Nicotine promotes atherosclerosis via ROS-NLRP3-mediated endothelial cell pyroptosis

The role of discoid domain receptor 1 on renal tubular epithelial pyroptosis in diabetic nephropathy

Pyroptosis, a form of cell death associated with inflammation, is known to be involved in diabetic nephropathy (DN), and discoid domain receptor 1 (DDR1), an inflammatory regulatory protein, is reported to be associated with diabetes. However, the mechanism underlying DDR1 regulation and pyroptosis in DN remains unknown. We aimed to investigate the effect of DDR1 on renal tubular epithelial cell pyroptosis and the mechanism underlying DN. In this study, we used high glucose (HG)-treated HK-2 cells and rats with a single intraperitoneal injection of streptozotocin as DN models. Subsequently, the expression of pyroptosis-related proteins (cleaved caspase-1, GSDMD-N, Interleukin-1β [IL-1β], and interleukin-18 [IL-18]), DDR1, phosphorylated NF-κB (p-NF-κB), and NLR family pyrin domain-containing 3 (NLRP3) inflammasomes were determined through Western blotting. IL-1β and IL-18 levels were determined using ELISA. The rate of pyroptosis was assessed by propidium iodide (PI) staining. The results revealed upregulated expression of pyroptosis-related proteins and increased concentration of IL-1β and IL-18, accompanied by DDR1, p-NF-κB, and NLRP3 upregulation in DN rat kidney tissues and HG-treated HK-2 cells. Moreover, DDR1 knockdown in the background of HG treatment resulted in inhibited expression of pyroptosis-related proteins and attenuation of IL-1β and IL-18 production and PI-positive cell frequency via the NF-κB/NLRP3 pathway in HK-2 cells. However, NLRP3 overexpression reversed the effect of DDR1 knockdown on pyroptosis. In conclusion, we demonstrated that DDR1 may be associated with pyroptosis, and DDR1 knockdown inhibited HG-induced renal tubular epithelial cell pyroptosis. The NF-κB/NLRP3 pathway is probably involved in the underlying mechanism of these findings.

Autophagy triggered by the ROS/ERK signaling pathway protects mouse embryonic palatal cells from apoptosis induced by nicotine

Maternal cigarette smoking during pregnancy is a known high-risk factor for having a child with a cleft lip and/or palate (CLP), a common congenital malformation. Nicotine is the major teratogen component of cigarettes and e-cigarettes, and nicotine plays an important role in the development of CLP. However, the mechanism underlying nicotine's effect on CLP remains unclear. Here, we aimed to determine the role and molecular mechanisms of nicotine-induced autophagy, an important process involved in regulating the cellular stress response in mouse embryonic palatal cells (MEPCs). First, we found that nicotine promoted MEPCs proliferation and inhibited their apoptosis from 0 to 12 h. After 12 h, the proliferation was inhibited, and apoptosis was promoted. The migration of MEPCs was also inhibited by nicotine. Simultaneously, long-term nicotine stimulation inhibited the osteogenic differentiation of MEPCs. We then found that nicotine significantly increased autophagy flux in MEPCs at 12 h by increasing the expression of microtubule-associated protein light chain 3 (LC3) and reducing P62 expression levels. After nicotine exposure, intracellular reactive oxygen species (ROS) and extracellular signal-regulated kinase-1/2 (ERK1/2) expression significantly increased, and the expression of ERK1/2 was reversed by the ROS scavenging agent N-acetylcysteine (NAC). Moreover, the autophagy induced by nicotine was reversed by SCH772984, a specific inhibitor of ERK1/2, and the autophagy inhibitor chloroquine (CQ). These results suggest that in the early stage of nicotine exposure, MEPCs may trigger autophagy through the ROS/ERK1/2 signaling pathway to avoid cell damage caused by nicotine.

