Caspase-1 Inflammasome Activation Mediates Homocysteine-Induced Pyrop-Apoptosis in Endothelial Cells

NLRP3 promotes radiation-induced brain injury by regulating microglial pyroptosis

PURPOSE

Radiation-induced brain injury, one of the side effects of cranial radiotherapy in tumour patients, usually results in durable and serious cognitive disorders. Microglia are important innate immune-effector cells in the central nervous system. However, the interaction between microglia and neurons in radiation-induced brain injury remains uncharacterised.

METHODS AND MATERIALS

We established a microglia-neuron indirect co-culture model to assess the interaction between them. Microglia exposed to radiation were examined for pyroptosis using lactate dehydrogenase (LDH) release, Annexin V/PI staining, SYTOX staining and western blot. The role of nucleotide-binding oligomerisation domain-like receptor family pyrin domain containing 3 (NLRP3) was investigated in microglia exposed to radiation and in mouse radiation brain injury model through siRNA or inhibitor. Mini-mental state examination and cytokines in blood were performed in 23 patients who had experienced cranial irradiation.

RESULTS

Microglia exerted neurotoxic features after radiation in the co-culture model. NLRP3 was up-regulated in microglia exposed to radiation, and then caspase-1 was activated. Thus, the gasdermin D protein was cleaved, and it triggered pyroptosis in microglia, which released inflammatory cytokines. Meanwhile, treatment with siRNA NLRP3 in vitro and NLRP3 inhibitor in vivo attenuated the damaged neuron cell and cognitive impairment, respectively. What is more, we found that the patients after radiation with higher IL-6 were observed to have a decreased MMSE score.

CONCLUSIONS

These findings indicate that radiation-induced pyroptosis in microglia may promote radiation-induced brain injury via the secretion of neurotoxic cytokines. NLRP3 was evaluated as an important mediator in radiation-induced pyroptosis and a promising therapeutic target for radiation-induced brain injury.

Pyroptosis of Vascular Smooth Muscle Cells as a Potential New Target for Preventing Vascular Diseases

Vascular remodeling is the adaptive response of the vessel wall to physiological and pathophysiological changes, closely linked to vascular diseases. Vascular smooth muscle cells (VSMCs) play a crucial role in this process. Pyroptosis, a form of programmed cell death characterized by excessive release of inflammatory factors, can cause phenotypic transformation of VSMCs, leading to their proliferation, migration, and calcification-all of which accelerate vascular remodeling. Inhibition of VSMC pyroptosis can delay this process. This review summarizes the impact of pyroptosis on VSMCs and the pathogenic role of VSMC pyroptosis in vascular remodeling. We also discuss inhibitors of key proteins in pyroptosis pathways and their effects on VSMC pyroptosis. These findings enhance our understanding of the pathogenesis of vascular remodeling and provide a foundation for the development of novel medications that target the control of VSMC pyroptosis as a potential treatment strategy for vascular diseases.

Low-Shear Stress Promotes Atherosclerosis via Inducing Endothelial Cell Pyroptosis Mediated by IKKε/STAT1/NLRP3 Pathway

Atherosclerosis is initiated by vascular endothelial dysfunction, and low-shear stress (LSS) of blood flow is a key factor leading to endothelial dysfunction. Growing evidence suggests that endothelial cell pyroptosis plays an important role in the development of atherosclerosis. Studies have shown that low-shear stress can induce endothelial cell pyroptosis, but the exact mechanism remains unclear. Our experiments demonstrated that low-shear stress induced endothelial cell pyroptosis and the phosphorylation of IκB kinase ε (IKKε). IKKε knockdown not only significantly attenuated atherosclerosis lesions of aortic arch areas in ApoE-/- mice fed with high cholesterol diets, but also markedly reduced endothelial cell pyroptosis and NLRP3 expression triggered by low-shear stress. Further mechanism studies showed that IKKε promoted the expression of NLRP3 via activating signal transducer and activator of transcription 1 (STAT1) and the subsequent binding of STAT1 to NLRP3 promoter region. These results suggest that low-shear stress plays a pro-atherosclerotic role by promoting endothelial cell pyroptosis through the IKKε/STAT1/NLRP3 pathway, which provides new insights into the formation of atherosclerosis.

Exosomes derived from mesenchymal stem cells attenuate NLRP3-related pyroptosis in autoimmune premature ovarian insufficiency via the NF-κB pathway

RESEARCH QUESTION

What is the effect of exosomes derived from bone marrow mesenchymal stem cells (MSC-Exos) on the pyroptosis and recovery of granulosa cells in autoimmune premature ovarian insufficiency (POI)?

DESIGN

In vitro, KGN cells were exposed to interferon-gamma to simulate immune injury. Samples were collected after a 48 h incubation with MSC-Exos (30 μg/ml). The cell viability, secretion of oestrogen and expression of key molecules in pyroptosis and the nuclear factor kappa B (NF-κB) pathway were tested. In vivo, the BALB/c mouse model of autoimmune POI model induced by zona pellucida glycoprotein 3 was used. Fertility testing and sample collection were applied 4 weeks after the ovarian subcapsular injection of MSC-Exos (150 μg for each ovary). Hormone concentration measurements, follicle counting and pyroptotic pathway analyses were conducted for each group.

RESULTS

In vitro, MSC-Exos significantly promoted the proliferation rate and secretion of oestrogen, while at the same time suppressing apoptosis and pyroptosis. In vivo, exosomal treatment normalized the irregular oestrous cycles, rescued the follicular loss and increased the pregnancy rate and number of offspring in POI mice. Elevated serum concentrations of oestrogen and anti-Müllerian hormone, as well as decreased concentrations of FSH and interleukin-1β, were shown. Furthermore, MSC-Exos down-regulated the expression of the NLRP3/Casp1/GSDMD pathway and inhibited activation of the NF-κB pathway.

CONCLUSIONS

These findings demonstrate for the first time that MSC-Exos exert a significant effect on restoring ovarian function in autoimmune POI in vivo and in vitro by suppressing the NLRP3/Casp1/GSDMD pathway and pyroptosis. The NF-κB pathway may contribute to the regulation of NLRP3-related pyroptosis.

Natural Polymer-Polyphenol Bioadhesive Coacervate with Stable Wet Adhesion, Antibacterial Activity, and On-Demand Detachment

Medical adhesives are emerging as an important clinical tool as adjuvants for sutures and staples in wound closure and healing and in the achievement of hemostasis. However, clinical adhesives combining cytocompatibility, as well as strong and stable adhesion in physiological conditions, are still in demand. Herein, a mussel-inspired strategy is explored to produce adhesive coacervates using tannic acid (TA) and methacrylate pullulan (PUL-MA). TA|PUL-MA coacervates mainly comprise van der Waals forces and hydrophobic interactions. The methacrylic groups in the PUL backbone increase the number of interactions in the adhesives matrix, resulting in enhanced cohesion and adhesion strength (72.7 Jm-2), compared to the non-methacrylated coacervate. The adhesive properties are kept in physiologic-mimetic solutions (72.8 Jm-2) for 72 h. The photopolymerization of TA|PUL-MA enables the on-demand detachment of the adhesive. The poor cytocompatibility associated with the use of phenolic groups is here circumvented by mixing reactive oxygen species-degrading enzyme in the adhesive coacervate. This addition does not hamper the adhesive character of the materials, nor their anti-microbial or hemostatic properties. This affordable and straightforward methodology, together with the tailorable adhesivity even in wet environments, high cytocompatibility, and anti-bacterial activity, enables foresee TA|PUL-MA as a promising ready-to-use bioadhesive for biomedical applications.

The mitochondrial signature of cultured endothelial cells in sepsis: Identifying potential targets for treatment

Sepsis is the most common cause of death from infection in the world. Unfortunately, there is no specific treatment for patients with sepsis, and management relies on infection control and support of organ function. A better understanding of the underlying pathophysiology of this syndrome will help to develop innovative therapies. In this regard, it has been widely reported that endothelial cell activation and dysfunction are major contributors to the development of sepsis. This review aims to provide a comprehensive overview of emerging findings highlighting the prominent role of mitochondria in the endothelial response in in vitro experimental models of sepsis. Additionally, we discuss potential mitochondrial targets that have demonstrated protective effects in preclinical investigations against sepsis. These promising findings hold the potential to pave the way for future clinical trials in the field.

Endoplasmic reticulum stress-mediated cell death in cardiovascular disease

The endoplasmic reticulum (ER) plays a vital function in maintaining cellular homeostasis. Endoplasmic reticulum stress (ERS) can trigger various modes of cell death by activating the unfolded protein response (UPR) signaling pathway. Cell death plays a crucial role in the occurrence and development of diseases such as cancer, liver diseases, neurological diseases, and cardiovascular diseases. Several cardiovascular diseases including hypertension, atherosclerosis, and heart failure are associated with ER stress. ER stress-mediated cell death is of interest in cardiovascular disease. Moreover, an increasing body of evidence supports the potential of modulating ERS for treating cardiovascular disease. This paper provides a comprehensive review of the UPR signaling pathway, the mechanisms that induce cell death, and the modes of cell death in cardiovascular diseases. Additionally, we discuss the mechanisms of ERS and UPR in common cardiovascular diseases, along with potential therapeutic strategies.

