Bioinformatics analysis of granulosa cells in PCOS patients based on single-cell sequencing data
Objective:To investigate the effect of differentially expressed genes(DEGs)in granulosa cells on the pathogenesis of PCOS.Methods:PCOS infertility patients who underwent ICSI for pregnancy assistance at Department of Reproductive Medicine,First Affiliated Hospital of Hainan Medical College from June to October 2022 were recruited as study group(n=5),and patients with normal ovarian function during the same period were used as control group(n=5).The discarded follicular fluid after oocyte retrieval was collected and granulosa cells were extracted for single-cell RNA sequencing(sc RNA-seq).The bioinformatics software Single R package was used to predict the cell type,the volcano map of granulosa cell DEGs was developed by Ggplot2 package,and GO functional enrichment and KEGG pathway analysis were performed.Then,String online database(http://string-db.org)was applied to construct protein-protein interaction(PPI)network maps of DEGs,MCODE and CytoNCA plug-ins in Cytoscape(3.9.1)software were used for visual analysis of the DEGs,and GEO database was applied to validation of DEGs.Results:Single-cell RNA-seq results showed that 9 017 unique DEGs were screened in the PCOS group when compared with the control group,of which 49 genes were significantly up-regulated and 25 genes were significantly down-regulated.GO enrichment analysis showed that differentially differentiated genes were mainly enriched in cytoplasmic translation and wound healing in terms of bioprocess(BP),adherence plaques and cytoplasmic ribosomes regarding cellular components(CC),and structural components of ribosomes and calcium adhesion protein binding in terms of molecular function(MF).KEGG pathway analysis showed that the differential genes were mainly enriched in signaling pathways such as coronavirus disease(COVID-19),ribosomes,ovarian steroidogenesis and so on.Conclusions:This study reveals that granulosa cells in infertile women with PCOS may be affected by steroidogenesis,metabolism,inflammation,and oxidative stress,providing ideas for the pathogenesis of PCOS and the development of clinically relevant therapeutic strategies.