bims-cediti Biomed News
on Cell death in innate immunity, inflammation, and tissue repair
Issue of 2025–06–08
eighteen papers selected by
Kateryna Shkarina, Universität Bonn



  1. bioRxiv. 2025 May 19. pii: 2025.05.19.654850. [Epub ahead of print]
      As intracellular parasites, viruses must devise sophisticated mechanisms to produce and assemble viral components while suppressing activation of innate immune effectors. Here, we report that coordination of HIV-1 assembly by the viral polyprotein Gag suppresses inappropriately-timed protease (PR) activity to evade the PR activity sensor, CARD8. Employing mutants of Gag, we show that disruption of domains controlling viral assembly site (MA) or virus particle release (NC and p6) lead to premature activation of PR and the CARD8 inflammasome, resulting in IL-1β secretion and pyroptotic cell death. Further, we demonstrate that previously-observed host-adaptive mutations in HIV-1 MA (M30K) and p6 (PTAP duplication) associated with greater fitness in humans differentially modulate the process of viral assembly and budding to evade CARD8-mediated cell death. Altogether, this work reveals adaptation to human CARD8 by HIV-1 Gag upon zoonotic transmission from chimpanzees and suggests that assembly-regulated CARD8 activation influences the trajectory of HIV-1 evolution and fitness in humans.
    DOI:  https://doi.org/10.1101/2025.05.19.654850
  2. Biochem Biophys Res Commun. 2025 May 28. pii: S0006-291X(25)00824-1. [Epub ahead of print]775 152110
      Human cytomegalovirus (HCMV) infection of monocytes results in inflammatory response by triggering the activation of inflammasomes and subsequent release of inflammatory cytokines including IL-1β and IL-18 and pyroptosis. However, the mechanisms by which HCMV induces inflammatory response remain unclear. Here, we identified that the HCMV protein US18 promotes NLRP3 inflammasome activation, IL-1β release and pyroptosis. US18 associates with the NLRP3 inflammasome components NEK7, NLRP3 and pro-IL-1β, and promotes the oligomerization and speck formation of NLRP3. Knockdown of US18 inhibits HCMV-induced activation of the NLRP3 inflammasome, IL-1β release and pyroptosis. Our findings suggest that HCMV US18 positively regulates activation of the NLRP3 inflammasome and inflammatory response upon HCMV infection.
    Keywords:  Human cytomegalovirus; NLRP3 inflammasome; Pyroptosis; US18
    DOI:  https://doi.org/10.1016/j.bbrc.2025.152110
  3. Front Pharmacol. 2025 ;16 1586364
      Pyroptosis is an inflammatory form of cell death involving caspase-1 or caspase-4/5/11, initiated by inflammasomes or cytoplasmic endotoxins as part of the immune defense. It is specifically characterized by Gasdermin-mediated pore formation leading to cell lysis, pyroptosis also entails the release of pro-inflammatory cytokines. As a natural mechanism of the immune system, it activates in response to harmful stimuli to eliminate threats and facilitate tissue repair. However, excessive pyroptosis can lead to detrimental outcomes, such as infectious shock, multiple organ dysfunction syndrome (MODS), and increased susceptibility to secondary infections. Sepsis, an unchecked immune response to infection, remains a leading cause of MODS and death among critically ill patients. The pathogenesis of sepsis is complex and multifaceted, involving innate inflammation that kills infected cells and releases pro-inflammatory cytokines. Recent research has increasingly explored the link between pyroptosis and sepsis, focusing on its mechanisms, roles, and potential therapeutic targets. There has been significant advancement in understanding pyroptosis, highlighting its vital role in the development of sepsis. This review delves into the molecular and pathophysiological roles of inflammasomes and pyroptosis in sepsis, with a particular emphasis on the impact on specific organs such as the heart, lungs, liver, kidney and brain, aiming to identify new diagnostic markers and therapeutic targets for sepsis management.
