Alteration of Myeloid-Derived Suppressor Cells, Chronic Inflammatory Cytokines, and Exosomal miRNA Contribute to the Peritoneal Immune Disorder of Patients With Endometriosis

Immunologic disorder has been reported to promote the progression of endometriosis (EMT). It has been known that myeloid-derived suppressor cells (MDSCs) drive the progression of many types of diseases. Few studies have shown the relation between MDSCs and EMT. To test whether MDSCs play a role in the progression of EMT, we defined MDSCs, cytokines, and the exosomal microRNA (miRNA) profile in peritoneal fluid (PF) from EMT patients. Characteristics of MDSCs, regulatory T cells (Tregs) and effector T cells were quantified by flow cytometry. Peritoneal fluid monocyte chemoattractant protein (MCP) 1/3, hepatocyte growth factor (HGF), chemokine (C-X-C motif) ligand (CXCL) 1/2, and 13 other cytokines were performed by enzyme-linked immunosorbent assay kit. Exosomal miRNA sequencing was prepared from PF of 3 women with early-stage EMT, 3 women with advanced stage EMT, and 3 women from control group. Our results showed that accumulations of monocytic MDSCs (Mo-MDSCs) and Tregs were detected in advanced patients with EMT. Patients with EMT displayed a significantly higher production of PF CXCL1, CXCL2, MCP-1, MCP-3, and HGF as compared to those from controls. MicroRNA sequencing showed 13 exosomal miRNAs (miRNA-1908, -130b, -451a, -486-5p, -4488, -432, -342, -425, -505, -6508, -145, -365a, and -365b) which are involved in immune alteration and cell proliferation and were differentially expressed in patients with EMT (fold-change ± 2.0). In conclusion, our study revealed that Mo-MDSCs, inflammatory cytokines, and exosomal miRNA seem to be involved in the progression of EMT; however, the relation between Mo-MDSCs, cytokines, and miRNA needs further research.