蛋白激酶A（PKA）与蛋白激酶B（Akt）之间的相互作用可保护内皮细胞在晚期缺血预处理中免于凋亡。

Cross-talk between PKA and Akt protects endothelial cells from apoptosis in the late ischemic preconditioning.

作者信息

Bellis Alessandro, Castaldo Diletta, Trimarco Valentina, Monti Maria Gaia, Chivasso Pierpaolo, Sadoshima Junichi, Trimarco Bruno, Morisco Carmine

机构信息

Dipartimento di Medicina Clinica, Scienze Cardiovascolari ed Immunologiche. Università FEDERICO II, Napoli, Via S. Pansini n.5, 80131 Napoli, Italy.

出版信息

Arterioscler Thromb Vasc Biol. 2009 Aug;29(8):1207-12. doi: 10.1161/ATVBAHA.109.184135. Epub 2009 May 21.

DOI:10.1161/ATVBAHA.109.184135

PMID:19461052

Abstract

OBJECTIVE

The aim of this study was to explore the molecular mechanisms involved in late preconditioning-induced cell protection in endothelial cells.

METHODS AND RESULTS

Preconditioning (PC) was induced by exposing bovine aortic endothelial cells (BAECs) to 3 cycles of 15 minutes of hypoxia followed by 15 minutes of reoxygenation. A 12-hour period of hypoxia induced cell death in 60% of BAECs (48+/-5% apoptosis, 12+/-4% necrosis). Early and late PC decreased hypoxia-induced apoptotic (25+/-5% and 28+/-4%, respectively) and necrotic (6+/-3%, and 8+/-2%, respectively) cell death. Consistently, hypoxia-induced caspase-3 cleavage was reduced by PC. Pretreatment with H89 (protein kinase A [PKA] inhibitor), LY294002 (phosphatidyl-inositol-3-kinase [PI3K] inhibitor), and N-acetyl-cysteine (antioxidant) abrogated late PC-induced cell protection, whereas inhibition of protein kinase C by Go6983, and of nitric oxide synthesis by L-NAME,1400W and bovine eNOS siRNA did not. In addition, in early and late PC, PKA physically interacted with the phosphorylated form of Akt, suggesting that PKA is required for Akt phosphorylation. Expression of PKA and Akt dominant negative mutants inhibited ischemic late PC-induced protection, indicating that these kinases play a key role in late PC-mediated cell protection.

CONCLUSIONS

Late ischemic PC protects BAECs against hypoxia through PKA- and PI3K-dependent activation of Akt.

摘要

目的

本研究旨在探索晚期预处理诱导内皮细胞保护作用的分子机制。

方法与结果

通过将牛主动脉内皮细胞（BAECs）暴露于3个周期的15分钟缺氧随后15分钟复氧来诱导预处理（PC）。12小时的缺氧诱导60%的BAECs发生细胞死亡（48±5%凋亡，12±4%坏死）。早期和晚期PC均降低了缺氧诱导的凋亡（分别为25±5%和28±4%）和坏死（分别为6±3%和8±2%）性细胞死亡。同样，PC减少了缺氧诱导的半胱天冬酶-3切割。用H89（蛋白激酶A [PKA]抑制剂）、LY294002（磷脂酰肌醇-3-激酶[PI3K]抑制剂）和N-乙酰半胱氨酸（抗氧化剂）预处理可消除晚期PC诱导的细胞保护作用，而Go6983对蛋白激酶C的抑制以及L-NAME、1400W和牛内皮型一氧化氮合酶小干扰RNA对一氧化氮合成的抑制则没有这种作用。此外，在早期和晚期PC中，PKA与磷酸化形式的Akt发生物理相互作用，提示PKA是Akt磷酸化所必需的。PKA和Akt显性负突变体的表达抑制了缺血晚期PC诱导的保护作用，表明这些激酶在晚期PC介导的细胞保护中起关键作用。