title: Coronary-Heart-Disease-Associated Genetic Variant at the COL4A1/COL4A2 Locus Affects COL4A1/COL4A2 Expression, Vascular Cell Survival, Atherosclerotic Plaque Stability and Risk of Myocardial Infarction.
abstract: Genome-wide association studies have revealed an association between coronary heart disease (CHD) and genetic variation on chromosome 13q34, with the lead single nucleotide polymorphism rs4773144 residing in the COL4A2 gene in this genomic region. We investigated the functional effects of this genetic variant. Analyses of primary cultures of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) from different individuals showed a difference between rs4773144 genotypes in COL4A2 and COL4A1 expression levels, being lowest in the G/G genotype, intermediate in A/G and highest in A/A. Chromatin immunoprecipitation followed by allelic imbalance assays of primary cultures of SMCs and ECs that were of the A/G genotype revealed that the G allele had lower transcriptional activity than the A allele. Electrophoretic mobility shift assays and luciferase reporter gene assays showed that a short DNA sequence encompassing the rs4773144 site interacted with a nuclear protein, with lower efficiency for the G allele, and that the G allele sequence had lower activity in driving reporter gene expression. Analyses of cultured SMCs from different individuals demonstrated that cells of the G/G genotype had higher apoptosis rates. Immunohistochemical and histological examinations of ex vivo atherosclerotic coronary arteries from different individuals disclosed that atherosclerotic plaques with the G/G genotype had lower collagen IV abundance and thinner fibrous cap, a hallmark of unstable, rupture-prone plaques. A study of a cohort of patients with angiographically documented coronary artery disease showed that patients of the G/G genotype had higher rates of myocardial infarction, a phenotype often caused by plaque rupture. These results indicate that the CHD-related genetic variant at the COL4A2 locus affects COL4A2/COL4A1 expression, SMC survival, and atherosclerotic plaque stability, providing a mechanistic explanation for the association between the genetic variant and CHD risk.
authors.affiliation: Shantou University Medical College, Shantou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.
authors.forename: Fu Liang
authors.initials: FL
authors.lastname: Ng
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.|Royal Free Hospital, University College London, London, United Kingdom.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Chan
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.|First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Xiangyuan
authors.initials: X
authors.lastname: Pu
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.
authors.forename: Robin N
authors.identifier: 0000-0001-5240-7548
authors.initials: RN
authors.lastname: Poston
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.
authors.forename: Meixia
authors.initials: M
authors.lastname: Ren
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.
authors.forename: Weiwei
authors.initials: W
authors.lastname: An
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.
authors.forename: Ruoxin
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Shantou University Medical College, Shantou, China.
authors.forename: Jingchun
authors.identifier: 0000-0003-3769-0853
authors.initials: J
authors.lastname: Wu
authors.affiliation: First Affiliated Hospital of Shantou University Medical College, Shantou, China.
authors.forename: Shunying
authors.initials: S
authors.lastname: Yan
authors.affiliation: First Affiliated Hospital of Shantou University Medical College, Shantou, China.
authors.forename: Haiteng
authors.initials: H
authors.lastname: Situ
authors.affiliation: First Affiliated Hospital of Shantou University Medical College, Shantou, China.
authors.forename: Xinjie
authors.initials: X
authors.lastname: He
authors.affiliation: First Affiliated Hospital of Shantou University Medical College, Shantou, China.
authors.forename: Yequn
authors.initials: Y
authors.lastname: Chen
authors.affiliation: First Affiliated Hospital of Shantou University Medical College, Shantou, China.
authors.forename: Xuerui
authors.initials: X
authors.lastname: Tan
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.
authors.forename: Qingzhong
authors.initials: Q
authors.lastname: Xiao
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.
authors.forename: Arthur T
authors.initials: AT
authors.lastname: Tucker
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Caulfield
authors.affiliation: Shantou University Medical College, Shantou, China.|William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.|First Affiliated Hospital of Shantou University Medical College, Shantou, China.|Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.|NIHR Biomedical Research Centre in Cardiovascular Disease, Leicester, United Kingdom.
authors.forename: Shu
authors.initials: S
authors.lastname: Ye
mesh_terms: D000483:Alleles; D024141:Collagen Type IV / Q000235:genetics*; D003327:Coronary Disease / Q000235:genetics* / Q000473:pathology; D005260:Female; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism / Q000473:pathology; D009154:Mutation; D009203:Myocardial Infarction / Q000235:genetics* / Q000473:pathology; D058226:Plaque, Atherosclerotic / Q000235:genetics / Q000473:pathology; D020641:Polymorphism, Single Nucleotide
chemical_list: C502625:COL4A2 protein, human; D024141:Collagen Type IV