结缔组织生长因子通过ERK1/2和PI3K信号通路促进大鼠肝星状细胞迁移和基质金属蛋白酶2表达

目的：研究结缔组织生长因子（CTGF）对大鼠肝星状细胞（HSC）迁移及基质金属蛋白酶2（MMP-2）表达及活化的影响。方法分别应用RT-PCR和Western blotting法检测MMP-2表达，明胶酶谱法检测MMP-2的活性；运用Western blotting法检测ERK1/2和Akt的磷酸化水平。运用Transwell小室检测肝星状细胞迁移能力。结果 CTGF呈剂量依赖性促进大鼠HSC中MMP-2 mRNA和蛋白表达；同时CTGF能够促进HSC迁移，MMP-2特异性抑制剂能够抑制CTGF的促迁移作用。ERK1/2和PI3K抑制剂能够显著抑制CTGF诱导的MMP-2表达以及CTGF促进HSC的迁移作用。结论 MMP-2表达和活性的增强在CTGF促进HSC迁移过程中发挥着重要作用，ERK1/2和PI3K信号通路在CTGF促进MMP-2表达发挥关键作用。

CTGF promoting migration and MMP-2 expression via ERK1/2 and PI3K pathway in rat hepatic stellate cells

Objective To identify the role of connective tissue growth factor （CTGF） in hepatic stellate cell （HSC） migration and its effects on gelatinase matrix metalloproteinase-2 （MMP-2） expression and activation. Methods The expression of MMP-2 was assessed by RT-PCR and Western blotting analyses. MMP-2 activity was evaluated by zymography. ERK1/2 and Akt phosphorylation were determined by Western blotting analysis. HSC migration was performed using Transwell cell culture chambers. Results The expression of MMP-2 mRNA and protein in HSCs were substantially increased by CTGF treatment in a dose-dependent manner. In addition, CTGF could promote HSC migration, and the addition of MMP-2-specific inhibitor impaired this phenomenon. To study the intracellular signaling pathways involved in CTGF-induced MMP-2 expression, we evaluated the effects of different kinase inhibitors. The inhibitors of extracellular signal-regulated kinase 1/2 （ERK1/2） and phosphatidyl inositol 3-kinase （PI3K） abrogated CTGF-elicited MMP-2 upregulation and significantly reduced CTGF-induced invasiveness of HSC. Conclusion MMP-2 plays an important role in the invasive effects of CTGF on HSC. ERK1/2 and PI3K are the main signals involved in CTFG-mediated MMP-2 expression.