PTGDS and infection: Our findings demonstrate the different roles of exogenous PGD2 throughout the infection process and its molecular mechanisms (Figure 9): in the early stages, PGD2 enhances the inflammatory response, while later, it increases the bactericidal capacity of BMDMs against E. coli by reducing pro-inflammatory cytokines and chemokines, promoting anti-inflammatory factor production, and decreasing DAMPs expression, ultimately alleviating endometrial damage.