as transamidation or cross-linking. Transglutaminases play important roles in various biological processes, including cell signaling, differentiation, apoptosis, and tissue repair. There are several types of transglutaminases, such as tissue transglutaminase (TG2), factor XIII, and blood coagulation factor XIIIA. Abnormal activity or expression of these enzymes has been implicated in various diseases, such as celiac disease, neurodegenerative disorders, and cancer.
A papilloma is a benign (noncancerous) tumor that grows on a stalk, often appearing as a small cauliflower-like growth. It can develop in various parts of the body, but when it occurs in the mucous membranes lining the respiratory, digestive, or genitourinary tracts, they are called squamous papillomas. The most common type is the skin papilloma, which includes warts. They are usually caused by human papillomavirus (HPV) infection and can be removed through various medical procedures if they become problematic or unsightly.
Melanosomes are membrane-bound organelles found in melanocytes, the pigment-producing cells in the skin, hair, and eyes. They contain the pigment melanin, which is responsible for giving color to these tissues. Melanosomes are produced in the melanocyte and then transferred to surrounding keratinocytes in the epidermis via a process called cytocrinesis. There are four stages of melanosome development: stage I (immature), stage II (developing), stage III (mature), and stage IV (degrading). The amount and type of melanin in the melanosomes determine the color of an individual's skin, hair, and eyes. Mutations in genes involved in melanosome biogenesis or function can lead to various pigmentation disorders, such as albinism.
Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.
The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.
Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.
Pemphigus is a group of rare, autoimmune blistering diseases that affect the skin and mucous membranes. In these conditions, the immune system mistakenly produces antibodies against desmoglein proteins, which are crucial for maintaining cell-to-cell adhesion in the epidermis (outermost layer of the skin). This results in the loss of keratinocyte cohesion and formation of flaccid blisters filled with serous fluid.
There are several types of pemphigus, including:
1. Pemphigus vulgaris - The most common form, primarily affecting middle-aged to older adults, with widespread erosions and flaccid blisters on the skin and mucous membranes (e.g., mouth, nose, genitals).
2. Pemphigus foliaceus - A more superficial form, mainly involving the skin, causing crusted erosions and scaly lesions without mucosal involvement. It is more prevalent in older individuals and in certain geographical regions like the Middle East.
3. Paraneoplastic pemphigus - A rare type associated with underlying neoplasms (cancers), such as lymphomas or carcinomas, characterized by severe widespread blistering of both skin and mucous membranes, along with antibodies against additional antigens besides desmogleins.
4. IgA pemphigus - A less common form characterized by localized or generalized erosions and blisters, with IgA autoantibodies targeting the basement membrane zone.
Treatment for pemphigus typically involves high-dose systemic corticosteroids, often in combination with immunosuppressive agents (e.g., azathioprine, mycophenolate mofetil, rituximab) to control the disease activity and prevent complications. Regular follow-ups with dermatologists and oral specialists are essential for monitoring treatment response and managing potential side effects.
Apoptosis is a programmed and controlled cell death process that occurs in multicellular organisms. It is a natural process that helps maintain tissue homeostasis by eliminating damaged, infected, or unwanted cells. During apoptosis, the cell undergoes a series of morphological changes, including cell shrinkage, chromatin condensation, and fragmentation into membrane-bound vesicles called apoptotic bodies. These bodies are then recognized and engulfed by neighboring cells or phagocytic cells, preventing an inflammatory response. Apoptosis is regulated by a complex network of intracellular signaling pathways that involve proteins such as caspases, Bcl-2 family members, and inhibitors of apoptosis (IAPs).
"Hairless mice" is a term used to describe strains of laboratory mice that lack a functional fur coat. This condition is also known as "nude mice." The hairlessness in these mice is caused by a genetic mutation that results in the absence or underdevelopment of hair follicles and a weakened immune system.
Hairless mice are often used in scientific research because their impaired immune systems make them more susceptible to certain diseases, allowing researchers to study the progression and treatment of those conditions in a controlled environment. Additionally, their lack of fur makes it easier to observe and monitor skin conditions and wounds. These mice are also used as models for human diseases such as cancer, AIDS, and autoimmune disorders.
Cell proliferation is the process by which cells increase in number, typically through the process of cell division. In the context of biology and medicine, it refers to the reproduction of cells that makes up living tissue, allowing growth, maintenance, and repair. It involves several stages including the transition from a phase of quiescence (G0 phase) to an active phase (G1 phase), DNA replication in the S phase, and mitosis or M phase, where the cell divides into two daughter cells.
Abnormal or uncontrolled cell proliferation is a characteristic feature of many diseases, including cancer, where deregulated cell cycle control leads to excessive and unregulated growth of cells, forming tumors that can invade surrounding tissues and metastasize to distant sites in the body.
Cell movement, also known as cell motility, refers to the ability of cells to move independently and change their location within tissue or inside the body. This process is essential for various biological functions, including embryonic development, wound healing, immune responses, and cancer metastasis.
There are several types of cell movement, including:
1. **Crawling or mesenchymal migration:** Cells move by extending and retracting protrusions called pseudopodia or filopodia, which contain actin filaments. This type of movement is common in fibroblasts, immune cells, and cancer cells during tissue invasion and metastasis.
2. **Amoeboid migration:** Cells move by changing their shape and squeezing through tight spaces without forming protrusions. This type of movement is often observed in white blood cells (leukocytes) as they migrate through the body to fight infections.
3. **Pseudopodial extension:** Cells extend pseudopodia, which are temporary cytoplasmic projections containing actin filaments. These protrusions help the cell explore its environment and move forward.
4. **Bacterial flagellar motion:** Bacteria use a whip-like structure called a flagellum to propel themselves through their environment. The rotation of the flagellum is driven by a molecular motor in the bacterial cell membrane.
5. **Ciliary and ependymal movement:** Ciliated cells, such as those lining the respiratory tract and fallopian tubes, have hair-like structures called cilia that beat in coordinated waves to move fluids or mucus across the cell surface.
Cell movement is regulated by a complex interplay of signaling pathways, cytoskeletal rearrangements, and adhesion molecules, which enable cells to respond to environmental cues and navigate through tissues.
Fibroblast Growth Factor 7 (FGF-7), also known as Keratinocyte Growth Factor (KGF), is a protein that belongs to the fibroblast growth factor family. It plays an essential role in the regulation of cell growth, survival, and differentiation. Specifically, FGF-7/KGF primarily targets epithelial cells, including those found in the skin, lungs, and gastrointestinal tract. In the skin, FGF-7/KGF is produced by fibroblasts and stimulates the growth and migration of keratinocytes, which are crucial for wound healing and epidermal maintenance. Additionally, FGF-7/KGF has been implicated in various physiological and pathological processes, such as tissue repair, development, and cancer progression.
Cell adhesion refers to the binding of cells to extracellular matrices or to other cells, a process that is fundamental to the development, function, and maintenance of multicellular organisms. Cell adhesion is mediated by various cell surface receptors, such as integrins, cadherins, and immunoglobulin-like cell adhesion molecules (Ig-CAMs), which interact with specific ligands in the extracellular environment. These interactions lead to the formation of specialized junctions, such as tight junctions, adherens junctions, and desmosomes, that help to maintain tissue architecture and regulate various cellular processes, including proliferation, differentiation, migration, and survival. Disruptions in cell adhesion can contribute to a variety of diseases, including cancer, inflammation, and degenerative disorders.
Desmoglein 3 is a type of desmoglein protein that is primarily found in the upper layers of the epidermis, specifically in the desmosomes of the skin. Desmogleins are part of the cadherin family of cell adhesion molecules and play a crucial role in maintaining the structural integrity and cohesion of tissues, particularly in areas subjected to mechanical stress.
Desmoglein 3 is essential for the formation and maintenance of desmosomal junctions in stratified squamous epithelia, such as the skin and mucous membranes. It is involved in cell-to-cell adhesion by forming calcium-dependent homophilic interactions with other Desmoglein 3 molecules on adjacent cells.
Mutations in the gene encoding Desmoglein 3 have been associated with several skin disorders, including pemphigus vulgaris, a severe autoimmune blistering disease that affects the mucous membranes and skin. In pemphigus vulgaris, autoantibodies target Desmoglein 3 (and sometimes Desmoglein 1) molecules, leading to loss of cell-to-cell adhesion and formation of blisters and erosions.
Hemidesmosomes are specialized structures found in the cell membranes of epithelial cells that help to anchor them to the underlying basement membrane. They are composed of several proteins, including integrins and collagen type XVII, which interact with both intracellular keratin filaments and extracellular matrix components such as laminin-332. Hemidesmosomes play a crucial role in maintaining the integrity and stability of epithelial tissues by providing strong adhesive bonds between the epithelial cells and the underlying basement membrane, which is essential for normal tissue function and homeostasis. Mutations in genes encoding hemidesmosomal proteins can lead to various inherited skin blistering disorders, such as epidermolysis bullosa.
Protein precursors, also known as proproteins or prohormones, are inactive forms of proteins that undergo post-translational modification to become active. These modifications typically include cleavage of the precursor protein by specific enzymes, resulting in the release of the active protein. This process allows for the regulation and control of protein activity within the body. Protein precursors can be found in various biological processes, including the endocrine system where they serve as inactive hormones that can be converted into their active forms when needed.
A blister is a small fluid-filled bubble that forms on the skin due to friction, burns, or contact with certain chemicals or irritants. Blisters are typically filled with a clear fluid called serum, which is a component of blood. They can also be filled with blood (known as blood blisters) if the blister is caused by a more severe injury.
Blisters act as a natural protective barrier for the underlying skin and tissues, preventing infection and promoting healing. It's generally recommended to leave blisters intact and avoid breaking them, as doing so can increase the risk of infection and delay healing. If a blister is particularly large or painful, medical attention may be necessary to prevent complications.
Medically, hair is defined as a threadlike structure that grows from the follicles found in the skin of mammals. It is primarily made up of a protein called keratin and consists of three parts: the medulla (the innermost part or core), the cortex (middle layer containing keratin filaments) and the cuticle (outer layer of overlapping scales).
