Mitsutoshi Oguri

Association of genetic variants with myocardial infarction in Japanese individuals with metabolic syndrome

OBJECTIVE The purpose of the present study was to identify genetic variants that confer susceptibility to myocardial infarction (MI) in individuals with metabolic syndrome (MetS). METHODS The study population comprised 1887 Japanese individuals with MetS, including 773 subjects with MI and 1114 controls. The genotypes for 136 polymorphisms of 97 candidate genes were determined. RESULTS An initial screen by the chi-square test revealed that seven polymorphisms were significantly (false discovery rate<0.05) associated with the prevalence of MI in individuals with MetS. Subsequent multivariable logistic regression analysis with adjustment for covariates revealed that the G-->A (Ser89Asn) polymorphism of UTS2 [odds ratio (OR), 1.90; 95% confidence interval (CI), 1.18-3.08], the 2445G-->A (Ala54Thr) polymorphism of FABP2 (OR, 1.72; 95% CI, 1.23-2.40), the -11377C-->G polymorphism of ADIPOQ (OR, 1.43; 95% CI, 1.15-1.79), the -231A-->G polymorphism of EDNRA (OR, 0.65; 95% CI, 0.48-0.89), and the -108/3G-->4G polymorphism of PDX1 (OR, 0.64; 95% CI, 0.48-0.87) were significantly (P<0.05) associated with MI. The variant alleles of UTS2, FABP2, and ADIPOQ were risk factors for MI, whereas the variant alleles of EDNRA and PDX1 were protective against this condition. A stepwise forward selection procedure demonstrated that UTS2, FABP2, ADIPOQ, EDNRA, and PDX1 genotypes were significant (P<0.05) and independent determinants of MI. CONCLUSIONS Determination of genotypes for these polymorphisms of UTS2, FABP2, ADIPOQ, EDNRA, and PDX1 may prove informative for assessment of the genetic risk for MI in Japanese individuals with MetS.

Association of a polymorphism of BTN2A1 with myocardial infarction in East Asian populations

OBJECTIVE We have performed a genome-wide association study (GWAS) to identify genetic variants that confer susceptibility to myocardial infarction (MI) in Japanese and Korean populations. METHODS A total of 17,447 Japanese or Korean individuals from four independent subject panels was examined. Japanese subject panels A, B, and C comprised 134 individuals with MI and 137 controls, 1431 individuals with MI and 3161 controls, and 643 individuals with MI and 1347 controls, respectively, whereas the Korean population comprised 1880 individuals with MI and 8714 controls. A GWAS for MI was performed in Japanese subject panel A with the use of the Affymetrix GeneChip Human Mapping 500K Array Set. RESULTS Seventy single nucleotide polymorphisms (SNPs) significantly (P<1.0×10(-7)) associated with MI by the GWAS were examined further in Japanese subject panel B, revealing two SNPs (rs6929846 of BTN2A1, rs2569512 of ILF3) to be significantly (P<0.0007) associated with MI. The rs6929846 SNP of BTN2A1, but not rs2569512 of ILF3, was also significantly associated with MI in Japanese subject panel C. However, the association of neither rs6929846 nor rs2569512 with MI was replicated in the Korean population. CONCLUSION BTN2A1 may be a susceptibility gene for MI in Japanese individuals.

Association of Genetic Variants with Chronic Kidney Disease in Japanese Individuals

BACKGROUND AND OBJECTIVES Although genetic linkage analyses and association studies have implicated several loci and candidate genes in predisposition to chronic kidney disease (CKD), the genes that underlie genetic susceptibility to this condition have remained uncharacterized. The purpose of the present study was to identify genetic variants that confer susceptibility to CKD in Japanese individuals. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The study population comprised 5217 Japanese individuals (2955 men, 2262 women), including 778 subjects (480 men, 298 women) with CKD [estimated GFR (eGFR), <50 ml min(-1) 1.73 m(-2)] and 4439 controls (2475 men, 1964 women; eGFR, > or =60 ml min(-1) 1.73 m(-2)). The genotypes for 40 polymorphisms of 32 candidate genes were determined. RESULTS The chi-square test and multivariable logistic regression analysis with adjustment for covariates revealed that the -219G-->T polymorphism of APOE, the -519A-->G of MMP1, the -866G-->A of UCP2, the -1607/1G-->2G of MMP1, the A-->G (Lys45Glu) of MMP3, the G-->A (Ala163Thr) of AGTR1, the G-->A (Gly670Arg) of PECAM1, and the -55C-->T of UCP3 were significantly (false discovery rate <0.05) associated with CKD. Comparison of allele frequencies of these polymorphisms by the chi-square test between subgroups of CKD and control subjects individually matched for covariates revealed that the -519A-->G of MMP1 and the -866G-->A of UCP2 were significantly (P < 0.05) associated with CKD. CONCLUSIONS MMP1 and UCP2 may be susceptibility loci for CKD in Japanese individuals. Determination of genotypes for these polymorphisms may prove informative for prediction of genetic risk for CKD.

