Ca2+/钙调蛋白依赖性蛋白激酶Ⅱ在PDGF诱导肝星状细胞胶原合成中的作用

摘要

目的 观察Ca2+/钙调蛋白依赖性蛋白激酶Ⅱ(CaMKⅡ)对PDGF诱导下人肝星状细胞(hepatic stellate cell,HSC) collagen α1(Ⅰ)合成的影响.方法 CaMKⅡα siRNA转染对HSC内CaMKⅡα进行干扰,real-time PCR法检测HSC collagen α1(Ⅰ)及TIMP-1 mRNA的表达,Western blot法检测collagen α1(Ⅰ)及MMP-2、TIMP-1表达的变化,ELISA法检测HSC collagen α1(Ⅰ)分泌的变化.结果 CaMKⅡα siRNA可显著抑制PDGF诱导下HSC collagen α1(Ⅰ) 及MMP-2、TIMP-1的转录、蛋白表达以及collagen α1(Ⅰ)的分泌,差异均有统计学意义(P<0.05).结论 CaMKⅡα信号参与了PDGF诱导下HSC collagen α1(Ⅰ)的产生与分泌,同时通过抑制MMP-2、促进TIMP-1的表达而阻止胶原的降解,是肝纤维化发展过程中PDGF信号的重要调控分子和肝纤维化的潜在治疗靶点.%Objective To observe the effects of Ca2+/calmodulin-dependent protein kinase Ⅱ ( CaMK Ⅱ ) on PDGF-induced collagen α1 (Ⅰ) production in human hepatic stellate cells. Methods The knockdown of CaMK Ⅱ a was performed by CaMK Ⅱ α siRNA transient transfection. The mRNA and protein expression of collagen α1 (Ⅰ) , MMP-2 and TIMP-1 were determined by real-time PCR and Western blot, respectively. The secretion of collagen α1 (Ⅰ) in culture media was tested by ELISA. Results CaMK Ⅱ knockdown by CaMK Ⅱ a siRNA significantly inhibited collagen α1 (Ⅰ) expression and secretion in PDGF-induced HSCs. CaMK Ⅱ inhibition resulted in up-regulation of MMP-2 and down-regulation of TIMP-1. Conclusion CaMK Ⅱ α regulate PDGF-induced collagen α1 (Ⅰ) production and secretion, increase TIMP-1 expression and decrease MMP-2 expression. Our study shed light on CaMK Ⅱ as a crucial signal in PDGF-activated HSCs and a potential therapeutic target in hepatic fibrosis.