Hepatocyte-Specific GSDMD Deficiency Aggravates Sepsis by Disrupting Non-Canonical Secretion of Anti-Inflammatory Factors.

Abstract

Gasdermin D (GSDMD)-mediated pyroptosis in macrophages plays a clear role in promoting inflammation and mortality in sepsis. The liver is a commonly damaged organ during sepsis and also an important organ for releasing acute response proteins. However, whether pyroptosis occurs and the function of GSDMD in hepatocytes remains unclear. It is surprising to find that hepatocyte-specific GSDMD knockout (GSDMD) mice have significantly reduced survival rates, markedly elevated systemic inflammation, and increased inflammation in the peritoneal cavity and lungs, suggesting that the absence of GSDMD in hepatocytes promotes systemic inflammatory responses. Serum proteomic analysis shows that anti-inflammatory factors such as VEGF-B and Gremlin-1 are significantly reduced in GSDMDmice. Through in vitro and in vivo experiments combined with a constructed full-length GSDMD and a mutant GSDMD plasmid (GSDMD-c.D276A) that cannot be cleaved, VEGF-B and Gremlin-1 are verified to be released from hepatocytes through the pore-forming activity of GSDMD, thus inhibiting the production of inflammatory factors by macrophages. More importantly, hepatocyte-specific replenishment of full-length GSDMD can reverse the exacerbated inflammatory response in GSDMDmice. These findings together establish that hepatic GSDMD plays a key protective role in sepsis by promoting the release of anti-inflammatory factors through pore formation in hepatocytes.