Polymorphism eNOS Glu298Asp modulates the inflammatory response of human peripheral blood mononuclear cells

Abstract

Introduction: Nitric oxide is a gaseous radical produced by the nitric oxide endothelial synthase (eNOS) whose most studied physiological action is the vasodilation. However, it also acts in the defense of the organism through the formation of cytotoxic radicals, which can potentiate the inflammatory lesion of the cells. The Glu298Asp is a single nucleotide polymorphism (SNP) in the eNOS gene related to the risk of cardiovascular disease. Blacks present a higher prevalence of hypertension and cardiovascular mortality. Then, we aimed to evaluate the influence of Glu298Asp polymorphism on inflammatory response in vitro and gene expression in blacks.

Material and methods: Peripheral blood mononuclear cells (PBMC) from blacks with different Glu298Asp genotypes were treated with phytohemagglutinin (PHA), a mitogen and activator of T cells. Oxidative, inflammatory markers, and expression of inflammation genes were evaluated.

Results: The genotype frequencies were TT 6.7%; TG 29.3% and GG 64.0%. Activation of PBMCs with 125 μg of PHA modulated the expression of inflammatory genes and increased levels of inflammatory cytokines. The T allele showed increased susceptibility to inflammation (higher levels of interleukin 1, interleukin 6 and tumor necrosis factor alpha; p < 0.001). The G allele exhibited protection through higher levels of nitric oxide (p < 0.001) and fewer inflammatory cytokines.

Conclusion: Despite methodological limitations related to in vitro assays, the whole of results suggested that Glu298Asp modulates inflammatory genes, the T allele is more susceptible to inflammation and the G allele is protective.

Keywords: Afrodescendant; Inflammation; Negroid race; eNOS.