Inflammasome-activated gasdermin D causes pyroptosis by forming membrane pores

Molecular mechanisms of programmed cell death and potential targeted pharmacotherapy in ischemic stroke (Review)

Stroke poses a threat to the elderly, being the second leading cause of death and the third leading cause of disability worldwide. Ischemic stroke (IS), resulting from arterial occlusion, accounts for ~85% of all strokes. The pathophysiological processes involved in IS are intricate and complex. Currently, tissue plasminogen activator (tPA) is the only Food and Drug Administration‑approved drug for the treatment of IS. However, due to its limited administration window and the risk of symptomatic hemorrhage, tPA is applicable to only ~10% of patients with stroke. Additionally, the reperfusion process associated with thrombolytic therapy can further exacerbate damage to brain tissue. Therefore, a thorough understanding of the molecular mechanisms underlying IS‑induced injury and the identification of potential protective agents is critical for effective IS treatment. Over the past few decades, advances have been made in exploring potential protective drugs for IS. The present review summarizes the specific mechanisms of various forms of programmed cell death (PCD) induced by IS and highlights potential protective drugs targeting different PCD pathways investigated over the last decade. The present review provides a theoretical foundation for basic research and insights for the development of pharmacotherapy for IS.

Discovery of a novel Thiazole amide inhibitor of Inflammasome and Pyroptosis pathways

Upon the activation of inflammasomes, inflammatory caspases cleave and activate gasdermin D (GSDMD), leading to pore formation that causes cell membrane rupture and amplifies downstream inflammatory responses. Dysregulated inflammasome activation and pyroptosis signaling pathways are implicated in numerous inflammatory diseases. In our work, a set of novel thiazole amide compounds with inhibitory activity against NLRP3 inflammasome-induced pyroptosis was identified. Of all the compounds tested, compound 21 demonstrated the most potent anti-pyroptotic effects. It suppressed GSDMD cleavage and decreased IL-1β and lactate dehydrogenase (LDH) release in a concentration-dependent manner. Compound 21 bound to NLRP3 protein and increased the thermal stability of NLRP3 concentration-dependently. The molecular docking and dynamics simulations revealed that compound 21 binds to the NLRP3 protein's active site, suppressing inflammasome activation. Further investigations showed that compound 21 also partially blocked upstream NF-κB signaling and downstream GSDMD N-terminal domain (GSDMD-NT) oligomerization, which explains its broad inhibitory effects on pyroptosis driven by multiple inflammasomes. Overall, this study presents a promising thiazole amide compound with inhibitory activity against inflammasome activation and subsequent pyroptosis, warranting further exploration.

Carbon monoxide gas molecules: Therapeutic mechanisms in radiation-induced lung injury

Radiation therapy (RT) remains an essential treatment modality for lung cancer, yet its effectiveness is frequently hindered by radiation-induced lung injury (RILI), a common outcome of modern therapeutic regimens. With the aim of addressing this challenge, a novel nanocomposite, Au@mSiO2@Mn(CO)5Br (ASMB), was synthesized with Au@mSiO2 as the carrier and Mn(CO)5Br as the functional component. The gold nanorods (Au rods) core generates reactive oxygen species (ROS) under X-ray irradiation, which then activates Mn(CO)5Br to release carbon monoxide (CO) locally within the lung during radiotherapy. The released CO then diffuses to surrounding tissues, inhibiting the excessive accumulation of ROS, thereby preventing damage to normal cells caused by ROS generated in a short period of time. Meanwhile, the released manganese ions (Mnn+) catalyze the conversion of hydrogen peroxide (H2O2) in the microenvironment into oxygen (O2). In vitro experiments demonstrated that the release of CO markedly attenuated radiation-induced ROS production, thereby inhibiting the activation of the NLRP3 inflammasome and reducing the levels of inflammatory cytokines and pyroptosis-related proteins. Moreover, it downregulated the expression of fibrosis-associated proteins, including TGF-β1 and α-SMA. Additionally, CO facilitated DNA damage repair, thereby mitigating radiation-induced tissue injury. In the RILI model, the ASMB NPs-treated lungs exhibited notably reduced pulmonary edema, congestion, and inflammatory cell infiltration, primarily by inhibiting NLRP3 inflammasome-dependent pyroptosis and reducing levels of inflammation and fibrosis markers. The release of O2 further mitigates local tissue hypoxia, enhancing the effectiveness of radiotherapy. Overall, ASMB NPs provide a promising alternative for the treatment of RILI and a potential therapeutic strategy to improve the efficacy of radiotherapy.

Cell death and cancer: Metabolic interconnections

Recent findings in the cell death field have transformed our understanding of the interplay between metabolism and cell death in the context of cancer. In this review, we discuss the relationships between metabolism and the cell death pathways of apoptosis, necroptosis, pyroptosis, and ferroptosis, with a particular focus on recent advancements. We will also explore the regulation of metabolism by the BCL-2 family and the participation of oncometabolites in the regulation of cell death. Finally, we examine the emerging links between cell death signaling and cellular persistence. As we highlight in this review, the intersection of metabolic and cell death pathways has implications for cancer cell survival, treatment resistance, and the tumor microenvironment.

Sinomenine ameliorates vascular calcification by inhibiting pyroptosis-related molecules and AEG-1 in chronic kidney disease

BACKGROUNDS

Vascular calcification (VC) is an important factor for mortality in chronic kidney disease (CKD). Sinomenine can suppress atherosclerosis. However, its role in CKD-associated-vascular calcification and mechanisms remain unclear.

METHODS

Sprague-Dawley rats that were fed with high-phosphorus diet and adenine suspension were used to construct the calcification model in CKD. Calcification from rats or cells were analyzed using micro-CT and alizarin red staining. Levels of NLRP-3, Caspase-1, GSDMD and AEG-1 were measured by qPCR, western blotting, and immunohistochemistry. Transfection experiment was used in function study.

RESULTS

CKD rats fed with high-phosphorus diet and adenine suspension increased aortic calcification over time. Micro-CT images revealed the distribution and severity of the calcification, and these lesions were significantly decreased in the Sinomenine (SIN) group. This is similar to the results obtained for the AR staining of translucent samples. Additionally, aortas from CKD rats that were treated with 30 mg/kg/d SIN showed a down-regulation of NLRP3, Caspase-1, GSDMD and AEG-1 expression compared with aortas from CKD rats. Sinomenine exhibited similar inhibitory effects on NLRP3 and Caspase-1 as VX-765 in the aortas of uremic rats and calcified VSMCs. Moreover, VSMC transfected with pc-AEG-1 accelerated the VSMC calcification while transfection with si-AEG-1 ameliorated the calcification. Importantly, sinomenine abolished the VSMC calcification induced by AEG-1 overexpression under the uremia condition.

CONCLUSIONS

Our findings indicated that sinomenine could ameliorate vascular calcification in CKD rats and inhibit hyperphosphatemia-induced calcifying VSMCs via inhibiting pyroptosis-related molecules and AEG-1. Sinomenine might serve as an effective therapeutic agent for CKD-associated vascular calcification.

Tumor-targeting nanomaterials based on metal-organic frameworks mediate tumor immunotherapy by promoting cuproptosis and pyroptosis in hepatocellular carcinoma cells

Activating a robust immune response is an effective strategy for achieving tumor eradication. In this study, copper-based metal-organic framework nanoparticles (referred to as FA-PZ@MOF NPs), which have the ability to simultaneously induce cuproptosis and pyroptosis in tumor cells, were designed to utilize the synergistic effects of cuproptosis and pyroptosis to trigger immunogenic cell death (ICD). This can inhibit tumor growth, migration, and metastasis while enabling efficient antitumor immunotherapy. The nano inducer targets hepatocellular carcinoma tumor cells via folic acid, dissociates and releases copper ions in the tumor microenvironment (TME), which has a high glutathione concentration, leading to copper ion overload, thereby mediating cuproptosis. Additionally, the released ZnO2 generates substantial amounts of H2O2 and Zn2+ in the acidic environment, enhancing the Cu2+-based Fenton-like reaction for chemokinetic therapy. This exacerbates the reactive oxygen species (ROS) storms and mitochondrial damage, and combined with the action of Polyphyllin VI (PPVI), induces pyroptosis and cuproptosis. This multilayered interaction strategy also triggers robust ICD while inhibiting hepatocellular carcinoma tumor metastasis and invasion.