High-Density Lipoproteins at the Interface between the NLRP3 Inflammasome and Myocardial Infarction

Despite significant therapeutic advancements, morbidity and mortality following myocardial infarction (MI) remain unacceptably high. This clinical challenge is primarily attributed to two significant factors: delayed reperfusion and the myocardial injury resulting from coronary reperfusion. Following reperfusion, there is a rapid intracellular pH shift, disruption of ionic balance, heightened oxidative stress, increased activity of proteolytic enzymes, initiation of inflammatory responses, and activation of several cell death pathways, encompassing apoptosis, necroptosis, and pyroptosis. The inflammatory cell death or pyroptosis encompasses the activation of the intracellular multiprotein complex known as the NLRP3 inflammasome. High-density lipoproteins (HDL) are endogenous particles whose components can either promote or mitigate the activation of the NLRP3 inflammasome. In this comprehensive review, we explore the role of inflammasome activation in the context of MI and provide a detailed analysis of how HDL can modulate this process.

Cold atmospheric plasma induces the curing mechanism of diabetic wounds by regulating the oxidative stress mediators iNOS and NO, the pyroptotic mediators NLRP-3, Caspase-1 and IL-1β and the angiogenesis mediators VEGF and Ang-1

It has been demonstrated that cold atmospheric plasma (CAP) accelerates the wound healing process, however the underlying molecular pathways behind this effect remain unclear. Thus, the goal of the proposed investigation is to elucidate the therapeutic advantages of CAP on angiogenesis, pyroptotic, oxidative stress, and inflammatory mediators during the wound-healing mechanisms associated with diabetes. Intraperitoneal administration of streptozotocin (STZ, 60 mg/Kg) of body weight was used to induce type-1 diabetes. Seventy-five male mice were randomized into 3 groups: the control non-diabetic group, the diabetic group that was not treated, and the diabetic group that was treated with CAP. The key mediators of pyroptosis and its impact on the slow healing process of diabetic wounds were examined using histological investigations employing H&E staining, immunohistochemistry, ELISA, and Western blotting analysis. Angiogenesis proteins (VEGF, Ang-1, and HO-1) showed a significant decline in expression concentrations in the diabetic wounds, indicating that diabetic animals' wounds were less likely to heal. Furthermore, compared to the controls, the major mediators of pyroptosis (NLRP-3, IL-1β, and caspase-1), oxidative stress (iNOS and NO), and inflammation (TNF-α and IL-6) have higher expression levels in the diabetic wounds. These factors substantially impede the healing mechanism of diabetic wounds. Interestingly, our results disclosed the therapeutic impacts of CAP treatment in the healing process of diabetic wounds via significantly regulating the expression levels of angiogenesis, pyroptosis, oxidative stress and pro-inflammatory mediators. Our findings demonstrated the curative likelihood of CAP and the underlying mechanisms for enhancing the healing process of diabetic wounds.

Hyperoside Prevents Aβ42-Induced Neurotoxicity in PC12 Cells and Caenorhabditis elegans

Traditional Chinese medicines such as hyperoside-rich Acanthopanax senticosus and Crataegus pinnatifida have been confirmed to exhibit anti-oxidative stress properties. Hyperoside, the main ingredient of numerous antioxidant herbs, may have the ability to postpone the onset of neurodegenerative diseases. This study investigates the possible therapeutic mechanism of hyperoside as a natural antioxidant against Alzheimer's disease (AD) in Caenorhabditis elegans and PC12 cells. Specifically, hyperoside reduced reactive oxygen species (ROS) level and Aβ42-induced neurotoxicity in C. elegans worms. Meanwhile, hyperoside reduced ROS production and increased mitochondrial membrane potentialin Aβ42-induced PC12 cells, which possibly due to the increase of antioxidant enzymes activity and the diminution of malondialdehyde levels. Hoechst 33,342 staining and flow cytometry analysis results suggested that hyperoside reverses cell apoptosis. Network pharmacology predicts potentially relevant hyperoside targets and pathways in AD therapy. As anticipated, hyperoside reversed Aβ42-stimulated downregulation of the PI3K/Akt/Nrf2/HO-1. The PI3K inhibitor LY294002 partially abolished the protective capability of hyperoside. The results of molecular docking further indicated that the PI3K/Akt pathways may be involved in the protection of Aβ42-induced PC12 cells by hyperoside treatment. The study provides theoretical information for research and development of hyperoside as an antioxidant dietary supplement.

Bridging the Gap: Investigating the Link between Inflammasomes and Postoperative Cognitive Dysfunction

Postoperative cognitive dysfunction (POCD) is a cluster of cognitive problems that may arise after surgery. POCD symptoms include memory loss, focus inattention, and communication difficulties. Inflammasomes, intracellular multiprotein complexes that control inflammation, may have a significant role in the development of POCD. It has been postulated that the NLRP3 inflammasome promotes cognitive impairment by triggering the inflammatory response in the brain. Nevertheless, there are many gaps in the current literature to understand the underlying pathophysiological mechanisms and develop future therapy. This review article underlines the limits of our current knowledge about the NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome and POCD. We first discuss inflammasomes and their types, structures, and functions, then summarize recent evidence of the NLRP3 inflammasome's involvement in POCD. Next, we propose a hypothesis that suggests the involvement of inflammasomes in multiple organs, including local surgical sites, blood circulation, and other peripheral organs, leading to systemic inflammation and subsequent neuronal dysfunction in the brain, resulting in POCD. Research directions are then discussed, including analyses of inflammasomes in more clinical POCD animal models and clinical trials, studies of inflammasome types that are involved in POCD, and investigations into whether inflammasomes occur at the surgical site, in circulating blood, and in peripheral organs. Finally, we discuss the potential benefits of using new technologies and approaches to study inflammasomes in POCD. A thorough investigation of inflammasomes in POCD might substantially affect clinical practice.

Machine learning-based metabolism-related genes signature, single-cell RNA sequencing, and experimental validation in hypersensitivity pneumonitis

Metabolism is involved in the pathogenesis of hypersensitivity pneumonitis. To identify diagnostic feature biomarkers based on metabolism-related genes (MRGs) and determine the correlation between MRGs and M2 macrophages in patients with hypersensitivity pneumonitis (HP). We retrieved the gene expression matrix from the Gene Expression Omnibus database. The differentially expressed MRGs (DE-MRGs) between healthy control (HC) and patients with HP were identified using the "DESeq2" R package. The "clusterProfiler" R package was used to perform "Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses" on DE-MRGs. We used machine learning algorithms for screening diagnostic feature biomarkers for HP. The "receiver operating characteristic curve" was used to evaluate diagnostic feature biomarkers' discriminating ability. Next, we used the "Cell-type Identification by Estimating Relative Subsets of RNA Transcripts" algorithm to determine the infiltration status of 22 types of immune cells in the HC and HP groups. Single-cell sequencing and qRT-PCR were used to validate the diagnostic feature biomarkers. Furthermore, the status of macrophage polarization in the peripheral blood of patients with HP was determined using flow cytometry. Finally, the correlation between the proportion of M2 macrophages in peripheral blood and the diagnostic biomarker expression profile in HP patients was determined using Spearman analysis. We identified a total of 311 DE-MRGs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that DE-MRGs were primarily enriched in processes like steroid hormone biosynthesis, drug metabolism, retinol metabolism, etc. Finally, we identified NPR3, GPX3, and SULF1 as diagnostic feature biomarkers for HP using machine learning algorithms. The bioinformatic results were validated using the experimental results. The CIERSORT algorithm and flow cytometry showed a significant difference in the proportion of M2 macrophages in the HC and HP groups. The expression of SULF1 was positively correlated with the proportion of M2-type macrophages. In addition, a positive correlation was observed between SULF1 expression and M2 macrophage proportion. Finally, we identified NPR3, GPX3, and SULF1 as diagnostic feature biomarkers for HP. Further, a correlation between SULF1 and M2 macrophages was observed, providing a novel perspective for treating patients with HP and future studies.

GSDME in Endothelial Cells: Inducing Vascular Inflammation and Atherosclerosis via Mitochondrial Damage and STING Pathway Activation

The initiation of atherosclerotic plaque is characterized by endothelial cell inflammation. In light of gasdermin E's (GSDME) role in pyroptosis and inflammation, this study elucidates its function in atherosclerosis onset. Employing Gsdme- and apolipoprotein E-deficient (Gsdme-/-/ApoE-/-) and ApoE-/- mice, an atherosclerosis model was created on a Western diet (WD). In vitro examinations with human umbilical vein endothelial cells (HUVECs) included oxidized low-density lipoprotein (ox-LDL) exposure. To explore the downstream mechanisms linked to GSDME, we utilized an agonist targeting the stimulator of the interferon genes (STING) pathway. The results showed significant GSDME activation in ApoE-/- mice arterial tissues, corresponding with atherogenesis. Gsdme-/-/ApoE-/- mice displayed fewer plaques and decreased vascular inflammation. Meanwhile, GSDME's presence was confirmed in endothelial cells. GSDME inhibition reduced the endothelial inflammation induced by ox-LDL. GSDME was linked to mitochondrial damage in endothelial cells, leading to an increase in cytoplasmic double-stranded DNA (dsDNA). Notably, STING activation partially offset the effects of GSDME inhibition in both in vivo and in vitro settings. Our findings underscore the pivotal role of GSDME in endothelial cells during atherogenesis and vascular inflammation, highlighting its influence on mitochondrial damage and the STING pathway, suggesting a potential therapeutic target for vascular pathologies.

