Single-Cell RNA Sequencing Reveals That C5AR1 in Follicle Monocyte Cells Could Predict the Development of POI

Ying Han, Junrong Diao, Xinyan Wang, Shuai Zhang, Lina Yuan, Yaqiong Ping, Yunshan Zhang, Haining Luo Tianjin Central Hospital of Obstetrics and Gynecology/Nankai University Affiliated Maternity Hospital, Tianjin Key Laboratory of Human Development and Reproductive Regulation, Tianjin, 300100, People’s Republic of ChinaCorrespondence: Haining Luo, Tianjin Central Hospital of Obstetrics and Gynecology/Nankai University Affiliated Maternity Hospital, Tianjin Key Laboratory of Human Development and Reproductive Regulation, No. 156 Sanma Road, Nankai District, Tianjin, 300100, People’s Republic of China, Email [email protected]: To investigate the follicle microenvironments of women with premature ovarian insufficiency (POI), with normal ovarian reserve function, and who are older (age > 40 years) and to identify potential therapeutic targets.Patients and Methods: In total, 9 women who underwent in vitro fertilization(IVF) or intracytoplasmic sperm injection(ICSI) were included in this study. The first punctured follicle of each patient was used. Single-cell RNA sequencing was subsequently performed to explore the characteristics of the follicle microenvironments of women with POI, with a normal ovarian reserve and who were older.Results: In total, 87,323 cells were isolated and grouped into six clusters: T cells, B cells, neutrophils, basophils, mononuclear phagocytes (MPs), and granulosa cells. The study demonstrated that the POI samples had a smaller component ratio of MPs than did the other samples. The correlation between MPs and granulosa cells may lead to the development of POI. We found that the gene that was simultaneously downregulated in the POI group compared with the normal and older age groups was HLA-DRB5. Moreover, we observed that HLA-DRB5 was expressed mainly in monocytes. The temporal differentiation trajectory revealed that different monocytes play important roles in the beginning and end stages of differentiation. The C5AR1 gene is highly expressed in monocytes.Conclusion: Our findings revealed that the interaction between monocytes and granulocytes may contribute to the development of POI. We found that POI lacked HLA-DRB5 expression and had impaired antigen processing and presentation activities. To a certain extent, C5AR1 could be used to predict the development of POI.Keywords: single-cell RNA sequencing, follicle microenvironment, premature ovarian insufficiency, inflammation, C5AR1