Molecular mechanism of PANoptosis and programmed cell death in neurological diseases

PANoptosis represents a highly coordinated inflammatory programmed cell death governed by the assembly and activation of PANoptosome, which strategically integrate core molecular elements from pyroptosis, apoptosis, and necroptosis. The triple-component cell death pathways set themselves apart from alternative regulated cell death mechanisms through their unique capacity to concurrently integrate and process molecular signals derived from multiple death-signaling modalities, thereby coordinating a multifaceted cellular defense system against diverse pathological insults. Pathogen-associated molecular patterns synergistically interact with cytokine storms, and oncogenic stress to active PANoptosis, establishing this programmed cell death pathway as a critical nexus in inflammatory pathogenesis and tumor immunomodulation. This molecular crosstalk highlights PANoptosis as a promising therapeutic target for managing immune-related disorders and malignant transformation. Emerging evidence links PANoptosis to neuroinflammatory disorders through dysregulated crosstalk between programmed death pathways (apoptosis, necroptosis, pyroptosis) and accidental necrosis, driving neuronal loss and neural damage. Single-cell transcriptomics reveals spatially resolved PANoptosis signatures in Alzheimer's hippocampal microenvironments and multiple sclerosis demyelinating plaques, with distinct molecular clusters correlating to quantifiable neuroinflammatory metrics. Emerging PANoptosis-targeted therapies show preclinical promise in alleviating neurovascular dysfunction while preserving physiological microglial surveillance functions. Accumulating evidence linking dysregulated cell death pathways (particularly PANoptosis) to neurological disorders underscores the urgency of deciphering its molecular mechanisms and developing precision modulators as next-generation therapies. This review systematically deciphers PANoptosome assembly mechanisms and associated cell death cascades, evaluates their pathological roles in neurological disorders through multiscale regulatory networks, and proposes PANoptosis-targeted therapeutic frameworks to advance precision neurology.

The immune-modulatory dynamics of exosomes in preeclampsia

This review delves into the role of exosomes in immune regulation within the context of preeclampsia (PE), a pregnancy condition marked by high blood pressure and widespread inflammation. PE hampers the invasion of trophoblasts and disrupts placental function, contributing to inflammation and maternal organ dysfunction. Exosomes are small extracellular vesicles that mediate cell-to-cell communication by transferring proteins, lipids, and nucleic acids. This review highlights their role in immune regulation during pregnancy, especially their altered behavior in PE. Normally, exosomes support communication between the mother and fetus, promoting immune tolerance. In PE, however, exosomal activity and content undergo significant changes, potentially intensifying the inflammatory state. Further investigation into the in vivo immune-modulatory actions of exosomes, especially those from preeclamptic placentas, may provide insights into the pathogenesis of PE and uncover novel therapeutic targets for treatment.

Mitigation of nicotine-induced podocyte injury through inhibition of thioredoxin interacting protein

Nicotine has been reported to initiate NLRP3 inflammasome formation and activation in different pathological conditions. The current study assessed whether thioredoxin-interacting protein (TXNIP) mediates nicotine-induced NLRP3 inflammasome activation and consequent podocyte injury. Co-immunoprecipitation analysis demonstrated that nicotine-induced TXNIP/NLRP3 interaction in podocytes relative to control groups. However, pre-treatment with TXNIP inhibitors, verapamil (Vera) or SRI-37330 (SRI) attenuates nicotine-induced TXNIP/NLRP3 interaction. Confocal microscopic analysis showed that nicotine treatment significantly increased the colocalization of Nlrp3 with Asc, Nlrp3 with caspase-1 and Nlrp3 with TXNIP in podocytes compared to control cells. Pretreatment with TXNIP inhibitor Vera or SRI abolished nicotine-induced Nlrp3/Asc, Nlrp3/caspase-1 or Nlrp3/TXNIP colocalization. Correspondingly, nicotine treatment significantly increased the caspase-1 activity and IL-1β production compared to control cells. However, prior treatment with TXNIP inhibiting Vera or SRI significantly attenuated the nicotine-induced caspase-1 activity and IL-1β production. Further immunofluorescence analysis showed that nicotine treatment significantly decreased podocin and nephrin expression compared to control cells. However, pretreatment with TXNIP inhibiting Vera or SRI attenuated the nicotine-induced podocin and nephrin reduction. In addition, confocal, flow cytometry and biochemical analysis showed that nicotine treatment significantly increased desmin expression, apoptosis and cell permeability compared to control cells. However, prior treatment with TXNIP inhibiting Vera or SRI significantly attenuated the nicotine-induced desmin expression, apoptosis and cell permeability. Taken together, our results demonstrate that TXNIP/NLRP3 interaction constitutes a potentially key signalling mechanism driving nicotine-induced NLRP3 inflammasome formation, activation and subsequent podocyte damage.

LncRNA16 inhibits pyroptosis and promotes platinum resistance in non-small cell lung cancer by sponging miRNA1827 to regulate MBD3/GSDME expression

BACKGROUND

Platinum-based chemotherapy is the standard first-line cancer treatment. However, patients experience relapses due to chemoresistance. We found that long non-coding RNA 16 (lncRNA16) promotes platinum resistance and inhibits cell death in non-small cell lung cancer (NSCLC). However, the type of cell death inhibited by lncRNA16 remains unknown.

METHODS

The biological roles of lncRNA16 and microRNA 1827 (miRNA1827) in cell proliferation and colony formation were determined using functional experiments. Dual-luciferase reporter and RNA immunoprecipitation assays were performed to confirm the interactions between lncRNA16 and miRNA1827. In vivo patient-derived tumor xenograft (PDX) models were used to investigate the effects of miRNA1827 agomir on platinum resistance.

RESULTS

Pyroptosis was inhibited in platinum-resistant NSCLC cells. LncRNA16 contributed to the expression of methyl-CpG binding domain protein 3 (MBD3) by sponging miRNA1827, thereby inhibiting gasdermin E (GSDME) expression, which inhibited pyroptosis in platinum-resistant NSCLC. The miRNA1827 agomir repressed platinum resistance in vitro experiments and in vivo PDX models.

CONCLUSION

We identified a novel function of lncRNA16 in inhibiting pyroptosis and proposed an effective therapeutic drug, the miRNA1827 agomir, for chemosensitization. This study offers a potential strategy for treating patients with NSCLC, especially those with platinum resistance.

CEBPD is a pivotal factor for the activation of NLRP3 inflammasome in traumatic brain injury

Traumatic brain injury (TBI) is a significant global health concern and a leading cause of mortality and disability worldwide. Neuroinflammation is a pivotal pathological mechanism underlying secondary brain injury following TBI. CCAAT enhancer-binding protein-delta (CEBPD), a transcription factor necessary for regulating immune and inflammatory responses, plays an important role in the progression of neuroinflammatory disorders. However, the role of CEBPD in the prognosis of TBI needs to be determined. We found that the expression of CEBPD increased significantly in TBI patients and animal models, as well as in the HT-22 neuron mechanical scratch injury model. The inhibition of CEBPD by in vivo siRNA effectively suppressed neuronal death, brain edema, and brain contusion volume and alleviated neurofunctional deficits. Knocking down CEBPD considerably inhibited the activation of the neuronal NLRP3 inflammasome, downregulated the expression of the GSDMD N-terminal fragment, and reduced the production of IL-1β and IL-18, significantly mitigating neuronal pyroptosis after TBI. Increasing CEBPD levels led to the activation of the NLRP3 inflammasome and neuronal pyroptosis in the mechanical scratch injury cell model. We also determined that the NLRP3 inflammasome activated by nigericin depended on the CEBPD pathway following TBI. Our results suggested that CEBPD may serve as a pivotal factor in promoting neuronal pyroptosis and that inhibiting CEBPD might be a promising strategy for treating TBI.

4-octyl itaconate reduces human NLRP3 inflammasome constitutive activation with the cryopyrin-associated periodic syndrome p.R262W, p.D305N and p.T350M variants

Cryopyrin-associated periodic syndrome (CAPS) is a condition characterized by dominant genetic variants in the NLRP3 gene, which lead to the formation of constitutively active inflammasomes. These inflammasomes play a crucial role in CAPS patients' inflammatory episodes, these being primarily driven by the production of interleukin (IL)-1b. Although treatment with IL-1 blockers is effective for CAPS, some patients develop refractory responses and adverse reactions to these therapies. Consequently, there is a need for novel treatments for CAPS patients. Promising candidates are the derivatives of itaconate, which have been shown to impair NLRP3 inflammasome activation and IL-1β release in blood mononuclear cells from CAPS patients. In this study, we provide insight into the inhibitory mechanisms by which the itaconate derivative 4-octyl itaconate (4-OI) acts on NLRP3 that has different gain-of-function mutations (p.R262W, p.D305N and p.T350M) associated with CAPS. Notably, 4-OI effectively blocks the basal auto-activation of the inflammasome formed by NLRP3 p.R262W, p.D305N and p.T350M variants, which in turn reduces caspase-1 activation, gasdermin D processing, and IL-18 release. Furthermore, after lipopolysaccharide priming of macrophages, 4-OI also decreases IL-1β gene expression and release. Overall, 4-OI impairs CAPS-associated inflammasome function at multiple levels, meaning that therapeutic agents based on itaconate could be a promising therapeutic approach to managing inflammatory episodes in CAPS patients carrying p.R262W, p.D305N or p.T350M variants.

