Mitochondria-Targeted Antioxidant Peptide SS31 Prevents Hypoxia/Reoxygenation- Induced Apoptosis by Down-Regulating p66Shc in Renal Tubular Epithelial Cells
Mitochondria-Targeted Antioxidant Peptide SS31 Prevents Hypoxia/Reoxygenation- Induced Apoptosis by Down-Regulating p66Shc in Renal Tubular Epithelial Cells
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DOI：
10.1159/000354463
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发表时间：
2013-01-01
影响因子：
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通讯作者：
Zeng, Li
中科院分区：
文献类型：
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作者：
Zhao, Wen-Yu;Han, Shu;Zeng, Li
背景/目标：缺血/再灌注损伤在肾移植中起着至关重要的作用，是急性肾损伤和移植物功能延迟恢复的重要危险因素。线粒体靶向的抗氧化肽SS 31已被证明通过抑制氧化应激来减轻缺血/再灌注损伤。本研究旨在探讨SS 31预处理是否能通过抑制p66 Shc来减轻缺氧/复氧（H/R）所致的脑损伤。研究方法：将培养的大鼠肾近端肾小管上皮细胞系NRK 52 E置于缺氧（5%CO2，1%O-2，94%N-2）24 h后，复氧（5%CO2，21%O-2，74%N-2）6 h。在处理前4 h将SS 31加入培养基中。然后测定细胞活力、凋亡和氧化应激水平。此外，进行蛋白质印迹分析以确定p66 Shc、p-p66 Shc、细胞色素c和半胱天冬酶-3的表达。结果：H/R诱导NRK 52 E细胞凋亡，并伴有总p66 Shc和p-p66 Shc的激活。用SS 31预处理或过表达显性失活Ser 36突变体p66 Shc（p66 Shc S36 A）或p66 Shc siRNA可防止细胞死亡，而SS 31的保护作用可被过表达野生型p66 Shc完全阻断。此外，SS 31预处理减少H/R诱导的细胞内氧化应激，细胞色素c易位到细胞质中，并通过抑制p66 Shc激活caspase-3。结论：本研究表明，SS 31预处理对H/R诱导的人肾小管上皮细胞凋亡具有保护作用，其机制与抑制p66 Shc有关。版权所有（C）2013 S. Karger AG，巴塞尔
Background/Aims: Ischemia/reperfusion injury plays a crucial role in renal transplantation and represents a significant risk factor for acute kidney injury and delayed graft function. Mitochondria-targeted antioxidant peptide SS31 has been shown to attenuate ischemia/ reperfusion injury by inhibiting oxidative stress. The present study was carried out to investigate whether the pretreatment of SS31 could reduce hypoxia/reoxygenation (H/R)-induced injury by inhibiting p66Shc. Methods: The cultured rat renal proximal tubular cell line NRK52E cells were exposed to 24 h hypoxia (5% CO2, 1% O-2, 94% N-2) followed by 6 h reoxygenation (5% CO2, 21% O-2, 74% N-2). SS31 was added to the culture medium 4 h prior to the treatment. Then the cell viability, apoptosis, and oxidative stress levels were determined. In addition, western blot analysis was performed to determine the expression of p66Shc, p-p66Shc, cytochrome c, and caspase-3. Results: H/R induced apoptotic cell death, accompanied with activation of total and p-p66Shc in NRK52E cells. Pretreatment with SS31 or overexpression of a dominant-negative Ser36 mutant p66Shc (p66Shc S36A) or p66Shc siRNA prevented cell death, whereas the protection effect of SS31 was completely blocked by overexpression of wild-type p66Shc. Furthermore, SS31 pretreatment reduced H/R-induced intracellular oxidative stress, cytochrome c translocation to the cytoplasm, and caspase-3 activation through inhibiting p66Shc. Conclusion: This study revealed that SS31 pretreatment serves a protective role against H/R-induced apoptosis of human renal tubular epithelial cells, and the mechanism is related to suppression of p66Shc. Copyright (C) 2013 S. Karger AG, Basel