Programmed cell death and the immune system

Exosomal Tenascin-C primes macrophage pyroptosis amplifying aberrant inflammation during sepsis-induced acute lung injury

Sepsis-induced acute lung injury (ALI) is a serious complication of sepsis and the predominant cause of death. Exosomes released by lung tissue cells critically influence the progression of ALI during sepsis by modulating the inflammatory microenvironment. However, the molecular mechanisms by which exosome-mediated intercellular signaling exacerbates ALI in septic infection remain undefined. Our study found increased levels of exosomal Tenascin-C (TNC) in the plasma of both patients and mice with ALI, showing a strong association with disease progression. By integrating exosomal proteomics with transcriptome sequencing and experimental validation, we elucidated that LPS induce unresolved endoplasmic reticulum stress (ERs) in alveolar epithelial cells (AECs), ultimately leading to the release of exosomal TNC through the activation of PERK-eIF2α and the transcription factor CHOP. In the sepsis mouse model with TNC knockout, we noted a marked reduction in macrophage pyroptosis. Our detailed investigations found that exosomal TNC binds to TLR4 on macrophages, resulting in an augmented production of ROS, subsequent mitochondrial damage, activation of the NF-κB signaling pathway, and induction of DNA damage response. These interconnected events culminate in macrophage pyroptosis, thereby amplifying the release of inflammatory cytokines. Our findings demonstrate that exosomal Tenascin-C, released from AECs under unresolved ER stress, exacerbates acute lung injury by intensifying sepsis-associated inflammatory responses. This research provides new insights into the complex cellular interactions underlying sepsis-induced ALI.

DIMINISHED EXPRESSION OF GLS IN CD4 + T CELLS SERVES AS A PROGNOSTIC INDICATOR ASSOCIATED WITH CUPROPTOSIS IN SEPTIC PATIENTS

ABSTRACT

Objectives: Sepsis is defined as a life-threatening disease associated with a dysfunctional host immune response. Stratified identification of critically ill patients might significantly improve the survival rate. The present study sought to probe molecular markers associated with cuproptosis in septic patients to aid in stratification and improve prognosis. Methods: We studied expression of cuproptosis-related genes (CRGs) using peripheral blood samples from septic patients. Further classification was made by examining levels of expression of these potential CRGs in patients. Coexpression networks were constructed using the Weighted Gene Coexpression Network Analysis (WGCNA) method to identify crucial prognostic CRGs. Additionally, we utilized immune cell infiltration analysis to further examine the immune status of septic patients with different subtypes and its association with the CRGs. scRNA-seq data were also analyzed to verify expression of key CRGs among specific immune cells. Finally, immunoblotting, flow cytometry, immunofluorescence, and CFSE analysis were used to investigate possible regulatory mechanisms. Results: We classified septic patients based on CRG expression levels and found significant differences in prognosis and gene expression patterns. Three key CRGs that may influence the prognosis of septic patients were identified. A decrease in GLS expression was subsequently verified in Jurkat cells, accompanied by a reduction in O-GlcNAc levels, and chelation of copper by tetrathiomolybdate could not rescue the reduction in GLS and O-GLcNAc levels. Moreover, immoderate chelation of copper was detrimental to mitochondrial function, cell viability, and cell proliferation, as well as the immune status of the host. Conclusion: We have identified novel molecular markers associated with cuproptosis, which could potentially function as diagnostic indicators for septic patients. The reversible nature of the observed alterations in FDX1 and LIAS was demonstrated through copper chelation, whereas the correlation between copper and the observed changes in GLS requires further investigation.

Metal-organic framework (MOF)-based materials for pyroptosis-mediated cancer therapy

Pyroptosis is regarded as a promising strategy to modulate tumor immune microenvironments for anticancer therapy. Although pyroptosis inducers have been extensively explored in the biomedical field, their drug resistance, off-targeting capacity, and adverse effects do not fulfill the growing demands of therapy. Nowadays, metal-organic frameworks (MOFs) with unique structures and facile synthesis/functionalization characteristics have shown great potential in anticancer therapy. The flexible choices of metal ions and ligands endow MOFs with inherent anti-cancer efficiency, whereas the porous structures in MOFs make them ideal vehicles for delivering various chemodrug-based pyroptosis inducers. In this review, we provide the latest advances in MOF-based materials to evoke pyroptosis and give a brief but comprehensive review of the different types of MOFs for pyroptosis-mediated cancer therapy. Finally, we also discuss the current challenges of MOF-based pyroptosis inducers and their future prospects in this field.

Self-Assembled Aza-Boron-Dipyrromethene-Based H2S Prodrug for Synergistic Ferroptosis-Enabled Gas and Sonodynamic Tumor Therapies

Glioblastoma multiforme (GBM) is the most aggressive and lethal subtype of gliomas of the central nervous system. The efficacy of sonodynamic therapy (SDT) against GBM is significantly reduced by the expression of apoptosis-inhibitory proteins in GBM cells. In this study, an intelligent nanoplatform (denoted as Aza-BD@PC NPs) based on the aza-boron-dipyrromethene dye and phenyl chlorothionocarbonate-modified DSPE-PEG molecules is developed for synergistic ferroptosis-enabled gas therapy (GT) and SDT of GBM. Once internalized by GBM cells, Aza-BD@PC NPs showed effective cysteine (Cys) consumption and Cys-triggered hydrogen sulfide (H2S) release for ferroptosis-enabled GT, thereby disrupting homeostasis in the intracellular environment, affecting GBM cell metabolism, and inhibiting GBM cell proliferation. Additionally, the released Aza-BD generated abundant singlet oxygen (1O2) under ultrasound irradiation for favorable SDT. In vivo and in vitro evaluations demonstrated that the combined functions of Cys consumption, H2S production, and 1O2 production induced significant death of GBM cells and markedly inhibited tumor growth, with an impressive inhibition rate of up to 97.5%. Collectively, this study constructed a cascade nanoreactor with satisfactory Cys depletion performance, excellent H2S release capability, and prominent reactive oxygen species production ability under ultrasound irradiation for the synergistic ferroptosis-enabled GT and SDT of gliomas.

The role of pyroptosis in heart failure and related traditional chinese medicine treatments

Pyroptosis is a type of programmed cell death that is mediated by both typical and atypical pathways and ultimately leads to the lysis and rupture of cell membranes and the release of proinflammatory factors, triggering an intense inflammatory response. Heart failure (HF) is a serious and terminal stage of various heart diseases. Myocardial hypertrophy, myocardial fibrosis, ventricular remodeling, oxidative stress, the inflammatory response and cardiomyocyte ionic disorders caused by various cardiac diseases are all risk factors for and aggravate HF. Numerous studies have shown that pyroptosis can induce and exacerbate these reactions, causing progression to HF. Therefore, targeting pyroptosis is a promising strategy to treat HF. This paper summarizes the role of pyroptosis in the development of HF and the underlying mechanism involved. Recent research progress on the ability of traditional Chinese medicine (TCM) extracts and formulas to inhibit pyroptosis and treat HF was summarized, and some traditional Chinese medicine extracts and formulas can alleviate different types of HF, including heart failure with preserved ejection fraction (HFpEF), heart failure with reduced ejection fraction (HFrEF), and heart failure with midrange ejection fraction (HFmrEF), by targeting pyroptosis. These findings may provide new ideas and evidence for the treatment or adjuvant treatment of HF by targeting pyroptosis.

Synthetic protein circuits for programmable control of mammalian cell death

Natural cell death pathways such as apoptosis and pyroptosis play dual roles: they eliminate harmful cells and modulate the immune system by dampening or stimulating inflammation. Synthetic protein circuits capable of triggering specific death programs in target cells could similarly remove harmful cells while appropriately modulating immune responses. However, cells actively influence their death modes in response to natural signals, making it challenging to control death modes. Here, we introduce naturally inspired "synpoptosis" circuits that proteolytically regulate engineered executioner proteins and mammalian cell death. These circuits direct cell death modes, respond to combinations of protease inputs, and selectively eliminate target cells. Furthermore, synpoptosis circuits can be transmitted intercellularly, offering a foundation for engineering synthetic killer cells that induce desired death programs in target cells without self-destruction. Together, these results lay the groundwork for programmable control of mammalian cell death.