Hair growth occurs in cycles, with each cycle consisting of a growth phase (anagen), a transitional phase (catagen), and a resting phase (telogen). The length of hair is determined by the duration of the anagen phase.
While hair plays a crucial role in protecting the skin from external factors like UV radiation, temperature changes, and physical damage, it also serves as an essential aspect of human aesthetics and identity.
Up-regulation is a term used in molecular biology and medicine to describe an increase in the expression or activity of a gene, protein, or receptor in response to a stimulus. This can occur through various mechanisms such as increased transcription, translation, or reduced degradation of the molecule. Up-regulation can have important functional consequences, for example, enhancing the sensitivity or response of a cell to a hormone, neurotransmitter, or drug. It is a normal physiological process that can also be induced by disease or pharmacological interventions.
Atopic dermatitis is a chronic, inflammatory skin condition that is commonly known as eczema. It is characterized by dry, itchy, and scaly patches on the skin that can become red, swollen, and cracked over time. The condition often affects the skin on the face, hands, feet, and behind the knees, and it can be triggered or worsened by exposure to certain allergens, irritants, stress, or changes in temperature and humidity. Atopic dermatitis is more common in people with a family history of allergies, such as asthma or hay fever, and it often begins in infancy or early childhood. The exact cause of atopic dermatitis is not fully understood, but it is thought to involve a combination of genetic and environmental factors that affect the immune system and the skin's ability to maintain a healthy barrier function.
Intermediate filament proteins (IFPs) are a type of cytoskeletal protein that form the intermediate filaments (IFs), which are one of the three major components of the cytoskeleton in eukaryotic cells, along with microtubules and microfilaments. These proteins have a unique structure, characterized by an alpha-helical rod domain flanked by non-helical head and tail domains.
Intermediate filament proteins are classified into six major types based on their amino acid sequence: Type I (acidic) and Type II (basic) keratins, Type III (desmin, vimentin, glial fibrillary acidic protein, and peripherin), Type IV (neurofilaments), Type V (lamins), and Type VI (nestin). Each type of IFP has a distinct pattern of expression in different tissues and cell types.
Intermediate filament proteins play important roles in maintaining the structural integrity and mechanical strength of cells, providing resilience to mechanical stress, and regulating various cellular processes such as cell division, migration, and signal transduction. Mutations in IFP genes have been associated with several human diseases, including cancer, neurodegenerative disorders, and genetic skin fragility disorders.
Keratolytic agents are substances that cause the softening and sloughing off of excess keratin, the protein that makes up the outermost layer of the skin (stratum corneum). These agents help to break down and remove dead skin cells, increase moisture retention, and promote the growth of new skin cells. They are commonly used in the treatment of various dermatological conditions such as psoriasis, eczema, warts, calluses, and ichthyosis. Examples of keratolytic agents include salicylic acid, urea, lactic acid, and retinoic acid.
Keratin-1 is a type of keratin protein that is primarily expressed in the differentiated cells of epithelial tissues, such as the hair follicles and the outermost layer of the skin (epidermis). It is a structural protein that provides strength and rigidity to these cells. In the hair follicle, keratin-1 is found in the cortex of the hair shaft where it contributes to the hair's overall structure and stability. It is also a key component of the outermost layer of the skin (stratum corneum) where it helps to form a protective barrier against external stressors such as chemicals, microorganisms, and physical damage.
Sebaceous glands are microscopic, exocrine glands that are found in the dermis of mammalian skin. They are attached to hair follicles and produce an oily substance called sebum, which is composed of triglycerides, wax esters, squalene, and metabolites of fat-producing cells (fatty acids, cholesterol). Sebum is released through a duct onto the surface of the skin, where it forms a protective barrier that helps to prevent water loss, keeps the skin and hair moisturized, and has antibacterial properties.
Sebaceous glands are distributed throughout the body, but they are most numerous on the face, scalp, and upper trunk. They can also be found in other areas of the body such as the eyelids (where they are known as meibomian glands), the external ear canal, and the genital area.
Abnormalities in sebaceous gland function can lead to various skin conditions, including acne, seborrheic dermatitis, and certain types of skin cancer.
Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.
Beta-defensins are a group of small, cationic host defense peptides that play an important role in the innate immune system. They have broad-spectrum antimicrobial activity against various pathogens, including bacteria, fungi, and viruses. Beta-defensins are produced by epithelial cells, phagocytes, and other cell types in response to infection or inflammation. They function by disrupting the membranes of microbes, leading to their death. Additionally, beta-defensins can also modulate the immune response by recruiting immune cells to the site of infection and regulating inflammation. Mutations in beta-defensin genes have been associated with increased susceptibility to infectious diseases.
Non-fibrillar collagens are a type of collagen that do not form fibrous structures, unlike the more common fibrillar collagens. They are a group of structurally diverse collagens that play important roles in various biological processes such as cell adhesion, migration, and differentiation. Non-fibrillar collagens include types IV, VI, VIII, X, XII, XIV, XVI, XIX, XXI, and XXVIII. They are often found in basement membranes and other specialized extracellular matrix structures.
Type IV collagen is a major component of the basement membrane and forms a network-like structure that provides a scaffold for other matrix components. Type VI collagen has a beaded filament structure and is involved in the organization of the extracellular matrix. Type VIII collagen is found in the eyes and helps to maintain the structural integrity of the eye. Type X collagen is associated with cartilage development and bone formation. Type XII and XIV collagens are fibril-associated collagens that help to regulate the organization and diameter of fibrillar collagens. The other non-fibrillar collagens have various functions, including cell adhesion, migration, and differentiation.
Overall, non-fibrillar collagens are important structural components of the extracellular matrix and play critical roles in various biological processes.
Skin pigmentation is the coloration of the skin that is primarily determined by two types of melanin pigments, eumelanin and pheomelanin. These pigments are produced by melanocytes, which are specialized cells located in the epidermis. Eumelanin is responsible for brown or black coloration, while pheomelanin produces a red or yellow hue.
The amount and distribution of melanin in the skin can vary depending on genetic factors, age, sun exposure, and various other influences. Increased production of melanin in response to UV radiation from the sun helps protect the skin from damage, leading to darkening or tanning of the skin. However, excessive sun exposure can also cause irregular pigmentation, such as sunspots or freckles.
Abnormalities in skin pigmentation can result from various medical conditions, including albinism (lack of melanin production), vitiligo (loss of melanocytes leading to white patches), and melasma (excessive pigmentation often caused by hormonal changes). These conditions may require medical treatment to manage or improve the pigmentation issues.
Skin transplantation, also known as skin grafting, is a surgical procedure that involves the removal of healthy skin from one part of the body (donor site) and its transfer to another site (recipient site) that has been damaged or lost due to various reasons such as burns, injuries, infections, or diseases. The transplanted skin can help in healing wounds, restoring functionality, and improving the cosmetic appearance of the affected area. There are different types of skin grafts, including split-thickness grafts, full-thickness grafts, and composite grafts, which vary in the depth and size of the skin removed and transplanted. The success of skin transplantation depends on various factors, including the size and location of the wound, the patient's overall health, and the availability of suitable donor sites.
Integrin beta4, also known as ITGB4 or CD104, is a type of integrin subunit that forms part of the integrin receptor along with an alpha subunit. Integrins are transmembrane proteins involved in cell-cell and cell-extracellular matrix (ECM) adhesion, signal transduction, and regulation of various cellular processes such as proliferation, differentiation, and migration.
Integrin beta4 is unique among the integrin subunits because it has a large cytoplasmic domain that can interact with several intracellular signaling molecules, making it an important regulator of cell behavior. Integrin beta4 is widely expressed in various tissues, including epithelial cells, endothelial cells, and hematopoietic cells.
Integrin beta4 forms heterodimers with integrin alpha6 to form the receptor for laminins, which are major components of the basement membrane. This receptor is involved in maintaining the integrity of epithelial tissues and regulating cell migration during development, tissue repair, and cancer progression. Mutations in ITGB4 have been associated with several human diseases, including epidermolysis bullosa, a group of inherited skin disorders characterized by fragile skin and blistering.
Squamous cell carcinoma is a type of skin cancer that begins in the squamous cells, which are flat, thin cells that form the outer layer of the skin (epidermis). It commonly occurs on sun-exposed areas such as the face, ears, lips, and backs of the hands. Squamous cell carcinoma can also develop in other areas of the body including the mouth, lungs, and cervix.
This type of cancer usually develops slowly and may appear as a rough or scaly patch of skin, a red, firm nodule, or a sore or ulcer that doesn't heal. While squamous cell carcinoma is not as aggressive as some other types of cancer, it can metastasize (spread) to other parts of the body if left untreated, making early detection and treatment important.
Risk factors for developing squamous cell carcinoma include prolonged exposure to ultraviolet (UV) radiation from the sun or tanning beds, fair skin, a history of sunburns, a weakened immune system, and older age. Prevention measures include protecting your skin from the sun by wearing protective clothing, using a broad-spectrum sunscreen with an SPF of at least 30, avoiding tanning beds, and getting regular skin examinations.
Acantholysis is a medical term that refers to the separation of the cells in the upper layer of the skin (the epidermis), specifically between the pickle cell layer (stratum spinosum) and the granular cell layer (stratum granulosum). This separation results in the formation of distinct, round, or oval cells called acantholytic cells, which are typically seen in certain skin conditions.
Acantholysis is a characteristic feature of several skin disorders, including:
1. Pemphigus vulgaris: A rare autoimmune blistering disorder where the immune system produces antibodies against desmoglein-1 and -3 proteins, leading to acantholysis and formation of flaccid blisters.
2. Pemphigus foliaceus: Another autoimmune blistering disorder that specifically targets desmoglein-1 protein, causing superficial blisters and erosions on the skin.
