Small Intestinal Endocrine Cell Derived Exosomal ACE2 Protects Islet ß-Cell Function by Inhibiting the Activation of NLRP3 Inflammasome and Reducing ß-Cell Pyroptosis.

Background: The "gut-islets axis" is an important endocrine signaling axis that regulates islets function by modulating the gut microbiota and endocrine metabolism within the gut. However, the specific mechanisms and roles of the intestine in islets regulation remain unclear. Recent studies investigated that exosomes derived from gut microbiota can transport signals to remotely regulate islets ß-cell function, suggesting the possibility of novel signaling pathways mediated by gut exosomes in the regulation of the "gut-islet axis.". Methods: The exosomes were isolated from the intestinal enteroendocrine cell-line STC-1cells culture supernatants treated with palmitate acid (PA) or BSA. Metabolic stress models were established by separately subjecting MIN6 cells to PA stimulation and feeding mice with a high-fat diet. Intervention with exosomes in vitro and in vivo to assess the biological effects of exosomes on islets ß cells under metabolic stress. The Mas receptor antagonist A779 and ACE2ko mice were used to evaluate the role of exosomal ACE2. Results: We found ACE2, a molecule that plays a crucial role in the regulation of islets function, is abundantly expressed in exosomes derived from STC-1 under physiological normal condition (NCEO). These exosomes cannot only be taken up by ß-cells in vitro but also selectively transported to the islets in vivo. Following intervention with NCEXO, both Min6 cells in a lipotoxic environment and mice on a high-fat diet exhibited significant improvements in islets ß-cell function and ß-cell mass. Further investigations demonstrated that these protective effects are attributed to exosomal ACE2, as ACE2 inhibits NLRP3 inflammasome activation and reduces ß-cell pyroptosis. Conclusion: ACE2-enriched exosomes from the gut can selectively target islets, subsequently inhibiting NLRP3 inflammasome activation and ß cell pyroptosis, thereby restoring islets ß cell function under metabolic stress. This study provides novel insights into therapeutic strategies for the prevention and treatment of obesity and diabetes.

LPS and ATP-induced Death of PMA-differentiated THP-1 Macrophages and its Validation.

Cell death is a fundamental process in all living organisms. The protocol establishes a lipopolysaccharide (LPS) and adenosine triphosphate (ATP)-induced phorbol-12-myristate-13-acetate (PMA)-differentiated lipid deposition in human monocyte (THP-1) macrophage model to observe cell death. LPS combined with ATP is a classic inflammatory induction method, often used to study pyroptosis, but apoptosis and necroptosis also respond to stimulation by LPS/ATP. Under normal circumstances, phosphatidylserine is only localized in the inner leaflet of the plasma membrane. However, in the early stages of pyroptosis, apoptosis, and necroptosis, the cell membrane remains intact and exposed to phosphatidylserine, and in the later stages, the cell membrane loses its integrity. Here, flow cytometry was used to analyze Annexin V and 7-Aminoactinomycin D (AAD) double staining to detect the cell death from the whole cells. The results show that substantial cells died after stimulation with LPS/ATP. Using scanning electron microscopy, we observe the possible forms of cell death in individual cells. The results indicate that cells may undergo pyroptosis, apoptosis, or necroptosis after stimulation with LPS/ATP. This protocol focuses on observing the death of macrophages after stimulation with LPS/ATP. The results showed that cell death after LPS and ATP stimulation is not limited to pyroptosis and that apoptosis and necrotic apoptosis can also occur, helping researchers better understand cell death after LPS and ATP stimulation and choose a better experimental method.

Quetiapine attenuates cadmium neurotoxicity by suppressing oxidative stress, inflammation, and pyroptosis.

