知识与财富的链接
本室以前已经报道了G蛋白偶联受体APJ的内源性配体多肽,apelin-13,通过激活ERK1/2促进大鼠血管平滑肌细胞增殖.本文研究14-3-3信号蛋白是否参与apelin-13促进大鼠血管平滑肌细胞增殖ERK1/2信号途径,探讨apelin/APJ系统的细胞信号转导机制.组织贴块法培养大鼠胸主动脉VSMCs;Western blotting方法检测14-3-3、pRaf-1、Raf-1、pERK1/2、ERK1/2、cyclinD1、cyclinE的表达;MTT方法观察14-3-3抑制剂Difopein对VSMCs的增殖作用;免疫共沉淀方法检测14-3-3和Raf-1蛋白复合物的形成.Western blotting方法结果显示,apelin-13(0、0.5、1、2、4μmol/L)浓度依赖性刺激大鼠VSMCs 14-3-3表达、Raf-1和ERK1/2磷酸化,以2μmol/L最为明显;2μmol/L apelin-13时间依赖性刺激大鼠VSMCs 14-3-3表达、Raf-1和ERK1/2磷酸化,在4 h增加最为显著;14-3-3蛋白抑制剂Difopein明显抑制apelin-13诱导的Raf-1磷酸化、ERK1/2磷酸化、cyclinD1及cyclinE表达;免疫共沉淀方法发现apelin-13诱导14-3-3与Raf-1结合增加,而Difopein明显抑制两者结合;MTT法显示Difopein明显抑制apelin-13诱导的血管平滑肌细胞增殖.上述结果表明,Apelin-13通过14-3-3/Raf-1复合物-ERK1/2信号转导通路促进大鼠血管平滑肌细胞增殖.
Previously,we found that G protein-coupled receptor APJ endogenous ligand apelin-13 stimulates vascular smooth muscle cells(VSMC) proliferation mediated in part by PKC-PI3K-ERK1/2-cyclinD1 signaling cascades.In this study,Raf-1-14-3-3 signaling in rat VSMCs proliferation stimulated by apelin-13 was further investigated.Cell proliferation was measured with MTT assay.Expression of PI3K,phospho-PI3K,Raf-1,phospho-Raf-1,ERK1/2,phospho-ERK1/2,cyclinD1 and cyclinE were detected byWestern blotting.14-3-3 protein c...