title: 7-Ketocholesterol inhibits isocitrate dehydrogenase 2 expression and impairs endothelial function via microRNA-144.
abstract: Oxysterol is associated with the induction of endothelial oxidative stress and impaired endothelial function. Mitochondria play a central role in oxidative energy metabolism and the maintenance of proper redox status. The purpose of this study was to determine the effects and mechanisms of 7-ketocholesterol (7-KC) on isocitrate dehydrogenase 2 (IDH2) and its impact on endothelial function in both human aortic endothelial cells (HAECs) and C57BL/6J mice. HAECs treated with 7-KC showed significant reductions of IDH2 mRNA and protein levels and enzyme activity, leading to decreased NADPH concentration and an increased ratio of reduced-to-oxidized glutathione in the mitochondria. 7-KC induced the expression of a specific microRNA, miR-144, which in turn targets and downregulates IDH2. In silico analysis predicted that miR-144 could bind to the 3'-untranslated region of IDH2 mRNA. Overexpression of miR-144 decreased the expression of IDH2 and the levels of NADPH. A complementary finding is that a miR-144 inhibitor increased the mRNA and protein expression levels of IDH2. Furthermore, miR-144 level was elevated in HAECs in response to 7-KC. Anti-Ago1/2 immunoprecipitation coupled with a real-time polymerase chain reaction assay revealed that 7-KC increased the functional targeting of miR-144/IDH2 mRNA in HAECs. Infusion of 7-KC in vivo decreased vascular IDH2 expression and impaired vascular reactivity via miR-144. 7-KC controls miR-144 expression, which in turn decreases IDH2 expression and attenuates NO bioavailability to impair endothelial homeostasis. The newly identified 7-KC-miR-144-IDH2 pathway may contribute to atherosclerosis progression and provides new insight into 7-KC function and microRNA biology in cardiovascular disease.
authors.affiliation: Department of Physiology, School of Basic Science, Guangzhou Medical University, Guangzhou, Guangdong Province, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Fu
authors.affiliation: Guangdong Provincial Key Laboratory of Food, Nutrition, and Health, School of Public Health, Sun Yat-sen University (Northern Campus), Guangzhou, Guangdong Province, China; Department of Nutrition, School of Public Health, Sun Yat-sen University (Northern Campus), Guangzhou, Guangdong Province, China.
authors.forename: Xiuwei
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Physiology, School of Basic Science, Guangzhou Medical University, Guangzhou, Guangdong Province, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Physiology, School of Basic Science, Guangzhou Medical University, Guangzhou, Guangdong Province, China.
authors.forename: Weiyu
authors.initials: W
authors.lastname: Chen
authors.affiliation: Guangdong Provincial Key Laboratory of Food, Nutrition, and Health, School of Public Health, Sun Yat-sen University (Northern Campus), Guangzhou, Guangdong Province, China; Department of Nutrition, School of Public Health, Sun Yat-sen University (Northern Campus), Guangzhou, Guangdong Province, China. Electronic address: xiamin@mail.sysu.edu.cn.
authors.forename: Min
authors.initials: M
authors.lastname: Xia
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D001011:Aorta / Q000378:metabolism* / Q000473:pathology; D060565:Argonaute Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D050197:Atherosclerosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002417:Cattle; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D039642:Eukaryotic Initiation Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D007521:Isocitrate Dehydrogenase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D007653:Ketocholesterols / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D012333:RNA, Messenger / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D020413:3' Untranslated Regions; C115848:AGO1 protein, human; C466422:AGO2 protein, human; D060565:Argonaute Proteins; D039642:Eukaryotic Initiation Factors; D007653:Ketocholesterols; C554293:MIRN144 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; D009249:NADP; C538784:IDH2 protein, human; D007521:Isocitrate Dehydrogenase; D005978:Glutathione; C003001:7-ketocholesterol
keywords: 7-KC; Endothelial function; IDH2; Oxysterol; miRNA