Anti-Inflammasome Effect of Impressic Acid on Diesel Exhaust Particulate Matter-Induced NLRP1 Inflammasome via the Keap1/p62/Nrf2-Signaling Pathway in Keratinocytes

Diesel exhaust particulate (DEP) is widely recognized to weaken lung function and skin diseases. When the skin, which defends against external factors, is exposed to PM2.5, various chronic inflammatory diseases occur. When keratinocytes recognize harmful signals, they synthesize the NOD-like receptor protein 1 (NLRP1) inflammasome. DEP enhances NF-κB signaling and NLRP1 inflammasome expression through the interaction of TXNIP with NLRP1 in keratinocytes. Although many studies have reported the anti-inflammatory and antioxidant characteristics of Impressic acid (IPA), the umbrella consequences of IPA for PM2.5-influenced inflammasomes and the associated mechanisms remain unknown. Therefore, this study aimed to examine the protective function of IPA against inflammation in human keratinocytes. IPA attenuated the NLRP1 expression, caspase-1, IL-1β actuation, and NF-κB and IκB phosphorylation induction by DEP. IPA upregulated the Nrf2, HO-1, and NQO1 expression through CaMKKβ, AMPK, and GSK3β phosphorylation. Also, IPA led to the elevation of p62 and the degradation of the Keap1 protein. ML385 reversed the suppressive effect of IPA on the NLRP1 inflammasome, which was enhanced by DEP, and NAC counteracted the effect of ML385. These findings indicate that IPA can suppress inflammation induced by PM2.5 by expressing antioxidant enzymes through the Keap1/p62/Nrf2-signaling pathway in human keratinocytes.

Deciphering the NLRP3 inflammasome in diabetic encephalopathy: Molecular insights and emerging therapeutic targets

Diabetic encephalopathy (DE) is a neurological complication characterized by neuroinflammation, cognitive impairment, and memory decline, with its pathogenesis closely linked to the activation of the NLRP3 inflammasome. As a central regulator of the innate immune system, the NLRP3 inflammasome plays a pivotal role in DE progression by mediating neuroinflammation, pyroptosis, mitochondrial dysfunction, oxidative stress, endoplasmic reticulum (ER) stress, and microglial polarization. This review systematically explores the molecular mechanisms by which the NLRP3 inflammasome contributes to DE, focusing on its role in neuroinflammatory cascades and neuronal damage, as well as the diabetes-associated physiological changes that exacerbate DE pathogenesis. Furthermore, we summarize emerging therapeutic strategies targeting the NLRP3 inflammasome, including small-molecule inhibitors and bioactive compounds derived from traditional herbal medicine, highlighting their potential for DE treatment. These findings not only advance our understanding of DE but also provide a foundation for developing NLRP3-targeted pharmacological interventions.

Pyroptosis and its role in intestinal ischemia-reperfusion injury: a potential therapeutic target

Intestinal ischemia-reperfusion injury (II/RI) is a critical acute condition characterized by complex pathological mechanisms, including various modes of cell death. Among these, pyroptosis has garnered significant attention in recent years. This review explores the characteristics, molecular mechanisms, and implications of pyroptosis in II/RI, with a focus on therapeutic strategies targeting the pyroptosis pathway. Key processes such as NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation, caspase-1 activation, and gasdermin D (GSDMD)-mediated membrane pore formation are identified as central to pyroptosis. Compounds like MCC950, CY-09, metformin, and curcumin have shown promise in attenuating II/RI in preclinical studies by modulating these pathways. However, challenges remain in understanding non-canonical pyroptosis pathways, unraveling the exact mechanisms of GSDMD-induced pore formation, and translating these findings into clinical applications. Addressing these gaps will be crucial for developing innovative and effective treatments for II/RI.

NLRP11 is required for canonical NLRP3 and non-canonical inflammasome activation during human macrophage infection with mycobacteria

The NLRP11 protein is only expressed in primates and participates in the activation of the canonical NLRP3 and non-canonical NLRP3 inflammasome activation after infection with gram-negative bacteria. Here, we generated a series of defined NLRP11 deletion mutants to further analyze the role of NLRP11 in NLRP3 inflammasome activation. Like the complete NLRP11 deletion mutant (NLRP11-/-), the NLRP11 mutant lacking the NAIP, C2TA, HET-E, and TP1 (NACHT) and leucine-rich repeat (LRR) domains (NLRP11∆N_LRR) showed reduced activation of the canonical NLRP3 inflammasome, whereas a pyrin domain mutant (NLRP11∆PYD) had no effect on NLRP3 activation. The NLRP11-/- and NLRP11∆N_LRR mutants, but not the NLRP11∆PYD mutant, also displayed reduced activation of caspase-4 during infection with the intracytosolic, gram-negative pathogen Shigella flexneri. We found that the human-adapted, acid-fast pathogen Mycobacterium tuberculosis and the opportunistic pathogen Mycobacterium kansasii both activate the non-canonical NLRP11 inflammasome in a caspase-4/caspase-5-dependent pathway. In conclusion, we show that NLRP11 functions in the non-canonical caspase-4/caspase-5 inflammasome activation pathway and the canonical NLRP3 inflammasome pathway and that NLRP11 is required for full recognition of mycobacteria by each of these pathways. Our work extends the spectrum of bacterial pathogen recognition by the non-canonical NLRP11-caspase4/caspase-5 pathway beyond gram-negative bacteria.IMPORTANCEThe activation of inflammasome complexes plays a crucial role in intracellular pathogen detection. NLRP11 and caspase-4 are essential for recognizing lipopolysaccharide (LPS), a molecule found in gram-negative bacteria such as the human pathogens Shigella spp., which activate both canonical NLRP3 and non-canonical inflammasome pathways. Through a series of deletion mutants, we demonstrate that the NACHT and LRR domains of NLRP11, but not its pyrin domain, are critical for detection of S. flexneri. Notably, our research reveals that the acid-fast bacterium M. tuberculosis is also detected by NLRP11 and caspase-4, despite not producing LPS. These findings significantly expand the range of pathogens recognized by NLRP11 and caspase-4 to now include acid-fast bacteria that do not contain LPS and underscore the versatility of these innate immune components in pathogen detection.

Bone marrow microenvironment in myelodysplastic neoplasms: insights into pathogenesis, biomarkers, and therapeutic targets

Myelodysplastic neoplasms (MDS) represent a heterogeneous group of malignant hematopoietic stem and progenitor cell (HSPC) disorders characterized by cytopenia, ineffective hematopoiesis, as well as the potential to progress to acute myeloid leukemia (AML). The pathogenesis of MDS is influenced by intrinsic factors, such as genetic insults, and extrinsic factors, including altered bone marrow microenvironment (BMM) composition and architecture. BMM is reprogrammed in MDS, initially to prevent the development of the disease but eventually to provide a survival advantage to dysplastic cells. Recently, inflammation or age-related inflammation in the bone marrow has been identified as a key pathogenic mechanism for MDS. Inflammatory signals trigger stress hematopoiesis, causing HSPCs to emerge from quiescence and resulting in MDS development. A better understanding of the role of the BMM in the pathogenesis of MDS has opened up new avenues for improving diagnosis, prognosis, and treatment of the disease. This article provides a comprehensive review of the current knowledge regarding the significance of the BMM to MDS pathophysiology and highlights recent advances in developing innovative therapies.

PDE10A Inhibition Reduces NLRP3 Activation and Pyroptosis in Sepsis and Nerve Injury

Cell death and inflammation are key innate immune responses, but excessive activation can cause tissue damage. The NLRP3 inflammasome is a promising target for reducing inflammation and promoting recovery. Immunometabolism regulates NLRP3 responses in neurological and inflammatory diseases through cyclic nucleotide signaling. Targeting phosphodiesterases (PDEs), which hydrolyze cAMP and cGMP, offer a novel approach to mitigate inflammation. While 14 PDE inhibitors are FDA-approved, PDE10A's role in NLRP3 inflammasome activation remains unclear. This study investigates the effects of PDE10A inhibition on inflammasome-driven inflammation using two PDE10A inhibitors, MP-10 and TP-10, in macrophage and animal models of sepsis and traumatic nerve injury. Our results show that PDE10A inhibition reduces inflammasome activation by preventing ASC speck formation and by lowering levels of cleaved caspase-1, gasdermin D, and IL-1β, which are key mediators of pyroptosis. In the sepsis model, MP-10 significantly reduced inflammation, decreased plasma IL-1β, alleviated thrombocytopenia, and improved organ damage markers. In the nerve injury model, PDE10A inhibition enhanced motor function recovery and reduced muscle atrophy-related gene expression. These findings suggest that PDE10A inhibition could be a promising therapeutic approach for inflammatory and neuromuscular injuries. Given MP-10's established safety in human trials, Phase 2 clinical studies for sepsis and nerve injury are highly promising.

