Small RNA sequencing revealed aberrant piRNA expression profiles in deciduas of recurrent spontaneous abortion patients

Piwi-interacting RNAs(piRNAs)is a novel class of non-coding RNAs.However,changes in piRNA expression profiles in recurrent spontaneous abortion(RSA)have not yet been investigated.The aim of this study was to identify differentially expressed piRNAs in deciduas of RSA patients.Decidua tissues were collected by curettage from recruited RSA patients and normal early pregnant(NEP)women with their informed consent.Small RNA sequencing was used to evaluate the differences in piRNA expression profiles between RSA and NEP.The present results demonstrated that the counts of total piRNA reads in RSA samples were increased compared with those in NEP samples(0.21%vs.0.11%).Differential expression analysis identified 29 upregulated piRNAs and 18 downregulated piRNAs in RSA samples.RT-qPCR further confirmed that the expression levels of uniq-109625,uniq-89328,uniq-50651 and uniq-4569 were decreased in 8 RSA tissues,compared with 13 NEP tissues.Otherwise,pi-22628 and uniq-173406 were increased in 8 RSA tissues.Based on GO term and KEGG pathway analysis,we speculate that these piRNAs regulate RSA by targeting extracellular matrix component pathway,cell adhesion pathway and focal adhesion pathway.PiRNAs may be involved in RSA pathogenesis by target genes function on adhesion and extracellular matrix component.