    Keywords:  NLRP3 inflammasome; caspase-1; organ dysfunction; pyroptosis; sepsis
    DOI:  https://doi.org/10.3389/fphar.2025.1586364
  4. Cell Rep. 2025 Jun 04. pii: S2211-1247(25)00556-X. [Epub ahead of print]44(6): 115785
      Glycolysis is a critical player in the inflammatory response. Phosphoglycerate kinase 1 (PGK1) is an essential enzyme in the glycolysis pathway. However, little is known about its role in inflammatory response. In this study, we report PGK1 as a kinase that directly regulates NLRP3 inflammasome activation in response to lipopolysaccharide (LPS) stimulation via non-glycolytic function. We identified a novel phosphorylation modification of PGK1 at S271, mediated by protein kinase CK2. Importantly, phosphorylation at S271 serves as a molecular switch that activates PGK1's kinase function, activating it to phosphorylate NLRP3. This PGK1-mediated phosphorylation at S448/S449 of NLRP3 subsequently recruits USP14 to facilitate NLRP3 deubiquitination, thereby promoting NLRP3 inflammasome activation. Using PGK1S271A/S271A transgenic mouse model, we further demonstrated that blocking S271 phosphorylation conferred significant protection against LPS-induced endotoxemia and alum-induced peritonitis. Our findings reveal a novel regulatory role of PGK1 in inflammation and provide potential therapeutic strategies for NLRP3-driven diseases.
    Keywords:  CK2; CP: Immunology; CP: Metabolism; NLRP3; PGK1; USP14; inflammasome; phosphorylation
    DOI:  https://doi.org/10.1016/j.celrep.2025.115785
  5. Aging Dis. 2025 Jun 02.
      Neutrophils are among the earliest and most abundant immune cells infiltrating the brain following ischemic stroke, aggravating neuroinflammation through the formation of neutrophil extracellular traps (NETs). Pyroptosis, an inflammasome-mediated form of programmed cell death, occurs in post-stroke brain tissue and amplifies inflammation by releasing proinflammatory mediators, propagating the inflammatory cascade. However, the mechanistic link between NETs and pyroptosis remains unclear. This study demonstrated significantly elevated NET levels in arterial blood at the infarct site compared with venous or femoral arterial blood in stroke patients. A positive correlation was observed between the 24-h change in NIHSS score (NIHSSbaseline - NIHSS24h) and the difference in arterial citrullinated histone 3 (CitH3)-DNA (NETs) levels between the infarct site and femoral artery (NETsinfarct site - NETsfemoral artery). In a murine stroke model, NETs were detected in the brain parenchyma. Pharmacological inhibition of NET formation with GSK484, a selective protein-arginine deiminase type 4 antagonist, suppressed NET production, reduced absent in melanoma 2 (AIM2) inflammasome expression, and improved neurological outcomes in mice following stroke. AIM2 knockdown in brain tissue achieved similar neuroprotective effects. In both BV2 cells and stroke-induced mice, NETs triggered AIM2-dependent pyroptosis. These findings suggest that neutrophils in peripheral blood infiltrate the brain parenchyma to generate NETs, activating the AIM2 inflammasome in microglia and exacerbating stroke-induced brain injury through pyroptosis. Targeting NET formation or AIM2 inflammasome activation represents a potential therapeutic strategy for attenuating post-stroke neuroinflammation and secondary neuronal damage.
    DOI:  https://doi.org/10.14336/AD.2024.1733
  6. Nat Commun. 2025 Jun 02. 16(1): 5126
      Focal gene amplification serves as an oncogenic driver during tumorigenesis and is a hallmark of many forms of cancer. Oncogene amplifications promote genomic instability, which is integral to cancer cell survival and evolution. However, focal gene amplification potentially affords an opportunity for therapeutic exploitation. As a proof-of-concept, we leverage CRISPR-Cas9 nickase to selectively promote cancer cell death in MYCN-amplified neuroblastoma in a gene amplification-dependent manner. Our analysis demonstrates that CRISPR-Cas9 nickase can generate a lethal number of highly toxic, replication-dependent double-strand breaks in cells harboring amplified loci. Furthermore, we demonstrate that Cas9 nickase-mediated toxicity can be modulated in combination with small molecule inhibitors targeting key regulators of the DNA-damage response or cell death pathways. Importantly, our findings in MYCN-amplified neuroblastoma translate to other cancer types with distinct oncogene amplifications.
