| Part1Association Study of Common Variants in PFN1 withEssential Hypertension in a Han Chinese PopulationBackground and Objectives Animal researches reported that the dysfunction of profilin1(PFN1)was involved in the physiological arterial stiffness and vascular remodeling linking to the aetiology of hypertension(HT).This study mainly aims at evaluating the association of PFN1 and essential hypertension(EH)in a Han Chinese population.Subjects and methods A case-control study was conducted in a rural population using the epidemiological cluster sampling approach in Yixing,Jiangsu province,China in 2009.A total of 4128 subjects were recruited at baseline including 2012hypertensive cases and 2116 normotensives.Ninety-four elderly subjects with normal blood pressure were enrolled to match the age of hypertension cases.Finally,a case-control study of hypertension was conducted,and 2116 with normal blood pressure at baseline were followed up to collect the incidence of hypertension.The single nucleotide polymorphisms(SNPs)were selected to cover PFN1 gene starting from the upstream 5kb to the downstream 2kb.ENO3 is located in a 4kb upstream region to PFN1 and thus the SNPs at ENO3 are also included in this study.According to linkage disequilibrium,the criteria of minor allele frequency(MAF)?0.05 and r~2?0.8 were used to select tagging single nucleotide polymorphisms(tagSNPs).Meanwhile,bioinformatics function prediction of selected SNPs was carried out.Finally,two tagSNPs rs238243 and rs2233656 at PFN1 and two tagSNPs rs238238 and rs238239at ENO3 were selected.Profilin1 in blood plasma was measured by Enzyme-linked immunosorbent assay.The differences between cases and controls were assessed with unpaired Student?s t-test(quantitative variables)and two-sided Chi-square(?2)test(qualitative variables).Among the control subjects,the genotype frequencies were tested with Fisher exact Chi-square(?2)test for Hardy-Weinberg equilibrium.Logistic and Cox regression were applied to evaluate the association of four tagSNPs of PFN1and ENO3 with EH.The haplotype was constructed using HAPSTAT 3.0 software to test the associations of statistical haplotypes with HT.General linear model(GLM)was applied to compare blood pressure levels between genotypes.Profilin1concentration with non-Gaussian distribution was expressed as median(interquartile range),and the differences of profilin1 between HT cases and controls as well as among genotypes were assessed with nonparametric tests.Results There was no significant association of the four SNPs with EH between HT cases and controls even after adjustment for gender,age,glucose,HDL-C,BMI,LDL-C,drinking,smoking,TC and TG(P>0.05).Haplotype analysis didn't identify any significant haplotype with HT.There were no statistical difference of systolic blood pressure and diastolic blood pressure among different genotypes in antihypertensive-treated group and untreated group.In follow-up population,there was no significant association of candidate SNPs with HT even after adjustment for covariates(all P>0.05).Of note,the plasma profilin1 level in HT cases was significantly higher than that in control subjects[96.93(11.91,242.46)vs.26.68(1.95,156.79)ng/ml,P=0.011].The profilin1 levels in controls significantly decreased with variation of rs238243 at PFN1(P=0.041),and the profilin1 levels in HT cases increased with variation of rs238238 at ENO3(P=0.004).Conclusions Our results suggest that HT cases displayed an elevated plasma profilin1.Variants of rs238243 and rs238238 might regulate profilin1 expression by epigenetic modification and indirectly affects the susceptible threshold of EH.Part2 Association Study of Gene Polymorphisms in TGF-?1 Signal Pathway with Essential Hypertension and StrokeBackground and ObjectivesAt present,hypertension has become a major public health problem in China.However,elevated blood pressure has been proved the primary and independent modifiable risk factor for stroke.Therefore,it is of great significance to study the pathogenesis of hypertension and cerebrovascular disease.Essential hypertension(EH)is the result of the interaction of genetic and environment factors.Vascular remodeling,as the main pathological basis of essential hypertension,has been led to the decrease of cerebral blood flow,the change of cerebral artery hemodynamics and the remodeling of cerebral artery,thus increasing the risk of stroke.Transforming growth factor beta 1 can regulate cell proliferation and differentiation,extracellular matrix deposition and vascular regeneration,which participate in vascular