Identification of hypo- and hypermethylated genes related to atherosclerosis by a genome-wide analysis of DNA methylation

Epigenetic modification, particularly changes in DNA methylation at gene promoters, is implicated in the pathogenesis of atherosclerosis. However, the analysis of DNA methylation in atherosclerosis has been limited to a few selected candidate genes. In this study, we therefore performed a genome-wide analysis of DNA methylation in the atherosclerotic human aorta. A total of 48 post-mortem human aortic intima specimens were examined. To avoid the effects of interindividual variation, we performed intraindividual paired comparisons between atheromatous plaque lesions and corresponding plaque-free tissue for 24 subjects. Bisulfite-modified genomic DNA was analyzed for DNA methylation with a specific microarray (Illumina HumanMethylation450 BeadChip). We compensated for multiple comparisons by applying Bonferronis correction for statistical significance of association. DNA methylation was significantly (P<1.03x10⁻⁷) reduced at 15 CpG sites in 14 genes and increased at 30 CpG sites in 22 genes in atheromatous plaque compared with plaque-free intima. Three of the hypomethylated genes [Drosophila headcase (HECA), early B-cell factor 1 (EBF1) and nucleotide-binding oligomerization domain containing 2 (NOD2)] and three of the hypermethylated genes [human mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4), zinc finger E-box binding homeobox 1 (ZEB1) and FYN] were previously been implicated in atherosclerosis. The overexpression of HECA, EBF1 or NOD2 or the suppression of MAP4K4, ZEB1 or FYN expression in cultured HEK293 cells resulted in significant (P<4.80x10⁻⁷) changes in the expression of atherosclerosis-related genes, as determined with an expression microarray (Illumina HumanHT-12 v4 Expression BeadChip). Our findings suggested that HECA, EBF1 and NOD2 were significantly hypomethylated, whereas MAP4K4, ZEB1 and FYN were hypermethylated, in atheromatous plaque lesions compared with plaque-free intima. Epigenetic mechanisms may thus contribute to the pathogenesis of atherosclerosis.

Association of six genetic variants with myocardial infarction

Although various genes that confer susceptibility to myocardial infarction (MI) have been identified for Caucasian populations in genome-wide association studies (GWAS), genetic variants related to this condition in Japanese individuals have not been identified definitively. The aim of the present study was to examine an association of MI in Japanese individuals with 29 polymorphisms identified as susceptibility loci for MI or coronary artery disease in Caucasian populations by meta-analyses of GWAS. The study subjects comprised 1,824 subjects with MI and 2,329 controls. Genotypes of the polymorphisms were determined by Luminex bead-based multiplex assay. To compensate for multiple comparisons, we adopted the criterion of a false discovery rate (FDR) of <0.05 for statistical significance for association. Comparisons of allele frequencies by the χ(2) test revealed that rs9369640 of the phosphatase and actin regulator 1 gene (PHACTR1, FDR=0.0007), rs4977574 of the CDKN2B antisense RNA 1 gene (CDKN2B-AS1, FDR=0.0038), rs264 of the lipoprotein lipase gene (LPL, FDR=0.0061), rs599839 of the proline/serine-rich coiled-coil 1 gene (PSRC1, FDR=0.0118), rs9319428 of the fms-related tyrosine kinase 1 gene (FLT1, FDR=0.0118) and rs12413409 of the cyclin and CBS domain divalent metal cation transport mediator 2 gene (CNNM2, FDR=0.0300) were significantly associated with MI. Multivariate logistic regression analysis with adjustment for covariates revealed that rs9369640 (P=0.0005; odds ratio, 0.89), rs4977574 (P=0.0001; odds ratio, 1.50), rs264 (P=0.0405; odds ratio, 0.85), rs599839 (P=0.0003; odds ratio, 0.68), rs9319428 (P=0.0155; odds ratio, 1.20) and rs12413409 (P=0.0076; odds ratio, 0.66) were significantly (P<0.05) associated with MI. PHACTR1, CDKN2B-AS1, LPL, PSRC1, FLT1 and CNNM2 may thus be susceptibility loci for MI in Japanese individuals.

