Caffeic acid, but not ferulic acid, inhibits macrophage pyroptosis by directly blocking gasdermin D activation

Abstract

Regulated pyroptosis is critical for pathogen elimination by inducing infected cell rupture and pro‐inflammatory cytokines secretion, while overwhelmed pyroptosis contributes to organ dysfunction and pathological inflammatory response. Caffeic acid (CA) and ferulic acid (FA) are both well‐known antioxidant and anti‐inflammatory phenolic acids, which resemble in chemical structure. Here we found that CA, but not FA, protects macrophages from both Nigericin‐induced canonical and cytosolic lipopolysaccharide (LPS)‐induced non‐canonical pyroptosis and alleviates LPS‐induced mice sepsis. It significantly improved the survival of pyroptotic cells and LPS‐challenged mice and blocked proinflammatory cytokine secretion. The anti‐pyroptotic effect of CA is independent of its regulations in cellular lipid peroxidation, mitochondrial function, or pyroptosis‐associated gene transcription. Instead, CA arrests pyroptosis by directly associating with gasdermin D (GSDMD) and blocking its processing, resulting in reduced N‐GSDMD pore construction and less cellular content release. In LPS‐induced septic mice, CA inhibits GSDMD activation in peritoneal macrophages and reduces the serum levels of interleukin‐1β and tumor necrosis factor‐α as the known pyroptosis inhibitors, disulfiram and dimethyl fumarate. Collectively, these findings suggest that CA inhibits pyroptosis by targeting GSDMD and is a potential candidate for curbing the pyroptosis‐associated disease.

The gasdermin family: emerging therapeutic targets in diseases

“… 45 , 52 , 383 , 384 , 514 , 516 – 519 . ~10 μM Modifying Cys191 of GSDMD and inhibiting the oligomerization of GSDMD-NT Modifying Cys133 in the TLR-binding partner MD-2 and preventing LPS recognition; Inhibiting NLRP3 signaling LPS/CLP-induced sepsis, ulcerative colitis, AS, obesity and metabolic dysfunction, SARS-CoV-2 infection, ARDS, DN, NAFLD Dimethyl fumarate (DMF) 46 , 409 <10 μM Succinating Cys191 of GSDMD, blocking caspase-GSDMD interactions and inhibiting the oligomerization of GSDMD-NT Succinating GSDME at Cys45; dopamine beta-hydroxylase; caspase-1; caspase-3 LPS-induced sepsis, FMF, EAE, HCC Itaconate 320 , 523 , 531 – 533 Not known Binding to GSDMD via Cys77 and blocking caspase-GSDMD interactions Inhibiting NLRP3 and caspase-1 ARDS, IBD, LPS-induced sepsis C202-2729 503 Not known Binding directly to the GSDMD-NT and inhibiting the oligomerization of GSDMD-NT Not known EAE Caffeic acid (CA) 522 Not known Binding directly to GSDMD and blocking GSDMD cleavage Not known LPS-induced sepsis GSDMD inhibitor Y1 (GI-Y1) 445 Not known Binding to GSDMD via Arg7 and inhibiting the oligomerization of GSDMD-NT Not known Myocardial I/R injury AD Alzheimer’s disease, AS atherosclerosis, ALF acute liver failure, ARDS acute respiratory distress syndrome, CLP cecum ligation and puncture, DN diabetic nephropathy, EAE experimental autoimmune encephalomyelitis, FMF familial Mediterranean fever, HCC hepatocellular carcinoma, IBD inflammatory bowel disease, I/R ischemia/reperfusion, LPS lipopolysaccharide

Fig. 5 Strategies for managing GSDMD-related disorders.

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“…In addition to inhibiting GSDMD, DMF also succinates GSDME at the Cys45 site to block GSDME cleavage and GSDME-dependent pyroptosis. DMF has been used across a spectrum of animal models of inflammatory diseases to reduce the severity, including LPS-induced sepsis, 46 , 522 FMF, 46 EAE, 46 and HCC. 409 …”

“…They found that caffeic acid (CA) inhibited canonical pyroptosis and non-canonical pyroptosis, contributing to the mitigation of LPS-induced sepsis in mice. 522 The inhibitory effect of CA on pyroptosis is not contingent upon its influence on cellular lipid peroxidation, mitochondrial functionality, or the expression of genes pertinent to pyroptosis. Mechanistically, CA prevents pyroptosis by directly binding to and blocking the processing of GSDMD, thereby diminishing the formation of GSDMD pores and the subsequent release of cellular contents.…”