CD11c+ M1-like macrophages (M\u03a6s) but not CD206+ M2-like M\u03a6 are involved in folliculogenesis in mice ovary

Gentaro Izumi,Hideki Hatta,Johji Imura,Tomoyuki Fujii,Hirofumi Nishizono,Allah Nawaz,Yutaka Osuga,Kaori Koga,Akitoshi Nakashima,Osamu Yoshino,Yosuke Ono,Shigeru Saito,Kazuyuki Tobe,Miwako Nagai

doi:10.1038/s41598-018-25837-3

Abstract

Macrophages (MΦs) are involved in folliculogenesis and ovulation. However, it is unknown which type of MΦ, M1 or M2, plays a more essential role in the ovary. CD206 or CD11c diphtheria toxin receptor transgenic (DTR) mice, which enable depletion of CD206+ M2 MΦs and CD11c+ MΦ or CD11c+ Dendritic cells (DCs), respectively, were used. Oocytes were used for in vitro fertilization and embryo transfer. In vitro fertilized embryos derived from M2 MΦ depleted oocytes were transferred to pseudo pregnant wild type mice. CD11c DTR mice were also used to investigate the role of CD11c cells, M1 MΦ and DCs in folliculogenesis. In WT mice, the proportion of CD206+ M2-like MΦs was not increased in follicular induction, while that of CD11c+ M1-like MΦs was increased. In CD206 DTR mice, folliculogenesis was normal and the ovulation number, fertilization rate, and implantation rate were similar to those in WT mice. In CD11c DTR mice, folliculogenesis was impaired with ovarian hemorrhage and the staining of platelet derived growth factor-receptor β (PDGF-Rβ), a marker of pericytes, and CD34, a marker of endothelial cells, was reduced. CD11c+ cells, M1 MΦs or DCs, may be involved in folliculogenesis, while M2 MΦs are not involved in folliculogenesis.

Highlights

Macrophages (MΦs) are immune cells derived from bone-marrow precursors, and the differentiation of MΦs occurs in response to the surrounding cytokine milieu for acquisition of tissue-specific phenotypes[1]
In wild type mice (WT) ovary, M1 and M2 MΦs were detected by flow cytometry (Fig. 1a) and flow cytometry analysis revealed that the proportion of CD11c+ F4/80+ M1-like MΦs was significantly increased in the ovary (P < 0.05, Fig. 1b, left panel), while the proportions of CD206+ F4/80+ M2-like MΦs (Fig. 1b, middle panel) and CD11c+ F4/80-DCs (Fig. b, right panel) were not increased
In CD206 diphtheria toxin-receptor (DTR) mice treated with PMSG for 48 h (Supplemental Fig. 2), in which M2 MΦs were depleted, the morphology of ovary was not changed compared to WT (Fig. 2b)

Summary

Introduction

Macrophages (MΦs) are immune cells derived from bone-marrow precursors, and the differentiation of MΦs occurs in response to the surrounding cytokine milieu for acquisition of tissue-specific phenotypes[1]. The CD11b diphtheria toxin-receptor (DTR) transgenic mouse model, a novel method of pan-MΦs ablation, has been used for various disease studies to investigate the role of MΦs21–23. In this mouse model, diphtheria toxin (DT) administration results in rapid and near complete ablation of pan-MΦs. Resulted in ovarian hemorrhage with endothelial cell depletion and follicular atresia[24] These hemorrhages were not observed in other tissues, suggesting that MΦs play a critical role in maintaining ovarian vascular integration during folliculogenesis. Through the accumulation of knowledge obtained from the CD206+ M2 MΦ and CD11c+ M1 MΦ and DC depletion models, and by comparing these data to CD11b DTR mouse data, we further investigated the role of MΦs in folliculogenesis

Methods

Results

Conclusion