Polymorphism in the 5′-Flanking Region of Human Glutamate-Cysteine Ligase Modifier Subunit Gene Is Associated With Myocardial Infarction

Abstract

Background-Human glutamate-cysteine ligase (GCL) is a rate-limiting enzyme for the synthesis of glutathione that plays a crucial role in antioxidant defense mechanisms in most mammalian cells, including vascular cells. Oxidants transcriptionally upregulate GCL genes for glutathione synthesis, providing a protective mechanism against oxidative stress-induced cellular dysfunction. This study examined the hypothesis that variation in the GCL genes may be associated with coronary artery disease in which oxidative stress plays a pathogenetic role. Methods and Results-We searched for the common variants in the 5Ј-flanking region of the GCL modifier subunit (GCLM) gene in patients with myocardial infarction (MI). We found a polymorphism (Ϫ588C/T) in which the T allele showed lower promoter activity (40% to 50% of C allele) in response to oxidants in the luciferase reporter gene assay. Allele frequencies were determined by polymerase chain reaction-based analysis of restriction fragment length polymorphism in 429 patients with MI and 428 control subjects (as defined by angiography) in Kumamoto Prefecture, Japan. The frequency of the T polymorphism was significantly higher in the MI group than in the control group (CT and TT genotypes: 31.5% in MI group versus 19.2% in control group; PϽ0.001). In multiple logistic regression analysis, the T polymorphism was a risk factor for MI independent of traditional coronary artery disease risk factors (odds ratio, 1.98; 95% confidence interval, 1.38 to 2.83; PϽ0.001). Conclusions-These findings suggest that the Ϫ588T polymorphism of the GCLM gene may suppress GCLM gene induction in response to oxidants and that it is a genetic risk factor for MI.

Polymorphism in Glutamate-Cysteine Ligase Modifier Subunit Gene Is Associated With Impairment of Nitric Oxide–Mediated Coronary Vasomotor Function

“…1,5-7 However, we have previously shown that the Ϫ588T polymorphism suppresses the increase in GCLM gene expression in response to oxidative stress and that this polymorphism is associated with low plasma GSH concentration. 8 Therefore, the Ϫ588T polymorphism may weaken the intracellular production of GSH in response to oxidative stress, leading to an increase in the susceptibility to impairment of NO-mediated endothelial vasomotor function. In addition, endothelium-derived NO has various antiatherothrombogenetic properties.…”

“…Genotyping was performed by a polymerase chain reaction-based method of restriction fragment length polymorphism with forward (5Ј-CTCAAGGGCAAAGACTCA-3Ј) and reverse (5Ј-CCGCCTGGTGAGGTAGACAC-3Ј) primers, as described previously. 8 …”

“…Recently, we found polymorphism Ϫ588C/T in the 5Ј-flanking region of the GCLM gene. 8 The minor Ϫ588T allele of the polymorphism suppresses oxidant-induced upregulation of GCLM gene expression and is associated with lower plasma GSH levels, and this polymorphism is a genetic risk factor for myocardial infarction (MI). 8 However, mechanisms by which this polymorphism is linked to the genesis of MI remain undefined.…”

“…8 The minor Ϫ588T allele of the polymorphism suppresses oxidant-induced upregulation of GCLM gene expression and is associated with lower plasma GSH levels, and this polymorphism is a genetic risk factor for myocardial infarction (MI). 8 However, mechanisms by which this polymorphism is linked to the genesis of MI remain undefined. The present study thus examined whether this polymorphism may be implicated in coronary endothelial vasomotor dysfunction, which plays an important role in the pathogenesis of coronary artery disease.…”

Levels of 2-thiothiazolidine-4-carboxylic acid (TTCA) and effect modification of polymorphisms of glutathione-related genes in vulcanization workers in the southern Sweden rubber industries

“…The T allele has shown lower promoter activity compared to the C allele in vitro in human endothelial cells (Koide et al 2003). The 5'-flanking region of GCLM contains a polymorphism (-588C/T) in which the T allele has shown lower promoter activity compared to C allele when exposed to oxidants (Nakamura et al 2002). Nakamura et al (2002) also showed that the plasma GSH levels were significantly lower in CT and TT genotypes than in CC genotype.…”