Trimethylamine N-oxide (TMAO), a metabolite produced by intestinal flora, is recognized as an independent risk factor for atherosclerosis and atherosclerotic cardiovascular diseases. However, the underlying mechanism remains poorly understood. Here, we showed that dietary TMAO supplementation accelerates atherosclerosis in ApoE-/- mice. Pyroptosis and the expression of phospholipid-modifying enzyme MBOAT2 were increased in endothelial cells within atherosclerotic lesions. Genetic upregulation of MBOAT2 via adeno-associated virus with endothelium-specific promoter results in increased atherosclerotic lesions in ApoE-/- mice. Mechanistically, the overexpression of MBOAT2 disrupted glycerophospholipid metabolism and induced endothelial cell pyroptosis in an Endoplasmic reticulum stress-dependent manner. These data reveal that TMAO promotes endothelial cell pyroptosis and the progression of atherosclerotic lesions through the upregulation of MBOAT2, indicating that MBOAT2 is a promising therapeutic target for atherosclerosis.

Atherosclerosis is a progressive inflammatory disease within the large and medium arteries. SUCNR1(Succinate receptor 1) has been reported to regulate the inflammatory response in cardiovascular diseases, but how it works in atherosclerosis remains unclear. In this study, we observed that SUCNR1 is upregulated in endothelial cells within human atherosclerotic lesions. The deletion of SUCNR1 in vascular endothelial cells can mitigate the progression of atherosclerotic lesions in high-fat diet ApoE-/- mice. The overexpression or activation of SUCNR1 intensified endoplasmic reticulum stress and mitochondria-endoplasmic reticulum interactions. Moreover, SUCNR1 exacerbated mitochondrial injury, mtDNA leakage, and the activation of cGAS-STING signaling. Elevated mitochondrial damage, ER-mitochondrial interactions, and inflammation induced by SUCNR1 activation were blocked by the endoplasmic reticulum stress inhibitor. Collectively, these findings suggest that SUCNR1 promotes atherosclerosis through endoplasmic reticulum stress signaling mediated ER-mitochondrial crosstalk and its downstream cGAS-STING pathway. Our results provide new insights into the mechanism of SUCNR1 in atherosclerosis and inhibiting endoplasmic reticulum stress signaling may provide a promising strategy to prevent and treat atherosclerosis.

Vascular endothelial cell (VEC) inflammation induced by low shear stress plays key roles in the initiation and progression of atherosclerosis (As). Pyroptosis is a form of inflammatory programmed cell death that is critical for As. However, the effect of low shear stress on VEC pyroptosis and the underlying mechanisms were not clear. Here we show that low shear stress promoted VEC pyroptosis and reduced the expression of Ten-Eleven Translocation 2 (TET2) methylcytosine dioxygenase. Loss of TET2 resulted in the upregulation of the expression and activity of mitochondrial respiratory complex II subunit succinate dehydrogenase B (SDHB) by decreasing the recruitment of histone deacetylase 2, independent of DNA demethylation modification. The overexpression of SDHB mediated mitochondrial injury and increased the production of reactive oxygen species (ROS). The administration of ROS scavenger NAC alleviated VEC pyroptosis induced by SDHB overexpression and TET2 shRNA. These findings show that low shear stress induced endothelial cell pyroptosis through the TET2/SDHB/ROS pathway and offer new insights into As.

