AMP-activated protein kinase confers protection against TNF-α-induced cardiac cell death
AMP-activated protein kinase confers protection against TNF-α-induced cardiac cell death
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DOI：
10.1093/cvr/cvp166
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发表时间：
2009-10-01
影响因子：
10.8
通讯作者：
Rodrigues, Brian
中科院分区：
文献类型：
--
作者：
Kewalramani, Girish;Puthanveetil, Prasanth;Rodrigues, Brian
虽然5'腺苷单磷酸活化蛋白激酶（AMPK）在调节心脏代谢中发挥了重要作用，但AMPK的一个较少研究的作用是其防止心脏细胞死亡的能力。使用已建立的AMPK激活剂，如地塞米松（DEX）或二甲双胍（MET），本研究的目的是确定AMPK激活是否阻止肿瘤坏死因子- α (tnf - α)诱导的成年大鼠心室心肌细胞凋亡。心肌细胞与DEX、MET或tnf - α孵育不同时间（0-12小时）。通过测量caspase-3活性和Hoechst染色来评估tnf - α诱导的细胞损伤。采用蛋白和基因估计技术来确定AMPK激活剂介导tnf - α诱导的心肌细胞凋亡的机制。肌细胞与tnf - α一起培养8小时，增加了caspase-3的激活和凋亡细胞的死亡，这一作用被DEX和MET所消除。DEX和MET的有益作用与AMPK的刺激有关，这导致Bad磷酸化的快速和持续增加。这一事件减少了Bad和Bcl-xL之间的相互作用，限制了细胞色素c的释放和caspase-3的激活。添加化合物C抑制AMPK可减少Bad磷酸化，阻止AMPK对tnf - α诱导的细胞毒性的有益作用。我们的数据表明，尽管DEX和MET分别被用作抗炎剂或胰岛素增敏剂，但它们磷酸化AMPK的共同特性通过调节Bad和线粒体凋亡机制促进心肌细胞存活。
Although a substantial role for 5' adenosine monophosphate-activated protein kinase (AMPK) has been established in regulating cardiac metabolism, a less studied action of AMPK is its ability to prevent cardiac cell death. Using established AMPK activators like dexamethasone (DEX) or metformin (MET), the objective of the present study was to determine whether AMPK activation prevents tumour necrosis factor-alpha (TNF-alpha) induced apoptosis in adult rat ventricular cardiomyocytes.Cardiomyocytes were incubated with DEX, MET, or TNF-alpha for varying durations (0-12 h). TNF-alpha-induced cell damage was evaluated by measuring caspase-3 activity and Hoechst staining. Protein and gene estimation techniques were employed to determine the mechanisms mediating the effects of AMPK activators on TNF-alpha-induced cardiomyocyte apoptosis. Incubation of myocytes with TNF-alpha for 8 h has increased caspase-3 activation and apoptotic cell death, an effect that was abrogated by DEX and MET. The beneficial effect of DEX and MET was associated with stimulation of AMPK, which led to a rapid and sustained increase in Bad phosphorylation. This event reduced the interaction between Bad and Bcl-xL, limiting cytochrome c release and caspase-3 activation. Addition of Compound C to inhibit AMPK reduced Bad phosphorylation and prevented the beneficial effects of AMPK against TNF-alpha-induced cytotoxicity.Our data demonstrate that although DEX and MET are used as anti-inflammatory agents or insulin sensitizers, respectively, their common property to phosphorylate AMPK promotes cardiomyocyte cell survival through its regulation of Bad and the mitochondrial apoptotic mechanism.