BACKGROUND: Cadmium (Cd) is a heavy metal with extremely harmful toxic effects on the brain. Quetiapine (QTP) has unique neuroprotective effects with anti-inflammatory and antioxidant actions. However, its neuroprotective effect against Cd-induced neurotoxicity has not been previously studied. METHODS: QTP was administered in 10 and 20 mg/kg doses, while Cd was given in a dose of 6.5 mg/kg. RESULTS: In our study, QTP dose-dependently attenuated neuronal injury by downregulating p-tau and ß-amyloid. QTP potently attenuates histological abrasions induced by Cd. QTP counteracted oxidative injury by decreasing neuronal MDA and increased GSH levels mediated by downregulating Keap1 and upregulating Nrf2 and HO-1. QTP mitigated inflammation by decreasing MPO and NO2 and neuronal cytokines TNF-α and IL-1ß and upregulating IL-10 levels mediated by NF-κB downregulation. Additionally, QTP counteracted Cd-induced pyroptosis by downregulating caspase-1, ASC, and NLRP3 protein levels. CONCLUSION: In conclusion, QTP mitigates neurotoxicity induced by Cd through suppression of inflammation, pyroptosis, and oxidative stress by controlling the NF-κB, Keap1/Nrf2, and pyroptosis signals.

An Alkaline Nanocage Continuously Activates Inflammasomes by Disrupting Multiorganelle Homeostasis for Efficient Pyroptosis.

Pyroptosis has garnered increasing attention because of its ability to trigger robust antitumor immunity. Pyroptosis is initiated by the activation of inflammasomes, which are regulated by various organelles. The collaboration among organelles offers several protective mechanisms to prevent activation of the inflammasome, thereby limiting the induction of efficient pyroptosis. Herein, a multiorganelle homeostasis disruptor (denoted BLL) is constructed by encapsulating liposomes and bortezomib (BTZ) within a layered double hydroxide (LDH) nanocage to continuously activate inflammasomes for inducing efficient pyroptosis. In lysosomes, the negatively charged liposomes are released to recruit the NLRP3 inflammasomes through electrostatic interactions. ER stress is induced by BTZ to enhance the activation of the NLRP3 inflammasome. Meanwhile, the BLL nanocage exhibited H+-scavenging ability due to the weak alkalinity of LDH, thus disrupting the homeostasis of the lysosome and alleviating the degradation of the NLRP3 inflammasome by lysosomal-associated autophagy. Our results suggest that the BLL nanocage induces homeostatic imbalance in various organelles and efficient pyroptosis. We hope this work can provide new insights into the design of an efficient pyroptosis inducer by disrupting the homeostatic balance of multiple organelles and promote the development of novel antineoplastic platforms.

Drugs targeting CMPK2 inhibit pyroptosis to alleviate severe pneumonia caused by multiple respiratory viruses.

Severe pneumonia caused by respiratory viruses has become a major threat to humans, especially with the SARS-CoV-2 outbreak and epidemic. The aim of this study was to investigate the universal molecular mechanism of severe pneumonia induced by multiple respiratory viruses and to search for therapeutic strategies targeting this universal molecular mechanism. The common differential genes of four respiratory viruses, including respiratory syncytial virus (RSV), rhinovirus, influenza, and SARS-CoV-2, were screened by GEO database, and the hub gene was obtained by Sytohubba in Cytoscape. Then, the effect of hub genes on inflammasome and pyrodeath was investigated in the model of RSV infection in vitro and in vivo. Finally, through virtual screening, drugs targeting the hub gene were obtained, which could alleviate severe viral pneumonia in vitro and in vivo. The results showed that CMPK2 is one of the hub genes after infection by four respiratory viruses. CMPK2 activates the inflammasome by activating NLRP3, and promotes the releases of inflammatory factors interleukin (IL)-1ß and IL-18 to induce severe viral pneumonia. Z25 and Z08 can reduce the expression level of CMPK2 mRNA and protein, thereby inhibiting NLRP3 and alleviating the development of severe viral pneumonia. In conclusion, the inflammatory response mediated by CMPK2 is the common molecular mechanism of severe pneumonia induced by viral infection, and Z25 and Z08 can effectively alleviate viral infection and severe pneumonia through this mechanism.

m6A-methylated Lonp1 drives mitochondrial proteostasis stress to induce testicular pyroptosis upon environmental cadmium exposure.