3. Hailey-Hailey disease (familial benign chronic pemphigus): An autosomal dominant genetic disorder affecting ATP2C1 gene, leading to defective calcium transport and abnormal keratinocyte adhesion, resulting in acantholysis and recurrent skin eruptions.
4. Darier's disease (keratosis follicularis): An autosomal dominant genetic disorder affecting ATP2A2 gene, causing dysfunction of calcium transport and abnormal keratinocyte adhesion, resulting in acantholysis and characteristic papular or keratotic skin lesions.
5. Grover's disease (transient acantholytic dermatosis): An acquired skin disorder of unknown cause, characterized by the development of pruritic, red, and scaly papules and vesicles due to acantholysis.
The presence of acantholysis in these conditions can be confirmed through histopathological examination of skin biopsies.
Transgenic mice are genetically modified rodents that have incorporated foreign DNA (exogenous DNA) into their own genome. This is typically done through the use of recombinant DNA technology, where a specific gene or genetic sequence of interest is isolated and then introduced into the mouse embryo. The resulting transgenic mice can then express the protein encoded by the foreign gene, allowing researchers to study its function in a living organism.
The process of creating transgenic mice usually involves microinjecting the exogenous DNA into the pronucleus of a fertilized egg, which is then implanted into a surrogate mother. The offspring that result from this procedure are screened for the presence of the foreign DNA, and those that carry the desired genetic modification are used to establish a transgenic mouse line.
Transgenic mice have been widely used in biomedical research to model human diseases, study gene function, and test new therapies. They provide a valuable tool for understanding complex biological processes and developing new treatments for a variety of medical conditions.
Tetradecanoylphorbol acetate (TPA) is defined as a pharmacological agent that is a derivative of the phorbol ester family. It is a potent tumor promoter and activator of protein kinase C (PKC), a group of enzymes that play a role in various cellular processes such as signal transduction, proliferation, and differentiation. TPA has been widely used in research to study PKC-mediated signaling pathways and its role in cancer development and progression. It is also used in topical treatments for skin conditions such as psoriasis.
Promoter regions in genetics refer to specific DNA sequences located near the transcription start site of a gene. They serve as binding sites for RNA polymerase and various transcription factors that regulate the initiation of gene transcription. These regulatory elements help control the rate of transcription and, therefore, the level of gene expression. Promoter regions can be composed of different types of sequences, such as the TATA box and CAAT box, and their organization and composition can vary between different genes and species.
Transfection is a term used in molecular biology that refers to the process of deliberately introducing foreign genetic material (DNA, RNA or artificial gene constructs) into cells. This is typically done using chemical or physical methods, such as lipofection or electroporation. Transfection is widely used in research and medical settings for various purposes, including studying gene function, producing proteins, developing gene therapies, and creating genetically modified organisms. It's important to note that transfection is different from transduction, which is the process of introducing genetic material into cells using viruses as vectors.
Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:
Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.
Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.
Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.
Langerhans cells are specialized dendritic cells that are found in the epithelium, including the skin (where they are named after Paul Langerhans who first described them in 1868) and mucous membranes. They play a crucial role in the immune system as antigen-presenting cells, contributing to the initiation of immune responses.
These cells contain Birbeck granules, unique organelles that are involved in the transportation of antigens from the cell surface to the lysosomes for processing and presentation to T-cells. Langerhans cells also produce cytokines, which help regulate immune responses and attract other immune cells to the site of infection or injury.
It is important to note that although Langerhans cells are a part of the immune system, they can sometimes contribute to the development of certain skin disorders, such as allergic contact dermatitis and some forms of cancer, like Langerhans cell histiocytosis.
Neoplastic cell transformation is a process in which a normal cell undergoes genetic alterations that cause it to become cancerous or malignant. This process involves changes in the cell's DNA that result in uncontrolled cell growth and division, loss of contact inhibition, and the ability to invade surrounding tissues and metastasize (spread) to other parts of the body.
Neoplastic transformation can occur as a result of various factors, including genetic mutations, exposure to carcinogens, viral infections, chronic inflammation, and aging. These changes can lead to the activation of oncogenes or the inactivation of tumor suppressor genes, which regulate cell growth and division.
The transformation of normal cells into cancerous cells is a complex and multi-step process that involves multiple genetic and epigenetic alterations. It is characterized by several hallmarks, including sustained proliferative signaling, evasion of growth suppressors, resistance to cell death, enabling replicative immortality, induction of angiogenesis, activation of invasion and metastasis, reprogramming of energy metabolism, and evading immune destruction.
Neoplastic cell transformation is a fundamental concept in cancer biology and is critical for understanding the molecular mechanisms underlying cancer development and progression. It also has important implications for cancer diagnosis, prognosis, and treatment, as identifying the specific genetic alterations that underlie neoplastic transformation can help guide targeted therapies and personalized medicine approaches.
Epidermolysis Bullosa Simplex (EBS) is a group of genetic skin disorders characterized by the development of blisters and erosions on the skin following minor trauma or friction. It is caused by mutations in genes that encode proteins responsible for anchoring the epidermis (outer layer of the skin) to the dermis (inner layer of the skin).
There are several subtypes of EBS, which vary in severity and clinical presentation. The most common form is called "Dowling-Meara" EBS, which is characterized by blistering at or near birth, widespread blistering, and scarring. Other forms of EBS include "Weber-Cockayne" EBS, which is characterized by localized blistering and healing with minimal scarring, and "Kobner" EBS, which is characterized by blistering in response to heat or physical trauma.
Treatment for EBS typically involves wound care, prevention of infection, and pain management. In some cases, protein therapy or bone marrow transplantation may be considered as a treatment option. It's important to note that the prognosis for individuals with EBS varies depending on the severity and subtype of the disorder.
Human papillomavirus 16 (HPV16) is a specific type of human papillomavirus (HPV). HPV is a DNA virus that infects the skin and mucous membranes, and there are over 200 types of HPV. Some types of HPV can cause warts, while others are associated with an increased risk of certain cancers.
HPV16 is one of the high-risk types of HPV and is strongly associated with several types of cancer, including cervical, anal, penile, vulvar, and oropharyngeal (throat) cancers. HPV16 is responsible for about 50% of all cervical cancers and is the most common high-risk type of HPV found in these cancers.
HPV16 is typically transmitted through sexual contact, and most people who are sexually active will acquire at least one type of HPV at some point in their lives. While HPV infections are often harmless and clear up on their own without causing any symptoms or health problems, high-risk types like HPV16 can lead to cancer if left untreated.
Fortunately, there are vaccines available that protect against HPV16 and other high-risk types of HPV. These vaccines have been shown to be highly effective in preventing HPV-related cancers and precancerous lesions. The Centers for Disease Control and Prevention (CDC) recommends routine HPV vaccination for both boys and girls starting at age 11 or 12, although the vaccine can be given as early as age 9. Catch-up vaccinations are also recommended for older individuals who have not yet been vaccinated.
Epithelium is the tissue that covers the outer surface of the body, lines the internal cavities and organs, and forms various glands. It is composed of one or more layers of tightly packed cells that have a uniform shape and size, and rest on a basement membrane. Epithelial tissues are avascular, meaning they do not contain blood vessels, and are supplied with nutrients by diffusion from the underlying connective tissue.
Epithelial cells perform a variety of functions, including protection, secretion, absorption, excretion, and sensation. They can be classified based on their shape and the number of cell layers they contain. The main types of epithelium are:
1. Squamous epithelium: composed of flat, scalelike cells that fit together like tiles on a roof. It forms the lining of blood vessels, air sacs in the lungs, and the outermost layer of the skin.
2. Cuboidal epithelium: composed of cube-shaped cells with equal height and width. It is found in glands, tubules, and ducts.
3. Columnar epithelium: composed of tall, rectangular cells that are taller than they are wide. It lines the respiratory, digestive, and reproductive tracts.
4. Pseudostratified epithelium: appears stratified or layered but is actually made up of a single layer of cells that vary in height. The nuclei of these cells appear at different levels, giving the tissue a stratified appearance. It lines the respiratory and reproductive tracts.
5. Transitional epithelium: composed of several layers of cells that can stretch and change shape to accommodate changes in volume. It is found in the urinary bladder and ureters.
Epithelial tissue provides a barrier between the internal and external environments, protecting the body from physical, chemical, and biological damage. It also plays a crucial role in maintaining homeostasis by regulating the exchange of substances between the body and its environment.
Alopecia is a medical term that refers to the loss of hair or baldness. It can occur in various parts of the body, but it's most commonly used to describe hair loss from the scalp. Alopecia can have several causes, including genetics, hormonal changes, medical conditions, and aging.
There are different types of alopecia, such as:
* Alopecia Areata: It is a condition that causes round patches of hair loss on the scalp or other parts of the body. The immune system attacks the hair follicles, causing the hair to fall out.
* Androgenetic Alopecia: Also known as male pattern baldness or female pattern baldness, it's a genetic condition that causes gradual hair thinning and eventual hair loss, typically following a specific pattern.
* Telogen Effluvium: It is a temporary hair loss condition caused by stress, medication, pregnancy, or other factors that can cause the hair follicles to enter a resting phase, leading to shedding and thinning of the hair.
The treatment for alopecia depends on the underlying cause. In some cases, such as with telogen effluvium, hair growth may resume without any treatment. However, other forms of alopecia may require medical intervention, including topical treatments, oral medications, or even hair transplant surgery in severe cases.
Caspase-14 is a type of protease enzyme that belongs to the family of caspases, which are cysteine-aspartic acid proteases involved in the execution of apoptosis (programmed cell death) and inflammation. Caspase-14 is primarily expressed in the differentiated layers of the epidermis and plays a crucial role in keratinization, the process of forming an impermeable barrier to protect the body from external insults.
Caspase-14 is involved in the proteolytic processing of several structural proteins, such as loricrin, involucrin, and filaggrin, which are essential components of the cornified cell envelope, a structure that provides mechanical strength to the outermost layer of the skin. Additionally, caspase-14 has been implicated in the regulation of UV-induced apoptosis, contributing to the maintenance of skin homeostasis and preventing the development of skin cancers.