Ironing out the role of ferroptosis in immunity

Ferroptosis is a type of regulated cell death that drives the pathophysiology of many diseases. Oxidative stress is detectable in many types of regulated cell death, but only ferroptosis involves lipid peroxidation and iron dependency. Ferroptosis originates and propagates from several organelles, including the mitochondria, endoplasmic reticulum, Golgi, and lysosomes. Recent data have revealed that immune cells can both induce and undergo ferroptosis. A mechanistic understanding of how ferroptosis regulates immunity is critical to understanding how ferroptosis controls immune responses and how this is dysregulated in disease. Translationally, more work is needed to produce ferroptosis-modulating immunotherapeutics. This review focuses on the role of ferroptosis in immune-related diseases, including infection, autoimmune diseases, and cancer. We discuss how ferroptosis is regulated in immunity, how this regulation contributes to disease pathogenesis, and how targeting ferroptosis may lead to novel therapies.

The involvement of ROS-regulated programmed cell death in hepatocellular carcinoma

Reactive oxidative species (ROS) is a crucial factor in the regulation of cellular biological activity and function, and aberrant levels of ROS can contribute to the development of a variety of diseases, particularly cancer. Numerous discoveries have affirmed that this process is strongly associated with "programmed cell death (PCD)," which refers to the suicide protection mechanism initiated by cells in response to external stimuli, such as apoptosis, autophagy, ferroptosis, etc. Research has demonstrated that ROS-induced PCD is crucial for the development of hepatocellular carcinoma (HCC). These activities serve a dual function in both facilitating and inhibiting cancer, suggesting the existence of a delicate balance within healthy cells that can be disrupted by the abnormal generation of reactive oxygen species (ROS), thereby influencing the eventual advancement or regression of a tumor. In this review, we summarize how ROS regulates PCD to influence the tumorigenesis and progression of HCC. Studying how ROS-induced PCD affects the progression of HCC at a molecular level can help develop better prevention and treatment methods and facilitate the design of more effective preventative and therapeutic strategies.

Activation of receptor-interacting protein 3-mediated necroptosis accelerates periodontitis in mice

OBJECTIVE

To investigate the involvement and role of receptor-interacting protein 3 (RIP3)-mediated necroptosis in periodontitis.

METHODS

A periodontitis murine model was established by oral infection with Porphyromonas gingivalis, and activation of necroptosis pathway was identified by immunohistochemistry. Adeno-associated virus was used to knock down Rip3 and the effect of Rip3 knockdown on periodontal inflammation was examined by Micro-CT, qRT-PCR and histological staining. In vitro, P. gingivalis-LPS was used to infect fibroblast cell line L929 and siRNA was used to knock down Rip3. Necroptosis pathway signalling and inflammation in cells were detected by cell viability and death assay, Western Blot, qRT-PCR and immunofluorescence analysis.

RESULTS

Phosphorylation of RIP3 and mixed lineage kinase domain-like protein (MLKL) was increased in the periodontal ligament of mice infected with P. gingivalis. RIP3 knockdown reduced osteoclastogenesis and inflammatory cytokines in the periodontal area, and alleviated alveolar bone loss in vivo. In vitro, P. gingivalis-LPS-induced RIP3-mediated necroptosis in L929 cells, and knockdown of RIP3 by siRNA decreased the expression of inflammatory cytokines.

CONCLUSION

RIP3-mediated necroptosis is activated in periodontitis and blocking necroptosis alleviates disease progression, indicating that RIP3 may be a potential target for periodontitis treatment.

Zooming in and Out of Programmed Cell Death in Osteoarthritis: A Scientometric and Visualized Analysis

During the past decade, mounting evidence has increasingly linked programmed cell death (PCD) to the progression and development of osteoarthritis (OA). There is a significant need for a thorough scientometric analysis that recapitulates the relationship between PCD and OA. This study aimed to collect articles and reviews focusing on PCD in OA, extracting data from January 1st, 2013, to October 31st, 2023, using the Web of Science. Various tools, including VOSviewer, CiteSpace, Pajek, Scimago Graphica, and the R package, were employed for scientometric and visualization analyses. Notably, China, the USA, and South Korea emerged as major contributors, collectively responsible for more than 85% of published papers and significantly influencing research in this field. Among different institutions, Shanghai Jiao Tong University, Xi'an Jiao Tong University, and Zhejiang University exhibited the highest productivity. Prolific authors included Wang Wei, Wang Jing, and Zhang Li. Osteoarthritis and Cartilage had the most publications in this area. Keywords related to PCD in OA prominently highlighted 'chondrocytes', 'inflammation', and 'oxidative stress', recognized as pivotal mechanisms contributing to PCD within OA. This study presents the first comprehensive scientometric analysis, offering a broad perspective on the knowledge framework and evolving patterns concerning PCD in relation to OA over the last decade. Such insights can aid researchers in comprehensively understanding this field and provide valuable directions for future explorations.

Anti-inflammatory and immunoregulatory effects of colistin sulphate on human PBMCs

In previous studies, CST has been identified as having an immunostimulatory effect on Caenorhabditis elegans and macrophage of rats. Here, we further investigated its immunomodulatory effects on human peripheral blood mononuclear cells (PBMCs). LPS-stimulated PBMCs inflammatory model was established. Flow cytometry was applied to measure phagocytosis of PBMCs. Cytokine mRNA and protein expression levels of LPS-stimulated PBMCs with or without CST were measured by qRT-PCR and ELISA. The transcriptomic profile of CST-treated PBMCs was investigated by RNA-sequencing. Gene Ontology (GO) and Kyoto Encylopedia of Genes and Genomes (KEGG) were applied to find potential signalling pathways. PBMCs showed a significant increase in phagocytic activity at 6 h after being incubated with CST at the concentration of 10 μg/mL. In the presence of LPS, CST maintained and promoted the expression of TNF-α and chemokine CCL24. The content of pro-inflammatory cytokines, such as IL-1β, IL-6 and IFN-γ, which were released from LPS-stimulated PBMCs, was reduced by CST at 6 h. Anti-inflammatory cytokines, such as IL-4, IL-13 and TGF-β1, were significantly increased by CST at 24 h. A total of 277 differentially expressed immune-related genes (DEIRGs) were detected and cytokine-cytokine receptor interaction was highly enriched. CST presented obvious anti-inflammatory and immunoregulatory effects in LPS-induced PBMCs inflammatory model not only by improving the ability of PBMCs to clear pathogens but also by decreasing pro-inflammatory cytokines and increasing anti-inflammatory cytokines. And the mechanism may be related to cytokine-cytokine receptor interaction.

Functional diversity of apoptotic vesicle subpopulations from bone marrow mesenchymal stem cells in tissue regeneration

Apoptosis releases numerous apoptotic vesicles that regulate processes such as cell proliferation, immunity, and tissue regeneration and repair. Now, it has also emerged as an attractive candidate for biotherapeutics. However, apoptotic vesicles encompass a diverse range of subtypes, and it remains unclear which specific subtypes play a pivotal role. In this study, we successfully isolated different apoptotic vesicle subtypes based on their sizes and characterized them using NTA and TEM techniques, respectively. We compared the functional variances among the distinct subtypes of apoptotic vesicles in terms of stem cell proliferation, migration, and differentiation, as well as for endothelial cell and macrophage function, effectively identifying subtypes that exhibit discernible functional differences. ApoSEV (with diameter <1000 nm) promoted stem cell proliferation, migration, and multi-potent differentiation, and accelerated skin wound healing of diabetes mouse model, while apoBD (with diameter >1000 nm) played the opposite effect on cell function and tissue regeneration. Lastly, employing protein analysis and gene sequencing techniques, we elucidated the intrinsic mechanisms underlying these differences between different subtypes of apoEVs. Collectively, this study identified that apoptotic vesicle subtypes possessed distinct bio-functions in regulating stem cell function and behaviour and modulating tissue regeneration, which primarily attribute to the distinct profiling of protein and mRNA in different subtypes. This comprehensive analysis of specific subtypes of apoEVs would provide novel insights for potential therapeutic applications in cell biology and tissue regeneration.

Reinforced Immunogenic Endoplasmic Reticulum Stress and Oxidative Stress via an Orchestrated Nanophotoinducer to Boost Cancer Photoimmunotherapy

Cancer progression and treatment-associated cellular stress impairs therapeutic outcome by inducing resistance. Endoplasmic reticulum (ER) stress is responsible for core events. Aberrant activation of stress sensors and their downstream components to disrupt homeostasis have emerged as vital regulators of tumor progression as well as response to cancer therapy. Here, an orchestrated nanophotoinducer (ERsNP) results in specific tumor ER-homing, induces hyperthermia and mounting oxidative stress associated reactive oxygen species (ROS), and provokes intense and lethal ER stress upon near-infrared laser irradiation. The strengthened "dying" of ER stress and ROS subsequently induce apoptosis for both primary and abscopal B16F10 and GL261 tumors, and promote damage-associated molecular patterns to evoke stress-dependent immunogenic cell death effects and release "self-antigens". Thus, there is a cascade to activate maturation of dendritic cells, reprogram myeloid-derived suppressor cells to manipulate immunosuppression, and recruit cytotoxic T lymphocytes and effective antitumor response. The long-term protection against tumor recurrence is realized through cascaded combinatorial preoperative and postoperative photoimmunotherapy including the chemokine (C-C motif) receptor 2 antagonist, ERsNP upon laser irradiation, and an immune checkpoint inhibitor. The results highlight great promise of the orchestrated nanophotoinducer to exert potent immunogenic cell stress and death by reinforcing ER stress and oxidative stress to boost cancer photoimmunotherapy.