A Photo-Activated Thermoelectric Catalyst for Ferroptosis-/Pyroptosis-Boosted Tumor Nanotherapy

Phototherapy including photothermal therapy (PTT) and photodynamic therapy (PDT) has gradually come into the limelight for oncological treatment due to its noninvasiveness, high specificity, and low side effects. However, upregulated heat-shock proteins (HSPs) and reactive oxygen species (ROS)-defensing system such as glutathione (GSH) or MutT homolog 1 (MTH1) protein in tumor microenvironment counteract the efficiency of single-modality therapy either PTT or PDT. Herein, the well-defined bismuth telluride nanoplates (Bi2 Te3 NPs) are engineered with a high-performance photo-thermo-electro-catalytic effect for tumor-synergistic treatment. Upon near-infrared light illumination, Bi2 Te3 NPs induce a significant temperature elevation for PTT, which effectively inhibits MTH1 expression. Especially, heating and cooling alteration caused temperature variations result in electron-hole separation for ROS generation, which not only damages HSPs to reduce the thermotolerance for enhance PTT, but also arouses tumor cell pyroptosis. Additionally, Bi2 Te3 NPs conspicuously reduce GSH, further improving ROS level and leading to decrease glutathione peroxidase 4 (GPX4) activity, which triggers tumor cell ferroptosis. Due to the photo-thermo-electro-catalytic synergistic therapy, Bi2 Te3 NPs are gifted with impressive tumor suppression on both ectopic and orthotopic ocular tumor models. This work highlights a high-performance multifunctional energy-conversion nanoplatform for reshaping tumor microenvironment to boost the tumor-therapeutic efficacy of phototherapy.

Knockdown of ANLN inhibits the progression of lung adenocarcinoma via pyroptosis activation

Significant advancements have been achieved in the area of molecular targeted therapy for lung adenocarcinoma (LUAD). However, the complex molecular patterns and high heterogeneity of LUAD confine the efficacy of these therapies to a specific subset of patients; therefore, it is necessary to explore novel targets for LUAD treatment. The expression levels of anillin (ANLN) in LUAD were analyzed using the Gene Expression Profiling Interactive Analysis database. Furthermore, the association between ANLN gene expression and patient survival outcomes was evaluated using the Kaplan‑Meier Plotter. Subsequently, small interfering RNA (siRNA) transfection was performed to knock down ANLN in A549 and H1299 cell lines, after which, TUNEL, colony formation and Transwell assays were conducted to assess cell death, colony formation and migration, respectively. Additionally, western blot analysis was performed to analyze the expression levels of caspase‑1, interleukin (IL)‑18 (IL‑18), IL‑1β, NLR family pyrin domain‑containing 3 (NLRP3), apoptosis‑associated speck‑like protein containing a CARD domain (ASC) and cleaved gasdermin D (GSDMD) following ANLN knockdown. The results revealed that ANLN mRNA expression was significantly increased in LUAD tissues compared with adjacent normal samples. Furthermore, the expression levels of ANLN displayed an increasing trend with advancing clinical stage. Furthermore, patients with high ANLN expression levels exhibited poor overall survival rates compared with those with low ANLN expression levels. Subsequent ANLN knockdown experiments indicated elevated cell death rate, and reduced colony formation and migration in both A549 and H1299 cells. Additionally, ANLN knockdown resulted in increased protein expression levels of pyroptosis‑associated molecules, including caspase‑1, NLRP3, cleaved‑GSDMD, IL‑1β, ASC and IL‑18 in both A549 and H1299 cells. In conclusion, ANLN represents an important gene and a promising therapeutic target for LUAD. Its potential as a therapeutic target makes it an interesting candidate for further exploration in the development of novel treatment strategies for LUAD.

Effect of caspase-1 (CASP1) combined with multimodal ultrasound features on the prognosis of breast cancer patients

Background

Breast cancer (BRCA) is the malignant tumor with the highest incidence rate among women in the world, and its mortality rate ranks second. The purpose of our study is to explore the correlation between caspase-1 (CASP1) and the prognosis of BRCA patients and the potential mechanism of action, and to analyze the clinical value of CASP1 combined with multimodal ultrasound features in early screening and prognosis of BRCA.

Methods

We analyzed The Cancer Genome Atlas (TCGA) database to confirm that CASP1 was expressed in BRCA patients and determine whether its expression was correlated with patient prognosis. The relationship between CASP1 expression and survival was measured by the clinicopathological parameters. Multivariate analysis was performed using Cox regression, and a nomogram was developed using these results for quality assurance purposes. The correlations between CASP1 and immune cells were investigated using the Tumor Immune Estimation Resource (TIMER) and TCGA databases. Next, we performed gene set enrichment analysis (GSEA) to determine the potential mechanism of action. Finally, to analyze the effect of CASP1 combined with multimodal ultrasonography characteristics on the prognosis of BRCA patients was studied by analyzing the clinical data of patients.

Results

CASP1 expression was lower in BRCA tumor tissues than in the surrounding tissues. Patients with high CASP1 expression had better overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI) than those with low CASP1 expression. GSEA suggested that CASP1 may affect the cell cycle, immune environment, inflammation, apoptosis, the HIPPOMERLIN pathway, Natural killer (NK) cell regulation of cytotoxicity, p53 expression, the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, the mitogen-activated protein kinase (MAPK) pathway, extracellular matrix, etc., thereby influencing the biological events in BRCA. Among conventional ultrasound features and contrast-enhanced ultrasound (CEUS) features, mass margin status and blood flow grade were associated with the expression of CASP1. Meanwhile, patients with poor ultrasound features tended to have low CASP1 expression.

Conclusions

CASP1 may be a novel predictive marker for BRCA patients. CASP1 combined with multimodal ultrasound features has good clinical value in the early screening and prognostic prediction of BRCA.

The signature of cuproptosis-related immune genes predicts the tumor microenvironment and prognosis of prostate adenocarcinoma

Background

Cuproptosis plays a crucial role in cancer, and different subtypes of cuproptosis have different immune profiles in prostate adenocarcinoma (PRAD). This study aimed to investigate immune genes associated with cuproptosis and develop a risk model to predict prognostic characteristics and chemotherapy/immunotherapy responses of patients with PRAD.

Methods

The CIBERSORT algorithm was used to evaluate the immune and stromal scores of patients with PRAD in The Cancer Genome Atlas (TCGA) cohort. Validation of differentially expressed genes DLAT and DLD in benign and malignant tissues by immunohistochemistry, and the immune-related genes of DLAT and DLD were further screened. Univariable Cox regression were performed to select key genes. Least absolute shrinkage and selection operator (LASSO)-Cox regression analyse was used to develop a risk model based on the selected genes. The model was validated in the TCGA, Memorial Sloan-Kettering Cancer Center (MSKCC) and Gene Expression Omnibus (GEO) datasets, as well as in this study unit cohort. The genes were examined via functional enrichment analysis, and the tumor immune features, tumor mutation features and copy number variations (CNVs) of patients with different risk scores were analysed. The response of patients to multiple chemotherapeutic/targeted drugs was assessed using the pRRophetic algorithm, and immunotherapy was inferred by the Tumor Immune Dysfunction and Exclusion (TIDE) and immunophenoscore (IPS).

Results

Cuproptosis-related immune risk scores (CRIRSs) were developed based on PRLR, DES and LECT2. High CRIRSs indicated poor overall survival (OS), disease-free survival (DFS) in the TCGA-PRAD, MSKCC and GEO datasets and higher T stage and Gleason scores in TCGA-PRAD. Similarly, in the sample collected by the study unit, patients with high CRIRS had higher T-stage and Gleason scores. Additionally, higher CRIRSs were negatively correlated with the abundance of activated B cells, activated CD8+ T cells and other stromal or immune cells. The expression of some immune checkpoints was negatively correlated with CRIRSs. Tumor mutational burden (TMB), mutant-allele tumor heterogeneity (MATH) and copy number variation (CNV) scores were all higher in the high-CRIRS group. Multiple chemotherapeutic/targeted drugs and immunotherapy had better responsiveness in the low-CRIRS group.

Conclusion

Overall, lower CRIRS indicated better response to treatment strategies and better prognostic outcomes.

MiR-195-5p is involved in testicular ischemia/reperfusion injury by directly targeting PELP1 and regulating spermatogonia pyroptosis

BACKGROUND AND OBJECTIVE

Ischemia/reperfusion injury (IRI), which is characterized by testicular torsion and causes permanent impairment of spermatogenic function, is linked with pyroptosis. Studies have implicated endogenous small non-coding RNAs in IRI development across various organs. In this study, we elucidated the mechanism underlying miR-195-5p's action in regulating pyroptosis in testicular IRI.

METHODS

We established two models, namely a testicular torsion/ detorsion (T/D) mouse model and an oxygen-glucose deprivation/reperfusion (OGD/R)-treated germ cell model. Hematoxylin and eosin staining was performed to evaluate the testicular ischemic injury. The expression of pyroptosis-related proteins and reactive oxygen species production in testis tissues were detected using Western blotting, quantitative real-time PCR, malondialdehyde and superoxide dismutase assay kits and immunohistochemistry. Cell viability and cytotoxicity were evaluated using CCK-8 and LDH assays, whereas expression patterns of inflammatory proteins were measured using ELISA, immunofluorescence, and western blot assays. miR-195-5p interaction with PELP1 was validated by conducting the luciferase enzyme reporter test.