    DOI:  https://doi.org/10.1038/s41467-025-60160-2
  7. Redox Biol. 2025 May 23. pii: S2213-2317(25)00209-5. [Epub ahead of print]84 103696
      Extracellular traps (NETs) released by neutrophils during inflammation play a role in clearing infection but also contribute to disease pathology. NETs consist of a DNA backbone containing histones, anti-microbial granule proteins, such as myeloperoxidase (MPO), and other proteins. MPO remains enzymatically active and generates hypochlorous acid (HOCl) to kill pathogens. However, HOCl also readily reacts with proteins, but whether histones and other NET proteins are modified by this oxidant is unknown. This is significant as post-translational modification of histones alters their intracellular and extracellular reactivity. In this study, we used a proteomic approach to characterise the protein composition of NETs and identify HOCl-induced oxidative modifications on histones and other proteins. NETs were collected from primary neutrophils and the PLB-985 cell line and stimulated with phorbol myristate acetate (PMA) or nigericin, a bacterial peptide derived from Streptomyces hygroscopicus. There was evidence for Lys nitrile and aminoadipic semialdehyde formation, Tyr and Trp chlorination, and Met oxidation on histones and other proteins, including quinone oxidoreductase. Chlorination of Tyr-88 on histone H4 was particularly abundant and occurred to a greater extent in NETs from neutrophils exposed to PMA compared to nigericin, consistent with nigericin triggering NET release via a non-oxidative pathway. Chlorination of histone H4 Tyr-88 was also observed in the nuclear and cytoplasmic cell extracts of stimulated cells and could be decreased on treatment of the neutrophils with the MPO inhibitor AZD5904. These findings provide the first evidence that HOCl modifies proteins within NETs, particularly histone H4, which may be relevant in disease.
    Keywords:  3-Chlorotyrosine; Hypochlorous acid; Inflammation; Neutrophil; Post-translational modification
    DOI:  https://doi.org/10.1016/j.redox.2025.103696
  8. bioRxiv. 2025 May 19. pii: 2025.05.16.654477. [Epub ahead of print]
      Lysosomal damage is an endogenous danger signal to the cell, but its significance for innate immunity and how specific signaling pathways are engaged by this stressor remain unclear. Here, we uncover an immune-inducible pathway that connects lysosomal damage to mitochondrial DNA (mtDNA) efflux and type I IFN production. Lysosomal damage elicits mitochondrial outer membrane permeabilization (MOMP) via BAK/BAX macropores; however, the inner mitochondrial membrane (IMM) prevents wholesale mtDNA release in resting cells. Priming with type II IFN (IFN-γ) induced the antibacterial effector apolipoprotein L-3 (APOL3), which upon transient lysosomal damage, targets mitochondria undergoing MOMP and selectively permeabilizes the IMM to enhance mtDNA release and activate cGAS/STING signaling. Biochemical and cellular reconstitution revealed that analogous to its bactericidal detergent-like mechanism, APOL3 solubilizes cardiolipin to permeabilize the IMM. Our findings illustrate how cells use an antibacterial protein to expedite the breakdown of endosymbiosis and facilitate a heightened response to injury and infection.
    DOI:  https://doi.org/10.1101/2025.05.16.654477
  9. Infect Immun. 2025 Jun 05. e0056524
      The proinflammatory cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) is required for host defense against a wide range of pathogens. During infection with the intracellular bacterial pathogen Legionella pneumophila, we previously found that GM-CSF enhances inflammatory cytokine production in murine monocytes and is required for in vivo control of Legionella. It is unclear whether GM-CSF similarly augments cytokine production in human monocytes during bacterial infection. Here, we find that GM-CSF enhances inflammatory cytokine expression in Legionella-infected human monocytes by engaging multiple signaling pathways. Legionella- and Toll-like receptor-dependent NF-[Formula: see text]B signaling is a prerequisite signal for GM-CSF to promote cytokine expression. Then, GM-CSF-driven Janus kinase 2/signal transducer and activator of transcription 5 signaling is required to augment cytokine expression in Legionella-infected human monocytes. We also found a role for phosphatidylinositol-3-kinase/Akt/mTORC1 signaling in GM-CSF-dependent upregulation of cytokine expression. Finally, glycolysis and amino acid metabolism are also critical for GM-CSF to boost cytokine gene expression. Our findings show that GM-CSF-mediated enhancement of cytokine expression in infected human monocytes is regulated by multiple signaling pathways, thereby allowing the host to fine-tune antibacterial immunity.
