Abstract: Objective To explore the effect of JNK inhibitor(SP600125)on the synthesis of extracellular matrix of chondrocytes.Methods Rabbit ear chondrocytes were obtained and cultured,and the effect of SP600125 on cell proliferation was determined by CCK-8 method.Rabbit ear chondrocytes were inoculated into PGA/PLA scaffolds,and cell-scaffold complexes were constructed and randomly divided into 2 groups:experimental group and control group.In the experimental group,the cell-scaffold complex was cultured in DMEM containing 10%FBS and SP600125,and the control group was cultured in DMEM containing 10%FBS only.After 8 weeks of in vitro culture,the expression of cartilage-specific genes such as IGF,COLⅡ,COLⅣand TGF-β1 was detected by RT-PCR,and HE staining and Safranin-O staining were performed.Results Compared with control group,the proliferation of chondrocytes in the experimental group was significantly promoted detected by CCK-8.After 8 weeks of in vitro culture,the expression of cartilage-specific genes IGF,COLⅡ,COLⅣand TGF-β1 in the experimental group was significantly lower than that in the control group(P<0.05).Histological observation showed that compared with the control group,the experimental group had a low degree of maturity and a decrease in extracellular matrix secretion.Conclusion SP600125 can reduce the synthesis of extracellular matrix of cartilage.

Key words: Osteoarthritis, Cartilage regeneration, Tissue engineering