title: MicroRNA-126 suppresses inflammation in endothelial cells under hyperglycemic condition by targeting HMGB1.
abstract: MicroRNA-126(miR-126) targets involved in inflammation need to be identified. In this study, we aim to investigate whether high-mobility group box 1(HMGB1), an inflammation-related gene, is the target of miR-126 in diabetic vascular endothelium. The diabetic apoE-/-mice model, a classical diabetic atherosclerosis model, was established. The aorta of diabetic apoE-/-mice showed decrease of miR-126 and elevation of HMGB1 and inflammation. Next, we employed several in vitro experiments to address the role of miRNA-126 on the regulation of HMGB1 in endothelial cells under hyperglycemic and inflammatory conditions. Manipulation of miRNA levels in human umbilical vein endothelial cells (HUVECs) was achieved by transfecting cells with miR-126 mimic and antagomir. Overexpression of miR-126 could decrease the expression of downstream components of HMGB1 including TNF-α, ROS, and NADPH oxidase activity in HUVECs under hyperglycemic condition. Nevertheless, such phenomenon was completely reversed by miR-126 antagomir. The expression of HMGB1 protein rather than HMGB1 mRNA was down-regulated after transfection with miR-126 mimic, which indicated the modulation of HMGB1 mediated by miR-126 was at the posttranslational level. Luciferase reporter assay confirmed the 3'-UTR of HMGB1 gene was a direct target of miR-126. Western blot analysis also indicated that overexpression of miR-126 contributed to the elevation of p-eNOS, eNOS and p-AKT expressions, respectively. In summary, our findings suggest that miR-126 may suppress inflammation and ROS production in endothelial cells treated by high glucose through modulating the expression of HMGB1. Our study provides a novel pathogenic link between dysregulated miRNA expression and inflammation in diabetic vascular endothelium.
authors.affiliation: Laboratory of Molecular Biology and Department of Biochemistry, Anhui Medical University, Hefei, China; Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.
authors.forename: Song-Tao
authors.initials: ST
authors.lastname: Tang
authors.affiliation: Department of Ophthalmology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Critical Care Medicine, Affiliated Provincial Hospital of Anhui Medical University, Hefei, China.
authors.forename: Min
authors.initials: M
authors.lastname: Shao
authors.affiliation: Laboratory of Molecular Biology and Department of Biochemistry, Anhui Medical University, Hefei, China. Electronic address: wangyuan@ahmu.edu.cn.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Laboratory of Molecular Biology and Department of Biochemistry, Anhui Medical University, Hefei, China. Electronic address: aydzhq@126.com.
authors.forename: Hua-Qing
authors.initials: HQ
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics*; D050197:Atherosclerosis / Q000235:genetics / Q000473:pathology; D003921:Diabetes Mellitus, Experimental / Q000235:genetics / Q000473:pathology; D015536:Down-Regulation / Q000235:genetics; D004730:Endothelium, Vascular / Q000473:pathology; D005947:Glucose / Q000378:metabolism; D024243:HMGB1 Protein / Q000235:genetics*; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D006943:Hyperglycemia / Q000235:genetics; D007249:Inflammation / Q000235:genetics* / Q000473:pathology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D035683:MicroRNAs / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014162:Transfection
chemical_list: D001057:Apolipoproteins E; D024243:HMGB1 Protein; C527111:MIRN126 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D005947:Glucose
keywords: Atherosclerosis; Diabetes; High-mobility group box 1; Inflammation; MiR-126