PCSK9 inhibitor inclisiran for treating atherosclerosis via regulation of endothelial cell pyroptosis

Background

Proprotein convertase subtilisin/kexin type 9 (PCSK9) belongs to an intracellular invertase or decarboxylase and is an independent risk factor for atherosclerosis (AS). This study aimed to investigate the therapeutic potential of the PCSK9 inhibitor, inclisiran, and its underlying mechanism in AS.

Methods

ApoE^-/- mice were fed with a high-fat diet (HFD) and intraperitoneally injected with 1, 5, or 10 mg/kg inclisiran. Low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) levels were determined using commercially available kits. Oil Red O staining was applied to detect the aortic plaque area and oil formation. Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low-density lipoprotein (ox-LDL) to induce cell injuries. Cell death was determined using a Hoechst 33342/propidium iodide (PI) dual-staining assay. Cytotoxicity was measured by lactate dehydrogenase (LDH) activity analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analyses were performed to examine the pyroptosis-related factors.

Results

Inclisiran inhibited the levels of LDL-C, TC, and TG, but increased the HDL-C level in the AS animal model. It also significantly inhibited plaque and oil droplet formation in a dose-dependent manner. Moreover, inclisiran markedly inhibited pyroptosis, as evidenced by the decreased levels of cleaved-caspase-1, NOD-like receptor family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase-1 recruitment domain (ASC), gasdermin-D (GSDMD)-N, interleukin (IL)-1β, and IL-18. Furthermore, inclisiran substantially inhibited cell death and cytotoxicity induced by ox-LDL in HUVECs.

Conclusions

Inclisiran exerted an anti-atherosclerotic effect by inhibiting pyroptosis. This study provides a theoretical basis for the therapeutic potential of inclisiran in AS.

SRPK1 promotes sepsis-induced acute lung injury via regulating PI3K/AKT/FOXO3 signaling

OBJECTIVE

Sepsis is the most common cause of death in intensive care unit. Moreover, sepsis is the leading cause of acute lung injury (ALI). Serine-arginine protein kinase 1 (SRPK1) was demonstrated to promote the development of ALI. However, the potentials of SRPK1 in sepsis-induced ALI are still unknown. This study aimed to investigate the potentials of SRPK1 in sepsis-induced ALI and the underlying mechanisms.

METHODS

Cecal ligation and puncture (CLP) was performed to establish sepsis-induced ALI model in vivo. Primary human pulmonary microvascular endothelial cells (HPMECs) were exposed to lipopolysaccharide (LPS) to construct sepsis-induced ALI model in vitro. Gene expression was detected using western blot and qRT-PCR. The interaction between forkhead box O3 (FOXO3) and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) was detected using luciferase and Chromatin immunoprecipitation (ChIP) assay. Cellular functions were CCK-8, colony formation, PI staining, and flow cytometry assay.

RESULTS

SRPK1 was downregulated in patients with sepsis-induced ALI. Overexpression of SRPK1 suppressed the pyroptosis of HPMECs as well as promoted cell proliferation. Additionally, SRPK1 overexpression alleviated sepsis-induced ALI in vivo. SRPK1 activated phosphatidylinositol3-kinase (PI3K) signaling pathways. Blocking the activation of PI3K degraded the cellular functions of HPMECs. Moreover, FOXO3 transcriptionally inactivated NLRP3 and suppressed its mRNA and protein expression.

CONCLUSION

Taken together, SRPK1 suppressed sepsis-induced ALI via regulating PI3K/AKT/FOXO3/NLRP3 signaling. SRPK1 may be the potential biomarker for sepsis-induced ALI.

