Myofibrillogenesis regulator-1 attenuated hypoxia/reoxygenation-induced apoptosis by inhibiting the PERK/Nrf2 pathway in neonatal rat cardiomyocytes
Myofibrillogenesis regulator-1 attenuated hypoxia/reoxygenation-induced apoptosis by inhibiting the PERK/Nrf2 pathway in neonatal rat cardiomyocytes
复制标题
肌原纤维生成调节因子 1 通过抑制新生大鼠心肌细胞中的 PERK/Nrf2 通路来减轻缺氧/复氧诱导的细胞凋亡
DOI：
10.1007/s10495-014-1081-1
复制
发表时间：
2015-03-01
期刊：
影响因子：
7.2
通讯作者：
Liu, Xiu-Hua
中科院分区：
文献类型：
--
作者：
Tao, Tian-Qi;Wang, Xiao-Reng;Liu, Xiu-Hua
本研究旨在探讨肌原纤维生成调节因子-1（MR-1）通过蛋白激酶R样ER激酶（PERK）/核因子红细胞2相关因子2（Nrf 2）途径在缺氧/复氧（H/R）诱导的心肌细胞凋亡中的作用。为了解决这一目标，使用新生大鼠心肌细胞的H/R模型。使用腺病毒载体系统过表达MR-1，并使用MR-1特异性siRNA敲低MR-1。采用Annexin V/PI双染法、末端脱氧核苷酸转移酶介导的dUTP-生物素缺口末端标记法和Bcl-2/Bax比值检测细胞凋亡。Western blotting检测MR-1、葡萄糖调节蛋白78（GRP 78）、总PERK和磷酸化PERK、Nrf 2、转录激活因子4（ATF 4）、C/EBP同源蛋白（CHOP）、Bcl-2和Bax蛋白水平。免疫荧光染色用于评估Nrf 2的亚细胞定位。我们发现，H/R诱导的新生大鼠心肌细胞凋亡显着。MR-1过表达可减弱H/R诱导的细胞凋亡，降低GRP 78（P< 0.01）和CHOP表达（P< 0.05），增加Bcl-2/Bax比值（P< 0.01）。MR-1过表达抑制H/R诱导的PERK磷酸化、Nrf 2核转位和ATF 4表达（P< 0.01）。而MR-1基因敲低可加重H/R诱导的细胞凋亡，增加GRP 78和CHOP的表达（P< 0.05），降低Bcl-2/Bax比值（P< 0.01）。MR-1基因敲除显著增加H/R诱导的PERK磷酸化（P< 0.05）、Nrf 2核转位和ATF 4表达（P< 0.01）。这些发现表明MR-1通过抑制PERK/Nrf 2通路来抑制H/R诱导的心肌细胞凋亡。
The purpose of this study was to investigate the role of myofibrillogenesis regulator-1 (MR-1) in cardiomyocyte apoptosis induced by hypoxia/reoxygenation (H/R), through protein kinase R-like ER kinase (PERK)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. To address this aim, an H/R model of neonatal rat cardiomyocytes was used. MR-1 was overexpressed using an adenoviral vector system and knocked down using MR-1 specific siRNA. Apoptosis was assessed by using Annexin V/PI double staining, terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling assay, and the Bcl-2/Bax ratio. Western blotting was used to detect the protein levels of MR-1, glucose-regulated protein 78 (GRP78), total and phosphorylated PERK, Nrf2, activating transcription factor 4 (ATF4), C/EBP homologous protein (CHOP), Bcl-2 and Bax. Immunofluorescence staining was used to assess the subcellular location of Nrf2. We found that H/R induced significant apoptosis in neonatal rat cardiomyocytes. MR-1 overexpression attenuated H/R-induced apoptosis, decreased GRP78 (P< 0.01) and CHOP expression (P< 0.05), and increased the Bcl-2/Bax ratio (P< 0.01). MR-1 overexpression suppressed H/R-induced PERK phosphorylation, Nrf2 nuclear translocation, and ATF4 expression (P< 0.01). While MR-1 knockdown aggravated H/R-induced apoptosis, increased expression of GRP78 and CHOP (P< 0.05), and decreased the Bcl-2/Bax ratio (P< 0.01). MR-1 knockdown significantly increased H/R-induced PERK phosphorylation (P< 0.05), Nrf2 nuclear translocation, and ATF4 expression (P< 0.01). These findings suggest that MR-1 alleviates H/R-induced cardiomyocyte apoptosis through inhibition of the PERK/Nrf2 pathway.