生长因子对人髁突软骨细胞Ⅰ、Ⅱ、Ⅲ型前胶原基因表达的调控研究

目的：研究低血清培养条件下转化生长因子－β（ＴＧＦ－β），胰岛素生长因子－Ⅰ（ＩＧＦ－Ⅰ），碱性成纤维生长因子（ｂＦＧＦ）对人髁突软骨细胞Ⅰ，Ⅱ，Ⅲ型前胶原基因表达的调控作用。方法：采用体外细胞培养及ｍＲＮＡ狭缝杂交的方法。结果：ＩＧＦ－Ⅰ对３种前胶原的ｍＲＮＡ水平无显著影响。ｂＧＦＧ，ＴＧＦ－β均呈不同程度地抑制Ⅱ型胶原的基因表达，分别为对照组的０．３５２及０．６５８倍同时ＴＧＦ－β显著增加了Ⅰ

The Regulation Effects of Growth Factors on the Procollagen Gene Expressions of Human Mandibular Condylar Cartilage Cells

OBJECTIVE: At the early stage of osteoarthrosis (OA) and joint damage, the cartilage cells proliferation increases dramatically, but this repair process is finally replaced by the progressive destruction of the cartilage. The reason, in accordance to the latest research, is the abnormal phenotype of the involved cartilage cell. This result suggests that the regulation of cartilage cell phenotype may be an effective way in the treatment of OA and other cartilage destructive diseases. In this study, the effects of transforming growth factor-beta(TGF-beta), insulin-like growth factor-I (IGF-I) and basic fibroblast growth factor (bFGF) on collagen expression of human mandibular condylar cartilage cells was investigated. METHODS: Chondrocytes were isolated from human fetus by enzymatic method. The second passage of the cells was used in this study. They were cultured in DMEM medium supplemented with 20% newborn calf serum (NCS). After the cells reached confluence, the medium was replaced by DMEM containing 0.4% NCS. Then the cells were exposed to different growth factors including IGF-I (10 ng/ml), TGF-beta (5 ng/ml) and bFGF (50 ng/ml). The steady state mRNA levels of different samples were examined by slot-blot hybridization. The results were analysed by Student t test. RESULTS: IGF-I had the least effects on the mRNA levels of three kinds of procollagen (type I, type II and type III). On the other hand, bFGF and TGF-beta could inhibit the expression of type II collagen by 0.352 and 0.685 times comparing with the control groups separately. TGF-beta increased type I collagen expression. Besides, bFGF and TGF-beta also increased the value of type I collagen/type II collagen. None of the three kinds of growth factors had obvious effects on the expression of type III collagen. CONCLUSION: IGF-I can maintain the chondrocyte differentiated phenotype, while TGF-beta and bFGF have inhibitory effects.