Cadmium (Cd) is a widely distributed typical environmental pollutant and one of the most toxic heavy metals. It is well-known that environmental Cd causes testicular damage by inducing classic types of cell death such as cell apoptosis and necrosis. However, as a new type of cell death, the role and mechanism of pyroptosis in Cd-induced testicular injury remain unclear. In the current study, we used environmental Cd to generate a murine model with testicular injury and AIM2-dependent pyroptosis. Based on the model, we found that increased cytoplasmic mitochondrial DNA (mtDNA), activated mitochondrial proteostasis stress occurred in Cd-exposed testes. We used ethidium bromide to generate mtDNA-deficient testicular germ cells and further confirmed that increased cytoplasmic mtDNA promoted AIM2-dependent pyroptosis in Cd-exposed cells. Uracil-DNA glycosylase UNG1 overexpression indicated that environmental Cd blocked UNG-dependent repairment of damaged mtDNA to drive the process in which mtDNA releases to cytoplasm in the cells. Interestingly, we found that environmental Cd activated mitochondrial proteostasis stress by up-regulating protein expression of LONP1 in testes. Testicular specific LONP1-knockdown significantly reversed Cd-induced UNG1 protein degradation and AIM2-dependent pyroptosis in mouse testes. In addition, environmental Cd significantly enhanced the m6A modification of Lonp1 mRNA and its stability in testicular germ cells. Knockdown of IGF2BP1, a reader of m6A modification, reversed Cd-induced upregulation of LONP1 protein expression and pyroptosis activation in testicular germ cells. Collectively, environmental Cd induces m6A modification of Lonp1 mRNA to activate mitochondrial proteostasis stress, increase cytoplasmic mtDNA content, and trigger AIM2-dependent pyroptosis in mouse testes. These findings suggest that mitochondrial proteostasis stress is a potential target for the prevention of testicular injury.

Gas-Amplified Metalloimmunotherapy with Dual Activation of Pyroptosis and the STING Pathway for Remodeling the Immunosuppressive Cervical Cancer Microenvironment.

The immunosuppressive microenvironment of cervical cancer significantly hampers the effectiveness of immunotherapy. Herein, PEGylated manganese-doped calcium sulfide nanoparticles (MCSP) were developed to effectively enhance the antitumor immune response of the cervical cancer through gas-amplified metalloimmunotherapy with dual activation of pyroptosis and STING pathway. The bioactive MCSP exhibited the ability to rapidly release Ca2+, Mn2+, and H2S in response to the tumor microenvironment. H2S disrupted the calcium buffer system of cancer cells by interfering with the oxidative phosphorylation pathway, leading to calcium overload-triggered pyroptosis. On the other hand, H2S-mediated mitochondrial dysfunction further promoted the release of mitochondrial DNA (mtDNA), enhancing the activation effect of Mn2+ on the cGAS-STING signaling axis and thereby activating immunosuppressed dendritic cells. The released H2S acted as an important synergist between Mn2+ and Ca2+ by modulating dual signaling mechanisms to bridge innate and adaptive immune responses. The combination of MCSP NPs and PD-1 immunotherapy achieved synergistic antitumor effects and effectively inhibited tumor growth. This study reveals the potential collaboration between H2S gas therapy and metalloimmunotherapy and provides an idea for the design of nanoimmunomodulators for rational regulation of the immunosuppressive tumor microenvironment.

Balancing Bioresponsive Biofilm Eradication and Guided Tissue Repair via Pro-Efferocytosis and Bidirectional Pyroptosis Regulation during Implant Surgery.

There is an increasingly growing demand to balance tissue repair guidance and opportunistic infection (OI) inhibition in clinical implant surgery. Herein, we developed a nanoadjuvant for all-stage tissue repair guidance and biofilm-responsive OI eradication via in situ incorporating Cobaltiprotoporphyrin (CoPP) into Prussian blue (PB) to prepare PB-CoPP nanozymes (PCZs). Released CoPP possesses a pro-efferocytosis effect for eliminating apoptotic and progressing necrotic cells in tissue trauma, thus preventing secondary inflammation. Once OIs occur, PCZs with switchable nanocatalytic capacity can achieve bidirectional pyroptosis regulation. Once reaching the acidic biofilm microenvironment, PCZs possess peroxidase (POD)-like activity that can generate reactive oxygen species (ROS) to eradicate bacterial biofilms, especially when synergized with the photothermal effect. Furthermore, generated ROS can promote macrophage pyroptosis to secrete inflammatory cytokines and antimicrobial proteins for biofilm eradication in vivo. After eradicating the biofilm, PCZs possess catalase (CAT)-like activity in a neutral environment, which can scavenge ROS and inhibit macrophage pyroptosis, thereby improving the inflammatory microenvironment. Briefly, PCZs as nanoadjuvants feature the capability of all-stage tissue repair guidance and biofilm-responsive OI inhibition that can be routinely performed in all implant surgeries, providing a wide range of application prospects and commercial translational value.

