NINJ1 mediates inflammatory cell death, PANoptosis, and lethality during infection conditions and heat stress

Uncovering NINJ1 in SLE: Biomarker potential for renal and hematologic manifestations

OBJECTIVE

Systemic lupus erythematosus (SLE) is a complex autoimmune disease, with an unclear etiology. This study investigated the clinical relevance of serum NINJ1 levels in SLE and evaluated its potential as a biomarker.

METHODS

Serum NINJ1 levels were measured in 99 newly diagnosed SLE patients and 43 healthy controls. Associations with clinical features, inflammatory markers, and autoantibodies were analyzed. ROC curve analysis was performed for diagnostic evaluation.

RESULTS

Serum NINJ1 levels were significantly higher in SLE patients (p < 0.0001) and further elevated in those with lupus nephritis (LN) and thrombocytopenia. Positive correlations with proteinuria, CRP, and NLR were found. ROC analysis showed good diagnostic performance (AUC = 0.83).

CONCLUSION

Serum NINJ1 is a promising biomarker for SLE, particularly for identifying LN and thrombocytopenia, and may aid in disease stratification and monitoring.

Ferroptosis-activating metabolite acrolein antagonizes necroptosis and anti-cancer therapeutics

Dysregulated cell death leading to uncontrolled cell proliferation is a hallmark of cancer. Chemotherapy-induced cell death is critical for the success of cancer treatment but this process is impaired by metabolic byproducts. How these byproducts interfere with anti-cancer therapy is unclear. Here, we show that the metabolic byproduct acrolein derived from polyamines, tobacco smoke or fuel combustion, induces ferroptosis independently of ZBP1, while suppressing necroptosis in cancer cells by inhibiting the oligomerization of the necroptosis effector MLKL. Loss of the enzyme SAT1, which contributes to intracellular acrolein production, sensitizes cells to necroptosis. In mice, administration of an acrolein-trapping agent relieves necroptosis blockade and enhances the anti-tumor efficacy of the chemotherapeutic drug cyclophosphamide. Human patients with cancer coupled with a higher cell death activity but a lower expression of genes controlling polyamine metabolism exhibit improved survival. These findings highlight that the removal of metabolic byproducts improves the success of certain chemotherapies.

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

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

Di-butyl phthalate induces apoptosis in Ctenopharyngodon idellus kidney cells through oxidative stress injury

Di-butyl phthalate (DBP) is a major type of phthalate (PAE) contaminant widely used as a plasticizer. Its environmental presence poses threat to humans and aquatic organisms. In this study, Ctenopharyngodon idellus kidney (CIK) cell model was exposed to 100 μM DBP to investigate its effects. Apoptosis was assessed using acridine orange/ethidium bromide staining, flow cytometry, and fluorescein isothiocyanate/propidium iodide labeling. DBP exposure increased the percentage of apoptotic cells. Activities of antioxidant enzymes, superoxide dismutase, total antioxidant activity, glutathione peroxidase, and catalase were inhibited by DBP, whereas the levels of peroxide products were increased. Heat shock proteins were upregulated as a defense mechanism against DBP-induced stress. Further analysis revealed that the Pi3k/Akt pathway, which regulates physical processes to protect cell function, was suppressed by DBP exposure. Reverse transcription-quantitative PCR and western blotting revealed that DBP inhibited Pi3k/Akt signaling while apoptosis gene expression was increased. Notably, these effects of heat shock proteins and Pi3k/Akt, were reversed by N-acetylcysteine. In conclusion, DBP accelerates apoptosis of CIK cells by inhibiting the Pi3k/Akt pathway and anti-oxidative enzyme activities, promoting reactive oxygen species accumulation and enhancing peroxide product generation. These findings highlight the cytotoxic effects of DBP and underscore the need for further research. Our results provide a foundation for further study.

