Signal transduction of TGF-b in rat articular chondrocytes

转化生长因子（TGF）-B促进软骨细胞的增殖和分化，并且假定其在软骨组织的修复中起作用。尽管已经克隆了TGF-β的I、II和III型受体，但TGF-β的信号转导机制仍不清楚。与其他细胞不同，TGF-β刺激软骨细胞中DNA的合成，表明TGF-β在软骨细胞中的信号转导不同于其他细胞。我们发现TGF-β可上调软骨细胞c-fos基因的表达，CAT法检测发现c-fos基因上游的TGF-β反应元件为-403 ~-222。本研究构建了大鼠关节软骨细胞c-DNA文库，并尝试用双杂交系统克隆TGF-β信号转导的中间蛋白。获得了几个菌落，目前正在筛选，但未获得阳性数据。需要进一步的研究来寻找新的蛋白质。

Transforming growth factor (TGF) -b promotes the proliferation and differentiation of chondrocytes, and it is assumed to play a role in the repair of cartilage tissue. The mechanism of signal transduction of TGF-b is still unknown, although type I,II and III receptors of TGF-b have been cloned. TGF-b stimulates the synthesis of DNA in chondrocytes unlike the other cells, suggesting signal transduction of TGF-b in chondrocytes is different from the others. We found that TGF-b upregulated the induction of c-fos gene in chondrocytes, and that TGF-b response element of upstream of c-fos gene is -403 to -222 using CAT assay. We have made c-DNA library of rat articular chondrocytes and tried to clone the protein intermediating the signal transduction of TGF-b by two hybrid system. Several colonies were obtained and they are screening now, however, no positive data are obtained. Further studies are needed to find a novel protein.