    Keywords:  Akt; GM-CSF; Legionella pneumophila; NF-kB; PI-3K; TLR; amino acid metabolism; glycolysis; human monocytes; mTORC1
    DOI:  https://doi.org/10.1128/iai.00565-24
  10. Sci Rep. 2025 Jun 03. 15(1): 19413
      Orthodontic tooth movement (OTM) has been described as a bone remodeling process mediated by the expression of various inflammatory cytokines, including tumor necrosis factor-α (TNF-α). Necroptosis is a form of regulated cell death that is mainly induced by TNF-α, leading to the release of damage-associated molecular patterns (DAMPs) that cause inflammation. However, the role of osteocyte necroptosis in regulating osteoclastogenesis during OTM remains unclear. Here, we investigated the effects of osteocyte necroptosis on osteoclastogenesis in a mouse model of OTM. In wild-type mice, osteocyte death was remarkably increased on day 6 after OTM. Transmission electron microscopy identified apoptotic osteocytes, necrotic osteocytes, and empty lacunae based on morphological characteristics. TNF receptor type 1- and 2-deficient (TNFRsKO) mice showed a reduction in osteocyte death on day 6 after OTM. Immunofluorescence staining detected necroptosis markers in osteocytes on the compression side in wild-type OTM mice, whereas such osteocytes were almost undetectable in TNFRsKO OTM mice. Furthermore, the conditioned medium from primary osteocytes undergoing necroptosis significantly enhanced osteoclastogenesis. These findings suggest that TNF-α-induced osteocyte necroptosis enhances osteoclastogenesis and alveolar bone resorption on the compression side during OTM, involving the release of inflammatory factors including DAMPs.
    Keywords:  Damage-associated molecular patterns (DAMPs); Necroptosis; Orthodontic tooth movement; Osteoclasts; Osteocytes; TNF-α
    DOI:  https://doi.org/10.1038/s41598-025-04697-8
  11. Proc Natl Acad Sci U S A. 2025 Jun 10. 122(23): e2504819122
      The death-inducing signaling complex (DISC), comprising Fas, Fas-associated death domain (FADD), and caspase-8, initiates extrinsic apoptosis. Using cryogenic electron microscopy (cryo-EM), we show that Fas and FADD death domains (DDs) form an asymmetric 7:5 oligomer, which promotes FADD death effector domain (DED) filament formation. Structural analysis reveals that FADD DED filaments closely resemble caspase-8 tandem DED filaments, suggesting that FADD DED serves as a nucleation scaffold for caspase-8 assembly. These findings provide a mechanistic framework for how DISC assembly initiates apoptosis and amplifies signaling via higher-order oligomerization.
    Keywords:  FADD; Fas; caspase; cryo-EM; death domain
    DOI:  https://doi.org/10.1073/pnas.2504819122
  12. Inflamm Res. 2025 Jun 03. 74(1): 90
      The brain's process of creating neural networks that affect functionality or performance is referred to as neurodevelopment. A person's capacity to learn and remember, pay attention, regulate their emotions, socialize, exercise and self-control are just a few of the cognitive and motor abilities that can be affected by abnormal brain development. Numerous neurodevelopmental diseases have been functionally related to abnormalities in innate immune signaling networks. Innate immunity is in charge of the defense of humans against pathogens and tissue damage by triggering inflammation, mainly through sensing pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). Some of these inflammatory processes have been shown to be mediated by large multiprotein complexes called inflammasomes which are present in cytosol and play important roles in the immune system. Due to its role in defense against infectious agents, bacteria, viruses, and fungi, NLRP3 is almost the most studied and well-known member of inflammasomes. The involvement of NLRP3 in inflammatory illnesses is evident due to the wide range of triggers and its intricate signaling pathways. In disorders with neurodevelopmental underpinnings, such as autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), schizophrenia (SCZ), obsessive compulsive disorder (OCD), bipolar disorder (BD), Tourette syndrome (TS), etc., neuroinflammation plays a significant role in their pathophysiology. For these reasons, we reviewed the roles of NLRP3 in various neurodevelopmental disorders below.