Defects or mutations in the CASP14 gene have been associated with several skin disorders, including dry skin, ichthyosis, and increased susceptibility to skin cancer.
Coculture techniques refer to a type of experimental setup in which two or more different types of cells or organisms are grown and studied together in a shared culture medium. This method allows researchers to examine the interactions between different cell types or species under controlled conditions, and to study how these interactions may influence various biological processes such as growth, gene expression, metabolism, and signal transduction.
Coculture techniques can be used to investigate a wide range of biological phenomena, including the effects of host-microbe interactions on human health and disease, the impact of different cell types on tissue development and homeostasis, and the role of microbial communities in shaping ecosystems. These techniques can also be used to test the efficacy and safety of new drugs or therapies by examining their effects on cells grown in coculture with other relevant cell types.
There are several different ways to establish cocultures, depending on the specific research question and experimental goals. Some common methods include:
1. Mixed cultures: In this approach, two or more cell types are simply mixed together in a culture dish or flask and allowed to grow and interact freely.
2. Cell-layer cultures: Here, one cell type is grown on a porous membrane or other support structure, while the second cell type is grown on top of it, forming a layered coculture.
3. Conditioned media cultures: In this case, one cell type is grown to confluence and its culture medium is collected and then used to grow a second cell type. This allows the second cell type to be exposed to any factors secreted by the first cell type into the medium.
4. Microfluidic cocultures: These involve growing cells in microfabricated channels or chambers, which allow for precise control over the spatial arrangement and flow of nutrients, waste products, and signaling molecules between different cell types.
Overall, coculture techniques provide a powerful tool for studying complex biological systems and gaining insights into the mechanisms that underlie various physiological and pathological processes.
Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) is a laboratory technique used in molecular biology to amplify and detect specific DNA sequences. This technique is particularly useful for the detection and quantification of RNA viruses, as well as for the analysis of gene expression.
The process involves two main steps: reverse transcription and polymerase chain reaction (PCR). In the first step, reverse transcriptase enzyme is used to convert RNA into complementary DNA (cDNA) by reading the template provided by the RNA molecule. This cDNA then serves as a template for the PCR amplification step.
In the second step, the PCR reaction uses two primers that flank the target DNA sequence and a thermostable polymerase enzyme to repeatedly copy the targeted cDNA sequence. The reaction mixture is heated and cooled in cycles, allowing the primers to anneal to the template, and the polymerase to extend the new strand. This results in exponential amplification of the target DNA sequence, making it possible to detect even small amounts of RNA or cDNA.
RT-PCR is a sensitive and specific technique that has many applications in medical research and diagnostics, including the detection of viruses such as HIV, hepatitis C virus, and SARS-CoV-2 (the virus that causes COVID-19). It can also be used to study gene expression, identify genetic mutations, and diagnose genetic disorders.
9,10-Dimethyl-1,2-benzanthracene (DMBA) is a synthetic, aromatic hydrocarbon that is commonly used in research as a carcinogenic compound. It is a potent tumor initiator and has been widely used to study chemical carcinogenesis in laboratory animals.
DMBA is a polycyclic aromatic hydrocarbon (PAH) with two benzene rings fused together, and two methyl groups attached at the 9 and 10 positions. This structure allows DMBA to intercalate into DNA, causing mutations that can lead to cancer.
Exposure to DMBA has been shown to cause a variety of tumors in different organs, depending on the route of administration and dose. In animal models, DMBA is often applied to the skin or administered orally to induce tumors in the mammary glands, lungs, or digestive tract.
It's important to note that DMBA is not a natural compound found in the environment and is used primarily for research purposes only. It should be handled with care and appropriate safety precautions due to its carcinogenic properties.
Epidermal Growth Factor (EGF) is a small polypeptide that plays a significant role in various biological processes, including cell growth, proliferation, differentiation, and survival. It primarily binds to the Epidermal Growth Factor Receptor (EGFR) on the surface of target cells, leading to the activation of intracellular signaling pathways that regulate these functions.
EGF is naturally produced in various tissues, such as the skin, and is involved in wound healing, tissue regeneration, and maintaining the integrity of epithelial tissues. In addition to its physiological roles, EGF has been implicated in several pathological conditions, including cancer, where it can contribute to tumor growth and progression by promoting cell proliferation and survival.
As a result, EGF and its signaling pathways have become targets for therapeutic interventions in various diseases, particularly cancer. Inhibitors of EGFR or downstream signaling components are used in the treatment of several types of malignancies, such as non-small cell lung cancer, colorectal cancer, and head and neck cancer.
Western blotting is a laboratory technique used in molecular biology to detect and quantify specific proteins in a mixture of many different proteins. This technique is commonly used to confirm the expression of a protein of interest, determine its size, and investigate its post-translational modifications. The name "Western" blotting distinguishes this technique from Southern blotting (for DNA) and Northern blotting (for RNA).
The Western blotting procedure involves several steps:
1. Protein extraction: The sample containing the proteins of interest is first extracted, often by breaking open cells or tissues and using a buffer to extract the proteins.
2. Separation of proteins by electrophoresis: The extracted proteins are then separated based on their size by loading them onto a polyacrylamide gel and running an electric current through the gel (a process called sodium dodecyl sulfate-polyacrylamide gel electrophoresis or SDS-PAGE). This separates the proteins according to their molecular weight, with smaller proteins migrating faster than larger ones.
3. Transfer of proteins to a membrane: After separation, the proteins are transferred from the gel onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric current in a process called blotting. This creates a replica of the protein pattern on the gel but now immobilized on the membrane for further analysis.
4. Blocking: The membrane is then blocked with a blocking agent, such as non-fat dry milk or bovine serum albumin (BSA), to prevent non-specific binding of antibodies in subsequent steps.
5. Primary antibody incubation: A primary antibody that specifically recognizes the protein of interest is added and allowed to bind to its target protein on the membrane. This step may be performed at room temperature or 4°C overnight, depending on the antibody's properties.
6. Washing: The membrane is washed with a buffer to remove unbound primary antibodies.
7. Secondary antibody incubation: A secondary antibody that recognizes the primary antibody (often coupled to an enzyme or fluorophore) is added and allowed to bind to the primary antibody. This step may involve using a horseradish peroxidase (HRP)-conjugated or alkaline phosphatase (AP)-conjugated secondary antibody, depending on the detection method used later.
8. Washing: The membrane is washed again to remove unbound secondary antibodies.
9. Detection: A detection reagent is added to visualize the protein of interest by detecting the signal generated from the enzyme-conjugated or fluorophore-conjugated secondary antibody. This can be done using chemiluminescent, colorimetric, or fluorescent methods.
10. Analysis: The resulting image is analyzed to determine the presence and quantity of the protein of interest in the sample.
Western blotting is a powerful technique for identifying and quantifying specific proteins within complex mixtures. It can be used to study protein expression, post-translational modifications, protein-protein interactions, and more. However, it requires careful optimization and validation to ensure accurate and reproducible results.
Benign familial pemphigus is a rare, autosomal dominant blistering disorder that primarily affects the mucous membranes. It is characterized by the presence of flaccid blisters and erosions on the skin and mucous membranes. The lesions are usually painless and heal without scarring.
The condition is caused by mutations in the desmoglein-1 (DSG1) gene, which provides instructions for making a protein called desmoglein 1. This protein is a component of desmosomes, which are structures that help bind cells together. Mutations in the DSG1 gene lead to the production of an abnormal desmoglein 1 protein, which disrupts the formation of desmosomes and causes the cells in the epidermis to separate from each other, resulting in blister formation.
Benign familial pemphigus is typically a milder form of pemphigus and has a good prognosis. Treatment usually involves the use of topical corticosteroids to reduce inflammation and promote healing of the lesions. In severe cases, systemic corticosteroids or other immunosuppressive medications may be necessary.
Desmoplakins are important proteins that play a crucial role in the structural integrity and function of certain types of cell-to-cell junctions called desmosomes. Desmosomes are specialized structures that connect adjacent cells in tissues that undergo significant mechanical stress, such as the skin, heart, and gut.
Desmoplakins are large proteins that are composed of several domains, including a plakin domain, which interacts with other desmosomal components, and a spectrin-like repeat domain, which binds to intermediate filaments. By linking desmosomes to the intermediate filament network, desmoplakins help to provide mechanical strength and stability to tissues.
Mutations in the genes that encode desmoplakins have been associated with several human genetic disorders, including arrhythmogenic right ventricular cardiomyopathy (ARVC), a heart condition characterized by abnormal heart rhythms and structural changes in the heart muscle, and epidermolysis bullosa simplex (EBS), a skin disorder characterized by blistering and fragility of the skin.
Cell survival refers to the ability of a cell to continue living and functioning normally, despite being exposed to potentially harmful conditions or treatments. This can include exposure to toxins, radiation, chemotherapeutic drugs, or other stressors that can damage cells or interfere with their normal processes.
In scientific research, measures of cell survival are often used to evaluate the effectiveness of various therapies or treatments. For example, researchers may expose cells to a particular drug or treatment and then measure the percentage of cells that survive to assess its potential therapeutic value. Similarly, in toxicology studies, measures of cell survival can help to determine the safety of various chemicals or substances.
It's important to note that cell survival is not the same as cell proliferation, which refers to the ability of cells to divide and multiply. While some treatments may promote cell survival, they may also inhibit cell proliferation, making them useful for treating diseases such as cancer. Conversely, other treatments may be designed to specifically target and kill cancer cells, even if it means sacrificing some healthy cells in the process.
DNA-binding proteins are a type of protein that have the ability to bind to DNA (deoxyribonucleic acid), the genetic material of organisms. These proteins play crucial roles in various biological processes, such as regulation of gene expression, DNA replication, repair and recombination.
The binding of DNA-binding proteins to specific DNA sequences is mediated by non-covalent interactions, including electrostatic, hydrogen bonding, and van der Waals forces. The specificity of binding is determined by the recognition of particular nucleotide sequences or structural features of the DNA molecule.
