| Summary: | 碩士 === 高雄醫學大學 === 生理及分子醫學研究所 === 97 === Recent years, it has already become a critical topic in the developed country that the articular cartilage traumas result in the cartilage degeneration or osteoarthritis, especially in the population of old age and contingency. In Taiwan, osteoarthritis has occupies the seventh place of chronic disease in old man. Articular cartilage lacks the stem cells and the blood flow supplied, which do increased difficulty in the cartilage self-repairing from the body. At present, it still lacks effective treatment or medicine to heal the articular cartilage disease. Our goal is to use tissue engineering for treating and regenerating the articular cartilage defect. In the process of Chondrogenesis, the collagens are critical for modulating the chondrogenic differentiation of human mesenchymal stem cells. Discoidin Domain Receptors (DDRs), collagen receptor, regulate several cell behaviors, including cells adhesion and cell differentiations. However, the roles of DDRs in chondrogenesis of mesenchymal stem cells remain undefined. Pellet cultures with chondro-induction medium were used for inducing chondrogenesis of hMSCs, Effect of DDRs on chondrogenesis of human adipose tissue derived mesenchymal stem cells (hADSCs) were confirmed by analyzing, the protein expression (DDRs) with Western blot, the chondrogenetic gene (SOX-9, Type II collagen & Aggrecan) expression with Real-time PCR, and sulfates glycosaminoglycans (sGAG) with Alcian blue stain and 1,9-dimethylmethylene blue assay. Chondro-induction (Ch-I) triggered increasing chondrogenetic gene and sGAG expression in hADSCs compare with control group. DDR1 gene expressions in Ch-I group shows significantly different from control group, and DDR1 protein expression was elevated after chondroinduction in early stage, while DDR2 gene expression and protein expression were not. We abrogated DDR1 gene expression with DDR1 short hairpin RNA (shRNA). The DDR1-depleted hADSCs was suppressed cell growth in Chondroinduction medium. The result not only showed that the expression of chondrogenic marker genes (SOX-9, Type II collagen & Aggrecan) in DDR1-depleted group were gradually increased compared to Mock group, but also sGAG synthesis was augmented in DDR1-depleted hADSCs. In conclusion, our findings show DDR1 play a negative control in the Chondrogenesis of hADSCs.
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