Selenium deficiency exacerbates ROS/ER stress mediated pyroptosis and ferroptosis induced by bisphenol A in chickens thymus.

Bisphenol A (BPA) is an industrial pollutant that can cause immune impairment. Selenium acts as an antioxidant, as selenium deficiency often accompanies oxidative stress, resulting in organ damage. This study is the first to demonstrate that BPA and/or selenium deficiency induce pyroptosis and ferroptosis-mediated thymic injury in chicken and chicken lymphoma cell (MDCC-MSB-1) via oxidative stress-induced endoplasmic reticulum (ER) stress. We established a broiler chicken model of BPA and/or selenium deficiency exposure and collected thymus samples as research subjects after 42 days. The results demonstrated that BPA or selenium deficiency led to a decrease in antioxidant enzyme activities (T-AOC, CAT, and GSH-Px), accumulation of peroxides (H2O2 and MDA), significant upregulation of ER stress-related markers (GRP78, IER 1, PERK, EIF-2α, ATF4, and CHOP), a significant increase in iron ion levels, significant upregulation of pyroptosis-related gene (NLRP3, ASC, Caspase1, GSDMD, IL-18 and IL-1ß), significantly increase ferroptosis-related genes (TFRC, COX2) and downregulate GPX4, HO-1, FTH, NADPH. In vitro experiments conducted in MDCC-MSB-1 cells confirmed the results, demonstrating that the addition of antioxidant (NAC), ER stress inhibitor (TUDCA) and pyroptosis inhibitor (Vx765) alleviated oxidative stress, endoplasmic reticulum stress, pyroptosis, and ferroptosis. Overall, this study concludes that the combined effects of oxidative stress and ER stress mediate pyroptosis and ferroptosis in chicken thymus induced by BPA exposure and selenium deficiency.

Resveratrol improved mitochondrial biogenesis by activating SIRT1/PGC-1α signal pathway in SAP.

NLRP3 inflammasomes- pyroptosis axis is activated by microcirculation dysfunction and touched off severe acute pancreatitis (SAP). Activation of PGC-1α can improve microcirculation dysfunction by promoting mitochondrial biogenesis. Resveratrol (RSV), one typical SIRT1 agonist, possesses the ability of alleviating SAP and activing PGC-1α. Therefore, the study was designated to explore whether the protective effect of RSV in SAP was though suppressing NLRP3 inflammasomes- pyroptosis axis via advancing SIRT1/PGC-1α-dependent mitochondrial biogenesis. The models of SAP were induced by treating with sodium taurodeoxycholate in rats and AR42J cells. The pathological injury, water content (dry/wet ratio) and microcirculation function of pancreas, activity of lipase and amylase were used to evaluate pancreatic damage. The expression of inflammatory cytokine was measured by ELISA and RT-PCR. The damage of mitochondrial was evaluated by measuring the changes in Mitochondrial Membrane Potential (ΔΨm), mitochondrial ROS, ATP content and MDA as well as relocation of mtDNA and the activity of SOD and GSH. The expressions of NLRP3 inflammasomes- pyroptosis axis proteins were detected by Western blotting as well as SIRT1/PGC-1α/NRF1/TFAM pathway protein. Moreover, the modification of PGC-1α was measured by co-immunoprecipitation. The results displayed that RSV can significantly improve the damage of pancreas and mitochondrial, decrease the expression of pro-inflammatory factor and the activation of NLRP3 inflammasomes- pyroptosis axis, promote the expression of an-inflammatory factor and the deacetylation of PGC-1α together with facilitating SIRT1/PGC-1α-mediating mitochondrial biogenesis. Therefore, the protective effect of RSV in SAP is though inactivation of NLRP3 inflammasomes- pyroptosis axis via promoting mitochondrial biogenesis in a SIRT1/PGC-1α-dependent manner.

Pterostilbene Induces Pyroptosis in Breast Cancer Cells through Pyruvate Kinase 2/Caspase-8/Gasdermin C Signaling Pathway.

The incidence and mortality of breast cancer increase year by year, and it is urgent to find high-efficiency and low-toxicity anti-cancer drugs. Pterostilbene (PTE) is a natural product with antitumor activity, but the specific antitumor mechanism is not very clear. Aerobic glycolysis is the main energy supply for cancer cells. Pyroptosis is an inflammatory, programmed cell death. The aim of this study was to investigate the effect of PTE on glycolysis and pyroptosis in EMT6 and 4T1 cells and the specific mechanism, and to elucidate the role of pyruvate kinase 2 (PKM2), a key enzyme in glycolysis, in the antitumor role of PTE. Our study suggested that PTE induced pyroptosis by inhibiting tumor glycolysis. PKM2 played an important role in both the inhibition of glycolysis and the induction of pyroptosis by PTE.

