【摘要】 目的探讨G蛋白偶联受体激酶2(GRK2)在心肌纤维化发生过程中的作用。方法皮下注射异丙肾上腺素诱导大鼠心肌纤维化,采用HE染色观察模型大鼠心肌组织学变化,差速贴壁法分离培养心肌成纤维细胞,检测成纤维细胞中GRK2的表达和胶原Iα含量,采用siRNA干涉法抑制GRK2表达,采用cAMP检测试剂盒检测细胞内cAMP含量。结果 HE染色显示大鼠心肌纤维化模型心肌细胞出现坏死、肥大、淋巴细胞浸润等变化。Western blotting结果显示,异丙肾上腺素诱导模型大鼠心肌成纤维细胞中GRK2表达增加(P<0.05),胶原Iα表达增加(P<0.01)。GRK2特异性siRNA可以显著抑制GRK2的表达(P<0.05)。cAMP含量分析显示,异丙肾上腺素诱导心肌纤维化模型大鼠中心肌组织cAMP含量明显下降(P<0.01),在siRNA抑制GRK2表达后,心肌组织中cAMP水平显著升高(P<0.05)。结论采用siRNA法抑制GRK2表达可以增加细胞内cAMP的含量。GRK2有望成为心肌纤维化防治靶点。更多还原

【Abstract】 Objective To study the role of G protein-coupled receptor kinase 2(GRK2) on myocardial fibrosis.Methods Rat model of myocardial fibrosis was established by subcutaneous injection with isoproterenol.Myocardial histological changes of the rats w ere tested by microscope after hematoxylin and eosin staining(HE).Myocardial fibroblasts w ere isolated and cultured w ith differential anchoring velocity.The expressions of GRK2 and collagen type Iα w ere examined by w estern blotting.The cAMP level w as tested after GRK2 gene w as silenced by siRNA.Results HE staining show ed myocardium necrosis,hypertrophy,and lymphocytic infiltration.The expression of GRK2(P < 0.05) and collagen type Iα(P <0.05) were up-regulated in isoproterenol-induced rats.The level of cAMP decreased significantly in isoproterenol-induced rats(P < 0.05).How ever,the level of cAMP increased after GRK2 gene silenced by siRNA(P <0.05).Conclusion The intracellular cAMP increased after GRK2 gene expression is silenced by siRNA.GRK2 may serve as a novel potential therapeutic target.更多还原