RESULTS

Pyroptosis-related proteins NLRP3, GSDMD, IL-1β, and IL-18 were significantly upregulated following testicular IRI. A similar pattern was observed in the OGD/R model. miR-195-5p was significantly downregulated in mouse IRI testis tissue and OGD/R-treated GC-1 cells. Notably, miR-195-5p downregulation promoted whereas its upregulation attenuated pyroptosis in OGD/R-treated GC-1 cells. Furthermore, we found that PELP1 is a miR-195-5p target. miR-195-5p attenuated pyroptosis in GC-1 cells by inhibiting PELP1 expression during OGD/R, and this protective effect was blocked upon miR-195-5p downregulation. Collectively, these results indicated that miR-195-5p inhibits testicular IRI-induced pyroptosis by targeting PELP1, suggesting that it has the potential to serve as a novel target for the future development of therapies for testicular torsion.

A Mendelian randomisation, propensity score matching study to investigate causal association between serum homocysteine and intracranial aneurysm

BACKGROUND AND PURPOSE

Recent observational studies have reported that serum total homocysteine (tHcy) is associated with intracranial aneurysms (IAs). However, the causal effect of tHcy on IAs is unknown. We leveraged large-scale genetic association and real-world data to investigate the causal effect of tHcy on IA formation.

METHODS

We performed a two-sample Mendelian randomisation (MR) using publicly available genome-wide association studies summary statistics to investigate the causal relationship between tHcy and IAs, following the recommendations of the Strengthening the Reporting of Observational Studies in Epidemiology-MR statement. Furthermore, a propensity score matching (PSM) analysis was conducted to evaluate the detailed effects of tHcy on risk of IA formation by utilizing real-world multicentre data, including 9902 patients with and without IAs (1:1 matched). Further interaction and subgroup analyses were performed to elucidate how tHcy affects risk of IA formation.

RESULTS

MR analyses indicated that genetically determined tHcy was causally associated with IA risk (OR, 1.38, 95% CI 1.07 to 1.79; p=0.018). This is consistent with the more conservative weighted median analysis (OR, 1.41, 95% CI 1.03 to 1.93; p=0.039). Further sensitivity analyses showed no evidence of horizontal pleiotropy or heterogeneity of single nucleotide polymorphisms in causal inference. According to the PSM study, we found that, compared with low tHcy (≤15 µmol/L), moderate tHcy (>15-30 µmol/L) (OR 2.13, 95% CI 1.93 to 2.36) and high tHcy (>30 µmol/L) (OR 3.66, 95% CI 2.71 to 4.95) were associated with a higher IA risk (p trend <0.001). Subgroup analyses demonstrated significant ORs of tHcy in each subgroup when stratified by traditional cardiovascular risk factors. Furthermore, there was also a synergistic effect of tHcy and hypertension on IA risk (p interaction <0.001; the relative excess risk due to interaction=1.65, 95% CI 1.29 to 2.01).

CONCLUSION

Both large-scale genetic evidence and multicentre real-world data support a causal association between tHcy and risk of IA formation. Serum tHcy may serve as a biomarker to identify high-risk individuals who would particularly benefit from folate supplementation.

Association between homocysteine level and length of stay in patients with lower extremity atherosclerotic disease: a retrospective cohort study

OBJECTIVES

Homocysteine (Hcy) level has been widely identified as a risk factor associated with adverse outcomes in patients with lower extremity atherosclerotic disease (LEAD). However, there are still some knowledge gaps in research on the association between Hcy level and downstream adverse outcomes, such as length of stay (LOS). This study aims to explore whether and to what extent Hcy level is associated with LOS in patients with LEAD.

DESIGN

Retrospective cohort study.

SETTING

China.

PARTICIPANTS, PRIMARY AND SECONDARY OUTCOMES

We conducted a retrospective cohort study of 748 patients from inpatients with LEAD between January 2014 and November 2021 at the First Hospital of China Medical University in China. We used a slew of generalised linear models to evaluate the association between Hcy level and LOS.

RESULTS

The patients' median age was 68 years and 631 (84.36%) were males. A dose-response curve with an inflection point at 22.63 µmol/L was observed between Hcy level and LOS after the adjustment of potential confounders. LOS increased before Hcy level reached the inflection point (β: 0.36; 95% CI: 0.18 to 0.55; p<0.001).ConclusionOur results show that an Hcy level <22.63 µmol/L is associated with increased LOS in patients with LEAD, which was independent of some other risk factors. This might shed light on how Hcy can be used as a key marker in the comprehensive management of patients with LEAD during hospitalisation.

Mechanisms of systemic low-grade inflammation in HIV patients on long-term suppressive antiretroviral therapy: the inflammasome hypothesis

OBJECTIVE

We aimed to determine the contribution of inflammasome activation in chronic low-grade systemic inflammation observed in patients with HIV (PWH) on long-term suppressive antiretroviral therapy (ART) and to explore mechanisms of such activation.

DESIGN

Forty-two PWH on long-term suppressive ART (HIV-RNA < 40 copies/ml) were compared with 10 HIV-negative healthy controls (HC).

METHODS

Inflammasome activation was measured by dosing mature interleukin (IL)-1β and IL-18 cytokines in patient serum. We explored inflammasome pathways through ex vivo stimulation of PWH primary monocytes with inflammasome activators; expression of inflammasome components by transcriptomic analysis; and metabolomics analysis of patient sera.

RESULTS

Median (Q1; Q3) age, ART and viral suppression duration in PWH were 54 (48; 60), 15 (9; 20) and 7.5 (5; 12) years, respectively. Higher serum IL-18 was measured in PWH than in HC (61 (42; 77) vs. 36 (27-48 pg/ml), P = 0.009); IL-1β was detected in 10/42 PWH (0.5 (0.34; 0.80) pg/ml) but not in HC. Monocytes from PWH did not produce more inflammatory cytokines in vitro , but secretion of IL-1β in response to NOD like receptor family, pyrin domain containing 3 (NLRP3) inflammasome stimulation was higher than in HC. This was not explained at the transcriptional level. We found an oxidative stress molecular profile in PWH sera.

CONCLUSION

HIV infection with long-term effective ART is associated with a serum inflammatory signature, including markers of inflammasome activation, and an increased activation of monocytes upon inflammasome stimulation. Other cells should be investigated as sources of inflammatory cytokines in PWH. Oxidative stress might contribute to this chronic low-grade inflammation.

Role of pyroptosis in the pathogenesis and treatment of diseases

Programmed cell death (PCD) is regarded as a pathological form of cell death with an intracellular program mediated, which plays a pivotal role in maintaining homeostasis and embryonic development. Pyroptosis is a new paradigm of PCD, which has received increasing attention due to its close association with immunity and disease. Pyroptosis is a form of inflammatory cell death mediated by gasdermin that promotes the release of proinflammatory cytokines and contents induced by inflammasome activation. Recently, increasing evidence in studies shows that pyroptosis has a crucial role in inflammatory conditions like cardiovascular diseases (CVDs), cancer, neurological diseases (NDs), and metabolic diseases (MDs), suggesting that targeting cell death is a potential intervention for the treatment of these inflammatory diseases. Based on this, the review aims to identify the molecular mechanisms and signaling pathways related to pyroptosis activation and summarizes the current insights into the complicated relationship between pyroptosis and multiple human inflammatory diseases (CVDs, cancer, NDs, and MDs). We also discuss a promising novel strategy and method for treating these inflammatory diseases by targeting pyroptosis and focus on the pyroptosis pathway application in clinics.

The role of pyroptosis in inflammatory diseases

Programmed cell death has crucial roles in the physiological maturation of an organism, the maintenance of metabolism, and disease progression. Pyroptosis, a form of programmed cell death which has recently received much attention, is closely related to inflammation and occurs via canonical, non-canonical, caspase-3-dependent, and unclassified pathways. The pore-forming gasdermin proteins mediate pyroptosis by promoting cell lysis, contributing to the outflow of large amounts of inflammatory cytokines and cellular contents. Although the inflammatory response is critical for the body's defense against pathogens, uncontrolled inflammation can cause tissue damage and is a vital factor in the occurrence and progression of various diseases. In this review, we briefly summarize the major signaling pathways of pyroptosis and discuss current research on the pathological function of pyroptosis in autoinflammatory diseases and sterile inflammatory diseases.