In-situ Sprayed platelet-derived small extracellular vesicles for the skin flap survival by reducing PANoptosis

Necrosis at the distal end of random skin flaps remains a significant challenge, limiting the clinical application of these flaps in plastic and reconstructive surgery. Inhibiting ischemia/reperfusion (I/R) injury and promoting the formation of neovascular networks are critical preventive strategies. Platelet-derived small extracellular vesicles (PL-sEV) are nanocarriers of growth factors that provide an alternative to clinically used platelet-rich plasma and platelet lysates, offering higher growth factor concentrations and lower immunogenicity. In this study, PANoptosis, a distinct form of inflammatory cell death, was fully characterized in a random skin flap model. Subcutaneous injection of PL-sEV improved ischemic skin flap survival by enhancing blood perfusion and reducing PANoptosis levels. In vitro, PL-sEV inhibited oxygen-glucose deprivation/reoxygenation-induced dysfunction in human umbilical vein endothelial cells. Furthermore, PL-sEV was incorporated into a thermosensitive triblock hydrogel, creating a sprayable delivery system (PLEL@PL-sEV). Mechanistic analysis through RNA sequencing indicated that the protective effects of PL-sEV against PANoptosis likely resulted from its anti-inflammatory properties, particularly via suppression of the NF-κB signaling pathway. This novel hydrogel system demonstrated controlled release of PL-sEV and proved effective in improving skin flap transplantation outcomes.

Estradiol Alleviates Elevated Temperature-Induced Damage in Yak Oviductal Epithelial Cells by Maintaining Endoplasmic Reticulum Calcium Homeostasis

BACKGROUND

The oviduct is an organ that participates in multiple critical reproductive processes and provides essential nutritional support while maintaining a specialized microenvironment. It is particularly vulnerable to damage following heat stress-induced hyperthermia. Therefore, mitigating heat-induced damage to oviduct epithelial cells while preserving their physiological integrity under hyperthermia represents a critical therapeutic goal.

OBJECTIVE

This study aims to simulate the cellular damage state in yak oviduct epithelial cells (YOECs) under thermal challenge by increasing the incubation temperature of cultured cells, while observing changes in cellular injury upon supplementation with 17β-estradiol (E2), in order to explore the underlying cellular regulatory mechanisms involved.

RESULTS

After 48 h of exposure to 41 °C, YOECs exhibited elevated HSP70 and HSP90 protein expression levels, reduced OVGP1 protein expression, and increased apoptotic cells. Compared to the 41 °C group, the E2 + 41 °C group displayed decreased HSP70 protein levels, increased OVGP1 protein expression, and reduced apoptotic cell numbers. Additionally, changes in endoplasmic reticulum calcium ion (ER-Ca2+) distribution and fluorescence intensity variations in ER-Ca2+ regulatory proteins SERCA and IP3R3 were analyzed in the 37 °C, 41 °C, and E2 + 41 °C groups. The ER-Ca2+ distribution pattern in the E2 + 41 °C group remained similar to that of the 37 °C group. However, the fluorescence intensity levels of SERCA and IP3R3 proteins in the E2 + 41 °C group did not recover to levels comparable to the 37 °C group.

CONCLUSION

These findings suggest that E2 may mitigate thermal challenge-induced cellular damage in YOECs by maintaining ER-Ca2+ homeostasis, thereby preserving cellular functionality under elevated temperatures.

NINJ1 and MMP9: potential biomarkers for intracranial atherosclerosis plaque vulnerability

Background and objective

To utilize high-resolution vessel wall imaging (HR-VWI) to identify the characteristic features of culprit plaques in intracranial atherosclerotic stenosis (ICAS) vessels and evaluate the predictive value of serum nerve injury-induced protein 1 (NINJ1) and matrix metalloproteinase 9 (MMP9) for the vulnerability of intracranial atherosclerotic plaques.

Methods

This study included symptomatic intracranial atherosclerotic stenosis (sICAS) patients who underwent high-resolution vessel wall imaging (HR-VWI) and healthy individuals. Patients were divided into non-enhancement/enhancement, moderate/severe stenosis, and positive/negative remodeling groups. Multivariate logistic regression and receiver operating characteristic (ROC) curve analyses were used to evaluate the predictive value of NINJ1 and MMP9 for plaque enhancement, severe stenosis, and positive remodeling.

