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*  Chondrogenic differentiation potential of osteoarthritic chondrocytes and their possible use in matrix-associated autologous...
In order to be able to use second-generation ACT techniques for the repair of cartilage defects in patients with OA, it is highly important to investigate whether OA chondrocytes have an irreversibly altered phenotype or if these cells can differentiate towards a hyaline cartilage phenotype after in vitro expansion. Today, there are conflicting data whether OA chondrocytes fulfill the prerequisites for ACT treatment or not [12, 13, 15, 21]. This encouraged us to investigate more thoroughly the chondrogenic differentiation potential of human OA chondrocytes using microarray technology in order to determine whether OA chondrocytes might possibly be used in second-generation ACT.. Microarray analysis of human OA and ND chondrocytes cultured in ML indicated that the OA chondrocytes were in a less differentiated state compared with the ND chondrocytes. This is thus in accordance with the ...
https://arthritis-research.biomedcentral.com/articles/10.1186/ar2800
*  Evaluation of CD98 Expression in Normal and Osteoarthritic Human Articular Chondrocytes
Background: Recent studies have provided evidence that integrins play roles in recognition of mechanical stimuli and its translation into a cellular response. Integrin signaling may be regulated by a number of mechanisms including accessory proteins such as CD98 (4F2 antigen). Objectives: To determine CD98 expression by human articular chondrocytes and its involvement in human articular mechanotransduction. Methods: CD98 expression was assessed by immunostaining of cryostat sections of snap frozen articular cartilage and in cultured cells by western blotting. Chondrocytes enzymatically isolated from macroscopically normal and osteoarthritic (OA) articular cartilage were grown in short term, primary monolayer culture and used in a resting state or following mechanical stimulation at 0.33Hz. Results: Human articular chondrocytes express CD98 and immunoreactivity revealed a similar heterogeneous pattern of CD98 in both normal and osteoarthritic (OA) human ...
http://iji.sums.ac.ir/article_16986.html
*  Human articular chondrocytes produce IL-7 and respond to IL-7 with increased production of matrix metalloproteinase-13 |...
Although IL-7 has traditionally been thought of as a T-cell regulatory cytokine, in this report the ability of human articular chondrocytes to produce IL-7, express an IL-7 receptor, and respond to IL-7 stimulation was demonstrated. Chondrocyte production of IL-7 was stimulated by catabolic and proinflammatory mediators, including the 110 kDa fibronectin fragment, and by the combined actions of IL-1β and IL-6. The stimulation of chondrocyte IL-7 production by fibronectin fragments appeared to be part of an autocrine loop mediated by the fragment stimulation of IL-1 and IL-6 production, because inhibition of these cytokines blocked fragment stimulated IL-7 production. IL-7 stimulated chondrocytes to produce MMP-13, a metalloproteinase that is responsible for degradation of type II collagen in cartilage, and caused proteoglycan release from cartilage explants. Additionally, increased production of IL-7 was measured in cultures of osteoarthritic chondrocytes ...
https://arthritis-research.biomedcentral.com/articles/10.1186/ar2376
*  The PI3K pathway regulates endochondral bone growth through control of hypertrophic chondrocyte differentiation | BMC...
The PI3K pathway has been shown to affect numerous cellular processes in a tissue-specific fashion; for example, it is required for survival in different cell types such as cardiomyocytes [34], cellular differentiation in the case of osteoclasts and keratinocytes [35, 36], and proliferation and differentiation of osteoblasts [35]. It also stimulates differentiation of CD4+ T-cells [37] and development and proliferation of B cells [38, 39]. We hypothesized that the PI3K pathway has similar effects in the growth plate, promoting endochondral bone growth by increasing proliferation and differentiation of chondrocytes and by suppressing apoptosis.. We found that inhibition of PI3K with LY294002 results in decreased differentiation, in both primary chondrocytes (micromass cultures) and organ cultures. Markers of both early chondrocyte differentiation such as collagen II and glycosaminoglycans and of late hypertrophic differentiation such as collagen X, p57, Alkaline phosphatase ...
