Gene Polymorphism And Cardiovascular Disease Related Research In The Microrna Binding Sites

Cardio-cerebral vascular disease is the leading cause of morbidity and mortality. Stroke is a main type of the cardio-cerebral vascular diseases.Importantly,stroke is the No.1 causes of disability in china.Many factors could contribute stroke,such as aging,smoking,drinking,hypertension,hyperlipidemia,hyperglycemia,heart diseases,and blood coagulation mechanism obstacles.In addition,genetic factors have been shown to play an essential role in the pathogenesis of stroke.The genetic markers of stroke susceptibility are helpful for the prediction and prevention of stroke.Stroke evolves depending on the accumulation of risk factors which leads to atherosclerotic lesions.The role of angiogenesis within diseased blood vessels has emerged as a hotspot debate in the biology of atherosclerosis and arterial diseases.Angiopoietin 1(ANGPT1) is a vascular endothelial cell growth factors and the ligand for Tie2,a tyrosine kinase receptor.ANGPT1 plays a critical role in angiogenesis,it can promote blood vessel remodeling and maturing,prevent apoptosis of endothelial cells,and maintain the integrity of blood vessels and recovery function of vascular injury.We can speculate that the expression of ANGPT1 may be associated with vascular disease,including stroke.Based on the literature and database enquiries,SNP+1602 A/T in the 3'-UTR of ANGPT1 was found in the region for microRNA recognition for binding.Variations in this region could influence microRNA binding to the mRNA of ANGPT1 and change ANGPT1 expression. Therefore,we hypothesized that SNP+1602 A/T could influence ANGPT1 expression and are associated with stroke.To test our hypothesis,we first determined whether the SNP could influence ANGPT1 expression by Luciferase reporter assay.Luciferase reporter vectors containing the SNP were co-transfected into cultured cells with the micorRNA or control.The expression of gene was determined through the double-Luciferase test. Our results showed that expression level of Luciferase reporter vector with SNP A was significantly lower than that of the vector with SNP T(median,74.96 versus 180.82;P＜0.01) in the presence of microRNA.But no significantly change was found in the expression level of Luciferase reporter vector carrying the two SNPs in either the control or blank conditions.Next,we carried out a case-control study in two different Chinese Han populations.SNP+1602A/T was genotyped with polymerase chain reaction-Ligase detection reaction(PCR-LDR).Genotype frequencies fulfilled expectation of Hardy-Weinberg equilibrium.In the first population,1791 cases with stroke(803 cerebral thrombosis,499 lacunar infarctions and 489 intracerebral hemorrhages) and 1843 controls were included.Age and sex were matched between the cases and controls.Our results showed that the frequency of AA genotype was significantly higher in the intracerebral hemorrhage than in the control(41.1%versus 31.9%; P＜0.01).Aider adjustment for age,sex and other conventional risk factors with multiple logistic regression analysis,the AA genotype of ANGPT1+1602 remained independently associated with increased risk for hemorrhagic stroke(odds ratio,3.21; 95%CI,1.45 to 7.11;P＜0.01).In second population,395 cases with stroke(238 ischemic strokes and 157 hemorrhagic strokes) and 790 controls were included.Our results showed that the frequency of AA genotype was significantly higher in the hemorrhagic stroke than in the control(43.3%versus 32.9%;P＜0.01).After adjustment for age,sex and other conventional risk factors with multiple logistic regression analysis,the AA genotype of ANGPT1+1602 was independently associated with increased risk for hemorrhagic stroke(odds ratio,2.45;95%CI,1.34 to 4.50;P＜0.01).In conclusion,our results support that SNP+1602 A/T could influence the expression of ANGPTI by change in the binding of microRNA.Case-control study further showed that +1602 AA genotype conferred significant risk of hemorrhagic stroke.The polymorphism may be a novel genetic marker for the prediction and prevention of stroke,and a new target for the treatment of stroke. Coronary heart Disease is the leading cause of morbidity and mortality in the world.Renin-angiotensin system(RAS) is important in regulation of cardiovascular functions and plays a critical role in pathophysiology of coronary heart disease. AngiotensinⅡ[(AngⅡ) is an important member of RAS system,and performs its functions mainly by AngⅡtype 1 receptor(AT1R).The latest report showed that the SNP rs5186(A1166C) in the 3'-UTR of AT1R can affect mRNA and miR-155 combination.MiR-155 down-regulates the expression of AT1R by the binding with AT1R mRNA in the presence of rs5186 A allele,but not the C allele.The expression of AT1R may be associated with risk of coronary heart disease.Therefore a case-control study was performed to examine whether SNP A1166C correlates with risk of coronary heart disease.A total of 455 patients with coronary heart disease and 465 controls by coronary angiography were recruited.SNP rs5186(A1166C) was genotyped by using allele-specific PCR.Genotype frequencies fulfilled expectation of Hardy-Weinberg equilibrium.Our results showed that the frequency of 1166AA genotype in controls was significant higher than that in patients,(65.4%versus 50.3%;P＜0.01);and AA genotype could reduce the risk of coronary heart disease(odds ratio,0.214;95%CI, 0.084 to 0.548;P＜0.01).We can conclude that the polymorphism of AT1R gene was associated with coronary heart disease,the A allele is a protective factor of coronary heart disease.