Neisseria meningitidis activates pyroptotic pathways in a mouse model of meningitis: role of a two-partner secretion system.

There is evidence that in infected cells in vitro the meningococcal HrpA/HrpB two-partner secretion system (TPS) mediates the exit of bacteria from the internalization vacuole and the docking of bacteria to the dynein motor resulting in the induction of pyroptosis. In this study we set out to study the role of the HrpA/HrpB TPS in establishing meningitis and activating pyroptotic pathways in an animal model of meningitis using a reference serogroup C meningococcal strain, 93/4286, and an isogenic hrpB knockout mutant, 93/4286ΩhrpB. Survival experiments confirmed the role of HrpA/HrpB TPS in the invasive meningococcal disease. In fact, the ability of the hrpB mutant to replicate in brain and spread systemically was impaired in mice infected with hrpB mutant. Furthermore, western blot analysis of brain samples during the infection demonstrated that: i. N. meningitidis activated canonical and non-canonical inflammasome pyroptosis pathways in the mouse brain; ii. the activation of caspase-11, caspase-1, and gasdermin-D was markedly reduced in the hrpB mutant; iii. the increase in the amount of IL-1ß and IL-18, which are an important end point of pyroptosis, occurs in the brains of mice infected with the wild-type strain 93/4286 and is strongly reduced in those infected with 93/4286ΩhrpB. In particular, the activation of caspase 11, which is triggered by cytosolic lipopolysaccharide, indicates that during meningococcal infection pyroptosis is induced by intracellular infection after the exit of the bacteria from the internalizing vacuole, a process that is hindered in the hrpB mutant. Overall, these results confirm, in an animal model, that the HrpA/HrpB TPS plays a role in the induction of pyroptosis and suggest a pivotal involvement of pyroptosis in invasive meningococcal disease, paving the way for the use of pyroptosis inhibitors in the adjuvant therapy of the disease.

Apelin-13's Actions in Controlling Hypertension-Related Cardiac Hypertrophy and the Expressions of Inflammatory Cytokines.

As a key molecule for improving cardiovascular diseases, Apelin-13 was surveyed in this work to explain its actions in controlling inflammation, pyroptosis, and myocardial hypertrophy. First, mouse models with myocardial hypertrophy were established. Then, assessments were made on the pathological variation in the heart of mouse, on the cardiac functions, as well as on the expressions of cardiac hypertrophy markers (ß-MHC, ANP, and BNP), inflammatory factors (TNF-α, COX2, IL-6, ICAM-1, and VCAM-1), myocardial cell pyroptosis markers (NLRP3, ASC, c-caspase-1, and GSDMD-N), and Hippo pathway proteins (p-YAP, YAP, LATS1, and p-LATS1) by HE staining, echocardiography scanning, and western blot tests separately. The expressions of such inflammatory factors as in myocardial tissue were acquired by ELISA. After inducing the phenotype of H9c2 cell hypertrophy by noradrenaline, we used CCK-8 kits to know about the activity of H9c2 cells treated with Apelin-13, and performed ɑ-actinin staining to measure the changes in volumes of such cells. As unraveled through this work, Apelin-13 refrained the activation of the Hippo pathway, which in turn attenuated the hypertrophy, inflammation, and pyroptosis of myocardial tissue and H9c2 cells. Hence, Apelin-13 can be considered as a target for hypertension treatment.

Intermetallics triggering pyroptosis and disulfidptosis in cancer cells promote anti-tumor immunity.