目的 探讨miR-320对人脐静脉内皮细胞(HUVEC)内皮间质转化(EndMT)的影响及其调控机制.方法 用miR-320 mimics或miR-320 inhibitor处理HUVEC.Western blot检测内皮细胞标记物血小板内皮细胞黏附分子1(CD31)、血管内皮钙黏蛋白(VE-Cadherin)及间质细胞标记物α平滑肌肌动蛋白(α-SMA)、波形蛋白(Vim-entin)的表达;划痕实验、Transwell实验检测miR-320对HUVEC迁移的影响;罗丹明鬼笔环肽染色检测miR-320对HUVEC细胞骨架的影响;噻唑蓝法检测细胞增殖;流式细胞仪检测细胞周期;Western blot检测miR-320对SRY相关高迁移率族蛋白4(SOX4)表达的影响.结果 miR-320 mimics上调HUVEC的VE-Cadherin、CD31表达,下调Vi-mentin、α-SMA表达;miR-320 mimics使HUVEC细胞骨架微丝变细,应力纤维减少,细胞迁移能力减弱,但增殖能力无明显改变.miR-320 inhibitor 下调HUVEC 的VE-Cadherin、CD31 表达,上调Vimentin、α-SMA表达;miR-320 inhib-itor使HUVEC微丝增粗,应力纤维增多,细胞迁移能力增强.miR-320 mimics下调SOX4的表达,miR-320 inhibitor上调SOX4的表达.结论 miR-320通过下调SOX4的表达抑制HUVEC的EndMT.

Trimethylamine N-oxide (TMAO) is produced from the phosphatidylcholine metabolism of gut flora and acts as a risk factor of cardiovascular disease. However, the underlying mechanisms for its proatherogenic action remain unclear. This study aimed to observe the effect of TMAO on endothelial cell pyroptosis and explore the underlying mechanisms. Our results showed that TMAO promoted the progression of atherosclerotic lesions in apolipoprotein E-deficient (apoE(-/-)) mice fed a high-fat diet. Pyroptosis and succinate dehydrogenase complex subunit B (SDHB) upregulation were detected in the vascular endothelial cells of apoE(-/-) mice and in cultured human umbilical vein endothelial cells (HUVECs) treated with TMAO. Overexpression of SDHB in HUVECs enhanced pyroptosis and impaired mitochondria and high reactive oxygen species (ROS) level. Pyroptosis in the SDHB overexpression of endothelial cells was inhibited by the ROS scavenger NAC. In summary, TMAO promotes vascular endothelial cell pyroptosis via ROS induced through SDHB upregulation, thereby contributing to the progression of atherosclerotic lesions.

MiRNA为小分子非编码RNA,通过与靶基因的相互作用调节靶基因的表达,参与调控细胞的多个生物学过程.本文综述了miRNA与线粒体生物合成、线粒体动力学、线粒体能量代谢、线粒体钙稳态、线粒体自噬间的关系及其调节机制,阐述了microRNA调节线粒体功能的研究进展.

Mitochondria are highly dynamic organelles beyond powerhouses of a cell. These components also play important roles in cell homeostasis by regulating cell function and phenotypic modulation. Atherosclerosis is the leading cause of morbidity and mortality in developed and developing countries. Mitochondrial dysfunction has been increasingly associated with the initiation and progression of atherosclerosis by elevating the production of reactive oxygen species and mitochondrial oxidative stress damage, mitochondrial dynamics dysfunction, and energy supply. In this review, we describe the progression of the link between mitochondrial dysfunction and atherosclerosis and its potential regulation mechanisms.

Atherosclerosis is a major disease that seriously harms human health and is known as the "number one killer" in developed countries and the leading cause of death worldwide. Glutamine is the most abundant nonessential amino acid in the human blood that has multifaceted effects on the body. Recent studies showed that glutamine is negatively corrected with the progression of atherosclerotic lesions. In this review, we focused on the relationship of glutamine with macrophage polarization, nitrification stress, oxidative stress injury, myocardial ischemia-reperfusion injury, and therapeutic angiogenesis to review its roles in atherosclerotic cardiovascular disease.

能量代谢即细胞对供能物质的利用和ATP生成的过程.动脉粥样硬化(atherosclerosis,As)为慢性炎症性病理过程,近年来的研究表明,能量代谢异常影响内皮细胞功能、平滑肌细胞增殖、巨噬细胞的极化等生物学过程,进一步影响As病变进程.深入探讨能量代谢异常与As病变之间的关系及其调控机制,将可能为As的有效防治提供新的靶点和治疗策略.