Pei Haifeng, Song Xiaofeng, Peng Chengfei, Tan Yan, Li Ying, Li Xia, Ma Shuangtao, Wang Qiang, Huang Rong, Yang Dachun, Li De, Gao Erhe, Yang Yongjian
Department of Cardiology, Chengdu Military General Hospital, Chengdu 610083, China.
Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang 110016, China.
Free Radic Biol Med. 2015 May;82:114-21. doi: 10.1016/j.freeradbiomed.2015.02.002. Epub 2015 Feb 11.
TNF-α inhibitor reportedly protects against myocardial ischemia/reperfusion (MI/R) injury. It can also increase Notch1 expression in inflammatory bowel disease, revealing the regulation of Notch1 signaling by TNF-α inhibitor. However, the interaction between TNF-α inhibitor and Notch1 signaling in MI/R remains unclear. This study aimed to determine the involvement of TNF-α inhibitor with Notch1 in MI/R and delineate the related mechanism. Notch1-specific small interfering RNA (20 μg) or Jagged1 (a Notch ligand, 12 μg) was delivered through intramyocardial injection. Forty-eight hours after injection, mice received 30 min of myocardial ischemia followed by 3 h (for cell apoptosis and oxidative/nitrative stress) or 24h (for infarct size and cardiac function) of reperfusion. Ten minutes before reperfusion, mice randomly received an intraperitoneal injection of vehicle, etanercept, diphenyleneiodonium, 1400W, or EUK134. Finally, downregulation of Notch1 significantly reversed the alleviation of MI/R injury induced by etanercept, as evidenced by enlarged myocardial infarct size, suppressed cardiac function, and increased myocardial apoptosis. Moreover, Notch1 blockade increased the expression of inducible NO synthase (iNOS) and gp(91)(phox), enhanced NO and superoxide production, and accelerated their cytotoxic reaction product, peroxynitrite. Furthermore, NADPH inhibition with diphenyleneiodonium or iNOS suppression with 1400W mitigated the aggravation of MI/R injury induced by Notch1 downregulation in mice treated with etanercept. Additionally, either Notch1 activation with Jagged1 or peroxynitrite decomposition with EUK134 reduced nitrotyrosine content and attenuated MI/R injury. These data indicate that MI/R injury can be attenuated by TNF-α inhibitor, partly via Notch1 signaling-mediated suppression of oxidative/nitrative stress.
据报道，肿瘤坏死因子-α（TNF-α）抑制剂可预防心肌缺血/再灌注（MI/R）损伤。它还能增加炎症性肠病中Notch1的表达，揭示了TNF-α抑制剂对Notch1信号通路的调控作用。然而，TNF-α抑制剂与Notch1信号通路在MI/R中的相互作用仍不清楚。本研究旨在确定TNF-α抑制剂与Notch1在MI/R中的关系，并阐明相关机制。通过心肌内注射给予Notch1特异性小干扰RNA（20μg）或Jagged1（一种Notch配体，12μg）。注射后48小时，小鼠经历30分钟的心肌缺血，随后进行3小时（用于细胞凋亡和氧化/硝化应激）或24小时（用于梗死面积和心脏功能）的再灌注。在再灌注前10分钟，小鼠随机接受腹腔注射溶媒、依那西普、二苯碘鎓、1400W或EUK134。最后，Notch1的下调显著逆转了依那西普诱导的MI/R损伤的减轻，表现为心肌梗死面积增大、心脏功能受抑和心肌细胞凋亡增加。此外，Notch1阻断增加了诱导型一氧化氮合酶（iNOS）和gp(91)(phox)的表达，增强了一氧化氮和超氧阴离子的产生，并加速了它们的细胞毒性反应产物过氧亚硝酸盐的生成。此外，用二苯碘鎓抑制烟酰胺腺嘌呤二核苷酸磷酸（NADPH）或用1400W抑制iNOS减轻了依那西普处理的小鼠中Notch1下调所诱导的MI/R损伤的加重。此外，用Jagged1激活Notch1或用EUK134分解过氧亚硝酸盐均可降低硝基酪氨酸含量并减轻MI/R损伤。这些数据表明，TNF-α抑制剂可减轻MI/R损伤，部分是通过Notch1信号通路介导的对氧化/硝化应激的抑制作用。