Phagosome-mediated anti-bacterial immunity is governed by the proton-activated chloride channel in peritoneal macrophages

The success of phagosome degradation relies on the ability of phagocytes to regulate the maturation of phagosomes. However, its underlying molecular mechanisms remain poorly understood. Here, we identify the proton-activated chloride (PAC) channel as a key negative regulator of phagosome maturation. PAC deletion enhanced phagosomal acidification and protease activities, leading to augmented bacterial killing in large peritoneal macrophages (LPMs) upon Escherichia coli infection in mice. Surprisingly, phagosome degradation also stimulated STING-IRF3-interferon responses and inflammasome activation in LPMs, both of which are enhanced upon PAC deletion. The increased inflammasome activation induced the release of cleaved gasdermin D, which localized to the surface of bacteria in the peritoneum and further contributed to their killing. Finally, enhanced bacterial clearance by PAC-deficient LPMs reduced proinflammatory immune cell infiltration and peritoneal inflammation, resulting in improved survival in mice. Our study thus provides new insights into the molecular mechanism of phagosome maturation and the dynamics of host defense response following phagosome-mediated bacterial degradation in peritoneal macrophages.

Summary

The PAC channel mediates phagosome maturation during bacterial infection in macrophages. PAC deletion promotes phagosome-mediated STING-interferon signaling and inflammasome-mediated gasdermin D secretion during bacterial infection in peritoneal macrophages.

Mitochondrial reactive oxygen species promote cancer metastasis and tumor microenvironment immunosuppression through gasdermin D

Although recent research has established that gasdermin D (GSDMD), a factor that drives pyroptosis, is essential for cell death and inflammation, its involvement in cancer metastasis has yet to be elucidated. In this study, GSDMD was significantly increased in lung neutrophils at the metastatic stage from a murine orthotropic 4T1 breast cancer model. Moreover, the N terminal domain from cleaved GSDMD exhibited a positive correlation with increased mitochondrial reactive oxygen species (mROS) and serum high mobility group box 1 (HMGB-1) levels. Mechanistically, mROS inhibition significantly suppressed GSDMD-N oligomerization and pore formation. In addition, the activation of GSDMD significantly enhanced the formation of neutrophil extracellular traps (NETs) following treatment with Cathepsin C. Within a murine orthotopic breast cancer model using 4T1 cell line, the inhibition of GSDMD through the application of LDC7559 significantly attenuated the metastatic spread of breast cancer to the lung. In addition, knockout of GSDMD reduced lung metastasis in E0771 intravenous injection murine model. Furthermore, inhibition of GSDMD reduced the number of myeloid derived suppressor cells (MDSC) in the metastatic lung of breast cancer mouse model, while concurrently increasing both the percentage and total cell count of CD8+ T cells, suggesting that mitochondrial dysfunction-dependent GSDMD activation promotes tumor microenvironment immunosuppression and NETs. GSDMD represents a promising therapeutic target for mitigating the metastatic progression of breast cancer to the lung.

The pathway of unconventional protein secretion involves CUPS and a modified trans-Golgi network

Compartment for unconventional protein secretion (CUPS), a compartment for secretion of signal sequence-lacking proteins, forms through COPI-independent extraction of membranes from early Golgi cisternae, lacks Golgi-specific glycosyltransferases, and requires phosphatidylinositol 4-phosphate (PI4P) for biogenesis, as well as phosphatidylinositol 3-phosphate for stability. Our findings demonstrate that Drs2, a PI4P effector from the trans-Golgi network (TGN), is essential for CUPS formation, specifically through its interaction with Rcy1, and Rcy1 is crucial for the unconventional secretion. Using 4D super-resolution confocal live imaging microscopy, we observed that CUPS interact with a modified TGN that contains Drs2 in addition to proteins Tlg2 and Snc2, which are necessary for membrane fusion. Notably, while CUPS remain stable, the modified TGN undergoes remodeling during the later stages of unconventional secretion. In summary, we suggest that CUPS and the modified TGN, without the function of COPII and COPI, participate in collecting and sorting unconventionally secreted proteins, reflecting the role of Golgi membranes in receiving cargo from the ER during conventional secretion.

Caspases: structural and molecular mechanisms and functions in cell death, innate immunity, and disease

Caspases are critical regulators of cell death, development, innate immunity, host defense, and disease. Upon detection of pathogens, damage-associated molecular patterns, cytokines, or other homeostatic disruptions, innate immune sensors, such as NLRs, activate caspases to initiate distinct regulated cell death pathways, including non-lytic (apoptosis) and innate immune lytic (pyroptosis and PANoptosis) pathways. These cell death pathways are driven by specific caspases and distinguished by their unique molecular mechanisms, supramolecular complexes, and enzymatic properties. Traditionally, caspases are classified as either apoptotic (caspase-2, -3, -6, -7, -8, -9, and -10) or inflammatory (caspase-1, -4, -5, and -11). However, extensive data from the past decades have shown that apoptotic caspases can also drive lytic inflammatory cell death downstream of innate immune sensing and inflammatory responses, such as in the case of caspase-3, -6, -7, and -8. Therefore, more inclusive classification systems based on function, substrate specificity, or the presence of pro-domains have been proposed to better reflect the multifaceted roles of caspases. In this review, we categorize caspases into CARD-, DED-, and short/no pro-domain-containing groups and examine their critical functions in innate immunity and cell death, along with their structural and molecular mechanisms, including active site/exosite properties and substrates. Additionally, we highlight the emerging roles of caspases in cellular homeostasis and therapeutic targeting. Given the clinical relevance of caspases across multiple diseases, improved understanding of these proteins and their structure-function relationships is critical for developing effective treatment strategies.

Targeting pyroptosis for cancer immunotherapy: mechanistic insights and clinical perspectives

Pyroptosis is a distinct form of programmed cell death characterized by the rupture of the cell membrane and robust inflammatory responses. Increasing evidence suggests that pyroptosis significantly affects the tumor microenvironment and antitumor immunity by releasing damage-associated molecular patterns (DAMPs) and pro-inflammatory mediators, thereby establishing it as a pivotal target in cancer immunotherapy. This review thoroughly explores the molecular mechanisms underlying pyroptosis, with a particular focus on inflammasome activation and the gasdermin family of proteins (GSDMs). It examines the role of pyroptotic cell death in reshaping the tumor immune microenvironment (TIME) involving both tumor and immune cells, and discusses recent advancements in targeting pyroptotic pathways through therapeutic strategies such as small molecule modulators, engineered nanocarriers, and combinatory treatments with immune checkpoint inhibitors. We also review recent advances and future directions in targeting pyroptosis to enhance tumor immunotherapy with immune checkpoint inhibitors, adoptive cell therapy, and tumor vaccines. This study suggested that targeting pyroptosis offers a promising avenue to amplify antitumor immune responses and surmount resistance to existing immunotherapies, potentially leading to more efficacious cancer treatments.

Cyclometalated iridium(III)-lonidamine conjugates: Mitochondrial targeting and pyroptosis induction

A series of cyclometalated Ir(III)-lonidamine (LND) complexes (Ir-LND-1-6) with the formula [Ir(C^N)2bpy(4-CH3-4'-CH2OLND)](PF6) (Ir-LND-1-3) and [Ir(C^N)2bpy(4-CH2OLND-4'-CH2OLND)](PF6) (Ir-LND-4-6) (C^N = 2-phenylpyridine (ppy, in Ir-LND-1 and Ir-LND-4), 2-(2-thienyl) pyridine (thpy, in Ir-LND-2 and Ir-LND-5) and 2-(2,4-difluorophenyl) pyridine (dfppy, in Ir-LND-3 and Ir-LND-6)), were designed and synthesized. 3-(4,5-dimethylthiazol-2-yl)-2,5-biphenyltetrazolium bromide (MTT) assay data showed that the cytotoxicity of Ir-LND-1-3 carry one LND moiety was superior to that of Ir-LND-4-6 with two LND moieties. Therefore, we selected Ir-LND-1-3 as model compounds to investigate the anti-tumor mechanism of the Ir(III)-LND system. The results showed that Ir-LND-1-3 could inhibit cancer cell migration and colony formation. In addition, Ir-LND-1-3 could penetrate into HeLa cells and localized to mitochondria, further disrupting mitochondrial membrane potential (MMP), increasing intracellular reactive oxygen species (ROS), and reducing intracellular adenosine triphosphate (ATP). Further exploration of anti-tumor mechanisms showed that pyroptosis was the main mode of Ir-LND-1-3 induced cell death, manifested as membrane perforation and swelling, activation of caspase-3 and cleavage of Gasdermin E (GSDME), as well as release of lactic dehydrogenase (LDH) and ATP. The pyroptosis induced by Ir-LND-1-3 also initiated immunogenic cell death (ICD) by triggering the release of calreticulin (CRT) and high mobility group protein b1 (HMGB1) on the cell surface.