https://bmcdevbiol.biomedcentral.com/articles/10.1186/1471-213X-8-40
*  HKU Scholars Hub: Kinesin-1 is involved in chondrocytes adhesion to extracellular matrix and motility
Intercalation movement of proliferative chondrocytes is crucial for their columnar organization which is essential for proper function of growth plate cartilage. The conventional motor protein kinesin‐1 directionally transporting various cargos along microtubules might be involved in this polarized cell movement. Kinesin‐1 is suggested to transport unknown cargo(s) modulating focal adhesion (FA) turnover which is a key step in cell movement. To investigate kinesin‐1's role in chondrocytes intercalation, we generate kinesin‐1 heavy chain (Kif5b) knockout mouse. In the growth plate of KIF5B deficient mouse, we observed abnormal cell morphology and disrupted columnar structure. Isolated mutant chondrocytes show reduced motility and adhesion ability to ECM proteins. Vinculin, the key regulator of focal adhesions, is found as a potential protein associated with KIF5B in mouse chondrocytes. Further study will investigate whether KIF5B affects ...
http://hub.hku.hk/handle/10722/189754
*  Effect of freezing on rabbit cultured chondrocytes
FILGUEIRAS, R.R et al. Effect of freezing on rabbit cultured chondrocytes. Arq. Bras. Med. Vet. Zootec. [online]. 2011, vol.63, n.1, pp.46-55. ISSN 1678-4162. http://dx.doi.org/10.1590/S0102-09352011000100008.. This work evaluated the effect of freezing on chondrocytes maintained in culture, aiming the establishment of a cell bank for future application as heterologous implant. Chondrocytes extracted from joint cartilage of nine healthy New Zealand White rabbits were cultivated and frozen with the cryoprotector 5% dimethylsulfoxide for six months. Phenotypic and scanning electron microscopy analyses were carried out to identify morphological and functional differences between fresh and thawed cells. After enzymatic digestion, a total of 4.8x105cells per rabbit were obtained. Fresh chondrocytes showed a high mitotic rate and abundant matrix was present up to 60 days of culture. Loss of phenotypic stability was notable in the thawed ...
http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0102-09352011000100008&lng=en&nrm=iso&tlng=en
*  Indian hedgehog signals independently of PTHrP to promote chondrocyte hypertrophy | Development
During longitudinal development of the long bone cartilage, periarticular chondrocyte differentiation, which adds cells to the columnar region, is followed by chondrocyte hypertrophy, which reduces cells in the columnar region. Therefore, the length of the columnar chondrocyte region is determined by three parameters: the pace of periarticular chondrocyte differentiation, the pace of chondrocyte hypertrophy and the rate of columnar chondrocyte proliferation (Fig. 7). As upregulated Ihh signaling promotes periarticular chondrocyte differentiation and increases the rate of columnar chondrocyte proliferation (Kobayashi et al., 2005b), the proliferating columnar chondrocyte region would be increased if chondrocyte hypertrophy were not altered. Our observation that the columnar chondrocyte region was shorter in the PTHrP-/-;Ptch1c/-; Col2a1-Cre double mutant than in the PTHrP-/- single mutant (Fig. 2B, Fig. 3A) demonstrates that Hh signaling also acts to promote chondrocyte hypertrophy in the absence ...
http://dev.biologists.org/content/135/11/1947
*  Synergistic chondroprotective effects of curcumin and resveratrol in human articular chondrocytes: inhibition of IL-1beta...