Ferroptosis, pyroptosis and necroptosis in hepatocellular carcinoma immunotherapy: Mechanisms and immunologic landscape (Review).

Hepatocellular carcinoma (HCC), one of the leading causes of cancer­related mortality worldwide, is challenging to identify in its early stages and prone to metastasis, and the prognosis of patients with this disease is poor. Treatment options for HCC are limited, with even radical treatments being associated with a risk of recurrence or transformation in the short term. Furthermore, the multi­tyrosine kinase inhibitors approved for first­line therapy have marked drawbacks, including drug resistance and side effects. The rise and breakthrough of immune checkpoint inhibitors (ICIs) have provided a novel direction for HCC immunotherapy but these have the drawback of low response rates. Since avoiding apoptosis is a universal feature of cancer, the induction of non­apoptotic regulatory cell death (NARCD) is a novel strategy for HCC immunotherapy. At present, NARCD pathways, including ferroptosis, pyroptosis and necroptosis, are novel potential forms of immunogenic cell death, which have synergistic effects with antitumor immunity, transforming immune 'cold' tumors into immune 'hot' tumors and exerting antitumor effects. Therefore, these pathways may be targeted as a novel treatment strategy for HCC. In the present review, the roles of ferroptosis, pyroptosis and necroptosis in antitumor immunity in HCC are discussed, and the relevant targets and signaling pathways, and the current status of combined therapy with ICIs are summarized. The prospects of targeting ferroptosis, pyroptosis and necroptosis in HCC immunotherapy are also considered.

Pyroptosis inhibitors MCC950 and VX-765 mitigate myocardial injury by alleviating oxidative stress, inflammation, and apoptosis in acute myocardial hypoxia.

Acute myocardial infarction (AMI) is a prevalent cardiovascular disease with high morbidity and mortality rates worldwide. Pyroptosis is an inflammatory form of programmed cell death that has been linked to various pathological conditions. However, its exact contribution to the onset and progression of heart injury in AMI has not yet fully elucidated. Herein, we established mouse AMI model by ligating the left anterior descending artery and performed transcriptome analysis during the early phase of AMI. Mouse HL-1 and human AC-16 cardiomyocytes were subjected to hypoxia to simulate ischemic injury in vitro. Our results revealed a significant activation of the inflammatory response at 3 h post-ligation, as confirmed by RNA sequencing. We identified the occurrence of NLRP3 inflammasome-mediated pyroptosis in the cardiac tissues of human cases with AMI, as well as in mouse models of AMI and hypoxia-induced cardiomyocytes, using immunohistochemistry staining and Western blotting assays. Concurrently, pharmacological inhibition of NLRP3 inflammasome-mediated pyroptosis with MCC950 and VX-765 effectively decreased hypoxia-induced cardiomyocytes injury, while mitigating myocardial oxidative stress, apoptosis and inflammation caused by hypoxia. Moreover, the circulating levels of gasdermin D (GSDMD), the pyroptosis executor, were remarkably elevated in the plasma of mice with early AMI and in the supernatant of hypoxia-exposed cardiomyocytes in a time-dependent manner using ELISA and Western blotting. Furthermore, the change in circulating GSDMD positively correlated with Creatine Kinase-MB (CK-MB) in the plasma of early-stage AMI mouse. In summary, these findings indicated a critical role for NLRP3 inflammasome-mediated pyroptosis in the progression of AMI, the administration of MCC950 and VX-765 may be attractive candidate therapeutic approaches for cardiac injury caused by acute hypoxia or even AMI. Additionally, the circulating GSDMD exhibits potential as a newly diagnostic biomarker for AMI.

Metal-Organic Framework-Based Nanovaccine for Relieving Immunosuppressive Tumors via Hindering Efferocytosis of Macrophages and Promoting Pyroptosis and Cuproptosis of Cancer Cells.

