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  • epithelium
  • The SSC niche is found in the seminiferous epithelium of mammalian testis, and is primarily constituted of Sertoli and peritubular myoid cells. (wikipedia.org)
  • bone
  • The vast majority of hematopoietic stem cells (HSCs) reside in specialized niches within the bone marrow during steady state, maintaining lifelong blood cell production. (biomedcentral.com)
  • In adults, osteoblasts, responsible for osteogenesis, and hematopoietic cells, responsible for hematopoiesis, are closely associated in the bone marrow, suggesting a reciprocal relationship between the two. (jci.org)
  • Sinusoidal endothelial cells in bone marrow have been revealed as an alternative HSC niche called the vascular niche. (jci.org)
  • In this Review we compare the architecture of these 2 HSC niches in bone marrow. (jci.org)
  • Hematopoiesis of bone cells and marrow stromal cells. (jci.org)
  • In the bone marrow HSCs reside either next to osteoblasts on the endosteal niche or adjacent to endothelial cells of sinusoidal vessels. (jci.org)
  • Upon each division, 1 daughter cell leaves the bone to proliferate and differentiate into various lineages. (jci.org)
  • HSCs and their progeny are surrounded by stromal cells derived from MSCs, which also reside in the bone cavity. (jci.org)
  • This niche relocates from the yolk sac to eventually rest in the bone marrow of mammals. (wikipedia.org)
  • In 1978, after observing that the prototypical colony-forming stem cells were less capable at replacing differentiated cells than bone marrow cells injected into irradiated animals, Schofield proposed that a specialized environment in the bone marrow allows these precursor cells to maintain their cellular reconstitution potential. (wikipedia.org)
  • Now researchers are reporting in the scientific journal EMBO that the bone marrow niche where HSC's form also ages, contributing to the problem. (eurekalert.org)
  • In a study published March 2, scientists from the University of Ulm in Germany and Cincinnati Children's Hospital Medical Center in the United States propose rejuvenating the bone marrow niche where HSCs are created. (eurekalert.org)
  • Conducting their study in mouse models, the scientists point to cells in the bone marrow called osteoblasts, which help form bone. (eurekalert.org)
  • We show that the place where HSCs form in the bone marrow loses osteopontin upon aging, but if you give back the missing protein to the blood-forming cells they suddenly rejuvenate and act younger," says Hartmut Geiger, PhD, study lead investigator at the Institute for Molecular Medicine and Aging Research Center at the University of Ulm , and the Division of Experimental Hematology and Cancer Biology at Cincinnati Children's. (eurekalert.org)
  • Another experiment monitored levels of osteopontin and other proteins linked to distinct cells in bone marrow during the aging process. (eurekalert.org)
  • Scientists followed up the earlier experiments by transplanting bone marrow cells from older mice (19-21 months) into young mice (8 to 10 weeks). (eurekalert.org)
  • Osteopontin levels are not only low in the bone marrow niche, but also in the blood upon aging. (eurekalert.org)
  • This interaction between Paneth cells and ISCs is mediated by expression in Paneth cells of bone stromal antigen 1 (Bst-1), an ectoenzyme that produces the paracrine factor cyclic ADP ribose (cADPR). (labome.org)
  • Detailed analysis of population dynamics within the bone marrow niche allows us to ascribe mechanisms to distinct disease outcomes and suggests experiments to distinguish between these mechanisms. (pnas.org)
  • In adult mammals the bone marrow is the site of hematopoiesis and contains the HSC niche. (pnas.org)
  • These include the cloning of a cDNA for parathyroid hormone, the identification of a role for parathyroid hormone-related protein in endochondral ossification through Indian hedgehog (IHH) activation, and studies that identified a role for parathyroid hormone in the regulation of the bone marrow stem cell niche. (wikipedia.org)
  • Although such attempts produced no positive benefit, further research found in the mid twentieth century that human cells could be used to help prevent the human body rejecting transplanted organs, leading in time to successful bone marrow transplantation. (wikipedia.org)
  • Bone marrow transplants have been found to be effective, along with some other kinds of human cell therapy - for example in treating damaged knee cartilage. (wikipedia.org)
  • Stem cells from the bone marrow, which is derived from mesoderm, can differentiate into liver, lung, GI tract and skin, which are derived from endoderm and mesoderm. (wikipedia.org)
  • progenitor cell
  • The CMP can then further differentiate into the megakaryocyte-erythroid progenitor cell (MEP), which goes on to make RBCs and platelets, or the granulocyte/macrophage progenitor (GMP), which gives rise to the granulocytes of the innate immune response. (wikipedia.org)
  • The hemangioblast theory, which posits that the RBCs and ECs derive from a common progenitor cell, was developed as researchers observed that receptor knockout mice, such as flk1-/-, exhibited defective RBC formation and vessel growth. (wikipedia.org)
  • HSCs
