敲低NLRX1可上调线粒体融合蛋白并减轻缺氧心肌细胞凋亡  

NLRX1 knockdown up-regulates expression level of mitochondrial fusion protein and attenuates hypoxia induced cardiomyocyte death

作　　者：王林一 贺广祥 梁郡 史睿 李慢 裴建明 杨彦玲[1] 李军 WANG Lin-yi;HE Guang-xiang;LIANG Jun;SHI Rui;LI Man;PEI Jian-ming;YANG Yan-ling;LI Jun(School of Medicine,Yan’an University,Yan’an 716000,Shaanxi,China;Department of Physiology and Pathophysiology,School of Basic Medical Science,Air Force Medical University,Xi’an 710032,Shaanxi,China)

机构地区：[1]延安大学医学院,陕西延安716000 [2]空军军医大学基础医学院生理与病理生理学教研室,陕西西安710032

出　　处：《心脏杂志》2023年第4期373-379,共7页Chinese Heart Journal

基　　金：国家自然科学基金项目(82170249,82070051,82071235)。

摘　　要：目的探究模式识别受体NOD样受体家族成员X1(NLRX1)对心肌细胞缺氧损伤的影响及其分子机制。方法分离培养SD大鼠乳鼠原代心肌细胞,转染NLRX1-siRNA 48 h后,给予不同时间的氧糖剥夺模拟心肌缺血。采用CCK-8法检测细胞活力,流式细胞术检测细胞凋亡,Western blot检测NLRX1蛋白和线粒体融合相关蛋白(Opa1、Mfn1、Mfn2)表达水平,激光扫描共聚焦显微镜观察线粒体形态。结果NLRX1在心肌细胞中高表达,心肌细胞氧糖剥夺后NLRX1总蛋白水平不变,胞浆NLRX1上调(P<0.01)。与对照组相比,siRNA沉默NLRX1可上调线粒体融合蛋白Mfn2和Opa1的表达水平,促进缺氧心肌细胞线粒体融合,减轻缺氧诱导的心肌细胞凋亡(P<0.05)。结论免疫调节分子NLRX1可能具有调控线粒体融合蛋白的作用,阻抑NLRX1可上调融合分子Mfn2,Opa1蛋白表达,减轻缺氧心肌损伤。AIM To investigate the effects of pattern recognition receptor NLRX1 on cardiomyocytes upon hypoxia injury and the underlying molecular mechanisms.METHODS Primary neonatal rat ventricular myocytes(NRVMs)of SD rats were isolated and cultured.NRVMs were transfected with NLRX1-siRNA for 48 hours and then subjected to hypoxia and glucose deprivation for different times to simulate myocardial ischemia.Cell viability was determined by CCK-8 kit and cell apoptosis was analyzed with flow cytometry.Protein expression levels of NLRX1 and mitochondrial fusion related proteins(Opa1,Mfn1,Mfn2)were determined by Western blot and mitochondrial morphology was analyzed with laser scanning confocal microscopy.RESULTS NLRX1 was highly expressed in cardiomyocytes.Although total protein level of NLRX1 was not altered,cytoplasmic NLRX1 was upregulated in NRVMs upon hypoxia and glucose deprivation(P<0.01).Compared with those in control group,NLRX1-siRNA up-regulated expression levels of mitochondrial fusion protein Mfn2 and Opa1,promoted mitochondrial fusion of hypoxic cardiomyocytes and reduced hypoxia induced cardiomyocyte death(P<0.05).CONCLUSION NLRX1 modulates the expression of mitochondrial fusion proteins Mfn2 and Opa1,and the inhibition of NLRX1 up-regulates the protein levels of Mfn2 and Opa1,which contributes to reduced cardiomyocytes injury upon hypoxia.

关 键 词：NLRX1 线粒体融合 心肌细胞凋亡 

分 类 号：R56[医药卫生—呼吸系统]