Gasdermin E suppresses tumour growth by activating anti-tumour immunity

Improving the efficacy of cancer immunotherapy by host-defence caerin 1.1 and 1.9 peptides

Cancer remains a major global health challenge. Immunotherapy has revolutionized the management of cancer, yet only a limited number of patients respond to such treatments. This is largely attributed to the immunosuppressive tumor microenvironment, which diminishes the effectiveness of immunotherapy. Recent studies have underscored the potential of naturally derived caerin 1 peptides, particularly caerin 1.1 and caerin 1.9, which exhibit strong antitumor effects and enhance the efficacy of immunotherapies in animal models. This review encapsulates the current research aimed at augmenting the effectiveness of immunotherapy, focusing on the role of caerin 1.1 and caerin 1.9 in boosting immunotherapeutic outcomes, elucidating possible mechanisms, and discussing their limitations and challenges.

Applications of pyroptosis activators in tumor immunotherapy

Contemporary progress in tumor immunotherapy has solidified its role as an effective approach in combating cancer. Nonetheless, the prevalent "immune cold" state within the tumor microenvironment poses a substantial barrier to its efficacy. Addressing this, pyroptosis-a gasdermin-mediated programmed cell death characterized by its inflammatory profile-emerges as a crucial mechanism. It catalyzes the release of vast quantities of pro-inflammatory cytokines and immunogens, potentially transforming immunosuppressive "cold" tumors into reactive "hot" ones. Herein, we will initially present an overview of pyroptosis as a distinct form of cell death, along with its molecular mechanisms. Subsequently, we will focus on introducing how pyroptosis activators are utilized in the field of tumor immunotherapy. Insights gained from applications of pyroptosis activators in tumor immunotherapy could lead to the development of safe and efficient pyroptosis activators, significantly enriching the arsenal for tumor immunotherapy.

The role of extracellular vesicles in pyroptosis-mediated infectious and non-infectious diseases

Pyroptosis, a lytic and pro-inflammatory cell death, is important in various pathophysiological processes. Host- and bacteria-derived extracellular vesicles (EVs), as natural nanocarriers messengers, are versatile mediators of intercellular communication between different types of cells. Recently, emerging research has suggested that EVs exhibit multifaceted roles in disease progression by manipulating pyroptosis. This review focuses on new findings concerning how EVs shape disease progression in infectious and non-infectious diseases by regulating pyroptosis. Understanding the characteristics and activity of EVs-mediated pyroptotic death may conducive to the discovery of novel mechanisms and more efficient therapeutic targets in infectious and non-infectious diseases.

Biological function and potential application of PANoptosis-related genes in colorectal carcinogenesis

PANoptosis induces programmed cell death (PCD) through extensive crosstalk and is associated with development of cancer. However, the functional mechanisms, clinical significance, and potential applications of PANoptosis-related genes (PRGs) in colorectal cancer (CRC) have not been fully elucidated. Functional enrichment of key PRGs was analyzed based on databases, and relationships between key PRGs and the immune microenvironment, immune cell infiltration, chemotherapy drug sensitivity, tumor progression genes, single-cell cellular subgroups, signal transduction pathways, transcription factor regulation, and miRNA regulatory networks were systematically explored. This study identified 5 key PRGs associated with CRC: BCL10, CDKN2A, DAPK1, PYGM and TIMP1. Then, RT-PCR was used to verify expression of these genes in CRC cells and tissues. Clinical significance and prognostic value of key genes were further verified by multiple datasets. Analyses of the immune microenvironment, immune cell infiltration, chemotherapy drug sensitivity, tumor progression genes, single-cell cellular subgroups, and signal transduction pathways suggest a close relationship between these key genes and development of CRC. In addition, a novel prognostic nomogram model for CRC was successfully constructed by combining important clinical indicators and the key genes. In conclusion, our findings offer new insights for understanding the pathogenesis of CRC, predicting CRC prognosis, and identifying multiple therapeutic targets for future CRC therapy.

Euphohelioscopin A enhances NK cell antitumor immunity through GSDME-triggered pyroptosis

Immune evasion by cancer cells poses a significant challenge for natural killer cell-based immunotherapy. Pyroptosis, a newly discovered form of programmed cell death, has shown great potential for enhancing the antitumor immunity of natural killer cells. Consequently, targeting pyroptosis has become an attractive strategy for boosting natural killer cell activity against cancer. In this study, various assays were conducted, including natural killer cell cytotoxicity assays, flow cytometry, xenograft tumor models, real-time polymerase chain reaction, and enzyme-linked immunosorbent assay, to assess natural killer cell-mediated cell killing, as well as gene and protein expressions. The results indicated that euphohelioscopin A, a potential pyroptosis activator, enhances natural killer cell-mediated lysis of tumor cells, resulting in inhibiting tumor growth that could be reversed by natural killer cell depletion. Furthermore, we found that euphohelioscopin A significantly enhanced IFNγ production in natural killer cells and synergistically upregulated GSDME with IFNγ in cancer cells. Euphohelioscopin A also increased the cleavage of GSDME, promoting granzyme B-induced pyroptosis, which could be reversed by GSDME knockdown and IFNγ blockade. Overall, the findings suggested that euphohelioscopin A enhanced natural killer cell-mediated killing of cancer cells by triggering pyroptosis, making euphohelioscopin A a promising pyroptosis activator with great potential for use in natural killer cell-based cancer immunotherapy.

Pyroptosis, gasdermins and allergic diseases

Pyroptosis is an inflammatory form of programmed cell death that is distinct from necrosis and apoptosis. Pyroptosis is primarily mediated by the gasdermin family of proteins (GSDMA-E and PVJK), which, when activated by proteolytic cleavage, form pores in the plasma membrane, leading to cell death. While much of the past research on pyroptosis has focused on its role in cancer, metabolic disorders, and infectious diseases, recent experimental and observational studies have begun to implicate pyroptosis in allergic diseases. These studies suggest that gasdermin-mediated pyroptosis contributes to the development of allergic conditions and could offer novel targets for therapy. Here, we review our current understanding of pyroptosis with an emphasis on the role of gasdermins as executioners of pyroptosis and potential mediators to allergic disease. We highlight new discoveries that establish a mechanistic link between the biochemical actions of gasdermins and the onset of allergic diseases. Additionally, we discuss how pyroptosis and gasdermins might contribute to the dysfunction of epithelial barrier, a key factor believed to initiate the progression of various allergic diseases.

HDAC inhibitor regulates the tumor immune microenvironment via pyroptosis in triple negative breast cancer

Pyroptosis, an inflammatory form of cell death, promotes the release of immunogenic substances and stimulates immune cell recruitment, a process, which could turn cold tumors into hot ones. Thus, instigating pyroptosis in triple-negative breast cancer (TNBC) serves as a viable method for restoring antitumor immunity. We analyzed the effects of Histone Deacetylase Inhibitors (HDACi) on TNBC cells using the Cell Counting Kit-8 and colony formation assay. Apoptosis and lactate dehydrogenase (LDH) release assays were utilized to determine the form of cell death. The pyroptotic executor was validated by quantitative real-time polymerase chain reaction and western blot. Transcriptome was analyzed to investigate pyroptosis-inducing mechanisms. A subcutaneously transplanted tumor model was generated in BALB/c mice to evaluate infiltration of immune cells. HDACi significantly diminished cell proliferation, and pyroptotic "balloon"-like cells became apparent. HDACi led to an intra and extracellular material exchange, signified by the release of LDH and the uptake of propidium iodide. Among the gasdermin family, TNBC cells expressed maximum quantities of GSDME, and expression of GSDMA, GSDMB, and GSDME were augmented post HDACi treatment. Pyroptosis was instigated via the activation of the caspase 3-GSDME pathway with the potential mechanisms being cell cycle arrest and altered intracellular REDOX balance due to aberrant glutathione metabolism. In vivo experiments demonstrated that HDACi can activate pyroptosis, limit tumor growth, and escalate CD8+ lymphocyte and CD11b+ cell infiltration along with an increased presence of granzyme B in tumors. HDACi can instigate pyroptosis in TNBC, promoting infiltration of immune cells and consequently intensifying the efficacy of anticancer immunity.

