血小板源生长因子通过PI3K/AKT途径促肝星状细胞增殖与Ⅰ型胶原合成

PDGF is dependent on PI3K/AKT pathway to induce proliferation of Hsc and synthesis of typeⅠcollagen

目的研究磷脂酰肌醇3激酶(PI3K)特异性的抑制剂LY294002对血小板源生长因子(PDGF)诱导的肝星状细胞增殖与I型胶原合成的影响,并初步探讨P13K信号通路在PDGF诱导肝星状细胞活化中的机制。方法HSC细胞用LY294002和PDGF-BB共同孵育处理。收集细胞和培养液上清。细胞增殖用噻唑蓝(MTT)法检测,I型胶原蛋白用ELISA法检测,逆转录-聚合酶链反应(RT-PCR)法检测I型胶原mRNA的表达。利用P13K通路下游效应物AKT作为活化指标,ELISA法检测AKT和磷酸化AKT蛋白的表达。结果PDGF-BB能激活P13K通路,并导致AKT磷酸化。LY294002抑制P13K信号通路后,PDGF-BB刺激的HSC-T6增殖与促I型胶原合成作用被抑制。结论PDGF促HSC增殖和I型胶原合成是通过P13K信号通路,其作用可以被P13K抑制剂LY294002抑制。

Objective To investigate the effect of LY294002 （a specific inhibitor of PI3K） on the proliferation and type I collagen synthesis of HSCs stimulated by PDGF and explore the mechanism of PI3K pathway activated by PDGF. Methods Rat HSCs stimulated by PDGF-BB were incubated with different concentrations of LY294002. Cell proliferation was assessed by MTT colorimetfic assay. The type I collagen protein was assayed by ELISA. The mRNA of type I collagen was examined by RT-PCR. The activation of P/3K pathway estimated by phosphorylated akt by EIASA. Results LY294002 could significantly inhibit the proliferation of HSCs stimulated by PDGF-BB in a dose-dependent manner. LY294002 could down-regulate the synthesis of type I collagen in HSCs. PDGF-BB could activate PI3K, which leading to the phosphorylation of akt. Block the PI3K pathway inhibited the biological effect of PDGF-BB on HSCs. Condttsion PDGF activates HSCs through PI3K pathway,which could inhibited by PI3K inhibitor. PI3K signaling pathway is a critical pathway for PDGF-induce HSC proliferation, and PI3K also is an important modulator of type I collagen synthesis.