development and remodeling.The association of TGFB1 gene and TGFBR1 gene with essential hypertension in northern Chinese Han population,TGFBR2 gene and TGFBRAP1 gene with essential hypertension in southern Chinese Han population has been previously reported.The results suggest that the TGF-beta 1 signaling pathway is closely associated with hypertension/blood pressure susceptibility.In addition,there was a strong correlation between plasma profilin1 and TGF-?1 in hypertension cases and controls(r=0.8),but a week correlation in stroke cases(r=0.2).Here,a case-control study and follow-up study was conducted to evaluate the association of TGFB1 gene,TGFBR1 gene and TGFBR3 gene in TGF-beta 1 signaling pathway with essential hypertension in southern Chinese Han population,and to explore the relationship between TGFB1 gene,TGFBR1 gene,TGFBR2 gene,TGFBR3 gene and TGFBRAP1 gene and incident hypertension and stroke in southern Chinese Han population.Moreover,the effects of multiple gene-gene and gene-environment interactions on essential hypertension and stroke was also investigated.Subjects and methodsThe subjects recruited has been described in the first part.Excluding 94 matched elderly controls and 30 hypertension cases with history of stroke at baseline,4,098 subjects were further followed up for stroke incidence and 2,116 normotensives were prospectively followed up for hypertension incidence.According to linkage disequilibrium and functional site bioinformatics prediction analysis,thirty-seven tagging single nucleotide polymorphisms(tagSNPs)were selected.Multiple unconditional logistic regression analysis was applied to evaluate the genetic effects of screened SNPs and weighted genetic risk score on hypertension.Cox regression was applied to analyze the association of TGF-beta 1 pathway gene polymorphisms with incident hypertension and ischemic stroke in follow-up study.General linear model was applied to compare blood pressure levels and plasma TGF-?1 protein level among genotypes.Likelihood ratio test and MB-MDR were used to conduct gene-gene interaction.ResultsSingle locus analysis for the thirty-seven tagSNPs of TGF-beta pathway gene with HT showed that the variation of TGFBR3 rs12032588 was significantly associated with increased risk of hypertension in the general population,after adjustment for age,gender,TC,BMI,TG,LDL-C,GLU,HDL-C,smoking status,and drinking status,OR(95%CI)of additive model was 1.152(1.025-1.295),and P value was 0.018.Further stratification analysis found that in ?55 years groups,TGFBR1 rs6478974 and TGFBR1 rs10512263 were significantly associated with decreased risk of hypertension,the adjusted ORs(95% CIs)of the additive model were 0.890(0.796-0.995)and 0.865(0.762-0.981),and P value were 0.040 and 0.024.In<55 years groups,the variation of TGFBR1 rs10988705 was significantly associated with decreased risk of hypertension,the adjusted OR(95% CI)of the additive model was 0.697(0.500-0.971),and P value was 0.033.In males,the variations of TGFBR1 rs6478974,TGFBR3 rs1805110 and TGFBR3 rs12567680 were significantly associated with hypertension,the adjusted ORs(95% CIs)of the additive model were 0.856(0.741-0.989),0.859(0.745-0.990)and 0.847(0.738-0.973),and P value were 0.035,0.036 and 0.019;TGFBR3 rs284878 was significantly associated with increased risk of hypertension,the adjusted OR(95% CI)of the additive model was 1.201(1.013-1.423),and P value was 0.035.Multi-loci genetic risk score analysis indicated that compared with?P25(GRS?1.66),the risk of hypertension significantly elevated with the increase of GRS(Pt rend < 0.001).The adjusted ORs(95% CIs)of P50(1.67 ?GRS ?1.95),P75(1.96 ? GRS ?2.19)and P95(GRS ? 2.20)were 1.213(1.014-1.451),1.420(1.177-1.713)and 1.608(1.311-1.973).The follow-up study of hypertension showed that in<55 years groups,TGFB1 rs12980942 variation was significantly associated with increased incidence risk of hypertension,after adjustment for age,gender,diabetes,TC,TG,BMI,LDL-C,HDLC,smoking status,and drinking status,HR(95%CI)of additive model was 1.288(1.039-1.598),and P value was 0.021;TGFBR1 rs12346650 and TGFBR1 rs1888223 variation was significantly associated with decreased incidence risk of hypertension,the adjusted HRs(95% CIs)of the additive model were 0.717(0.533-0.965)and 0.745(0.600-0.926),and P value were 0.028 and 0.008;in addition,the incidence risk of hypertension in CT/TT carriers of TGFB1 rs8105161 was 1.477 times higher than that in carriers of CC genotype(P=0.034).In drinkers,TGFBR2 rs3773645 C>G variation was significantly associated with increased