Abstract: In this study,the role of resveratrol on dedifferentiation of rat chondrocyte and its possible mechanism were investigated.Cartilage cells was harvested under sterile conditions from normal rabbit′s joint of 4 weeks old rabbit and was then identified.The experiment were randomly divided into five groups:control group,0 μmol/L Resv group,2.5 μmol/L Resv group,5 μmol/L Resv group and 10 μmol/L group.The rabbit articular chondrocytes were subcultured in vitro to the 5th generation (named P1-P5).Inverted microscope was used to observe cell morphology at 1,3 and 5 generation respectively.The results indicated that the morphology at passage 1 chondrocytes were similar.The morphology of 2.5 μmol/L Resv group at passage 3 and 5 were nearly the same with passage 1,but other groups became enlarged,cytoplasmic stained light and the nucleus were not obvious;Alcian Blue staining was used to observe the changes of Proteoglycans.The results of Alcian Blue staining showed that the poly polysaccharide protein expression of 2.5 μmol/L Resv group were higher than other groups; β-galactosidase staining were used to identify the ageing cells.The results showed that the number of aging cells of 2.5 μmol/L Resv group was lower than other groups.RT-PCR were adopted to detect the RNA expression level of Aggrecan gene,SIRT1 gene,p53 gene,p21gene and P16 gene.RT-PCR analysis showed that SIRT1 gene of2.5 μmol/L Resv was significantly upregulated,and P53,P21 and P16 gene was downregulated.In conclusion,this experiment showed that 2.5 μmol/L Resv can inhibit the dedifferentiation of chondrocytes via upregulating expression of SIRT1 gene and downregulating expression of P53,P21 and P16.

Key words: resveratrol, chondrocyte, SIRT1, aging, dedifferentiation