INTRODUCTION: Currently available treatments for osteoarthritis (OA) are restricted to nonsteroidal anti-inflammatory drugs, which exhibit numerous side effects and are only temporarily effective. Thus novel, safe and more efficacious anti-inflammatory agents are needed for OA. Naturally occurring polyphenolic compounds, such as curcumin and resveratrol, are potent agents for modulating inflammation. Both compounds mediate their effects by targeting the NF-kappaB signalling pathway. METHODS: We have recently demonstrated that in chondrocytes resveratrol modulates the NF-kappaB pathway by inhibiting the proteasome, while curcumin modulates the activation of NF-kappaB by inhibiting upstream kinases (Akt). However, the combinational effects of these compounds in chondrocytes has not been studied and/or compared with their individual effects. The aim of this study was to investigate the potential synergistic effects of curcumin and resveratrol on IL-1beta-stimulated human ...
http://epubs.surrey.ac.uk/808686/
*  Reactive oxygen species induce chondrocyte hypertrophy in endochondral ossification | JEM
Chondrogenesis occurs via three steps: (a) commitment to chondrocyte differentiation by mesenchymal cells, seen as mesenchymal condensation; (b) chondrocyte proliferation in the growth plate to facilitate longitudinal development; and (c) differentiation of proliferating chondrocytes to hypertrophic chondrocytes (for review see references 1, 2). During endochondral ossification, chondrocyte hypertrophy is critical, because cells alter the extracellular matrix and induce vascular invasion. Extrinsic factors such as bone morphogenetic proteins, Indian hedgehog, and modulators such as Sox9, Runx2, Smads, and histone deacetylase 4 are reportedly essential for chondrogenesis (1, 2). Loss of histone deacetylase 4 causes early onset of hypertrophy, followed by growth retardation (6). Overexpression of Runx2 under the control of a type II collagen promoter/enhancer induces dwarfism because of precocious endochondral ossification and accelerated chondrocyte differentiation (4, 5). ...
http://jem.rupress.org/content/204/7/1613
*  Ultrasound stimulates proteoglycan synthesis in bovine primary chondrocytes.
Mechanical forces can stimulate the production of extracellular matrix molecules. We tested the efficacy of ultrasound to increase proteoglycan synthesis in bovine primary chondrocytes. The ultrasound-induced temperature rise was measured and its contribution to the synthesis was investigated using bare heat stimulus. Chondrocytes from five cellular isolations were exposed in triplicate to ultrasound (1 MHz, duty cycle 20%, pulse repetition frequency 1 kHz) at average intensity of 580 mW/cm2 for 10 minutes daily for 1-5 days. Temperature evolution was recorded during the sonication and corresponding temperature history was created using a controllable water bath. This exposure profile was used in 10-minute-long heat treatments of chondrocytes. Heat shock protein 70 (Hsp70) levels after one-time treatment to ultrasound and heat was analyzed by Western blotting, and proteoglycan synthesis was evaluated by 35S-sulfate incorporation. Ultrasound treatment did not ...
http://umu.diva-portal.org/smash/record.jsf?pid=diva2:843205
*  "A Morphological Assessment of Bovine Chondrocytes Cultured on Poly(Eth" by R. M. Sawtell, M. V. Kayser et al.
A heterocyclic methacrylate polymer system, PEMA/THFMA, has shown potential as a biomaterial for cartilage repair in a rabbit model and has properties making it suitable for use clinically. The ability of the polymer system, PEMA/THFMA, and a related system, PEMA/HEMA, to support chondrocytes in vitro was assessed by scanning electron microscopy. Chondrocytes adhered to the surface of the PEMA/THFMA by day one, having a rounded morphology and clustered appearance opposed to the Thermanox® control, where the cells had spread out and become fibroblastic in appearance. The chondrocytes divided rapidly on the PEMA/ THFMA system by day three and had completely covered the surface by day seven. In contrast, chondrocytes did not adhere well to the more hydrophilic PEMA/ HEMA system. A few cells were seen on the surface by day one and by days three and seven, there was no evidence of cell growth or spreading across the surface. In conclusion, the ...
http://digitalcommons.usu.edu/cellsandmaterials/vol5/iss1/6/
*  Chondrocytes, Autologous Cultured (Implantation Route) Description and Brand Names - Mayo Clinic
Autologous cultured chondrocytes are used, as part of an overall program that includes knee surgery and special exercises, to help repair damaged knee cartilage. Cartilage is a type of tissue that joins together and helps support parts of the body. Autologous cultured chondrocytes are the patient's own cartilage cells. The cells are removed from the patient and sent to a laboratory, where they are processed to increase their number. The cells are then implanted (placed) in the damaged part of the knee. After implantation, the chondrocytes help form new, healthy cartilage. ...
