Association Study Of Coronary Atherosclerotic Disease And Polymorphisms In TNFSF4 And TNFRSF4 Gene In A Chinese Han Population

[Background]Recent research has demonstrated that inflammation plays a key role in coronary heart disease (CHD). In the pathogenesis of inflammation, various kinds of cells participate in this process, activated T cells are considered to be the most important one. Activated T cells are implicated in important cellular and molecular events in atherogenesis, which can produce pro-inflammatory cytokines and chemokines to promote local inflammation. Activation of T cells needs double signal pathways, MHC-antigenic peptide and B7-CD28, in addition, secondary signaling pathways are also essential, TNF superfamily members and TNF receptors superfamily members can form these pathways, for example, CD40/CD40L, OX40/OX40L, 4-1BB/4-1BBL, CD70/CD27 and TL1A/DR3. OX40/OX40L, as an important pathway, plays an important role in the process of coronary atherosclerotic disease (CAD). Through lots of research, we found that TNFSF4 gene, which encodes OX40L and TNFRSF4 gene, which encodes OX40 can play roles in the pathogenesis of CAD acting as important susceptibility genes. Meanwhile, some single nucleotide polymorphisms(SNPs) in TNFSF4 gene and TNFRSF4 gene were associated with myocardial infarction and coronary atherosclerotic disease in some populations. So far, the association studies between human TNFSF4 gene and TNFRSF4 gene in a Chinese Han population and CAD have not been reported. So the purpose of this study is to investigate whether SNPs in human TNFSF4 gene and TNFRSF4 gene in a Chinese Han population are associated with CAD by conducting case-control study. [Objective]Using case-control study to determine the association between SNPs in TNFSF4 and TNFRSF4 genes and CAD in a Chinese Han population, five SNPs in TNFSF4 gene including:rs1234314, rs45454293 in promotor region, two tag SNP rs3850641, rs1234313 in intron 1 region, one tag SNP rs3861950 in intron2 region and one tag SNP of intron5 (rs2298212), proxy of a functional variant in TNFRSF4 gene were selected for genotyping.[Methods]1. Blood samples from CAD patients and healthy controls in a Chinese Han population were collected and DNA was extracted from the white blood cells in peripheral blood.2. Genotyping:all SNPs in TNFSF4 gene were genotyped using PCR-RFLP methods in 547 CAD patients and 601 healthy controls and TNFRSF4 gene in 536 CAD patients and 544 healthy controls.3. Hardy-Weinberg equilibrium (HWE) were evaluated using chi-square test and make sure all the SNPs were at Hardy-Weinberg equilibrium in both CAD patient and healthy control groups.4. Compare the distribution difference of genotypic and allelic frequencies of every SNP in the two groups using chi-square test to determine whether the SNP was associated with CAD.5. Case-only study was conducted to determine the effect of TNFSF4 and TNFRSF4 gene variations on disease severity. All the patients were divided into three subgroups according to the numbers of coronary artery involved. The distribution of genotypic and allelic frequencies of all SNPs between subgroups were compared.6. Power calculation. PGA was used to calculated the statistic power of sample size to exclude the typeâ…¡error. [Results]1. The SNPs of rs1234314, rs45454293, rs3850641, rs1234313, rs3861950 in TNFSF4 gene were genetically polymorphic in a Chinese Han population and were in agreement to Hardy-Weinberg equilibrium in both groups. Neither genotypic nor allelic distribution was statistically different between CAD patients and healthy controls(all P>0.05). Substratification analysis of coronary artery involved vessels was performed, no significant difference was found between affected vessels in genotypic and allelic distribution(all P>0.05).2. The SNP of rs2298212 in TNFRSF4 gene was genetically polymorphic in a Chinese Han population and was in Hardy-Weinberg equilibrium in both groups. Neither genotypic nor allelic distribution was statistically different between CAD patients and healthy controls (all P>0.05). Substratification analysis of coronary artery involved vessels was performed, significant difference was found between single-vessel and triple-vessel in genotypic and allelic distribution (P<0.05).3. Power for genetic association analysis. Laying test criterion a is 0.05, supposing rare allelic frequency is 0.17, OR is 1.4, LD coefficient is 1.0, statistics efficiency of forthcoming samples has exceeded 80%.[Conclusions]1. None of SNPs rs1234314, rs45454293, rs3850641, rs1234313, rs3861950 in TNFSF4 gene was associated with CAD in a Chinese Han population.2. SNP rs2298212 in TNFRSF4 gene was not associated with CAD in a Chinese Han population. But this SNP is associated with the disease severity, which showed that TNFRSF4 gene may be involved in the development of the disease.