CD4 + T cells ferroptosis is associated with the development of sepsis in severe polytrauma patients

BACKGROUND

Immunological disorder remains a great challenge in severe poly-trauma, in which lymphopenia is an important contributor. The purpose of present study is to explore whether ferroptosis, a new manner of programmed cell death (PCD), is involved in the lymphocyte depletion and predictive to the adverse prognosis of severe injuries.

PATIENTS AND METHODS

Severe polytrauma patients admitted from January 2022 to December 2022 in our trauma center were prospectively investigated. Peripheral blood samples were collected at admission (day 1), day 3 and day 7 from them. Included patients were classified based on whether they developed sepsis or not. Clinical outcomes, systematic inflammatory response, lymphocyte subpopulation, CD4 + T cell ferroptosis were collected, detected and analyzed.

RESULTS

Notable lymphopenia was observed on the first day after severe trauma and failed to normalize on the 7th day if patients were complicated with sepsis, in which CD4 + T cell was the subset of lymphocyte that depleted most pronouncedly. Lymphocyte loss was significantly correlated with the acute and biphasic systemic inflammatory response. Ferroptosis participated in the death of CD4 + T cells, potentially mediated by the downregulation of xCT-GSH-GPX4 pathway. CD4 + T cells ferroptosis had a conducive predicting value for the development of sepsis following severe trauma.

CONCLUSIONS

CD4 + T cells ferroptosis occurs early in the acute stage of severe polytrauma, which may become a promising biomarker and therapeutic target for post-traumatic sepsis.

DAMPs and radiation injury

The heightened risk of ionizing radiation exposure, stemming from radiation accidents and potential acts of terrorism, has spurred growing interests in devising effective countermeasures against radiation injury. High-dose ionizing radiation exposure triggers acute radiation syndrome (ARS), manifesting as hematopoietic, gastrointestinal, and neurovascular ARS. Hematopoietic ARS typically presents with neutropenia and thrombocytopenia, while gastrointestinal ARS results in intestinal mucosal injury, often culminating in lethal sepsis and gastrointestinal bleeding. This deleterious impact can be attributed to radiation-induced DNA damage and oxidative stress, leading to various forms of cell death, such as apoptosis, necrosis and ferroptosis. Damage-associated molecular patterns (DAMPs) are intrinsic molecules released by cells undergoing injury or in the process of dying, either through passive or active pathways. These molecules then interact with pattern recognition receptors, triggering inflammatory responses. Such a cascade of events ultimately results in further tissue and organ damage, contributing to the elevated mortality rate. Notably, infection and sepsis often develop in ARS cases, further increasing the release of DAMPs. Given that lethal sepsis stands as a major contributor to the mortality in ARS, DAMPs hold the potential to function as mediators, exacerbating radiation-induced organ injury and consequently worsening overall survival. This review describes the intricate mechanisms underlying radiation-induced release of DAMPs. Furthermore, it discusses the detrimental effects of DAMPs on the immune system and explores potential DAMP-targeting therapeutic strategies to alleviate radiation-induced injury.

Novel lncRNA regulatory elements in milk somatic cells of Holstein dairy cows associated with mastitis

Despite regulatory elements such as long non - coding RNAs representing most of the transcriptome, the functional understanding of long non - coding RNAs in relation to major health conditions including bovine mastitis is limited. This study examined the milk somatic cell transcriptome from udder quarters of 6 Holstein dairy cows to identify differentially expressed long non - coding RNAs using RNA - Sequencing. Ninety - four differentially expressed long non - coding RNAs are identified, 5 of which are previously annotated for gene name and length, 11 are annotated for gene name and 78 are novel, having no gene name or length previously annotated. Significant inflammatory response and regulation of immune response pathways (false discovery rate < 0.05) are associated with the differentially expressed long non - coding RNAs. QTL annotation analysis revealed 31 QTL previously annotated in the genomic regions of the 94 differentially expressed long non - coding RNAs, and the majority are associated with milk traits. This research provides a better understanding of long non - coding RNAs regulatory elements in milk somatic cells, which may enhance current breeding strategies for more adaptable or high mastitis resistant cattle.

Cell death proteins in sepsis: key players and modern therapeutic approaches

Cell death proteins play a central role in host immune signaling during sepsis. These interconnected mechanisms trigger cell demise via apoptosis, necroptosis, and pyroptosis while also driving inflammatory signaling. Targeting cell death mediators with novel therapies may correct the dysregulated inflammation seen during sepsis and improve outcomes for septic patients.

The Dual Roles of Activating Transcription Factor 3 (ATF3) in Inflammation, Apoptosis, Ferroptosis, and Pathogen Infection Responses

Transcription factors are pivotal regulators in the cellular life process. Activating transcription factor 3 (ATF3), a member of the ATF/CREB (cAMP response element-binding protein) family, plays a crucial role as cells respond to various stresses and damage. As a transcription factor, ATF3 significantly influences signal transduction regulation, orchestrating a variety of signaling pathways, including apoptosis, ferroptosis, and cellular differentiation. In addition, ATF3 serves as an essential link between inflammation, oxidative stress, and immune responses. This review summarizes the recent advances in research on ATF3 activation and its role in regulating inflammatory responses, cell apoptosis, and ferroptosis while exploring the dual functions of ATF3 in these processes. Additionally, this article discusses the role of ATF3 in diseases related to pathogenic microbial infections. Our review may be helpful to better understand the role of ATF3 in cellular responses and disease progression, thus promoting advancements in clinical treatments for inflammation and oxidative stress-related diseases.

Gasdermin E dictates inflammatory responses by controlling the mode of neutrophil death

Both lytic and apoptotic cell death remove senescent and damaged cells in living organisms. However, they elicit contrasting pro- and anti-inflammatory responses, respectively. The precise cellular mechanism that governs the choice between these two modes of death remains incompletely understood. Here we identify Gasdermin E (GSDME) as a master switch for neutrophil lytic pyroptotic death. The tightly regulated GSDME cleavage and activation in aging neutrophils are mediated by proteinase-3 and caspase-3, leading to pyroptosis. GSDME deficiency does not alter neutrophil overall survival rate; instead, it specifically precludes pyroptosis and skews neutrophil death towards apoptosis, thereby attenuating inflammatory responses due to augmented efferocytosis of apoptotic neutrophils by macrophages. In a clinically relevant acid-aspiration-induced lung injury model, neutrophil-specific deletion of GSDME reduces pulmonary inflammation, facilitates inflammation resolution, and alleviates lung injury. Thus, by controlling the mode of neutrophil death, GSDME dictates host inflammatory outcomes, providing a potential therapeutic target for infectious and inflammatory diseases.

Mechanisms and otoprotective strategies of programmed cell death on aminoglycoside-induced ototoxicity

Aminoglycosides are commonly used for the treatment of life-threatening bacterial infections, however, aminoglycosides may cause irreversible hearing loss with a long-term clinical therapy. The mechanism and prevention of the ototoxicity of aminoglycosides are still limited although amounts of studies explored widely. Specifically, advancements in programmed cell death (PCD) provide more new perspectives. This review summarizes the general signal pathways in programmed cell death, including apoptosis, autophagy, and ferroptosis, as well as the mechanisms of aminoglycoside-induced ototoxicity. Additionally, novel interventions, especially gene therapy strategies, are also investigated for the prevention or treatment of aminoglycoside-induced hearing loss with prospective clinical applications.

Therapeutic potential of PANoptosis: innate sensors, inflammasomes, and RIPKs in PANoptosomes

The innate immune system initiates cell death pathways in response to pathogens and cellular stress. Cell death can be either non-lytic (apoptosis) or lytic (PANoptosis, pyroptosis, and necroptosis). PANoptosis has been identified as an inflammatory, lytic cell death pathway driven by caspases and RIPKs that is regulated by PANoptosome complexes, making it distinct from other cell death pathways. Several PANoptosome complexes (including ZBP1-, AIM2-, RIPK1-, and NLRP12-PANoptosomes) have been characterized to date. Furthermore, PANoptosis is implicated in infectious and inflammatory diseases, cancers, and homeostatic perturbations. Therefore, targeting its molecular components offers significant potential for therapeutic development. This review covers PANoptosomes and their assembly, PANoptosome-mediated cell death mechanisms, and ongoing progress in developing therapeutics that target PANoptosis.

