Large Peritoneal Macrophages Promote the Resolution of Inflammation in Injured Endometrium.

Macrophages play a significant role in the repair of endometrial injuries. While large peritoneal macrophages (LPMs) have been reported to migrate to injured organs and repair tissues within the peritoneal cavity, their involvement in the repair of injured endometrium remains unclear. In this study, we utilize a mouse model of endometrial injury that does not involve laparotomy, a procedure that typically results in a substantial loss of LPMs. Strikingly, we find that LPMs reach the endometrium within 6 h post-modeling. By depleting or supplementing LPMs, our results reveal that these cells are capable of engulfing dead cells in the endometrium and resolving inflammation. Additionally, we observe that the migration efficiency of LPMs is enhanced with increased levels of 17β-estradiol (E2) in mice. In vitro assays further confirm that E2 accelerates the migration of LPMs towards apoptotic endometrial stromal cells. Overall, our findings demonstrate that LPMs rapidly migrate into injured endometrium in relation to E2 levels and facilitate the process of tissue repair.