http://www.mayoclinic.org/drugs-supplements/chondrocytes-autologous-cultured-implantation-route/description/drg-20062805?DSECTION=all
*  The Quest for Height: Grow Taller | Increase Height | Bone Size: MSCs versus chondrocyte gene expression
This preliminary study aims to determine the differentially expressed proteins from chondrogenic differentiated multipotent stromal cells (cMSCs) in comparison to undifferentiated multipotent stromal cells (MSCs) and adult chondrocytes (ACs). Methods: ACs and bone marrow-derived MSCs were harvested from New Zealand White rabbits (n = 3). ACs and cMSCs were embedded in alginate and were cultured using a defined chondrogenic medium containing transforming growth factor-beta 3 (TGF-β3). Chondrogenic expression was determined using type-II collagen, Safranin-O staining and glycosaminoglycan analyses. Two-dimensional gel electrophoresis (2-DE) was used to isolate proteins from MSCs, cMSCs and ACs before being identified using liquid chromatography-mass spectrometry (LC-MS). The differentially expressed proteins were then analyzed using image analysis software. Results: Both cMSCs and ACs were positively stained with type-II collagen and safranin-O. The expression of glycosaminoglycan in cMSCs was ...
http://www.heightquest.com/2012/02/mscs-versus-chondrocyte-gene-expression.html
*  British Library EThOS: The effects of mechanical stimulation and cytokine stimulation on proteoglycan levels in human...
Transformed chondrocyte cell lines and primary OA human articular chondrocytes (HAC) were grown in monolayer culture. Cells were exposed to cyclical mechanical stimulation (MS) using an apparatus that produces strain on the base of the culture dish, causing the deformation of attached cells. Chondrocytes were also incubated with a cytokine cocktail containing IL-1β, TNFα, IL-6 and IFNγ (CYT). The transformed chondrocyte cell lines C20A4 and C2812 did not express detectable levels of NOS protein or nitrite activity. However increased inducible NOS (iNOS) mRNA following CYT stimulation suggested that the cells were able to sense the CYT stimulation. Primary OA HAC showed increased production of iNOS mRNA, protein and nitrite following CYT or IL-1β stimulation. The simultaneous application of CYT and MS also showed elevated iNOS mRNA, protein and nitrite levels, although these were significantly lower than following CYT alone. An IL-4 neutralising antibody and a β1 integrin ...
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.653045
*  All Faculty | Duke Mechanical Engineering and Materials Science
The mechanical environment of the chondrocyte is an important factor that influences the maintenance of the articular cartilage extracellular matrix. Previous studies have utilized theoretical models of chondrocytes within articular cartilage to predict the stress-strain and fluid flow environments around the cell, but little is currently known regarding the cellular properties which are required for implementation of these models. The objectives of this study were to characterize the mechanical behavior of primary human chondrocytes and to determine the Young's modulus of chondrocytes from non-osteoarthritic ('normal') and osteoarthritic cartilage. A second goal was to quantify changes in the volume of isolated chondrocytes in response to mechanical deformation. The micropipette aspiration technique was used to measure the deformation of a single chondrocyte into a glass micropipette in response to a prescribed pressure. The results of this ...
http://fds.duke.edu/db/pratt/mems/faculty/guilak/publications/106815
*  All Faculty | Duke Mechanical Engineering and Materials Science
The mechanical environment of the chondrocyte is an important factor that influences the maintenance of the articular cartilage extracellular matrix. Previous studies have utilized theoretical models of chondrocytes within articular cartilage to predict the stress-strain and fluid flow environments around the cell, but little is currently known regarding the cellular properties which are required for implementation of these models. The objectives of this study were to characterize the mechanical behavior of primary human chondrocytes and to determine the Young's modulus of chondrocytes from non-osteoarthritic (`normal') and osteoarthritic cartilage. A second goal was to quantify changes in the volume of isolated chondrocytes in response to mechanical deformation. The micropigette aspiration technique was used to measure the deformation of a single chondrocyte into a glass micropipette in response to a prescribed pressure. The results of this ...
