title: The miR-322-TRAF3 circuit mediates the pro-apoptotic effect of high glucose on neural stem cells.
abstract: Maternal diabetes increases the risk of neural tube defects (NTDs), and caspase-dependent apoptosis and gene dysregulation are implicated in this disease process. This study investigates the role of miR-322 and its putative target gene, TNF receptor-associated factor 3 (TRAF3), in high glucose-induced apoptosis. miR-322 and TRAF3 expression were assessed in embryos of nondiabetic and diabetic dams, and in neural stem cells under high glucose conditions. Maternal diabetes in vivo and high glucose in vitro significantly down-regulated miR-322 and up-regulated TRAF3 protein expression. Overexpression of the antioxidant enzyme, superoxide dismutase 1 (SOD1), or treatment with the SOD1 mimetic Tempol, abolished the effect of maternal diabetes or high glucose on miR-322 and TRAF3 expression, respectively. A miRNA target prediction algorithm reveals 2 miR-322 binding sites the 3'-untranslated region (UTR) of TRAF3 mRNA. A RNA pull-down assay using biotin-labeled miR-322 revealed that miR-322 interacted with the 3'-UTR of TRAF3 mRNA at one specific binding site. The miR-322 mimic or TRAF3 knockdown blocked high glucose-increased TRAF3 protein expression and apoptosis, whereas the miR-322 inhibitor mimicked the effect of high glucose leading to TRAF3 up-regulation and apoptosis. This study demonstrates that both maternal diabetes and high glucose negatively regulate miR-322 through oxidative stress. miR-322 interacts with the 3'-UTR of TRAF3 and represses its translation. The miR-322-TRAF3 pathway is implicated in high glucose-induced caspase activation and apoptosis.
authors.affiliation: *Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang 110004, China, Department of Biochemistry and Molecular Biology and Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201 *Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang 110004, China, Department of Biochemistry and Molecular Biology and Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201.
authors.forename: Hui
authors.initials: H
authors.lastname: Gu
authors.affiliation: *Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang 110004, China, Department of Biochemistry and Molecular Biology and Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201.
authors.forename: Jingwen
authors.initials: J
authors.lastname: Yu
authors.affiliation: *Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang 110004, China, Department of Biochemistry and Molecular Biology and Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201.
authors.forename: Daoying
authors.initials: D
authors.lastname: Dong
authors.affiliation: *Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang 110004, China, Department of Biochemistry and Molecular Biology and Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201.
authors.forename: Qun
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: *Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang 110004, China, Department of Biochemistry and Molecular Biology and Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201.
authors.forename: Jian-Ying
authors.initials: JY
authors.lastname: Wang
authors.affiliation: *Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang 110004, China, Department of Biochemistry and Molecular Biology and Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201 *Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang 110004, China, Department of Biochemistry and Molecular Biology and Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201 pyang@fpi.umaryland.edu.
authors.forename: Peixin
authors.initials: P
authors.lastname: Yang
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001665:Binding Sites; D001786:Blood Glucose / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004789:Enzyme Activation; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D058953:Neural Stem Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D018384:Oxidative Stress; D011247:Pregnancy; D011254:Pregnancy in Diabetics; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D048008:TNF Receptor-Associated Factor 3 / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D020413:3' Untranslated Regions; D000975:Antioxidants; D001786:Blood Glucose; C582672:MIRN322 microRNA, mouse; D035683:MicroRNAs; D012333:RNA, Messenger; D048008:TNF Receptor-Associated Factor 3; C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; C505409:Casp3 protein, mouse; D053148:Caspase 3
keywords: TRAF3; apoptosis; high glucose; microRNA-322; neural stem cells; oxidative stress