Pyroptosis, an immunogenic programmed cell death, could efficiently activate tumor immunogenicity and reprogram immunosuppressive microenvironment for boosting cancer immunotherapy. However, the overexpression of SLC7A11 promotes glutathione biosynthesis for maintaining redox balance and countering pyroptosis. Herein, we develop intermetallics modified with glucose oxidase (GOx) and soybean phospholipid (SP) as pyroptosis promoters (Pd2Sn@GOx-SP), that not only induce pyroptosis by cascade biocatalysis for remodeling tumor microenvironment and facilitating tumor cell immunogenicity, but also trigger disulfidptosis mediated by cystine accumulation to further promote tumor pyroptosis in female mice. Experiments and density functional theory calculations show that Pd2Sn nanorods with an intermediate size exhibit stronger photothermal and enzyme catalytic activity compared with the other three morphologies investigated. The peroxidase-mimic and oxidase-mimic activities of Pd2Sn cause potent reactive oxygen species (ROS) storms for triggering pyroptosis, which could be self-reinforced by photothermal effect, hydrogen peroxide supply accompanied by glycometabolism, and oxygen production from catalase-mimic activity of Pd2Sn. Moreover, the increase of NADP+/NADPH ratio induced by glucose starvation could pose excessive cystine accumulation and inhibit glutathione synthesis, which could cause disulfidptosis and further augment ROS-mediated pyroptosis, respectively. This two-pronged treatment strategy could represent an alternative therapeutic approach to expand anti-tumor immunotherapy.

Determining the Feasibility of a Cadmium Exposure Model to Activate the Inflammatory Arm of PANoptosis in Murine Monocytes.

A prevalence of cigarette smoking can cause the accumulation of cadmium (Cd2+) in the lungs, kidneys, and blood. The effects of exposure can cause multiple chronic disease types to emerge in the affected organ systems. The only moderately effective therapeutic option is chelation therapy; the health risks associated with this therapy have caused much criticism. The disease types associated with Cd2+ toxicity have inflammatory components and greatly impact innate immunity. These factors are affected at the cellular level and cause pathways like apoptosis, pyroptosis, and necroptosis. A development in understanding these pathways stipulates that these three pathways act as one complex of pathways, known together as PANoptosis. The inflammatory mechanisms of PANoptosis are particularly interesting in Cd2+ toxicity due to its inflammatory effects. Proteins in the gasdermin family act to release inflammatory cytokines, like interleukin-1ß, into the extracellular environment. Cytokines cause inflammatory disease pathologies like fibrosis and cancer. RAW 264.7 monocytes are key in the murine immune system and provide an excellent model to investigate Cd2+ toxicity. Exposure of 0-15 µM CdCl2 was sufficient to increase expression of cleaved gasdermin D (GSDMD) and gasdermin E (GSDME) in this cell type. Cd2+ also exhibits a dose-dependent cytotoxicity in this cell type.

Co-delivery of polyphyllin II and IR780 PLGA nanoparticles induced pyroptosis combined with photothermal to enhance hepatocellular carcinoma immunotherapy.

The clinical efficacy of immunotherapy for hepatocellular carcinoma (HCC) is significantly limited by the low immunogenicity of the tumor. Recent studies have revealed that both pyroptosis and photothermal therapy can effectively induce tumor immunogenic cell death (ICD) in liver cancer cells. Polyphyllin II (PPII), the major active component of Rhizoma Paridis, has been demonstrated for the first time to induce pyroptosis in tumor cells, while IR780 is activated by 808 nm laser to transform light energy into heat energy, effectively eliminating tumor cells. However, both PPII and IR780 are afflicted with challenges such as low solubility and poor targeting, significantly limiting their utilization. To address these problems, the pyroptosis inducer PPII and photosensitizer IR780 were co-loaded in PLGA nanoparticles by precipitation method, and the aptamer AS1411 was modified on the surface of nanoparticles to construct the targeting nanoparticles (Apt/PPII/IR780-NPs). The nanoparticles exhibit a pH/NIR dual-response intelligent release feature, which realizes the targeted and controlled release of drugs in tumor site. Furthermore, it can rapidly release PPII to induce cell pyroptosis under laser irradiation, combining with IR780-based photothermal therapy exert a significant synergistic anti-tumor effect in vitro and in vivo. This process not only promotes maturation of DCs and activates effector T cells, thereby initiating adaptive immunity, but also generates enduring and effective immune memory. In addition, Apt/PPII/IR780-NPs significantly improved the Anti-PD-1 efficacy. In summary, chemo-photothermal therapy based on Apt/PPII/IR780-NPs can significantly enhance tumor ICD, which provides a promising new strategy for HCC immunotherapy.

[NLRC3 alleviates immune inflammatory response induced by macrophage pyroptosis in patients with rheumatoid arthritis by inhibiting STING signaling pathway].

