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目的 :探讨 TNF-α对胰岛素样生长因子 - 1(IGF- 1)激活人α1( )胶原启动子的作用。 方法 :构建含不同长短α1( )胶原启动子序列与氯霉素乙酰基转移酶 (CAT)报告基因的重组体 p COL H1 0 .2 7,p COL H1 2 .5 ;用脂质体法瞬时转染至NIH3T3细胞和人皮肤成纤维细胞中 ,加入 IGF- 1或 (和 ) TNF-α,测定 CAT活性。 结果 :10 0 ng/ m l IGF- 1可使转染至NIH3T3细胞的 p COL H1 0 .2 7和 p COL H1 2 .5表达的 CAT活性分别增高至对照的 (5 .4± 0 .2 5 )倍与 (5 .8± 0 .3)倍 ,使转染至人皮肤成纤维细胞的这两个重组体表达的活性分别增高至对照的 (4 .5± 0 .2 2 )倍与 (4 .9± 0 .2 )倍。而 TNF-α能抑制 IGF- 1诱导的 p COL H1 2 .5活性。 结论 :TNF- α在转录启动水平抑制 IGF- 1对人 α1( )胶原基因表达的促进作用。
Objective: To investigate the effect of TNF-α on human α1 (superscript +) collagen promoter activated by insulin-like growth factor-1 (IGF-1). Methods: Recombinant p COL H1 0. 27, p COL H1 2 .5 containing different lengths of α1 () collagen promoter and chloramphenicol acetyltransferase (CAT) reporter gene was constructed. Transfected into NIH3T3 cells and human dermal fibroblasts, the activity of CAT was measured by adding IGF-1 or (and) TNF-α. Results: The 10-ng / ml IGF-1 increased the CAT activity of pGLH1.27 and p-COL-H1-2.5 transfected to NIH3T3 cells to (4.5 ± 0.55 ) Times and (5 .8 ± 0. 3) -fold, respectively, increased the expressed activity of these two recombinants transfected into human dermal fibroblasts to (4.5 ± 0.222) times and ( 4 .9 ± 0 .2) times. While TNF-α inhibits IGF-1-induced p COL H1 2 .5 activity. CONCLUSION: TNF-α inhibits the promotion of human α1 () collagen gene expression at the transcription initiation level by IGF-1.