    Keywords:  Autism spectrum disorder; Bipolar disorder; NLRP3; Neurodevelopment; Schizophrenia
    DOI:  https://doi.org/10.1007/s00011-025-02052-1
  13. Eur J Med Chem. 2025 May 22. pii: S0223-5234(25)00548-3. [Epub ahead of print]295 117783
      Targeting NLRP3 inflammasome has emerged as a promising therapeutic strategy for various inflammatory diseases. In this work, to discover safe and effective novel NLRP3 inhibitors, we designed and synthesized a series of new non-sulfonylurea NLRP3 inflammasome inhibitors. Among them, the representative compound B6 specifically and potently inhibited the activation of NLRP3 inflammasome with an IC50 of 10.69 nM, exhibiting better potency compared to MCC950 (IC50 = 14.08 nM). Furthermore, B6 showed improved tolerability in both human hepatic cell lines and mouse primary hepatocytes (cell viability >95 %) compared to MCC950 (cell viability <82 %) at 500 μM. Mechanistically, B6 did not inhibit LPS-induced priming of the NLRP3 inflammasome, but significantly blocked NLRP3 inflammasome assembly by directly binding to NLRP3 and disrupting the NEK7-NLRP3 interaction. In vivo studies demonstrated that B6 was more effective than MCC950 in multiple NLRP3-driven diseases model, including systemic inflammation, peritonitis, and colitis. These findings suggest that B6 can be developed as a promising drug candidate for treating NLRP3-driven diseases.
    Keywords:  Inflammatory diseases; NLRP3 inflammasome inhibitors; Non-sulfonylurea; Structural modification
    DOI:  https://doi.org/10.1016/j.ejmech.2025.117783
  14. Cell Death Dis. 2025 Jun 02. 16(1): 426
      Receptor-interacting serine/threonine kinase 1 (RIPK1) is a pivotal protein controlling cell death and inflammation. RIPK1 is an attractive therapeutic target, given that the inhibition of RIPK1 kinase activity has been shown to be effective in animal models of human diseases such as autoimmune and neurodegenerative diseases. Here, we screened a collection of drugs with structural similarity to necrostatin-1 (Nec-1), an inhibitor of RIPK1, to assess their abilities to regulate RIPK1-mediated immunogenic cell death. Through this small-scale screening of drugs from ongoing clinical trials and FDA-approved drugs, we discovered that the drug phensuximide could prevent necroptosis by targeting RIPK1 kinase activity. Importantly, phensuximide, which has already been approved by the FDA for the treatment of epilepsy, effectively prevents the kinase activity of RIPK1 without affecting the NF-κB and MAPK pathways. The potency of phensuximide is that it protects against both LPS- and TNF-induced systemic inflammatory response syndrome (SIRS), which are sepsis models involving RIPK1 kinase activity. Our findings suggest that phensuximide may serve as a promising strategy for targeting RIPK1-mediated diseases.
    DOI:  https://doi.org/10.1038/s41419-025-07754-2
  15. Front Biosci (Landmark Ed). 2025 May 20. 30(5): 27231
      Inborn errors of immunity (IEIs) are a group of more than 485 disorders that impair immune development and function with variable reported incidence, severity, and clinical phenotypes. A subset of IEIs blend increased susceptibility to infection, autoimmunity, and malignancy and are known collectively as primary immune regulatory disorders (PIRDs). Programmed cell death, or apoptosis, is crucial for maintaining the balance of lymphocytes. Genetic-level identification of several human inherited diseases with impaired apoptosis has been achieved, such as autoimmune lymphoproliferative syndrome (ALPS), caspase-8 deficiency state (CEDS), X-linked lymphoproliferative syndrome (XLP), and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway disorders. The consequences of this disease are manifested by abnormal lymphocyte accumulation, resulting in clinical features such as lymphadenopathy, hepatomegaly, splenomegaly, and an increased risk of lymphoma. Additionally, these disorders are often associated with autoimmune disease, particularly involving blood cells. Understanding the molecular pathogenesis of these conditions has provided critical insights into the signaling pathways that regulate apoptosis and lymphocyte activation, shedding light on mechanisms of immune dysregulation. This review focuses on the intersection between apoptosis, autoimmunity, and lymphoproliferation, discussing how dysregulation contributes to the development of these immune disorders. These conditions are characterized by excessive lymphocyte accumulation, autoimmunity, and/or immunodeficiency. Understanding their molecular pathogenesis has offered new insights into the signaling mechanisms that regulate apoptosis and lymphocyte activation.