Objective To explore the role and potential mechanism of caspase activation and recruitment domain-containing nucleotide-binding oligomerization domain-like receptor 3 (NLRC3) in the immune inflammatory response induced by macrophage pyroptosis in patients with rheumatoid arthritis (RA). Methods Fifty RA patients and ten healthy volunteers were selected according to inclusion criteria. Peripheral blood macrophages were extracted and divided into six groups: normal control(NC), RA macrophage model (RA-MC), RA-MC with NLRC3 overexpression, RA-MC with NLRC3 knockdown, RA-MC with STING overexpression, and RA-MC with STING knockdown groups. Macrophage pyroptosis was observed using transmission electron microscopy. The mRNA expressions of NLRC3, STING, caspase-1, and GSDMD were detected using RT-qPCR. interleukin 1ß (IL-1ß) and IL-18 levels in cell supernatants were measured using ELISA. Results Compared to the NC group, the RA-MC group showed characteristics of pyroptosis. Compared to the RA-MC group, the groups of RA-MC with NLRC3 overexpression and RA-MC with STING knockdown showed improved pyroptosis, while the groups of RA-MC with NLRC3 knockdown and RA-MC with STING overexpression demonstrated exacerbated pyroptosis. Compared to the NC group, the RA-MC group showed increased mRNA expression levels of STING, caspase-1 and GSDMD, as well as increased levels of the inflammatory cytokines IL-1ß and IL-18, but decreased NLRC3 mRNA expression level. Compared to the RA-MC group, the groups of RA-MC with NLRC3 overexpression and RA-MC with STING knockdown showed reduced mRNA expression levels of caspase-1 and GSDMD, as well as reduced inflammatory factors, while the groups of RA-MC with NLRC3 knockdown and RA-MC with STING overexpression had opposite results. Compared to the RA-MC group, the group of RA-MC with NLRC3 overexpression showed a decreased STING mRNA expression level, while the group of RA-MC with NLRC3 knockdown demonstrated an increased level. Conclusion NLRC3 can inhibit the STING signaling pathway, reduce pyroptosis proteins caspase-1 and GSDMD, antagonize macrophage pyroptosis, and lower the levels of inflammatory cytokines IL-1ß and IL-18, thereby alleviating the immune inflammatory response in RA patients.

[Huangqi Glycoprotein improves myocardial injury in rats with adjuvant arthritis by interfering with lncRNA GAS5/miR-21/TLR4 signaling axis to inhibit pyroptosis].

Objective To investigate the effect and mechanism of Huangqi glycoprotein (HQGP) on myocardial injury in rats with adjuvant arthritis (AA) based on the long non-coding RNA growth arrest-specific transcript 5/microRNA-21/Toll-like receptor 4 (lncRNA GAS5/miR-21/TLR4) signal axis. Methods SD rats were randomized into normal control, model, methotrexate (MTX) and HQGP groups, with 6 rats in each group. The AA rat model was established, and the drug was administered on the 19th day after the model was established, for 4 consecutive weeks. The degree of toe swelling and the arthritis index (AI) of AA rats in each group were measured. The pathological changes of rat myocardial tissue were observed by HE staining, and the changes in the ultrastructure of the myocardial tissue and the situation of pyroptotic vesicles were observed by transmission electron microscope. The levels of serum interleukin 6 (IL-6), IL-18, IL-1ß and tumor necrosis factor α (TNF-α) were detected by ELISA. The release of lactate dehydrogenase (LDH) in myocardial tissue was detected by kit. Real-time quantitative PCR was used to detect the mRNA expression of nuclear factor-kappa B p65 (NF-κB p65), cysteine aspartate specific proteinase 1 (caspase-1), nucleotide binding oligomerization domain like receptor family pyrin domain containing 3 (NLRP3), gasdermin D (GSDMD), and molecules in the lncRNA GAS5/miR-21/TLR4 signaling axis in the myocardial tissue. The protein levels of TLR4, NF-κB p65, caspase-1, NLRP3 and GSDMD in myocardial tissue were detected by Western blot. Results Compared with the normal control group, the toe swelling and AI of the model group rats were significantly increased. The myocardial fibers of rats dissolved and broken, the structure of sarcomere was blurred, the arrangement of myocardial fibers was disordered, there was inflammatory cell infiltration between tissues, the mitochondrial cristae were significantly broken and sparse, and the number of pyroptotic vesicles increased. The expression of serum pro-inflammatory cytokines IL-6, IL-18, IL-1ß and TNF-α increased significantly. In myocardial tissue, the expression of GAS5 reduced significantly, the expression of miR-21 increased significantly, the release of LDH, and the mRNA and protein levels of TLR4, NF-κB p65, caspase-1, NLRP3 and GSDMD increased significantly. Compared with the model group, the toe swelling, AI, and the pathological status of myocardial tissue in the HQGP group rats were improved significantly. The expressions of serum IL-6, IL-18, IL-1ß and TNF-α reduced significantly. In myocardial tissue, the expression of GAS5 increased significantly, the expression of miR-21 decreased significantly, the release of LDH, the mRNA and protein levels of TLR4, NF-κB p65, caspase-1 and NLRP3 decreased significantly, and the mRNA expression of GSDMD reduced while the protein level significantly reduced. Conclusion HQGP improves myocardial injury in AA rats by inhibiting miR-21/TLR4 signalling through up-regulation of lncRNA GAS5, inhibiting pyroptosis, and reducing pro-inflammatory cytokine expression.

