title: MicroRNA-19b promotes macrophage cholesterol accumulation and aortic atherosclerosis by targeting ATP-binding cassette transporter A1.
abstract: BACKGROUND
  Macrophage accumulation of cholesterol leads to foam cell formation which is a major pathological event of atherosclerosis. Recent studies have shown that microRNA (miR)-19b might play an important role in cholesterol metabolism and atherosclerotic diseases. Here, we have identified miR-19b binding to the 3'UTR of ATP-binding cassette transporter A1 (ABCA1) transporters, and further determined the potential roles of this novel interaction in atherogenesis.
  
  
  OBJECTIVE
  To investigate the molecular mechanisms involved in a miR-19b promotion of macrophage cholesterol accumulation and the development of aortic atherosclerosis.
  
  
  RESULTS
  We performed bioinformatics analysis using online websites, and found that miR-19b was highly conserved during evolution and directly bound to ABCA1 mRNA with very low binding free energy. Luciferase reporter assay confirmed that miR-19b bound to 3110-3116 sites within ABCA1 3'UTR. MiR-19b directly regulated the expression levels of endogenous ABCA1 in foam cells derived from human THP-1 macrophages and mouse peritoneal macrophages (MPMs) as determined by qRT-PCR and western blot. Cholesterol transport assays revealed that miR-19b dramatically suppressed apolipoprotein AI-mediated ABCA1-dependent cholesterol efflux, resulting in the increased levels of total cholesterol (TC), free cholesterol (FC) and cholesterol ester (CE) as revealed by HPLC. The excretion of (3)H-cholesterol originating from cholesterol-laden MPMs into feces was decreased in mice overexpressing miR-19b. Finally, we evaluated the proatherosclerotic role of miR-19b in apolipoprotein E deficient (apoE(-/-)) mice. Treatment with miR-19b precursor reduced plasma high-density lipoprotein (HDL) levels, but increased plasma low-density lipoprotein (LDL) levels. Consistently, miR-19b precursor treatment increased aortic plaque size and lipid content, but reduced collagen content and ABCA1 expression. In contrast, treatment with the inhibitory miR-19b antisense oligonucleotides (ASO) prevented or reversed these effects.
  
  
  CONCLUSIONS
  MiR-19b promotes macrophage cholesterol accumulation, foam cell formation and aortic atherosclerotic development by targeting ABCA1.
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China; Laboratory of Clinical Anatomy, University of South China, Hengyang 421001, China.
authors.forename: Yun-Cheng
authors.initials: YC
authors.lastname: Lv
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China.
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Tang
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Peng
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China.
authors.forename: Guo-Jun
authors.initials: GJ
authors.lastname: Zhao
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China; Clinical Medical Research Institute of the First Affiliated Hospital, University of South China, Hengyang 421001, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yao
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China.
authors.forename: Xin-Ping
authors.initials: XP
authors.lastname: Ouyang
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China.
authors.forename: Ping-Ping
authors.initials: PP
authors.lastname: He
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China; Laboratory of Clinical Anatomy, University of South China, Hengyang 421001, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xie
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China.
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: Tan
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Deng-Pei
authors.initials: DP
authors.lastname: Tang
authors.affiliation: Department of Physiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Francisco S
authors.initials: FS
authors.lastname: Cayabyab
authors.affiliation: Department of Biochemistry and Molecular Biology, The Libin Cardiovascular Institute of Alberta, The University of Calgary, Health Sciences Center, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada.
authors.forename: Xi-Long
authors.initials: XL
authors.lastname: Zheng
authors.affiliation: Department of Pediatrics and Group on the Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta T6G 2S2, Canada.
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Zhang
authors.affiliation: Department of Cardiovascular Medicine, Second Affiliated Hospital of University of South China, Hengyang 421001, Hunan, China. Electronic address: tianguopingnhfe@163.com.
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Tian
authors.affiliation: Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang 421001, Hunan, China. Electronic address: tangchaoke@qq.com.
authors.forename: Chao-Ke
authors.initials: CK
authors.lastname: Tang
mesh_terms: D064286:ATP Binding Cassette Transporter 1 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000502:physiology; D000818:Animals; D001018:Aortic Diseases / Q000209:etiology* / Q000235:genetics / Q000378:metabolism; D016632:Apolipoprotein A-I / Q000378:metabolism; D001057:Apolipoproteins E / Q000172:deficiency; D050197:Atherosclerosis / Q000209:etiology* / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002460:Cell Line; D002784:Cholesterol / Q000378:metabolism*; D002788:Cholesterol Esters / Q000378:metabolism; D003094:Collagen / Q000032:analysis; D005487:Foam Cells / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D035683:MicroRNAs / Q000502:physiology*; D008969:Molecular Sequence Data; D058226:Plaque, Atherosclerotic / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid
chemical_list: D064286:ATP Binding Cassette Transporter 1; D016632:Apolipoprotein A-I; D001057:Apolipoproteins E; D002784:Cholesterol; D002788:Cholesterol Esters; D003094:Collagen; D035683:MicroRNAs; D012333:RNA, Messenger; C577836:ABCA1 protein, human; C577833:Abca1 protein, mouse; C549214:MIRN19A microRNA, human; C561642:MIRN19 microRNA, mouse
keywords: ABCA1; Atherosclerosis; Cholesterol accumulation; Macrophage; miR-19b