武汉云克隆科技股份有限公司

Abstract:

Atherosclerosis (AS) is an inflammatory disease linked to endothelial dysfunction. Melatonin is reported to possess substantial anti-inflammatory properties, which has proven to be effective in AS. Emerging literature suggests that pyroptosis plays a critical role during AS progression. However, whether pyroptosis contributes to endothelial dysfunction and the underlying molecular mechanisms remained unexploited. This study was designed to investigate the antipyroptotic effects of melatonin in atherosclerotic endothelium and to elucidate the potential mechanisms. In this study, high-fat diet (HFD)-treated ApoE-/- mice were used as an atherosclerotic animal model. We found intragastric administration of melatonin for 12 weeks markedly reduced the atherosclerotic plaque in aorta. Meanwhile, melatonin also attenuated the expression of pyroptosis-related genes, including NLRP3, ASC, cleaved caspase1, NF-κB/GSDMD, GSDMD N-termini, IL-1β, and IL-18 in aortic endothelium of melatonin-treated animals. Consistent antipyroptotic effects were also observed in ox-LDL-treated human aortic endothelial cells (HAECs). We found that lncRNA MEG3 enhanced pyroptosis in HAECs. Moreover, MEG3 acted as an endogenous sponge by sequence complementarity to suppress the function of miR-223 and to increase NLRP3 expression and enhance endothelial cell pyroptosis. Furthermore, knockdown of miR-223 blocked the antipyroptotic actions of melatonin in ox-LDL-treated HAECs. Together, our results suggest that melatonin prevents endothelial cell pyroptosis via MEG3/miR-223/NLRP3 axis in atherosclerosis, and therefore, melatonin replacement might be considered a new strategy for protecting endothelium against pyroptosis, thereby for the treatment of atherosclerosis associated with pyroptosis.

摘要：动脉粥样硬化(AS)是一种与内皮功能障碍相关的炎症性疾病。据报道褪黑素具有很强的抗炎作用，可以有效治疗动脉粥样硬化。最新文献表明，细胞炎症坏死在动脉粥样硬化疾病发展机制中起关键作用。然而，细胞炎症坏死是否会导致内皮功能障碍以及其潜在的分子机制仍未知晓。本研究旨在研究褪黑素对动脉粥样硬化内皮细胞的抗炎作用并阐明潜在机制。选用高脂饮食(HFD)的ApoE-/-小鼠作为动脉粥样硬化动物模型。褪黑素给药12周后，动脉粥样硬化斑块明显减少，主动脉内皮细胞上相关基因的表达受到抑制，包括NLRP3、ASC、cleaved caspase1、NF-κB/GSDMD、GSDMD N-termini、IL-1β和IL-18。经ox-LDL处理的人主动脉内皮细胞（HAECs）中也观察到抗凋亡效应。研究发现lncRNA MEG3促进了人主动脉内皮细胞炎症坏死，MEG 3通过序列互补作为内源性海绵，抑制miR-223的功能，增加NLRP 3的表达，促进内皮细胞炎症坏死。此外，miR-223的基因敲除阻断了褪黑素对ox-LDL处理的人主动脉内皮细胞中的抗炎作用。实验结果显示褪黑素通过调控RNA MEG3/miR-223/NLRP3抑制内皮细胞炎症坏死，因此褪黑素替代物可能成为一种抑制内皮细胞炎症坏死的新策略，从而治疗与细胞炎症坏死相关的动脉粥样硬化疾病。

使用试剂原文信息：Serum contents of interleukin-1β (IL-1β; BOSTER, Wuhan, China) and IL-18 (USCN, Wuhan, China) were determined using the ELISA kits following the manufacturer’s instructions.