Ferroptosis in immunostimulation and immunosuppression

Ferroptosis is a form of iron-dependent regulated cell death characterized by the accumulation of toxic lipid peroxides, particularly in the plasma membrane, leading to lytic cell death. While it plays a crucial role in maintaining the overall health and proper functioning of multicellular organisms, it can also contribute to tissue damage and pathological conditions. Although ferroptotic damage is generally recognized as an immunostimulatory process associated with the release of damage-associated molecular patterns (DAMPs), the occurrence of ferroptosis in immune cells or the release of immunosuppressive molecules can result in immune tolerance. Consequently, there is ongoing exploration of targeting the upstream signals or the machinery of ferroptosis to therapeutically enhance or inhibit the immune response. In addition to introducing the core molecular mechanisms of ferroptosis, we will focus on the immune characteristics of ferroptosis in pathological conditions, particularly in the context of infection, sterile inflammation, and tumor immunity.

Comprehensive Analysis of PANoptosis-Related Gene Signature of Ulcerative Colitis

Accumulating evidence shows that the abnormal increase in the mortality of intestinal epithelial cells (IECs) caused by apoptosis, pyroptosis, and necroptosis is closely related to the function of mucous membrane immunity and barrier function in patients with ulcerative colitis (UC). As a procedural death path that integrates the above-mentioned many deaths, the role of PANoptosis in UC has not been clarified. This study aims to explore the characterization of PANoptosis patterns and determine the potential biomarkers and therapeutic targets. We constructed a PANoptosis gene set and revealed significant activation of PANoptosis in UC patients based on multiple transcriptome profiles of intestinal mucosal biopsies from the GEO database. Comprehensive bioinformatics analysis revealed five key genes (ZBP1, AIM2, CASP1/8, IRF1) of PANoptosome with good diagnostic value and were highly correlated with an increase in pro-inflammatory immune cells and factors. In addition, we established a reliable ceRNA regulatory network of PANoptosis and predicted three potential small-molecule drugs sharing calcium channel blockers that were identified, among which flunarizine exhibited the highest correlation with a high binding affinity to the targets. Finally, we used the DSS-induced colitis model to validate our findings. This study identifies key genes of PANoptosis associated with UC development and hypothesizes that IRF1 as a TF promotes PANoptosome multicomponent expression, activates PANoptosis, and then induces IECs excessive death.

Apoptotic signaling clears engineered Salmonella in an organ-specific manner

Pyroptosis and apoptosis are two forms of regulated cell death that can defend against intracellular infection. When a cell fails to complete pyroptosis, backup pathways will initiate apoptosis. Here, we investigated the utility of apoptosis compared to pyroptosis in defense against an intracellular bacterial infection. We previously engineered Salmonella enterica serovar Typhimurium to persistently express flagellin, and thereby activate NLRC4 during systemic infection in mice. The resulting pyroptosis clears this flagellin-engineered strain. We now show that infection of caspase-1 or gasdermin D deficient macrophages by this flagellin-engineered S. Typhimurium induces apoptosis in vitro. Additionally, we engineered S. Typhimurium to translocate the pro-apoptotic BH3 domain of BID, which also triggers apoptosis in macrophages in vitro. During mouse infection, the apoptotic pathway successfully cleared these engineered S. Typhimurium from the intestinal niche but failed to clear the bacteria from the myeloid niche in the spleen or lymph nodes. In contrast, the pyroptotic pathway was beneficial in defense of both niches. To clear an infection, cells may have specific tasks that they must complete before they die; different modes of cell death could initiate these 'bucket lists' in either convergent or divergent ways.

Caspase-9 inhibition triggers Hsp90-based chemotherapy-mediated tumor intrinsic innate sensing and enhances antitumor immunity

BACKGROUND

Antineoplastic chemotherapies are dramatically efficient when they provoke immunogenic cell death (ICD), thus inducing an antitumor immune response and even tumor elimination. However, activated caspases, the hallmark of most cancer chemotherapeutic agents, render apoptosis immunologically silent. Whether they are dispensable for chemotherapy-induced cell death and the apoptotic clearance of cells in vivo is still elusive.

METHODS

A rational cell-based anticancer drug library screening was performed to explore the immunogenic apoptosis pathway and therapeutic targets under apoptotic caspase inhibition. Based on this screening, the potential of caspase inhibition in enhancing chemotherapy-induced antitumor immunity and the mechanism of actions was investigated by various cells and mouse models.

RESULTS

Heat shock protein 90 (Hsp90) inhibition activates caspases in tumor cells to produce abundant genomic and mitochondrial DNA fragments and results in cell apoptosis. Meanwhile, it hijacks Caspase-9 signaling to suppress intrinsic DNA sensing. Pharmacological blockade or genetic deletion of Caspase-9 causes tumor cells to secrete interferon (IFN)-β via tumor intrinsic mitochondrial DNA/the second messenger cyclic GMP-AMP (cGAS) /stimulator of interferon genes (STING) pathway without impairing Hsp90 inhibition-induced cell death. Importantly, both Caspase-9 and Hsp90 inhibition triggers an ICD, leading to the release of numerous damage-associated molecular patterns such as high-mobility group box protein 1, ATP and type I IFNs in vitro and remarkable antitumor effects in vivo. Moreover, the combination treatment also induces adaptive resistance by upregulating programmed death-ligand 1 (PD-L1). Additional PD-L1 blockade can further overcome this acquired immune resistance and achieve complete tumor regression.

CONCLUSIONS

Blockade of Caspase-9 signaling selectively provokes Hsp90-based chemotherapy-mediated tumor innate sensing, leading to CD8+ T cell-dependent tumor control. Our findings implicate that pharmacological modulation of caspase pathway increases the tumor-intrinsic innate sensing and immunogenicity of chemotherapy-induced apoptosis, and synergizes with immunotherapy to overcome adaptive resistance.

Mesenchymal stem cells ameliorate H9N2-induced acute lung injury by inhibiting caspase-3-GSDME-mediated pyroptosis of lung alveolar epithelial cells

Influenza A virus infection mediates the host's excessive immune response, wherein caspase-3-GSDME-mediated pyroptosis of lung alveolar epithelial cells can contribute to inducing cytokine storm, leading to acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). Numerous studies have shown that mesenchymal stem cells (MSCs) possess potent immunomodulatory abilities and can mitigate virus-induced cytokine storm and lung injury. However, the role of MSCs in lung pyroptosis remains poorly understood. In this study, we established an ALI model using a mouse-adapted strain of avian influenza virus H9N2 (MA01) and intervened by injecting appropriate bone marrow-derived mesenchymal stem cells (BMMSCs) into the mouse's trachea. The results obtained from animal experiments demonstrated that BMMSCs prevented and ameliorated ALI by inhibiting Caspase-3-GSDME-mediated pyroptosis of lung epithelial cells as well as hypercytokinemia. Similarly, corresponding results were observed in vitro, where BMMSCs and the lung epithelial cell line MLE-12 cells were co-cultured in a transwell compartment. Additionally, the caspase-3 inhibitor Z-DEVD-FMK could block MA01-induced GSDME activation. Furthermore, by combining RNA-Seq data with in vitro and in vivo results, we also discovered that MA01-induced pyroptosis is associated with the BAK/BAX-dependent mitochondrial apoptosis pathway. Notably, BMMSCs exhibit the ability to interfere with this signaling pathway. In conclusion, this study provides novel theoretical support for the utilization of BMMSCs in the treatment of ALI induced by influenza.

Protective Properties of S-layer Protein 2 from Lactobacillus crispatus 2029 against Candida albicans Infections

Previously, the protective role of the S-layer protein 2 (Slp2) of the vaginal Lactobacillus crispatus 2029 (LC2029) strain against foodborne pathogens Campylobacter jejuni, Salmonella enterica serovar Enteritidis, and Escherichia coli O157:H was demonstrated. We demonstrate the new roles of the Slp2-positive LC2029 strain and soluble Slp2 against C. albicans infections. We show that LC2029 bacteria can adhere to the surface of the cervical epithelial HeLa cells, prevent their contact with C. albicans, and block yeast transition to a pathogenic hyphal form. Surface-bound Slp2 provides the ability for LC2029 to co-aggregate with various C. albicans strains, including clinical isolates. C. albicans-induced necrotizing epithelial damage is reduced by colonization with the Slp2-positive LC2029 strain. Slp2 inhibits the adhesion of various strains of C. albicans to different human epithelial cells, blocks yeast transition to a pathogenic hyphal form, and prevents the colonization and pathogenic infiltration of mucosal barriers. Only Slp2 and LC2029 bacteria stimulate the production of protective human β-defensin 3 in various epithelial cells. These findings support the anti-Candida albicans potential of the probiotic LC2029 strain and Slp2 and form the basis for further research on their ability to prevent and manage invasive Candida infections.

