Inflammasome-mediated pyroptosis in defense against pathogenic bacteria

Immune modulation for the patterns of epithelial cell death in inflammatory bowel disease

Inflammatory bowel disease (IBD) is an inflammatory disease of the intestine whose primary pathological presentation is the destruction of the intestinal epithelium. The intestinal epithelium, located between the lumen and lamina propria, transmits luminal microbial signals to the immune cells in the lamina propria, which also modulate the intestinal epithelium. In IBD patients, intestinal epithelial cells (IECs) die dysfunction and the mucosal barrier is disrupted, leading to the recruitment of immune cells and the release of cytokines. In this review, we describe the structure and functions of the intestinal epithelium and mucosal barrier in the physiological state and under IBD conditions, as well as the patterns of epithelial cell death and how immune cells modulate the intestinal epithelium providing a reference for clinical research and drug development of IBD. In addition, according to the targeting of epithelial apoptosis and necroptotic pathways and the regulation of immune cells, we summarized some new methods for the treatment of IBD, such as necroptosis inhibitors, microbiome regulation, which provide potential ideas for the treatment of IBD. This review also describes the potential for integrating AI-driven approaches into innovation in IBD treatments.

Molecular characterization and functional analysis of IL-18 in large yellow croaker (Larimichthys crocea)

Interleukin-18 (IL-18), a pro-inflammatory cytokine of the IL-1 family, is crucial for protecting the host against pathogen infection in mammals. In this study, a IL-18 homolog gene was cloned from large yellow croaker (Larimichthys crocea) (LcIL-18), which has an open reading frame (ORF) of 609 bp that encodes a polypeptide of 202 amino acids. The LcIL-18 C-terminus contains a typical IL-1 family signature and a caspase cleavage site. Phylogenetic analysis showed that LcIL-18 was most closely related to IL-18 of Miichthys miiuy. It was found that LcIL-18 was constitutively expressed in all 12 tissues tested of large yellow croakers, with the highest expression in gills. The expression of LcIL-18 in head kidney, spleen, skin, gills, and liver showed a differential pattern following infection with Pseudomonas plecoglossicida and Vibrio alginolyticus. P. plecoglossicida strongly induced LcIL-18 expression in these tissues. Conversely, in the early stage of infection, V. alginolyticus significantly inhibited LcIL-18 expression in head kidney, spleen, skin, and gills, but not in the liver. In vitro, LPS, Poly(I:C), P. plecoglossicida, and V. alginolyticus significantly upregulated the expression of the LcIL-18 in large yellow croaker head kidney (LYCK) cells. Furthermore, recombinant LcIL-18 (rLcIL-18) significantly increased cell viability and upregulated the expression of pro-inflammatory cytokines (LcIL-1β, LcIL-6, and LcTNF-α1) in LYCK cells. Our findings therefore indicated that LcIL-18 was involved in pro-inflammatory response induced by pathogenic bacteria.

Controlling pyroptosis through post-translational modifications of gasdermin D

Pyroptosis, a lytic and programmed cell death pathway, is mediated by gasdermins (GSDMs), with GSDMD playing an important role in innate immunity and pathology. Upon activation, GSDMD is cleaved to release the active N-terminal fragment that oligomerizes into membrane pores, which promote pyroptosis and cytokine secretion, leading to inflammation. Emerging evidence indicates that post-translational modification (PTM) is an important regulatory mechanism of GSDMD activity. This review explores how PTMs, aside from proteolytic cleavage, control GSDMD activity and link biological contexts to pyroptosis in innate immunity and inflammation, which could inform future studies and therapeutic solutions for treating inflammatory conditions.

Triggering Pyroptosis in Cancer

Pyroptosis is an inflammatory programmed cell death recently identified as a crucial cellular process in various diseases, including cancers. Unlike other forms of cell death, canonical pyroptosis involves the specific cleavage of gasdermin by caspase-1, resulting in cell membrane damage and the release of the pro-inflammatory cytokines IL-1β and IL-18. Initially observed in innate immune cells responding to external pathogens or internal death signals, pyroptotic cell death has now been observed in numerous cell types. Recent studies have extensively explored different ways to trigger pyroptotic cell death in solid tumors, presenting a promising avenue for cancer treatment. This review outlines the mechanisms of both canonical and noncanonical pyroptosis pertinent to cancer and primarily focuses on various biomolecules that can induce pyroptosis in malignancies. This strategy aims not only to eliminate cancer cells but also to promote an improved tumor immune microenvironment. Furthermore, emerging research indicates that targeting pyroptotic pathways may improve the effectiveness of existing cancer treatments, making them more potent against resistant tumor types, offering new hope for overcoming treatment resistance in aggressive malignancies.

Macrophage pyroptosis and its crucial role in ALI/ARDS

Acute lung injury(ALI)/acute respiratory distress syndrome(ARDS) is a severe clinical syndrome characterized by high morbidity and mortality, primarily due to lung injury. However, the pathogenesis of ALI/ARDS remains a complex issue. In recent years, the role of macrophage pyroptosis in lung injury has garnered extensive attention worldwide. This paper reviews the mechanism of macrophage pyroptosis, discusses its role in ALI/ARDS, and introduces several drugs and intervening measures that can regulate macrophage pyroptosis to influence the progression of ALI/ARDS. By doing so, we aim to enhance the understanding of the mechanism of macrophage pyroptosis in ALI/ARDS and provide novel insights for its treatment.

Matrine relieved DHAV-1-induced hepatocyte excessive interferon and pyroptosis by activating mitophagy

Duck hepatitis A virus type 1 (DHAV-1) is a significant pathogen affecting ducklings, capable of causing rapid mortality and adversely impacting the development of the duck industry. Matrine, the primary active ingredient in various Chinese herbal medicines, has demonstrated antiviral and anti-inflammatory properties. Nevertheless, the effects and mechanisms of action of matrine against DHAV-1 infection remain unclear. This research investigates the effects of matrine on DHAV-1 infection and elucidates the mechanisms involved. We found that matrine mitigated the excessive retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling response, pyroptosis, and mitochondrial damage induced by DHAV-1 in duckling livers and duck embryonic hepatocytes (DEHs). Additionally‌, by incorporating the autophagy inhibitor chloroquine, we observed that the effects of matrine on the regulation of excessive interferon (IFN) production, pyroptosis, mitochondrial damage, and oxidative stress were reversed. Overall, matrine inhibited excessive IFN production and pyroptosis by promoting mitophagy, suggesting that matrine may act as a possible therapeutic agent for addressing DHAV-1 infection and other viral hepatitis.