incidence risk of hypertension,the adjusted HR(95% CI)of the additive model was 1.340(1.058-1.698),and P value was 0.015;The incidence risk of hypertension in AG/GG carriers of TGFB1 rs13168506 was 1.494 times higher than that in carriers of AA genotype(P=0.026).In males,non-smokers and non-drinkers,TGFBR2 rs749794 G>A variation was negatively correlated with the incidence of hypertension,the adjusted HRs(95% CIs)of the additive model were 0.786(0.65-0.95),0.857(0.742-0.99)and 0.743(0.574-0.960),and P value were 0.013,0.036 and 0.023.In < 55 years groups,females,non-smokers and non-drinkers,TGFBR3 rs1473488 C>T variation was negatively correlated with the incidence of hypertension,the adjusted HRs(95% CIs)of the additive model were 0.705(0.55-0.903),0.821(0.689-0.979),0.783(0.672-0.913)and 0.835(0.718-0.971),and P valuewere 0.006,0.028,0.002 and 0.019.In non-smokers and non-drinkers,the incidence risk of hypertension in CG/GG genotype carriers of TGFBR3 rs6604060 were significantly lower than that in CC genotype carriers,the adjusted HRs(95% CIs)of the dominant model were 0.807(0.668-0.975)and 0.821(0.681-0.990),and P value were 0.026 and 0.030.The follow-up study of stroke found that in the whole population,the incidence risk of ischemic stroke in TT genotype carriers of TGFBR1 rs10512263 was significantly higher than that in CC/CT genotype carriers,after adjustment for age,gender,diabetes,TC,TG,BMI,LDL-C,hypertension,HDL-C,smoking status,and drinking status,HR(95%CI)of recessive model was 1.888(1.167-3.054),and P value was 0.010.The incidence risk of ischemic stroke in GG genotype carriers of TGFBR2 rs3773645 was significantly higher than that in CC/CG genotype carriers,the adjusted HR(95%CI)of recessive model was 1.586(1.043-2.413),and P value was 0.031.TGFBR3 rs1805110 G>A and TGFBR3 rs2799522 G>C variations were significantly associated with decreased incidence risk of stroke,the adjusted HRs(95% CIs)of the additive model were 0.786(0.633-0.976)and 0.684(0.548-0.854),and P value were 0.029 and 0.001,after Bonferroni correction,the association of rs2799522 with IS still reach statistical significance(0.001*37).TGFBR3 rs1804506 T>C and TGFBRAP1 rs17030766 A>G variations were significantly associated with increased incidence risk of stroke,the adjusted HRs(95% CIs)of the additive model were 1.270(1.031-1.564)and 1.506(1.177-1.928),and P value were 0.025 and 0.001,after Bonferroni correction,the association of rs17030766 with IS still reach statistical significance(0.001*37).In the hypertension case-control syudy,the Likelihood ratio test and MB-MDR were used to analyze gene-gene interaction,after adjustment for age,gender,TC,TG,HDL-C,LDL-C,GLU,BMI,smoking and alcohol consumption,the results showed that TGFBR2 rs764522 and TGFBR1 rs1888223(P=0.011),TGFBR2 rs6785358 and TGFBR1 rs1888223(P=0.006),TGFBR2 rs764522 and TGFBR2 rs3773661(P=0.014),TGFBR3 rs12032588 and TGFBR2 rs749794(P=0.008),TGFBR3 rs284878 and TGFBR2 rs6785358(P=0.048),TGFBRAP1 rs2241797 and TGFBR2 rs764522(P=0.032),TGFBRAP1 rs2241797 and TGFBR3 rs284878(P=0.009),TGFBR3rs284878 and TGFB1 rs13168506(P=0.012),TGFBR3 rs284878 and TGFBR2 rs6785358(P=0.016),TGFBR2 rs764522 and TGFBR2 rs749794(P=0.026),TGFBR2 rs764522 and TGFB1 rs13168506(P=0.029),TGFBR3 rs12032588 and TGFB1 rs13168506(P=0.037)had significant interaction on hypertension.In addition,the Likelihood ratio test identified TGFBR3 rs12032588 main effect on hypertension(P=0.018).In the hypertension follow-up study,the multiplicative interaction analysis showed the TGFBR2 rs3773645 and drinking,TGFBR3 rs1473488 and drinking had positive interactions on hypertension incidence after adjustment for sex,age,BMI,TC,TG,diabetes,HDL-C,LDL-C,and smoking,the P values for interaction were 0.024 and 0.028.In addition,TGFBR3 rs1473488 and smoking had positive interactions on hypertension incidence(P<0.001).ConclusionsThese finding suggest that TGFB1 gene,TGFBR1 gene,TGFBR2 gene,TGFBR3 gene and TGFBRAP1 gene genetic variation may be associated with hypertension and stroke in southern Chinese Han population.Moreover,the TGFBR2 rs3773645 and drinking,TGFBR3 rs1473488 and drinking,TGFBR3 rs1473488 and smoking had positive interactions on hypertension incidence and there are significant gene-gene interactions between TGF-beta1 signaling pathway genes multiple SNPs.The elevation of plasma TGF-?1 is closely related to hypertension and stroke,indicated that abnormal expression of TGF-?1 plays an important role in the development of hypertension and stroke. |
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