Results

NINJ1 and MMP9 levels were higher in the plaque enhancement group compared to the non-enhancement group (107.04 vs. 93.49, p = 0.001; 245.35 vs. 227.16, p = 0.002) and were independent risk factors for plaque enhancement (OR: 1.036, p = 0.003; OR: 1.022, p = 0.008). The area under the curve (AUC) for predicting plaque enhancement by NINJ1 and MMP9 were 0.676 and 0.667, respectively, and the combined AUC was 0.740. In the severe stenosis group, NINJ1 and MMP9 levels were also higher than in the moderate stenosis group (106.28 vs. 94.54, p = 0.006; 243.88 vs. 229.38, p = 0.014), with both being independent risk factors (OR: 1.027, p = 0.012; OR: 1.017, p = 0.027). The AUC for predicting severe stenosis by NINJ1 and MMP9 were 0.652 and 0.646, respectively, and the combined AUC was 0.686. For the positive remodeling group, NINJ1 and MMP9 levels were significantly elevated (108.73 vs. 97.27, p = 0.007; 248.36 vs. 230.42, p = 0.002), and both were independent risk factors (OR: 1.026, p = 0.015; OR: 1.023, p = 0.004). The AUC for predicting positive remodeling by NINJ1 and MMP9 were 0.642 and 0.672, respectively, and the combined AUC was 0.722.

Conclusion

NINJ1 and MMP9 can serve as independent predictors factors for intracranial atherosclerotic plaque enhancement, severe stenosis, and positive remodeling. NINJ1 and MMP9 have the potential to be serum biomarkers for the vulnerability of intracranial atherosclerotic plaques.

Innate immune sensor NLRP3 drives PANoptosome formation and PANoptosis

Inflammasomes are multiprotein innate immune complexes formed in response to infections, tissue damage, or cellular stress that promote the maturation and release of IL-1β/IL-18 and are implicated in lytic cell death. The NLRP3 inflammasome is canonically activated by an initial priming event followed by an activation stimulus, leading to rapid cell death that occurs through caspase-1 (CASP1) and gasdermin D (GSDMD) activation, called pyroptosis. CASP1- and GSDMD-deficient cells are protected from the rapid LPS plus ATP-induced pyroptosis. However, innate immune responses physiologically occur over time, extending beyond minutes to hours and days. Therefore, in this study, we assessed lytic cell death beyond the early timepoints. While cells lacking the innate immune sensor NLRP3 were protected from cell death induced by the canonical NLRP3 trigger, LPS priming and ATP stimulation (LPS plus ATP), for extended time, CASP1- and GSDMD-deficient cells started to lyse in a time-dependent manner after 2 h. Nevertheless, robust IL-1β and IL-18 release was still dependent on CASP1 activation. These data suggested that NLRP3 engages an additional innate immune, lytic cell death pathway. Indeed, LPS plus ATP induced the activation of caspases and RIPKs associated with PANoptosis in WT cells, and cells deficient in PANoptosis machinery were protected from cell death for extended times. A PANoptosome complex containing NLRP3, ASC, CASP8, and RIPK3 was observed by microscopy in WT, as well as CASP1- or GSDMD-deficient, cells by 30 min post-stimulation. Overall, these findings highlight the central role of NLRP3 as a PANoptosome sensor. Given the physiological role of innate immune cell death, PANoptosis, in health and disease, our study emphasizes the importance of a comprehensive understanding of PANoptosomes, and their components, as therapeutic targets.

NINJ1: A NOVEL SEPSIS SEVERITY AND MORTALITY BIOMARKER

ABSTRACT

Background : Multiple cell death modalities are implicated in sepsis pathobiology. However, the clinical relevance of NINJ1, a key mediator of plasma membrane rupture during lytic cell death, in sepsis progression and outcomes has remained poorly explored. Methods: Circulating NINJ1 levels were measured in 116 septic intensive care unit (ICU) patients, 16 nonseptic ICU controls, and 16 healthy controls. Comparative analysis of serum NINJ1 across these groups was performed. Correlations between NINJ1 and clinical disease severity scores (Sequential Organ Failure Assessment [SOFA], Acute Physiology and Chronic Health Evaluation [APACHE II]) as well as laboratory parameters were examined in the sepsis cohort. Furthermore, we assessed the prognostic performance of NINJ1 for predicting 28-day mortality in septic patients using receiver operating characteristic (ROC) analyses. Results: Circulating NINJ1 levels were elevated in septic patients and positively correlated with sepsis severity scores. NINJ1 also showed positive correlations with liver injury markers (aspartate transaminase/alanine aminotransferase) and coagulation parameters (D-dimer, activated partial thromboplastin time, prothrombin time, thrombin time) in sepsis. Further analysis using the International Society on Thrombosis and Hemostasis overt disseminated intravascular coagulation scoring system revealed an association between NINJ1 and sepsis-induced coagulopathy. ROC analysis demonstrated that NINJ1 outperformed traditional inflammatory biomarkers procalcitonin and C-reactive protein in predicting 28-day sepsis mortality, although its prognostic accuracy was lower than SOFA and APACHE II scores. Combining NINJ1 with SOFA improved mortality prediction from an area under the curve of 0.6843 to 0.773. Conclusions: Circulating NINJ1 serves as a novel sepsis biomarker indicative of disease severity, coagulopathy and mortality risk, and its integration with SOFA and APACHE II scores substantially enhances prognostic risk stratification. These findings highlight the prospective clinical utility of NINJ1 for sepsis prognostication and monitoring, warranting further validation studies to facilitate implementation.