AI-powered omics-based drug pair discovery for pyroptosis therapy targeting triple-negative breast cancer

Due to low success rates and long cycles of traditional drug development, the clinical tendency is to apply omics techniques to reveal patient-level disease characteristics and individualized responses to treatment. However, the heterogeneous form of data and uneven distribution of targets make drug discovery and precision medicine a non-trivial task. This study takes pyroptosis therapy for triple-negative breast cancer (TNBC) as a paradigm and uses data mining of a large TNBC cohort and drug databases to establish a biofactor-regulated neural network for rapidly screening and optimizing compound pyroptosis drug pairs. Subsequently, biomimetic nanococrystals are prepared using the preferred combination of mitoxantrone and gambogic acid for rational drug delivery. The unique mechanism of obtained nanococrystals regulating pyroptosis genes through ribosomal stress and triggering pyroptosis cascade immune effects are revealed in TNBC models. In this work, a target omics-based intelligent compound drug discovery framework explores an innovative drug development paradigm, which repurposes existing drugs and enables precise treatment of refractory diseases.

Overview of pyroptosis mechanism and in-depth analysis of cardiomyocyte pyroptosis mediated by NF-κB pathway in heart failure

The pyroptosis of cardiomyocytes has become an essential topic in heart failure research. The abnormal accumulation of these biological factors, including angiotensin II, advanced glycation end products, and various growth factors (such as connective tissue growth factor, vascular endothelial growth factor, transforming growth factor beta, among others), activates the nuclear factor-κB (NF-κB) signaling pathway in cardiovascular diseases, ultimately leading to pyroptosis of cardiomyocytes. Therefore, exploring the underlying molecular biological mechanisms is essential for developing novel drugs and therapeutic strategies. However, our current understanding of the precise regulatory mechanism of this complex signaling pathway in cardiomyocyte pyroptosis is still limited. Given this, this study reviews the milestone discoveries in the field of pyroptosis research since 1986, analyzes in detail the similarities, differences, and interactions between pyroptosis and other cell death modes (such as apoptosis, necroptosis, autophagy, and ferroptosis), and explores the deep connection between pyroptosis and heart failure. At the same time, it depicts in detail the complete pathway of the activation, transmission, and eventual cardiomyocyte pyroptosis of the NF-κB signaling pathway in the process of heart failure. In addition, the study also systematically summarizes various therapeutic approaches that can inhibit NF-κB to reduce cardiomyocyte pyroptosis, including drugs, natural compounds, small molecule inhibitors, gene editing, and other cutting-edge technologies, aiming to provide solid scientific support and new research perspectives for the prevention and treatment of heart failure.

Receptor-interacting protein kinase 1 confers autophagic promotion of gasdermin E-mediated pyroptosis in aristolochic acid-induced acute kidney injury

Aristolochic acid (AA) exposure is a severe public health concern worldwide. AAs damage the kidney with an inevitable acute phase that is similar to acute kidney injury (AKI). Gasdermin E (GSDME) is abundant in the kidney; thus; it-mediated pyroptosis might be essential in connecting cell death and inflammation and promoting AAs-AKI. However, the role and exact mechanism of pyroptosis in AAs-AKI have not been investigated. In this study, aristolochic acid I (AAI) was used to establish AKI models. The expression and translocation results showed GSDME-mediated pyroptosis in AAI-AKI. Knocking down GSDME attenuated AAI-induced cell death and transcription of proinflammatory cytokines. Mechanistic research inhibiting caspase (casp) 3, casp 8, and casp 9 with specific chemical antagonists demonstrated that GSDME was activated by cleaved casp 3. Furthermore, the kinase activity of upstream receptor-interacting protein kinase 1 (RIPK1) was significantly elevated, and inhibiting RIPK1 with specific inhibitors markedly improved AAI-induced cell damage. In addition, the level of autophagy was obviously increased. Pretreatment with a specific autophagic inhibitor (3-methyladenine) or knockdown of autophagic genes (Atg5 or Atg7) evidently reduced the activity of RIPK1 and downstream apoptosis and pyroptosis, thus attenuating AA-induced cell injury, which suggested that RIPK1 was a novel link conferring autophagic promotion of pyroptosis. These findings reveal GSDME-mediated pyroptosis for the first time in AAI-induced AKI, propose its novel role in the transcription of cytokines, and demonstrate that autophagy promotes pyroptosis via the RIPK1-dependent apoptotic pathway. This study promotes the understanding of the toxic effects and exact mechanisms of AAs. This will contribute to evaluating the environmental risk of AA exposure and might provide potential therapeutic targets for AA-AKI.

Gasdermins as evolutionarily conserved executors of inflammation and cell death

The gasdermins are a family of pore-forming proteins that have recently emerged as executors of pyroptosis, a lytic form of cell death that is induced by the innate immune system to eradicate infected or malignant cells. Mammalian gasdermins comprise a cytotoxic N-terminal domain, a flexible linker and a C-terminal repressor domain. Proteolytic cleavage in the linker releases the cytotoxic domain, thereby allowing it to form β-barrel membrane pores. Formation of gasdermin pores in the plasma membrane eventually leads to a loss of the electrochemical gradient, cell death and membrane rupture. Here we review recent work that has expanded our understanding of gasdermin biology and function in mammals by revealing their activation mechanism, their regulation and their roles in autoimmunity, host defence and cancer. We further highlight fungal and bacterial gasdermin pore formation pointing to a conserved mechanism of cell death induction.

Nanoparticle-mediated cell pyroptosis: a new therapeutic strategy for inflammatory diseases and cancer

Pyroptosis, a lytic form of cell death mediated by the gasdermin family, is characterized by cell swelling and membrane rupture. Inducing pyroptosis in cancer cells can enhance antitumor immune responses and is a promising strategy for cancer therapy. However, excessive pyroptosis may trigger the development of inflammatory diseases due to immoderate and continuous inflammatory reactions. Nanomaterials and nanobiotechnology, renowned for their unique advantages and diverse structures, have garnered increasing attention owing to their potential to induce pyroptosis in diseases such as cancer. A nano-delivery system for drug-induced pyroptosis in cancer cells can overcome the limitations of small molecules. Furthermore, nanomedicines can directly induce and manipulate pyroptosis. This review summarizes and discusses the latest advancements in nanoparticle-based treatments with pyroptosis among inflammatory diseases and cancer, focusing on their functions and mechanisms and providing valuable insights into selecting nanodrugs for pyroptosis. However, the clinical application of these strategies still faces challenges owing to a limited understanding of nanobiological interactions. Finally, future perspectives on the emerging field of pyroptotic nanomaterials are presented.

Tumor editing suppresses innate and adaptive antitumor immunity and is reversed by inhibiting DNA methylation

Cancer cells edit gene expression to evade immunosurveillance. However, genome-wide studies of gene editing during early tumorigenesis are lacking. Here we used single-cell RNA sequencing in a breast cancer genetically engineered mouse model (GEMM) to identify edited genes without bias. Late tumors repressed antitumor immunity genes, reducing infiltrating immune cells and tumor-immune cell communications. Innate immune genes, especially interferon-stimulated genes, dominated the list of downregulated tumor genes, while genes that regulate cell-intrinsic malignancy were mostly unedited. Naive and activated CD8+ T cells in early tumors were replaced with exhausted or precursor-exhausted cells in late tumors. Repression of immune genes was reversed by inhibiting DNA methylation using low-dose decitabine, which suppressed tumor growth and restored immune control, increasing the number, functionality and memory of tumor-infiltrating lymphocytes and reducing the number of myeloid suppressor cells. Decitabine induced important interferon, pyroptosis and necroptosis genes, inflammatory cell death and immune control in GEMM and implanted breast and melanoma tumors.

Icaritin Exerts Anti-Cancer Effects through Modulating Pyroptosis and Immune Activities in Hepatocellular Carcinoma

Icaritin (ICT), a natural compound extracted from the dried leaves of the genus Epimedium, possesses antitumor and immunomodulatory properties. However, the mechanisms through which ICT modulates pyroptosis and immune response in hepatocellular carcinoma (HCC) remain unclear. This study demonstrated that ICT exhibits pyroptosis-inducing and anti-hepatocarcinoma effects. Specifically, the caspase1-GSDMD and caspase3-GSDME pathways were found to be involved in ICT-triggered pyroptosis. Furthermore, ICT promoted pyroptosis in co-cultivation of HepG2 cells and macrophages, regulating the release of inflammatory cytokines and the transformation of macrophages into a proinflammatory phenotype. In the Hepa1-6+Luc liver cancer model, ICT treatment significantly increased the expression of cleaved-caspase1, cleaved-caspase3, and granzyme B, modulated cytokine secretion, and stimulated CD8+ T cell infiltration, resulting in a reduction in tumor growth. In conclusion, the findings in this research suggested that ICT may modulate cell pyroptosis in HCC and subsequently regulate the immune microenvironment of the tumor. These observations may expand the understanding of the pharmacological mechanism of ICT, as well as the therapy of liver cancer.