Trimethylamine N-Oxide (TMAO) Inducing Endothelial Injury: UPLC-MS/MS-Based Quantification and the Activation of Cathepsin B-Mediated NLRP3 Inflammasome

TMAO is a new risk biomarker for cardiovascular disease. With trimethylammonium as its main chemical skeleton, TMAO is structurally similar to many endogenous metabolites, such as acetylcholine, carnitine, phosphorylcholine, etc. The mechanism of TMAO on the pathological process of CVD is still unclear. In this study, the quantitative analysis of plasma TMAO is conducted, and the contribution of Cathepsin B and NLRP3 inflammasome during the process of TMAO-induced endothelial injury was proposed and investigated at animal and cellular levels. Immunofluorescence assay was applied to represent the protein expression of Cathepsin B and NLRP3 inflammasome located at endothelial cells. The results showed that TMAO could disrupt endothelial cells permeability to induce endothelial injury, meanwhile, TMAO could increase NLRP3 inflammasome activation and promote the activity and expression of Cathepsin B in vitro and in vivo, whereas inhibition of NLRP3 inflammasome activation by MCC950 could protect the endothelial cells from TMAO associated endothelial injury via Cathepsin B. The study reveals that TMAO can cause endothelial injury via Cathepsin B-dependent NLRP3 inflammasome, and inhibition of Cathepsin B and NLRP3 inflammasome can reduce the TMAO-induced damage. The results provide new insight into the role of TMAO in CVD, which can be a potential therapeutic target for disease treatment and drug design.

Pyroptosis in platelets: Thrombocytopenia and inflammation

OBJECTIVE

The purpose of this manuscript was to conclude the role of platelets in immune inflammation and discuss the complex mechanisms of pyroptosis in platelets as well as their related diseases.

METHODS

This article reviewed the existing literature to see the development of pyroptosis in platelets.

RESULTS

Platelets have been shown to be capable of activating inflammasomes assembled from NOD-like receptor family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1. Recently, they were also implicated in pyroptosis. Cleaved by caspase-1, N-terminal gasdermin D (N-GSDMD) could form pores in the cell membrane, inducing nonselective intracellular substance release. This programmed cell death induced thrombocytopenia and inflammatory cytokine release such as IL-1β and IL-18, promoting platelet aggregation, vaso-occlusion, endothelial permeability and cascaded inflammatory response.

CONCLUSION

Pyroptosis in platelets contributes to thrombocytopenia and inflammation.

An updated review on cell signaling pathways regulated by candidate miRNAs in coronary artery disease

MicroRNAs (miRNAs) are small endogenous non-coding RNA, size range from 17 to 25 nucleotides that regulate gene expression at the post-transcriptional level. More than 2000 different types of miRNAs have been identified in humans which regulate about 60% of gene expression, since the discovery of the first miRNA in 1993. MicroRNA performs many functions such as being involved in the regulation of various biological pathways for example cell migration, cell proliferation, cell differentiation, disease progression, and initiation. miRNAs also play an important role in the development of atherosclerosis lesions, cardiac fibroblast, cardiac hypertrophy, cancer, and neurological disorders. Abnormal activation of many cell signaling pathways has been observed in the development of coronary artery disease. Abnormal expression of these candidate miRNA genes leads to up or downregulation of specific genes, these specific genes play an important role in the regulation of cell signaling pathways involved in coronary artery disease. Many studies have found that miRNAs play a key role in the regulation of crucial signaling pathways that are involved in the pathophysiology of coronary artery disease. This review is designed to investigate the role of cell signaling pathways regulated by candidate miRNAs in Coronary artery disease.

Mitochondrial-Targeted Delivery of Polyphenol-Mediated Antioxidases Complexes against Pyroptosis and Inflammatory Diseases

Excess accumulation of mitochondrial reactive oxygen species (mtROS) is a key target for inhibiting pyroptosis-induced inflammation and tissue damage. However, targeted delivery of drugs to mitochondria and efficient clearance of mtROS remain challenging. In current study, it is discovered that polyphenols such as tannic acid (TA) can mediate the targeting of polyphenol/antioxidases complexes to mitochondria. This affinity does not depend on mitochondrial membrane potential but stems from the strong binding of TA to mitochondrial outer membrane proteins. Taking advantage of the feasibility of self-assembly between TA and proteins, superoxide dismutase, catalase, and TA are assembled into complexes (referred to as TSC) for efficient enzymatic activity maintenance. In vitro fluorescence confocal imaging shows that TSC not only promoted the uptake of biological enzymes in hepatocytes but also highly overlapped with mitochondria after lysosomal escape. The results from an in vitro model of hepatocyte oxidative stress demonstrate that TSC efficiently scavenges excess mtROS and reverses mitochondrial depolarization, thereby inhibiting inflammasome-mediated pyroptosis. More interestingly, TSC maintain superior efficacy compared with the clinical gold standard drug N-acetylcysteine in both acetaminophen- and D-galactosamine/lipopolysaccharide-induced pyroptosis-related hepatitis mouse models. In conclusion, this study opens a new paradigm for targeting mitochondrial oxidative stress to inhibit pyroptosis and treat inflammatory diseases.

Caspase-11 promotes high-fat diet-induced NAFLD by increasing glycolysis, OXPHOS, and pyroptosis in macrophages

Introduction

Non-alcoholic fatty liver disease (NAFLD) has a global prevalence of 25% of the population and is a leading cause of cirrhosis and hepatocellular carcinoma. NAFLD ranges from simple steatosis (non-alcoholic fatty liver) to non-alcoholic steatohepatitis (NASH). Hepatic macrophages, specifically Kupffer cells (KCs) and monocyte-derived macrophages, act as key players in the progression of NAFLD. Caspases are a family of endoproteases that provide critical connections to cell regulatory networks that sense disease risk factors, control inflammation, and mediate inflammatory cell death (pyroptosis). Caspase-11 can cleave gasdermin D (GSDMD) to induce pyroptosis and specifically defends against bacterial pathogens that invade the cytosol. However, it's still unknown whether high fat diet (HFD)-facilitated gut microbiota-generated cytoplasmic lipopolysaccharides (LPS) activate caspase-11 and promote NAFLD.

Methods

To examine this hypothesis, we performed liver pathological analysis, RNA-seq, FACS, Western blots, Seahorse mitochondrial stress analyses of macrophages and bone marrow transplantation on HFD-induced NAFLD in WT and Casp11-/- mice.

Results and Discussion

Our results showed that 1) HFD increases body wight, liver wight, plasma cholesterol levels, liver fat deposition, and NAFLD activity score (NAS score) in wild-type (WT) mice; 2) HFD increases the expression of caspase-11, GSDMD, interleukin-1β, and guanylate-binding proteins in WT mice; 3) Caspase-11 deficiency decreases fat liver deposition and NAS score; 4) Caspase-11 deficiency decreases bone marrow monocyte-derived macrophage (MDM) pyroptosis (inflammatory cell death) and inflammatory monocyte (IM) surface GSDMD expression; 5) Caspase-11 deficiency re-programs liver transcriptomes and reduces HFD-induced NAFLD; 6) Caspase-11 deficiency decreases extracellular acidification rates (glycolysis) and oxidative phosphorylation (OXPHOS) in inflammatory fatty acid palmitic acid-stimulated macrophages, indicating that caspase-11 significantly contributes to maintain dual fuel bioenergetics-glycolysis and OXPHOS for promoting pyroptosis in macrophages. These results provide novel insights on the roles of the caspase-11-GSDMD pathway in promoting hepatic macrophage inflammation and pyroptosis and novel targets for future therapeutic interventions involving the transition of NAFLD to NASH, hyperlipidemia, type II diabetes, metabolic syndrome, metabolically healthy obesity, atherosclerotic cardiovascular diseases, autoimmune diseases, liver transplantation, and hepatic cancers.

Mechanism of homocysteine-mediated endothelial injury and its consequences for atherosclerosis

Homocysteine (Hcy) is an intermediate amino acid formed during the conversion from methionine to cysteine. When the fasting plasma Hcy level is higher than 15 μmol/L, it is considered as hyperhomocysteinemia (HHcy). The vascular endothelium is an important barrier to vascular homeostasis, and its impairment is the initiation of atherosclerosis (AS). HHcy is an important risk factor for AS, which can promote the development of AS and the occurrence of cardiovascular events, and Hcy damage to the endothelium is considered to play a very important role. However, the mechanism by which Hcy damages the endothelium is still not fully understood. This review summarizes the mechanism of Hcy-induced endothelial injury and the treatment methods to alleviate the Hcy induced endothelial dysfunction, in order to provide new thoughts for the diagnosis and treatment of Hcy-induced endothelial injury and subsequent AS-related diseases.

The role of pyroptosis in endothelial dysfunction induced by diseases

Most organs in the body rely on blood flow, and vesicular damage is the leading cause of injury in multiple organs. The endothelium, as the barriers of vessels, play a critical role in ensuring vascular homeostasis and angiogenesis. The rapid development of risk factors in endothelial injuries has been seen in the past decade, such as smoking, infectious, and diabetes mellites. Pyroptotic endothelium is an inflammatory mode of governed endothelial cell death that depend on the metabolic disorder and severe infectious such as atherosclerosis, and sepsis-related acute lung injury, respectively. Pyroptotic endothelial cells need GSDMD cleaved into N- and C-terminal by caspase1, and the cytokines are released by a pore constructed by the N-terminal of GSDMD in the membrane of ECs, finally resulting in severe inflammation and pyroptotic cell death. This review will focus on the patho-physiological and pharmacological pathways of pyroptotic endothelial metabolism in diseases. Overall, this review indicates that pyroptosis is a significant risk factor in diseases and a potential drug target in related diseases.