STING regulates porphyromonas gingivalis lipopolysaccharide-induced pyroptosis and inflammatory response through the NF-κB/NLRP3 signaling pathway in human gingival fibroblasts

OBJECTIVE

The production of reactive oxygen species caused by antimicrobial response during periodontitis leads to the activation of NOD-like receptor protein 3 (NLRP3) inflammasome and pyroptosis. Stimulator of interferon genes (STING) has been found to be involved in regulating pyroptosis and inflammation in a variety of diseases. The present study aimed to investigate whether STING is involved in Porphyromonas gingivalis lipopolysaccharide (P.g LPS)-stimulated human gingival fibroblasts (HGFs) by regulating pyroptosis and inflammation.

DESIGN

After culturing and identifying HGFs, HGFs were treated with P.g LPS. Constructs of si-STING were transfected into HGFs, which were then stimulated with P.g LPS for 24 h. Subsequently, cell viability, pyroptosis, inflammation, oxidative stress and alterations in the STING/TANK-binding kinase 1 (TBK1)/interferon regulatory factor 3 (IRF3)/nuclear factor-kappaB (NF-κB)/NLRP3 signalling pathway were detected.

RESULTS

P.g LPS significantly enhanced STING expression in HGFs. Downregulation of STING rescued P.g LPS-enhanced pyroptosis, oxidative stress and inflammation in HGFs. Moreover, STING was found to bind directly to TBK1 to increase IRF3 phosphorylation and nuclear translocation of NF-κB, thus promoting NLRP3 inflammasome activation. Downregulation of STING rescued P.g LPS-enhanced TBK1/IRF3/NF-κB/NLRP3 pathway activation.

CONCLUSION

STING/TBK1/IRF3/NF-κB/NLRP3 is a key pathway governing pyroptosis, oxidative stress and inflammation of HGFs induced by LPS.

Pyroptosis: molecular mechanisms and roles in disease

Pyroptosis is a type of programmed necrosis triggered by the detection of pathogens or endogenous danger signals in the cytosol. Pyroptotic cells exhibit a swollen, enlarged morphology and ultimately undergo lysis, releasing their cytosolic contents - such as proteins, metabolites, and nucleic acids - into the extracellular space. These molecules can function as danger-associated molecular patterns (DAMPs), triggering inflammation when detected by neighboring cells. Mechanistically, pyroptosis is initiated by members of the gasdermin protein family, which were identified a decade ago as pore-forming executors of cell death. Mammalian gasdermins consist of a cytotoxic N-terminal domain, a flexible linker, and a C-terminal regulatory domain that binds to and inhibits the N-terminus. Proteolytic cleavage within the linker releases the N-terminal domain, enabling it to target various cellular membranes, including nuclear, mitochondrial, and plasma membranes, where it forms large transmembrane pores. Gasdermin pores in the plasma membrane disrupt the electrochemical gradient, leading to water influx and cell swelling. Their formation also activates the membrane protein ninjurin-1 (NINJ1), which oligomerizes to drive complete plasma membrane rupture and the release of large DAMPs. Since their discovery as pore-forming proteins, gasdermins have been linked to pyroptosis not only in host defense but also in various pathological conditions. This review explores the history of pyroptosis, recent insights into gasdermin activation, the cellular consequences of pore formation, and the physiological roles of pyroptosis.

Unraveling the mechanisms of NINJ1-mediated plasma membrane rupture in lytic cell death and related diseases

Plasma membrane rupture (PMR), the ultimate event during lytic cell death, releases damage-associated molecular patterns (DAMPs) that trigger inflammation and immune responses in the development of various diseases. Recent years have witnessed significant advances in understanding the PMR mediated by ninjurin1 (NINJ1) in different lytic cell death processes. NINJ1 oligomerizes and ruptures the membrane in pyroptosis and other lytic cell death, participating in the pathogenesis of multiple diseases. Although the membrane-permeabilizing function of NINJ1 is well recognized, the role of NINJ1 in different types of lytic cell death and its impact on multiple disease processes have yet to be fully elucidated. This review summarizes the latest advances in the mechanisms of NINJ1-mediated PMR, discusses the membrane-inducing activity of NINJ1 in different lytic cell death, explains the implications of NINJ1 in lytic cell death-related diseases, and lists the inhibitory strategies for NINJ1. We expect to provide new insights into targeting NINJ1 to suppress lytic cell death for therapeutic benefit, which may become a new strategy to control inflammatory cell lysis-related diseases.

NEK7 is an essential regulator in NLRP3 inflammasome assembly of common carp (Cyprinus carpio L.)

The NIMA-related kinase 7 (NEK7), a member of the Never in Mitosis Gene A (NIMA) kinase family, participates in the assembly of the NLRP3 inflammasome in mammalian. However, it is currently unclear that the functions of NEK7 in the activation and assembly of NLRP3 inflammasome in teleost. In this research, the cDNA sequence of NEK7 of common carp (CcNEK7) was cloned and its role in the assembly of CcNLRP3 inflammasome was investigated. CcNEK7 was conserved throughout evolution, with its amino acid sequence, three-dimensional structure, and subcellular localization being similar to those in mammals. qPCR detection showed that CcNEK7 had the highest expression levels in the spleen of healthy common carp and could respond to bacteria and virus infection. It was additionally discovered that CcNEK7 can interact with CcNLRP3 and promote the oligomerization of CcNLRP3 and CcASC. Additionally, CcNEK7 significantly increased the CcNLRP3-induced cytotoxicity and pyroptosis, suggesting that CcNEK7 may exerts a regulatory function in the assembly of the CcNLRP3 inflammasome. These results provide a foundation for further understanding the assembly and regulation mechanisms of the inflammasome in bony fish, and also provides a target and theoretical framework for preventing and controlling of various aquatic animal diseases.

Inflammasome Activation and Neutrophil Extracellular Traps in Atherosclerosis

The deposition of cholesterol containing cholesterol crystals and the infiltration of immune cells are features of atherosclerosis. Although the role of cholesterol crystals in the progression of atherosclerosis have long remained unclear, recent studies have clarified the involvement of cholesterol crystals in inflammatory responses. Cholesterol crystals activate the NLRP3 inflammasome, a molecular complex involved in the innate immune system. Activation of NLRP3 inflammasomes in macrophages cause pyroptosis, which is accompanied by the release of inflammatory cytokines such as IL-1β and IL-1α. Furthermore, NLRP3 inflammasome activation drives neutrophil infiltration into atherosclerotic plaques. Cholesterol crystals trigger NETosis against infiltrated neutrophils, a form of cell death characterized by the formation of neutrophil extracellular traps (NETs), which, in turn, prime macrophages to enhance inflammasome-mediated inflammatory responses. Colchicine, an anti-inflammatory drug effective in cardiovascular disease, is expected to inhibit cholesterol crystal-induced NLRP3 inflammasome activation and neutrophil infiltration. In this review, we illustrate the reinforcing cycle of inflammation that is amplified by inflammasome activation and NETosis.

Chemo-sensitive and chemo-resistant ovarian cancer cells show differences in cellular processes leading to pyroptotic cell death

Tumor immunology in ovarian cancer is not completely understood. Chemoresistance limits the success of available treatment options for patients with ovarian cancer. Pyroptosis, pro-inflammatory programmed cell death characterized by membrane pore formation by gasdermin proteins, is important for both immunogenicity and drug resistance. Here, we showed that estrogen increases GSDMC and GSDMD mRNA levels in chemo-sensitive ovarian cancer cells; but, not in chemo-resistant ovarian cancer cells in vitro. GSDMC or GSDMD overexpression increases cell viability in chemo-sensitive ovarian cancer cells; but, not in chemo-resistant ovarian cancer cells. Silencing of GSDMD in chemo-sensitive ovarian cancer cells and silencing of GSDMC in chemo-resistant ovarian cancer cells limit the effect of nigericin, a pyroptosis inducer, on cell viability. Inhibition of caspase-1, -4, -6 or -8 blocks nigericin-induced cell death (pyroptosis) in chemo-sensitive ovarian cancer cells; however, only the inhibition of caspase-1 blocks nigericin-induced cell death in chemo-resistant ovarian cancer cells, showing that caspases participating in pyroptosis might differ between ovarian cancer cells based on their chemo-sensitivity profiles. Treatment with disulfiram, a GSDMD pore formation inhibitor, decreases cell viability in both cell lines. Lastly, we found that in chemo-resistant ovarian cancer cell line, disulfiram and nigericin combination treatment decreases cell viability even more compared to only disulfiram or only nigericin treatment. Combined, our study points that ovarian cancer cells with different chemosensitivity profiles might have certain differences in pyroptotic cell death.

