CD226 deficiency promotes glutaminolysis and alleviates mitochondria damage in vascular endothelial cells under hemorrhagic shock
CD226 deficiency promotes glutaminolysis and alleviates mitochondria damage in vascular endothelial cells under hemorrhagic shock
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CD226缺乏促进谷氨酰胺分解并减轻失血性休克下血管内皮细胞的线粒体损伤
DOI：
10.1096/fj.202101134r
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发表时间：
2021-11-01
期刊：
影响因子：
4.8
通讯作者：
Zhuang，Ran
中科院分区：
文献类型：
--
作者：
Zhou，Shangxun;Xie，Jiangang;Zhuang，Ran
出血性休克（HS）在临床紧急情况中很常见，每年在全球导致数百万人死亡。CD 226是一种共刺激粘附分子，在免疫细胞和内皮细胞（EC）上表达，以调节其代谢活性和功能。由于HS后发生内皮功能障碍，研究了CD 226在血管EC代谢中的作用。采用CD 226 fl/fl Tekcre小鼠以实现CD 226的血管EC特异性敲除，并进行HS建模。通过液相色谱-质谱分析评价关键中间代谢物的血清水平。以人脐静脉内皮细胞（HUVEC）为材料，体外研究缺氧条件下CD 226的作用。海马分析评估了细胞糖酵解和线粒体生物能量学。结果表明，血管内皮细胞中的CD 226缺陷减轻了HS诱导的小鼠肠道损伤和炎症反应。动物研究表明，当HS后EC中的CD 226被敲除时，能量代谢得到改善，如谷氨酰胺-谷氨酸代谢增强和乳酸水平降低所证明的。在缺氧条件下，HS和HUVEC后小鼠血管EC中Glut-1上调，同时CD 226降低。此外，CD 226敲低的HUVECs在缺氧条件下表现出减轻线粒体损伤和早期凋亡，而CD 226过表达则表现出相反的效果。Seahorse分析显示，下调的CD 226显著增加缺氧条件下HUVECs的线粒体ATP产生和葡萄糖摄取。此外，Erk/PHD 2信号通路介导的HIF-1α/Glut-1和HIF-2α/ASCT 2通路参与了CD 226对缺氧后HUVEC脱氨的调节。因此，CD 226缺陷促进缺血或缺氧应激下血管EC的旁路能量供应，以改善应激介导的代谢紊乱。
Hemorrhagic shock (HS) is common in clinical emergencies, leading to millions of deaths each year globally. CD226 is a costimulatory adhesion molecule expressed on both immune cells and endothelial cells (ECs) to regulate their metabolic activity and function. As endothelial dysfunction occurs after HS, the roles CD226 plays in vascular EC metabolism were investigated. CD226fl/fl Tekcre mice were adopted to achieve vascular EC‐specific knockout of CD226, and subjected to HS modelling. Serum levels of crucial intermediate metabolites were evaluated through liquid chromatography‐mass spectrometry analysis. Human umbilical vein ECs (HUVECs) were used to study the effects of CD226 under hypoxia in vitro. Seahorse analysis evaluated the cellular glycolysis and mitochondria bioenergetics. Results showed that CD226 deficiency in vascular ECs alleviated HS‐induced intestinal damage and inflammatory response in mice. Animal studies indicated an improved energy metabolism when CD226 was knocked out in ECs after HS, as evidenced by enhanced glutamine‐glutamate metabolism and decreased lactic acid levels. Glut‐1 was upregulated in mouse vascular ECs after HS and HUVECs under hypoxia, combined with decreased CD226. Moreover, HUVECs with CD226 knockdown exhibited relieved mitochondrial damage and early apoptosis under hypoxia, whereas CD226 overexpression showed opposite effects. Seahorse analysis showed that downregulated CD226 significantly increased mitochondrial ATP production and glucose uptake in HUVECs under hypoxia. Additionally, Erk/PHD2 signaling‐mediated HIF‐1α/Glut‐1 and HIF‐2α/ASCT2 pathways were involved in CD226 regulation on HUVEC glutaminolysis after hypoxia. Hence, CD226 deficiency promotes bypass energy supply to vascular ECs under ischemic or hypoxic stress, to ameliorate the stress‐mediated metabolic disturbance.