The role of pyroptosis in endothelial dysfunction induced by diseases

Most organs in the body rely on blood flow, and vesicular damage is the leading cause of injury in multiple organs. The endothelium, as the barriers of vessels, play a critical role in ensuring vascular homeostasis and angiogenesis. The rapid development of risk factors in endothelial injuries has been seen in the past decade, such as smoking, infectious, and diabetes mellites. Pyroptotic endothelium is an inflammatory mode of governed endothelial cell death that depend on the metabolic disorder and severe infectious such as atherosclerosis, and sepsis-related acute lung injury, respectively. Pyroptotic endothelial cells need GSDMD cleaved into N- and C-terminal by caspase1, and the cytokines are released by a pore constructed by the N-terminal of GSDMD in the membrane of ECs, finally resulting in severe inflammation and pyroptotic cell death. This review will focus on the patho-physiological and pharmacological pathways of pyroptotic endothelial metabolism in diseases. Overall, this review indicates that pyroptosis is a significant risk factor in diseases and a potential drug target in related diseases.

Association of methylenetetrahydrofolate reductase (MTHFR) rs1801133 (677C>T) gene polymorphism with ischemic stroke risk in different populations: An updated meta-analysis

Background: Recently, increasing evidence has implicated methylenetetrahydrofolate reductase (MTHFR) gene mutation as a risk factor for ischemic stroke (IS) in the general population. However, studies have been inconclusive and lack evidence on specific populations. We aim to determine whether the rs1801133 (NC_000001.11 (MTHFR):g. 677C>T (p.Ala222Val) variant, we termed as MTHFR rs1801133 (677 C>T), is linked to an increased risk of IS in different age groups and ancestry groups. Methods: The literature relevant to our study was found by searching the PubMed, Cochrane Library, Web of Science, EMBASE, and CNKI databases. A random effect model analysis was used to calculate the pooled odds ratio (OR) and 95% confidence interval (CI) to evaluate any possible association. We conducted a subgroup analysis based on the age and ancestry groups of the included populations. Results: As of March 2022, 1,925 citations had been identified in electronic databases, of which 96 studies involving 34,814 subjects met our eligibility criteria. A strong link was found between IS and the MTHFR gene rs1801133 (677C>T) polymorphism in all genetic models [dominant genetic model (OR = 1.47; 95%CI = 1.33-1.61; p < 0.001), recessive genetic model (OR = 1.52; 95%CI = 1.36-1.71; p < 0.001), heterozygous model (OR = 1.36; 95%CI = 1.24-1.48; p < 0.001), homozygous model (OR = 1.82; 95%CI = 1.58-2.11; p < 0.001), and T allelic genetic model (OR = 1.37; 95%CI = 1.27-1.48; p < 0.001)]. Further subgroup analyses indicated that the MTHFR rs1801133 (677C>T) variant may increase the risk of IS in Asian, Hispanic, or Latin population, middle-aged, and elderly populations (p < 0.001). Conclusion: Our results implied that mutation of the T allele of MTHFR rs1801133 (677C>T) could be a risk factor for IS. A significant association was found among Asian, Hispanic, or Latin population, middle-aged, and elderly people.

Alantolactone induces concurrent apoptosis and GSDME-dependent pyroptosis of anaplastic thyroid cancer through ROS mitochondria-dependent caspase pathway

BACKGROUND

Anaplastic thyroid cancer (ATC) is one of the fatal cancers and has not effective treatments. Alantolactone (ATL), a terpenoid extracted from traditional Chinese medicinal herb Inula helenium L., confers significant anti-inflammatory, antibacterial and antitumor activity. However, the activity and mechanisms of ATL in ATC remain unclear.

PURPOSE

To investigate the potential anti-ATC effects in vitro and in vivo and the mechanisms involved.

METHODS

The anti-proliferative activity of Alantolactone (ATL) against ATC cells was analyzed through CCK-8 and colony formation assays. Flow cytometry assay was performed to assess the cell cycle, cell apoptosis, ROS, and mitochondrial membrane potential (ΔΨm), whereas the cellular localization of cytochrome c and calreticulin were determined using cellular immunofluorescence assays. The lactate dehydrogenase (LDH) enzyme activity in the cell culture medium was measured using a commercial LDH kit, whereas ELISA was conducted to assess the secretory function of IL-1β. Western blot assays were conducted to determine the expression or regulation of proteins associated with apoptosis and pyroptosis. Subcutaneous tumor model of nude mice was established to evaluate the anticancer activity of ATL in vivo. The expression of Ki67, cyclin B1, cleaved-PARP, cleaved-caspase 3, and IL-1β in the animal tumor tissues was profiled using immunohistochemistry analyses.

RESULTS

Our data showed that ATL significantly inhibited the proliferation and colony formation activity of ATC cells. ATL induced ATC cell cycle arrest at G2/M phase, and downregulated the expression of cyclin B1 and CDC2. Furthermore, ATL induced concurrent apoptosis and pyroptosis in the ATC cells, and the cleavage of PARP and GSDME. It also significantly increased the release of LDH and IL-1β. Mechanically, ATL-mediated increase in ROS suppressed the Bcl-2/Bax ratio, downregulated the mitochondrial membrane potential and increased the release of cytochrome c, leading to caspase 9 and caspase 3 cleavage. We also found that ATL induced the translocation of an immunogenic cell death marker (calreticulin) to the cell membrane. In addition, it inhibited the growth of the ATC subcutaneous xenograft model, and activated proteins associated with apoptosis and pyroptosis, with a high safety profile.

CONCLUSION

Taken together, these results firstly demonstrated that ATL exerted an anti-ATC activity by inducing concurrent apoptosis and GSDME-dependent pyroptosis through ROS-mediated mitochondria-dependent caspase activation. Meanwhile, these cell deaths exhibited obvious characteristics of immunogenic cell death, which may synergistically increase the potential of cancer immunotherapy in ATC. Further studies are needed to explore deeper mechanisms for the anti- ATC activity of ATL.

Capecitabine induces hand-foot syndrome through elevated thymidine phosphorylase-mediated locoregional toxicity and GSDME-driven pyroptosis that can be relieved by tipiracil

BACKGROUND

Hand-foot syndrome (HFS) is a serious dose-limiting cutaneous toxicity of capecitabine-containing chemotherapy, leading to a deteriorated quality of life and negative impacts on chemotherapy treatment. The symptoms of HFS have been widely reported, but the precise molecular and cellular mechanisms remain unknown. The metabolic enzyme of capecitabine, thymidine phosphorylase (TP) may be related to HFS. Here, we investigated whether TP contributes to the HFS and the molecular basis of cellular toxicity of capecitabine.

METHODS

TP-/- mice were generated to assess the relevance of TP and HFS. Cellular toxicity and signalling mechanisms were assessed by in vitro and in vivo experiments.

RESULTS

TP-/- significantly reduced capecitabine-induced HFS, indicating that the activity of TP plays a critical role in the development of HFS. Further investigations into the cellular mechanisms revealed that the cytotoxicity of the active metabolite of capecitabine, 5-DFUR, was attributed to the cleavage of GSDME-mediated pyroptosis. Finally, we demonstrated that capecitabine-induced HFS could be reversed by local application of the TP inhibitor tipiracil.

CONCLUSION

Our findings reveal that the presence of elevated TP expression in the palm and sole aggravates local cell cytotoxicity, further explaining the molecular basis underlying 5-DFUR-induced cellular toxicity and providing a promising approach to the therapeutic management of HFS.

Effects of four weeks lasting aerobic physical activity on cardiovascular biomarkers, oxidative stress and histomorphometric changes of heart and aorta in rats with experimentally induced hyperhomocysteinemia

The aim of this study was to examine the effects of hyperhomocysteinemia and aerobic physical activity on changes of cardiovascular biomarkers in sera, oxidative stress in cardiac tissue, and histomorphometric parameters of heart and aorta in rats. Experiments were conducted on male Wistar albino rats organized into four groups (n = 10, per group): C (control group): 0.9% NaCl 0.2 mL/day; H (homocysteine group): homocysteine 0.45 µmol/g b.w./day; CPA (control + physical activity group): 0.9% NaCl 0.2 mL/day and a program of physical activity on a treadmill; and HPA (homocysteine + physical activity group) homocysteine 0.45 µmol/g b.w./day and a program of physical activity on a treadmill. Substances were applied subcutaneously twice a day. Lipid peroxidation and relative activity of Mn-superoxide dismutase isoform were significantly higher in active hyperhomocysteinemic rats in comparison to sedentary animals. Atherosclerotic plaques were detected in aorta samples of active hyperhomocysteinemic rats and also, they had increased left ventricle wall and interventricular septum, and transverse diameter of cardiomyocytes compared to sedentary groups. Aerobic physical activity in the condition of hyperhomocysteinemia can lead to increased oxidative stress in cardiac tissue and changes in histomorphometric parameters of the heart and aorta, as well increased lipid parameters and cardiac damage biomarkers in sera of rats.

Inflammation and oxidative stress in salt sensitive hypertension; The role of the NLRP3 inflammasome

Salt-sensitivity of blood pressure is an independent risk factor for cardiovascular disease and affects approximately half of the hypertensive population. While the precise mechanisms of salt-sensitivity remain unclear, recent findings on body sodium homeostasis and salt-induced immune cell activation provide new insights into the relationship between high salt intake, inflammation, and hypertension. The immune system, specifically antigen-presenting cells (APCs) and T cells, are directly implicated in salt-induced renal and vascular injury and hypertension. Emerging evidence suggests that oxidative stress and activation of the NLRP3 inflammasome drive high sodium-mediated activation of APCs and T cells and contribute to the development of renal and vascular inflammation and hypertension. In this review, we summarize the recent insights into our understanding of the mechanisms of salt-sensitive hypertension and discuss the role of inflammasome activation as a potential therapeutic target.