Pyroptosis in Skeleton Diseases: A Potential Therapeutic Target Based on Inflammatory Cell Death

Skeletal disorders, including fractures, osteoporosis, osteoarthritis, rheumatoid arthritis, and spinal degenerative conditions, along with associated spinal cord injuries, significantly impair daily life and impose a substantial burden. Many of these conditions are notably linked to inflammation, with some classified as inflammatory diseases. Pyroptosis, a newly recognized form of inflammatory cell death, is primarily triggered by inflammasomes and executed by caspases, leading to inflammation and cell death through gasdermin proteins. Emerging research underscores the pivotal role of pyroptosis in skeletal disorders. This review explores the pyroptosis signaling pathways and their involvement in skeletal diseases, the modulation of pyroptosis by other signals in these conditions, and the current evidence supporting the therapeutic potential of targeting pyroptosis in treating skeletal disorders, aiming to offer novel insights for their management.

Raptinal: a powerful tool for rapid induction of apoptotic cell death

Chemical inducers of apoptosis have been utilized for decades as tools to uncover steps of the apoptotic cascade and to treat various diseases, most notably cancer. While there are several useful compounds available, limitations in potency, universality, or speed of cell death of these pro-apoptotic agents have meant that no single compound is suitable for all (or most) purposes. Raptinal is a recently described small molecule that induces intrinsic pathway apoptosis rapidly and reliably, and consequently, has been utilized in cell culture and whole organisms for a wide range of biological studies. Its distinct mechanism of action complements the current arsenal of cytotoxic compounds, making it useful as a probe for the apoptosis pathway and other cellular processes. The rapid induction of cell death by Raptinal and its widespread commercial availability make it the pro-apoptotic agent of choice for many applications.

GSDMD is associated with survival in human breast cancer but does not impact anti-tumor immunity in a mouse breast cancer model

Inflammation plays a pivotal role in cancer development, with chronic inflammation promoting tumor progression and treatment resistance, whereas acute inflammatory responses contribute to protective anti-tumor immunity. Gasdermin D (GSDMD) mediates the release of pro-inflammatory cytokines such as IL-1β. While the release of IL-1β is directly linked to the progression of several types of cancers, the role of GSDMD in cancer is less clear. In this study, we show that GSDMD expression is upregulated in human breast, kidney, liver, and prostate cancer. Higher GSDMD expression correlated with increased survival in primary breast invasive carcinoma (BRCA), but not in liver hepatocellular carcinoma (LIHC). In BRCA, but not in LIHC, high GSDMD expression correlated with a myeloid cell signature associated with improved prognosis. To further investigate the role of GSDMD in anticancer immunity, we induced breast cancer and hepatoma tumors in GSDMD-deficient mice. Contrary to our expectations, GSDMD deficiency had no effect on tumor growth, immune cell infiltration, or cytokine expression in the tumor microenvironment, except for Cxcl10 upregulation in hepatoma tumors. In vitro and in vivo innate immune activation with TLR ligands, that prime inflammatory responses, revealed no significant difference between GSDMD-deficient and wild-type mice. These results suggest that the impact of GSDMD on anticancer immunity is dependent on the tumor type. They underscore the complex role of inflammatory pathways in cancer, emphasizing the need for further exploration into the multifaceted effects of GSDMD in various tumor microenvironments. As several pharmacological modulators of GSDMD are available, this may lead to novel strategies for combination therapy in cancer.

Biodegradable Persistent Luminescence Nanoparticles as Pyroptosis Inducer for High-Efficiency Tumor Immunotherapy

Pyroptosis possesses potent antitumor immune activity, making pyroptosis inducer development a promising direction for tumor immunotherapy. Persistent luminescence nanoparticles (PLNPs) are highly sensitive optical probes extensively employed in tumor diagnosis and therapy. However, a pyroptosis inducer based on PLNPs has not been reported yet. Herein, polyethylene glycol-poly lactic acid-co-glycolic acid (PEG-PLGA: PP) modified biodegradable CaS:Eu2+ (CSE@PP) PLNPs are synthesized as a pyroptosis inducer for tumor immunotherapy for the first time. The synthesized CSE@PP possesses biowindow persistent luminescence (PersL) and pH-responsive degradation properties, allowing it to remain stable under neutral pH but degrade when exposed to weak acid (pH < 6.5). During degradation within the tumor, CSE@PP constantly releases H2S and Ca2+ while its PersL gradually fades away. Thus, the PersL signal can self-monitor H2S and Ca2+ release. Furthermore, the released H2S and Ca2+ result in mitochondrial dysfunction and the inactivation of reactive oxygen species scavenging enzymes, synergistic facilitating intracellular oxidative stress, which induces caspase-1/GSDM-D dependent pyroptosis and subsequent antitumor immune responses. In a word, it is confirmed that CSE@PP can self-monitor H2S and Ca2+ release and pyroptosis-mediated tumor Immunotherapy. This work will facilitate biomedical applications of PLNPs and inspire pyroptosis-induced tumor immunotherapy.

USP11 promotes renal tubular cell pyroptosis and fibrosis in UUO mice via inhibiting KLF4 ubiquitin degradation

The pyroptosis of renal tubular epithelial cells leads to tubular loss and inflammation and then promotes renal fibrosis. The transcription factor Krüppel-like factor 4 (KLF4) can bidirectionally regulate the transcription of target genes. Our previous study revealed that sustained elevation of KLF4 is responsible for the transition of acute kidney injury (AKI) into chronic kidney disease (CKD) and renal fibrosis. In this study, we explored the upstream mechanisms of renal tubular epithelial cell pyroptosis from the perspective of posttranslational regulation and focused on the transcription factor KLF4. Mice were subjected to unilateral ureteral obstruction (UUO) surgery and euthanized on D7 or D14 for renal tissue harvesting. We showed that the pyroptosis of renal tubular epithelial cells mediated by both the Caspase-1/GSDMD and Caspase-3/GSDME pathways was time-dependently increased in UUO mouse kidneys. Furthermore, we found that the expression of the transcription factor KLF4 was also upregulated in a time-dependent manner in UUO mouse kidneys. Tubular epithelial cell-specific Klf4 knockout alleviated UUO-induced pyroptosis and renal fibrosis. In Ang II-treated mouse renal proximal tubular epithelial cells (MTECs), we demonstrated that KLF4 bound to the promoter regions of Caspase-3 and Caspase-1 and directly increased their transcription. In addition, we found that ubiquitin-specific protease 11 (USP11) was increased in UUO mouse kidneys. USP11 deubiquitinated KLF4. Knockout of Usp11 or pretreatment with the USP11 inhibitor mitoxantrone (3 mg/kg, i.p., twice a week for two weeks before UUO surgery) significantly alleviated the increases in KLF4 expression, pyroptosis and renal fibrosis. These results demonstrated that the increased expression of USP11 in renal tubular cells prevents the ubiquitin degradation of KLF4 and that elevated KLF4 promotes inflammation and renal fibrosis by initiating tubular cell pyroptosis.

