PARP1对NFATs的调控在病理性心肌肥大中的作用

目的 探究多聚腺苷二磷酸核糖聚合酶1(PARP1)与活化T细胞核转录因子3(NFATc3)、NFATc4在病理性心肌肥大中的调控关系及其机制。方法 采用异丙肾上腺素(ISO)刺激原代心肌细胞24 h,在细胞水平建立心肌肥大模型;SD大鼠皮下注射ISO,在动物水平建立心肌肥大模型。使用核蛋白抽提试剂盒分离胞质和胞核蛋白,免疫印迹法检测相应蛋白的出入核及蛋白表达水平变化;利用免疫荧光,检测NFATc3、NFATc4的亚细胞定位;采用腺病毒感染的方法进行PARP1过表达,通过转染小干扰RNA进行PAPR1的敲低。结果 在细胞及动物水平上,ISO成功建立心肌肥大模型,均观察到ISO引起NFATc3和NFATc4在细胞核的聚集增加;同时,ISO可致PARP1的PAR化酶活性上升;单独过表达PARP1可诱导NFATc3和NFATc4入核增加,敲低PARP1抑制了ISO引起的入核增加,而给予PARP1抑制剂3AB则可一定程度逆转NFATc3和NFATc4的入核转位。结论 ISO可能通过诱导PARP1酶活性的上调,进而促进NFATc3和NFATc4的转位入核,从而诱导心肌肥大的发生。

Effect of PARP1 through regulating NFATs on cardiac hypertrophy

Aim To investigate the interaction and mechanism of PARP1 and NFATc3,NFATc4 in ISO-induced pathological cardiac hypertrophy.Methods To establish the model of cardiac hypertrophy in vitro and in vivo ,primary neonatal rat cardiomyocytes were treated with ISO (10 μmol·L^-1 ) for24 h;SD rats were subcutaneously injected with1.2 mg·kg^-1 ·d^-1 ISO for 7 d.The nuclear and cytoplasmic proteins were separated by Cellytic Nuclear Extraction Kit.The subcellular localization of NFATc3 and NAFTc4 were detected by Western blot and immunofluorescence.The recombinant adenovirus (Ad-PARP1) infection was used to overexpress PARP1 and knockdown PARP1 by transfecting with siRNA of PARP1 in cardiomyocytes.Results The models of cardiac hypertrophy were successfully built both in vivo and vitro by ISO.It was determined that NFATc3 and NFATc4 were transfered into the nuclear from the cytoplasm in primary neonatal rat cardiomyocytes (NRCMs) after being treated with ISO.And the enzymatic activity of PARP1 was boosted in ISO-treated group.Overexpression of PARP1 promoted the nuclear translocation of NFATc3 and NFATc4 in cardiomyocytes,while knockdown of PARP1 could reverse the nuclear translocation induced by ISO.PARP1 inhibitor3AB retarded ISO-induced nuclear transportation of NFATc3 and NFATc4 to some extent.Conclusions ISO leads to the up-regulation of enzymatic activity of PARP1 and promotes nuclear translocation of NFATc3 and NFATc4,thus aggravating cardiac hypertrophy.