Identification of anti-cancer organometallic compounds by inhibition of BCL-2/Bax interactions

Apoptosis is regulated by the BCL-2 family, which includes the anti-apoptotic and pro-apoptotic proteins (Bax, Bok, Bak, etc.). These proteins often interact in dimers and act as apoptotic switches. Anti-apoptotic proteins, such as BCL-2, block the functions of these pro-apoptotic proteins. The pro-apoptotic and anti-apoptotic protein-protein interactions must be inhibited to prevent tumor cells from escaping apoptosis. This method has been used to develop anticancer drugs by inhibiting BCL-2 with both natural and synthetic compounds. Metal-containing compounds were used as pharmaceuticals for human cancer patients for a long time, and cisplatin was the first candidate of this class. Drug design, however, needs to pay more attention to metal complexes. We have studied the X-ray crystal structure of the BCL-2 protein in detail and identified the hydrophobic nature of the site with two less solvent-accessible sites. Based on the hydrophobic nature of the compounds, 74 organometallic compounds with X-ray crystallographically characterized bioactivity (including anticancer activity) were selected from the Cambridge crystallographic database. For testing, molecular docking was used to determine which compound was most effective against the BCL-2 protein. Organometallic compounds (benzene)-chloro-(1-{[(9H-fluoren-2-yl)imino]methyl}naphthalen-2-olato)-ruthenium (2), (1-((1,1'-biphenyl)-4-yl)-2,3,4,5-tetramethylcyclopentadienyl)-chloro-(4,4'-dimethyl-2,2'-bipyridine)-rhodium hexafluorophosphate (37), (μ-1,1'-(butane-1,4-diyl)bis(3-oxy-2-methylpyridin-4(1H)-one))-dichloro-bis(pentamethyl-cyclopentadienyl)-di-rhodium tetrahydrate (46), (μ-1,1'-(butane-1,4-diyl)bis(3-oxy-2-methylpyridin-4(1H)-one))-dichloro-bis(pentamethyl-cyclopentadienyl)-di-iridium (47) etc are found to be important compounds in this study. The capability of different types of complex interactions was identified using Hirshfeld surface analysis of the complexes. A NCI plot was conducted to understand the nature of the interaction between complex amino acids and active-site amino acids. A DFT study was conducted to examine the stability and chemical reactivity of the selected complexes. Using this study, one suitable hydrophobic lead anti-cancer organometallic pharmaceutical was found that binds at the less solvent-accessible hydrophobic site of BCL-2.

Modes and Mechanisms of Salivary Gland Epithelial Cell Death in Sjogren's Syndrome

Sjogren's syndrome is an autoimmune disease in middle and old-aged women with a dry mucosal surface, which is caused by the dysfunction of secretory glands, such as the oral cavity, eyeballs, and pharynx. Pathologically, Sjogren's syndrome are characterized by lymphocyte infiltration into the exocrine glands and epithelial cell destruction caused by autoantibodies Ro/SSA and La/SSB. At present, the exact pathogenesis of Sjogren's syndrome is unclear. Evidence suggests epithelial cell death and the subsequent dysfunction of salivary glands as the main causes of xerostomia. This review summarizes the modes of salivary gland epithelial cell death and their role in Sjogren's syndrome progression. The molecular mechanisms involved in salivary gland epithelial cell death during Sjogren's syndrome as potential leads to treating the disease are also discussed.

PANoptosis in cancer, the triangle of cell death

BACKGROUND

PANoptosis is a novel form of programmed cell death (PCD) found in 2019 that is regulated by the PANoptosome. PANoptosis combines essential features of pyroptosis, apoptosis, and necroptosis, forming a "death triangle" of cells. While apoptosis, pyroptosis, and necroptosis have been extensively studied for their roles in human inflammatory diseases and many other clinical conditions, historically they were considered as independent processes. However, emerging evidence indicates that these PCDs exhibit cross talk and interactions, resulting in the development of the concept of PANoptosis.

METHODS

In this review, we offer a concise summary of the fundamental mechanisms of apoptosis, pyroptosis, and necroptosis. We subsequently introduce the notion of PANoptosis and detail the assembly mechanism of the PANoptosome complex which is responsible for inducing cell death. We also describe some regulatory networks of PANoptosis.

RESULTS

PANoptosis now has been associated with various human diseases including cancer. Although the exact function of PANoptosis in each tumor is not fully understood, it represents a prospective avenue for cancer therapy, offering promise for advancements in cancer therapy.

CONCLUSIONS

In the future, in-depth study of PANoptosis will continue to help us in understanding the fundamental processes underlying cell death and provide scientific support for cancer research.

Assessing the double-edged of extracellular signal-regulated kinase/CCAAT-enhancer-binding protein beta signaling pathway in arsenic-induced skin damage and its potential foodborne interventions

Arsenic exposure is a major environmental public health challenge worldwide. As typical manifestations for arsenic exposure, the pathogenesis of arsenic-induced skin lesions has not been fully elucidated, as well as the lack of effective control measures. In this study, we first determined the short-term and high-dose arsenic exposure can increase the apoptosis rates, while long-term low-dose arsenic exposure decrease the apoptosis rates. Then, the HaCaT cells with knockdown and overexpression of CCAAT-enhancer-binding protein β (CEBPB) and extracellular signal-regulated kinase (ERK) were constructed. The results demonstrate that knockdown of CEBPB and ERK can reduce NaAsO2 -induced cell apoptosis by inhibiting ERK/CEBPB signaling pathway and vice versa. Further cells were treated with Kaji-Ichigoside F1 (KF1). The results clearly show that KF1 can decrease the arsenic-induced cell apoptosis rates and the expression of ERK/CEBPB signaling pathway-related genes. These results provide evidence that ERK/CEBPB signaling pathway acts as a double-edged sword in arsenic-induced skin damage. Another interesting finding was that KF1 can alleviate arsenic-induced skin cell apoptosis by inhibiting the ERK/CEBPB signaling pathway. This study will contribute to a deeper understanding of the mechanisms of arsenic-induced skin cell apoptosis, and our findings will help to identify a potential food-borne intervention in arsenic detoxification.

Innate immune inflammatory cell death: PANoptosis and PANoptosomes in host defense and disease

Regulated cell death (RCD) triggered by innate immune activation is an important strategy for host survival during pathogen invasion and perturbations of cellular homeostasis. There are two main categories of RCD, including nonlytic and lytic pathways. Apoptosis is the most well-characterized nonlytic RCD, and the inflammatory pyroptosis and necroptosis pathways are among the best known lytic forms. While these were historically viewed as independent RCD pathways, extensive evidence of cross-talk among their molecular components created a knowledge gap in our mechanistic understanding of RCD and innate immune pathway components, which led to the identification of PANoptosis. PANoptosis is a unique innate immune inflammatory RCD pathway that is regulated by PANoptosome complexes upon sensing pathogens, pathogen-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs) or the cytokines produced downstream. Cytosolic innate immune sensors and regulators, such as ZBP1, AIM2 and RIPK1, promote the assembly of PANoptosomes to drive PANoptosis. In this review, we discuss the molecular components of the known PANoptosomes and highlight the mechanisms of PANoptosome assembly, activation and regulation identified to date. We also discuss how PANoptosomes and mutations in PANoptosome components are linked to diseases. Given the impact of RCD, and PANoptosis specifically, across the disease spectrum, improved understanding of PANoptosomes and their regulation will be critical for identifying new therapeutic targets and strategies.