DNA-binding proteins can be classified into several categories based on their structure and function, such as transcription factors, histones, and restriction enzymes. Transcription factors are a major class of DNA-binding proteins that regulate gene expression by binding to specific DNA sequences in the promoter region of genes and recruiting other proteins to modulate transcription. Histones are DNA-binding proteins that package DNA into nucleosomes, the basic unit of chromatin structure. Restriction enzymes are DNA-binding proteins that recognize and cleave specific DNA sequences, and are widely used in molecular biology research and biotechnology applications.
Transcription factors are proteins that play a crucial role in regulating gene expression by controlling the transcription of DNA to messenger RNA (mRNA). They function by binding to specific DNA sequences, known as response elements, located in the promoter region or enhancer regions of target genes. This binding can either activate or repress the initiation of transcription, depending on the properties and interactions of the particular transcription factor. Transcription factors often act as part of a complex network of regulatory proteins that determine the precise spatiotemporal patterns of gene expression during development, differentiation, and homeostasis in an organism.
Keratin-15 is a type I keratin protein that is expressed in the basal cells of stratified epithelia, including the hair follicle and the epidermis. It plays a role in maintaining the integrity and stability of these tissues, particularly during periods of stress or injury. Keratin-15 has also been identified as a marker for stem cells in the hair follicle bulge region, which is responsible for hair regeneration. In addition, keratin-15 expression has been linked to various skin disorders, such as psoriasis and certain types of cancer, including squamous cell carcinoma.
Keratin-1
Junctional Epidermolysis Bullosa (JEB) is a rare genetic skin disorder characterized by the presence of blisters and erosions on the skin and mucous membranes. It results from a defect in one of the proteins that anchors the epidermis (the outermost layer of the skin) to the dermis (the underlying layer of connective tissue). This defect causes the layers to separate easily, leading to blistering with minor friction or trauma.
JEB is usually apparent at birth or within the first few months of life. The severity of the condition can vary widely, even among members of the same family. There are several subtypes of JEB, each caused by mutations in different genes. These include:
1. Herlitz JEB: This is the most severe form, often lethal in infancy. It's characterized by widespread blistering over the entire body, including the mucous membranes, and severe growth retardation.
2. Non-Herlitz JEB: Less severe than Herlitz JEB, this form can still cause significant disability. Blistering tends to be localized to specific areas of the body, such as the hands, feet, and knees.
3. JEB with Pyloric Atresia: This subtype includes gastrointestinal abnormalities like pyloric atresia (a blockage in the lower part of the stomach), in addition to skin fragility.
Treatment for JEB typically focuses on managing symptoms and preventing complications. This may involve wound care, prevention of infection, pain management, nutritional support, and physical therapy. There is currently no cure for JEB.
Keratin 5 is a type of keratin protein that is primarily expressed in the basal layer of epithelial tissues, including the skin, hair follicles, and nails. It forms heterodimers with keratin 14 and plays a crucial role in maintaining the structural integrity and stability of these tissues. Mutations in the gene that encodes keratin 5 (KRT5) can lead to several genetic disorders, such as epidermolysis bullosa simplex, which is characterized by blistering of the skin and mucous membranes.
A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.
Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.
During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.
Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.
Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.
Down-regulation is a process that occurs in response to various stimuli, where the number or sensitivity of cell surface receptors or the expression of specific genes is decreased. This process helps maintain homeostasis within cells and tissues by reducing the ability of cells to respond to certain signals or molecules.
In the context of cell surface receptors, down-regulation can occur through several mechanisms:
1. Receptor internalization: After binding to their ligands, receptors can be internalized into the cell through endocytosis. Once inside the cell, these receptors may be degraded or recycled back to the cell surface in smaller numbers.
2. Reduced receptor synthesis: Down-regulation can also occur at the transcriptional level, where the expression of genes encoding for specific receptors is decreased, leading to fewer receptors being produced.
3. Receptor desensitization: Prolonged exposure to a ligand can lead to a decrease in receptor sensitivity or affinity, making it more difficult for the cell to respond to the signal.
In the context of gene expression, down-regulation refers to the decreased transcription and/or stability of specific mRNAs, leading to reduced protein levels. This process can be induced by various factors, including microRNA (miRNA)-mediated regulation, histone modification, or DNA methylation.
Down-regulation is an essential mechanism in many physiological processes and can also contribute to the development of several diseases, such as cancer and neurodegenerative disorders.
Phosphorylation is the process of adding a phosphate group (a molecule consisting of one phosphorus atom and four oxygen atoms) to a protein or other organic molecule, which is usually done by enzymes called kinases. This post-translational modification can change the function, localization, or activity of the target molecule, playing a crucial role in various cellular processes such as signal transduction, metabolism, and regulation of gene expression. Phosphorylation is reversible, and the removal of the phosphate group is facilitated by enzymes called phosphatases.
Integrin α6 (also known as CD49f) is a type of integrin, which is a heterodimeric transmembrane receptor that mediates cell-cell and cell-extracellular matrix (ECM) interactions. Integrins play crucial roles in various biological processes such as cell adhesion, migration, proliferation, differentiation, and survival.
Integrin α6 is a 130 kDa glycoprotein that pairs with integrin β1, β4 or β5 to form three distinct heterodimeric complexes: α6β1, α6β4, and α6β5. Among these, the α6β4 integrin is the most extensively studied. It specifically binds to laminins in the basement membrane and plays essential roles in maintaining epithelial tissue architecture and function.
The α6β4 integrin has a unique structure with an extended cytoplasmic domain of β4 that can interact with intracellular signaling molecules, cytoskeletal proteins, and other adhesion receptors. This interaction allows the formation of stable adhesion complexes called hemidesmosomes, which anchor epithelial cells to the basement membrane and provide mechanical stability to tissues.
Mutations in integrin α6 or its partners can lead to various human diseases, including epidermolysis bullosa, a group of inherited skin disorders characterized by fragile skin and mucous membranes that blister and tear easily.
Lamellar Ichthyosis is a rare, inherited genetic skin disorder characterized by widespread, persistent scaling of the skin. It is caused by mutations in genes responsible for maintaining the barrier function and hydration of the skin. The condition is present from birth and can vary in severity.
In lamellar ichthyosis, the skin cells do not shed properly and instead accumulate in plates or scales that cover the entire body. These scales are large, dark brown or gray, and have a cracked appearance, resembling fish scales. The scales may be present at birth (congenital) or develop within the first few weeks of life.
The skin is also prone to redness, irritation, and infection due to the impaired barrier function. Other symptoms can include overheating, dehydration, and difficulty with sweating. The condition may improve in warmer, more humid environments.
Treatment for lamellar ichthyosis is aimed at managing symptoms and preventing complications. This may include topical creams and ointments to moisturize the skin, medications to reduce inflammation and infection, and avoiding environmental triggers that can worsen symptoms. In some cases, oral retinoids may be prescribed to help regulate skin cell growth and shedding.
Repressor proteins are a type of regulatory protein in molecular biology that suppress the transcription of specific genes into messenger RNA (mRNA) by binding to DNA. They function as part of gene regulation processes, often working in conjunction with an operator region and a promoter region within the DNA molecule. Repressor proteins can be activated or deactivated by various signals, allowing for precise control over gene expression in response to changing cellular conditions.
There are two main types of repressor proteins:
1. DNA-binding repressors: These directly bind to specific DNA sequences (operator regions) near the target gene and prevent RNA polymerase from transcribing the gene into mRNA.
2. Allosteric repressors: These bind to effector molecules, which then cause a conformational change in the repressor protein, enabling it to bind to DNA and inhibit transcription.
Repressor proteins play crucial roles in various biological processes, such as development, metabolism, and stress response, by controlling gene expression patterns in cells.
Desmogleins are a group of proteins that are part of the desmosomes, which are structures that help to strengthen and maintain the integrity of epithelial tissues. Desmogleins play a crucial role in cell-to-cell adhesion by forming intercellular junctions known as desmoglein adherens junctions. These junctions help to anchor intermediate filaments, such as keratin, to the plasma membrane and provide structural support to epithelial cells.
There are four main types of desmogleins (Dsg1-4), each with distinct expression patterns in different tissues. For example, Dsg1 is primarily expressed in the upper layers of the epidermis, while Dsg3 is found in the lower layers and in mucous membranes. Mutations in desmoglein genes have been associated with several skin disorders, including pemphigus vulgaris and pemphigus foliaceus, which are autoimmune blistering diseases characterized by the loss of cell-to-cell adhesion in the epidermis.
Skin aging, also known as cutaneous aging, is a complex and multifactorial process characterized by various visible changes in the skin's appearance and function. It can be divided into two main types: intrinsic (chronological or natural) aging and extrinsic (environmental) aging.
Intrinsic aging is a genetically determined and time-dependent process that results from internal factors such as cellular metabolism, hormonal changes, and genetic predisposition. The primary features of intrinsic aging include gradual thinning of the epidermis and dermis, decreased collagen and elastin production, reduced skin cell turnover, and impaired wound healing. Clinically, these changes present as fine wrinkles, dryness, loss of elasticity, and increased fragility of the skin.
Extrinsic aging, on the other hand, is caused by external factors such as ultraviolet (UV) radiation, pollution, smoking, alcohol consumption, and poor nutrition. Exposure to these environmental elements leads to oxidative stress, inflammation, and DNA damage, which accelerate the aging process. The main features of extrinsic aging are coarse wrinkles, pigmentary changes (e.g., age spots, melasma), irregular texture, skin laxity, and increased risk of developing skin cancers.
It is important to note that intrinsic and extrinsic aging processes often interact and contribute to the overall appearance of aged skin. A comprehensive approach to skincare should address both types of aging to maintain healthy and youthful-looking skin.
Interleukin-8 (IL-8) is a type of cytokine, which is a small signaling protein involved in immune response and inflammation. IL-8 is also known as neutrophil chemotactic factor or NCF because it attracts neutrophils, a type of white blood cell, to the site of infection or injury.
