title: Microsatellite polymorphism in the heme oxygenase-1 gene promoter and the risk of atrial fibrillation in Taiwanese.
abstract: BACKGROUND
  Atrial fibrillation (AF) is associated with increased oxidative stress. Emerging evidence suggests that heme oxygenase-1 (HO-1) is a potent antioxidant system against various oxidative stress-related diseases. The human HO-1 promoter has a GT-repeat length polymorphism that can determine the level of gene transcription.
  
  
  OBJECTIVE
  The aim of this study is to assess the role of the GT-repeat polymorphism in the promoter region of the HO-1 gene in Chinese-Taiwanese patients with AF.
  
  
  RESULTS
  This study enrolled 200 AF patients and 240 controls, comparable for age and gender. In each subject, the length of GT-repeat polymorphism in the HO-1 promoter region was examined by polymerase chain reactions. The frequencies of long GT-repeat alleles (≧32) were significantly higher in AF patients than in controls. Multivariate analysis showed that the presence of long allele was significantly and independently associated with AF (odds ratio: 1.91, 95% CI 1.07-3.72; P = 0.028). Right atrial tissues from patients with chronic AF were investigated with immunoconfocal microscopy. Patients homozygous for shorter GT-repeat alleles exhibited greater HO-1 expression in their atria than those homozygous for longer alleles, which was reflected by less oxidative stress, myofibril degradation, and fibrosis in the atria of patients with shorter GT-repeat. In vitro, transient transfection assay in HL-1 atrial myocytes showed that the responsiveness of HO-1 transcriptional activity to tachypacing was inversely correlated with the length of the GT-repeats.
  
  
  CONCLUSIONS
  Our results suggest that the HO-1 microsatellite polymorphism may contribute to the genetic background of AF in Chinese-Taiwanese patients.
authors.affiliation: Cardiovascular Division, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Tao-Yuan, Taiwan.
authors.forename: Lung-An
authors.initials: LA
authors.lastname: Hsu
authors.affiliation: Cardiovascular Division, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Tao-Yuan, Taiwan.
authors.forename: Yung-Hsin
authors.initials: YH
authors.lastname: Yeh
authors.affiliation: Cardiovascular Division, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Tao-Yuan, Taiwan.
authors.forename: Chi-Tai
authors.initials: CT
authors.lastname: Kuo
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Taipei Veterans General Hospital, National Yang-Ming University College of Medicine, Taipei, Taiwan.
authors.forename: Ying-Hwa
authors.initials: YH
authors.lastname: Chen
authors.affiliation: Graduate Institute of Clinical Medical Sciences, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Gwo-Jyh
authors.initials: GJ
authors.lastname: Chang
authors.affiliation: Division of Cardiac Surgery, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Tao-Yuan, Taiwan.
authors.forename: Feng-Chun
authors.initials: FC
authors.lastname: Tsai
authors.affiliation: Cardiovascular Division, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Tao-Yuan, Taiwan.
authors.forename: Wei-Jan
authors.initials: WJ
authors.lastname: Chen
mesh_terms: D000368:Aged; D000483:Alleles; D044466:Asian People; D001281:Atrial Fibrillation / Q000208:ethnology / Q000235:genetics* / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D051547:Heme Oxygenase-1 / Q000235:genetics*; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D016017:Odds Ratio; D018384:Oxidative Stress; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D012306:Risk
chemical_list: D051547:Heme Oxygenase-1