C-reactive protein aggravates myocardial ischemia/reperfusion injury through activation of extracellular-signal-regulated kinase 1/2

当组织被重新酒跟随局部缺血的延长经期时， BackgroundIschemia/reperfusion 损害(IRI ) 是发生的煽动性的回答。几研究显示了那 C 反应的蛋白质(CRP ) 可能在导致 IRI 起一个重要作用。然而，心肌的 IRI 和内在的机制上的 CRP 的效果充分没被阐明。试图调查在 CRP 和心肌的 IRI 和内在的 mechanisms.MethodsWe 之间的协会的这研究在新生的 Sprague-Dawley 老鼠 cardiomyocytes 用氧葡萄糖 deprivation/ 氧化(OGD/R ) 模仿了 ischemia/reperfusion；灌注损害与到一小时灌注跟随的葡萄糖和浆液剥夺到三小时组织缺氧被导致。房间生存能力与山试金被测试，并且 cardiomyocyte 损坏被评估由喂奶脱氢酶(LDH ) 漏。Mitochondrial 膜潜力用 tetramethylrhodamine 乙醇酉旨(TMRE ) 被测量， mitochondrial 渗透转变毛孔(mPTP ) 洞用 calcein/AM 被测量；TMRE 和 caocein/AM 与扫描共焦的显微镜学的激光被设想。另外，我们学习了与简单 OGD/R 组一起经由西方的污点 analysis.ResultsCompared 位于 调停CRP 的 ischemia/reperfusion 损害下面的发信号的小径，吗在有 10 的干预以后?????????传???????????圠卍????????????椠'諗珮I???????????????????？？

Background Ischemia/reperfusion injury （IRI） is an inflammatory response that occurs when tissue is reperfused following a prolonged period of ischemia. Several studies have indicated that C-reactive protein （CRP） might play an important role in inducing IRI. However, the effects of CRP on myocardial IRI and the underlying mechanisms have not been fully elucidated. This study aimed to investigate the association between CRP and myocardial IRI and the underlying mechanisms. Methods We simulated ischemia/reperfusion using oxygen-glucose deprivation/ reoxygenation （OGD/R） in neonatal Sprague-Dawley rat cardiomyocytes; reperfusion injury was induced by three hours of hypoxia with glucose and serum deprivation followed by one hour of reperfusion. Cell viability was tested with MTS assays, and cardiomyocyte damage was evaluated by lactate dehydrogenase （LDH） leakage. Mitochondrial membrane potential was measured using tetramethylrhodamine ethyl ester （TMRE） and mitochondrial permeability transition pore （mPTP） opening was measured using calcein/AM; both TMRE and caocein/AM were visualized with laser scanning confocal microscopy. In addition, we studied the signaling pathways underlying CRP-mediated ischemia/reperfusion injury via Western blot analysis. Results Compared with the simple OGD/R group, after intervention with 10 pg/mL CRP, cell viability decreased markedly （82.36 % ± 6.18% vs. 64.84% ± 4.06%, P = 0.0007）, and the LDH leakage significantly increased （145.3 U/L ± 16.06 U/L vs. 208.2 U/L ± 19.23 U/L, P = 0.0122）. CRP also activated mPTP opening and reduced mitochondrial membrane potential during myocardial ischemia/reperfusion. Pretreatment with 1 pM atorvastatin （Ator） before CRP intervention protected cardiomyocytes from IRI. Mitochondrial KATP channel opener diazoxide and mPTP inhibitor cyclosporin A also offset the effects of CRP in this process. The level of phosphorylated extracellular-signal-regulated kinase （ERK） 1/2 was significantly higher after pre-treatment with CRP compared with the OGD/R group （170.4% ± 3.00% v.v. 93.53% ± 1.94%, P 〈 0.0001）. Western blot analysis revealed that Akt expression was markedly activated （184.2% ± 6.96% vs. 122.7% ± 5.30%, P = 0.0003） and ERK 1/2 phosphorylation significantly reduced after co-treatment with Ator and CRP compared with the level after CRP pretreatment alone. Conclusions Our results suggested that CRP directly aggravates myocardial IRI in myocardial cells and that this effect is primarily mediated by inhibiting mitochondrial ATP- sensitive potassium （mitoKATp） channels and promoting mPTP opening. Ator counteracts these effects and can reduce CRP-induced IRI. One of the mechanisms of CRP-induced IRI may be related to the sustained activation of the ERK signaling pathway.