title: NOS1 methylation and carotid artery intima-media thickness in children.
abstract: BACKGROUND
  Nitric oxide (NO) plays an important role in cardiovascular health by maintaining and regulating vascular tone and blood flow. Epigenetic regulation of NO synthase (NOS), the genes responsible for NO production, may affect cardiovascular disease, including the development of atherosclerosis in children.
  
  
  RESULTS
  We measured percentage DNA methylation using bisulfite conversion and pyrosequencing assays on DNA from buccal cells provided by 377 participants of the Children's Health Study on whom carotid artery intima-media thickness (CIMT) measurements were also collected. We examined a total of 16 CpG loci located within NOS1, NOS2A, NOS3, ARG1, and ARG2 genes responsible for NO production. CIMT was measured using high-resolution B-mode carotid ultrasound. The association between percentage DNA methylation in ARG and NOS genes with CIMT was evaluated using linear regression adjusted for sex, ethnicity, body mass index, age at CIMT, town of residence, and experimental plate for pyrosequencing reactions. Differences in the association by ethnicity and ancestral group were also evaluated. For a 1% increase in average DNA methylation of NOS1, CIMT increased by 1.2 μm (P=0.02). This association was greater in Hispanic children of Native American descent (β=2.3; P=0.004) than in non-Hispanic whites (β=0.3; P=0.71) or Hispanic whites (β=1.0; P=0.35).
  
  
  CONCLUSIONS
  DNA methylation of NOS1 has a plausible role in atherogenesis through regulation of NO production, although ancestry may alter the magnitude of this association.
authors.affiliation: Department of Preventive Medicine and Atherosclerosis Research Unit, University of Southern California, Los Angeles, CA.
authors.forename: Carrie V
authors.initials: CV
authors.lastname: Breton
authors.forename: Caron
authors.initials: C
authors.lastname: Park
authors.forename: Kim
authors.initials: K
authors.lastname: Siegmund
authors.forename: W James
authors.initials: WJ
authors.lastname: Gauderman
authors.forename: Lora
authors.initials: L
authors.lastname: Whitfield-Maxwell
authors.forename: Howard N
authors.initials: HN
authors.lastname: Hodis
authors.forename: Ed
authors.initials: E
authors.lastname: Avol
authors.forename: Frank D
authors.initials: FD
authors.lastname: Gilliland
mesh_terms: D000293:Adolescent; D050197:Atherosclerosis / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000201:enzymology* / Q000235:genetics*; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D059168:Carotid Intima-Media Thickness; D002648:Child; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I / Q000235:genetics* / Q000378:metabolism
chemical_list: D009569:Nitric Oxide; C496320:NOS1 protein, human; D052248:Nitric Oxide Synthase Type I
keywords: cardiovascular diseases; carotid artery intima-media thickness; epigenomics; nitric oxide synthase