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The Novel Hypomethylating Agent NTX-301 Reprograms Epigenetic and Hippo Signaling Pathways and Exhibits Preclinical Activity in Venetoclax-Resistant and TP53-Mutant AML.

PURPOSE: Hypomethylating agent (HMA) and the BCL-2 inhibitor venetoclax (VEN) combinations have evolved into first-line therapies for patients with acute myeloid leukemia (AML), yielding high response rates. However, most patients ultimately relapse, particularly those with TP53 mutations. We investigated mechanisms of action and therapeutic efficacy of NTX-301, a next-generation HMA. EXPERIMENTAL DESIGN: Methods used include flow cytometry-based cell viability assays, Western blotting, reverse-phase protein arrays, RNA sequencing, Cytometry by Time-Of-Flight single-cell mass cytometry, and methylation profiling in various therapy-resistant AML models. RESULTS: We demonstrate that NTX-301 exhibits superior efficacy compared with 5-azacytidine (5-AZA) in 5-AZA- or VEN-resistant AML. It synergizes with VEN in VEN- or VEN/HMA-resistant and TP53-mutant AML blasts and stem/progenitor cells (combination index <1). NTX-301 inhibits DNA methyltransferase 1 (DNMT1) and increases p73 and caspase 8 (CASP8)/activated CASP8 levels in TP53 wild-type and TP53-mutant AML and activates p53 signaling. It extends survival (&#x2265;45%) in both xenograft and patient-derived xenograft models. Methylation profiling revealed that NTX-301 is a more targeted HMA compared with 5-AZA, enabling suppression of functionally enriched genes/pathways. Pathway analysis of 954 commonly hypomethylated genes showed profoundly greater enrichment of Hippo signaling in NTX-301-treated compared with 5-AZA-treated cells and enrichment of insulin signaling, VEGF pathway, and cell cycle selectively in NTX-301- but not in 5-AZA-treated cells. NTX-301-mediated Hippo signaling was validated at protein levels. CONCLUSIONS: Data suggest that NTX-301 exerts potent antileukemic activities superior to 5-AZA and synergizes with VEN in VEN-resistant and TP53-mutant AML, in part by suppressing DNMT1, inducing DNA damage responses and apoptosis through p53 signaling, and demethylating LATS1/2, thereby activating Hippo signaling.

Humans

Evolutionary and Functional Analysis of Caspase-8 and ASC Interactions to Drive Lytic Cell Death, PANoptosis.

Caspases are evolutionarily conserved proteins essential for driving cell death in development and host defense. Caspase-8, a key member of the caspase family, is implicated in nonlytic apoptosis, as well as lytic forms of cell death. Recently, caspase-8 has been identified as an integral component of PANoptosomes, multiprotein complexes formed in response to innate immune sensor activation. Several innate immune sensors can nucleate caspase-8-containing PANoptosome complexes to drive inflammatory lytic cell death, PANoptosis. However, how the evolutionarily conserved and diverse functions of caspase-8 drive PANoptosis remains unclear. To address this, we performed evolutionary, sequence, structural, and functional analyses to decode caspase-8's complex-forming abilities and its interaction with the PANoptosome adaptor ASC. Our study distinguished distinct subgroups within the death domain superfamily based on their evolutionary and functional relationships, identified homotypic traits among subfamily members, and captured key events in caspase evolution. We also identified critical residues defining the heterotypic interaction between caspase-8's death effector domain and ASC's pyrin domain, validated through cross-species analyses, dynamic simulations, and in vitro experiments. Overall, our study elucidated recent evolutionary adaptations of caspase-8 that allowed it to interact with ASC, improving our understanding of critical molecular associations in PANoptosome complex formation and the underlying PANoptotic responses in host defense and inflammation. These findings have implications for understanding mammalian immune responses and developing new therapeutic strategies for inflammatory diseases.

Caspase 8

Establishing a genetic mutation panel for predicting malignant transformation of oral leukoplakia: A prospective cohort study.