Photocatalytic Carbon Dots-Triggered Pyroptosis for Whole Cancer Cell Vaccines

Manufacturing whole cancer cell vaccines (WCCV) with both biosafety and efficacy is crucial for tumor immunotherapy. Pyroptotic cancer cells, due to their highly immunogenic properties, present a promising avenue for the development of WCCV. However, the successful development of WCCV based on pyroptotic cancer cells is yet to be accomplished. Here, a facile strategy that utilized photocatalytic carbon dots (CDs) to induce pyroptosis of cancer cells for fabricating WCCV is reported. Photocatalytic CDs are capable of generating substantial amounts of hydroxyl radicals and can effectively decrease cytoplasmic pH values under white light irradiation. This process efficiently triggers cancer cell pyroptosis through the reactive oxygen species (ROS)-mitochondria-caspase 3-gasdermin E pathway and the proton motive force-driven mitochondrial ATP synthesis pathway. Moreover, in vitro, these photocatalytic CDs-induced pyroptotic cancer cells (PCIP) can hyperactivate macrophage (M0-M1) with upregulation of major histocompatibility complex class II expression. In vivo, PCIP induced specific immune-preventive effects in melanoma and breast cancer mouse models through anticancer immune memory, demonstrating effective WCCV. This work provides novel insights for inducing cancer cell pyroptosis and bridges the gap in the fabrication of WCCV based on pyroptotic cancer cells.

Pyroptosis and the fight against lung cancer

Pyroptosis, a newly characterized type of inflammatory programmed cell death (PCD), is usually triggered by multiple inflammasomes which can recognize different danger or damage-associated molecular patterns (DAMPs), leading to the activation of caspase-1 and the cleavage of gasdermin D (GSDMD). Gasdermin family pore-forming proteins are the executers of pyroptosis and are normally maintained in an inactive state through auto-inhibition. Upon caspases mediated cleavage of gasdermins, the pro-pyroptotic N-terminal fragment is released from the auto-inhibition of C-terminal fragment and oligomerizes, forming pores in the plasma membrane. This results in the secretion of interleukin (IL)-1β, IL-18, and high-mobility group box 1 (HMGB1), generating osmotic swelling and lysis. Current therapeutic approaches including chemotherapy, radiotherapy, molecularly targeted therapy and immunotherapy for lung cancer treatment efficiently force the cancer cells to undergo pyroptosis, which then generates local and systemic antitumor immunity. Thus, pyroptosis is recognized as a new therapeutic regimen for the treatment of lung cancer. In this review, we briefly describe the signaling pathways involved in pyroptosis, and endeavor to discuss the antitumor effects of pyroptosis and its potential application in lung cancer therapy, focusing on the contribution of pyroptosis to microenvironmental reprogramming and evocation of antitumor immune response.

Comprehensive analysis, diagnosis, prognosis, and cordycepin (CD) regulations for GSDME expressions in pan-cancers

The Gasdermin E gene (GSDME) plays roles in deafness and cancers. However, the roles and mechanisms in cancers are complex, and the same gene exhibits different mechanisms and actions in different types of cancers. Online databases, such as GEPIA2, cBioPortal, and DNMIVD, were used to comprehensively analyze GSDME profiles, DNA methylations, mutations, diagnosis, and prognosis in patients with tumor tissues and matched healthy tissues. Western blotting and RT-PCR were used to monitor the regulation of GSDME by Cordycepin (CD) in cancer cell lines. We revealed that GSDME expression is significantly upregulated in eight cancers (ACC, DLBC, GBM, HNSC, LGG, PAAD, SKCM, and THYM) and significantly downregulated in seven cancers (COAD, KICH, LAML, OV, READ, UCES, and UCS). The overall survival was longer only in ACC, but shorter in four cancers, including COAD, KIRC, LIHC, and STAD, when GSDME was highly expressed in cancers compared with the corresponding normal tissues. Moreover, the high expression of GSDME was negatively correlated with the poor prognosis of ACC, while the low expression of GSDME was negatively correlated with the poor prognosis of COAD, suggesting that GSDME might serve as a good prognostic factor in these two cancer types. Accordingly, results indicated that the DNA methylations of those 7 CpG sites constitute a potentially effective signature to distinguish different tumors from adjacent healthy tissues. Gene mutations for GSDME were frequently observed in a variety of tumors, with UCES having the highest frequency. Moreover, CD treatment inhibited GSDME expression in different cancer cell lines, while overexpression of GSDME promoted cell migration and invasion. Thus, we have systematically and successfully clarified the GSDME expression profiles, diagnostic values, and prognostic values in pan-cancers. Targeting GSDME with CD implies therapeutic significance and a mechanism for antitumor roles in some types of cancers via increasing the sensitivity of chemotherapy. Altogether, our study may provide a strategy and biomarker for clinical diagnosis, prognostics, and treatment of cancers by targeting GSDME.

Gasdermin-E-mediated pyroptosis drives immune checkpoint inhibitor-associated myocarditis via cGAS-STING activation

Immune checkpoint inhibitor (ICI)-induced myocarditis involves intensive immune/inflammation activation; however, its molecular basis is unclear. Here, we show that gasdermin-E (GSDME), a gasdermin family member, drives ICI-induced myocarditis. Pyroptosis mediated by GSDME, but not the canonical GSDMD, is activated in myocardial tissue of mice and cancer patients with ICI-induced myocarditis. Deficiency of GSDME in male mice alleviates ICI-induced cardiac infiltration of T cells, macrophages, and monocytes, as well as mitochondrial damage and inflammation. Restoration of GSDME expression specifically in cardiomyocytes, rather than myeloid cells, in GSDME-deficient mice reproduces ICI-induced myocarditis. Mechanistically, quantitative proteomics reveal that GSDME-dependent pyroptosis promotes cell death and mitochondrial DNA release, which in turn activates cGAS-STING signaling, triggering a robust interferon response and myocardial immune/inflammation activation. Pharmacological blockade of GSDME attenuates ICI-induced myocarditis and improves long-term survival in mice. Our findings may advance the understanding of ICI-induced myocarditis and suggest that targeting the GSDME-cGAS-STING-interferon axis may help prevent and manage ICI-associated myocarditis.

An artificial metabzyme for tumour-cell-specific metabolic therapy

Metabolic dysregulation constitutes a pivotal feature of cancer progression. Enzymes with multiple metal active sites play a major role in this process. Here we report the first metabolic-enzyme-like FeMoO4 nanocatalyst, dubbed 'artificial metabzyme'. It showcases dual active centres, namely, Fe2+ and tetrahedral Mo4+, that mirror the characteristic architecture of the archetypal metabolic enzyme xanthine oxidoreductase. Employing spatially dynamic metabolomics in conjunction with the assessments of tumour-associated metabolites, we demonstrate that FeMoO4 metabzyme catalyses the metabolic conversion of tumour-abundant xanthine into uric acid. Subsequent metabolic adjustments orchestrate crosstalk with immune cells, suggesting a potential therapeutic pathway for cancer. Our study introduces an innovative paradigm in cancer therapy, where tumour cells are metabolically reprogrammed to autonomously modulate and directly interface with immune cells through the intervention of an artificial metabzyme, for tumour-cell-specific metabolic therapy.

Unveiling the hidden dangers: a review of non-apoptotic programmed cell death in anesthetic-induced developmental neurotoxicity

Anesthetic-induced developmental neurotoxicity (AIDN) can arise due to various factors, among which aberrant nerve cell death is a prominent risk factor. Animal studies have reported that repeated or prolonged anesthetic exposure can cause significant neuroapoptosis in the developing brain. Lately, non-apoptotic programmed cell deaths (PCDs), characterized by inflammation and oxidative stress, have gained increasing attention. Substantial evidence suggests that non-apoptotic PCDs are essential for neuronal cell death in AIDN compared to apoptosis. This article examines relevant publications in the PubMed database until April 2024. Only original articles in English that investigated the potential manifestations of non-apoptotic PCD in AIDN were analysed. Specifically, it investigates necroptosis, pyroptosis, ferroptosis, and parthanatos, elucidating the signaling mechanisms associated with each form. Furthermore, this study explores the potential relevance of these non-apoptotic PCDs pathways to the pathological mechanisms underlying AIDN, drawing upon their distinctive characteristics. Despite the considerable challenges involved in translating fundamental scientific knowledge into clinical therapeutic interventions, this comprehensive review offers a theoretical foundation for developing innovative preventive and treatment strategies targeting non-apoptotic PCDs in the context of AIDN.