Development of an immunogenic cell death prognostic signature for predicting clinical outcome and immune infiltration characterization in stomach adenocarcinoma

Stomach adenocarcinoma (STAD) is a common gastric histological cancer type with a high mortality rate. Immunogenic cell death (ICD) plays a key factor during carcinogenesis progress, whereas the prognostic value and role of ICD-related genes (ICDRGs) in STAD remain unclear. The MSigDB database collecting ICDRGs were selected by univariate Cox regression analysis and LASSO algorithm to establish a novel risk model. The Kaplan-Meier survival analysis indicated a significant difference of OS rate of patients by risk score stratification. ESTIMATE, CIBERSORT, and single sample gene set enrichment analysis (ssGSEA) algorithms were conducted to estimate the immune infiltration landscape by risk stratification. Subgroup analysis and tumor mutation burden analysis were also analyzed to identify characteristics between groups. Differences in therapeutic responsiveness to chemotherapeutic drugs and targeted drugs were also analyzed between high-risk group and low-risk group. The impact of one ICDRG, GPX1, on the proliferation, migration and invasiveness of was confirmed by in vitro experiments in GC cells to test the reliability of bioinformatics results. This study gives evidence of the involvement of ICD process in STAD and provides a new perspective for further accurate assessment of prognosis and therapeutic efficacy in STAD patients. Stomach adenocarcinoma (STAD) is a common gastric histological cancer type with a high mortality rate. Immunogenic cell death (ICD) plays a key factor during carcinogenesis progress, whereas the prognostic value and role of ICD-related genes (ICDRGs) in STAD remains unclear. The MSigDB database collected ICDRGs were selected by univariate Cox regression analysis and LASSO algorithm to establish a novel risk model. The Kaplan-Meier survival analysis indicated a significant difference of OS rate of patients by risk score stratification. ESTIMATE, CIBERSORT, and single sample gene set enrichment analysis (ssGSEA) algorithms were conducted to estimate the immune infiltration landscape by risk stratification. Subgroup analysis and tumor mutation burden analysis were also analyzed to identify characteristics between groups. Differences in therapeutic responsiveness to chemotherapeutic drugs and targeted drugs were also analyzed between high-risk group and low-risk group. The impact of one ICDRG, GPX1, on the proliferation, migration and invasiveness of was confirmed by in vitro experiments in GC cells to test the reliability of bioinformatics results. This study gives evidence of the involvement of ICD process in STAD and provides a new perspective for further accurate assessment of prognosis and therapeutic efficacy in STAD patients.

Piperlongumine induces apoptosis and autophagy via the PI3K/Akt/mTOR pathway in KB human cervical cancer cells

Natural products are continuously being researched to develop safe and effective treatment options for cervical cancer, the fourth most common cancer in women. Piperlongumine (PL), an amide alkaloid mainly present in long pepper, exhibits neuroprotective and anti-cancer properties. However, the specific effect of PL in cervical cancer and the relationship between the anti-cancer pathway and autophagy remain unclear. Therefore, we aimed to investigate PL-induced apoptosis in KB human cervical cancer cells and the relationship between apoptosis and autophagy therein. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and wound-healing assays showed that PL treatment suppressed KB cell viability and proliferation. Apoptosis was identified through 4',6-diamidino-2-phenylindole and annexin V-propidium iodide staining, increased cleaved-poly (ADP-ribose) polymerase and Bcl-2 associated X levels, and decreased B cell lymphoma 2 levels. Acridine orange staining and increased microtubule-associated protein 1A/1B-light chain 3-II and Beclin-1 levels confirmed autophagy. We determined that KB cell-related autophagy exerted cytoprotective effects using the autophagy inhibitors 3-methyladenine and hydroxychloroquine. PL treatment promoted apoptosis by inhibiting the phosphatidylinositol-3-kinase (PI3K)/protein kinase B/mammalian target of rapamycin pathway in KB cells; inhibiting the pathway using PI3K inhibitors increased autophagy. We suggest that PL is a potential natural anticancer agent for cervical cancer treatment.

Activation of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 6 by Porphyromonas gingivalis regulates programmed cell death in epithelium

Background/purpose

Gingival epithelial cells form a physiological barrier against bacterial invasion. Programmed cell death (PCD) regulated by pathogen precognition receptors (PRRs) lead to tissue destruction and is closely related to inflammatory diseases. The purpose of this study was to investigate whether nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 6 (NLRP6) expresses in periodontal epithelium and induces PCD of epithelial cells infected by Porphyromonas gingivalis (P. gingivalis), therefore involves in periodontitis.

Material and methods

The expression of NLRP6 was detected in periodontal epithelium from human gingival sections and HaCaT cells stimulated by P. gingivalis. NLRP6 was over-expressed by adenovirus infection in HaCaT or knocked down by siRNA in P. gingivalis infected HaCaT, and the cell death was observed by transmission electron microscopy and flow cytometry analysis. In addition, qPCR and Western blot were performed to determine the expression of NLRP6 and the pyroptosis excutors, caspase-1 and gasdermin D. Enzyme-linked immunosorbent assay were performed to detect the secretion of IL-1β and IL-18.

Results

NLRP6 was up-regulated in both gingival epithelium of patients with periodontitis and P. gingivalis infected HaCaT. Over-expression of NLRP6 in HaCaT led to caspase-1 dependent pyroptosis. Interestingly, knockdown of NLRP6 with siRNA followed by P. gingivalis stimulation inhibited pyroptosis and induced apoptosis.

Conclusion

Up-regulation of NLRP6 by P. gingivalis in HaCaT led to pyroptosis, while knocking down NLRP6 inhibited pyroptosis and induced apoptosis, which indicated this PRR may play a crucial role in periodontitis by regulating PCD in periodontal epithelium.

Nanomedicine-induced programmed cell death enhances tumor immunotherapy

BACKGROUND

There has been widespread concern about the high cancer mortality rate and the shortcomings of conventional cancer treatments. Immunotherapy is a novel oncology therapy with high efficiency and low side effects, which is a revolutionary direction for clinical oncology treatment. However, its clinical effectiveness is uneven. Based on the redefinition and reclassification of programmed cell death (PCD) (divided into necroptosis, ferroptosis, pyroptosis, and autophagy), the role of nanomedicine-induced PCD in cancer therapy has also received significant attention. Clinical and preclinical studies have begun to combine PCD with immunotherapy.

AIM OF REVIEW

In this article, we present recent research in tumor immunotherapy, provide an overview of how nanomedicine-induced PCD is involved in tumor therapy, and review how nanomedicine-induced PCD can improve the limitations of immunotherapy to enhance tumor immunotherapy. The future development of nanomedicine-mediated PCD tumor therapy and tumor immunotherapy is also proposed Key scientific concepts of overview Nanomedicine-induced PCD is a prospective method of tumor immunotherapy. Nanomedicines increase tumor site penetration and targeting ability, and nanomedicine-mediated PCD activation can stimulate powerful anti-tumor immune effects, which has a good contribution to immunotherapy of tumors.

A cytotoxic T cell inspired oncolytic nanosystem promotes lytic cell death by lipid peroxidation and elicits antitumor immune responses

Lytic cell death triggers an antitumour immune response. However, cancer cells evade lytic cell death by several mechanisms. Moreover, a prolonged and uncontrolled immune response conversely leads to T-cell exhaustion. Therefore, an oncolytic system capable of eliciting an immune response by killing cancer cells in a controlled manner is needed. Here, we establish a micro-scale cytotoxic T-cell-inspired oncolytic system (TIOs) to precisely lyse cancer cells by NIR-light-controlled lipid peroxidation. Our TIOs present antigen-based cell recognition, tumour-targeting and catalytic cell-lysis ability; thus, the TIOs induce oncolysis in vivo. We apply TIOs to preclinical cancer models, showing anti-tumor activity with negligible side-effects. Tumour regression is correlated with a T-cell based anti-tumour immune response and TIOs also improve responses to anti-PD-1 therapy or STING activation. Our study provides insights to design oncolytic systems for antitumour immunity. Moreover, activation of STING can reverse T-cell exhaustion in oncolysis.