The emerging role of pyroptosis-related inflammasome pathway in atherosclerosis

Atherosclerosis (AS), a chronic sterile inflammatory disorder, is one of the leading causes of mortality worldwide. The dysfunction and unnatural death of plaque cells, including vascular endothelial cells (VEC), macrophages, and vascular smooth muscle cells (VSMC), are crucial factors in the progression of AS. Pyroptosis was described as a form of cell death at least two decades ago. It is featured by plasma membrane swelling and rupture, cell lysis, and consequent robust release of cytosolic contents and pro-inflammatory mediators, including interleukin-1β (IL-1β), IL-18, and high mobility group box 1 (HMGB1). Pyroptosis of plaque cells is commonly observed in the initiation and development of AS, and the levels of pyroptosis-related proteins are positively correlated with plaque instability, indicating the crucial contribution of pyroptosis to atherogenesis. Furthermore, studies have also identified some candidate anti-atherogenic agents targeting plaque cell pyroptosis. Herein, we summarize the research progress in understating (1) the discovery and definition of pyroptosis; (2) the characterization and molecular mechanisms of pyroptosis; (3) the regulatory mechanisms of pyroptosis in VEC, macrophage, and VSMC, as well as their potential role in AS progression, aimed at providing therapeutic targets for the prevention and treatment of AS.

miR-193b-3p Promotes Proliferation of Goat Skeletal Muscle Satellite Cells through Activating IGF2BP1

As a well-known cancer-related miRNA, miR-193b-3p is enriched in skeletal muscle and dysregulated in muscle disease. However, the mechanism underpinning this has not been addressed so far. Here, we probed the impact of miR-193b-3p on myogenesis by mainly using goat tissues and skeletal muscle satellite cells (MuSCs), compared with mouse C2C12 myoblasts. miR-193b-3p is highly expressed in goat skeletal muscles, and ectopic miR-193b-3p promotes MuSCs proliferation and differentiation. Moreover, insulin-like growth factor-2 mRNA-binding protein 1 (IGF2BP1) is the most activated insulin signaling gene when there is overexpression of miR-193b-3p; the miRNA recognition element (MRE) within the IGF1BP1 3' untranslated region (UTR) is indispensable for its activation. Consistently, expression patterns and functions of IGF2BP1 were similar to those of miR-193b-3p in tissues and MuSCs. In comparison, ectopic miR-193b-3p failed to induce PAX7 expression and myoblast proliferation when there was IGF2BP1 knockdown. Furthermore, miR-193b-3p destabilized IGF2BP1 mRNA, but unexpectedly promoted levels of IGF2BP1 heteronuclear RNA (hnRNA), dramatically. Moreover, miR-193b-3p could induce its neighboring genes. However, miR-193b-3p inversely regulated IGF2BP1 and myoblast proliferation in the mouse C2C12 myoblast. These data unveil that goat miR-193b-3p promotes myoblast proliferation via activating IGF2BP1 by binding to its 3' UTR. Our novel findings highlight the positive regulation between miRNA and its target genes in muscle development, which further extends the repertoire of miRNA functions.

Exercise-Linked Skeletal Irisin Ameliorates Diabetes-Associated Osteoporosis by Inhibiting the Oxidative Damage-Dependent miR-150-FNDC5/Pyroptosis Axis

Recent evidence suggests that physical exercise (EX) promotes skeletal development. However, the impact of EX on the progression of bone loss and deterioration of mechanical strength in mice with type 2 diabetic mellitus (T2DM) remains unexplored. In the current study, we investigated the effect of EX on bone mass and mechanical quality using a diabetic mouse model. The T2DM mouse model was established with a high-fat diet with two streptozotocin injections (50 mg/kg/body wt) in C57BL/6 female mice. The diabetic mice underwent treadmill exercises (5 days/week at 7-11 m/min for 60 min/day) for 8 weeks. The data showed that diabetes upregulated miR-150 expression through oxidative stress and suppressed FNDC5/Irisin by binding to its 3'-untranslated region. The decreased level of irisin further triggers the pyroptosis response in diabetic bone tissue. EX or N-acetyl cysteine or anti-miRNA-150 transfection in T2DM mice restored FNDC5/Irisin expression and bone formation. Furthermore, EX or recombinant irisin administration prevented T2DM-Induced hyperglycemia and improved glucose intolerance in diabetic mice. Furthermore, osteoblastic knockdown of Nlrp3 silencing (si-Nlrp3) or pyroptosis inhibitor (Ac-YVADCMK [AYC]) treatment restores bone mineralization in diabetic mice. Micro-computed tomography scans and mechanical testing revealed that trabecular bone microarchitecture and bone mechanical properties were improved after EX in diabetic mice. Irisin, either induced by skeleton or daily EX or directly administered, prevents bone loss by mitigating inflammasome-associated pyroptosis signaling in diabetic mice. This study demonstrates that EX-induced skeletal irisin ameliorates diabetes-associated glucose intolerance and bone loss and possibly provides a mechanism of its effects on metabolic osteoporosis.

Association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms with vitamin B12 deficiency and adverse perinatal outcomes among pregnant women of rural South India - a cross sectional longitudinal study

OBJECTIVES

To determine the occurrence of MTHFR gene polymorphisms and to study their association with vitamin B12 deficiency and adverse perinatal outcomes among a cohort of pregnant women from Kaniyambadi block, Tamil Nadu.

METHODS

120 consecutive pregnant women who were ≤20 weeks of gestational age from the 82 villages of Kaniyambadi block were recruited. Genomic DNA was isolated from the peripheral blood. PCR amplification was done followed by Sangers sequencing. Maternal and neonatal outcomes were extracted. Data was entered and analysed.

RESULTS

Our study found the occurrence of c.1298A>C variant in homozygous state in 14.2% and c.677C>T heterozygous state in 15%. Sanger sequencing of exon 7 identified another pathogenic variant c.1262G>T in heterozygous state in two of them. Both the mothers who harboured that variant had preterm delivery and one of them gave birth to a low-birth-weight neonate. In the entire cohort, 5% of the mothers had abortion, 4.2% of them had preterm delivery and 8.8% of the neonates had low birth weight. Presence of c.1298A>C or c.677C>T variants were associated with vitamin B12 deficiency [Pearson Chi squared value (χ²)=7.9 and 7.6 respectively; p=0.02]. Heterozygous pathogenic variant c.1262G>T was associated with both adverse maternal [χ²=11.5; p=0.001] and neonatal [χ²=18.3; p=0.009] outcomes.

CONCLUSIONS

MTHFR gene polymorphisms could be associated with several adverse perinatal outcomes and vitamin B12 deficiency. Further larger studies are needed to prove the pathogenicity of c.1262G>T variant on pregnancy.

Comprehensive analysis of cuproptosis-related lncRNAs to predict prognosis and immune infiltration characteristics in colorectal cancer

Background: Cuproptosis is a novel form of cell death discovered in recent. A great quantity of researches has confirmed the close relationships and crucial roles between long non-coding RNAs (lncRNAs) with the progression of colorectal cancer (CRC). However, the relationship between cuproptosis and lncRNAs remains unclear in CRC.

Methods: 1,111 co-expressed lncRNAs with 16 cuproptosis regulators were retrieved from CRC samples of The Cancer Genome Atlas (TCGA) database. Through univariate Cox and least absolute shrinkage and selection operator regression analysis, a prognosis model was constructed with 15 lncRNAs. The Kaplan-Meier, receiver operating characteristic curve, C-index and principal component analysis identified the prognostic power. Furthermore, a cuproptosis-related cluster was generated based on the 15 lncRNAs by unsupervised methods. The correlations between the cuproptosis-related signatures with immune cell infiltration and anti-tumor therapy were explored by multiple algorithms.

Results: A risk score and nomogram with great prediction ability were constructed for CRC prognosis evaluation. The immune activate pathways, immune infiltration cells, immune functions, immune score and immune activation genes were remarkably enriched in the high risk group. The cuproptosis-related cluster was generated, of which the cluster 2 showed longer overall survival. The immune cell infiltration analysis indicated the similar results of cluster 2 with the high risk group, implying a significant marker for “hot tumor.” The cluster 2 also presented high expression of immune checkpoint molecules, MSI-H status and higher susceptibility to multiple immunotherapy drugs.

Conclusion: We appraised a novel cuproptosis-related prognosis model and molecular signature associated with prognosis, immune infiltration and immunotherapy. The identification of cuproptosis-related lncRNAs improved our understanding of immune infiltration and provided a significant marker for prognosis and immunotherapy in CRC.

