Objective To explore the role and possible mechanisms of bone marrow mesenchymal stem cell (BMSC) in the lipopolysaccharide (LPS)-induced inflammatory response involving alveolar macrophages through the inflammatory pathways. Methods ptges and ptges shRNA were transfected into BMSC by lentivirus, and stable ptges overexpression BMSC (BMSC-PGE2(+)) and PTGEs silencing BMSC (BMSC-PGE2(-)) were established. Macrophages were divided into control group, LPS group, LPS+BMSC group, LPS+BMSC-PGE2(+) group and LPS+BMSC-PGE2(-) group. The expression levels of nucleotide-bound oligomerized domain-like receptor 3 (NLRP3), precursor cysteinyl aspartate specific proteinase 1 (pro-caspase-1), caspase-1 and pro-IL-1β proteins were detected by Western blot. The mRNA expression levels of NLRP3 and caspase-1 were determined by RT-PCR. The expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-10, IL-18 and prostaglandin E2 (PGE2) in cell supernatant were detected by ELISA. Results The intervention of LPS significantly increased the expression of NLRP3, pro-caspase-1, caspase-1 and pro-IL-1β in macrophages. After co-culture with BMSC, the expression of each protein decreased significantly. After the overexpression of PGE2, the difference of protein expression further decreased. The expression of NLRP3 and caspase-1 mRNA in LPS group increased significantly, but decreased significantly after co-culture with BMSC. Overexpression of PGE2 could increase this difference, but there was no significant change in PGE2 silent group. The results of ELISA showed that the contents of TNF-α, IL-1β and IL-18 in cell supernatant were the highest in LPS group. Adding BMSC and overexpressing PGE2 could decrease the related inflammatory factors. The levels of IL-10 and PGE2 in LPS group were higher than those in control group, and further increased in LPS+BMSC group and LPS+BMSC-PGE2(+) group with significant differences. Conclusions When inflammation is induced by LPS, BMSC can significantly mitigate the inflammatory response within macrophages. This process is likely mediated through the overexpression of PGE2, which inhibits the NLRP3-mediated pyroptosis pathway.