Emestrin-Type Epidithiodiketopiperazines Inhibited Gasdermin D-Mediated Pyroptosis via Caspase-3/7 Activation

Area of Science:

• Biochemistry
• Immunology
• Pharmacology

Background:

• Sepsis involves a dysregulated host response to infection, often worsened by pyroptosis, a pro-inflammatory cell death pathway.
• Gasdermin D (GSDMD) activation is central to pyroptosis, leading to pore formation and inflammation.

Purpose of the Study:

• To identify inhibitors of GSDMD cleavage during pyroptosis.
• To evaluate the therapeutic potential of emestrin-type epidithiodiketopiperazines (ETPs) in sepsis models.

Main Methods:

• High-throughput screening identified ETPs as GSDMD cleavage inhibitors.
• Surface plasmon resonance and western blotting confirmed ETPs activate caspase-3/7, cleaving GSDMD.
• In vivo studies utilized lipopolysaccharide (LPS)-induced shock and cecal ligation and puncture (CLP) models.
• Single-cell RNA sequencing (scRNA-seq) analyzed murine lung tissue responses.

Main Results:

• ETPs were identified as potent inhibitors of GSDMD cleavage, preventing pyroptosis.
• ETPs activate caspase-3/7, leading to GSDMD cleavage at Asp87, generating a p10 fragment and inhibiting pore formation.
• Compound 2, a lead ETP, protected against lethal LPS-induced septic shock and reduced lung inflammation.
• In the CLP model, compound 2 significantly improved survival by reducing GSDMD-positive neutrophil and monocyte infiltration.
• scRNA-seq revealed compound 2 suppressed LPS-induced inflammation by inhibiting monocyte-derived dendritic cell (moDC) maturation.

Conclusions:

• ETPs effectively target GSDMD-driven pyroptosis, offering a novel therapeutic strategy for sepsis.
• Compound 2 shows significant promise for clinical translation in treating sepsis by mitigating inflammation and improving survival.