Differential effects of the immunosuppressant FK-506 on human α2(I) collagen gene expression and transforming growth factor β signaling in normal and scleroderma fibroblasts
Differential effects of the immunosuppressant FK-506 on human α2(I) collagen gene expression and transforming growth factor β signaling in normal and scleroderma fibroblasts
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DOI：
10.1002/art.20934
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发表时间：
2005-04-01
影响因子：
--
通讯作者：
Tamaki, K
中科院分区：
文献类型：
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作者：
Asano, Y;Ihn, H;Tamaki, K
客观的。研究 FK-506 对正常和硬皮病成纤维细胞中人 α 2(I) 胶原基因表达和转化生长因子 β (TGF β) 信号传导的影响。方法。分别通过免疫印迹和Northern印迹分析I型前胶原蛋白和α2(I)胶原信使RNA (mRNA)的表达水平。通过瞬时转染测定测定α2(I)胶原基因和3TP-Lux的启动子活性。通过免疫沉淀评估 I 型 TGF β 受体与 FK-506 结合蛋白 12 (FKBP12) 之间的相互作用。结果。 FK-506 不影响 I 型前胶原蛋白或 α 2(I) 胶原 mRNA 的基础表达，但显着降低正常成纤维细胞中 TGF beta 1 诱导的 I 型前胶原蛋白和 α 2(I) 胶原 mRNA 的表达。 FK-506 的作用受到转录后调节，但不受转录调节。在硬皮病成纤维细胞中，FK-506 通过转录后调节（但不是转录调节）显着降低 I 型前胶原蛋白和 α 2(I) 胶原 mRNA 的表达。 FK-506 增加了 3TP-Lux 启动子的基础活性，但不影响正常成纤维细胞中 TGF beta 1 诱导的启动子活性。相反，FK-506 不影响硬皮病成纤维细胞中的基础活性或 TGF beta 1 诱导的 3TP-Lux 启动子活性。此外，FKBP12 保护 I 型 TGF β 受体免受 TGF β 型 II 型受体的配体依赖性激活，在硬皮病成纤维细胞中与 I 型 TGF β 受体组成型解离。结论。 FK-506 通过降低 mRNA 的稳定性来抑制 α 2(I) 胶原蛋白基因表达，而不表现出其对硬皮病成纤维细胞中 TGF β 信号传导的激活作用。
Objective. To investigate the effects of FK-506 on the expression of the human alpha 2(I) collagen gene and transforming growth factor beta (TGF beta) signaling in normal and scleroderma fibroblasts.Methods. The expression levels of type I procollagen protein and alpha 2(I) collagen messenger RNA (mRNA) were analyzed by immunoblotting and Northern blotting, respectively. The promoter activities of alpha 2(I) collagen gene and 3TP-Lux were determined by transient transfection assay. Interaction between TGF beta receptor type I and FK-506 binding protein 12 (FKBP12) was evaluated by immunoprecipitation.Results. FK-506 did not affect the basal expression of type I procollagen protein or alpha 2(I) collagen mRNA, but it significantly reduced the TGF beta 1-induced expression of type I procollagen protein and alpha 2(I) collagen mRNA in normal fibroblasts. The effect of FK-506 was regulated posttranscriptionally, but not transcriptionally. In scleroderma fibroblasts, FK-506 significantly reduced the expression of type I procollagen protein and alpha 2(I) collagen mRNA through posttranscriptional regulation, but not transcriptional regulation. FK-506 increased the basal activity of the 3TP-Lux promoter, but it did not affect the TGF beta 1-induced promoter activity in normal fibroblasts. In contrast, FK-506 did not affect the basal or the TGF beta 1-induced 3TP-Lux promoter activity in scleroderma fibroblasts. Furthermore, FKBP12, which protects TGF beta receptor type I from ligand-independent activation by TGF beta receptor type II, constitutively dissociated from TGF beta receptor type I in scleroderma fibroblasts.Conclusion. FK-506 inhibits alpha 2(I) collagen gene expression by reducing the stability of mRNA without exhibiting its activation effect on TGF beta signaling in scleroderma fibroblasts.