OBJECTIVE: To investigate somatic mutations in the whole genes of tissue samples from patients with oral leukoplakia (OLK), as the most typical precursor of oral cancer; and identify the specific genes as a mutational panel for predicting OLK malignant transformation. METHODS: A total of 123 consecutive OLK patients with long-term follow-up (median, 73&#xa0;months) were prospectively enrolled, and divided into training set (n&#xa0;=&#xa0;92) and independent test set (n&#xa0;=&#xa0;31) based on chronological order of enrollment. Genomic DNA was isolated from the fresh-frozen biopsy tissues and somatic mutations in all genes were measured by whole-exome sequencing. RESULTS: We constructed a 3-gene (TP53, CASP8, and CYP2B6) mutational panel for risk stratification (any mutation vs. no mutation) of OLK malignant transformation. Kaplan-Meier analysis showed that the prognostic power of the 3-gene panel (log-rank P&#xa0;<&#xa0;0.0001) for risk stratification in malignant progression was better than that of pathological grade in the training and test set, respectively. Multivariate Cox regression analysis revealed that this panel was an independent variable significantly associated with progression in the training (hazard ratio [HR]&#xa0;=&#xa0;8.05; P&#xa0;<&#xa0;0.001) and test set (HR&#xa0;=&#xa0;11.26; P&#xa0;=&#xa0;0.0421), respectively. The area under the curve (AUC) with 95&#xa0;% confidence interval was 0.770 (0.648-0.892) and 0.877 (0.705-1.000) in the training and test set, respectively, for predicting malignant transformation in OLK patients. CONCLUSIONS: We established a 3-gene (TP53, CASP8, and CYP2B6) mutational panel as risk stratification model could effectively predict OLK malignant transformation, outperforming pathological grading-based assessment. Such genetic markers may provide a foundation for developing personalized management strategies.

Humans

Multi-Omics Platforms Reveal Synergistic Intestinal Toxicity in Tilapia from Acute Co-Exposure to Polystyrene Microplastics, Sulfamethoxazole, and BDE153.

Polystyrene microplastic (MP) and its co-existing contaminants may exert different toxic effects on its surrounding aquatic organisms. In order to detect the intestinal harmful responses, tilapia were subjected to exposure with 75 nm of MPs, 100 ng&#xb7;L-1 of sulfamethoxazole (SMZ), 5 ng&#xb7;L-1 of BDE153, and combinations thereof over periods of 2, 4, and 8 days. Enzymatic assays, transcriptomics, proteomics, and metabolomics were employed to evaluate intestinal histopathological effects. Results showed that significant reductions were observed in ATP, ROS, SOD, EROD, lipid metabolism-related enzymes, pro-inflammatory cytokines (TNF&#x3b1; and IL-1&#x3b2;), and apoptosis marker caspase 3 across all groups at day 8. Histological evaluation revealed diminished goblet cell density, with distinct vacuole formation in the BDE153+MPs group. KEGG pathway analysis highlighted disruptions in endocytosis, MAPK signaling, phagosome formation, and actin cytoskeleton regulation. Proteomic findings indicated notable enrichment in endocytosis (decreased sorting nexin-2; increased Si:dkey-13a21.4), MAPK/PPAR signaling, protein processing in the endoplasmic reticulum (Sec61 subunit gamma), and cytoskeletal modulation (reduced fibronectin; elevated activation peptide fragment 1), with or without SMZ and BDE153. Metabolomic profiling showed significant alterations in ABC transporters, aminoacyl-tRNA biosynthesis, protein digestion and absorption, and linoleic acid metabolism. In summary, these findings suggest that BDE153 and MPs synergistically exacerbate intestinal damage and gene/protein expression over time, while SMZ appears to exert an antagonistic, mitigating effect.

Animals

Eucalyptol mitigates isoproterenol-induced myocardial injury in rats via activation of p38 MAPK/JNK signaling, suppression of ER stress, and modulation of apoptotic pathway.