IL-8 is produced by various cells including macrophages, epithelial cells, and endothelial cells in response to bacterial or inflammatory stimuli. It acts by binding to specific receptors called CXCR1 and CXCR2 on the surface of neutrophils, which triggers a series of intracellular signaling events leading to neutrophil activation, migration, and degranulation.
IL-8 plays an important role in the recruitment of neutrophils to the site of infection or tissue damage, where they can phagocytose and destroy invading microorganisms. However, excessive or prolonged production of IL-8 has been implicated in various inflammatory diseases such as chronic obstructive pulmonary disease (COPD), rheumatoid arthritis, and cancer.
Epithelial cells are types of cells that cover the outer surfaces of the body, line the inner surfaces of organs and glands, and form the lining of blood vessels and body cavities. They provide a protective barrier against the external environment, regulate the movement of materials between the internal and external environments, and are involved in the sense of touch, temperature, and pain. Epithelial cells can be squamous (flat and thin), cuboidal (square-shaped and of equal height), or columnar (tall and narrow) in shape and are classified based on their location and function.
Tumor suppressor protein p53, also known as p53 or tumor protein p53, is a nuclear phosphoprotein that plays a crucial role in preventing cancer development and maintaining genomic stability. It does so by regulating the cell cycle and acting as a transcription factor for various genes involved in apoptosis (programmed cell death), DNA repair, and cell senescence (permanent cell growth arrest).
In response to cellular stress, such as DNA damage or oncogene activation, p53 becomes activated and accumulates in the nucleus. Activated p53 can then bind to specific DNA sequences and promote the transcription of target genes that help prevent the proliferation of potentially cancerous cells. These targets include genes involved in cell cycle arrest (e.g., CDKN1A/p21), apoptosis (e.g., BAX, PUMA), and DNA repair (e.g., GADD45).
Mutations in the TP53 gene, which encodes p53, are among the most common genetic alterations found in human cancers. These mutations often lead to a loss or reduction of p53's tumor suppressive functions, allowing cancer cells to proliferate uncontrollably and evade apoptosis. As a result, p53 has been referred to as "the guardian of the genome" due to its essential role in preventing tumorigenesis.
Cell culture is a technique used in scientific research to grow and maintain cells from plants, animals, or humans in a controlled environment outside of their original organism. This environment typically consists of a sterile container called a cell culture flask or plate, and a nutrient-rich liquid medium that provides the necessary components for the cells' growth and survival, such as amino acids, vitamins, minerals, and hormones.
There are several different types of cell culture techniques used in research, including:
1. Adherent cell culture: In this technique, cells are grown on a flat surface, such as the bottom of a tissue culture dish or flask. The cells attach to the surface and spread out, forming a monolayer that can be observed and manipulated under a microscope.
2. Suspension cell culture: In suspension culture, cells are grown in liquid medium without any attachment to a solid surface. These cells remain suspended in the medium and can be agitated or mixed to ensure even distribution of nutrients.
3. Organoid culture: Organoids are three-dimensional structures that resemble miniature organs and are grown from stem cells or other progenitor cells. They can be used to study organ development, disease processes, and drug responses.
4. Co-culture: In co-culture, two or more different types of cells are grown together in the same culture dish or flask. This technique is used to study cell-cell interactions and communication.
5. Conditioned medium culture: In this technique, cells are grown in a medium that has been conditioned by previous cultures of other cells. The conditioned medium contains factors secreted by the previous cells that can influence the growth and behavior of the new cells.
Cell culture techniques are widely used in biomedical research to study cellular processes, develop drugs, test toxicity, and investigate disease mechanisms. However, it is important to note that cell cultures may not always accurately represent the behavior of cells in a living organism, and results from cell culture experiments should be validated using other methods.
Allergic contact dermatitis is a type of inflammatory skin reaction that occurs when the skin comes into contact with a substance (allergen) that the immune system recognizes as foreign and triggers an allergic response. This condition is characterized by redness, itching, swelling, blistering, and cracking of the skin, which usually develops within 24-48 hours after exposure to the allergen. Common allergens include metals (such as nickel), rubber, medications, fragrances, and cosmetics. It is important to note that a person must first be sensitized to the allergen before developing an allergic response upon subsequent exposures.
A "knockout" mouse is a genetically engineered mouse in which one or more genes have been deleted or "knocked out" using molecular biology techniques. This allows researchers to study the function of specific genes and their role in various biological processes, as well as potential associations with human diseases. The mice are generated by introducing targeted DNA modifications into embryonic stem cells, which are then used to create a live animal. Knockout mice have been widely used in biomedical research to investigate gene function, disease mechanisms, and potential therapeutic targets.
Enzyme activation refers to the process by which an enzyme becomes biologically active and capable of carrying out its specific chemical or biological reaction. This is often achieved through various post-translational modifications, such as proteolytic cleavage, phosphorylation, or addition of cofactors or prosthetic groups to the enzyme molecule. These modifications can change the conformation or structure of the enzyme, exposing or creating a binding site for the substrate and allowing the enzymatic reaction to occur.
For example, in the case of proteolytic cleavage, an inactive precursor enzyme, known as a zymogen, is cleaved into its active form by a specific protease. This is seen in enzymes such as trypsin and chymotrypsin, which are initially produced in the pancreas as inactive precursors called trypsinogen and chymotrypsinogen, respectively. Once they reach the small intestine, they are activated by enteropeptidase, a protease that cleaves a specific peptide bond, releasing the active enzyme.
Phosphorylation is another common mechanism of enzyme activation, where a phosphate group is added to a specific serine, threonine, or tyrosine residue on the enzyme by a protein kinase. This modification can alter the conformation of the enzyme and create a binding site for the substrate, allowing the enzymatic reaction to occur.
Enzyme activation is a crucial process in many biological pathways, as it allows for precise control over when and where specific reactions take place. It also provides a mechanism for regulating enzyme activity in response to various signals and stimuli, such as hormones, neurotransmitters, or changes in the intracellular environment.
The Fluorescent Antibody Technique (FAT) is a type of immunofluorescence assay used in laboratory medicine and pathology for the detection and localization of specific antigens or antibodies in tissues, cells, or microorganisms. In this technique, a fluorescein-labeled antibody is used to selectively bind to the target antigen or antibody, forming an immune complex. When excited by light of a specific wavelength, the fluorescein label emits light at a longer wavelength, typically visualized as green fluorescence under a fluorescence microscope.
The FAT is widely used in diagnostic microbiology for the identification and characterization of various bacteria, viruses, fungi, and parasites. It has also been applied in the diagnosis of autoimmune diseases and certain cancers by detecting specific antibodies or antigens in patient samples. The main advantage of FAT is its high sensitivity and specificity, allowing for accurate detection and differentiation of various pathogens and disease markers. However, it requires specialized equipment and trained personnel to perform and interpret the results.
BALB/c is an inbred strain of laboratory mouse that is widely used in biomedical research. The strain was developed at the Institute of Cancer Research in London by Henry Baldwin and his colleagues in the 1920s, and it has since become one of the most commonly used inbred strains in the world.
BALB/c mice are characterized by their black coat color, which is determined by a recessive allele at the tyrosinase locus. They are also known for their docile and friendly temperament, making them easy to handle and work with in the laboratory.
One of the key features of BALB/c mice that makes them useful for research is their susceptibility to certain types of tumors and immune responses. For example, they are highly susceptible to developing mammary tumors, which can be induced by chemical carcinogens or viral infection. They also have a strong Th2-biased immune response, which makes them useful models for studying allergic diseases and asthma.
BALB/c mice are also commonly used in studies of genetics, neuroscience, behavior, and infectious diseases. Because they are an inbred strain, they have a uniform genetic background, which makes it easier to control for genetic factors in experiments. Additionally, because they have been bred in the laboratory for many generations, they are highly standardized and reproducible, making them ideal subjects for scientific research.
Keratinocyte
Keratinocyte transglutaminase
Keratinocyte growth factor
Allogeneic cultured keratinocytes and fibroblasts in bovine collagen
Allogeneic cultured keratinocytes and dermal fibroblasts in murine collagen
Formyl peptide receptor 1
Graziella Pellegrini
Squamous-cell carcinoma
Papillomaviridae
Wound healing
Topical steroid withdrawal
PTPRK
Skin sloughing
FGF7
Collagen, type XVII, alpha 1
Cannabinoid receptor
Toxic epidermal necrolysis
Stratum spinosum
Skin whitening
Electrotaxis
Methylparaben
Collagen, type XXIII, alpha 1
Interleukin-20 receptor
TRPV3
S100A11
SLURP1
Apolipoprotein D
Tissue engineering
Fiona Watt
Paracytophagy
Keratinocyte - Wikipedia
keratinocyte | Encyclopedia.com
Study unlocks the healing power of oral keratinocytes
Primary Gingival Keratinocytes - PCS-200-014 | ATCC
Effects of millimeter wave on gene expression in human keratinocytes]
Keratinocytes - Medical Dictionary online-medical-dictionary.org
abnormal keratinocyte physiology Mammalian Phenotype Term (MP:0003453)
In Vitro and In Vivo Transfer of bcl-2 Gene into Keratinocytes Suppresses UVB-induced Apoptosis¶
Keratinocyte carcinoma as an occupational disease | Occupational & Environmental Medicine
Tanshinone IIA Inhibits Growth of Keratinocytes through Cell Cycle Arrest and Apoptosis: Underlying Treatment Mechanism of...
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Immortalized Human Neonatal Foreskin Keratinocytes (HKc16E6/E7-II) | T0726 | ABMGood
Paeoniflorin attenuates ultraviolet B-induced apoptosis in human keratinocytes by inhibiting the ROS-p38-p53 pathway
British Library EThOS: Molecular changes involved in oral cancer progression and their relevance to keratinocyte immortalisation
Learning a Markov logic network for supervised gene regulation inference: application to the ID2 regulatory network in human...
