Functional Effects of Endothelial Nitric Oxide Synthase Genetic Polymorphisms on Haemorheological Parameters in Healthy Human Individuals

The effect of endothelial Nitric Oxide Synthase G894T and T786C polymorphisms on Hypoxia-Inducible Factor-1 alpha expression in Sickle Cell Disease

Hypoxia-Inducible Factor-1α (HIF-1α) expression is upregulated in Sickle Cell Disease (SCD) and correlates with various laboratory markers of disease severity. Nitric Oxide plays a pivotal role in SCD pathophysiology and endothelial Nitric Oxide Synthase (NOS3) polymorphisms affect prognosis and laboratory parameters. This study questions the effect of NOS3 G894T and T786C polymorphisms on HIF-1α expression in SCD. We show that G894T polymorphism is a significant predictor of HIF-1α expression. Its effect is exerted independently of hemolysis/hemoglobin fragment concentrations, as shown in multiple regression analysis. Our results establish a novel modulator of HIF-1α expression on the mRNA level and indirectly support the role of nitric oxide in the pathophysiology of SCD.

Associations of the NOS3 rs1799983 polymorphism with circulating nitric oxide and lipid levels: a systematic review and meta-analysis

BACKGROUND

Circulating nitric oxide (NO) and lipid levels are closely associated with coronary artery disease (CAD). It is unclear whether the rs1799983 polymorphism in endothelial nitric oxide synthase (NOS3) gene is associated with plasma levels of NO and lipids. This systematic review and meta-analysis (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) aimed to clarify the relationships between the rs1799983 polymorphism and plasma levels of NO and lipids.

METHODS

Sixteen studies (2702 subjects) and 59 studies (14 148 subjects) were identified for the association analyses for NO and lipids, respectively. Mean difference (MD) and 95% CI were used to estimate the effects of the rs1799983 polymorphism on plasma NO and lipid levels. The primary outcome variable was NO, and the secondary outcomes included triglycerides, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C).

RESULTS

Carriers of the T allele had lower levels of NO (MD -0.27 μmol/L, 95% CI -0.42 to -0.12 μmol/L, p<0.001) and HDL-C (MD -0.07 mmol/L, 95% CI -0.14 to -0.00 mmol/L, p=0.04), and higher levels of TC (MD 0.13 mmol/L, 95% CI 0.06 to 0.20 mmol/L, p<0.001) and LDL-C (MD 0.14 mmol/L, 95% CI 0.05 to 0.22 mmol/L, p=0.002) than the non-carriers. Triglyceride levels were comparable between the genotypes.

CONCLUSION

The association between the NOS3 rs1799983 polymorphism and CAD may be partly mediated by abnormal NO and lipid levels caused by the T allele.