The Molecular Mechanism Of The Association Between ANXA5, KDR Gene Promoter Single Nucleotide Polymorphisms And The Unexplained Recurrent Spontaneous Abortion

Objective: To explore the molecular mechanism of the association between annexin A5(ANXA5)and kinase insert domain receptor(KDR)gene promoter single nucleotide polymorphism(SNP)and unexplained recurrent spontaneous abortion(URSA)in Chongqing and to elucidate the molecular process of URSA induced by high-risk mutations of candidate genes,resulting in endothelial injury of umbilical cord and thrombosis.We want to establish and improve the clinical model of URSA caused by hereditary thrombosis risk,develop a sound diagnosis and treatment guide and a safe and reliable clinical intervention program for the patients at the same time.Methods: 142 patients with URSA who were not pregnant,and 107 healthy women were enrolled in this study.A controlled trial was conducted to examine the association between genetic promoter SNPs and genetic risk of URSA.The effects of SNPs of gene promoter on gene transcription activity were verified by double-luciferase detection of recombinant plasmids of different genotypes.Using bioinformatics method to predict whether the two-dimensional structure changes and the specific transcription factors.Results: The frequency of mutated homozygote alleles of ANXA5(rs1050606)and KDR(rs55713360)were increased markedly in the case group.And the G allele in rs1050606 loci was the risk factor of URSA while the T allele decreased the risk of disease.The C allele in rs55713360 loci was the risk factor of URSA while the T allele decreased the risk of disease.A total of 6 recombinant plasmids for different genotypes were successfully constructed(6 sites with total wild homozygosity,total mutation homozygosity,and single locus mutation homozygosity at the remaining loci).The dual luciferase reporter systems of ANXA5 and KDR genes showed a significant decrease in transcriptional activity in the upstream regulatory sequence of mutant genotypes promoter compared with wild type.It is predicted that the four transcription factors of ZBTB33,RELA,INSM1 and REL may be combined with ANXA5(rs1050606).TEAD4,NOTO,VSX1 may be combined with KDR(rs55713360),and the molecular two-dimensional structure has changed.Conclusion: The mutant genotypes of ANXA5(rs1050606)and KDR(rs55713360)significantly increased the genetic risk of URSA as a risk factor.SNPs of the promoter of ANXA5 and KDR genes inhibited the transcription activity of the gene,possibly due to the change of the advanced structure of the gene.