| Summary: | 碩士 === 臺北醫學大學 === 細胞及分子生物研究所 === 95 === Chondrocyte is the sole cell type of the cartilage. At the joint, cartilage covers the end of the bone. The extracellular matrix (ECM), a structure of highly hydrated matrix, is consisted of collagen, and glycosaminoglycan (GAG) which is made of hyauronic acid back bone with many other chondroitin sulfate, keratan sulfate and protein components. Chondrocytes are embedded in this ECM structure and produce new collagen and GAGs in cartilage. When chondrocytes are serially expanded, they progressively lose their original phenotype, this process typically described as dedifferentiation. According to previous studies in our laboratory, exogenous type II collagen promoted re-expression of type II collagen mRNA and GAG accumulation in near quiescent rabbit chondrocytes. In this study, we treat human chondrocytes with various exogenous extracellular matrix components (i.e. type II collagen, hyaluronic acid, or chondroitin sulfate). The results demonstrated that exogenous type II collagen indeed induced the re-expression of type II collagen and aggrecan mRNAs, and glycosaminoglycan (GAG) levels. Since exogenous type II collagen indeed make near quiescent chondrocytes re-differentiate, therefore, its preparations maybe be applied to osteoarthritis therapy in the future. In addition, integrins are the principal receptors on animal cells for the most of extracellular matrix proteins ― including collagens, fibronectin, and laminins. Consequently, this study also examined the related signal pathway of integrin. We found that the extracellular signal-regulared protein kinase (ERK) was activated during the induction of the differentiation of dedifferentiated chondrocytes.
|
|---|