Impact of matrix metalloproteinase-2 levels on long-term outcome following pharmacological or electrical cardioversion in patients with atrial fibrillation

AIMS The aim of this study was to evaluate the role of matrix metalloproteinases (MMPs) for the prediction of long-term maintenance of sinus rhythm (SR) after cardioversion in atrial fibrillation (AF). METHODS AND RESULTS The study comprised 102 patients with AF. Pharmacological cardioversion was attempted for a 4-week period with anti-arrhythmic drugs in all patients. Those who failed medication underwent electrical cardioversion. Blood samples for biomarkers and echocardiographic data were obtained at baseline. Thirty-four patients (33.3%) converted to SR by pharmacological (n = 22) and electrical (n = 12) cardioversion and maintained it (SR group). The remaining 68 patients were refractory to the AF (RAF) group including recurrence (n = 22) and unsuccessful treatment (n = 46) after electrical/pharmacological cardioversion. Refractory AF was significantly associated with the duration of AF, hypertension, left atrial diameter, brain natriuretic peptide, MMP-2, and tissue inhibitor of MMP-2. For both multivariable logistic regression analysis and stepwise forward selection procedure, the duration of AF >5 months [odds ratio (OR) 15.32] and MMP-2 >767.0 ng/mL (OR 4.84) were significantly associated with RAF. CONCLUSION Our study suggests that elevated MMP-2 and longer AF duration increased the risk for difficulty in restoring SR in AF patients. Stratification of subjects according to the MMP-2 level may therefore be important for the effective management of AF.

Diagnostic accuracy of cardiac markers for myocardial damage after radiofrequency catheter ablation

AimsThis study compares serum markers of myocardial damage incurred during radiofrequency catheter ablation (RFCA).Methods and resultsBlood was sampled from 34 patients with atrial flutter (n = 16), atrioventricular nodal reentrant tachycardia (AVNRT; n = 13), and Wolff–Parkinson–White syndrome (WPW; n = 5) to measure creatine kinase MB subfraction (CK-MB), human heart-type fatty acid protein (h-FABP), and cardiac troponin T (cTnT) values at baseline and after RFCA. The controls comprised 12 patients without significant elevation of all myocardial markers during electrophysiological study (EPS) without RFCA. h-FABP values did not elevate significantly, whereas CK-MB and cTnT demonstrated significant change after RFCA (P < 0.001). Neither peak h-FABP nor CK-MB correlated with following RFCA parameters: delivery duration, number of RFCA discharges, and cumulative RFCA energy. In contrast, correlations were significant between mean peak values of cTnT and these RFCA parameters (all P < 0.05). The sensitivity (71.6%) and specificity (35.6%) of h-FABP were inferior to those of cTnT (93.3% and 89.8%, respectively).Conclusionh-FABP is an insensitive and less specific marker of myocardial damage in RFCA much along the lines of CK-MB and when compared with the proven accuracy of cTnT.

Genetic risk for myocardial infarction determined by polymorphisms of candidate genes in a Japanese population

Background: Although several environmental factors influence the development of myocardial infarction (MI), genetic factors have been shown to contribute to individual susceptibility to this condition. Objective: To identify gene polymorphisms that confer susceptibility to MI in order to allow assessment of genetic risk for this condition. Methods: 3433 unrelated Japanese people (1931 men, 1502 women) were entered into the study. These comprised 1328 subjects with MI (1036 men, 292 women) and 2105 controls (895 men, 1210 women). The genotypes for 40 polymorphisms of 31 candidate genes were determined with a method that combines PCR and sequence-specific oligonucleotide probes with suspension array technology. Results: The χ2 test revealed that six polymorphisms were significantly (false discovery rate <0.05) related to the prevalence of MI. Further examination by multivariable logistic regression analysis with adjustment for age, sex, body mass index and the prevalence of hypertension, diabetes mellitus and hypercholesterolaemia, in addition to a stepwise forward selection procedure found that the A→C (Gln1334His) polymorphism (rs3742207) of the collagen type IV alpha-1 gene (COL4A1) and the A→G polymorphism (rs4804611) of the zinc finger protein 627 gene (ZNF627) were significantly (p<0.05) associated with the prevalence of MI. The variant C allele of COL4A1 was protective against MI, whereas the variant G allele of ZNF627 represented a risk factor for this condition. Conclusions: Determination of genotypes for COL4A1 and ZNF627 may prove informative for assessment of the genetic risk for MI.

