Search PubMedSearch

SEARCH · Search PubMed

Results for “Gasdermins”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

8 recordsLinked to original sources

Targeting Gasdermins for Therapeutic Interventions in Central Nervous System Injury.

Central nervous system (CNS) injuries are the leading cause of permanent disability and premature death in adults worldwide, with their incidence continuing to rise amid social development. These injuries not only severely impair the quality of life but also impose a heavy burden on the global public health system. Current clinical interventions, such as decompression and thrombolysis, can alleviate primary injury but fail to effectively reverse the secondary neuroinflammatory damage. Traditional anti-inflammatory therapies, which cannot block the upstream source of the inflammatory cascade, have led to repeated failures in global clinical translation research over the past decades. Gasdermins were first characterized in studies of systemic inflammatory diseases. These proteins form transmembrane pores to drive the release of proinflammatory factors and inflammatory cell death, serving as key mediators of host innate immunity. Recent studies have revealed that gasdermins play critical roles in regulating the initiation and amplification of neuroinflammation following CNS injury. To clarify the therapeutic potential of gasdermins as targets for injury repair, this review systematically summarizes the structure and function of gasdermins, as well as their cell-specific activation and regulatory mechanisms. We further elaborate on their pathological roles in these injuries and the corresponding therapeutic strategies, aiming to provide a theoretical reference for basic research and clinical translation in this field.

Humans

The phosphate exporter XPR1 promotes gasdermin D-independent mature IL-1β secretion.

Interleukin (IL)-1β is a leaderless inflammatory cytokine that is not secreted via the classical endoplasmic reticulum-Golgi pathway. Instead, m(ature) IL-1β secretion is classically associated with pyroptosis, a caspase-dependent inflammatory cell death mediated by gasdermin D (GSDMD) pore formation at the plasma membrane. However, human monocytes can secrete mIL-1β in the absence of cell death, and the contribution of GSDMD in this secretory pathway remains poorly defined. Here, we distinguished two pathways for mIL-1β secretion in living human monocytic cells : a rapid, GSDMD-dependent pathway and a slower, GSDMD-independent pathway. Using a genome-wide CRISPR-Cas9 screen, we identified XPR1 (Xenotropic and Polytropic retrovirus Receptor 1) as a regulator of the GSDMD-independent pathway. XPR1, the only phosphate exporter identified in metazoans, has not previously been implicated in cytokine secretion. Genetic invalidation of XPR1 in GSDMD-deficient monocytic cells markedly reduced IL-1β secretion. We further showed that this regulatory function requires XPR1 surface expression and phosphate export activity. These findings reveal an unexpected link between phosphate homeostasis and non-lytic mIL-1β secretion, opening new opportunities to modulate IL-1β-driven inflammatory diseases.

IL-1β secretion

MAPL regulates gasdermin-mediated release of mtDNA from lysosomes to drive pyroptotic cell death.

Mitochondrial control of cell death is of central importance to disease mechanisms from cancer to neurodegeneration. Mitochondrial anchored protein ligase (MAPL) is an outer mitochondrial membrane small ubiquitin-like modifier ligase that is a key determinant of cell survival, yet how MAPL controls the fate of this process remains unclear. Combining genome-wide functional genetic screening and cell biological approaches, we found that MAPL induces pyroptosis through an inflammatory pathway involving mitochondria and lysosomes. MAPL overexpression promotes mitochondrial DNA trafficking in mitochondrial-derived vesicles to lysosomes, which are permeabilized in a process requiring gasdermin pores. This triggers the release of mtDNA into the cytosol, activating the DNA sensor cGAS, required for cell death. Additionally, multiple Parkinson's disease-related genes, including VPS35 and LRRK2, also regulate MAPL-induced pyroptosis. Notably, depletion of MAPL, LRRK2 or VPS35 inhibited inflammatory cell death in primary macrophages, placing MAPL and the mitochondria-lysosome pathway at the nexus of immune signalling and cell death.

Lysosomes

Lytic coelomocyte death is tuned by cleavage but not phosphorylation of MLKL in echinoderms.