Inhibiting caspase-3/GSDME-mediated pyroptosis ameliorates septic lung injury in mice model

Acute lung injury is one of the most serious complications of sepsis, which is a common critical illness in clinic. This study aims to investigate the role of caspase-3/ gasdermin-E (GSDME)-mediated pyroptosis in sepsis-induced lung injury in mice model. Cecal ligation (CLP) operation was used to establish mice sepsis-induced lung injury model. Lung coefficient, hematoxylin and eosin staining and transmission electron microscopy were used to observe the lung injury degree. In addition, caspase-3-specific inhibitor Z-DEVD-FMK and GSDME-derived inhibitor AC-DMLD-CMK were used in CLP model, caspase-3 activity, GSDME immunofluorescence, serum lactate dehydrogenase (LDH) and interleukin-6 (IL-6) levels, TUNEL staining, and the expression levels of GSDME related proteins were detected. The mice in CLP group showed the increased expressions of cleaved-caspase-3 and GSDME-N terminal, destruction of lung structure, and the increases of LDH, IL-6, IL-18 and IL-1β levels, which were improved in mice treated with Z-DEVD-FMK or AC-DMLD-CMK. In conclusion, caspase-3/GSDME mediated pyroptosis is involved in the occurrence of sepsis-induced lung injury in mice model, inhibiting caspase-3 or GSDME can both alleviate lung injury.

Insight into the structure, function and the tumor suppression effect of gasdermin E

Gasdermin E (GSDME), which is also known as DFNA5, was first identified as a deafness-related gene that is expressed in cochlear hair cells, and mutation of this gene causes autosomal dominant neurogenic hearing loss. Later studies revealed that GSDME is mostly expressed in the kidney, placenta, muscle and brain cells, but it is expressed at low levels in tumor cells. The GSDME gene encodes the GSDME protein, which is a member of the gasdermin (GSDM) family and has been shown to participate in the induction of apoptosis and pyroptosis. The current literature suggests that Caspase-3 and Granzyme B (Gzm B) can cleave GSDME to generate the active N-terminal fragment (GSDME-NT), which integrates with the cell membrane and forms pores in this membrane to induce pyroptosis. Furthermore, GSDME also forms pores in mitochondrial membranes to release apoptosis factors, such as cytochrome c (Cyt c) and high-temperature requirement protein A2 (HtrA2/Omi), and subsequently activates the intrinsic apoptosis pathway. In recent years, GSDME has been shown to exert tumor-suppressive effects, suggesting that it has potential therapeutic effects on tumors. In this review, we introduce the structure and function of GSDME and the mechanism by which it induces cell death, and we discuss its tumor suppressive effect.

Copper Homeostasis Based on Cuproptosis-Related Signature Optimizes Molecular Subtyping and Treatment of Glioma

Copper is essential in living organisms and crucial to various physiological processes. Normal physiological conditions are in a state of copper homeostasis to ensure normal biochemical and metabolic processes. Dysregulation of copper homeostasis has been associated with multiple diseases, especially cancer. Cuproptosis is a copper-dependent cell death mediated by excess copper or homeostasis dysregulation. Elesclomol is a common inducer of cuproptosis, carrying copper into the cell and producing excess copper. Cuproptosis modulates tumor proliferation-related signaling pathways and is closely associated with remodeling the tumor microenvironment. In gliomas, the role of cuproptosis and copper homeostasis needs to be better characterized. This study systematically analyzed cuproptosis-related genes (CRGs) and constructed a cuproptosis signature for gliomas. The signature closely links the subtypes and clinical features of glioma patients. The results showed a greater tendency toward dysregulation of copper homeostasis as the malignant grade of glioma patients increased. In addition, CRGs-signature effectively predicted the sensitivity of glioma cells to elesclomol and verified that elesclomol inhibited glioma mainly through inducing cellular cuproptosis. In summary, we found different copper homeostatic features in gliomas and verified the anticancer mechanism of elesclomol, which provides a theoretical basis for developing novel therapeutic strategies for gliomas.

Targeting novel regulated cell death: Ferroptosis, pyroptosis and necroptosis in anti-PD-1/PD-L1 cancer immunotherapy

Chemotherapy, radiotherapy, and immunotherapy represent key tumour treatment strategies. Notably, immune checkpoint inhibitors (ICIs), particularly anti-programmed cell death 1 (PD1) and anti-programmed cell death ligand 1 (PD-L1), have shown clinical efficacy in clinical tumour immunotherapy. However, the limited effectiveness of ICIs is evident due to many cancers exhibiting poor responses to this treatment. An emerging avenue involves triggering non-apoptotic regulated cell death (RCD), a significant mechanism driving cancer cell death in diverse cancer treatments. Recent research demonstrates that combining RCD inducers with ICIs significantly enhances their antitumor efficacy across various cancer types. The use of anti-PD-1/PD-L1 immunotherapy activates CD8+ T cells, prompting the initiation of novel RCD forms, such as ferroptosis, pyroptosis, and necroptosis. However, the functions and mechanisms of non-apoptotic RCD in anti-PD1/PD-L1 therapy remain insufficiently explored. This review summarises the emerging roles of ferroptosis, pyroptosis, and necroptosis in anti-PD1/PD-L1 immunotherapy. It emphasises the synergy between nanomaterials and PD-1/PD-L1 inhibitors to induce non-apoptotic RCD in different cancer types. Furthermore, targeting cell death signalling pathways in combination with anti-PD1/PD-L1 therapies holds promise as a prospective immunotherapy strategy for tumour treatment.

Targeting ROS in cancer: rationale and strategies

Reactive oxygen species (ROS) in biological systems are transient but essential molecules that are generated and eliminated by a complex set of delicately balanced molecular machineries. Disruption of redox homeostasis has been associated with various human diseases, especially cancer, in which increased ROS levels are thought to have a major role in tumour development and progression. As such, modulation of cellular redox status by targeting ROS and their regulatory machineries is considered a promising therapeutic strategy for cancer treatment. Recently, there has been major progress in this field, including the discovery of novel redox signalling pathways that affect the metabolism of tumour cells as well as immune cells in the tumour microenvironment, and the intriguing ROS regulation of biomolecular phase separation. Progress has also been made in exploring redox regulation in cancer stem cells, the role of ROS in determining cell fate and new anticancer agents that target ROS. This Review discusses these research developments and their implications for cancer therapy and drug discovery, as well as emerging concepts, paradoxes and future perspectives.

Enhanced pyroptosis induction with pore-forming gene delivery for osteosarcoma microenvironment reshaping

Osteosarcoma is the most common malignant bone tumor without efficient management for improving 5-year event-free survival. Immunotherapy is also limited due to its highly immunosuppressive tumor microenvironment (TME). Pore-forming gasdermins (GSDMs)-mediated pyroptosis has gained increasing concern in reshaping TME, however, the expressions and relationships of GSDMs with osteosarcoma remain unclear. Herein, gasdermin E (GSDME) expression is found to be positively correlated with the prognosis and immune infiltration of osteosarcoma patients, and low GSDME expression was observed. A vector termed as LPAD contains abundant hydroxyl groups for hydrating layer formation was then prepared to deliver the GSDME gene to upregulate protein expression in osteosarcoma for efficient TME reshaping via enhanced pyroptosis induction. Atomistic molecular dynamics simulations analysis proved that the hydroxyl groups increased LPAD hydration abilities by enhancing coulombic interaction. The upregulated GSDME expression together with cleaved caspase-3 provided impressive pyroptosis induction. The pyroptosis further initiated proinflammatory cytokines release, increased immune cell infiltration, activated adaptive immune responses and create a favorable immunogenic hot TME. The study not only confirms the role of GSDME in the immune infiltration and prognosis of osteosarcoma, but also provides a promising strategy for the inhibition of osteosarcoma by pore-forming GSDME gene delivery induced enhanced pyroptosis to reshape the TME of osteosarcoma.

Gain-of-function variants in GSDME cause pyroptosis and apoptosis associated with post-lingual hearing loss

Gasdermin E (GSDME), a member of the gasdermin protein family, is associated with post-lingual hearing loss. All GSDME pathogenic mutations lead to skipping exon 8; however, the molecular mechanisms underlying hearing loss caused by GSDME mutants remain unclear. GSDME was recently identified as one of the mediators of programmed cell death, including apoptosis and pyroptosis. Therefore, in this study, we injected mice with GSDME mutant (MT) and examined the expression levels to assess its effect on hearing impairment. We observed loss of hair cells in the organ of Corti and spiral ganglion neurons. Further, the N-terminal release from the GSDME mutant in HEI-OC1 cells caused pyroptosis, characterized by cell swelling and rupture of the plasma membrane, releasing lactate dehydrogenase and cytokines such as interleukin-1β. We also observed that the N-terminal release from GSDME mutants could permeabilize the mitochondrial membrane, releasing cytochromes and activating the mitochondrial apoptotic pathway, thereby generating possible positive feedback on the cleavage of GSDME. Furthermore, we found that treatment with disulfiram or dimethyl fumarate might inhibit pyroptosis and apoptosis by inhibiting the release of GSDME-N from GSDME mutants. In conclusion, this study elucidated the molecular mechanism associated with hearing loss caused by GSDME gene mutations, offering novel insights for potential treatment strategies.

