Nur77 在缺氧/ 复氧诱导的心肌细胞凋亡中的作用及其机制的研究

目的:观察Nur77通过线粒体转位对缺氧/复氧(H/R)诱导的心肌细胞凋亡的影响。方法:原代培养l-2天SD大鼠心肌细胞,建立H/R模型。随机分为正常对照组、H/R组、Nur77组,采用免疫荧光检测横纹肌肌动蛋白(α-actin)鉴定心肌细胞;采用TUNEL染色法及Caspase-3酶活性检测心肌细胞凋亡情况;采用Western blot检测细胞核及线粒体Nur77蛋白表达、线粒体及胞浆Omi/HtrA2蛋白表达。结果:H/R组细胞核中Nur77蛋白表达明显低于正常对照组;而在线粒体中则相反。Nur77组线粒体中的Omi/HtrA2蛋白表达明显低于正常对照组;而在胞浆中则相反。结论:在心肌细胞H/R损伤时,Nur77线粒体转位促使Omi/HtrA2蛋白从线粒体释放入胞浆,从而导致心肌细胞凋亡。

The Effects and Mechanism Study of Nur77 on Hypoxia/Reoxygenation-Induced Apoptosis in Rat Cardiomyocyte

Objective: To investigate mitochondrial translocation of Nur77 on hypoxia/reoxygenation-induced apoptosis in rat cardiomyocyte.Methods: A model of cultured cardiomyocytes from neonatal rats of hypoxia/reoxygenation-induced apoptosis was established,and randomly devided into three groups: control group,H/R group and Nur77 group.Immunohistochemistry of α-actin with confocal microscopy was used to detect the identification in cardiomyocytes.TUNEL staining was used to detect morphological changes of apoptotic cells.Colorimetry was used to detect caspase-3 activity was used to detect apoptotic rates.Expression of Nur77 protein of nucleus and mitochondria was measured by Western blot.Expression of Omi/HtrA2 protein of mitochondria and cytosolic was measured by Western blot.Results:Compared with that in control and H/R groups,the expression of Nur77 protein of nucleus was markedly attenuated in H/R groups,but it was opposite in mitochondria.Compared with that in control and Nur77groups,the expression of Omi/HtrA2 protein of mitochondria was markedly attenuated in Nur77 groups,but it was opposite in cytosolic.Conclusion:Mitochondrial translocation of Nur77 mediates Omi/HtrA2 to release on hypoxia/reoxygenation-induced apoptosis.