http://fds.duke.edu/db/pratt/mems/faculty/guilak/publications/64137
*  ZFIN Publication: Askary et al., 2015
An early event in skeletal joint development is the specification of articular chondrocytes at the joint surface. Articular chondrocytes are distinct in producing lower levels of cartilage matrix and not being replaced by bone, yet how they acquire these properties remains poorly understood. Here, we show that two members of the Iroquois transcriptional repressor family, Irx7 and Irx5a, function to block chondrocyte maturation at the developing hyoid joint of zebrafish. These Irx factors suppress the production of cartilage matrix at the joint in part by preventing the activation of a col2a1a enhancer by Sox9a. Further, both zebrafish Irx7 and mouse IRX1 are able to repress cartilage matrix production in a murine chondrogenic cell line. Iroquois proteins may therefore have a conserved role in keeping chondrocytes in an immature state, with the lower levels of cartilage matrix produced by these immature cells contributing to joint flexibility ...
http://zfin.org/ZDB-PUB-151112-6
*  Background Donor site morbidity, limited amounts of cells, lack of phenotype
... during extension, and age-related drop in chondrogenic activity present critical road blocks to the usage of autologous chondrocyte implantation for cartilage fix. neocartilage made by juvenile chondrocytes was 100-flip greater than WHI-P180 in neocartilage made by adult cells. Collagen type type and II IX mRNAs in clean juvenile chondrocytes had been 100- and 700-collapse higher, respectively, than in adult chondrocytes. The distributions of collagens II and IX had been similar in indigenous juvenile cartilage and in neocartilage created by juvenile cells. Juvenile cells grew considerably quicker in monolayer civilizations than adult cells (p = 0.002) and proteoglycan amounts stated in agarose lifestyle was significantly higher in juvenile cells than in adult cells after multiple passages (p < 0.001). Juvenile chondrocytes didn't stimulate lymphocyte proliferation. Conclusions These outcomes record a dramatic age group ...
http://researchhunt.com/2017/09/22/background-donor-site-morbidity-limited-amounts-of-cells-lack-of-phenotype/
*  The Regional Sensitivity of Chondrocyte Gene Expression to Coactive Mechanical Load and Exogenous TNF-α Stimuli | Journal of...
Both mechanical load and elevated levels of proinflammatory cytokines have been associated with the risk for developing osteoarthritis (OA), yet the potential interaction of these mechanical and biological factors is not well understood. The purpose of this study was to evaluate the response of chondrocytes to the effects of dynamic unconfined compression, TNF-α, and the simultaneous effects of dynamic unconfined compression and TNF-α. The response to these three treatments was markedly different and, taken together, the response in the gene expression of chondrocytes to the different treatment conditions suggest a complex interaction between structure, biology, and mechanical loading.. ...
http://biomechanical.asmedigitalcollection.asme.org/article.aspx?articleid=1886121&resultClick=1
*  Ca2+-sensitive phosphoinositide hydrolysis is activated in synovial cells but not in articular chondrocytes | Biochemical...
Cell-to-cell diffusion of second messengers across intercellular channels allows tissues to co-ordinate responses to extracellular stimuli. Intercellular diffusion of inositol 1,4,5-trisphosphate, locally produced by focal stimulations, sustains the propagation of intercellular Ca2+ waves, by stimulating the release of intracellular Ca2+ in neighbouring cells. We previously demonstrated that in cultured articular chondrocytes and HIG-82 synovial cells, studied with digitial fluorescence video imaging, mechanical stimulation of a single cell induced intercellular Ca2+ waves dependent on the presence of gap junctions. In the absence of extracellular Ca2+ the propagating distance of the wave decreased significantly in HIG-82 cells, but appeared unaffected in chondrocytes. We now show that both cells types express connexin 43 and a similar functional coupling, thus suggesting that the different Ca2+ sensitivity of intercellular waves is not due to major differences in gap ...