Yeast polysaccharide mitigated oxidative injury in broilers induced by mixed mycotoxins via regulating intestinal mucosal oxidative stress and hepatic metabolic enzymes

This study was aimed to investigate the effects of yeast polysaccharides (YPS) on growth performance, intestinal health, and aflatoxin metabolism in livers of broilers fed diets naturally contaminated with mixed mycotoxins (MYCO). A total of 480 one-day-old Arbor Acre male broilers were randomly allocated into a 2 × 3 factorial arrangement of treatments (8 replicates with 10 birds per replicate) for 6 wk to assess the effects of 3 levels of YPS (0, 1, or 2 g/kg) on the broilers fed diets contaminated with or without MYCO (95 μg/kg aflatoxin B1, 1.5 mg/kg deoxynivalenol, and 490 μg/kg zearalenone). Results showed that mycotoxins contaminated diets led to significant increments in serum malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, mRNA expressions of TLR4 and 4EBP1 associated with oxidative stress, mRNA expressions of CYP1A1, CYP1A2, CYP2A6, and CYP3A4 associated with hepatic phase Ⅰ metabolizing enzymes, mRNA expressions of p53 associated with hepatic mitochondrial apoptosis, and AFB1 residues in the liver (P < 0.05); meanwhile dietary MYCO decreased the jejunal villus height (VH), villus height/crypt depth (VH/CD), the activity of serum total antioxidant capacity (T-AOC), mRNA expressions of jejunal HIF-1α, HMOX, and XDH associated with oxidative stress, mRNA expressions of jejunal CLDN1, ZO1, and ZO2, and mRNA expression of GST associated with hepatic phase Ⅱ metabolizing enzymes of broilers (P < 0.05). Notably, the adverse effects induced by MYCO on broilers were mitigated by supplementation with YPS. Dietary YPS supplementation reduced the concentrations of serum MDA and 8-OHdG, jejunal CD, mRNA expression of jejunal TLR2, and 4EBP1, hepatic CYP1A2, and p53, and the AFB1 residues in the liver (P < 0.05), and elevated the serum T-AOC and SOD, jejunal VH, and VH/CD, and mRNA expression of jejunal XDH, hepatic GST of broilers (P < 0.05). There were significant interactions between MYCO and YPS levels on the growth performance (BW, ADFI, ADG, and F/G) at d 1 to 21, d 22 to 42, and d 1 to 42, serum GSH-Px activity, and mRNA expression of jejunal CLDN2 and hepatic ras of broilers (P < 0.05). In contrast with MYCO group, the addition of YPS increased BW, ADFI, and ADG, the serum GSH-Px activity (14.31%-46.92%), mRNA levels of jejunal CLDN2 (94.39%-103.02%), decreased F/G, and mRNA levels of hepatic ras (57.83%-63.62%) of broilers (P < 0.05). In conclusion, dietary supplements with YPS protected broilers from mixed mycotoxins toxicities meanwhile keeping normal performance of broilers, presumably via reducing intestinal oxidative stress, protecting intestinal structural integrity, and improving hepatic metabolic enzymes to minimize the AFB1 residue in the liver and enhance the performance of broilers.

Microbial gasdermins: More than a billion years of pyroptotic-like cell death

In the recent past, the concept of immunity has been extended to eukaryotic and prokaryotic microorganisms, like fungi and bacteria. The latest findings have drawn remarkable evolutionary parallels between metazoan and microbial defense-related genes, unveiling a growing number of shared transkingdom components of immune systems. One such component is the gasdermin family of pore-forming proteins - executioners of a highly inflammatory immune cell death program in mammals, termed pyroptosis. Pyroptotic cell death limits the spread of intracellular pathogens by eliminating infected cells and coordinates the broader inflammatory response to infection. The microbial gasdermins have similarly been implicated in defense-related cell death reactions in fungi, bacteria and archaea. Moreover, the discovery of the molecular regulators of gasdermin cytotoxicity in fungi and bacteria, has established additional evolutionary links to mammalian pyroptotic pathways. Here, we focus on the gasdermin proteins in microorganisms and their role in organismal defense and provide perspective on this remarkable case study in comparative immunology.

Curcumin in cancer therapy: Exploring molecular mechanisms and overcoming clinical challenges

Cancer poses a significant global health burden, necessitating the widespread use of chemotherapy and radiotherapy as conventional frontline interventions. Although targeted therapy and immunotherapy have shown remarkable advancements, the challenges of resistance development and severe side effects persist in cancer treatment. Consequently, researchers have actively sought more effective alternatives with improved safety profiles. In recent years, curcumin, a natural polyphenolic phytoalexin, has garnered considerable attention due to its broad spectrum of biological effects. This concise review provides valuable insights into the role of curcumin in cancer therapy, with a focus on elucidating its molecular mechanisms in inducing programmed cell death of tumor cells and suppressing tumor cell metastasis potential. Additionally, we discuss the challenges associated with the clinical application of curcumin and explore current endeavors aimed at overcoming these limitations. By shedding light on the promising potential of curcumin, this review contributes to the advancement of cancer treatment strategies.

Apoptotic signaling clears engineered Salmonella in an organ-specific manner

Pyroptosis and apoptosis are two forms of regulated cell death that can defend against intracellular infection. Although pyroptosis and apoptosis have distinct signaling pathways, when a cell fails to complete pyroptosis, backup pathways will initiate apoptosis. Here, we investigated the utility of apoptosis compared to pyroptosis in defense against an intracellular bacterial infection. We previously engineered Salmonella enterica serovar Typhimurium to persistently express flagellin, and thereby activate NLRC4 during systemic infection in mice. The resulting pyroptosis clears this flagellin-engineered strain. We now show that infection of caspase-1 or gasdermin D deficient macrophages by this flagellin-engineered S. Typhimurium induces apoptosis in vitro. Additionally, we also now engineer S. Typhimurium to translocate the pro-apoptotic BH3 domain of BID, which also triggers apoptosis in macrophages in vitro. In both engineered strains, apoptosis occurred somewhat slower than pyroptosis. During mouse infection, the apoptotic pathway successfully cleared these engineered S. Typhimurium from the intestinal niche, but failed to clear the bacteria in the myeloid niche in the spleen or lymph nodes. In contrast, the pyroptotic pathway was beneficial in defense of both niches. In order to clear an infection, distinct cell types may have specific tasks that they must complete before they die. In some cells, either apoptotic or pyroptotic signaling may initiate the same tasks, whereas in other cell types these modes of cell death may lead to different tasks that may not be identical in defense against infection. We recently suggested that such diverse tasks can be considered as different cellular 'bucket lists' to be accomplished before a cell dies.

A multiplex blood-based assay targeting DNA methylation in PBMCs enables early detection of breast cancer

The immune system can monitor tumor development, and DNA methylation is involved in the body's immune response to tumors. In this work, we investigate whether DNA methylation alterations in peripheral blood mononuclear cells (PBMCs) could be used as markers for early detection of breast cancer (BC) from the perspective of tumor immune alterations. We identify four BC-specific methylation markers by combining Infinium 850 K BeadChips, pyrosequencing and targeted bisulfite sequencing. Based on the four methylation markers in PBMCs of BC, we develop an efficient and convenient multiplex methylation-specific quantitative PCR assay for the detection of BC and validate its diagnostic performance in a multicenter cohort. This assay was able to distinguish early-stage BC patients from normal controls, with an AUC of 0.940, sensitivity of 93.2%, and specificity of 90.4%. More importantly, this assay outperformed existing clinical diagnostic methods, especially in the detection of early-stage and minimal tumors.

Circulating Plasma miR-122 and miR-583 Levels Are Involved in Chronic Hepatitis B Virus Pathogenesis and Serve As Novel Diagnostic Biomarkers

Background: MicroRNAs regulate many biological processes and are involved in the pathogenesis of many diseases including chronic hepatitis B (CHB). Moreover, besides investigation of their roles in hepatitis B virus (HBV) infection, a noninvasive, sensitive, and specific biomarker is essential in the diagnosis of liver diseases. This study was designed to evaluate the role of miR-122, miR-583, and miR-24 in the pathogenesis of CHB both in active chronic hepatitis (ACH) patients and in inactive carriers (IC). Materials and Methods: Plasma samples and all relevant clinical features were collected from 43 patients with CHB (28 ACH and 15 IC) and 43 healthy controls. Quantitative real-time PCR was performed to detect the plasma levels of miR-122, miR-583, and miR-24. Results: Results show miR-122 (p = 0.0001) and miR-583 (p = 0.006) but not miR-24 (p = 0.65) were upregulated in patients with CHB versus the control group. Interestingly, there was a significant increase in the plasma expression of miR-583 in IC versus ACH. Moreover, receiver operating characteristic curve analysis determined plasma levels of miR-122 (area under the ROC curve [AUC] = 0.89, p < 0.0001, sensitivity: 100%, specificity: 62.5%) and miR-583 (AUC = 0.71, p = 0.0007, sensitivity: 90%, specificity: 47.62%) as sensitive biomarkers to discriminate CHB patients from controls. Conclusion: Our data showed an increase in the plasma levels of miR-583 in IC versus ACH patients. Moreover, we demonstrated that miR-122 and miR-583 may serve as potential biomarkers for CHB diagnosis and activity.

