Heat shock suppresses the permeability transition in rat liver mitochondria
Heat shock suppresses the permeability transition in rat liver mitochondria
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DOI：
10.1074/jbc.m300153200
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发表时间：
2003-05-09
影响因子：
4.8
通讯作者：
Lemasters, JJ
中科院分区：
文献类型：
--
作者：
He, LH;Lemasters, JJ
热休克蛋白抑制各种细胞类型中的细胞凋亡和坏死死亡。然而，热休克蛋白保护的具体机制仍不清楚。为了验证热休克蛋白通过阻断线粒体通透性转换(MPT)孔的开放来抑制细胞死亡的假设，采用差速离心法分离了热预适应大鼠肝脏的线粒体。热休克可抑制50um CaCl2+5um HgCl2或1um mastoparan和单独200um CaCl2诱导的MPT开孔。热休克后半峰肿胀时间延迟15min或更长时间。热休克还增加了高剂量HgCl2和Mastoparan诱导的非调控(钙非依赖性和环孢素A不敏感)MPT孔洞开放阈值。热休克处理使线粒体活性氧的形成减少了27%，但不改变线粒体呼吸、膜电位、钙摄取或肝线粒体和胞浆提取物中的总谷胱甘肽。Western印迹分析显示，热休克后线粒体HSP25增加，而Hsp10、Hsp60、Hsp70、Hsp75、亲环素D和电压依赖性阴离子通道无明显变化。这些结果表明，热休克可以抵抗MPT孔的张开，这可能有助于热休克对细胞损伤的保护。
Heat shock proteins inhibit apoptotic and necrotic cell death in various cell types. However, the specific mechanism underlying protection by heat shock proteins remains unclear. To test the hypothesis that heat shock proteins inhibit cell death by blocking opening of mitochondrial permeability transition (MPT) pores, mitochondria from heat-preconditioned rat livers were isolated by differential centrifugation. Heat shock inhibited MPT pore opening induced by 50 muM CaCl2 plus 5 muM HgCl2 or 1 muM mastoparan and by 200 muM CaCl2 alone. Half-maximal swelling was delayed 15 min or more after heat shock compared with control. Heat shock also increased the threshold of unregulated (Ca2+-independent and cyclosporin A-insensitive) MPT pore opening induced by higher doses of HgCl2 and mastoparan. Heat shock treatment decreased mitochondrial reactive oxygen species formation by 27% but did not change mitochondrial respiration, membrane potential, Ca2+ uptake, or total glutathione in mitochondrial and cytosolic extracts of liver. Western blot analysis showed that mitochondrial Hsp25 increased, whereas Hsp10, Hsp60, Hsp70, Hsp75, cyclophilin D, and voltage-dependent anion channel did not change after heat shock. These results indicate that heat shock causes resistance to opening of MPT pores, which may contribute to heat shock protection against cellular injury.