Oxido-reductive regulation of vascular remodeling by receptor tyrosine kinase ROS1

Angioplasty and stenting is the primary treatment for flow-limiting atherosclerosis; however, this strategy is limited by pathological vascular remodeling. Using a systems approach, we identified a role for the network hub gene glutathione peroxidase-1 (GPX1) in pathological remodeling following human blood vessel stenting. Constitutive deletion of Gpx1 in atherosclerotic mice recapitulated this phenotype of increased vascular smooth muscle cell (VSMC) proliferation and plaque formation. In an independent patient cohort, gene variant pair analysis identified an interaction of GPX1 with the orphan protooncogene receptor tyrosine kinase ROS1. A meta-analysis of the only genome-wide association studies of human neointima-induced in-stent stenosis confirmed the association of the ROS1 variant with pathological remodeling. Decreased GPX1 expression in atherosclerotic mice led to reductive stress via a time-dependent increase in glutathione, corresponding to phosphorylation of the ROS1 kinase activation site Y2274. Loss of GPX1 function was associated with both oxidative and reductive stress, the latter driving ROS1 activity via s-glutathiolation of critical residues of the ROS1 tyrosine phosphatase SHP-2. ROS1 inhibition with crizotinib and deglutathiolation of SHP-2 abolished GPX1-mediated increases in VSMC proliferation while leaving endothelialization intact. Our results indicate that GPX1-dependent alterations in oxido-reductive stress promote ROS1 activation and mediate vascular remodeling.

Association of genetic variants with hypertension in a longitudinal population-based genetic epidemiological study

We previously identified 9 genes and chromosomal region 3q28 as susceptibility loci for Japanese patients with myocardial infarction, ischemic stroke, or chronic kidney disease by genome-wide or candidate gene association studies. In the present study, we investigated the possible association of 13 single nucleotide polymorphisms (SNPs) at these 10 loci with the prevalence of hypertension or their association with blood pressure (BP) in community-dwelling individuals in Japan. The study subjects comprised 6,027 individuals (2,250 subjects with essential hypertension, 3,777 controls) who were recruited into the Inabe Health and Longevity Study, a longitudinal genetic epidemiological study on atherosclerotic, cardiovascular and metabolic diseases. The subjects were recruited from individuals who visited the Health Care Center of Inabe General Hospital for an annual health checkup, and they are followed up each year (mean follow-up period, 5 years). Longitudinal analysis with a generalized estimating equation and with adjustment for age, gender, body mass index and smoking status revealed that rs2116519 of family with sequence similarity 78, member B (FAM78B; P=0.0266), rs6929846 of butyrophilin, subfamily 2, member A1 (BTN2A1; P= 0.0013), rs146021107 of pancreatic and duodenal homeobox 1 (PDX1; P=0.0031) and rs1671021 of lethal giant larvae homolog 2 (Drosophila) (LLGL2; P=0.0372) were significantly (P<0.05) associated with the prevalence of hypertension. Longitudinal analysis with a generalized linear mixed-effect model and with adjustment for age, gender, body mass index and smoking status among individuals not taking anti-hypertensive medication revealed that rs6929846 of BTN2A1 was significantly associated with systolic (P=0.0017), diastolic (P=0.0008) and mean (P=0.0005) BP, and that rs2116519 of FAM78B, rs146021107 of PDX1 and rs1671021 of LLGL2 were significantly associated with diastolic (P=0.0495), systolic (P=0.0132), and both diastolic (P=0.0468) and mean (0.0471) BP, respectively. BTN2A1 may thus be a susceptibility gene for hypertension.