Study On The Mechanism Of Unexplained Recurrent Spontaneous Abortion Based On Methylation And Expression Microarray

ObjectiveRecurrent miscarriage,also referred to as habitual abortion,is defined as two or more consecutive pregnancy losses.Recurrent miscarriagecan be physically and emotionally taxing for couples and seriously threatened the harmony of the family.The incidence of recurrent spontaneous abortion is about 1～5%of women of bearing ages.The known etiologies of recurrent abortion include genetic disorders,anatomic abnormalities,endocrine disorders,thrombotic etiologies and immunologic abnormalities.However,approximately half of all cases remain unexplained which brings great difficulties to the treatment.With the development of high-throughput sequencing and gene expression microarray technology,researchers could have a more comprehensively understanding of the changes in gene expression profiles and methylation sites in certain diseases.This technology had been widely used in screening tumor markers and prognostic gene.This study intends to analyze the methylation and expression profile of patients with unexplained recurrent miscarriage in the GEO database to explore new pathogenic mechanisms in unexplained recurrent miscarriage.MethodsIn this study,R and Perl language were used for GEO data processing and differential expressed gene analysis.The abnormal regulation of miRNA was closely related to the occurrence of many diseases.Transmir v2.0 was a database of 3730TF-miRNAs from 19 species and 1.7 million TF-miRNAs from ChIP-seq.MiRNA could inhibit the target gene with important function by binding to the 3’-UTR region.Transmir v2.0 could predict the transcription factors that have regulatory relationship with miRNA through the binding sequence of miRNA and transcription factors.Mirwalk 2.0 was the largest database that provides a set of predictive,experimentally confirmed miRNA target interactions in a variety of novel ways.We used Cytoscape to map the regulatory network of TF-miRNA-mRNA.R language limma package was used for differential methylation site analysis.ResultsA total of 278significantly differentially expressed mRNAs were obtained from GSE121950 meeting the screening conditions of│log₂ Fold change│>2 and P<0.01.Thrity-four differentially expressed miRNAs were acquired from GSE73025satisfying the screening conditions of│log₂ Fold change│>1 and adj P<0.05.A total of 25 different methylation sites corresponding to 25 differentially expressed mRNAs were obtained from GSE43256,which met the filter conditions of│log₂ Fold change│>0.1 and adj P<0.05.We constructed the regulatory network of TF-miRNA-mRNA and obtained 25 methylation driven genes and 25 hypomethylated and hyperexpressed genes.ConclusionGATA1-MIR149-DDX1,NELFE-MIR4505-CORO2A and SMC3-MIR181d-BCL11A might play an important regulatory role in unexplained recurrent abortion.The methylation levels of ASL,DNASE1L3 and WNT7A also affected the occurrence and development of unexplained recurrent spontaneous abortion.We need further experimental verification.This study systematically revealed the regulatory relationship of miRNA and methylation in unexplained recurrent spontaneous abortion through a large number of data analysis,which provided new ideas for clarifying the mechanism of unexplained recurrent spontaneous abortion.