Unravelling the Role of PANoptosis in Liver Diseases: Mechanisms and Therapeutic Implications

PANoptosis is a multimodal form of cell death that involves inflammatory, apoptotic, and necroptotic pathways, playing a key role in the development of liver diseases. This article first outlines the definition and characteristics of PANoptosis, and then explores its mechanisms of action in different types of liver diseases, including acute liver injury, liver failure, metabolic dysfunction-associated fatty liver disease, and hepatocellular carcinoma. Furthermore, this article analyses the molecular regulatory network of PANoptosis and potential therapeutic targets. Finally, this article summarises the current research on PANoptosis in liver diseases and future research directions, and it reviews the role of the emerging cell death mechanism of PANoptosis in liver diseases.

Cell death in acute lung injury: caspase-regulated apoptosis, pyroptosis, necroptosis, and PANoptosis

There has been abundant research on the variety of programmed cell death pathways. Apoptosis, pyroptosis, and necroptosis under the action of the caspase family are essential for the innate immune response. Caspases are classified into inflammatory caspase-1/4/5/11, apoptotic caspase-3/6/7, and caspase-2/8/9/10. Although necroptosis is not caspase-dependent to transmit cell death signals, it can cross-link with pyroptosis and apoptosis signals under the regulation of caspase-8. An increasing number of studies have reiterated the involvement of the caspase family in acute lung injuries caused by bacterial and viral infections, blood transfusion, and ventilation, which is influenced by noxious stimuli that activate or inhibit caspase engagement pathways, leading to subsequent lung injury. This article reviews the role of caspases implicated in diverse programmed cell death mechanisms in acute lung injury and the status of research on relevant inhibitors against essential target proteins of the described cell death mechanisms. The findings of this review may help in delineating novel therapeutic targets for acute lung injury.

The critical role of the ZBP1-NINJ1 axis and IRF1/IRF9 in ethanol-induced cell death, PANoptosis, and alcohol-associated liver disease

Innate immunity provides the critical first line of defense against infection and sterile triggers. Cell death is a key component of the innate immune response to clear pathogens, but excessive or aberrant cell death can induce inflammation, cytokine storm, and pathology, making it a central molecular mechanism in inflammatory diseases. Alcohol-associated liver disease (ALD) is one such inflammatory disease, but the specific innate immune mechanisms driving pathology in this context remain unclear. Here, by leveraging RNAseq and tissue expression in clinical samples, we identified increased expression of the innate immune sensor Z-DNA binding protein (ZBP1) in patients with ALD. We discovered that ZBP1 expression correlated with ALD progression in patients, and that ethanol induced ZBP1-dependent lytic cell death, PANoptosis, in immune (macrophages, monocytes, Kupffer cells) and non-immune cells (hepatocytes). Mechanistically, the interferon regulatory factors (IRFs) IRF9 and IRF1 upregulated ZBP1 expression, allowing ZBP1 to sense Z-NAs through its Zα2 domain and drive PANoptosis signaling, cell membrane rupture through NINJ1, and DAMP release. Furthermore, the expressions of ZBP1 and NINJ1 were upregulated in both liver and serum samples from patients with ALD. In mouse models of chronic and acute ALD, ZBP1-deficient mice were significantly protected from disease pathology and liver damage. Overall, our findings establish the critical role of the ZBP1-NINJ1 axis regulated by IRFs in driving inflammatory cell death, PANoptosis, in liver cells, suggesting that targeting these molecules will have therapeutic potential in ALD and other inflammatory conditions.

