PRMT3-mediated FOXO1 arginine methylation exacerbates oxidative stress-induced decidualization defects in the eutopic endometrium of endometriosis.

Endometriosis is a hormone dependent disease that often accompanies infertility. At present, the incidence rate of endometriosis is on the rise, but its pathogenesis and the mechanism leading to fertility reduction are still unclear. Here, we report that protein arginine methyltransferase 3 (PRMT3) is crucial for endometriosis. PRMT3 damages the decidualization of stromal cells in endometriosis. Mechanistically, PRMT3 interacts with Forkhead Box O1 (FOXO1) to mediate methylation of its arginine site at position 253, and promotes its degradation while inhibiting its nuclear translocation. Interestingly, the arginine methylation of FOXO1 by PRMT3 inhibits decidualization through oxidative stress. Furthermore, in our animal experiments, we find that SGC707, a PRMT3 inhibitor, inhibits the occurrence of endometriosis, promotes deciduoma formation, and improves embryonic development. Taken together, PRMT3 may be a promising target for treating endometriosis and improving infertility related to endometriosis.