GSDMD and GSDME synergy in the transition of acute kidney injury to chronic kidney disease

BACKGROUND AND HYPOTHESIS

Acute kidney injury (AKI) could progress to chronic kidney disease (CKD) and the AKI-CKD transition has major clinical significance. A growing body of evidence has unveiled the role of pyroptosis in kidney injury. We postulate that GSDMD and GSDME exert cumulative effects on the AKI-CKD transition by modulating different cellular responses.

METHODS

We established an AKI-CKD transition model induced by folic acid in wildtype (WT), Gsdmd-/-, Gsdme-/-, and Gsdmd-/-Gsdme-/- mice. Tubular injury, renal fibrosis and inflammatory responses were evaluated. In vitro studies were conducted to investigate the interplay among tubular cells, neutrophils, and macrophages.

RESULTS

Double deletion of Gsdmd and Gsdme conferred heightened protection against AKI, mitigating inflammatory responses, including the formation of neutrophil extracellular traps (NETs), macrophage polarization and differentiation, and ultimately renal fibrosis, compared with wildtype mice and mice with single deletion of either Gsdmd or Gsdme. Gsdme, but not Gsdmd deficiency, shielded tubular cells from pyroptosis. GSDME-dependent tubular cell death stimulated NETs formation and prompted macrophage polarization towards a pro-inflammatory phenotype. Gsdmd deficiency suppressed NETs formation and subsequently hindered NETs-induced macrophage-to-myofibroblast transition (MMT).

CONCLUSION

GSDMD and GSDME collaborate to contribute to AKI and subsequent renal fibrosis induced by folic acid. Synchronous inhibition of GSDMD and GSDME could be an innovative therapeutic strategy for mitigating the AKI-CKD transition.

Let's make it personal: CRISPR tools in manipulating cell death pathways for cancer treatment

Advancements in the CRISPR technology, a game-changer in experimental research, have revolutionized various fields of life sciences and more profoundly, cancer research. Cell death pathways are among the most deregulated in cancer cells and are considered as critical aspects in cancer development. Through decades, our knowledge of the mechanisms orchestrating programmed cellular death has increased substantially, attributed to the revolution of cutting-edge technologies. The heroic appearance of CRISPR systems have expanded the available screening platform and genome engineering toolbox to detect mutations and create precise genome edits. In that context, the precise ability of this system for identification and targeting of mutations in cell death signaling pathways that result in cancer development and therapy resistance is an auspicious choice to transform and accelerate the individualized cancer therapy. The concept of personalized cancer therapy stands on the identification of molecular characterization of the individual tumor and its microenvironment in order to provide a precise treatment with the highest possible outcome and minimum toxicity. This study explored the potential of CRISPR technology in precision cancer treatment by identifying and targeting specific cell death pathways. It showed the promise of CRISPR in finding key components and mutations involved in programmed cell death, making it a potential tool for targeted cancer therapy. However, this study also highlighted the challenges and limitations that need to be addressed in future research to fully realize the potential of CRISPR in cancer treatment.

Release of IL-1β and IL-18 in human primary bronchial epithelial cells exposed to cigarette smoke is independent of NLRP3

Cigarette smoke (CS) is a major risk factor for chronic lung diseases and promotes activation of pattern recognition receptors in the bronchial epithelium. NOD-like receptor family, pyrin domain-containing 3 (NLRP3) is a pattern recognition receptor whose activation leads to caspase-1 cleavage, maturation/release of IL-1β and IL-18, and eventually pyroptosis. Whether the NLRP3 inflammasome participates in CS-induced inflammation in bronchial epithelial cells is still unclear. Herein, we evaluated the involvement of NLRP3 in CS-induced inflammatory responses in human primary bronchial epithelial cells. To this purpose, human primary bronchial epithelial cells were stimulated with CS extracts (CSE) and lytic cell death, caspase activation (-1, -8, -3/7), cytokine release (IL-1β, IL-18, and IL-8), NLRP3, pro-IL-1β/pro-IL-18 mRNA, and protein expression were measured. The impact of inhibitors of NLRP3 (MCC950), caspases, and the effect of the antioxidant N-acetyl cysteine were evaluated. We found that CSE increased pro-IL-1β expression and induced activation of caspase-1 and release of IL-1β and IL-18. These events were independent of NLRP3 and we found that NLRP3 was not expressed. N-acetyl cysteine reverted CSE-induced caspase-1 activation. Overall, our findings support that the bronchial epithelium may play a central role in the release of IL-1 family cytokines independently of NLRP3 in the lungs of smokers.

Mitoxantrone Combined with Engineered TRAIL-Nanovesicles for Enhanced Cancer Immunotherapy Via Converting Apoptosis into Pyroptosis

Pyroptosis, a highly inflammatory form of programmed cell death, has emerged as a promising target for cancer immunotherapy. However, in the context of pyroptosis execution, while both caspase-3 and GSDME are essential, it is noteworthy that GSDME is frequently under-expressed in cold tumors. To overcome this limitation, engineered cellular nanovesicles (NVs) presenting TRAIL on their membranes (NVTRAIL) are developed to trigger the upregulation of cleaved caspase-3. When strategically combined with the chemotherapeutic agent mitoxantrone (MTO), known for its ability to enhance GSDME expression, MTO@NVTRAIL can convert cancer cells from apoptosis into pyroptosis, inhibit the tumor growth and metastasis successfully in primary tumor. The microparticles released by pyroptotic tumor cells also exhibited certain cytotoxicity against other tumor cells. In addition, tumor cells exposed to the combination treatment of MTO@NVTRAIL in vitro have also demonstrated potential utility as a novel form of vaccine for cancer immunotherapy. Flow analysis of the tumor microenvironment and draining lymph nodes reveals an increased proportion of matured dendritic cells and activation of T cells. In summary, the research provided a reference and alternative approach to induce cancer pyroptosis for clinical antitumor therapy based on engineered cellular nanovesicles and chemotherapy.

Dual-Responsive Epigenetic Inhibitor Nanoprodrug Combined with Oncolytic Virus Synergistically Boost Cancer Immunotherapy by Igniting Gasdermin E-Mediated Pyroptosis

Cancer immunotherapy has emerged as a promising approach for the treatment of various cancers. However, the immunosuppressive tumor microenvironment (TME) limits the efficacy of current immunotherapies. In this study, we designed a dual-responsive DNA methyltransferase inhibitor nanoprodrug ACNPs for combination therapy with oncolytic herpes simplex virus (oHSV). We found that the epigenetic inhibitor 5-Azacytidine (5-Aza) upregulated gasdermin E (GSDME) expression at the gene level, whereas the oHSV decreased the ubiquitination and degradation of GSDME to elevate its levels. Based on these observations, we further discovered that ACNPs and oHSV synergistically enhanced GSDME-mediated pyroptosis. Additionally, the combination therapy of ACNPs and oHSV effectively inhibited tumor growth, remodeled the immunosuppressive TME, and improved the efficacy of immune checkpoint blockade (ICB) therapy. These results demonstrate the potential to overcome immunosuppression through synergistic combinations, offering a promising approach for cancer immunotherapy.

The Role and Therapeutic Potential of Pyroptosis in Colorectal Cancer: A Review

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. The unlimited proliferation of tumor cells is one of the key features resulting in the malignant development and progression of CRC. Consequently, understanding the potential proliferation and growth molecular mechanisms and developing effective therapeutic strategies have become key in CRC treatment. Pyroptosis is an emerging type of regulated cell death (RCD) that has a significant role in cells proliferation and growth. For the last few years, numerous studies have indicated a close correlation between pyroptosis and the occurrence, progression, and treatment of many malignancies, including CRC. The development of effective therapeutic strategies to inhibit tumor growth and proliferation has become a key area in CRC treatment. Thus, this review mainly summarized the different pyroptosis pathways and mechanisms, the anti-tumor (tumor suppressor) and protective roles of pyroptosis in CRC, and the clinical and prognostic value of pyroptosis in CRC, which may contribute to exploring new therapeutic strategies for CRC.

