Combined and individual mitochondrial HSP60 and HSP10 expression in cardiac myocytes protects mitochondrial function and prevents apoptotic cell deaths induced by simulated ischemia-reoxygenation
Combined and individual mitochondrial HSP60 and HSP10 expression in cardiac myocytes protects mitochondrial function and prevents apoptotic cell deaths induced by simulated ischemia-reoxygenation
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DOI：
10.1161/01.cir.103.13.1787
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发表时间：
2001-04-03
期刊：
影响因子：
37.8
通讯作者：
Dillmann, WH
中科院分区：
文献类型：
--
作者：
Lin, KM;Lin, B;Dillmann, WH
背景——线粒体热休克蛋白HSP60和HSP10形成线粒体伴侣蛋白复合物，先前的研究表明，当心肌细胞遭受模拟缺血时，它们的表达增加可发挥针对缺血性损伤的保护作用，但这种保护作用发生的更详细机制目前尚不清楚。我们想要确定 HSP60 和 HSP10 是否可以对模拟缺血和复氧 (SI/RO) 诱导的细胞凋亡发挥保护作用，以及这种保护作用是否是由于线粒体细胞色素 c 释放和 caspase-3 激活减少以及通过保存电子传递链复合物来保存 ATP 水平所致。此外，我们还探讨了HSP60或HSP10自身表达增加是否会发挥保护作用。方法和结果-我们使用腺病毒载体在大鼠新生心肌细胞中一起或单独过表达HSP60和HSP10，然后对心肌细胞进行SI/RO。心肌细胞中的细胞死亡和凋亡通过酶释放、DNA 片段化和 caspase-3 激活等参数进行量化。 HSP60和HSP10组合以及HSP60或HSP10单独的过表达可以保护心肌细胞免于凋亡。这种保护伴随着 SI/RO 后线粒体细胞色素 c 释放和 caspase-3 活性的减少，以及 ATP 恢复和线粒体中复合物 III 和 IV 活性的增加。结论-这些结果表明：线粒体伴侣蛋白 HSP60 和 HSP10 组合或单独在维持线粒体完整性和 ATP 生成能力方面发挥着重要作用，这是决定经历缺血/再灌注损伤的心肌细胞存活的关键因素。
Background-The mitochondrial heat-shock proteins HSP60 and HSP10 form a mitochondrial chaperonin complex, and previous studies have shown that their increased expression exerts a protective effect against ischemic injury when cardiac myocytes are submitted to simulated ischemia, The more detailed mechanisms by which such a protective effect occurs are currently unclear. We wanted to determine whether HSP60 and HSP10 could exert a protection against simulated ischemia and reoxygenation (SI/RO)-induced apoptotic cell death and whether such protection results from decreased mitochondrial cytochrome c release and caspase-3 activation and from the preservation of ATP levels by preservation of the electron transport chain complexes. In addition, we explored whether increased expression of HSP60 or HSP10 by itself exerts a protective effect.Methods and Results-We overexpressed HSP60 and HSP10 together or separately in rat neonatal cardiac myocytes using an adenoviral vector and then subjected the myocytes to SI/RO. Cell death and apoptosis in myocytes were quantified by parameters such as enzyme release, DNA fragmentation, and caspase-3 activation. Overexpression of the combination of HSP60 and HSP10 and of HSP60 or HSP10 individually protected myocytes against apoptosis. This protection is accompanied by decreases in mitochondrial cytochrome c release and in caspase-3 activity and increases in ATP recovery and activities of complex III and IV in mitochondria after SI/RO.Conclusions-These results suggest: that mitochondrial chaperonins HSP60 and HSP10 in combination or individually play an important role in maintaining mitochondrial integrity and capacity for ATP generation, which are the crucial factors in determining survival of cardiac myocytes undergoing ischemia/reperfusion injury.