血小板衍生生长因子体外对大鼠肝星状细胞表达细胞外基质的影响

摘要

目的 研究体外大鼠肝星状细胞(HSC)中血小板衍生生长因子(PDGF)信号通路的激活对于HSC表达细胞外基质(ECM)的影响.方法 分离、纯化大鼠原代HSC并体外培养;以MTT实验检测PDGF对HSC增殖的作用;以Western blot和Real-time PCR方法分别检测PDGF对PDGF-βR与CTGF、ECM成分α-SMA、α1(I)collagen和fibronectin,以及调控ECM降解平衡的MMP-2和TIMP-1表达的影响.结果 MTT实验结果表明PDGF以剂量依赖性和时间依赖性的方式促进HSC的增殖.PDGF可以促进其受体PDGF-βR和CTGF的蛋白与mRNA表达.PDGF还可明显上调ECM成分α-SMA、α1(I)collagen和fibronectin的表达.此外,PDGF影响ECM的降解平衡,表现为TIMP-1的表达上调,而MMP-2的表达下调.结论 PDGF/PDGF-βR信号转导途径可明显促进HSC活化与ECM生成,抑制ECM降解.所得结果可以为药物阻滞PDGF信号转导从而抑制肝纤维化提供依据.%Aim To investigate the impacts of platelet-derived growth factor ( PDGF ) signaling on extracellular matrix ( ECM ) secretion in rat hepatic stellate cells ( HSCs ) in vitro. Methods The primary rat HSCs were isolated, purified and cultured in vitro. The MTT assay was used to detect the effects of PDGF on HSC proliferation. Western blot assay and Real-time PCR were used to detect the expression of PDGF-(3 R and CTGF, the expression of ECM components a-SMA, al ( I ) collagen and fibronectin, and the expression of ECM regulatory proteins MMP-2 and TIMP-1, respectively. Results MTT assay showed that PDGF promoted HSC proliferation in vitro in a dose- and time-dependent manner. PDGF stimulated its receptor PDGF-(3R and CTGF expression. Activated PDGF signaling further upregulated the protein and mRNA levels of a-SMA,al( I )collagen and fibronectin. Moreover, the dynamic ECM equilibrium was affected by PDGF, which upregulated TIMP-1, but downregualted MMP-2 expression. Conclusion PDGF/PDGF-pR signaling cascade can significantly stimulate HSC activation and ECM production, and inhibit ECM degradation. Our results may provide evidence for developing antifibrotic drugs targeting PDGF pathway.