BACKGROUND: Myocardial injury (MI), a subset of cardiovascular diseases, remains a leading cause of deaths globally, driven by pathological inflammation, oxidative stress, and apoptosis. Despite advances in interventional cardiology, high relapse rates and therapeutic limitations underscore the urgent need for novel pharmacological agents. Phytochemicals, with their multi-target approach and favorable safety profiles, offer promising alternatives for mitigating ischemic injury. METHODS: The cardioprotective effects of 1,8-cineole, a monoterpene derived from Eucalyptus species, was investigated in a rat model of isoproterenol-induced myocardial injury. Serum levels of cardiac enzymes (creatine kinase (CK), lactate dehydrogenase (LDH)) and pro-inflammatory cytokines (TNF-&#x3b1;, IL-6, IL-1&#x3b2;) were quantified. Preliminary histopathological analysis was performed to assess the extent of myocardial damage. Key molecular mechanisms were evaluated via western blotting and immunohistochemistry, examining pathways related to inflammation (NF-&#x3ba;B), apoptosis (Bcl-2/Bax, caspase-3), endoplasmic reticulum (ER) stress (GRP78, CHOP, PERK-eIF2&#x3b1;), and antioxidant defense (GSH, SOD, CAT). RESULTS: Our results demonstrate that 1,8-cineole significantly reduced the levels of serum cardiac enzymes (CK-MB, LDH), and histopathological damage. Mechanistically, 1,8-cineole also suppressed pro-inflammatory cytokine release (TNF-&#x3b1;, IL-6, and IL-1&#x3b2;) via inhibition of the NF-&#x3ba;B pathway. Furthermore, it attenuated cardiomyocyte apoptosis by modulating Bcl-2/Bax expression and inhibiting caspase-3 activation. Additionally, 1,8-cineole alleviated ER stress by downregulating GRP78, CHOP, and PERK-eIF2&#x3b1; signaling. Importantly, we identified enhanced Nrf2 nuclear translocation and subsequent upregulation of antioxidant enzymes (GSH, SOD, CAT) as key contributors to its cytoprotective effects. CONCLUSIONS: 1,8-Cineole exhibits potent cardio-protection in experimental myocardial injury by targetinginflammation, apoptosis, ER stress, and oxidative stress through modulation of p38 MAPK/JNK, suppression of inflammatory markers (TNF-&#x3b1;, IL-6, IL-1&#x3b2;) and apoptotic markers (Bax, p53). Its natural origin, bioavailability, and multi-mechanistic effectiveness make it a promising candidate for translational development as an adjunct therapy for myocardial injury.

Animals

Targeted Dynamic Phospho-Proteogenomic Analysis of Gastric Cancer Cells Suggests Host Immunity Provides Survival Benefit.

Despite of massive emergence of molecular targeting drugs, the mainstay of advanced gastric cancer (GC) therapy is DNA-damaging drugs. Using a reverse-phase protein array-based proteogenomic analysis of a panel of 8&#xa0;GC&#xa0;cell lines, we identified genetic alterations and signaling pathways, potentially associated with resistance to DNA-damaging drugs, including 5-fluorouracil (5FU), cisplatin, and etoposide. Resistance to cisplatin and etoposide, but not 5FU, was negatively associated with global copy number loss, vimentin expression, and caspase activity, which are considered hallmarks of previously established EMT subtype. The segregation of 19,392 protein expression time courses by sensitive and resistant cell lines for the drugs tested revealed that 5FU-resistant cell lines had lower changes in global protein dynamics, suggesting their robust protein level regulation, than their sensitive counterparts, whereas the cell lines that are resistant to other drugs showed increased protein dynamics in response to each drug. Despite faint global protein dynamics, 5FU-resistant cell lines showed increased signal transducer and activator of transcription 1 phosphorylation and PD-L1 expression in response to 5FU. In publicly available cohort data, expression of signal transducer and activator of transcription 1 and NF&#x3ba;B target genes induced by proinflammatory cytokines was associated with prolonged survival in GC. In our validation cohort, total lymphocyte count, rather than PD-L1 positivity, predicted a better relapse-free survival rate in GC patients with 5FU-based adjuvant chemotherapy than those with surgery alone. Moreover, total lymphocyte count+ patients who had no survival benefit from adjuvant chemotherapy were discriminated by expression of I&#x3ba;B&#x3b1;, a potent negative regulator of NF&#x3ba;B. Collectively, our results suggest that 5FU resistance observed in cell lines may be overcome by host immunity or by combination therapy with immune checkpoint blockade.