    Keywords:  X-linked lymphoproliferative disease (XLP); apoptosis; autoimmune lymphoproliferative syndrome (ALPS); inborn errors of immunity (IEI); primary immune deficiency (PID)
    DOI:  https://doi.org/10.31083/FBL27231
  16. Hum Mol Genet. 2025 Jun 05. pii: ddaf066. [Epub ahead of print]
      Systemic Lupus Erythematosus (SLE) is a complex autoimmune disorder characterized by loss of self-tolerance to nucleic acids, resulting in multisystem inflammation and organ damage. The genetic underpinning of SLE spans from common risk variants with modest effect sizes to rare monogenic mutations with high penetrance. Recent advances in next-generation sequencing and transcriptomic profiling have illuminated the central role of innate immune pathways in disease pathogenesis. This review synthesizes emerging evidence regarding innate immunity in SLE, with emphasis on toll-like receptor (TLR) signaling and regulatory mechanisms, NLRP3 inflammasome activation, myeloid cell dysregulation, and microbiome-immune interactions. Understanding these pathways provides a foundation for developing targeted therapeutics that may offer precision medicine approaches for this heterogeneous disease.
    Keywords:  Inflammasome; Lupus; Microbiome; Myeloid cells; Toll like Receptors
    DOI:  https://doi.org/10.1093/hmg/ddaf066
  17. Cytokine Growth Factor Rev. 2025 May 22. pii: S1359-6101(25)00051-6. [Epub ahead of print]
      Interleukin (IL)-1β is a pro-inflammatory cytokine largely produced by cells of the innate immune system in response to tissue damage or to the presence of pathogens. IL-1β-driven inflammation is an established contributor to many disease processes and thus there is great interest in understanding its regulation. This review focusses on the mechanisms involved in the secretion of IL-1β by macrophages. As IL-1β secretion does not follow the conventional ER-Golgi secretory pathway, various mechanisms for IL-1β secretion are proposed, with evidence suggesting that multiple pathways may exist. This review considers the proposed mechanisms determining the secretory pathway of IL-1β.
    Keywords:  Gasdermin D, Unconventional protein secretion; IL-1β; Inflammation; Pyroptosis
    DOI:  https://doi.org/10.1016/j.cytogfr.2025.05.005
  18. Cell Death Discov. 2025 Jun 03. 11(1): 263
      BH3-only proteins are a subgroup of the pro-apoptotic Bcl-2 family proteins. They initiate apoptosis by interacting with the multidomain pro- and anti-apoptotic Bcl-2 family proteins. SYNE2 encodes multiple nesprin-2 (Nes2) isoforms of which the most abundant and the largest is the nuclear envelope protein nesprin-2 giant (Nes2G). Nes2G is a component of the nuclear envelope Linker of Nucleoskeleton and Cytoskeleton (LINC) complex that connects the nucleus and the cytoskeleton. Previously, we showed that Nes2 has pro-apoptotic activity. We now show that Nes2G can bind multidomain pro-apoptotic and anti-apoptotic Bcl-2 family proteins and contains two BH3-like motifs near its N- and C-termini. Molecular modeling predicts that these BH3-like motifs have amphipathic α-helix structures and can dock onto the canonical groove of Bax and anti-apoptotic proteins as well as the trigger site of Bax. A chimeric tBid with its BH3 domain replaced with the C-terminal Nes2 BH3-like domain binds to Bax in cells. Furthermore, Nes2 BH3-like motif-containing fragments from the N- and the C-termini bind both pro-apoptotic and anti-apoptotic Bcl-2 proteins and promote cytochrome c release (indicative of apoptosis). Our results suggest that Nes2 acts as a BH3-only protein that regulates apoptosis by binding to the multidomain Bcl-2 family proteins.
    DOI:  https://doi.org/10.1038/s41420-025-02534-5