Deubiquitinase USP5 regulates RIPK1 driven pyroptosis in response to myocardial ischemic reperfusion injury.

BACKGROUND: Gasdermin D (GSDMD) mediated pyroptosis plays a significant role in the pathophysiology of myocardial ischemia/reperfusion (I/R) injury. However, the precise mechanisms regulating pyroptosis remain unclear. In the study, we aimed to investigate the underlying mechanism of pyroptosis in myocardial I/R injury. METHODS: In the present study, we analyzed the effects of USP5 on the RIPK1 kinase activity mediated pyroptosis in vitro after H/R (hypoxia/reoxygenation) and in vivo in a MI/R mouse model. TTC and Evan's blue dye, Thioflavin S and immunohistochemistry staining were performed in wild-type, RIPK1flox/flox Cdh5-Cre and USP5 deficiency mice. CMEC cells were transfected with si-USP5. HEK293T cells were transfected with USP5 and RIPK1 overexpression plasmid or its mutants. The levels of USP5, RIPK1, Caspase-8, FADD and GSDMD were determined by Western blot. Protein interactions were evaluated by immunoprecipitation. The protein colocalization in cells was monitored using a confocal microscope. RESULTS: In this study, our data demonstrate that RIPK1 is essential for limiting cardiac endothelial cell (CMEC) pyroptosis mediated by caspase-8 in response to myocardial I/R. Additionally, we investigate the role of ubiquitin-specific protease 5 (USP5) as a deubiquitinase for RIPK1. Mechanistically, USP5 interacts with RIPK1, leading to its deubiquitination and stabilization. CONCLUSIONS: These findings offer new insights into the role of USP5 in regulating RIPK1-induced pyroptosis.

Sirtuin 1 in regulating the p53/glutathione peroxidase 4/gasdermin D axis in acute liver failure.

In this editorial, we comment on the article by Zhou et al. The study reveals the connection between ferroptosis and pyroptosis and the effect of silent information regulator sirtuin 1 (SIRT1) activation in acute liver failure (ALF). ALF is characterized by a sudden and severe liver injury resulting in significant hepatocyte damage, often posing a high risk of mortality. The predominant form of hepatic cell death in ALF involves apoptosis, ferroptosis, autophagy, pyroptosis, and necroptosis. Glutathione peroxidase 4 (GPX4) inhibition sensitizes the cell to ferroptosis and triggers cell death, while Gasdermin D (GSDMD) is a mediator of pyroptosis. The study showed that ferroptosis and pyroptosis in ALF are regulated by blocking the p53/GPX4/GSDMD pathway, bridging the gap between the two processes. The inhibition of p53 elevates the levels of GPX4, reducing the levels of inflammatory and liver injury markers, ferroptotic events, and GSDMD-N protein levels. Reduced p53 expression and increased GPX4 on deletion of GSDMD indicated ferroptosis and pyroptosis interaction. SIRT1 is a NAD-dependent deacetylase, and its activation attenuates liver injury and inflammation, accompanied by reduced ferroptosis and pyroptosis-related proteins in ALF. SIRT1 activation also inhibits the p53/GPX4/GSDMD axis by inducing p53 acetylation, attenuating LPS/D-GalN-induced ALF.

The role of pyroptosis in the occurrence and development of pregnancy-related diseases.