Current cancer vaccines face challenges due to an immunosuppressive tumor microenvironment and their limited ability to produce an effective immune response. To address the above limitations, we develop a 3-(2-spiroadamantyl)-4-methoxy-4-(3-phosphoryloxy)-phenyl-1,2-dioxetane (alkaline phosphatase substrate) and XMD8-92 (extracellular signal-regulated kinase 5 inhibitor)-codelivered copper-tetrahydroxybenzoquinone (Cu-THBQ/AX) nanosized metal-organic framework to in situ-generate therapeutic vaccination. Once inside the early endosome, the alkaline phosphatase overexpressed in the tumor cells' membrane activates the in situ type I photodynamic effect of Cu-THBQ/AX for generating •O2-, and the Cu-THBQ/AX catalyzes O2 and H2O2 to •O2- and •OH via semiquinone radical catalysis and Fenton-like reactions. This surge of ROS in early endosomes triggers caspase-3-mediated proinflammatory pyroptosis via activating phospholipase C. Meanwhile, Cu-THBQ/AX can also induce the oligomerization of dihydrolipoamide S-acetyltransferase to trigger tumor cell cuproptosis. The production of •OH could also trigger the release of XMD8-92 for effectively inhibiting the efferocytosis of macrophages to convert immunosuppressive apoptosis of cancer cells into proinflammatory secondary necrosis. The simultaneous induction of pyroptosis, cuproptosis, and secondary necrosis effectively converts the tumor microenvironment from "cold" to "hot" conditions, making it an effective antigen pool. This transformation successfully activates the antitumor immune response, inhibiting tumor growth and metastasis.

[Mechanisms of NLRP3 inflammasome-mediated pyroptosis in chronic heart failure and research progress in traditional Chinese medicine].

Chronic heart failure(CHF) is a severe cardiovascular disease characterized by a complex pathogenesis involving myocardial structural and functional abnormalities and the activation of inflammatory responses. The NOD-like receptor thermal protein domain-associated protein 3(NLRP3) inflammasome, acting as a sensor for inflammatory cells, plays a pivotal role in the development of CHF. Research indicates that the activation of the NLRP3 inflammasome can induce inflammatory responses, leading to cardiac inflammation and impairing myocardial function, and it is correlated with the severity of CHF. Traditional Chinese medicine(TCM) has garnered increasing attention as a traditional therapeutic approach in recent years. Various TCM drugs and treatment methods have exhibited potential efficacy in suppressing inflammatory responses, alleviating myocardial cell pyroptosis, improving myocardial structure and function, and inhibiting myocardial fibrosis. Several TCM drugs and their extracts have been utilized in CHF treatment, with mechanisms potentially involving the inhibition of NLRP3 inflammasomes and the mitigation of inflammatory responses. The article provided an overview of the composition, structural characteristics, initiation, and activation modes of the NLRP3 inflammasome, its mechanisms in CHF, and the research progress of TCM in CHF treatment. It aims to offer references and foundations for a deeper understanding of CHF pathogenesis and subsequent development of new therapeutic strategies.

[Effect and mechanism of free total rhubarb anthraquinones on pyroptosis of J774A.1 macrophages].

In this study, J774A.1 macrophages stimulated by lipopolysaccharide(LPS) and adenosine triphosphate(ATP) were used to establish an in vitro model of pyroptosis, and the intervention mechanism of free total rhubarb anthraquinones(FTRAs) on pyroptosis was investigated. J774A.1 macrophages were cultured in vitro, and the experiment was assigned to the control group and groups with different concentrations of LPS(0.25, 0.5, and 1 µg·mL~(-1)) and ATP(1.25, 2.5, and 5 mmol·L~(-1)). An in vitro model of macrophage pyroptosis was established by detecting cell viability through CCK-8, propidium iodide(PI) apoptotic cell staining, lactate dehydrogenase(LDH), interleukin(IL)-18, and tumor necrosis factor(TNF)-α release. Then, J774A.1 macrophages were randomly divided into six groups: blank control group, LPS+ATP group, high-dose FTRA group, and low, medium, and high-dose FTRA pre-protection group. The phenotypic characteristics and key indicators of pyroptosis were detected as the basis for evaluating the effect of FTRAs on pyroptosis induced by LPS and ATP. Western blot and RT-PCR were used to detect the expression levels of protein and mRNA related to the pyroptosis pathway in caspase-1/11 and elucidate the molecular mechanism of the anti-pyroptosis effect. The results showed that the stimulation condition of 0.50 µg·mL~(-1) LPS+5.00 mmol·L~(-1) ATP was the most effective in the in vitro model of macrophage pyroptosis. FTRAs pre-protected cells for 24 h and then can increase cell viability under pyroptosis conditions, alleviate cell damage, lower the positive rate of PI staining, and reduce the release of LDH, IL-18, and TNF-α. FTRAs were able to significantly inhibit the activation of GSDMD proteins and significantly down-regulate the protein expression of the pyroptosis pathway signature molecules, TLR4, NLRP3, cleaved-caspase-1, and cleaved-caspase-11, but they had no significant effect on ASC proteins. FTRAs were also able to significantly inhibit the mRNA expression of caspase-1, caspase-11, and GSDMD. These results indicate that FTRAs have an inhibitory effect on the pyroptosis model induced by LPS and ATP and play an anti-pyroptosis effect by regulating classical and non-classical pyroptosis signaling pathways and reducing the production of inflammatory cytokines.

