Department of Cardiology, Northern Jiangsu People's Hospital, Yangzhou, Jiangsu, China.
Graduate School of Dalian Medical University, Dalian, Liaoning, China.
J Cardiovasc Pharmacol. 2021 May 1;77(5):586-593. doi: 10.1097/FJC.0000000000000991.
As a biomarker for heart failure, miR-129-5p is abnormally expressed during myocardial I/R, but its specific functions and mechanisms remain largely unclear. Thus, this study explored the roles and possible mechanisms of miR-129-5p in hypoxia/reoxygenation (H/R)-insulted H9c2 cardiac myoblasts. After H/R insult, miR-129-5p expression levels were decreased, along with reduced cell viability and enhanced lactate dehydrogenase release in H9c2 cells. Overexpression of miR-129-5p through transfection of miR-129-5p mimics effectively improved cell viability and reduced lactate dehydrogenase release in H9c2 cells exposed to H/R, along with decreased apoptosis and caspase-3 activities. Moreover, miR-129-5p mimics inhibited reactive oxygen species production and upsurged superoxide dismutase activity in H9c2 cells exposed to H/R, and suppressed H/R-caused massive release of proinflammatory cytokines TNF-α and IL-1β. TRPM7 was identified as the target of miR-129-5p and was negatively regulated by miR-129-5p. TRPM7 overexpression counteracted the antagonistic effect of miR-129-5p on H/R-induced increase in intracellular calcium levels. TRPM7 overexpression also abolished miR-129-5p-induced elevation on cell viability and reduction on apoptosis as well as attenuated miR-129-5p-induced inhibition on reactive oxygen species and IL-1β production. Besides, H/R-induced NLRP3 inflammasome activation was inhibited by miR-129-5p mimic but reactivated by TRPM7. In conclusion, miR-129-5p alleviates H/R injury of H9c2 cardiomyocytes by targeting TRPM7 and inhibiting NLRP3 inflammasome activation, suggesting that miR-129-5p and TRPM7 may be potential therapeutic targets for myocardial I/R injury.
作为心力衰竭的生物标志物，miR-129-5p 在心肌 I/R 期间异常表达，但它的具体功能和机制在很大程度上仍不清楚。因此，本研究探讨了 miR-129-5p 在缺氧/复氧（H/R）损伤的 H9c2 心肌细胞中的作用和可能的机制。H/R 损伤后，miR-129-5p 的表达水平降低，同时 H9c2 细胞的活力降低，乳酸脱氢酶释放增加。通过转染 miR-129-5p 模拟物过表达 miR-129-5p 可有效提高 H/R 暴露的 H9c2 细胞的活力并降低乳酸脱氢酶释放，同时减少细胞凋亡和 caspase-3 活性。此外，miR-129-5p 模拟物抑制 H/R 引起的 H9c2 细胞中活性氧的产生和超氧化物歧化酶活性的增加，并抑制 H/R 引起的促炎细胞因子 TNF-α和 IL-1β的大量释放。TRPM7 被鉴定为 miR-129-5p 的靶标，并受 miR-129-5p 的负调控。TRPM7 过表达拮抗了 miR-129-5p 对 H/R 诱导的细胞内钙水平升高的拮抗作用。TRPM7 过表达还消除了 miR-129-5p 诱导的细胞活力升高和凋亡减少，并减弱了 miR-129-5p 对活性氧和 IL-1β产生的抑制作用。此外，miR-129-5p 模拟物抑制了 H/R 诱导的 NLRP3 炎性体激活，但 TRPM7 可使其重新激活。总之，miR-129-5p 通过靶向 TRPM7 抑制 NLRP3 炎性体激活来减轻 H9c2 心肌细胞的 H/R 损伤，提示 miR-129-5p 和 TRPM7 可能是心肌 I/R 损伤的潜在治疗靶点。