Pyroptosis is a form of programmed cell death that is crucial in the development of various diseases, including autoimmune diseases, atherosclerotic diseases, cancer, and pregnancy complications. In recent years, it has gained significant attention in national and international research due to its association with inflammatory immune overactivation and its involvement in pregnancy complications such as miscarriage and preeclampsia (PE). The mechanisms discussed include the canonical pyroptosis pathway of gasdermin activation and pore formation (caspase-1-dependent pyroptosis) and the non-canonical pyroptosis pathway (cysteoaspartic enzymes other than caspase-1). These pathways work on various cellular and factorial levels to influence normal pregnancy. This review aims to summarize and analyze the pyroptosis pathways associated with abnormal pregnancies and pregnancy complications. The objective is to enhance pregnancy outcomes by identifying various targets to prevent the onset of pyroptosis.

Targeting both ferroptosis and pyroptosis may represent potential therapies for acute liver failure.

In this editorial, we comment on the article published in the recent issue of the World Journal of Gastroenterology. Acute liver failure (ALF) is a fatal disease that causes uncontrolled massive hepatocyte death and rapid loss of liver function. Ferroptosis and pyroptosis, cell death forms that can be initiated or blocked concurrently, can play significant roles in developing inflammation and various malignancies. However, their roles in ALF remain unclear. The article discovered the positive feedback between ferroptosis and pyroptosis in the progression of ALF, and revealed that the silent information regulator sirtuin 1 (SIRT1) inhibits both pathways through p53, dramatically reducing inflammation and protecting hepatocytes. This suggests the potential use of SIRT1 and its downstream molecules as therapeutics for ALF. Thus, we will discuss the role of ferroptosis and pyroptosis in ALF and the crosstalk between these cell death mechanisms. Additionally, we address potential treatments that could alleviate ALF by simultaneously inhibiting both cell death pathways, as well as examples of SIRT1 activators being used as disease treatment strategies, providing new insights into the therapy of ALF.

CircSSR1 regulates pyroptosis of pulmonary artery smooth muscle cells through parental protein SSR1 mediating endoplasmic reticulum stress.

INTRODUCTION: Pyroptosis, inflammatory necrosis of cells, is a programmed cell death involved in the pathological process of diseases. Endoplasmic reticulum stress (ERS), as a protective stress response of cell, decreases the unfold protein concentration to inhibit the unfold protein agglutination. Whereas the relationship between endoplasmic reticulum stress and pyroptosis in pulmonary hypertension (PH) remain unknown. Previous evident indicated that circular RNA (circRNA) can participate in several biological process, including cell pyroptosis. However, the mechanism of circRNA regulate pyroptosis of pulmonary artery smooth muscle cells through endoplasmic reticulum stress still unclear. Here, we proved that circSSR1 was down-regulate expression during hypoxia in pulmonary artery smooth muscle cells, and over-expression of circSSR1 inhibit pyroptosis both in vitro and in vivo under hypoxic. Our experiments have indicated that circSSR1 could promote host gene SSR1 translation via m6A to activate ERS leading to pulmonary artery smooth muscle cell pyroptosis. In addition, our results showed that G3BP1 as upstream regulator mediate the expression of circSSR1 under hypoxia. These results highlight a new regulatory mechanism for pyroptosis and provide a potential therapy target for pulmonary hypertension. METHODS: RNA-FISH and qRT-PCR were showed the location of circSSR1 and expression change. RNA pull-down and RIP verify the circSSR1 combine with YTHDF1. Western blotting, PI staining and LDH release were used to explore the role of circSSR1 in PASMCs pyroptosis. RESULTS: CircSSR1 was markedly downregulated in hypoxic PASMCs. Knockdown CircSSR1 inhibited hypoxia induced PASMCs pyroptosis in vivo and in vitro. Mechanistically, circSSR1 combine with YTHDF1 to promote SSR1 protein translation rely on m6A, activating pyroptosis via endoplasmic reticulum stress. Furthermore, G3BP1 induce circSSR1 degradation under hypoxic. CONCLUSION: Our findings clarify the role of circSSR1 up-regulated parental protein SSR1 expression mediate endoplasmic reticulum stress leading to pyroptosis in PASMCs, ultimately promoting the development of pulmonary hypertension.

Endothelial pyroptosis-driven microglial activation in choroid plexus mediates neuronal apoptosis in hemorrhagic stroke rats.

