CaMKⅡ/ERK信号通路在TGFβ1诱导肝星状细胞增殖中的作用

Effects of CaMKⅡ/ERK signal pathway on TGFβ1-induced human hepatic stellate cell proliferation

目的观察Ca2+/钙调蛋白依赖性蛋白激酶Ⅱ(Ca2+/calmodulin-dependent protein kinaseⅡ,CaMKⅡ)/细胞外信号调节激酶(extracellular signal regulated kinase,ERK)信号通路对TGFβ1诱导下人肝星状细胞(hepatic stellate cell,HSC)增殖的影响。方法 CaMKⅡαsiRNA转染对HSC内CaMKⅡα进行干扰,ERK特异性抑制剂PD98059对ERK信号进行抑制,MST法检测HSC的增殖,Western blotting法检测ERK、p-ERK、JNK、p-JNK表达的变化。结果 CaMKⅡαsiRNA可显著抑制TGFβ1诱导的HSC增殖,差异有统计学意义(P<0.05),对ERK的表达无明显影响,但显著提高p-ERK的表达水平,差异有统计学意义(P<0.05);PD98059可明显抑制TGFβ1诱导的HSC增殖,差异有统计学意义(P<0.05)。结论 CaMKⅡ/ERK信号参与了TGFβ1诱导的HSC增殖,是肝纤维化发展过程中的重要信号通路。

Objective To observe the effects of CaMK Ⅱ/ERK signal pathway on TGFβ1-induced human hepatic stellate cell （HSC） proliferation. Methods The knockdown of CaMK Ⅱ a was performed by CaMK II a siRNA transient transfection, ERK and JNK were inhibited by their specific inhibitor PD98059 and SP600125, respectively. HSC prolif- eration was assessed by MST. The protein expression of ERK, p-ERK, JNK and p-JNK were determined by Western blotting. Results CaMK Ⅱ knockdown by CaMK Ⅱ a siRNA significantly inhibited TGFfβ1-induced HSC proliferation. CaMK II inhibition had no effect on ERK, JNK and p-JNK expression but resulted in up-regulation of p-ERK. Conclu- sion CaMK Ⅱ regulates TGFβ1-induced HSC proliferation through ERK but not JNK mechanism. CaMK Ⅱ/ERK is a crucial signaling pathway in TGFβ1-activated HSCs proliferation.