Immunological Insights into Cigarette Smoking-Induced Cardiovascular Disease Risk

Smoking is one of the most prominent addictions of the modern world, and one of the leading preventable causes of death worldwide. Although the number of tobacco smokers is believed to be at a historic low, electronic cigarette use has been on a dramatic rise over the past decades. Used as a replacement for cigarette smoking, electronic cigarettes were thought to reduce the negative effects of burning tobacco. Nonetheless, the delivery of nicotine by electronic cigarettes, the most prominent component of cigarette smoke (CS) is still delivering the same negative outcomes, albeit to a lesser extent than CS. Smoking has been shown to affect both the structural and functional aspects of major organs, including the lungs and vasculature. Although the deleterious effects of smoking on these organs individually is well-known, it is likely that the adverse effects of smoking on these organs will have long-lasting effects on the cardiovascular system. In addition, smoking has been shown to play an independent role in the homeostasis of the immune system, leading to major sequela. Both the adaptive and the innate immune system have been explored regarding CS and have been demonstrated to be altered in a way that promotes inflammatory signals, leading to an increase in autoimmune diseases, inflammatory diseases, and cancer. Although the mechanism of action of CS has not been fully understood, disease pathways have been explored in both branches of the immune system. The pathophysiologically altered immune system during smoking and its correlation with cardiovascular diseases is not fully understood. Here we highlight some of the important pathological mechanisms that involve cigarette smoking and its many components on cardiovascular disease and the immune systems in order to have a better understanding of the mechanisms at play.

FGF5 alleviated acute lung injury via AKT signal pathway in endothelial cells

Acute lung injury (ALI), with high morbidity and mortality, is mainly resulted by infectious or non-infectious inflammatory stimulators, and it will further evolve into acute respiratory distress syndrome if not controlled. Fibroblast growth factors (FGFs) consist of more than 23 kinds of members, which are involved in various pathophysiological processes of body. However, the effect of FGF5, one member of FGFs, is still not certain in lipopolysaccharide (LPS)-induced ALI. In this study, we explored the possible impacts of FGF5 in LPS-induced ALI and primarily focused on endothelial cell, which was one of the most vulnerable cells in septic ALI. In the mouse group of FGF5 overexpression, LPS-induced lung injuries were mitigated, as well as the pyroptosis levels of pulmonary vascular endothelial cells. Additionally, in vitro human umbilical vein endothelial cells (HUVECs), our results showed that the level of cell pyroptosis was ameliorated with FGF5 overexpression, and AKT signal was activated with the overexpression of FGF5, whereas after administration of MK2206, an inhibitor of AKT signal, the protection of FGF5 was inhibited. Therefore, these results suggested that FGF5 exerted protective effects in endothelial cells exposed to LPS, and this protection of FGF5 could be attributed to activated AKT signal.

Gut bacteria alleviate smoking-related NASH by degrading gut nicotine

Tobacco smoking is positively correlated with non-alcoholic fatty liver disease (NAFLD)1-5, but the underlying mechanism for this association is unclear. Here we report that nicotine accumulates in the intestine during tobacco smoking and activates intestinal AMPKα. We identify the gut bacterium Bacteroides xylanisolvens as an effective nicotine degrader. Colonization of B. xylanisolvens reduces intestinal nicotine concentrations in nicotine-exposed mice, and it improves nicotine-exacerbated NAFLD progression. Mechanistically, AMPKα promotes the phosphorylation of sphingomyelin phosphodiesterase 3 (SMPD3), stabilizing the latter and therefore increasing intestinal ceramide formation, which contributes to NAFLD progression to non-alcoholic steatohepatitis (NASH). Our results establish a role for intestinal nicotine accumulation in NAFLD progression and reveal an endogenous bacterium in the human intestine with the ability to metabolize nicotine. These findings suggest a possible route to reduce tobacco smoking-exacerbated NAFLD progression.

A Mini Review on Molecules Inducing Caspase-Independent Cell Death: A New Route to Cancer Therapy

Most anticancer treatments trigger tumor cell death through apoptosis, where initiation of proteolytic action of caspase protein is a basic need. But under certain circumstances, apoptosis is prevented by the apoptosis inhibitor proteins, survivin and Hsp70. Several drugs focusing on classical programmed death of the cell have been reported to have low anti-tumorogenic potency due to mutations in proteins involved in the caspase-dependent programmed cell death with intrinsic and extrinsic pathways. This review concentrates on the role of anti-cancer drug molecules targeting alternative pathways of cancer cell death for treatment, by providing a molecular basis for the new strategies of novel anti-cancer treatment. Under these conditions, active agents targeting alternative cell death pathways can be considered as potent chemotherapeutic drugs. Many natural compounds and other small molecules, such as inorganic and synthetic compounds, including several repurposing drugs, are reported to cause caspase-independent cell death in the system. However, few molecules indicated both caspase-dependent as well caspase-free cell death in specific cancer lines. Cancer cells have alternative methods of caspase-independent programmed cell death which are equally promising for being targeted by small molecules. These small molecules may be useful leads for rational therapeutic drug design, and can be of potential interest for future cancer-preventive strategies.