Immunogenic oncolysis by tigilanol tiglate.

Tigilanol tiglate is an oncolytic small molecule that is undergoing clinical trials. A recent study revealed the capacity of this pyroptosis inducer to elicit hallmarks of immunogenic cell death. In addition, intratumoral injection of tigilanol tiglate can sensitize subcutaneous cancers to subsequent immune checkpoint inhibitors targeting CTLA-4 alone or in combination with PD-1.

Modulating synovial macrophage pyroptosis and mitophagy interactions to mitigate osteoarthritis progression using functionalized nanoparticles.

Synovial macrophages play an important role in the progression of osteoarthritis (OA). In this study, we noted that synovial macrophages can activate pyroptosis in a gasdermin d-dependent manner and produce reactive oxygen species (ROS), aberrantly activating the mammalian target of rapamycin complex 1 (mTORC1) pathway and matrix metalloproteinase-9 (MMP9) expression in synovial tissue samples collected from both patients with OA and collagen-induced osteoarthritis (CIOA) mouse model. To overcome this, we constructed rapamycin- (RAPA, a mTORC1 inhibitor) loaded mesoporous Prussian blue nanoparticles (MPB NPs, for catalyzing ROS) and modified the NPs with MMP9-targeted peptides (favor macrophage targeting) to develop RAPA@MPB-MMP9 NPs. The inherent enzyme-like activity and RAPA released from RAPA@MPB-MMP9 NPs synergistically impeded the pyroptosis of macrophages and the activation of the mTORC1 pathway. In particular, the NPs decreased pyroptosis-mediated ROS generation, thereby inhibiting cGAS-STING signaling pathway activation caused by the release of mitochondrial DNA. Moreover, the NPs promoted macrophage mitophagy to restore mitochondrial stability, alleviate pyroptosis-related inflammatory responses, and decrease senescent synoviocytes. After the as-prepared NPs were intra-articularly injected into the CIOA mouse model, they efficiently attenuated synovial macrophage pyroptosis and cartilage degradation. In conclusion, our study findings provide a novel therapeutic strategy for OA that modulates the pyroptosis and mitophagy of synovial macrophage by utilizing functionalized NPs. STATEMENT OF SIGNIFICANCE: Osteoarthritis (OA) presents a significant global challenge owing to its complex pathogenesis and finite treatment options. Synovial macrophages have emerged as key players in the progression of OA, managing inflammation and tissue destruction. In this study, we discovered a novel therapeutic strategy in which the pyroptosis and mitophagy of synovial macrophages are targeted to mitigate OA pathology. For this, we designed and prepared rapamycin-loaded mesoporous Prussian blue nanoparticles (RAPA@MPB-MMP9 NPs) to specifically target synovial macrophages and modulate their inflammatory responses. These NPs could efficiently suppress macrophage pyroptosis, diminish reactive oxygen species production, and promote mitophagy, thereby alleviating inflammation and protecting cartilage integrity. Our study findings not only clarify the intricate mechanisms underlying OA pathogenesis but also present a promising therapeutic approach for effectively managing OA by targeting dysregulation in synovial macrophages.

Apigenin alleviates doxorubicin-induced myocardial pyroptosis by inhibiting glycogen synthase kinase-3ß in vitro and in vivo.