Jiedu Tongluo Tiaogan Formula Modulates Glycolipid Metabolism in Type 2 Diabetes via Pyroptosis: Network Pharmacology and In Vivo Analysis

Type 2 diabetes mellitus (T2DM) is characterized by pancreatic β-cell dysfunction and insulin resistance, with pyroptosis emerging as a key contributor to β-cell loss. Jiedu Tongluo Tiaogan Formula (JTTF), a traditional Chinese medicine (TCM), has shown clinical efficacy in T2DM management, but its mechanism linking pyroptosis remains unexplored. This study integrates UPLC-MS/MS, network pharmacology, and in vivo experiments to elucidate JTTF's anti-diabetic mechanisms. UPLC-MS/MS identified 441 compounds in JTTF, predominantly alkaloids, flavonoids, phenols, and terpenoids. Network pharmacology revealed JTTF's multi-target effects on T2DM-associated pyroptosis, particularly via the NLRP3/Caspase-1/GSDMD pathway. In diabetic mice, JTTF dose-dependently reduced fasting blood glucose, insulin resistance, and dyslipidemia, while restoring pancreatic β-cell morphology. Mechanistically, JTTF suppressed NLRP3 inflammasome activation, downregulated Caspase-1 and GSDMD expression, and attenuated IL-1β/IL-18 release. Notably, this study provides the first evidence of JTTF's anti-pyroptotic effects in T2DM, highlighting its unique ability to modulate glycolipid metabolism and inflammatory cell death concurrently. These findings underscore JTTF's translational promise for preserving β-cell function and suggest future exploration of non-classical pyroptosis pathways. Our work bridges traditional medicine and molecular pharmacology, paving the way for clinical trials and integrative T2DM therapies.

Electroacupuncture Promotes Gastric Motility by Suppressing Pyroptosis via NLRP3/Caspase-1/GSDMD Signaling Pathway in Diabetic Gastroparesis Rats

OBJECTIVE

To investigate the mechanism of electroacupuncture (EA) in treating diabetic gastroparesis (DGP) by inhibiting the activation of Nod-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome and pyroptosis mediated via NLRP3/cysteinyl aspartate specific proteinase-1 (caspase-1)/gasdermin D (GSDMD) signaling pathway.

METHODS

Forty Sprague-Dawley rats were randomly divided into 4 groups including the control, DGP model, EA, and MCC950 groups. The DGP model was established by a one-time high-dose intraperitoneal injection of 2% streptozotocin and a high-glucose and high-fat diet for 8 weeks. EA intervention was conducted at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6) with sparse-dense wave for 15 min, and was administered for 3 courses of 5 days. After intervention, the blood glucose, urine glucose, gastric emptying, and intestinal propulsive rate were observed. Besides, HE staining was used to observe histopathological changes in gastric antrum tissues, and TUNEL staining was utilized to detect DNA damage. Protein expression levels of NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), pro-caspase-1, caspase-1 and GSDMD were measured by Western blot. Immunofluorescence staining was employed to assess the activity of GSDMD-N. Lactate dehydrogenase (LDH) levels were detected by using a biochemical kit.

RESULTS

DGP rats showed persistent hyperglycemia and a significant decrease in gastrointestinal motility (P<0.05 or P<0.01), accompanied by pathological damage in their gastric antrum tissues. Cellular DNA was obviously damaged, and the expressions of NLRP3, ASC, pro-caspase-1, caspase-1 and GSDMD proteins were significantly elevated, along with enhanced fluorescence signals of GSDMD-N and increased LDH release (P<0.01). EA mitigated hyperglycemia, improved gastrointestinal motility in DGP rats and alleviated their pathological injury (P<0.05). Furthermore, EA reduced cellular DNA damage, lowered the protein levels of NLRP3, ASC, pro-caspase-1, caspase-1 and GSDMD, suppressed GSDMD-N activity, and decreased LDH release (P<0.05 or P<0.01), demonstrating effects comparable to MCC950.

CONCLUSION

EA promotes gastrointestinal motility and repairs the pathological damage in DGP rats, and its mechanism may be related to the inhibition of NLRP3 inflammasome and pyroptosis mediated by NLRP3/caspase-1/GSDMD pathway.

Multiwalled carbon nanotubes activate the NLRP3 inflammasome-dependent pyroptosis in macrophages

Macrophages are major innate immune cells for the clearance of inhaled nanoparticles but may undergo cell death upon phagocytosis of certain nanoparticles due to their resistance to lysosomal degradation and high toxicity to the cell. Here we investigated the pyroptotic effect of exposure to fibrogenic multiwalled carbon nanotubes (MWCNTs) on macrophages, an inflammatory form of cell death. We first evaluated MWCNT-induced cell death in M1 and M2 macrophages that mediate the temporal inflammatory response to MWCNTs in mammalian lungs. Macrophages were differentiated from human monocytic THP-1 cells, followed by polarization to M1 or M2 cells. MWCNTs caused concentration- and time-dependent cytotoxicity in M1 and, to a lesser extent, M2 cells. Carbon black, an amorphous carbonous material control for CNTs, did not cause apparent toxicity in the cells. MWCNTs increased the production and secretion of IL-1β, accompanied by activation of caspase-1, in M1, but not M2, cells. Moreover, MWCNTs induced the formation of apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain specks and the release of cathepsin B in M1 cells, revealing activation of the nucleotide-binding, oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome via lysosomal damage. MWCNTs induced the cleavage of gasdermin D (GSDMD) to form the 31 kDa N-terminal fragment (GSDMD-N), the pore-forming peptide causing pyroptotic cell death. Increased IL-1β release was completely suppressed by AC-YVAD-CMK (a caspase-1 inhibitor), MCC-950 (an NLRP3 inflammasome inhibitor), or CA-074 Me (a cathepsin B inhibitor), alongside the blockage of MWCNT-induced cleavage of GSDMD. The study demonstrates that MWCNTs trigger pyroptosis in M1 macrophages and boost sterile inflammation by activating the NLRP3 inflammasome pathway. SIGNIFICANCE STATEMENT: The nucleotide-binding, oligomerization domain-like receptor family pyrin domain containing 3 inflammasome mediates the inflammatory response to fibrogenic nanoparticles in the lung via multiple means. The current study uncovers the induction of pyroptotic death of macrophages as a major means of nanotoxicity and sterile inflammation via the nucleotide-binding, oligomerization domain-like receptor family pyrin domain containing 3 pathway by nanoparticles.

Chaihu Guizhi Ganjiang Decoction ameliorates chronic pancreatitis by modulating the SK1/S1P signaling pathway

Chronic pancreatitis (CP) is a progressive disease characterized by injury on pancreatic acinar cells (PACs), ongoing fibrosis, and gradual loss of exocrine and endocrine functions. Sphingosine kinase 1 (SK1) expression is elevated in injured PACs, and its metabolite sphingosine-1-phosphate (S1P) promotes the activation of pancreatic stellate cell (PSC) through autophagy and pyroptosis. Chaihu Guizhi Ganjiang Decoction (CGGD), a traditional Chinese medicine is widely used in the clinical treatment of digestive diseases. However, whether CCGD affects the SK1/S1P axis and relieves pancreatic damage through this pathway remains unknown. In this study, CP rats were treated with CGGD, individually or in combination with S1P and SKI-178 for four weeks to assess the effect of CGGD on pancreatic injury, fibrosis, autophagy and pyroptosis. The results showed that SK1, S1P and S1PR2 levels were increased in the pancreatic tissues of CP rats, while CGGD reduced these levels. Treatment with S1P exacerbated histological damage, promoted fibrosis, accelerated autophagy, and induced pyroptosis. Conversely, SKI-178 suppressed these effects. Notably, CGGD mitigated histological damage, decreased serum amylase and lipase levels, and alleviated pancreatic fibrosis induced by S1P. Furthermore, CGGD downregulated autophagy and pyroptosis induced by S1P, exhibiting an effect comparable to SKI-178 in CP. In conclusion, CGGD ameliorates pancreatic damage by reducing fibrosis, inhibiting autophagy, and suppressing pyroptosis through the SK1/S1P axis.

Immunologic cell deaths: involvement in the pathogenesis and intervention therapy of periodontitis

Periodontitis is one of the most common diseases and primary causes of tooth loss. The main factor that causes periodontitis is an overactive host immunological response. An in-depth investigation into the molecular pathways that cause periodontitis can aid in creating novel therapeutic approaches for periodontitis and its related systemic disorders. Several immunologic cell death (ICD) pathways have been implicated in advancing periodontitis. Nevertheless, there is still a substantial lack of understanding surrounding the precise molecular mechanisms of ICD in periodontitis. Additionally, the beneficial feature of ICD in periodontitis, which involves its ability to eliminate pathogens, needs further confirmation. According to this, a comprehensive literature search utilizing the Web of Science™, PubMed®, and Scopus® databases was conducted. Only items published in the English language up until October 2024 were taken into account, and finally, 65 relevant papers were selected to be included in this review. In this article, we present a comprehensive analysis of the processes and outcomes of ICD activation in the progression of periodontitis. Lastly, the present difficulties linked to ICDs as a viable treatment option for periodontitis are emphasized.