Near-Infrared Nanothermometer Reveals Temperature Discrepancy between Organs and Body Surface for Heatstroke Prevention

Organ temperatures often vary significantly from body surface temperatures during heatstroke, leading to acute organ failure, although body temperature is continuously controlled. However, the exact temperature discrepancy between them remains unclear due to a lack of noninvasive techniques for real-time monitoring of organ temperature fluctuations. Herein, we developed a near-infrared emissive nanothermometer by codoping Nd3+ and Yb3+ to produce two distinct emissions at 980 and 1330 nm under 808 nm excitation. These emissions demonstrated differential responses to temperature variations, enabling the construction of a ratiometric nanoprobe for accurate temperature detection. Notably, the nanoprobe rapidly accumulated in mouse liver after intravenous injection, revealing that liver showed consistently higher temperature than rectum by approximately 1.5 °C. Moreover, liver injury was found to begin at a rectal temperature of 42 °C, rather than the 43 °C conventionally used in heatstroke models. These findings introduce a robust nanothermometer for accurately understanding the pathological progression of heat-related illnesses.

TAK1 at the crossroads of multiple regulated cell death pathways: from molecular mechanisms to human diseases

Regulated cell death (RCD), the form of cell death that can be genetically controlled by multiple signaling pathways, plays an important role in organogenesis, tissue remodeling, and maintenance of organism homeostasis and is closely associated with various human diseases. Transforming growth factor‐beta‐activated kinase 1 (TAK1) is a member of the serine/threonine protein kinase family, which can respond to different internal and external stimuli and participate in inflammatory and immune responses. Emerging evidence suggests that TAK1 is an important regulator at the crossroad of multiple RCD pathways, including apoptosis, necroptosis, pyroptosis, and PANoptosis. The regulation of TAK1 affects disease progression through multiple signaling pathways, and therapeutic strategies targeting TAK1 have been proposed for inflammatory diseases, central nervous system diseases, and cancers. In this review, we provide an overview of the downstream signaling pathways regulated by TAK1 and its binding proteins. Their critical regulatory roles in different forms of cell death are also summarized. In addition, we discuss the potential of targeting TAK1 in the treatment of human diseases, with a specific focus on neurological disorders and cancer.

Omega-3 PUFAs improve cognitive function in heat-stressed mice by enhancing autophagy via inhibition of the phosphorylation of the PI3K-Akt-mTOR pathway

The adverse effects of elevated temperatures on human health are becoming progressively severe. This research established a mouse model of cognitive dysfunction induced by heat stress to examine the impact of omega-3 PUFAs on the cognitive capabilities of heat-stressed mice. The study also aimed to elucidate the role and potential mechanisms of autophagy regulation in cognitive enhancement through omega-3 PUFAs interventions. Administration of omega-3 PUFAs ameliorated cognitive deficits in heat-stressed mice and increased brain concentrations of these fatty acids. Notably, omega-3 PUFAs significantly protected hippocampal neurons' morphology, quantity, and synaptic architecture in heat-stressed mice. Additionally, omega-3 PUFAs intake reduced the prevalence of damaged mitochondria in the hippocampus and mitigated oxidative harm. Further investigation revealed that heat stress induces autophagy. However, the autophagic process becomes dysfunctional, leading to impaired autophagic activity. Omega-3 PUFAs supplementation markedly augmented hippocampal autophagy in the heat-stressed mice. Moreover, heat stress upregulated the phosphorylation of the PI3K-Akt-mTOR pathway in both the mouse hippocampus and HT22 cells. In contrast, omega-3 PUFAs intake significantly diminished the phosphorylation levels within this pathway, alleviating the autophagic fusion barrier imposed by heat stress and promoting autophagic flux. The findings suggest that omega-3 PUFAs supplementation during heat stress may bolster autophagic function by inhibiting the phosphorylation of the PI3K-Akt-mTOR pathway. This modulation reduces structural and oxidative stress damage, ultimately enhancing cognitive function in mice subjected to heat stress.