Apigenin, a natural flavonoid compound found in chamomile (Matricaia chamomilla L.) from the Asteraceae family, has been shown in our previous study to possess antimyocardial hypertrophy and anti-cardiac fibrosis effects. However, its effects and mechanisms on the pyroptosis of cardiomyocytes induced by doxorubicin (DOX) are poorly understood. The objective of this study was to investigate the role of GSK-3ß and the effects of apigenin in DOX-induced cardiotoxicity. H9c2 cells stimulated with DOX were treated with SB216763 and apigenin. Additionally, a mouse model of DOX-induced cardiotoxicity was prepared and further treated with apigenin and SB216763 for 30 days. The findings revealed that treatment with SB216763 or apigenin resulted in a significant reduction in the levels of pyroptosis-related factors. Furthermore, the phosphorylation of GSK-3ß was enhanced while the phosphorylation of nuclear factor-kB (NF-κB) p65 was reduced following treatment with either SB216763 or apigenin. Conversely, the effects of apigenin treatment were nullified in siRNA-GSK-3ß-transfected cells. Results from computer simulation and molecular docking analysis supported that apigenin could directly target the regulation of GSK-3ß. Therefore, our study confirmed that the inhibition of GSK-3ß and treatment with apigenin effectively suppressed the pyroptosis of cardiomyocytes in both DOX-stimulated H9c2 cells and mice. These benefits may be attributed in part to the decrease in GSK-3ß expression and subsequent reduction in NF-κB p65 activation. Overall, our findings revealed that the pharmacological targeting of GSK-3ß may offer a promising therapeutic approach for alleviating DOX-induced cardiotoxicity.

Magnoflorine Ameliorates Chronic Kidney Disease in High-Fat and High-Fructose-Fed Mice by Promoting Parkin/PINK1-Dependent Mitophagy to Inhibit NLRP3/Caspase-1-Mediated Pyroptosis.

Excessive intake of fat and fructose in Western diets has been confirmed to induce renal lipotoxicity, thereby driving the progression of chronic kidney disease (CKD). This study was conducted to evaluate the efficacy of magnoflorine in a CKD mouse model subjected to high-fat and high-fructose diets. Our results demonstrated that magnoflorine treatment ameliorated abnormal renal function indices (serum creatinine, urea nitrogen, uric acid, and urine protein) in high-fat- and high-fructose-fed mice. Histologically, renal tubular cell steatosis, lipid deposition, tubular dilatation, and glomerular fibrosis were significantly reduced by the magnoflorine treatment in these mice. Mechanistically, magnoflorine promotes Parkin/PINK1-mediated mitophagy, thereby inhibiting NLRP3/Caspase-1-mediated pyroptosis. Consistent findings were observed in the palmitic acid-incubated HK-2 cell model. Notably, both silencing of Parkin and the use of a mitophagy inhibitor reversed the inhibitory effect of magnoflorine on NLRP3 inflammasome activation in vitro. Therefore, the present study provides compelling evidence that magnoflorine improves renal injury in high-fat- and high-fructose-fed mice by promoting Parkin/PINK1-dependent mitophagy to inhibit NLRP3 inflammasome activation and pyroptosis. Our findings suggest that dietary supplementation with magnoflorine and magnoflorine-rich foods (such as magnolia) might be an effective strategy for the prevention of CKD.

Induction of Hepatoma Cell Pyroptosis by Endogenous Lipid Geranylgeranoic Acid-A Comparison with Palmitic Acid and Retinoic Acid.

Research on retinoid-based cancer prevention, spurred by the effects of vitamin A deficiency on gastric cancer and subsequent clinical studies on digestive tract cancer, unveils novel avenues for chemoprevention. Acyclic retinoids like 4,5-didehydrogeranylgeranoic acid (4,5-didehydroGGA) have emerged as potent agents against hepatocellular carcinoma (HCC), distinct from natural retinoids such as all-trans retinoic acid (ATRA). Mechanistic studies reveal GGA's unique induction of pyroptosis, a rapid cell death pathway, in HCC cells. GGA triggers mitochondrial superoxide hyperproduction and ER stress responses through Toll-like receptor 4 (TLR4) signaling and modulates autophagy, ultimately activating pyroptotic cell death in HCC cells. Unlike ATRA-induced apoptosis, GGA and palmitic acid (PA) induce pyroptosis, underscoring their distinct mechanisms. While all three fatty acids evoke mitochondrial dysfunction and ER stress responses, GGA and PA inhibit autophagy, leading to incomplete autophagic responses and pyroptosis, whereas ATRA promotes autophagic flux. In vivo experiments demonstrate GGA's potential as an anti-oncometabolite, inducing cell death selectively in tumor cells and thus suppressing liver cancer development. This review provides a comprehensive overview of the molecular mechanisms underlying GGA's anti-HCC effects and underscores its promising role in cancer prevention, highlighting its importance in HCC prevention.