  • HSCs and their progeny are surrounded by stromal cells in BM (Figure 1 ). (jci.org)
  • Dexter observed that mesenchymal stromal cells could maintain early HSCs ex vivo, and both Lord and Gong showed that these cells localized to the endosteal margins in long bones. (wikipedia.org)
  • CINCINNATI - As people get older so do the hematopoietic stem cells (HSCs) that form their blood, creating an increased risk for compromised immunity and certain blood cancers. (eurekalert.org)
  • This could mean younger acting HSCs that form healthier blood cells, boosted immunity in older people, and a better defense mechanism against certain cancers, according to study authors. (eurekalert.org)
  • The authors also saw aged HSCs treated with recombinant osteopontin regain their youthful characteristics and capacity to form different blood-cell types. (eurekalert.org)
  • Upon intravenous transplantation, hematopoietic stem cells (HSCs) can home to specialized niches, yet most HSCs fail to engraft unless recipients are subjected to toxic preconditioning. (sciencemag.org)
  • We provide evidence that, aside from immune barriers, donor HSC engraftment is restricted by occupancy of appropriate niches by host HSCs. (sciencemag.org)
  • hair follicle
  • p. 1353 ) show that genetic activation of β-catenin within hair follicle stem cells generates axes of hair growth by coordinated cell divisions and cell movements, even when the normal niches-the dermal papillae-are laser-ablated. (sciencemag.org)
  • Using live imaging, we show that activation of β-catenin specifically within mouse hair follicle stem cells generates new hair growth through oriented cell divisions and cellular displacement. (sciencemag.org)
  • mammalian
  • The existence of niches has long been predicted from mammalian studies, but identifying stem. (biomedcentral.com)
  • Here we will explore the emerging effects of diet on nutrient-sensing pathways active in mammalian tissue stem cells and their relevance to normal and cancerous growth. (labome.org)
  • The SSC niche is found in the seminiferous epithelium of mammalian testis, and is primarily constituted of Sertoli and peritubular myoid cells. (wikipedia.org)
  • neurons
  • 6-8) It is well known that ECM nourishment can sequester and modulate stem cell niches along with synbiotic protein peptide formats to modulate stem cell niches and that afferent neurons can accomplish some astounding feats of regeneration and neurogenesis. (thefreelibrary.com)
  • 5,9-12) A default in ECM modulation occurs when microbial cells functioning as nutrient factories are depleted or when afferents neurons are desensitized by nonpolar lipids, denatured proteins, and the ionic stressors that are common in most water purification methods. (thefreelibrary.com)
  • When the neurons reach the OB they differentiate into GABAergic interneurons as they are integrated into either the granule cell layer or periglomerular layer. (wikipedia.org)
  • Under basal conditions, apoptotic corpses of newly generated neurons are rapidly phagocytosed from the niche by unactivated microglia in the adult SGZ. (wikipedia.org)
  • The brain comprises many different types of neurons, but the SGZ generates only one type: granule cells-the primary excitatory neurons in the dentate gyrus (DG)--which are thought to contribute to cognitive functions such as memory and learning. (wikipedia.org)
  • These processes act as a scaffold upon which newly formed neurons can migrate the short distance from the SGZ to the granule cell layer. (wikipedia.org)
  • Neuroblasts represent the last stage of precursor cell development before cells exit the cell cycle and assume their identity as neurons. (wikipedia.org)
  • At this point, after exiting the cell cycle, cells are considered immature neurons. (wikipedia.org)
  • The large majority of postmitotic neurons undergo apoptosis, or cell death. (wikipedia.org)
  • Eventually, the neurons are integrated into the hippocampal circuitry as fully matured granule cells. (wikipedia.org)
  • Multipotency or multidifferentiative potential, which is the ability to generate progeny of several distinct cell types, (for example glial cells and neurons) as opposed to unipotency, which is the term for cells that are restricted to producing a single-cell type. (wikipedia.org)
  • CSCs
  • Combined with its role in the protection of CSCs against genotoxic insults, these data strongly put forward the niche as an important target for novel therapies. (aacrjournals.org)
  • However, recent data suggest that tumor cancer stem cells (CSCs) in the stem-cell niches, with self-renewing capacities, might be responsible for tumor initiation, propagation, and recurrence. (hindawi.com)
  • therefore, employing the same logic used for developmental hierarchies, niches that maintain CSCs, should also exist (see refs. (aacrjournals.org)
  • At least two possibilities exist for generating CSC niches: either they are manufactured as nascent domains by tumor cells, or CSCs usurp existing tissue-specific stem cell niches. (aacrjournals.org)
  • Localization of nascent CSC niches is complicated because there are no common anatomical features among tumors ( Fig. 2 ), and consensus is continually shifting about the identity of CSCs. (aacrjournals.org)
  • Regeneration