Targeting GSDMD JX06 inhibits PANoptosis and multiple organ injury

Multiple organ dysfunction syndrome (MODS) is the major cause of mortality of patients in intensive care units. The elusive mechanisms of tissue damage in MODS and limited therapeutic options encourage us to seek effective therapies to MODS. PANoptosis has recently been proven to be the key player in both heat stress and sepsis-mediated MODS. Therefore, we initially investigated the role of gasdermin D (GSDMD) in heat stress and sepsis-induced MODS. We found that GSDMD deficiency attenuates heat stress or sepsis mediated cell death, tissue inflammation and severe multiple organ injury (MOI). Next, we screened out and proved that JX06 effectively inhibited GSDMD-NT mediated cell death, by covalently modifying the Cys39/192 residue in GSDMD, inhibiting the accumulation of GSDMD-NT and pore formation in cell membrane. In vivo, JX06 administration attenuated heat stress and sepsis-mediated cell death, inflammation, MODS and animal mortality via suppressing GSDMD-mediated PANoptosis. Overall, our results indicated that GSDMD is critical for MODS by executing PANoptosis; administrating its inhibitor, JX06, effectively suppresses MODS by inhibiting PANoptosis, and suggesting that JX06 would be an effective drug candidate for MODS and related death.

Multifaceted roles of ninjurin1 in immunity, cell death, and disease

Ninjurin1 (NINJ1) is initially identified as a nerve injury-induced adhesion molecule that facilitates axon growth. It is initially characterized to promote nerve regeneration and mediate the transendothelial transport of monocytes/macrophages associated with neuroinflammation. Recent evidence indicates that NINJ1 mediates plasma membrane rupture (PMR) in lytic cell death. The absence or inhibition of NINJ1 can delay PMR, thereby mitigating the spread of inflammation resulting from cell lysis and preventing the progression of various cell death-related pathologies, suggesting a conserved regulatory mechanism across these processes. Further research elucidated the structural basis and mechanism of NINJ1-mediated PMR. Although the role of NINJ1 in PMR is established, the identity of its activating factors and its implications in diseases remain to be fully explored. This review synthesizes current knowledge regarding the structural basis and mechanism of NINJ1-mediated PMR and discusses its significance and therapeutic targeting potential in inflammatory diseases, neurological disorders, cancer, and vascular injuries.

Coexposure to ambient air pollution and temperature and its associations with birth outcomes in women undergoing assisted reproductive technology in Fujian, China: A retrospective cohort study

BACKGROUND

The interactions between pollutants and temperature coexposure, the mixing effects and their potential mechanisms remain uncertain.

METHODS

This retrospective cohort study included 11,766 women with infertility who received treatment at Fujian Hospital between 2015 and 2024. The daily mean concentrations of the six pollutants and the relative humidity and temperature data were acquired from the Fujian region. Data on genes were obtained from the Comparative Toxicogenomics Database.

RESULTS

O3 (aOR=0.80, 95 % CI=0.725--0.891) and temperature (aOR=0.936, 95 % CI=0.916--0.957) were negatively correlated with live birth rates. Moreover, PM10 (aOR=1.135, 95 % CI=1.028--1.252) and PM2.5 (aOR=1.146, 95 % CI=1.03--1.274) were positively associated with preterm birth. Among the effects on live births, PM2.5, PM10, NO2, CO, and SO2 had significant synergistic effects with temperature; in addition, O3 had significant antagonistic effects with temperature. A notable trend toward declining live birth rates with elevated concentrations of mixed pollutants was observed. Different infertility patients have different sensitivities to coexposure. Gene enrichment and cell experiments are associated mainly with cellular life activities.

CONCLUSIONS

Individual effects, interactions, and mixed effects between temperature and air pollutants and birth outcomes persist when air pollutant levels are relatively low. AAP may trigger miscarriage through cytotoxic effects.

Autoinhibition of dimeric NINJ1 prevents plasma membrane rupture

Lytic cell death culminates in plasma membrane rupture, which releases large intracellular molecules to augment the inflammatory response. Plasma membrane rupture is mediated by the effector membrane protein ninjurin-1 (NINJ1)1, which polymerizes and ruptures the membrane via its hydrophilic face1-4. How NINJ1 is restrained under steady-state conditions to ensure cell survival remains unknown. Here we describe the molecular underpinnings of NINJ1 inhibition. Using cryogenic electron microscopy, we determined the structure of inactive-state mouse NINJ1 bound to the newly developed nanobody Nb538. Inactive NINJ1 forms a face-to-face homodimer by adopting a three-helix conformation with unkinked transmembrane helix 1 (TM1), in contrast to the four-helix TM1-kinked active conformation2-4. Accordingly, endogenous NINJ1 from primary macrophages is a dimer under steady-state conditions. Inactive dimers sequester the membrane rupture-inducing hydrophilic face of NINJ1 and occlude the binding site for kinked TM1 from neighbouring activated NINJ1 molecules. Mutagenesis studies in cells show that destabilization of inactive face-to-face dimers leads to NINJ1-mediated cell death, whereas stabilization of face-to-face dimers inhibits NINJ1 activity. Moreover, destabilizing mutations prompt spontaneous TM1 kink formation, a hallmark of NINJ1 activation. Collectively, our data demonstrate that dimeric NINJ1 is autoinhibited in trans to prevent unprovoked plasma membrane rupture and cell death.

