Résumé
BACKGROUND:Synovial mesenchymal stem cells have the ability of multilineage differentiation in vitro, which are expected to be seed cells for the treatment of cartilage defects in cartilage tissue engineering. Appropriate growth factors are critical for the chondrocyte differentiation of synovial mesenchymal stem cells. OBJECTIVE:To study the role of secreted factors by chondrocytes to induce chondrogenesis of synovial mesenchymal stem cells. METHODS:The synovial mesenchymal stem cells and chondrocytes were harvested from rat knee joints and cultured through the digestion method. The supernatant was col ected from chondrocytes, and centrifuged, filtered and cryopreserved. The third passage synovial mesenchymal stem cells centrifuged as pel ets were cultured in the chondrocyte supernatant for 21 days. And the cells morphology was examined and the type II col agen and aggrecan were detected through immunohistochemistry and RT-PCR. RESULTS AND CONCLUSION:The synovial mesenchymal stem cellpel ets cultured in the chondrocyte supernatant became cartilage-like tissue after 21 days. The type II col agen was detected positively in the matrix of synovial mesenchymal stem cellpel et immunohistochemical y. RT-PCR examination showed that the type II col agen and aggrecan expressed in the synovial mesenchymal stem cellpel et cultured in the chondrocyte supernatant. It suggested that synovial mesenchymal stem cellcould be induced to differentiate into chondrocytes depending on soluble factors secreted by chondrocytes.