大鼠肝纤维化形成过程中TGF-β1/ERK信号通路与Ⅰ、Ⅲ、Ⅳ型胶原表达变化

The changes of TGF-β1/ERK signaling pathway and typeⅠ,Ⅲ,Ⅳ collagen in the process of hepatic fibrosis formation

目的观察大鼠肝纤维化（hepatic fibrosis,HF）形成过程中TGF-β1/ERK信号通路蛋白与Ⅰ、Ⅲ、Ⅳ型胶原蛋白表达的变化。方法 SD大鼠采用CCl4复合因素制备HF模型,分别于第2、3.5、4.5、5、6、10周时,取肝组织采用Masson染色检测肝细胞变性及胶原纤维增生程度;定量RT-PCR检测COL-Ⅰ、Ⅲ、Ⅳ、TGF-β1、PDGF-BB mRNA表达,Western blot法检测肝组织中COL-Ⅰ与TGF-β1/ERK信号传导通路蛋白表达的变化。结果肝细胞脂肪性变与胶原形成程度随着造模时间的延长逐渐加重;COL-Ⅰ、ⅢmRNA与蛋白表达以2周、3.5周时显著上调,4.5周后降低,10周又显著上调,COL-Ⅳ表达水平在2~4.5周明显增加,随后下降至正常水平,p-ERK表达水平在各时相点增加与α-SMA表达水平有良好的一致性,p-ERK表达水平与TβRⅠ、TβRⅡ、PDGFRβ表达无良好一致性。结论在HF形成过成中肝组织内p-ERK可激活肝星状细胞表达α-SMA,加强COL-Ⅰ、ⅢmRNA转录。

Objective To observe the changes of TGF-β1/ERK signaling pathway protein and the expressions of type Ⅰ,Ⅲ,Ⅳ collagen in the process of hepatic fibrosis（HF） formation.Methods The SD rat model of hepatic fibrosis was made by carbon tetrachloride composite factors methods,that SD rats were fed with 10% ethanol,food with high-fat low-protein and injected subcutaneously with carbon tetrachloride once every four days for 6 weeks to establish hepatic fibrotic rats models.The degree of hepatocyte degeneration and hyperplasia collagen fibril were assessed by Masson stain at the week of 2,3.5,4.5,5,6 and 10 respectively,the expressions of COL-Ⅰ,Ⅲ,Ⅳ,TGF-β1 and PDGF-BB mRNA were detected by quantitative RT-PCR and the alteration of TGF-β1/ERK signaling pathway protein in liver tissue was detected by Western blot.Results The degree of degeneration fatty and hyperplasia collagen fibril were severity gradually following the prolonged time of model made.The expressions of typeⅠand Ⅲ collagen mRNA and protein were up-regulated significantly at the 2 weeks and 3.5 weeks,then decreased at the 4.5 weeks time point,but again up-regulated notably at 10 weeks.The expression of COL-Ⅳ obviously enhanced at 2～4.5 weeks,then reduced to normal.The expression of p-ERK increased at each time point and the expression of p-ERK had good coherence with the expression of α-SMA was well concordant,but it had no coherence with the expressions of TβRⅠ,TβRⅡ and PDGFRβ.Conclusion The transcription of typeⅠand Ⅲ collagen mRNA enhanced when p-ERK activated α-SMA of hepatic stellate cells of liver tissue in the process of HF formation.