BACKGROUND: Spontaneous intracerebral hemorrhage (ICH) is associated with alarmingly high rates of disability and mortality, and current therapeutic options are suboptimal. A critical component of ICH pathology is the initiation of a robust inflammatory response, often termed "cytokine storm," which amplifies the secondary brain injury following the initial hemorrhagic insult. The precise sources and consequences of this cytokine-driven inflammation are not fully elucidated, necessitating further investigation. METHODS: To address this knowledge gap, our study conducted a comprehensive cytokine profiling using Luminex® assays, assessing 23 key cytokines. We then employed single-cell RNA sequencing and spatial transcriptomics at three critical time points post-ICH: the hyperacute, acute, and subacute phases. Integrating these multimodal analyses allowed us to identify the cellular origins of cytokines and elucidate their mechanisms of action. RESULTS: Luminex® cytokine assays revealed a significant upregulation of IL-6 and IL-1ß levels at the 24-h post-ICH time point. Through the integration of scRNA-seq and spatial transcriptomics in the hemorrhagic hemisphere of rats, we observed a pronounced activation of cytokine-related signaling pathways within the choroid plexus. Initially, immune cell presence was sparse, but it surged 24 h post-ICH, particularly in the choroid plexus, indicating a substantial shift in the immune microenvironment. We traced the source of IL-1ß and IL-6 to endothelial cells, establishing a link to pyroptosis. Endothelial pyroptosis post-ICH induced the production of IL-1ß and IL-6, which activated microglial polarization characterized by elevated expression of Msr1, Lcn2, and Spp1 via the NF-κB pathway in the choroid plexus. Furthermore, we identified neuronal populations undergoing apoptosis, mediated by the Lcn2-SLC22A17 pathway in response to IL-1ß and IL-6 signaling. Notably, the inhibition of pyroptosis using VX-765 significantly mitigated neurological impairments. CONCLUSIONS: Our study provides evidence that endothelial pyroptosis, characterized by the release of IL-1ß and IL-6, triggers microglial polarization through NF-κB pathway activation, ultimately leading to microglia-mediated neuronal apoptosis in the choroid plexus post-ICH. These findings suggest that targeted therapeutic strategies aimed at mitigating endothelial cell pyroptosis and neutralizing inflammatory cytokines may offer neuroprotection for both microglia and neurons, presenting a promising avenue for ICH treatment.

Overview of ferroptosis and pyroptosis in acute liver failure.

In this editorial, we comment on the article by Zhou et al published in a recent issue. We specifically focus on the crucial roles of ferroptosis and pyroptosis in acute liver failure (ALF), a disease with high mortality rates. Ferroptosis is the result of increased intracellular reactive oxygen species due to iron accumulation, glutathione (GSH) depletion, and decreased GSH peroxidase 4 activity, while pyroptosis is a procedural cell death mediated by gasdermin D which initiates a sustained inflammatory process. In this review, we describe the characteristics of ferroptosis and pyroptosis, and discuss the involvement of the two cell death modes in the onset and development of ALF. Furthermore, we summarize several interfering methods from the perspective of ferroptosis and pyroptosis for the alleviation of ALF. These observations might provide new targets and a theoretical basis for the treatment of ALF, which are also crucial for improving the prognosis of patients with ALF.

Acute exposure to LPS induces cardiac dysfunction via the activation of the NLRP3 inflammasome.

Systemic inflammation contributes to left ventricular (LV) dysfunction, however the role of the NLRP3 inflammasome in LV dysfunction in acute inflammatory conditions is unclear. This study investigated the role of the NLRP3 inflammasome in acute (24 h) cardiac structural and functional changes in vivo and in vitro in lipopolysaccharide (LPS)-induced inflammation. LPS-treated Sprague-Dawley (SD) rats showed increased LPS metabolite abundance in their LVs as measured by atmospheric pressure matrix-assisted laser desorption ionisation (AP-MALDI) mass spectrometry imaging (MSI). Echocardiography and histology showed that in LPS-exposed rats, LV internal diameter was decreased, with evidence of macrophage infiltration and oedema. However, there were no changes in LV wall thickness or collagen volume. Additionally, LPS-exposed rats exhibited impaired LV relaxation, potentially contributing to decreased stroke volume. While global systolic function was preserved, LPS exposure in SD rats resulted in impaired myocardial deformation assessed by speckle-tracking echocardiography. Exposure to LPS resulted in upregulation of the expression of components of the NLRP3 inflammasome in rodents. In vitro LPS exposure resulted in increased gene expression of NLRP3 and downstream cytokines IL-1ß and IL-18, antioxidant SOD2, and elevated markers of pyroptosis (GSDMD) which were inhibited by treatment with a NLRP3 antagonist. However, LPS-induced increases in the gene expression of apoptosic markers (BAX/Bcl2) were not impacted by NLRP3 antagonism. These findings suggest that inflammation induced adverse cardiac structural and functional changes is, at least in part, mediated by the NLRP3 inflammasome in acute, high-grade inflammatory states. In addition, in vitro findings suggest that while the NLRP3 inflammasome mediates pyroptotic pathways, regulation of apoptosis that is independent of the inflammasome.