[Research Progress on the Role of GSDME-mediated Pyroptosis in the Treatment of Lung Cancer]

Lung cancer causes a significant threat to human health. Despite considerable advancements in the treatment technologies in recent years, the five-year survival rate for lung cancer patients remains low. In this context, the discovery of pyroptosis, a unique cell death mechanism, offers a novel perspective for exploring new pathways of lung cancer treatment. Particularly, the role of gasdermin E (GSDME) in the process of pyroptosis reveals its tremendous potential in lung cancer therapy. Recent studies have made considerable progress in understanding the role of GSDME-mediated pyroptosis in lung cancer growth, the lung cancer microenvironment, and the effect of GSDME methylation on lung cancer treatment. This paper summarizes these research advancements and analyzes the potential and possible side effects of GSDME-mediated pyroptosis in lung cancer therapy, aiming to provide a theoretical foundation for developing more effective strategies for lung cancer treatment.
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Inflammatory caspase substrate specificities

Caspases are a family of cysteine proteases that act as molecular scissors to cleave substrates and regulate biological processes such as programmed cell death and inflammation. Extensive efforts have been made to identify caspase substrates and to determine factors that dictate substrate specificity. Thousands of putative substrates have been identified for caspases that regulate an immunologically silent type of cell death known as apoptosis, but less is known about substrates of the inflammatory caspases that regulate an immunostimulatory type of cell death called pyroptosis. Furthermore, much of our understanding of caspase substrate specificities is derived from work done with peptide substrates, which do not often translate to native protein substrates. Our knowledge of inflammatory caspase biology and substrates has recently expanded and here, we discuss the recent advances in our understanding of caspase substrate specificities, with a focus on inflammatory caspases. We highlight new substrates that have been discovered and discuss the factors that engender specificity. Recent evidence suggests that inflammatory caspases likely utilize two binding interfaces to recognize and process substrates, the active site and a conserved exosite.

Fluorinated Titanium Oxide (TiO2-xFx) Nanospindles as Ultrasound-Triggered Pyroptosis Inducers to Boost Sonodynamic Immunotherapy

Pyroptosis is an inflammatory form of programmed cell death associated with the immune system that can be induced by reactive oxygen species (ROS). As a therapeutic strategy with better penetration depth, sonodynamic therapy (SDT) is expected to induce pyroptosis of cancer cells and boost the immune response. However, it is still a limited problem to precisely adjust the structure of sonosensitizers to exhibit satisfactory sono-catalytic properties. Herein, fluorinated titanium oxide (TiO2-xFx) sonosensitizers were developed to induce pyroptosis under ultrasound (US) to boost antitumor immune responses, enabling highly effective SDT. On the one hand, the introduction of F atoms significantly reduced the adsorption energy of TiO2-xFx for oxygen and water, which is conducive to the occurrence of sono-catalytic reactions. On the other hand, the process of F replacing O increased the oxygen vacancies of the sonosensitizer and shortened the band gap, which enabled powerful ROS generation ability under US stimulation. In this case, large amounts of ROS could effectively kill cancer cells by inducing mitochondrial damage and disrupting oxidative homeostasis, leading to significant cell pyroptosis. Moreover, SDT treatment with TiO2-xFx not only suppressed tumor proliferation but also elicited robust immune memory effects and hindered tumor recurrence. This work highlighted the importance of precisely regulating the structure of sonosensitizers to achieve efficient ROS generation for inducing pyroptosis, which sets the stage for the further development of SDT-immunotherapy.

The crosstalk between immune cells and tumor pyroptosis: advancing cancer immunotherapy strategies

Pyroptosis is a cell death process characterized by cell swelling until membrane rupture and release of intracellular contents. As an effective tumor treatment strategy, inducing tumor cell pyroptosis has received widespread attention. In this process, the immune components within the tumor microenvironment play a key regulatory role. By regulating and altering the functions of immune cells such as cytotoxic T lymphocytes, natural killer cells, tumor-associated macrophages, and neutrophils, tumor cell pyroptosis can be induced. This article provides a comprehensive review of the molecular mechanisms of cell pyroptosis, the impact of the tumor immune microenvironment on tumor cell pyroptosis, and its mechanisms. It aims to gain an in-depth understanding of the communication between the tumor immune microenvironment and tumor cells, and to provide theoretical support for the development of new tumor immunotherapies.

Ligustrazine alleviates the progression of coronary artery calcification by inhibiting caspase-3/GSDME mediated pyroptosis

Coronary artery calcification (CAC) is an early marker for atherosclerosis and is mainly induced by the osteoblast-like phenotype conversion of vascular smooth muscle cells (VSMCs). Recent reports indicate that NOD-like receptor protein 3 (NLRP3)-mediated pyroptosis plays a significant role in the calcification of vascular smooth muscle cells (VSMCs), making it a promising target for treating calcific aortic valve disease (CAC). Ligustrazine, or tetramethylpyrazine (TMP), has been found effective in various cardiovascular and cerebrovascular diseases and is suggested to inhibit NLRP3-mediated pyroptosis. However, the function of TMP in CAC is unknown. Herein, influences of TMP on β-glycerophosphate (β-GP)-stimulated VSMCs and OPG-/- mice were explored. Mouse Aortic Vascular Smooth Muscle (MOVAS-1) cells were stimulated by β-GP with si- caspase-3, si- Gasdermin E (GSDME) or TMP. Increased calcification, reactive oxygen species (ROS) level, Interleukin-1beta (IL-1β) and Interleukin-18 (IL-18) levels, lactate dehydrogenase (LDH) release, enhanced apoptosis, and activated cysteine-aspartic acid protease-3 (caspase-3)/GSDME signaling were observed in β-GP-stimulated MOVAS-1 cells, which was sharply alleviated by si-caspase-3, si-GSDME or TMP. Furthermore, the impact of TMP on the β-GP-induced calcification and injury in MOVAS-1 cells was abolished by raptinal, an activator of caspase-3. Subsequently, OPG-/- mice were dosed with TMP or TMP combined with raptinal. Calcium deposition, increased nodules, elevated IL-1β and IL-18 levels, upregulated CASP3 and actin alpha 2, smooth muscle (ACTA2), and activated caspase-3/GSDME signaling in OPG-/- mice were markedly alleviated by TMP, which were notably reversed by the co-administration of raptinal. Collectively, TMP mitigated CAC by inhibiting caspase-3/GSDME mediated pyroptosis.

Mitochondrial Quality Control Processes at the Crossroads of Cell Death and Survival: Mechanisms and Signaling Pathways

Biological aging results from an accumulation of damage in the face of reduced resilience. One major driver of aging is cell senescence, a state in which cells remain viable but lose their proliferative capacity, undergo metabolic alterations, and become resistant to apoptosis. This is accompanied by complex cellular changes that enable the development of a senescence-associated secretory phenotype (SASP). Mitochondria, organelles involved in energy provision and activities essential for regulating cell survival and death, are negatively impacted by aging. The age-associated decline in mitochondrial function is also accompanied by the development of chronic low-grade sterile inflammation. The latter shares some features and mediators with the SASP. Indeed, the unloading of damage-associated molecular patterns (DAMPs) at the extracellular level can trigger sterile inflammatory responses and mitochondria can contribute to the generation of DAMPs with pro-inflammatory properties. The extrusion of mitochondrial DNA (mtDNA) via mitochondrial outer membrane permeabilization under an apoptotic stress triggers senescence programs. Additional pathways can contribute to sterile inflammation. For instance, pyroptosis is a caspase-dependent inducer of systemic inflammation, which is also elicited by mtDNA release and contributes to aging. Herein, we overview the molecular mechanisms that may link mitochondrial dyshomeostasis, pyroptosis, sterile inflammation, and senescence and discuss how these contribute to aging and could be exploited as molecular targets for alleviating the cell damage burden and achieving healthy longevity.