Lytic cell death including necroptosis and pyroptosis is induced by mixed lineage kinase domain-like protein (MLKL) phosphorylation and inflammatory caspase specific cleavage Gasdermins in higher mammals, respectively. In this study, we identified a novel MLKL homolog containing a tetrapeptide recognition motif (14-LVAD-17) of inflammatory caspase from Apostichopus japonicus,which was absent of Gasdermins member by genome screening. Functional analysis revealed that AjMLKL was involved in the regulation of Vibrio splendidus AJ01 infection induced lytic coelomocyte death in a cleavage-dependent manner, but not through RIPK3-dependent phosphorylation as mammals. Mechanistically, the activated form of cysteine-aspartic specific proteases-1 (AjCASP-1) bound to the tetrapeptide site of AjMLKL and cleaved it at Asp17. Cleaved AjMLKL18-491 displayed higher binding affinities towards phosphatidylinositol phosphate and cardiolipin compared to those of un-cleaved form. In addition, cleaved AjMLKL18-491 exerted stronger ability in disrupting the membrane integrity of liposome. More importantly, AjMLKL18-491 caused a large non-selective ionic coelomocyte pore and could directly kill the invasive AJ01. Moreover, activation of inflammatory AjCASP-1 was further found to be dependent on forming an inflammasome-like complex via CASc domain of AjCASP-1 and the N-terminal Ig domains of internalized AjNLRC4. All our results proved first evidence that lytic cell death was activated through MLKL cleavage, not MLKL phosphorylation in echinoderm, which offered insights into the functional, evolutionary mechanisms of lytic cell death in invertebrates.

Animals

Integrated bioinformatics analyses for GSDMB in carcinogenesis and progression of bladder cancer.

BACKGROUND: Emerging evidence suggests that pyroptosis influences the development of various diseases. Gasdermin B (GSDMB), an intracellular protein that executes pyroptosis, has recently attracted attention for its potential role in tumor biology. However, its specific function in bladder cancer (BLCA) remains unclear. Therefore, this study aimed to investigate the potential role of GSDMB in the carcinogenesis and prognosis of BLCA patients. METHODS: Mendelian randomization (MR) studies were conducted to examine relationships between the expression of GSDMB and BLCA with expression quantitative trait loci (eQTL) data. Then, GSDMB mRNA expression data and clinical characteristics of BLCA patients were retrieved from The Cancer Genome Atlas (TCGA) database. Cox regression was used to explore the relationship between GSDMB mRNA expression and patients' survival. Additionally, the correlation between GSDMB and the immune microenvironment, tumor mutational burden (TMB), tumor microenvironment (TME), and drug sensitivity in BLCA was examined. RESULTS: According to MR analysis based on eQTLs, GSDMB mRNA expression has positive causal effects on bladder carcinogenesis and the need for bladder surgery (P<0.05). The analyses of TCGA demonstrated an increased expression of GSDMB in BLCA tissues, correlating with improved patient survival. Additionally, elevated GSDMB mRNA expression was identified as an independent protective prognostic factor for BLCA, and it was associated with immune cell infiltration, TMB, TME score, and drug sensitivity. CONCLUSIONS: Elevated mRNA expression of GSDMB has a causal link to a higher risk of BLCA and the likelihood of bladder surgery, but also indicates a better prognosis. Thus, GSDMB exhibits dual effects and might serve as a potential biomarker for predicting onset and progression of BLCA. Nevertheless, further investigation of pathogenesis and mechanisms underlying GSDMB is warranted.

Bladder cancer (BLCA)

Functional chimeric mRNAs encode proteins in mammalian immunity.

Individual mammalian mRNAs and proteins are typically believed to originate from single genomic loci, with isoform diversity arising through cis-splicing of pre-mRNA. Whether mRNA from distant genes can undergo trans-splicing to generate functionally relevant chimeric transcripts has remained unclear. Here we develop a pipeline combining long-read direct RNA sequencing with non-targeted and targeted validation to identify chimeric transcripts in macrophages. Chromatin conformation capture studies reveal that inflammation induces interchromosomal DNA interactions, positioning parent genes proximally to facilitate the formation of chimeric mRNA. Notably, we identify a protein-coding chimeric mRNA representing a fusion between the pore-forming protein gasdermin D (GSDMD)1,2 and a C-terminal domain translated out of frame from Tmem106a (Gsdmd-Tmem106a) in mice. We show that inflammasome priming upregulates Gsdmd-Tmem106a, with the protein localizing to the plasma membrane. After activation of the inflammasome, GSDMD-TMEM106A directly interacts with canonical GSDMD N termini to accelerate and enhance pore formation and IL-1&#x3b2; release. Finally, we show that GSDMD-TMEM106A balances host defence and immunopathology in vivo: its loss protects against lethal sepsis but compromises antibacterial defence, whereas overexpression enhances host protection while increasing sepsis lethality. We establish that protein-coding chimeric mRNAs formed by regulated transcript fusion events are operative during inflammation and immunity.