A bibliometric analysis of the literature published on autophagy, ferroptosis, necroptosis, and pyroptosis in cardiovascular disease from 2009 to 2023

Background

Programmed cell death (PCD) plays a pivotal role in the development and progression of cardiovascular disease (CVD), which remains the leading cause of mortality worldwide. Among the various types of PCD, autophagy, ferroptosis, necroptosis, and pyroptosis have garnered increasing attention due to their involvement in inflammation, oxidative stress, and cardiomyocyte survival. Although numerous studies have explored the underlying mechanisms of these pathways, their therapeutic potential in clinical practice remains limited. With the rapid growth of publications in this field, a comprehensive understanding of research trends and influential studies is essential to guide future investigations. This study aimed to characterize the progress and research hotspots of autophagy in CVD, ferroptosis in CVD, necroptosis in CVD, and pyroptosis in CVD through a bibliometric analysis to provide a comprehensive overview of PCD in CVD.

Methods

Publications from January 1, 2009, to December 31, 2023, were analyzed using the "bibliometrix" R package to assess research output, key contributors, and influential journals in each field.

Results

For the topic of autophagy in CVD, 6,426 articles published by 4,891 institutions from 90 countries/regions were retrieved. For the topic of necroptosis in CVD, 393 articles from 616 organizations in 53 countries/regions were retrieved. For the topic of pyroptosis in CVD, 640 publications from 754 institutions in 48 countries/regions were retrieved. Finally, for the topic of ferroptosis in CVD, 687 articles from 827 institutions in 49 countries/regions were retrieved. Key contributors included Adriana A (22 publications on necroptosis), Ge J, and Ye B (8 publications each on pyroptosis), and Ren J (lead contributor in autophagy and ferroptosis, with 120 and 10 publications, respectively). The most frequently co-cited journals were Cell, Nature, Free Radical Biology and Medicine, and the Journal of Biological Chemistry.

Conclusions

This bibliometric analysis highlights the growing interest in PCD in CVD research, with autophagy and pyroptosis being the central themes. Future studies should examine therapeutic strategies targeting ferroptosis and necroptosis to improve CVD treatment. The findings provide a roadmap for researchers to navigate emerging research hotspots and foster interdisciplinary collaboration.

Gasdermins in pyroptosis, inflammation, and cancer

Pyroptosis is a type of programmed inflammatory cell death characterized by balloon-like swelling, membrane rupture, and the release of inflammatory cytokines and danger signals. Pyroptosis is directly triggered by activated gasdermins (GSDMs) which bind to membrane phospholipids, oligomerize, and form pores in cell membranes. GSDM activation is mediated by various effector proteases via cleavage of the linker region or post-translational modification to release the active N-terminal fragment in response to a variety of pathogenic or intrinsic danger signals. GSDM-mediated pyroptosis is involved in the pathogenesis of an array of infectious and inflammatory diseases and cancers. This review discusses recent advances related to the physiological and pathological functions of GSDM-mediated pyroptosis, as well as therapeutic strategies targeting pyroptosis.

Interplay of ferroptotic and apoptotic cell death and its modulation by BH3-mimetics

Ferroptosis and apoptosis are widely considered to be independent cell death modalities. Ferroptotic cell death is a consequence of insufficient radical detoxification and progressive lipid peroxidation, which is counteracted by glutathione peroxidase-4 (GPX4). Apoptotic cell death can be triggered by a wide variety of stresses, including oxygen radicals, and can be suppressed by anti-apoptotic members of the BCL-2 protein family. Mitochondria are the main interaction site of BCL-2 family members and likewise a major source of oxygen radical stress. We therefore studied if ferroptosis and apoptosis might intersect and possibly interfere with one another. Indeed, cells dying from impaired GPX4 activity displayed hallmarks of both ferroptotic and apoptotic cell death, with the latter including (transient) membrane blebbing, submaximal cytochrome-c release and caspase activation. Targeting BCL-2, MCL-1 or BCL-XL with BH3-mimetics under conditions of moderate ferroptotic stress in many cases synergistically enhanced overall cell death and frequently skewed primarily ferroptotic into apoptotic outcomes. Surprisingly though, in other cases BH3-mimetics, most notably the BCL-XL inhibitor WEHI-539, counter-intuitively suppressed cell death and promoted cell survival following GPX4 inhibition. Further studies revealed that most BH3-mimetics possess previously undescribed antioxidant activities that counteract ferroptotic cell death at commonly employed concentration ranges. Our results therefore show that ferroptosis and apoptosis can intersect. We also show that combining ferroptotic stress with BH3-mimetics, context-dependently can either enhance and convert cell death outcomes between ferroptosis and apoptosis or can also suppress cell death by intrinsic antioxidant activities.

DNA damage in proximal tubules triggers systemic metabolic dysfunction through epigenetically altered macrophages

DNA damage repair is a critical physiological process closely linked to aging. The accumulation of DNA damage in renal proximal tubular epithelial cells (PTEC) is related to a decline in kidney function. Here, we report that DNA double-strand breaks in PTECs lead to systemic metabolic dysfunction, including weight loss, reduced fat mass, impaired glucose tolerance with mitochondrial dysfunction, and increased inflammation in adipose tissues and the liver. Single-cell RNA sequencing analysis reveals expansion of CD11c+ Ccr2+ macrophages in the kidney cortex, liver, and adipose tissues and Ly6Chi monocytes in peripheral blood. DNA damage in PTECs is associated with hypomethylation of macrophage activation genes, including Gasdermin D, in peripheral blood cells, which is linked to reduced DNA methylation at KLF9-binding motifs. Macrophage depletion ameliorates metabolic abnormalities. These findings highlight the impact of kidney DNA damage on systemic metabolic homeostasis, revealing a kidney-blood-metabolism axis mediated by epigenetic changes in macrophages.

The Ways to Die: Cell Death in Liver Pathophysiology

Liver diseases are closely associated with various cell death mechanisms, including apoptosis, necroptosis, autophagy, pyroptosis, and ferroptosis. Each process contributes uniquely to the pathophysiology of liver injury and repair. Importantly, these mechanisms are not limited to hepatocytes; they also significantly involve nonparenchymal cells. This review examines the molecular pathways and regulatory mechanisms underlying these forms of cell death in hepatocytes, emphasizing their roles in several liver diseases, such as ischemia-reperfusion injury, metabolic dysfunction-associated steatotic liver disease, drug-induced liver injury, and alcohol-associated liver disease. Recent insights into ferroptosis and pyroptosis may reveal novel therapeutic targets for managing liver diseases. This review aims to provide a comprehensive overview of these cell death mechanisms in the context of liver diseases, detailing their molecular signaling pathways and implications for potential treatment strategies.

Glutamine limits NLRP3 inflammasome activation and pyroptosis in macrophages by sustaining the IRG1/itaconate axis

Aberrant activation of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome increases the release of mature pro-inflammatory cytokines interleukin (IL)-1β and IL-18, and enhances pyroptosis; thereby necessitating tight regulation of the NLRP3 inflammasome. Dysfunctional glutamine metabolism contributes to the pathogenesis of multiple inflammatory disorders, and the precise mechanism remains to be elucidated. Here, we provide evidence that glutamine deprivation enhances NLRP3 inflammasome activation in macrophages. Indeed, the absence of exogenous glutamine specifically enhanced NLRP3 inflammasome assembly, thereby accelerating pyroptosis and promoting the maturation of IL-1β and IL-18. Inhibition of glutaminolysis exhibited a similar effect to glutamine deprivation, whereas this effect was reversed by α-ketoglutarate (α-KG), a tricarboxylic acid (TCA)-cycle intermediate that can be replenished by glutamine supply. We further observed reduced generation of endogenous itaconate by glutamine deprivation and verified that both exogenous supplementation of itaconate derivative and increased endogenous itaconate production by overexpressing immune-responsive gene 1 [IRG1; also known as aconitate decarboxylase 1 (ACOD1)] could replace glutamine to inhibit the NLRP3 inflammasome. Mechanistically, glutamine deprivation decreased the source of substrate and inhibited transcription factor EB (TFEB)-dependent transcriptional upregulation of IRG1, thereby impairing the IRG1/itaconate axis that suppresses the NLRP3 inflammasome. Furthermore, glutamine deficiency was detected in a murine sepsis model, whereas extrinsic glutamine supplementation conferred protection against intestinal inflammation and tissue damage in septic mice. Taken together, our findings provide a novel insight into the link between glutamine metabolism and NLRP3 inflammasome activation, highlighting the target of glutamine metabolism, which holds as a potential therapeutic strategy for inflammatory diseases.

Cell-Autonomous Immunity: From Cytosolic Sensing to Self-Defense

As an evolutionarily conserved and ubiquitous mechanism of host defense, non-immune cells in vertebrates possess the intrinsic ability to autonomously detect and combat intracellular pathogens. This process, termed cell-autonomous immunity, is distinct from classical innate immunity. In this review, we comprehensively examine the defense mechanisms employed by non-immune cells in response to intracellular pathogen invasion. We provide a detailed analysis of the cytosolic sensors that recognize aberrant nucleic acids, lipopolysaccharide (LPS), and other pathogen-associated molecular patterns (PAMPs). Specifically, we elucidate the molecular mechanisms underlying key signaling pathways, including the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, the retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs)-mitochondrial antiviral signaling (MAVS) axis, and the guanylate-binding proteins (GBPs)-mediated pathway. Furthermore, we critically evaluate the involvement of these pathways in the pathogenesis of various diseases, including autoimmune disorders, inflammatory conditions, and malignancies, while highlighting their potential as therapeutic targets.

