Application Of ATAC-seq In The Research Of Decidual Endometrial Stromal Cells

The decidual tissue is a special tissue formed by proliferation and re-differentiation of endometrial stromal cells under the stimulation of decidualization-inducing factors.Decidualization is essential for the establishment and maintenance of pregnancy.Elegant expression of decidual function-related genes is central to embryo implantation,pregnancy establishment and maintenance,and parturition.Chromatin accessibility represents the ability of chromatin DNA binding to other molecules,such as transcription factors,and is closely related to gene expression levels.At present,molecular mechanisms related to decidualization has been widely carried out,related transcription factors and signaling pathways have been discovered,however,the chromatin reorganization during decidualization are still not clear.In this experiment,we use in vitro induced decidualization model of endometrial stromal cells,integrating with ATAC-seq,Ch IP-seq and RNA-seq high throughout sequencing,to explore the chromatin reconstruction,distribution characteristics of H3K4me3 and H3K27me3,gene expression of transcription factors and the interplay communication between these data during the process of decidualization.In this experiment,167940 and 166699 ATAC-seq peaks were mapped in undifferentiated and decidualized endometrial stromal cells by performing ATAC-seq.The ATAC-seq peaks of undecidualized or decidualized endometrial stromal cell were all enriched in promoters,introns and distal intergenic region.Histone modifications,H3K4me3 and H3K27me3,are also enriched in the promoter,intron and distant intergenic regions,while the most abundant region of H3K4me3 is the promoter region,while H3K27me3 is mostly enriched in the distal intergenic region.Chromatin accessibility of a large number of loci has changed significantly.By RNA-seq analysis of endometrial stromal cells,it was found that decidualization of endometrial stromal cells lead to significant changes in gene expression.By comparing the chromatin accessibility and m RNA expression levels of decidualized endometrial stromal cells,it was found that chromatin accessibility was positively correlated with m RNA expression levels.The comparison of chromatin accessibility and histone modification in decidualized endometrial stromal cells showed that chromatin accessibility was positively correlated with the recruitment of H3K4me3 and strongly negatively correlated with the recruitment of H3K27me3.In order to reveal the relationship among chromatin accessibility,H3K4me3,H3K27me3 histone modification and decidual gene expression,data was integrated to gene regions of decidualization marker molecule IGFBP1,PRL and non-coding RNA LINC473.Results show that ATAC-seq peak was significantly enriched in the promoter regions of IGFBP1,PRL and LINC473,while H3K4me3 was only enriched in the promoter regions of IGFBP1 and LINC473.Finally,we mined and verified 8 molecules with significant changes in chromatin accessibility from ATAC-seq data.Performing RNAi,it was found that defect of CEBPD expression leads to impede decidualization of endometrial stromal cells with reduction of the expression of IL-11,a key molecule of decidualization.To summarize,in this study,the chromatin accessibility and histone modification of H3K4me3,H3K27me3 during decidualization have been clarified;the relationships among chromatin accessibility,histone modification H3K4me3,H3K27me3 and decidual gene expression have been elucidated;8 molecules with significant changes in chromatin accessibility in decidualized endometrial stromal cells have been verified;furthermore,the function of CEBPD,which is one of 8 molecules,in decidualization has been proved.