Marine Meroterpenoids Isolated from Gongolaria abies-marina Induce Programmed Cell Death in Naegleria fowleri

Naegleria fowleri is the causative agent of a central nervous system affecting disease called primary amoebic meningoencephalitis. It is a fulminant disease with a rapid progression that affects mainly children and young adults who report previous water exposure. Current treatment options are not totally effective and involve several side effects. In this work, six meroterpenoids isolated from the brown algae Gongolaria abies-marina were evaluated against N. fowleri. Gongolarone B (1), 6Z-1'-methoxyamentadione (2), and 1'-methoxyamentadione (3) were the most active molecules against N. fowleri with IC₅₀ values between 13.27 ± 0.96 µM and 21.92 ± 1.60 µM. However, cystomexicone B (6) was the molecule with the highest selectivity index (>8.5). Moreover, all these compounds induced different cellular events compatible with the apoptosis-like PCD process, such as chromatin condensation, damages at the mitochondrial level, cell membrane disruption, and production of reactive oxygen species (ROS). Therefore, G. abies-marina could be considered as a promising source of active molecules to treat the N. fowleri infections.

Deciphering a cell death-associated signature for predicting prognosis and response to immunotherapy in lung squamous cell carcinoma

BACKGROUND

Lung squamous cell carcinoma (LUSC) is a subtype of non-small cell carcinoma, accounting for about 30% of all lung cancers. Yet, the evaluation of prognostic outcome and therapy response of patients with LUSC remains to be resolved. This study aimed to explore the prognostic value of cell death pathways and develop a cell death-associated signature for predicting prognosis and guiding treatment in LUSC.

METHODS

Transcriptome profiles and corresponding clinical information of LUSC patients were gathered from The Cancer Genome Atlas (TCGA-LUSC, n = 493) and Gene Expression Omnibus database (GSE74777, n = 107). The cell death-related genes including autophagy (n = 348), apoptosis (n = 163), and necrosis (n = 166) were retrieved from the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology databases. In the training cohort (TCGA-LUSC), LASSO Cox regression was used to construct four prognostic signatures of respective autophagy, apoptosis, and necrosis pathway and genes of three pathways. After comparing the four signatures, the cell death index (CDI), the signature of combined genes, was further validated in the GSE74777 dataset. We also investigated the clinical significance of the CDI signature in predicting the immunotherapeutic response of LUSC patients.

RESULTS

The CDI signature was significantly associated with the overall survival of LUSC patients in the training cohort (HR, 2.13; 95% CI, 1.62‒2.82; P < 0.001) and in the validation cohort (HR, 1.94; 95% CI, 1.01‒3.72; P = 0.04). The differentially expressed genes between the high- and low-risk groups contained cell death-associated cytokines and were enriched in immune-associated pathways. We also found a higher infiltration of naive CD4⁺ T cells, monocytes, activated dendritic cells, neutrophils, and lower infiltration of plasma cells and resting memory CD4⁺ T cells in the high-risk group. Tumor stemness indices, mRNAsi and mDNAsi, were both negatively correlated with the risk score of the CDI. Moreover, LUSC patients in the low-risk group are more likely to respond to immunotherapy than those in the high-risk group (P = 0.002).

CONCLUSIONS

This study revealed a reliable cell death-associated signature (CDI) that closely correlated with prognosis and the tumor microenvironment in LUSC, which may assist in predicting the prognosis and response to immunotherapy for patients with LUSC.

Emergence of the fungal immune system

Investigation of fungal biology has been frequently motivated by the fact that many fungal species are important plant and animal pathogens. Such efforts have contributed significantly toward our understanding of fungal pathogenic lifestyles (virulence factors and strategies) and the interplay with host immune systems. In parallel, work on fungal allorecognition systems leading to the characterization of fungal regulated cell death determinants and pathways, has been instrumental for the emergent concept of fungal immunity. The uncovered evolutionary trans-kingdom parallels between fungal regulated cell death pathways and innate immune systems incite us to reflect further on the concept of a fungal immune system. Here, I briefly review key findings that have shaped the fungal immunity paradigm, providing a perspective on what I consider its most glaring knowledge gaps. Undertaking to fill such gaps would establish firmly the fungal immune system inside the broader field of comparative immunology.

PANoptosis-based molecular subtyping and HPAN-index predicts therapeutic response and survival in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is a highly prevalent and fatal cancer. The role of PANoptosis, a novel form of programmed cell death, in HCC is yet to be fully understood. This study focuses on identifying and analyzing PANoptosis-associated differentially expressed genes in HCC (HPAN_DEGs), aiming to enhance our understanding of HCC pathogenesis and potential treatment strategies.

Methods

We analyzed HCC differentially expressed genes from TCGA and IGCG databases and mapped them to the PANoptosis gene set, identifying 69 HPAN_DEGs. These genes underwent enrichment analyses, and consensus clustering analysis was used to determine three distinct HCC subgroups based on their expression profiles. The immune characteristics and mutation landscape of these subgroups were evaluated, and drug sensitivity was predicted using the HPAN-index and relevant databases.

Results

The HPAN_DEGs were mainly enriched in pathways associated with the cell cycle, DNA damage, Drug metabolism, Cytokines, and Immune receptors. We identified three HCC subtypes (Cluster_1, SFN+PDK4-; Cluster_2, SFN-PDK4+; Cluster_3, SFN/PDK4 intermediate expression) based on the expression profiles of the 69 HPAN_DEGs. These subtypes exhibited distinct clinical outcomes, immune characteristics, and mutation landscapes. The HPAN-index, generated by machine learning using the expression levels of 69 HPAN_DEGs, was identified as an independent prognostic factor for HCC. Moreover, the high HPAN-index group exhibited a high response to immunotherapy, while the low HPAN-index group showed sensitivity to small molecule targeted drugs. Notably, we observed that the YWHAB gene plays a significant role in Sorafenib resistance.

Conclusion

This study identified 69 HPAN_DEGs crucial to tumor growth, immune infiltration, and drug resistance in HCC. Additionally, we discovered three distinct HCC subtypes and constructed an HPAN-index to predict immunotherapeutic response and drug sensitivity. Our findings underscore the role of YWHAB in Sorafenib resistance, presenting valuable insights for personalized therapeutic strategy development in HCC.

Emerging evidence for adapting radiotherapy to immunotherapy

Immunotherapy has revolutionized the clinical management of many malignancies but is infrequently associated with durable objective responses when used as a standalone treatment approach, calling for the development of combinatorial regimens with superior efficacy and acceptable toxicity. Radiotherapy, the most commonly used oncological treatment, has attracted considerable attention as a combination partner for immunotherapy owing to its well-known and predictable safety profile, widespread clinical availability, and potential for immunostimulatory effects. However, numerous randomized clinical trials investigating radiotherapy-immunotherapy combinations have failed to demonstrate a therapeutic benefit compared with either modality alone. Such a lack of interaction might reflect suboptimal study design, choice of end points and/or administration of radiotherapy according to standard schedules and target volumes. Indeed, radiotherapy has empirically evolved towards radiation doses and fields that enable maximal cancer cell killing with manageable toxicity to healthy tissues, without much consideration of potential radiation-induced immunostimulatory effects. Herein, we propose the concept that successful radiotherapy-immunotherapy combinations might require modifications of standard radiotherapy regimens and target volumes to optimally sustain immune fitness and enhance the antitumour immune response in support of meaningful clinical benefits.

Caffeic acid, but not ferulic acid, inhibits macrophage pyroptosis by directly blocking gasdermin D activation

Regulated pyroptosis is critical for pathogen elimination by inducing infected cell rupture and pro-inflammatory cytokines secretion, while overwhelmed pyroptosis contributes to organ dysfunction and pathological inflammatory response. Caffeic acid (CA) and ferulic acid (FA) are both well-known antioxidant and anti-inflammatory phenolic acids, which resemble in chemical structure. Here we found that CA, but not FA, protects macrophages from both Nigericin-induced canonical and cytosolic lipopolysaccharide (LPS)-induced non-canonical pyroptosis and alleviates LPS-induced mice sepsis. It significantly improved the survival of pyroptotic cells and LPS-challenged mice and blocked proinflammatory cytokine secretion. The anti-pyroptotic effect of CA is independent of its regulations in cellular lipid peroxidation, mitochondrial function, or pyroptosis-associated gene transcription. Instead, CA arrests pyroptosis by directly associating with gasdermin D (GSDMD) and blocking its processing, resulting in reduced N-GSDMD pore construction and less cellular content release. In LPS-induced septic mice, CA inhibits GSDMD activation in peritoneal macrophages and reduces the serum levels of interleukin-1β and tumor necrosis factor-α as the known pyroptosis inhibitors, disulfiram and dimethyl fumarate. Collectively, these findings suggest that CA inhibits pyroptosis by targeting GSDMD and is a potential candidate for curbing the pyroptosis-associated disease.