Association Between Osteoponin TagSNPs And The Susceptibility And Clinical Phenotype Of Coronary Artery Disease

Background:Coronary artery disease(CAD)is a complex disease involving the genetic and envirometnal factors,which brings serious human health and economic hazards.With the development of molecular biology,study at the gene level has become a hotspot for pathogenic mechanism of coronary artery disease.Many genetic polymorphisms have been documented to be associated with the disease risk.Candidate-gene association study based on single nucleotide polymorphism(SNP)is an effective strategy for exploring the genetic etiology of complex disease.The secreted protein,acidic and rich in cysteine(SPARC),also named osteonectin,was previously found to be associated with organ development,tissue remodeling,tissue repair and cellular proliferation.This protein could be excreted by multiple organs and its expression in blood circulation is excreted by adipocyte.Recent researches found that SPARC was closely related to coronary artery disease.Moreover,it was associated with the independent risk factors of coronary artery disease like obesity and diabetes mellitus.However,so far there is no study that focus on the relationship between SPARC genetic polymorphisms and the risk of coronary artery disease.Objective:Coronary artery disease is a complex disease,which involves the genetic and envirometnal factors.SPARC(secreted protein acidic and rich in cysteine,also known as osteonectin)plays an important role in regulating the development of coronary artery disease and its most common complication,type 2 diabetes mellitus.So far no study has reported the relationship between the genetic variations of SPARC and the susceptibility of coronary disease.In this study,we selected and detected tagging single nucleotide polymorphisms(tagSNP)that captured at least 80%common genetic polymorphisms of SPARC.The association between SPARC tagSNP and coronary disease susceptiblity and its complication and other clinical phenotypes were analyzed,thereby assessing the risk and severity of coronary disease.Materials and Methods:1.Recruitment of study subjects:According to the design strategy of a case-control,we recruited 107 in-patients with coronary artery disease and 125 healthy controls for genotype detection.The peripheral blood and corresponding clinical information of each study subject was collected.2.Selection of gene polymorphisms:A two-step strategy was employed for the tagging-SNPs(tagSNPs)selection and function prediction.First,we used Haploview to minimize the number of SNPs of SPARC gene from the HapMap Databse,considering that it provides an important shortcut to carry out candidate-gene association study in a certain population.Second,we used online software to prioritize the tagSNPs for genotyping based on their predicted functional effects.3.DNA extraction and genotyping of tagSNPs:Genomic DNA was isolated from peripheral blood lymphocytes by the routine phenol-chloroform method.For the candidate-gene association study,each DNA sample was diluted to working concentrations of 50ng/?l for genotyping.Genotyping of 5 tagSNPs of SPARC were performed by Kompetitive Allele Specific PCR(KASP)technique according to the manufacturer's instructions.4.Statistical analysis:The association strength between genotype and disease risk were presented by Odds ratio(OR)and their corresponding 95%Confidential interval(CI).The ORs and 95%CIs were calculated by multivariate logistic regression adjusted by sex and age.A linear weight of 0,1,or 2 was applied for each genotype containing 0,1,or 2 risk alleles,respectively.For the correlation analysis between each SNP and the number of Interventional vascular number and other risk factors,the Spearman's correlation analysis was employed.Results:1.A total of five tagSNP were included in this study.For the association analysis between a single SNP and the risk of coronary artery disease,no statistical association was found.2.The coronary artery disease patients carrying rs1054204 GC genotype were more likely to occurring type 2 diabetes mellitus,with a 3.10-fold higher risk than the noncarriers(P = 0.048).Additionally,the risk for type 2 diabetes mellitus development in rs3549 GC carriers was 3.86-fold higher than noncarriers(P = 0.029).3.The coronary artery disease patients carrying CCTAC haplotype have a 10.56-fold higher risk for developing type 2 diabetes mellitus than noncarriers.4.For the analysis of the severity of coronary artery disease,the number of variant alleles of rs1054204,rs3210714 and rs3549 was positively related with the interventional vascular umber,indicting a more serious disease that occurs in the carrier with rs1054204,rs3210714 and rs3549 variant alleles.Conclusions:The coronary artery patient carring SPARC rs1054204 GC,rs3549 GC genotypes or CCTAG haplotype conferred higher risk for developing type 2 diabetes mellitus.Moreover,variant alleles for rs1054204,rs3210714,and rs3549 polymorphisms were positively related to the number of affected coronary arteries in coronary artery disease patients,indicating the progression of a more severe coronary disease.