  • Nourishment offers cheaper, quicker, and potentially better ways to augment stem cell regeneration. (thefreelibrary.com)
  • Wnt/β-catenin signaling is a key pathway that plays a conserved role in regulating stem cell function during adult tissue regeneration. (sciencemag.org)
  • β-Catenin activation is sufficient to induce hair growth independently of mesenchymal dermal papilla niche signals normally required for hair regeneration. (sciencemag.org)
  • This study demonstrates a mechanism by which Wnt/β-catenin signaling controls stem cell-dependent tissue growth non-cell autonomously and advances our understanding of the mechanisms that drive coordinated regeneration. (sciencemag.org)
  • Alternately, it was also reported that differentiated tubular epithelial cells are the driving mechanism for regeneration after injury, using proliferative expansion as the mechanism. (wikipedia.org)
  • maintain stem
  • Interactions will include shared reliance on nutrients, cofactors, and physiological conditions required to maintain stem cell properties. (pnas.org)
  • modulate
  • Both synthetic and natural biomaterials are reviewed with emphasis on how material-stem cell interactions direct specific signaling pathways and ultimately modulate the cell fate. (springer.com)
  • tumor
  • In line with this idea is the observation that only a small fraction of tumor cells is capable of initiating a new tumor. (aacrjournals.org)
  • The niche serves as a sort of safe harbor for the cancer stem cells, keeping them away from the site of the tumor and preserving their ability to regrow the tumor once it has been removed and the malignant areas of the brain have been treated. (ucla.edu)
  • Beating of the cilia of ependymal cells appears to set up concentration gradients of guidance molecules, such as cytokines TNF-α (tumor necrosis factor) and IGF-1 (insulin-like growth factor), to direct migration of neuroblasts, such as in the RMS. (wikipedia.org)
  • functional
  • To determine the molecular signals elaborated in this niche, we undertook a functional genomics approach that combines extensive sequence mining of a subtracted cDNA library, high-density array hybridization and in-depth bioinformatic analyses. (pnas.org)
  • The niche must have both anatomic and functional dimensions. (wikipedia.org)
  • interactions
  • Several factors are important to regulate stem-cell characteristics within the niche: cell-cell interactions between stem cells, as well as interactions between stem cells and neighbouring differentiated cells, interactions between stem cells and adhesion molecules, extracellular matrix components, the oxygen tension, growth factors, cytokines, and the physicochemical nature of the environment including the pH, ionic strength (e.g. (wikipedia.org)
  • Due to their role in maintaining stem cell activity, disrupting CSC-niche interactions may be crucial for overcoming barriers to therapeutic resistance. (aacrjournals.org)
  • This is a particularly helpful perspective if interactions between healthy and diseased cell types can affect the disease progression, as is now widely believed. (pnas.org)
  • Ruth Chiquet-Ehrismann (9 November 1954 - 4 September 2015) was a Swiss biochemist and cell biologist working on interactions in the extracellular matrix. (wikipedia.org)
  • lineages
  • Injection of MKPC into mice post-ischemic injury saw the MKPC regenerating different cell lineages and was able to regenerate renal function and enhanced survival. (wikipedia.org)
  • neurogenic
  • Unique to the adult SVZ, ependymal cells lining the ventricular wall are in close association with neural precursors and their progeny, acting like a shield to protect the "neurogenic niche", a zone in which stem cells are retained after embryonic development for the production of new cells of the nervous system. (wikipedia.org)
  • Signaling
  • We have recently demonstrated that CR in young mice augments ISC function by reducing mechanistic target of rapamycin complex 1 (mTORC1) signaling in Paneth cells, and that these effects of CR can be mimicked by rapamycin (an mTORC1 inhibitor). (labome.org)
  • Specifically, we will test the hypotheses that induction of niche Bst-1 by CR and rapamycin boosts ISC function in old mice (Aim 1);that the transcription factor PPAR-gamma mediates this response in Paneth cells (Aim 2);and that cADPR-activated signaling mediates this response in ISCs (Aim 3). (labome.org)
  • Activated β-catenin enhances Wnt ligand secretion, and these ligands can then activate Wnt signaling in adjacent cells that do not have activated β-catenin, indicating how activated stem cells could influence neighboring cells during normal growth and in cancer. (sciencemag.org)
  • Wild-type cells are co-opted into new hair growths by β-catenin mutant cells, which non-cell autonomously activate Wnt signaling within the neighboring wild-type cells via Wnt ligands. (sciencemag.org)
  • CE stem cells were co-cultured in the presence of different CE cells/retinal cells/hematopoietic cells in the presence and absence of perturbed Notch/Wnt/c-kit signaling to examine the effects of different environments (and underlying mechanisms) on stem cell properties and potential. (arvojournals.org)
  • Tenascin-C is required for normal Wnt/b-catenin signaling in the whisker follicle stem cell niche. (wikipedia.org)