NINJ1: Bridging lytic cell death and inflammation therapy

NINJ1, a critical transmembrane protein in inflammation, governs diverse biological processes. Recent breakthroughs revealed NINJ1's structural basis for plasma membrane rupture, which is directly linked to lytic cell death. This discussion explores NINJ1's functions, focusing on its pivotal role in lytic cell death regulation and the latest advancements in targeted therapeutic interventions.

Liver Transplantation: A Test of Cellular Physiology, Preservation, and Injury

Liver transplantation has evolved into a mature clinical field, but scarcity of usable organs poses a unique challenge. Expanding the donor pool requires novel approaches for protecting hepatic physiology and cellular homeostasis. Here we define hepatocellular injury during transplantation, with an emphasis on modifiable cell death pathways as future therapeutics.

Classical apoptotic stimulus, staurosporine, induces lytic inflammatory cell death, PANoptosis

Innate immunity is the body's first line of defense against disease, and regulated cell death is a central component of this response that balances pathogen clearance and inflammation. Cell death pathways are generally categorized as non-lytic and lytic. While non-lytic apoptosis has been extensively studied in health and disease, lytic cell death pathways are also increasingly implicated in infectious and inflammatory diseases and cancers. Staurosporine (STS) is a well-known inducer of non-lytic apoptosis. However, in this study, we observed that STS also induces lytic cell death at later timepoints. Using biochemical assessments with genetic knockouts, pharmacological inhibitors, and gene silencing, we identified that STS triggered PANoptosis via the caspase-8/RIPK3 axis, which was mediated by RIPK1. PANoptosis is a lytic, innate immune cell death pathway initiated by innate immune sensors and driven by caspases and RIPKs through PANoptosome complexes. Deletion of caspase-8 and RIPK3, core components of the PANoptosome complex, protected against STS-induced lytic cell death. Overall, our study identifies STS as a time-dependent inducer of lytic cell death, PANoptosis. These findings emphasize the importance of understanding trigger- and time-specific activation of distinct cell death pathways to advance our understanding of the molecular mechanisms of innate immunity and cell death for clinical translation.

Innate immune sensing of cell death in disease and therapeutics

Innate immunity, cell death and inflammation underpin many aspects of health and disease. Upon sensing pathogens, pathogen-associated molecular patterns or damage-associated molecular patterns, the innate immune system activates lytic, inflammatory cell death, such as pyroptosis and PANoptosis. These genetically defined, regulated cell death pathways not only contribute to the host defence against infectious disease, but also promote pathological manifestations leading to cancer and inflammatory diseases. Our understanding of the underlying mechanisms has grown rapidly in recent years. However, how dying cells, cell corpses and their liberated cytokines, chemokines and inflammatory signalling molecules are further sensed by innate immune cells, and their contribution to further amplify inflammation, trigger antigen presentation and activate adaptive immunity, is less clear. Here, we discuss how pattern-recognition and PANoptosome sensors in innate immune cells recognize and respond to cell-death signatures. We also highlight molecular targets of the innate immune response for potential therapeutic development.

Chromatin Regulator SMARCA4 Is Essential for MHV-Induced Inflammatory Cell Death, PANoptosis

The innate immune system serves as the first line of defense against β-coronaviruses (β-CoVs), a family of viruses that includes SARS-CoV-2. Viral sensing via pattern recognition receptors triggers inflammation and cell death, which are essential components of the innate immune response that facilitate viral clearance. However, excessive activation of the innate immune system and inflammatory cell death can result in uncontrolled release of proinflammatory cytokines, resulting in cytokine storm and pathology. PANoptosis, innate immune, inflammatory cell death initiated by innate immune sensors and driven by caspases and RIPKs through PANoptosome complexes, has been implicated in the pathology of viral infections. Therefore, understanding the molecular mechanisms regulating PANoptosis in response to β-CoV infection is critical for identifying new therapeutic targets that can mitigate disease severity. In the current study, we analyzed findings from a cell death-based CRISPR screen with archetypal β-CoV mouse hepatitis virus (MHV) as the trigger to characterize host molecules required for inflammatory cell death. As a result, we identified SMARCA4, a chromatin regulator, as a putative host factor required for PANoptosis in response to MHV. Furthermore, we observed that gRNA-mediated deletion of Smarca4 inhibited MHV-induced PANoptotic cell death in macrophages. These findings have potential translational and clinical implications for the advancement of treatment strategies for β-CoVs and other infections.