Non-canonical NF-κB contributes to endothelial pyroptosis and atherogenesis dependent on IRF-1

Cell inflammation and death are closely linked processes contributing to endothelial dysfunction, which plays a critical role in atherogenesis. Activation of the NLRP3 inflammasome causes pyroptosis, the Gasdermin D (GSDMD)-mediated inflammatory cell death. The non-canonical NF-κB pathway has been implicated in inflammation; however, its role in NLRP3 inflammasome-mediated endothelial dysfunction has not been investigated. This study investigated a role for the non-canonical NF-κB pathway in regulating endothelial pyroptosis as it relates to atherogenesis. Immunohistochemistry indicated inflammasome activation in the endothelial cells (EC) of human atherosclerotic arteries. Flow cytometry and Western blot analysis revealed that oxidized low-density lipoprotein (oxLDL) activated the NLRP3 inflammasome, concomitant with the activation of non-canonical NF-κB in primary human aortic EC. Interference of NF-κB inducing kinase (NIK), the key regulator of the non-canonical pathway, significantly attenuated oxLDL- or LPS/ATP-induced NLRP3 inflammasome activation, pyroptosis, IL-1β, and IL-18 secretion. In contrast, overexpression of NIK exacerbated these responses. Chromatin immunoprecipitation revealed that activation of the non-canonical NF-κB pathway upregulated the transcription factor IRF-1 through RelB/p52 binding to its promoter region at -782/-770. In addition to the known target CASP1, RNA sequencing further identified GSDMD as a target gene of IRF-1. IRF-1 but not RelB/p52 interacted with the GSDMD promoter at -526/-515 and the CASP1 promoter at -11/10 to promote the expression and CASP1-mediated activation of GSDMD. Consistent with the observations in cultured endothelium, endothelial-specific deficiency of NIK or IRF-1 attenuated atherosclerosis in high-fat diet-fed Apoe-null mice. These data demonstrate that the non-canonical NF-κB pathway contributes to NLRP3 inflammasome-mediated endothelial pyroptosis and the development of atherosclerosis through GSDMD activation in a manner dependent on IRF-1. Further investigation may facilitate the identification of specific therapeutic targets for atherosclerotic heart diseases.

Epigenetic Mechanisms Involved in Inflammaging-Associated Hypertension

PURPOSE OF REVIEW

This review summarizes the involvement of inflammaging in vascular damage with focus on the epigenetic mechanisms by which inflammaging-induced hypertension is triggered.

RECENT FINDINGS

Inflammaging in hypertension is a complex condition associated with the production of inflammatory mediators by the immune cells, enhancement of oxidative stress, and tissue remodeling in vascular smooth muscle cells and endothelial cells. Cellular processes are numerous, including inflammasome assembly and cell senescence which may involve mitochondrial dysfunction, autophagy, DNA damage response, dysbiosis, and many others. More recently, a series of noncoding RNAs, mainly microRNAs, have been described as possessing epigenetic actions on the regulation of inflammasome-related hypertension, emerging as a promising therapeutic strategy. Although there are a variety of pharmacological agents that effectively regulate inflammaging-related hypertension, a deeper understanding of the epigenetic events behind the control of vessel deterioration is needed for the treatment or even to prevent the disease onset.

The crosstalk among autophagy, apoptosis, and pyroptosis in cardiovascular disease

In recent years, the mechanism of cell death has become a hotspot in research on the pathogenesis and treatment of cardiovascular disease (CVD). Different cell death modes, including autophagy, apoptosis, and pyroptosis, are mosaic with each other and collaboratively regulate the process of CVD. This review summarizes the interaction and crosstalk of key pathways or proteins which play a critical role in the entire process of CVD and explores the specific mechanisms. Furthermore, this paper assesses the interrelationships among these three cell deaths and reviews how they regulate the pathogenesis of CVD. By understanding how these three cell death modes go together we can learn about the pathogenesis of CVD, which will enable us to identify new targets for preventing, controlling, and treating CVD. It will not only reduce mortality but also improve the quality of life.

Molecular mechanisms and roles of pyroptosis in acute lung injury

ABSTRACT

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), which are characterized by excessive inflammation and accompanied by diffuse injury of alveoli, can result in severe respiratory failures. The morbidity and mortality of patients remain high because the major treatments for ALI/ARDS are mainly supportive due to the lack of effective therapies. Numerous studies have demonstrated that the aggravation of coronavirus disease 2019 (COVID-19) leads to severe pneumonia and even ARDS. Pyroptosis, a biological process identified as a type of programed cell death, is mainly triggered by inflammatory caspase activation and is directly meditated by the gasdermin protein family, as well as being associated with the secretion and release of pro-inflammatory cytokines. Clinical and experimental evidence corroborates that pyroptosis of various cells in the lung, such as immune cells and structural cells, may play an important role in the pathogenesis of "cytokine storms" in ALI/ARDS, including those induced by COVID-19. Here, with a focus on ALI/ARDS and COVID-19, we summarized the recent advances in this field and proposed the theory of an inflammatory cascade in pyroptosis to identify new targets and pave the way for new approaches to treat these diseases.

A novel cuproptosis-related molecular pattern and its tumor microenvironment characterization in colorectal cancer

Cuproptosis, or copper-induced cell death, has been reported as a novel noncanonical form of cell death in recent times. However, the potential roles of cuproptosis in the alteration of tumor clinicopathological features and the formation of a tumor microenvironment (TME) remain unclear. In this study, we comprehensively analyzed the cuproptosis-related molecular patterns of 1,274 colorectal cancer samples based on 16 cuproptosis regulators. The consensus clustering algorithm was conducted to identify cuproptosis-related molecular patterns and gene signatures. The ssGSEA and ESTIMATE algorithms were used to evaluate the enrichment levels of the infiltrated immune cells and tumor immune scores, respectively. The cuproptosis score was established to assess the cuproptosis patterns of individuals with principal component analysis algorithms based on the expression of cuproptosis-related genes. Three distinct cuproptosis patterns were confirmed and demonstrated to be associated with distinguishable biological processes and clinical prognosis. Interestingly, the three cuproptosis patterns were revealed to be consistent with three immune infiltration characterizations: immune-desert, immune-inflamed, and immune-excluded. Enhanced survival, activation of immune cells, and high tumor purity were presented in patients with low cuproptosisScore, implicating the immune-inflamed phenotype. In addition, low scores were linked to high tumor mutation burden, MSI-H and high CTLA4 expression, showing a higher immune cell proportion score (IPS). Taken together, our study revealed a novel cuproptosis-related molecular pattern associated with the TME phenotype. The formation of cuproptosisScore will further strengthen our understanding of the TME feature and instruct a more personalized immunotherapy schedule in colorectal cancer.

Pinocembrin suppresses oxidized low-density lipoprotein-triggered NLRP3 inflammasome/GSDMD-mediated endothelial cell pyroptosis through an Nrf2-dependent signaling pathway

Pinocembrin (Pin) has been confirmed to exert anti-inflammatory and antiatherosclerotic effects. Here we have explored whether and how Pin would protect vascular endothelial cells against pyroptosis elicited by the exposure to oxidized low density lipoprotein (oxLDL). Our results showed that Pin preconditioning dose-dependently suppressed oxLDL-stimulated HUVEC injury and pyroptosis, which were manifested by improved cell viability, lower lactate dehydrogenase (LDH) levels and DNA damage as well as decreased expression of pyroptosis-related markers, such as NOD-like receptor pyrin domain-containing 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), pro-Caspase-1, cleaved Caspase-1, N-terminus of Gasdermin D-N (GSDMD-N), pro-interleukins-1β (pro-IL-1β), IL-1β and inflammatory cytokines (IL-18 and IL-1β). All of the effects were similar to those of MCC950 (an NLRP3 inhibitor). As expected, Pin distinctly activated the Nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidative signaling pathway assessed through increased expressions of Nrf2, heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1). Furthermore, after transfection with small interfering RNA of Nrf2, the inhibitory effects of Pin on oxLDL-triggered NLRP3 inflammasome/GSDMD-mediated pyroptosis and oxidative stress in HUVECs were weakened. Additionally, Pin up-regulated Nrf2/HO-1 axis and down-regulated NLRP3 inflammasome/GSDMD-mediated pyroptosis signals in Apoe^-/- mice fed with high fat diet. These results contribute to the understanding of the anti-pyroptosis mechanisms of Pin and provide a reference for future research on the anti-atherosclerotic effect of Pin.

Pyroptosisin periodontitis: From the intricate interaction with apoptosis, NETosis, and necroptosis to the therapeutic prospects

Periodontitis is highly prevalent worldwide. It is characterized by periodontal attachment and alveolar bone destruction, which not only leads to tooth loss but also results in the exacerbation of systematic diseases. As such, periodontitis has a significant negative impact on the daily lives of patients. Detailed exploration of the molecular mechanisms underlying the physiopathology of periodontitis may contribute to the development of new therapeutic strategies for periodontitis and the associated systematic diseases. Pyroptosis, as one of the inflammatory programmed cell death pathways, is implicated in the pathogenesis of periodontitis. Progress in the field of pyroptosis has greatly enhanced our understanding of its role in inflammatory diseases. This review first summarizes the mechanisms underlying the activation of pyroptosis in periodontitis and the pathological role of pyroptosis in the progression of periodontitis. Then, the crosstalk between pyroptosis with apoptosis, necroptosis, and NETosis in periodontitis is discussed. Moreover, pyroptosis, as a novel link that connects periodontitis with systemic disease, is also reviewed. Finally, the current challenges associated with pyroptosis as a potential therapeutic target for periodontitis are highlighted.