Stomach Neoplasms

Streptococcus pyogenes EVs induce the alternative inflammasome via caspase-4/-5 in human monocytes.

The sensing of Gram-negative Extracellular Vesicles (EVs) by the innate immune system has been extensively studied in the past decade. In contrast, recognition of Gram-positive EVs by innate immune cells remains poorly understood. Comparative genome-wide transcriptional analysis in human monocytes uncovered that S. pyogenes EVs induce proinflammatory signatures that are markedly distinct from those of their parental cells. Among the 209 genes exclusively upregulated by EVs, caspase-5 prompted us to study inflammasome signaling pathways in depth. We show that lipoteichoic acid (LTA), a structural component of Gram-positive bacterial membranes present on EVs from S. pyogenes and other Gram-positive species, is sensed by TLR2 which triggers the alternative inflammasome composed of NLRP3 and the inflammatory caspases-4/-5 to mount an IL-1&#x3b2; response without inducing cell death. For S. pyogenes, we identify TLR8 as a sensor to mediate caspase-4/-5-dependent IL-1&#x3b2; secretion. Notably, inflammasome activation by intact bacteria is independent of the global virulence regulator CovS in monocytes. Overall, our study highlights a new role for TLR2 and caspase-4/-5 in the recognition of Gram-positive EVs in human monocytes.

Humans

PDE4DIP-Derived MMG8 Supports Proliferation, Migration, and Tumor Growth in Hepatocellular Carcinoma Models.

BACKGROUND: PDE4DIP encodes a scaffold protein that has been implicated in compartmentalized signaling and cytoskeletal organization, but the role of its myomegalin variant 8 (MMG8) isoform in hepatocellular carcinoma (HCC) remains unclear. To address this gap, we examined PDE4DIP expression in public HCC datasets and investigated the functional role of MMG8 in HCC models. METHODS: PDE4DIP expression was analyzed in The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) cohort and two Gene Expression Omnibus (GEO) cohorts (GSE14520, GSE36376). MMG8 function was assessed in Huh7 cells using siRNA-mediated knockdown and in Hepa1-6 cells using lentiviral Clustered Regularly Interspaced Short Palindromic Repeats - CRISPR-associated protein 9 (CRISPR-Cas9)-mediated knockout. Cell proliferation in MMG8-KD Huh7 cells and MMG8-KO Hepa1-6 cells was assessed using Cell Counting Kit-8 (CCK-8) assays, while Huh7 cell migration was evaluated using Transwell assays. Tumor growth was assessed using a murine subcutaneous tumor model. Immunohistochemical staining for Ki67 and cleaved caspase-3 was employed to assess tumor cell proliferation and apoptosis-associated changes, respectively. Gene set enrichment analysis was performed in TCGA-LIHC tumors stratified based on PDE4DIP expression. RESULTS: PDE4DIP expression differed between tumor and non-tumor tissues across HCC cohorts, although the directionality of this difference was not uniform. MMG8 knockdown in Huh7 cells reduced proliferation and migratory activity. A single-cell-derived MMG8-KO Hepa1-6 clone exhibited reduced proliferation in vitro and formed smaller tumors in vivo, with lower Ki67 positivity but no significant difference in cleaved caspase-3 positivity between groups. In tumors from the TCGA-LIHC cohort, PDE4DIP expression was associated with distinct transcriptional programs. Specifically, PDE4DIP-high tumors presented with positive normalized enrichment score (NES) values for several metabolic pathways, whereas adhesion/extracellular matrix (ECM), cell cycle/proliferation, and translation/ribosome-related pathways exhibited negative NES values. CONCLUSIONS: These findings support a functional contribution of MMG8 to proliferative, migratory, and tumor-growth phenotypes in the tested HCC models. Bulk gene-level PDE4DIP expression in human tumors was associated with context-dependent transcriptional states and should not be interpreted as a direct surrogate for MMG8 function.

Liver Neoplasms