摘要
心肌细胞凋亡性死亡是低氧发生时的重要病理学特征,但低氧诱导的心肌细胞凋亡的调控机制尚未完全阐明。E2F6是E2F转录因子家族成员之一, 我们新近的研究证实其具有抑制DNA损伤诱导的细胞凋亡作用。但是,E2F6 是否参与了低氧诱导的心肌细胞凋亡的调控尚不清楚。在本研究中,我们初步探讨了E2F6 在物理性低氧及化学性低氧模拟物诱导大鼠心肌细胞系H9c2 细胞凋亡中的表达特征。结果表明:物理性低氧、化学性低氧模拟物去铁胺(desferrioxamine, DFO)和氯化钴(cobaltchloride, CoCl2)均能有效诱导 H9c2 细胞发生凋亡。在物理性低氧及 CoCl2 诱导的 H9c2 细胞凋亡中,内源性 E2F6 mRNA 表达明显下调,但蛋白表达没有明显变化。而在DFO 诱导的凋亡中,内源性E2F6 mRNA及蛋白表达均发生明显下调。这些结果提示,E2F6 可能参与调控DFO 模拟低氧诱导的H9c2 细胞凋亡,而对物理性低氧及CoCl2 模拟低氧诱导的细胞凋亡敏感性较低。此外,DFO 模拟低氧诱导的细胞凋亡机制可能与物理性低氧及 CoCl2 模拟低氧诱导的细胞凋亡机制不同。
Apoptosis can be caused by hypoxia, a major factor during ischemic injury, in cardiomyocytes. However, the regulatory mechanisms underlying hypoxia-induced cardiomyocyte apoptosis have not yet been fully understood. E2F6, an identified E2F family member, has been demonstrated to repress DNA damage-induced apoptosis in our recent study. However, it is unclear whether E2F6 is involved in hypoxia-induced apoptosis. In this study, we determined the expression property of E2F6 during hypoxia-induced apoptosis in H9c2 cells, a rat ventricular myoblast cell line. The results showed that physical hypoxia and chemical hypoxia-mimetic agents desferrioxamine （DFO） and cobalt chloride （CoCl2） induced apoptosis in H9c2 cells. Physical hypoxia- and CoCl2-induced apoptosis was accompanied with a downregulation of endogenous E2F6 mRNA expression, but not protein expression. DFO treatment resulted in a significant downregulation of both mRNA and protein expressions of endogenous E2F6. These results suggest that E2F6 may be involved in DFO-induced apoptosis, while it is less sensitive in physical hypoxia- and CoCl2-induced apoptosis in H9c2 cells. In addition, the apoptosis induced by DFO may share different pathways from that induced by physical hypoxia and CoCl2.
出处
《生理学报》
CAS
CSCD
北大核心
2008年第1期1-10,共10页
Acta Physiologica Sinica
基金
supported by the National Basic Research Program of China (No. 2006CB504100)
Major and General Programs of theNational Natural Science Foundation of China (No. 30393133, 30370536)
Knowledge Innovation Program of the Chinese Academy ofSciences (No. KSCX2-YW-R-75)