Programmed cell death: NINJ1 and mechanisms of plasma membrane rupture

Lytic cell death culminates in cell swelling and plasma membrane rupture (PMR). The cellular contents released, including proteins, metabolites, and nucleic acids, can act as danger signals and induce inflammation. During regulated cell death (RCD), lysis is actively initiated and can be preceded by an initial loss of membrane integrity caused by pore-forming proteins, allowing small molecules and cytokines to exit the cell. A recent seminal discovery showed that ninjurin1 (NINJ1) is the common executioner of PMR downstream of RCD, resulting in the release of large proinflammatory molecules and representing a novel target of cell death-associated lysis. We summarize recent developments in understanding membrane integrity and rupture of the plasma membrane with a focus on NINJ1.

Scutellarin inhibits inflammatory PANoptosis by diminishing mitochondrial ROS generation and blocking PANoptosome formation

PANoptosis is manifested with simultaneous activation of biomarkers for both pyroptotic, apoptotic and necroptotic signaling via the molecular platform PANoptosome and it is involved in pathologies of various inflammatory diseases including hemophagocytic lymphohistiocytosis (HLH). Scutellarin is a flavonoid isolated from herbal Erigeron breviscapus (Vant.) Hand.-Mazz. and has been shown to possess multiple pharmacological effects, but it is unknown whether scutellarin has any effects on PANoptosis and related inflammatory diseases. In this study, we found that scutellarin inhibited cell death in bone marrow-derived macrophages (BMDMs) and J774A.1 cells treated with TGF-β-activated kinase 1 (TAK1) inhibitor 5Z-7-oxozeaenol (OXO) plus lipopolysaccharide (LPS), which has been commonly used to induce PANoptosis. Western blotting showed that scutellarin dose-dependently inhibited the activation biomarkers for pyroptotic (Caspase-1p10 and GSDMD-NT), apoptotic (cleaved Casp3/8/9 and GSDME-NT), and necroptotic (phosphorylated MLKL) signaling. The inhibitory effect of scutellarin was unaffected by NLRP3 or Caspase-1 deletion. Interestingly, scutellarin blocked the assembly of PANoptosome that encompasses ASC, RIPK3, Caspase-8 and ZBP1, suggesting its action on upstream signaling. Consistent with this, scutellarin inhibited mitochondrial damage and mitochondrial reactive oxygen species (mtROS) generation in cells treated with OXO+LPS. Further, mito-TEMPO that can scavenge mtROS significantly inhibited OXO+LPS-induced PANoptotic cell death. In line with the in vitro results, scutellarin markedly alleviated systemic inflammation, multiple organ injury, and activation of PANoptotic biomarkers in mice with HLH. Collectively, our data suggest that scutellarin can inhibit PANoptosis by suppressing mitochondrial damage and mtROS generation and thereby mitigating multiple organ injury in mice with inflammatory disorders.

Implications of inflammatory cell death-PANoptosis in health and disease

Regulated cell death (RCD) pathways, such as pyroptosis, apoptosis, and necroptosis, are essential for maintaining the body's balance, defending against pathogens, and eliminating abnormal cells that could lead to diseases like cancer. Although these pathways operate through distinct mechanisms, recent genetic and pharmacological studies have shown that they can interact and influence each other. The concept of "PANoptosis" has emerged, highlighting the interplay between pyroptosis, apoptosis, and necroptosis, especially during cellular responses to infections. This article provides a concise overview of PANoptosis and its molecular mechanisms, exploring its implications in various diseases. The review focuses on the extensive interactions among different RCD pathways, emphasizing the role of PANoptosis in infections, cytokine storms, inflammatory diseases, and cancer. Understanding PANoptosis is crucial for developing novel treatments for conditions involving infections, sterile inflammations, and cancer.