Bushen Huoxue formula protects against renal fibrosis and pyroptosis in chronic kidney disease by inhibiting ROS/NLRP3-mediated inflammasome activation.

BACKGROUND: Renal fibrosis contributes to chronic renal failure and a decline in the quality of life. Bushen Huoxue (BSHX) formula is a Traditional Chinese Medicine used to treat chronic renal failure. However, its mechanisms of action remain unclear. METHODS AND RESULTS: In this study, a rat model of renal fibrosis was constructed by 5/6 nephrectomy in vivo, and histopathological changes were analyzed using hematoxylin-eosin and Masson's trichrome staining. Angiotensin II (Ang II) was used to establish an in vitro renal fibrosis cell model in vitro. Pyroptosis was measured using flow cytometry. Related markers of fibrosis and NOD-like receptor protein 3 (NLRP3) inflammasome activation were measured using western blotting and enzyme-linked immunosorbent assay. Treatment with BSHX (0.25, 0.5, and 1 g/kg) significantly inhibited renal fibrosis and damage in 5/6 nephrectomized rats and simultaneously reduced oxidative stress and NLRP3 inflammasome activation. Similarly, BSHX treatment reduced the levels of hydroxyproline, transforming growth factor-ß, matrix metalloproteinase 2, and matrix metalloproteinase 9 and inactivated the Smad2/3 signaling pathway in Ang II-treated HK-2 cells. Our data also showed that treatment with BSHX reduced NLRP3 inflammasome activation and pyroptosis in Ang II-treated HK-2 cells. Moreover, fibrosis and pyroptosis in HK-2 cells induced by NLRP3 overexpression were reduced by treatment with BSHX. CONCLUSIONS: BSHX significantly reduced renal fibrosis and pyroptosis, and its mechanism was mainly associated with the inhibition of reactive oxygen species (ROS)/NLRP3-mediated inflammasome activation.

Peroxiredoxin II exerts neuroprotective effects by inhibiting endoplasmic reticulum stress and oxidative stress-induced neuronal pyroptosis.

BACKGROUND: Intracerebral hemorrhage (ICH) is a critical neurological condition with few treatment options, where secondary immune responses and specific cell death forms, like pyroptosis, worsen brain damage. Pyroptosis involves gasdermin-mediated membrane pores, increasing inflammation and neural harm, with the NLRP3/Caspase-1/GSDMD pathway being central to this process. Peroxiredoxin II (Prx II), recognized for its mitochondrial protection and reactive oxygen species (ROS) scavenging abilities, appears as a promising neuronal pyroptosis modulator. However, its exact role and action mechanisms need clearer definition. This research aims to explore Prx II impact on neuronal pyroptosis and elucidate its mechanisms, especially regarding endoplasmic reticulum (ER) stress and oxidative stress-induced neuronal damage modulation. METHODS AND RESULTS: Utilizing MTT assays, Microscopy, Hoechst/PI staining, Western blotting, and immunofluorescence, we found Prx II effectively reduces LPS/ATP-induced pyroptosis and neuroinflammation in HT22 hippocampal neuronal cells. Our results indicate Prx II's neuroprotective actions are mediated through PI3K/AKT activation and ER stress pathway inhibition, diminishing mitochondrial dysfunction and decreasing neuronal pyroptosis through the ROS/MAPK/NF-κB pathway. These findings highlight Prx II potential therapeutic value in improving intracerebral hemorrhage outcomes by lessening secondary brain injury via critical signaling pathway modulation involved in neuronal pyroptosis. CONCLUSIONS: Our study not only underlines Prx II importance in neuroprotection but also opens new therapeutic intervention avenues in intracerebral hemorrhage, stressing the complex interplay between redox regulation, ER stress, and mitochondrial dynamics in neuroinflammation and cell death management.