Investigation on the mechanism of mafenide in inhibiting pyroptosis and the release of inflammatory factors.

OBJECTIVE

The present study was designed to investigate the roles and mechanism of mafenide (MAF) in targeted inhibition of Gasdermin D (GSDMD) cleavage and in suppressing pyroptosis.

METHODS

Lipopolysaccharide (LPS) and Nigericin were used to induce pyroptosis in mouse bone marrow-derived macrophages (iBMDM) and mouse microglia (BV2). Lactate dehydrogenase (LDH) release rate and Propidium Iodide (PI) uptake rate were used to detect cytotoxicity, Western blot was used to detect the protein expression, and Enzyme-linked immunosorbent assay (ELISA) was utilized to detect the expression of inflammatory factors from culture medium. MAF was labeled with biotin and subsequently subjected to Pull-down assay to detect its binding to GSDMD. GSDMD-Asp275 site was further mutated to validate the binding of MAF to GSDMD. Finally, the effects of MAF on inflammatory factor release and microglial activation were confirmed in the APP/PS12 animal model.

RESULTS

MAF could inhibit pyroptosis in iBMDM and microglia BV2, and decrease the release of inflammatory factors. MAF could inhibit GSDMD cleavage by directly binding to the GSDMD-Asp275 site, while the expression of p30-GSDMD was simultaneously down-regulated and the release of inflammatory factors was decreased. MAF could reduce the levels of inflammatory factors in cerebrospinal fluid and peripheral blood of APP/PS1 mice, and suppress the activation of microglia.

CONCLUSION

The mechanism underlying the regulation of MAF on inflammatory response was correlated with the inhibition of pyroptosis. MAF could inhibit GSDMD cleavage by directly binding to GSDMD.