http://www.biochemj.org/content/344/2/545
*  Most recent papers with the keyword Sox9 | Read by QxMD
Autologous chondrocyte implantation (ACI) has emerged as a new approach to cartilage repair through the use of harvested chondrocytes. But the expansion of the chondrocytes from the donor tissue in vitro is restricted by limited cell numbers and dedifferentiation of chondrocytes. In this study, we used four types of hydrogels including agarose, alginate, Matrigel and collagen type I hydrogels to serve as cell substrates and investigated the effect on proliferation and phenotype maintenance of chondrocytes. As a substrate for monolayer culture, collagen facilitated cell expansion and effectively suppressed the dedifferentiation of chondrocytes, as evidenced by fluorescein diacetate / propidium iodide (FDA/PI), hematoxylin-eosin staining (HE), Safranin O, immunofluorescenceassay, biochemistry analysis and quantitative real-time polymerase chain reaction (qRT-PCR ...
https://www.readbyqxmd.com/keyword/46560
*  The effect of intra-articular pressure and mechanical load on articular chondrocyte cellular signalling
The various forms of joint loading have been found to differentially influence anatomical and molecular responses, which together are aimed to maintain the joint homeostasis. To elucidate these mechanisms of mechanotransduction, we review the roles of the distinct joint components, as well as numerous in vitro studies that have been performed to ... read more unravel chondrocyte responses in changing environments. The main signalling pathways in transduction of load signals are initiated by integrins sensing matrix deformation and by altered interstitial pH, influencing ion fluxes through membrane channels. Downstream signalling after static compression occurs mainly via the MAPK pathways of ERK1/2, SAPK (Jnk) and p38, which directly influence transcription factors of genes involved in cartilage breakdown. In contrast, cyclic compression and mild shear forces lead to membrane hyperpolarisation and subsequently stimulates cartilage matrix synthesis. These findings add further comprehension with ...
https://dspace.library.uu.nl/handle/1874/255225
*  IJMS | Free Full-Text | The COX-2 Selective Blocker Etodolac Inhibits TNFα-Induced Apoptosis in Isolated Rabbit Articular...
Chondrocyte apoptosis contributes to the disruption of cartilage integrity in osteoarthritis (OA). Recently, we reported that activation of volume-sensitive Cl− current (ICl,vol) mediates cell shrinkage, triggering apoptosis in rabbit articular chondrocytes. A cyclooxygenase (COX) blocker is frequently used for the treatment of OA. In the present study, we examined in vitro effects of selective blockers of COX on the TNFα-induced activation of ICl,vol in rabbit chondrocytes using the patch-clamp technique. Exposure of isolated chondrocytes to TNFα resulted in an obvious increase in membrane Cl− conductance. The TNFα-evoked Cl− current exhibited electrophysiological and pharmacological properties similar to those of ICl,vol. Pretreatment of cells with selective COX-2 blocker etodolac markedly inhibited ICl,vol activation by TNFα as well as subsequent apoptotic events such as apoptotic cell volume decrease (AVD) and elevation of caspase-3/7 activity. In ...
http://www.mdpi.com/1422-0067/14/10/19705/notes
*  Chondrogenesis in co-culture: An intensive interaction between mesenchymal stem cells and primary chondrocytes. - Surrey...
Csaki, C, Matis, U, Mobasheri, A, Putz, R, Ye, H and Shakibaei, M (2007) Chondrogenesis in co-culture: An intensive interaction between mesenchymal stem cells and primary chondrocytes. ...
http://epubs.surrey.ac.uk/827055/
*  Carticel (Autologous Cultured Chondrocytes for Implantation): Side Effects, Interactions, Warning, Dosage & Uses
Learn about Carticel (Autologous Cultured Chondrocytes for Implantation) may treat, uses, dosage, side effects, drug interactions, warnings, patient labeling, reviews, and related medications.
https://www.rxlist.com/carticel-drug.htm