Intron 4 VNTR polymorphism of eNOS gene is protective for cardiac syndrome X.
ABSTRACT Microvascular abnormalities caused by endothelial dysfunction seem to be responsible for the myocardial ischemia in patients with cardiac syndrome X (CSX). Nitric oxide is a key mediator of endothelial function and is synthesized by endothelial nitric oxide synthase (eNOS). We investigated if the 3 potential polymorphisms of the eNOS gene (VNTR in intron 4, T786C polymorphism in the promoter region, and G894T polymorphism in exon 7) are independent risk factors for CSX. Sixty-nine patients with CSX and 73 healthy controls were studied. Genotypes were determined through polymerase chain reaction with or without restriction endonuclease digestions. Genotype distribution was significantly different between patients with CSX and controls for intron 4aa (allele for 4 repeats of 27 bp), intron 4aa genotype frequency being 3.2% and 6.8%, respectively. The presence of intron 4a is 3.2 (odds ratio) times protective (95% confidence interval, 1.5-6.8) for the risk of CSX disease. The protective effect of intron 4a polymorphism also holds after adjustment for age and sex and when the study group is limited to those without hypertension and hyperlipidemia. No significant difference was observed in genotype distribution of G894T and T786C polymorphism between patients with CSX and controls. In conclusion, intron 4aa genotype of eNOS gene is protective for CSX. No association was found between promoter and exon 7 polymorphisms of eNOS gene and CSX.
Article: Nitric oxide metabolism controlled by formaldehyde dehydrogenase (fdh, homolog of mammalian GSNOR) plays a crucial role in visual pattern memory in Drosophila.[show abstract] [hide abstract]
ABSTRACT: Nitric oxide (NO) plays an important role in learning and memory which is essential for animals to adapt to the external environment. However, little is known about the role of NO metabolism in this process. S-nitrosoglutathione reductase (GSNOR) is a key protein in the control of NO metabolism and protein S-nitrosation. To study the relationship between NO metabolism and learning and memory, the expression of gene fdh which is homolog to mammalian GSNOR was modulated by the Gal4/UAS system in Drosophila. The over-expression of the fdh in the central nervous system significantly increased GSNOR activity and induced visual pattern memory defects of Drosophila. The role of fdh in learning and memory was independent of development and was neuron-specific: over-expression of the fdh in the fan-shaped body induced memory defect, while over-expression in the mushroom body did not. The visual pattern memory defect could be rescued by co-expression with exogenous cGMP-dependent protein kinase (PKG). Moreover, fdh over-expression resulted in denitrosation of multiple proteins functionally enriched in vesicle-mediated transport, which is important for learning and memory. These results showed that regulation of NO metabolism plays an important role in learning and memory, and the mechanism may involve both NO-cGMP-PKG signaling pathway and S-nitrosation modification.Nitric Oxide 10/2010; 24(1):17-24. · 3.55 Impact Factor