1,721,013 research outputs found
P161 VENOUS ENDOTHELIAL GROWTH FACTOR PRODUCTION BY CHONDROCYTES CULTURED IN MONOLAYER AND IN MICROMASS
No full textIL-17, IL-1β and TNF-α stimulate VEGF production by dedifferentiated chondrocytes
No full textAbstractObjectiveTo verify the involvement of proinflammatory cytokines IL-17, IL-1β and tumor necrosis factor α (TNF-α) in cartilage vascularization by stimulating the production of vascular endothelial growth factor (VEGF) by chondrocytes isolated from patients with osteoarthritis (OA), in comparison with patients with rheumatoid arthritis (RA) and patients with femoral or humeral neck fracture (FP).DesignChondrocytes isolated from patients with OA were maintained in monolayer culture for several passages. Chondrocyte dedifferentiation was monitored by the synthesis of cathepsin B by these cells. Chondrocytes freshly isolated at each subculture (subcultures 1–3) were stimulated with IL-17, IL-1β or TNF-α. Supernatants were collected, immunoassayed for the production of VEGF and cathepsin B and assayed as the source of VEGF on the VEGF sensible ECV304 cell line. The cells were used to quantify intracellular cathepsin B enzymatic activity.ResultsIn differentiated conditions IL-1β and TNF-α, but not IL-17, can inhibit the spontaneous secretion of VEGF by human OA, RA and FP chondrocytes, and IL-17 can restore the decrease in VEGF secretion caused by TNF-α. IL-17, together with IL-1β and TNF-α, can enhance VEGF secretion to various extents by dedifferentiated OA chondrocytes. This change in effect with respect to primary culture was observable for all cytokines at the beginning of dedifferentiation, when the production of VEGF by chondrocytes had dramatically fallen and the cathepsin B synthesis had increased. The amount of VEGF induced by cytokines on dedifferentiated chondrocytes never reached the amount of VEGF produced by differentiated chondrocytes. VEGF produced by chondrocytes stimulated the ECV304 cell line proliferation.ConclusionsThese results indicate that dedifferentiated OA chondrocytes secrete VEGF after stimulation with proinflammatory cytokines. This event may be responsible for neovascularization found in OA cartilage
Chondrocytes from osteoarthritis patients revert to their origin phenotype once grown onto a hyaluronan-based scaffold.
No full text
Chemochine detection by multiplex technology: preliminary assessment of serum profiles during ageing.
No full textMultiple simultaneous analysis of chemokines and cytokines: preliminary results on ZINCAGE human plasma samples.
No full textLong-term in vitro expansion of osteoarthritic human articular chondrocytes do not alter genetic stability: a microsatellite instability analysis.
No full textIn this study, we investigated genetic damage acquisition during in vitro culture of human osteoarthritic (OA) chondrocytes to evaluate their safety for use in regenerative medicine clinical applications. In particular, we have addressed the impact of long-term in vitro culture on simple sequence repeat stability, to evaluate the involvement of the mismatch repair system (MMR) in the accumulation of genetic damage. MMR, the main post-replicative correction pathway, has a fundamental role in maintaining genomic stability and can be monitored by assessing microsatellite instability (MSI). MMR activity has been reported to decrease with age not only in vivo, but also in vitro in relationship to culture passages. OA chondrocytes from seven donors were cultured corresponding to 13-29 population doublings. Aliquots of the cells were collected and analyzed for MSI at five DNA loci (CD4, VWA, FES, TPOX, and P53) and for MMR gene expression at each subculture. Genetic stability was confirmed throughout the culture period. MMR genes demonstrated a strong coordination at the transcriptional level among the different components; expression levels were very low, in accordance with the observed genetic stability. The reduced expression of MMR genes might underline no need for increasing DNA repair control in the culture conditions tested, in which no genetic damage was evidenced. These data argue for the safety of chondrocytes for cellular therapies and are encouraging for the potential use of in vitro expanded OA chondrocytes, supporting the extension of autologous cell therapy procedures to degenerative articular diseases
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