"The anti proliferative effects of rosemary oil on keratinocyte cell li" by MUHAMMET KUDDUSİ ERHAN
Download: RNA quantification Sorted Mouse Keratinocyte Stem Cells at Karolinska institute | Application Note | pdf | 395673
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Extracellular group A Streptococcus induces keratinocyte apoptosis by dysregulating calcium signalling | Lund University...
AID 1621019 - Inhibition of transglutaminase in human keratinocytes assessed as mean transglutaminase activity level at 1.63 10...
Human Epidermal Keratinocytes-fetal
Photobiomodulation of Human Fibroblasts and Keratinocytes with Blue Light: Implications in Wound Healing[v1] | Preprints.org
Keratinocyte-Specific Ablation of RIPK4 Allows Epidermal Cornification but Impairs Skin Barrier Formation
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Keratinocyte | Cell Applications
Epidermal12
- Keratinocytes differentiate from epidermal stem cells in the lower part of the epidermis and migrate towards the surface, finally becoming corneocytes and eventually be shed off, which happens every 40 to 56 days in humans. (wikipedia.org)
- During this differentiation process, keratinocytes permanently withdraw from the cell cycle, initiate expression of epidermal differentiation markers, and move suprabasally as they become part of the stratum spinosum, stratum granulosum, and eventually corneocytes in the stratum corneum. (wikipedia.org)
- These factors include: The transcription factor p63, which prevents epidermal stem cells from differentiating into keratinocytes. (wikipedia.org)
- The transcriptome of p63 mutant keratinocytes deviated from the normal epidermal cell identity. (wikipedia.org)
- A recent study, published in FEBS Open Bio , elucidated the role of the epidermal growth factor (EGF) and its downstream signaling cascade in controlling the behavior of oral keratinocytes. (news-medical.net)
- However, this study, conducted by a team of researchers based at the Division of Biomimetics, Faculty of Dentistry & Graduate School of Medical and Dental Sciences, Niigata University, Japan, highlights the significant involvement of the epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) axis and its downstream signaling cascade, particularly Src/PI3K/Akt/mTOR, in the modulation of oral keratinocyte cell motility and proliferative capacity. (news-medical.net)
- Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell , spinous or prickle cell, and the granular cell. (online-medical-dictionary.org)
- Keratinocyte-Specific Ablation of RIPK4 Allows Epidermal Cornification but Impairs Skin Barrier Formation," JOURNAL OF INVESTIGATIVE DERMATOLOGY , vol. 138, no. 6, pp. 1268-1278, 2018. (ugent.be)
- The air-exposed culture of keratinocytes on dead de-epidermized dermis is one of the best models of in vitro epidermal differentiation known at the moment. (medicaljournals.se)
- We used subcultured epidermal keratinocytes originating from normal and ichthyotic patients. (medicaljournals.se)
- Once they reach the stratum corneum, they are fully differentiated keratinocytes devoid of nuclei and are subsequently shed in the process of epidermal turnover. (medscape.com)
- Redox cycling of phenol induces oxidative stress in human epidermal keratinocytes. (cdc.gov)
HaCaT9
- To explore the effect of millimeter wave exposure at low power density on gene expression in human keratinocytes (HaCaT). (nih.gov)
- HaCaT keratinocytes were exposed to 30.16 GHz millimeter wave with power densities of 1.0 or 3.5 mW/cm2 for 30 min per day. (nih.gov)
- We investigated the effects of various concentrations of Tan IIA (5-10 μ g/mL) on mouse keratinocytes and human HaCat cells in vitro to confirm this hypothesis. (hindawi.com)
- Immortalized keratinocytes HaCaT are often used as an analogue of NHK since they have a number of advantages over the latter - they do not require the presence of growth and differentiation factors in the medium, have unlimited potential for proliferation, demonstrate stable phenotype regardless of the number of passages (Colombo et al. (mendeley.com)
- 1988). However, HaCaT keratinocytes have key properties similar to NHK. (mendeley.com)
- 2003). Taking into account the properties and characteristics of the HaCaT line, these cells can be considered as a promising experimental model for research various physiological processes occurring in human keratinocytes. (mendeley.com)
- Silencing of Bach1 strongly increased HO-1 levels in HaCaT transformed keratinocytes and these HO-1 levels were not further increased by either UVA irradiation or silencing of HO-2. (bath.ac.uk)
- Effects and Stress-Relieving Mechanisms of Dark Tea Polysaccharide in Human HaCaT Keratinocytes and SZ95 Sebocytes. (bvsalud.org)
- The effects of dark tea polysaccharide (DTP) on stress-induced skin problems and its mechanism of action were investigated by modeling cortisone -induced stress injury in human HaCaT keratinocytes and SZ95 sebaceous gland cells . (bvsalud.org)
Induces4
- Those elevations of extracellular calcium concentrations induces an increase in intracellular free calcium concentrations in keratinocytes. (wikipedia.org)
- Ultraviolet B (UVB) irradiation induces apoptosis of keratinocytes that is known as "sunburn cells. (bioone.org)
- Previously we reported that UVB irradiation induces apoptosis accompanied by sequential activation of caspase 8, 3 and 1 in keratinocytes, and that the process is inhibited by various caspase inhibitors. (bioone.org)
- Ultraviolet A (UVA) radiation is an oxidizing agent that strongly induces the heme oxygenase 1(HO-1) expression in cultured human skin fibroblasts, but weakly induces it in skin keratinocytes. (bath.ac.uk)
Fibroblasts5
- SALPs inhibited LP-induced phosphorylation of NF-κB p65 and p38 MAPK and reduced cytokine release and gene expression in primary human keratinocytes and dermal fibroblasts. (nature.com)
- Here we present a study aiming at evidencing the effects of blue light on the proliferation and metabolism in fibroblasts and keratinocytes. (preprints.org)
- In conclusion, we observed that the blue LED light can be used to modulate the activity of human fibroblasts, and the effects in wound healing are particularly evident when studying the fibroblasts and keratinocytes co-cultures. (preprints.org)
- I am new at looking at photo-biomodulation, and have recently started to try to do this in skin cells (keratinocytes, fibroblasts and endothelial cells from donor biopsies). (preprints.org)
- Here, we report that low basal levels of HO- 1 and much higher basal levels of HO-2 protein were observed in keratinocytes compared with fibroblasts. (bath.ac.uk)
Apoptosis7
- The aim of the present investigation was to elucidate the cellular mechanisms whereby Tanshinone IIA (Tan IIA) leads to cell cycle arrest and apoptosis in vitro in keratinocytes, the target cells in psoriasis. (hindawi.com)
- Tan IIA inhibited proliferation of mouse keratinocytes in a dose- and time-dependent manner and induced apoptosis, resulting in S phase arrest accompanied by down-regulation of pCdk2 and cyclin A protein expression. (hindawi.com)
- There was also no translocation of apoptosis-inducing factor (AIF) from mitochondria to the nucleus in apoptotic keratinocytes, indicating Tan IIA-induced apoptosis occurs mainly through the caspase pathway. (hindawi.com)
- In addition, cell death analysis indicated that PF treatment markedly reduced UV‑B‑radiation‑induced apoptosis in keratinocytes, which was accompanied by increased procaspase 3 expression and decreased cleaved caspase 3 expression. (spandidos-publications.com)
- We now report an alternate mechanism of GAS-mediated apoptosis of primary human keratinocytes, initiated by extracellular GAS and involving dysregulation of intracellular calcium to produce endoplasmic reticulum stress. (lu.se)
- Induction of keratinocyte apoptosis by wild-type GAS was accompanied by cell detachment and loss of epithelial integrity, a phenomenon not observed with GAS deficient in capsule or SLO. (lu.se)
- We propose that cell signalling initiated by extracellular GAS compromises the epithelial barrier by inducing premature keratinocyte differentiation and apoptosis, thereby facilitating GAS invasion of deeper tissues. (lu.se)
Layers of the epidermis2
- Pathogens invading the upper layers of the epidermis can cause keratinocytes to produce proinflammatory mediators, particularly chemokines such as CXCL10 and CCL2 (MCP-1) which attract monocytes, natural killer cells, T-lymphocytes, and dendritic cells to the site of pathogen invasion. (wikipedia.org)
- Keratinocytes migrate from the deeper layers of the epidermis and are finally shed from the surface of the skin. (encyclopedia.com)
Proliferation of keratinocytes2
- Excessive proliferation of keratinocytes, abnormalities in the differentiation process, and continuous shedding of the thickened epidermis are characteristics of psoriasis (Figures 1 (a) and 1 (b)) [ 2 ]. (hindawi.com)
- In contrast, SALPs did not affect proliferation of keratinocytes. (nature.com)
Cells15
- Basal cells in the basal layer (stratum basale) of the skin are sometimes referred to as basal keratinocytes. (wikipedia.org)
- The fully cornified keratinocytes that form the outermost layer are constantly shed off and replaced by new cells. (wikipedia.org)
- In humans, it is estimated that keratinocytes turn over from stem cells to desquamation every 40-56 days, whereas in mice the estimated turnover time is 8-10 days. (wikipedia.org)
- Keratinocytes are the only cells in the body with the entire vitamin D metabolic pathway from vitamin D production to catabolism and vitamin D receptor expression. (wikipedia.org)
- keratinocyte (ke- rat -in-ŏ-syt) n. a type of cell that makes up 95% of the cells of the epidermis. (encyclopedia.com)
- Human cells from the immortalized nontumorigenic keratinocyte cell line were seeded at a concentration of 5000 cells/well on 96 well plates. (tubitak.gov.tr)
- However, unlike normal keratinocytes, the cells did not grow as compact colonies and did not stratify or undergo terminal differentiation, even after TPA treatment or suspension culture. (rupress.org)
- The ndk cells also differed from normal keratinocytes in that they did not require a feeder layer and were not stimulated by cholera toxin to proliferate. (rupress.org)
- We suggest that these cells are a useful experimental adjunct to cultures of normal keratinocytes, in which proliferation and terminal differentiation are tightly coordinated, because in ndk cells there appears to be a block in terminal differentiation. (rupress.org)