Granzyme B-activated IL18 potentiates αβ and γδ CAR T cell immunotherapy in a tumor-dependent manner

Interleukin (IL)18 is a potent pro-inflammatory cytokine that is activated upon caspase 1 cleavage of the latent precursor, pro-IL18. Therapeutic T cell armoring with IL18 promotes autocrine stimulation and positive modulation of the tumor microenvironment (TME). However, existing strategies are imperfect since they involve constitutive/poorly regulated activity or fail to modify the TME. Here, we have substituted the caspase 1 cleavage site within pro-IL18 with that preferred by granzyme B, yielding GzB-IL18. We demonstrate that GzB-IL18 is constitutively released but remains functionally latent unless chimeric antigen receptor (CAR) T cells are activated, owing to concomitant granzyme B release. Armoring with GzB-IL18 enhances cytolytic activity, proliferation, interferon (IFN)-γ release, and anti-tumor efficacy by a similar magnitude to constitutively active IL18. We also demonstrate that GzB-IL18 provides a highly effective armoring strategy for γδ CAR T cells, leading to enhanced metabolic fitness and significant potentiation of therapeutic activity. Finally, we show that constitutively active IL18 can unmask CAR T cell-mediated cytokine release syndrome in immunocompetent mice. By contrast, GzB-IL18 promotes anti-tumor activity and myeloid cell re-programming without inducing such toxicity. Using this stringent system, we have tightly coupled the biological activity of IL18 to the activation state of the host CAR T cell, favoring safer clinical implementation of this technology.

Pyroptosis-related long-noncoding RNA signature predicting survival and immunotherapy efficacy in patients with lung squamous cell carcinoma

Pyroptosis-related long-noncoding RNAs (PRlncRNAs) play an important role in cancer progression. However, their role in lung squamous cell carcinoma (LUSC) is unclear. A risk model was constructed using the least absolute shrinkage and selection operator (LASSO) Cox regression analysis based on RNA sequencing data from The Cancer Genome Atlas database. The LUSC cohort was divided into high- and low-risk groups based on the median risk score. For the prognostic value of the model, the Kaplan-Meier analysis, log-rank test, and Cox regression analysis were performed. A nomogram was constructed to predict the prognosis of patients, using a risk score and clinical parameters such as age, sex, clinical stage, and tumor node metastasis classification (TNM) stage. Afterwards, six common algorithms were employed to assess the invasion of immune cells. The Gene Set Enrichment Analysis (GSEA) was conducted to identify differences between patients at high and low risk. Furthermore, the pRRophetic package was employed to forecast the half-maximal inhibitory doses of prevalent chemotherapeutic drugs, while the tumor immune dysfunction and exclusion score was computed to anticipate the response to immunotherapy. The expression levels of the seven PRlncRNAs were examined in both LUSC and normal lung epithelial cell lines using RT-qPCR. Proliferation, migration, and invasion assays were also carried out to investigate the role of MIR193BHG in LUSC cells. Patients in the low-risk group showed prolonged survival in the total cohort or subgroup analysis. The Cox regression analysis showed that the risk model could act as an independent prognostic factor for patients with LUSC. The results of GSEA analysis revealed that the high-risk group showed enrichment of cytokine pathways, Janus tyrosine kinase/signal transducer and activator of the transcription signalling pathway, and Toll-like receptor pathway. Conversely, the low-risk group showed enrichment of several gene repair pathways. Furthermore, the risk score was positively correlated with immune cell infiltration. Moreover, patients in the high-risk category showed reduced responsiveness to conventional chemotherapeutic medications and immunotherapy. The majority of the long noncoding RNAs in the risk model were confirmed to be overexpressed in LUSC cell lines compared to normal lung epithelial cell lines by in vitro tests. Further studies have shown that downregulating the expression of MIR193BHG may inhibit the growth, movement, and infiltration capabilities of LUSC cells, whereas increasing the expression of MIR193BHG could enhance these malignant tendencies. This study found that PRlncRNAs were linked to the prognosis of LUSC patients. The risk model, evaluated across various clinical parameters and treatment modalities, shows potential as a future reference for clinical applications.

GSDME-mediated pyroptosis promotes anti-tumor immunity of neoadjuvant chemotherapy in breast cancer

Paclitaxel and anthracycline-based chemotherapy is one of the standard treatment options for breast cancer. However, only about 6-30% of breast cancer patients achieved a pathological complete response (pCR), and the mechanism responsible for the difference is still unclear. In this study, random forest algorithm was used to screen feature genes, and artificial neural network (ANN) algorithm was used to construct an ANN model for predicting the efficacy of neoadjuvant chemotherapy for breast cancer. Furthermore, digital pathology, cytology, and molecular biology experiments were used to verify the relationship between the efficacy of neoadjuvant chemotherapy and immune ecology. It was found that paclitaxel and doxorubicin, an anthracycline, could induce typical pyroptosis and bubbling in breast cancer cells, accompanied by gasdermin E (GSDME) cleavage. Paclitaxel with LDH release and Annexin V/PI doubule positive cell populations, and accompanied by the increased release of damage-associated molecular patterns, HMGB1 and ATP. Cell coculture experiments also demonstrated enhanced phagocytosis of macrophages and increased the levels of IFN-γ and IL-2 secretion after paclitaxel treatment. Mechanistically, GSDME may mediate paclitaxel and doxorubicin-induced pyroptosis in breast cancer cells through the caspase-9/caspase-3 pathway, activate anti-tumor immunity, and promote the efficacy of paclitaxel and anthracycline-based neoadjuvant chemotherapy. This study has practical guiding significance for the precision treatment of breast cancer, and can also provide ideas for understanding molecular mechanisms related to the chemotherapy sensitivity.

The role of pyroptosis in metabolism and metabolic disease

Pyroptosis is a lytic and pro-inflammatory form of regulated cell death characterized by the formation of membrane pores mediated by the gasdermin protein family. Two main activation pathways have been documented: the caspase-1-dependent canonical pathway and the caspase-4/5/11-dependent noncanonical pathway. Pyroptosis leads to cell swelling, lysis, and the subsequent release of inflammatory mediators, including interleukin-1β (IL-1β) and interleukin-18 (IL-18). Chronic inflammation is a well-established foundation and driver for the development of metabolic diseases. Conversely, metabolic pathway dysregulation can also induce cellular pyroptosis. Recent studies have highlighted the significant role of pyroptosis modulation in various metabolic diseases, including type 2 diabetes mellitus, obesity, and metabolic (dysfunction) associated fatty liver disease. These findings suggest that pyroptosis may serve as a promising novel therapeutic target for metabolic diseases. This paper reviews an in-depth study of the current advancements in understanding the role of pyroptosis in the progression of metabolic diseases.

Exploring the Oncogenic Potential of TIMM8A: A Crucial Factor in Breast Cancer Tumorigenesis

BACKGROUND

Female breast cancer has become the world's most common malignant tumor, displacing lung malignancy, and the incidence of malignant tumors has increased continuously in recent decades. However, the underlying molecular mechanisms of breast tumorigenesis have not been fully elucidated. By consulting the literature, we discovered that the TIMM8A gene could affect oxidative stress and apoptosis in patients with Mohr-Tranebjærg syndrome. However, the biological function of TIMM8A has yet to be explored.

MATERIALS AND METHODS

We investigated the expression level of TIMM8A via bioinformatic analysis and performed immunohistochemistry, diagnostic value, immune infiltration, functional enrichment, and survival analyses. Nonetheless, in vitro, additional experiments were performed. We explored whether TIMM8A expression was greater in breast tumors than in nearby normal tissues through qRT‒PCR. The expression of TIMM8A was knocked down by siRNA. Then, we conducted proliferation tests (CCK-8 experiment and colony formation) and Transwell assays (migration and invasion assays) to determine the specific biological functions of TIMM8A in the MDA-MB-231 and BT-549 cell lines.

RESULTS

Tumor samples exhibited higher TIMM8A expression and exon expression, whereas normal tissues had higher TIMM8A methylation. The expression level of TIMM8A was linked to immune infiltration and survival, making it a valuable prognostic indicator and effective diagnostic tool. Functional enrichment analysis of TIMM8A indicated potential pathways through which it may play a role. In vitro experiments demonstrated that suppressing TIMM8A significantly inhibited the viability, colony formation, migration, and invasion of breast carcinoma cell lines.

CONCLUSION

This study revealed that TIMM8A is an oncogene and is critical for the tumorigenesis of breast carcinoma.