The effect of single nucleotide polymorphism of -863C/A of TNF-α on binding activity of nuclear factor kappa B with DNA and the mechanism involved in sepsis

Objective To investigate the effect of -863C/A polymorphism of TNF-α gene on the NF-kappa B binding activity with DNA motif,and the regulation of TNF-α expression involved in the mechanism of sepsis.Methods Thirty patients with sepsis were divided into three groups according to the gene type of-863 C/C ,C/A,A/A.The blood sample was harvested and stimulated with LPS.The culture supernatant TNF-α production was measured by ELISA,and the activation of p65-p50 or p50-p50 in WBC nuclei was examined by EMSA.Results In vitro,the activation of NF-kappa B and expression of TNF-α in the whole blood stimulated with LPS were significantly lower at 1st and 2nd week after sepsis than at Oand 4th week of sepsis.The activation style of NF-kappa B in genotypes with -863A characterized with p50-p50 predominant and the level of p50-p50 in nuclei was higher than that of C/C genotype group.In contrast,the ratio of p65-p50 to p50-p50 was lower in C/A and A/A groups than in C/C group (0.4±0.2 vs 0.7 + 0.4).Meanwhile,the expression of TNF-α was decreased significantly along with the lower activation of p65-p50 dimer.Conclusion The data indicated that different genotypes of 863C/A polymorphism on TNF-α gene could regulate NF-kappa B p65-p50 and p50-p50 activation and the binding with DNA motif and the expression of downstream gene including TNF-α. Key words: Sepsis; Tumor necrosis factor alpha; Nuclear factor kappa B; Endotoxin; Single nucleotide polymorphism