The gasdermin protein family: emerging roles in gastrointestinal health and disease

Since the identification and characterization of gasdermin (GSDM) D as the main effector of inflammatory regulated cell death (or pyroptosis), literature on the GSDM family of pore-forming proteins is rapidly expanding, revealing novel mechanisms regulating their expression and functions that go beyond pyroptosis. Indeed, a growing body of evidence corroborates the importance of GSDMs within the gastrointestinal system, underscoring their critical contributions to the pathophysiology of gastrointestinal cancers, enteric infections and gut mucosal inflammation, such as inflammatory bowel disease. However, with this increase in knowledge, several important and controversial issues have arisen regarding basic GSDM biology and its role(s) during health and disease states. These include critical questions centred around GSDM-dependent lytic versus non-lytic functions, the biological activities of cleaved versus full-length proteins, the differential roles of GSDM-expressing mucosal immune versus epithelial cells, and whether GSDMs promote pathogenic or protective effects during specific disease settings. This Review provides a comprehensive summary and interpretation of the current literature on GSDM biology, specifically focusing on the gastrointestinal tract, highlighting the main controversial issues and their clinical implications, and addressing future areas of research to unravel the specific role(s) of this intriguing, yet enigmatic, family of proteins.

Repeated neonatal sevoflurane induced neurocognitive impairment through NF-κB-mediated pyroptosis

Background

Exposure to general anesthesia (GA) during the postnatal period is associated with neuroinflammation and long-term neurocognitive impairment in preclinical and clinical settings. Pyroptosis is a novel type of programmed cell death that, along with inflammation, has been found to play an important role in the mechanism of diverse neurological diseases. However, its roles in GA-induced neuroinflammation and neurocognitive impairment in the developing brain have not been investigated.

Methods

Rats at postnatal day 6 or primary hippocampal neurons at 9 days in vitro received 3% sevoflurane for 2 h daily for three consecutive days. A pharmacological inhibitor of nuclear factor (NF)-κB (BAY 11-7082) was administered to suppress NF-κB activation. Histological and biochemical analyses were performed to assess the pyroptosis as well as neuronal and synaptic damage both in vivo and in vitro. In addition, behavioral tests were performed to evaluate neurocognitive ability in rats.

Results

Repeated sevoflurane exposure activated NF-κB-mediated pyroptosis and neuroinflammation in the hippocampus in developing rats, damaged the neuronal morphology and synaptic integrity, and induced neurocognitive impairment in rats. BAY 11-7082 treatment suppressed the activation of pyroptosis, attenuated the neuronal and synaptic damage, and ameliorated the neurocognitive impairment induced by repeated sevoflurane administration to developing rats.

Conclusions

Repeated sevoflurane GA may induce neuroinflammation and neurocognitive impairment in developing rats via the activation of NF-κB-mediated pyroptosis. Our findings characterize a novel role of pyroptosis as a potential therapeutic target in neuroinflammation after repeated neonatal GA.