Investigation of PANoptosis pathway in age-related macular degeneration triggered by Aβ1-40

Our study aimed to identify PANoptosis in Aβ1-40-induced AMD, both in vivo and in vitro, and to determine if AIM2-PANoptosome mediates this process. We used transcriptomics to explore the signaling pathways and target genes linked to PANoptosis within a mouse model of AMD triggered by Aβ1-40. Optical coherence tomography (OCT), hematoxylin and eosin (H&E) staining, and electroretinography (ERG) were employed to assess retinal damage in terms of morphology and function. Morphological changes in ARPE-19 cells were observed using optical microscopy and scanning electron microscopy. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of cytokines in cell supernatants, mouse orbital serum, and human plasma to evaluate the severity of inflammation. CO-immunoprecipitation(CoIP) and molecular docking were performed to assess the impact and expression of proteins associated with the AIM2-PANoptosome. Quantitative polymerase chain reaction (qPCR), Western blot (WB), immunofluorescence, and apoptosis detection kits were used to evaluate the expression levels of genes and proteins related to PANoptosis-like cell death. Our results showed that the Aβ1-40-induced AMD model had increased expression of apoptosis, necroptosis, and pyroptosis pathways, and AIM2-PANoptosome components. CoIP and docking confirmed increased AIM2, ZBP1, and PYRIN levels under Aβ1-40 treatment. WB and immunofluorescence showed upregulation of PANoptosis-related proteins. Inhibitors reduced Aβ-induced protein expression. ELISA showed increased inflammatory cytokines. Apoptosis assays and microscopy revealed Aβ1-40-induced ARPE-19 cell loss and morphological changes. In conclusion, the Aβ1-40-induced AMD model displayed PANoptosis-like cell death, offering insights into disease pathogenesis.

The Regulatory Role of NcRNAs in Pyroptosis and Disease Pathogenesis

Non-coding RNAs (ncRNAs), as critical regulators of gene expression, play a pivotal role in the modulation of pyroptosis and exhibit a close association with a wide range of diseases. Pyroptosis is a form of programmed cell death mediated by inflammasomes, characterized by cell membrane perforation, release of inflammatory cytokines, and a robust immune response. Recent studies have revealed that ncRNAs influence the initiation and execution of pyroptosis by regulating the expression of pyroptosis-related genes or modulating associated signaling pathways. This review systematically summarizes the molecular mechanisms and applications of ncRNAs in diseases such as cancer, infectious diseases, neurological disorders, cardiovascular diseases, and metabolic disorders. It further explores the potential of ncRNAs as diagnostic biomarkers and therapeutic targets, elucidates the intricate interactions among ncRNAs, pyroptosis, and diseases, and provides novel strategies and directions for the precision treatment of related diseases.

NLRP3 inflammasome as a therapeutic target in doxorubicin-induced cardiotoxicity: role of phytochemicals

Doxorubicin (DOX) has received widespread attention as a broad-spectrum antitumor drug. However, it has been a recognized challenge that long-term DOX injections can lead to severe cardiotoxicity. There are numerous interventions to DOX-induced cardiotoxicity, and the most cost-effective is phytochemicals. It has been reported that phytochemicals have complex and diverse biological properties, facilitating the mitigation of DOX-induced cardiotoxicity. DOX-induced cardiotoxicity has numerous pathological mechanisms, and the nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome-mediated cardiomyocyte pyroptosis is one of them. This review initially presents an overview of the pathological mechanisms that underlie cardiotoxicity induced by DOX. Subsequently, we present a comprehensive elucidation of the structure and activation of the NLRP3 inflammasome. Finally, we provide a detailed summary of phytochemicals that can mitigate DOX-induced cardiotoxicity by influencing the expression of the NLRP3 inflammasome in cardiomyocytes.

Cell Death Mechanisms in Mycobacterium abscessus Infection: A Double-Edged Sword

Infections caused by non-tuberculous mycobacteria (NTM), such as Mycobacterium abscessus, elicit diverse cell death mechanisms including apoptosis, necrosis, and pyroptosis, which play key roles in immunopathogenesis. NTM can manipulate these cell death pathways to evade host immune responses, ensuring their intracellular survival and persistence. Apoptosis may aid in antigen presentation and immune activation, while necrosis and pyroptosis trigger excessive inflammation, leading to tissue damage. Autophagy, a crucial cellular defense mechanism, is often induced in response to NTM infection; however, M. abscessus has evolved mechanisms to inhibit autophagic processes, enhancing its ability to survive within host cells. This manipulation of cell death pathways, particularly the dysregulation of autophagy and ferroptosis, contributes to chronic infection, immune evasion, and tissue damage, complicating disease management. Understanding these mechanisms offers potential therapeutic targets for improving treatment strategies against M. abscessus infections.

CircTHADA regulates endothelial cell pyroptosis in diabetic retinopathy through miR-494-3p/CASP1/GSDMD-N/IL-1β pathway

Our study aimed to elucidate the mechanism by which circTHADA competitively adsorbs miR-494-3p to regulate CASP1-mediated endothelial cell (EC) pyroptosis in diabetic retinopathy (DR). To be specific, we used high glucose (HG)-induced human retinal microvascular endothelial cells (HRMECs) as DR cell models and streptozotocin (STZ)-treated mice as DR mouse models. The expression levels of circTHADA, miR-494-3p, CASP1, NLRP3, GSDMD-N and IL-1β were detected and flow cytrometry was applied to measure cell pyroptosis rate and dual luciferase reporter assays were utilized to determine the direct binding sites. As a result, exacerbated EC pyroptosis in DR was detected in DR cell and mouse models. Based on differentially expressed circRNA profiles by microarray and experimental verification, circTHADA was filtered and identified to regulate CASP1-mediated EC pyroptosis. miR-494-3p was then proven to be involved in circTHADA-mediated ceRNA network by bioinformatics analysis and experimental verification. Further gain- and loss-of-function experiments and rescue experiments revealed the function of the circTHADA/miR-494-3p/CASP1 axis in pyroptosis.

LPS-induced extracellular AREG triggers macrophage pyroptosis through the EGFR/TLR4 signaling pathway

Amphiregulin (AREG), a member of the EGF family, exists as a transmembrane protein anchored to the cell surface. In response to external stimuli, its extracellular domain is released into the extracellular matrix through paracrine or autocrine signaling. However, its role in septic macrophage pyroptosis remains poorly understood. This study aims to investigate the role of extracellular AREG in septic macrophages, mice, and patients. We found that high expression of extracellular AREG was regulated by RPLP1 at the translation level, which increased the expression of IL-6, CCL2, and CCL3 protein, as well as Caspase 1, IL-1β, and Nlrp3 mRNA expression, resulting in macrophage pyroptosis. Mechanistically, macrophage pyroptosis was aggravated by extracellular AREG pretreatment, which was triggered by extracellular AREG and ATP (adenosine 5'-triphosphate). The AREG-neutralizing antibody reduced LPS-induced epidermal growth factor receptor (EGFR) activation, TLR4 expression, and pyroptosis. Extracellular AREG-induced macrophage pyroptosis decreased with EGFR and NF-κB inhibition, as well as TLR4 and Myd88 knockout. Additionally, DTT-pretreated extracellular AREG suppressed macrophage pyroptosis. In vivo, extracellular AREG attenuates systemic inflammation infiltration and delays survival in a septic mouse model. Furthermore, extracellular AREG mediates sepsis in humans, and genes involved in the AREG-mediated pyroptosis signaling pathway were highly expressed in patients with severe sepsis compared with those with general or moderate sepsis. Overall, LPS-induced extracellular AREG aggravated or triggered macrophage pyroptosis through the EGFR/TLR4/Myd88/NF-κB signaling pathway, providing promising treatment strategies for sepsis.

Manipulation of cancer cell pyroptosis for therapeutic approaches: challenges and opportunities

Remarkable advances have been achieved following discoveries that gasdermins are the executioners of pyroptosis. The pyroptotic process consists a subcellular permeabilization phase and a cell lysis phase, the latter of which is irreversible. Besides immune cells, pyroptosis has also been observed in cancer cells, which exhibit distinct mechanisms compared to canonical immune cell pyroptosis. Although chronic cancer cell pyroptosis fuels tumor growth, intense pyroptotic cell death in tumor cells enhances anticancer immunity by promoting killer lymphocytes infiltration. Triggering pyroptosis in cancer cells is emerging as a promising strategy for cancer treatment. In this review, we introduce the process of cancer cell pyroptosis and its role in antitumor immunity, discuss the translation of these insights into therapies, and highlight current challenges and opportunities in the investigation of cancer cell pyroptosis.