Protective Effects of Baicalein on Lipopolysaccharide-Induced AR42J PACs through Attenuation of Both Inflammation and Pyroptosis via Downregulation of miR-224-5p/PARP1.

Background: Baicalein has been used to treat inflammation-related diseases; nevertheless, its specific mechanism of action is unclear. Therefore, we examined the protective effects of baicalein on lipopolysaccharide-induced damage to AR42J pancreatic acinar cells (PACs) and determined its mechanism of action for protection. Methods: An in vitro cell model of acute pancreatitis (AP) was established using lipopolysaccharide (LPS) (1 mg/L)-induced PACs (AR42J), and the relative survival rate was determined using the 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) technique. Flow cytometry was applied to evaluate the apoptotic rates of AR42J PACs. The RNA and protein expression of miR-224-5p, poly ADP-ribose polymerase-1 (PARP1), nuclear transcription factor-κB65 (NF-κB65), phospho-kappa B alpha(p-IκB-α), interleukin(IL)-18R, NOD-like receptor thermal protein domain-associated protein 3 (NLRP3), gasdermin D (GSDMD), apoptosis-associated speck-like protein containing a CARD (ASC), and caspase-1 was detected based on the WB and RT-PCR assays. IL-1ß, IL-6, IL-18, and TNF-α expression levels in AR42J cells were measured via ELISA method. The cell morphology was examined using the AO/EB method. Results: The experiment confirmed a significant increase in the activity of AR42J cells treated with various doses of baicalein. Moreover, IL-1ß, IL-6, TNF-α, and IL-18 expression levels in AR42J cells were dramatically reduced (P < 0.05), while miR-224-5p level was obviously enhanced. The protein and gene expression of PARP1, NF-κB65, p-IκB-α, IL-18R, GSDMD, ASC, NLRP3, and caspase-1 was obviously decreased (P < 0.05). Apoptosis in AR42J cells was significantly reduced with significant improvement in cell morphology. Conclusion: Baicalein may significantly alleviate LPS-induced AR42J PAC damage by inhibiting the inflammatory response and pyroptosis. Its mode of action might be linked to higher miR-224-5p expression, which inhibits the PARP1/NF-κB and NLPR3/ASC/caspase-1/GSDMD pathways.

Significance of pyroptosis-related genes in the diagnosis and classification of diabetic kidney disease.

OBJECTIVE: This study aimed to identify the potential biomarkers associated with pyroptosis in diabetic kidney disease (DKD). METHODS: Three datasets from the Gene Expression Omnibus (GEO) were downloaded and merged into an integrated dataset. Differentially expressed genes (DEGs) were filtered and intersected with pyroptosis-related genes (PRGs). Pyroptosis-related DEGs (PRDEGs) were obtained and analyzed using functional enrichment analysis. Random forest, Least Absolute Shrinkage and Selection Operator, and logistic regression analyses were used to select the features of PRDEGs. These feature genes were used to build a diagnostic prediction model, identify the subtypes of the disease, and analyze their interactions with transcription factors (TFs)/miRNAs/drugs and small molecules. We conducted a comparative analysis of immune cell infiltration at different risk levels of pyroptosis. qRT-PCR was used to validate the expression of the feature genes. RESULTS: A total of 25 PRDEGs were obtained. These genes were coenriched in biological processes and pathways, such as the regulation of inflammatory responses. Five key genes (CASP1, CITED2, HTRA1, PTGS2, S100A12) were identified and verified using qRT-PCR. The diagnostic model based on key genes has a good diagnostic prediction ability. Five key genes interacted with TFs and miRNAs in 67 and 80 pairs, respectively, and interacted with 113 types of drugs or molecules. Immune infiltration of samples with different pyroptosis risk levels showed significant differences. Thus, CASP1, CITED2, HTRA1, PTGS2 and S100A12 are potential DKD biomarkers. CONCLUSION: Genes that regulate pyroptosis can be used as predictors of DKD. Early diagnosis of DKD can aid in its effective treatment.