title: Two functional polymorphisms of ROCK2 enhance arterial stiffening through inhibiting its activity and expression.
abstract: Derangement of Rho-associated kinases (ROCKs) has been related to coronary artery disease and stroke. ROCK2, rather than ROCK1, plays a predominant role in vascular contractility. The present study aims to test (1) the associations between ROCK2 single nucleotide polymorphisms (SNPs) and arterial stiffness, and (2) the molecular mechanism accounting for their effects. Stiffness parameters including beta (β), elasticity modulus (Ep) and pulse wave velocity (PWV) were obtained by carotid ultrasonography. Seven tagging SNPs of ROCK2 were initially genotyped in 856 subjects and significant SNPs were replicated in another group of 527 subjects. Two SNPs in complete linkage disequilibrium were found to be significantly associated with arterial stiffness. The major alleles of rs978906 (A allele) and rs9808232 (C allele) were associated with stiffer arteries. SNP rs978906 was predicted to influence microRNA(miR)-1183 binding to ROCK2, while rs9808232 causes amino acid substitution. To determine their functional impact, plasmid constructs carrying different alleles of the significant SNPs were created. Compared to rs978906G-allele constructs, cells transfected with rs978906A-allele constructs had higher baseline luciferase activities and were less responsive to miR-1183 changes. Oxidized-low density lipoprotein (Ox-LDL) suppressed miR-1183 levels and increased ROCK2 protein amounts. For rs9808232, cells transfected with C-allele constructs had significantly higher ROCK activities than those with A-allele constructs. Leukocyte ROCK activities were further measured in 52 healthy subjects. The average ROCK activity was highest in human subjects with CC genotype at rs9808232, followed by those with AC and lowest in AA. Taken together, the present study showed that two functional SNPs of ROCK2 increase susceptibility of arterial stiffness in the Chinese population. Non-synonymous SNP rs9808232 influences ROCK2 activity, while 3' UTR SNP rs978906 affects the ROCK2 protein synthesis by interfering miR-1183 binding.
authors.affiliation: Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yi-Chu
authors.initials: YC
authors.lastname: Liao
authors.affiliation: Division of Cardiology, Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan; Institute of Clinical Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Ping-Yen
authors.initials: PY
authors.lastname: Liu
authors.affiliation: Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Neurology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Hsiu-Fen
authors.initials: HF
authors.lastname: Lin
authors.affiliation: Department of Occupational Medicine, Kaohsiung Municipal Hsiaokang Hospital, Kaohsiung, Taiwan.
authors.forename: Wen-Yi
authors.initials: WY
authors.lastname: Lin
authors.affiliation: Section of Cardiology, Department of Medicine, University of Chicago, Chicago, USA.
authors.forename: James K
authors.initials: JK
authors.lastname: Liao
authors.affiliation: Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Genome Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: hjuo@kmu.edu.tw.
authors.forename: Suh-Hang H
authors.initials: SH
authors.lastname: Juo
mesh_terms: D001011:Aorta / Q000166:cytology; D001483:Base Sequence; D003710:Demography; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D008969:Molecular Sequence Data; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D015203:Reproducibility of Results; D059289:Vascular Stiffness / Q000235:genetics*; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics*
chemical_list: D035683:MicroRNAs; C515852:ROCK2 protein, human; D054460:rho-Associated Kinases
keywords: Arterial stiffness; Polymorphisms; ROCK2; microRNAs