- hTert-Human Dermal Keratinocytes were selected with 2ug/ml puromycin after being infected by lentiviral particles expressing hTert under the control of CMV and hTert-Human Dermal Keratinocytes are shipped in frozen vials (the cells are provided @ passage 3). (angioproteomie.com)
- Human Keratinocyte Growth Medium (KGM, cAP-67) is recommended for cell culture and these cells have a minimum average population doubling levels >40 when cultured following the detailed protocol described below). (angioproteomie.com)
- AcceGen's HighQC™ Rat Keratinocyte Stem Cells were derived from Rat Skin. (accegen.com)
- They were maintained in AcceGen's Rat Keratinocyte Stem Cells Medium Kit. (accegen.com)
- This is consistent with the conclusion that high constitutive levels of HO-2 expression in keratinocytes are responsible for the resistance of these cells to HO-1 induction by UVA radiation and that Bach1 plays a predominant role in influencing the lack of HO-1 expression in keratinocytes. (bath.ac.uk)
- Aim: To detect the expression of molecules associated with Notch signaling pathway in stem cells from human exfoliated deciduous teeth (SHED) cultured in specific differentiation medium, namely, keratinocyte growth medium (KGM). (bvsalud.org)
Oral keratinocyte5
- Scientists have made significant progress in understanding the signals involved in regulating oral keratinocyte cell motility and proliferative capacity, offering new insights into potential pharmacological manipulation for regenerative medicine. (news-medical.net)
- Professor Kenji Izumi and his team examined the impact of growth supplements on oral keratinocyte behavior. (news-medical.net)
- Interestingly, the study also revealed that the STAT3 and ERK1/2 pathways, previously thought to be major contributors to oral keratinocyte behavior, showed only minor effects. (news-medical.net)
- Furthermore, these findings contribute to the understanding of oral keratinocyte behavior and pave the way for future investigations into the complex interplay between different signaling pathways in oral keratinocytes. (news-medical.net)
- OKM consists of 500 ml of basal medium, 5 ml of oral keratinocyte growth supplement (OKGS, Cat. (sciencellonline.com)
Promote keratinocyte1
- Since keratinocyte differentiation inhibits keratinocyte proliferation, factors that promote keratinocyte proliferation should be considered as preventing differentiation. (wikipedia.org)
Gingival Keratinocytes3
- Primary gingival keratinocytes were isolated from the jaw and have important applications in antibiotic treatment, dental implants, and many other applications for oral biology research. (atcc.org)
- To download a certificate of analysis for Primary Gingival Keratinocytes ( PCS-200-014 ), enter the lot number exactly as it appears on your product label or packing slip. (atcc.org)
- The certificate of analysis for that lot of Primary Gingival Keratinocytes ( PCS-200-014 ) is not currently available online. (atcc.org)
Keratin and undergo1
- Keratinization is part of the physical barrier formation (cornification), in which the keratinocytes produce more and more keratin and undergo terminal differentiation. (wikipedia.org)
Apoptotic3
- Is disturbed clearance of apoptotic keratinocytes responsible for UVB-induced inflammatory skin lesions in systemic lupus erythematosus? (unboundmedicine.com)
- Inflammatory lesions in these patients were localised near accumulations of apoptotic keratinocytes similar as was seen in the majority of LE skin lesions. (unboundmedicine.com)
- We concluded that rosemary oil at a concentration of 1.25% may help the organism to inhibit excessive cell proliferation in tissues covered with keratinocytes, which may contribute to a healthy digestive system by stopping excessive cell proliferation and may be utilized in both animal feed and human nutrition, via the apoptotic pathway. (tubitak.gov.tr)
Stratified squamous2
- The predominant cell type in the epidermis is keratinocytes and they are located in the stratified squamous epithelia. (3hbiomedical.com)
- The epidermis is a stratified, squamous epithelium that consists primarily of keratinocytes in progressive stages of differentiation from deeper to more superficial layers. (medscape.com)
Epidermis3
- Keratinocytes are the primary type of cell found in the epidermis, the outermost layer of the skin. (wikipedia.org)
- Progenitors of keratinocytes reside and divide in the basal layer of the epidermis. (3hbiomedical.com)
- We have characterized an unusual cell phenotype in third passage cultures of a human keratinocyte strain derived from newborn foreskin epidermis. (rupress.org)
Epithelial4
- Oral keratinocytes, which play a crucial role in the formation of the oral mucosa epithelial cell sheet, have long been enigmatic in terms of their signaling regulation. (news-medical.net)
- This is because oral mucosa epithelial cell sheets (oral keratinocytes) have been clinically applied to treat diseases and reconstruct tissue defects in cornea, esophagus and urethra. (news-medical.net)
- This breakthrough research opens up new avenues for the efficient isolation, expansion, and sheet formation of cultured oral keratinocytes, which are essential for the successful clinical translation of epithelial cell sheets. (news-medical.net)
- We show here that the epithelial fusions observed in RIPK4 full knockout (KO) mice are E-cadherin dependent, as keratinocyte-specific deletion of E-cadherin in RIPK4 full KO mice rescued the tail-to-body fusion and fusion of oral epithelia. (ugent.be)
Cytokines1
- Apart from their protective functions, keratinocytes express adhesion molecules and cytokines, further suggesting an implication in skin innate immunity, tissue homeostasis, wound healing, cancer development, and skin-based gene-therapy. (3hbiomedical.com)
Viable3
- Following the application Bcl-2 was efficiently overexpressed in almost all viable keratinocytes. (bioone.org)
- The results of the present study demonstrated that treatment with PF (25, 50, and 100 µM) significantly increased the percentage of viable keratinocytes after UV‑B exposure. (spandidos-publications.com)
- In contrast, mice with keratinocyte-specific RIPK4 deletion during adult life remain viable. (ugent.be)
Differentiate1
- As keratinocytes divide and differentiate, they move from this deeper layer to the more superficial layers. (medscape.com)
Transfection1
- Optimized growth media, a keratinocyte-specific transfection kit, and other cell biology products support the growth and study of keratinocytes. (cellapplications.com)
Protein2
- Keratinocytes are named after keratin, which is the most abundant protein in this cell. (3hbiomedical.com)
- Activation of keratinocyte protein kinase C zeta in psoriasis plaques. (umassmed.edu)
Inhibition1
- These results suggest that Bach1 inhibition protect against high dose of UVA irradiation induced damage in keratinocytes. (bath.ac.uk)
Immunohistochemical1
- A significant increase in IL8 expression was observed in the M2-M3 stages of the disease and immunohistochemical staining showed the source as keratinocytes, suggesting an important role for keratinocyte-derived IL8 in the pathogenesis of DD. (biomedcentral.com)
Normal3
- they formed desmosomes and expressed the keratin profile characteristic of normal keratinocytes in culture. (rupress.org)
- Learning of the molecular mechanisms of the pathological processes development in the normal human keratinocytes (NHK) are difficult. (mendeley.com)
- General Information Human Dermal Keratinocytes (cAP-0212) are isolated from normal human adult dermal tissue. (angioproteomie.com)
Growth1
- Primary Keratinocytes and 3D Keratinocyte Models help R&D departments publish and develop new treamtents for improper skin cell growth and differentiation. (cellapplications.com)
Cell7
- By activating the EGF/EGFR signaling pathway and downstream cascades, such as Src/PI3K/Akt/mTOR, it may be possible to enhance the motility and proliferative capacity of oral keratinocytes during ex vivo cell expansion. (news-medical.net)
- In conclusion, the present study reported that PF was able to attenuate UV‑B‑induced cell damage in human keratinocytes. (spandidos-publications.com)
- This study aims to investigate the action of rosemary oil on the immortalized keratinocyte cell line. (tubitak.gov.tr)
- Keratinocyte proliferation, differentiation, and programmed cell death are complex and carefully choreographed processes. (3hbiomedical.com)
- This single cell layer of keratinocytes is attached to the basement membrane via hemidesmosomes. (medscape.com)
- Dermabrasion versus microneedling in transplantation of autologous noncultured melanocyte-keratinocyte cell suspension in patients with vitiligo. (medscape.com)
- Little is known about molecular mecha- desmosomal glycoproteins, resulting in the nisms affecting mast cell and T lympho- loss of keratinocyte cell-cell adhesion [ 1 ]. (who.int)
Clinical1
- Results of the present study point to a strong stimulation of the innate immune response at the level of the keratinocytes throughout most of the clinical stages, and a delayed response of the adaptive immune reaction. (biomedcentral.com)
Cultures1
- Evidence of increased keratinocyte proliferation in air-liquid interface cultures of non-bullous congenital ichthyosiform erythroderma. (medicaljournals.se)
Undergo1
- An unusual strain of human keratinocytes which do not stratify or undergo terminal differentiation in culture. (rupress.org)
Gene Expression1
- Millimeter wave exposure could affect gene expression in human keratinocytes, which might be related to the intensity and the times of exposure. (nih.gov)
Effects3
- Although, most of these studies have focused on treatment of tumors, the effects and mechanism of action in keratinocytes are still poorly understood. (hindawi.com)
- Biological effects of SLURP-1 on human keratinocytes. (medlineplus.gov)
- Incubation of ascorbate-preloaded keratinocytes with phenol produced an electron paramagnetic resonance-detectable signal of ascorbate radicals, suggesting that redox-cycling of one-electron oxidation products of phenol , its phenoxyl radicals, is involved in the oxidative effects. (cdc.gov)
Activation1
- Treatment with PF markedly reduced the production of ROS, and inhibited the activation of p38 and p53 in human keratinocytes, thus suggesting that the ROS‑p38‑p53 pathway has a role in UV‑B‑induced skin damage. (spandidos-publications.com)
Skin1
- Human and Rat skin-derived Keratinocytes offer a protective barrier to damage from the outside environment, pathogens, UV radiation, and water loss. (cellapplications.com)
Migration1
- Peptide-induced keratinocyte migration was mediated by purinergic receptors and metalloproteases. (nature.com)