Journal Article

NLRP3 and AIM2 inflammasomes exacerbate the pathogenic Th17 cell response to eggs of the helminth Schistosoma mansoni.

Infection with the helminth Schistosoma mansoni can cause exacerbated morbidity and mortality via a pathogenic host CD4 T cell-mediated immune response directed against parasite egg antigens, with T helper (Th) 17 cells playing a major role in the development of severe granulomatous hepatic immunopathology. The role of inflammasomes in intensifying disease has been reported; however, neither the types of caspases and inflammasomes involved, nor their impact on the Th17 response are known. Here we show that enhanced egg-induced IL-1&#x3b2; secretion and pyroptotic cell death required both caspase-1 and caspase-8 as well as NLRP3 and AIM2 inflammasome activation. Schistosome genomic DNA activated AIM2, whereas reactive oxygen species, potassium efflux and cathepsin B, were the major activators of NLRP3. NLRP3 and AIM2 deficiency led to a significant reduction in pathogenic Th17 responses, suggesting their crucial and non-redundant role in promoting inflammation. Additionally, we show that NLRP3- and AIM2-induced IL-1&#x3b2; suppressed IL-4 and protective Type I IFN (IFN-I) production, which further enhanced inflammation. IFN-I signaling also curbed inflammasome- mediated IL-1&#x3b2; production suggesting that these two antagonistic pathways shape the severity of disease. Lastly, Gasdermin D (Gsdmd) deficiency resulted in a marked decrease in egg-induced granulomatous inflammation. Our findings establish NLRP3/AIM2-Gsdmd axis as a central inducer of pathogenic Th17 responses which is counteracted by IFN-I pathway in schistosomiasis.

Animals

Upper airway microbiome interacts with GSDMB and ORMDL3 asthma risk SNPs to influence early-life wheeze risk.

BACKGROUND: Single-nucleotide polymorphisms (SNPs) in the chromosome 17q12-q21 region and, independently, early-life nasal microbiota dominated by Moraxella, Streptococcus, or Haemophilus (MSH) increase risk of chronic wheeze and asthma development. OBJECTIVE: We sought to determine whether 17q12-q21 risk SNPs and nasal microbiota interact to modulate childhood wheeze risk. METHODS: Nasal wash samples from 12-month-old infants in 2 birth cohorts, COAST (Childhood Origins of Asthma; n = 180) and URECA (Urban Environment and Childhood Asthma; n = 139), underwent 16S ribosomal RNA variable region 4 sequencing. Nasal microbiota dominated by MSH or Corynebacterium, Dolosigranulum, Staphylococcus, or Bacillus (CDSB) were assessed. Paired blood was genotyped for 9 17q12-q21 risk SNPs. Logistic regression tested interactions between 17q12-q21 SNPs and MSH or CDSB on wheeze risk in the first 3 years of life. A549 lung epithelial cells, CRISPR-edited to encode the rs7216389 risk genotype (rs7216389TT) were compared to the heterozygous (rs7216389CT) line using bulk RNA sequencing. RESULTS: SNPs, particularly those in the ORMDL3 (rs8076131; odds ratio [OR]: 1.72; 95% CI: 1.09-2.71; Pint = .031) and GSDMB (rs2305480; OR: 1.72; 95% CI: 1.09-2.71; Pint = 0.042; and rs7216389; OR: 1.73; 95% CI: 1.09-2.70; Pint = .047) genes, interact with MSH microbiota to increase early-life wheeze risk (false discovery rate Pint = .016 for all), while interactions with CDSB reduce risk. A549 airway epithelial cells homozygous for rs7216389TT exhibited decreased expression of genes involved in antimicrobial responses and neutrophil recruitment and evidence increased microbial adherence compared with the heterozygous cell line. CONCLUSION: Airway microbiota interact with SNPs at the 17q12-q21 locus in genes involved in sphingolipid metabolism and intracellular antimicrobial responses, to modulate wheeze risk.

Humans