Constructing and Validating a Pyroptosis-Related Genes Prognostic Signature for Stomach Adenocarcinoma and Immune Infiltration: Potential Biomarkers for Predicting the Overall Survival

Background

Stomach adenocarcinoma (STAD) is a kind of cancer that begins in the stomach cells and has a poor overall survival rate. Following resection surgery, chemotherapy has been suggested as a curative method for stomach cancer. However, it is ineffective. Pyroptosis, a kind of inflammatory programmed cell death, has been shown to play a significant role in the development and progression of STAD. However, whether pyroptosis-related genes (PRGs) can be utilized to predict the diagnosis and prognosis of gastric cancer remains unknown.

Method

The research measured at predictive PRGs in STAD samples from TCGA and GEO. Lasso regression was used to build the prediction model. Coexpression analysis revealed that gene expression was linked to pyroptosis. PRGs were found to be overexpressed in high-risk individuals, implying that they could be used in a model to predict STAD prognosis.

Result

Immunological and tumor-related pathways were discovered using GSEA. In STAD patients, the genes GPX3, PDGFRL, RGS2, and SERPINE1 may be connected to the cancer process. The levels of expression also differed between the two risk groups.

Conclusion

The purpose of this study is to identify and verify STAD-associated PRGs that can effectively guide prognosis and the immunological milieu in STAD patients as well as offer evidence for the development of pyroptosis-related molecularly targeted therapeutics. Therefore, PRGs and the link between immunological and PRGs in STAD may be therapeutic targets.

Diphenyleneiodonium Treatment Inhibits the Development of Severe Herpes Stromal Keratitis Lesions

Reactive oxygen species (ROS) play an important role in tissue inflammation. In this study, we measured the intracellular level of ROS in herpes stromal keratitis (HSK) corneas and determined the outcome of manipulating ROS level on HSK severity. Our results showed the predominance of ROS generation in neutrophils but not CD4 T cells in HSK corneas. NADPH oxidase 2 (NOX2) enzyme is known to generate ROS in myeloid cells. Our results showed baseline expression of different NOX2 subunits in uninfected corneas. After corneal herpes simplex virus-1 (HSV-1) infection, an enhanced expression of NOX2 subunits was detected in infected corneas. Furthermore, flow cytometry results showed a higher level of gp91 (Nox2 subunit) protein in neutrophils from HSK corneas, suggesting the involvement of NOX2 in generating ROS. However, no significant decrease in ROS level was noticed in neutrophils from HSV-1-infected gp91-/- mice than in C57BL/6J (B6) mice, suggesting NOX2 is not the major contributor in generating ROS in neutrophils. Next, we used diphenyleneiodonium (DPI), a flavoenzyme inhibitor, to pharmacologically manipulate the ROS levels in HSV-1-infected mice. Surprisingly, the neutrophils from peripheral blood and corneas of the DPI-treated group exhibited an increased level of ROS than the vehicle-treated group of infected B6 mice. Excessive ROS is known to cause cell death. Accordingly, DPI treatment resulted in a significant decrease in neutrophil frequency in peripheral blood and corneas of infected mice and was associated with reduced corneal pathology. Together, our results suggest that regulating ROS levels in neutrophils can ameliorate HSK severity. IMPORTANCE Neutrophils are one of the primary immune cell types involved in causing tissue damage after corneal HSV-1 infection. This study demonstrates that intracellular ROS production in the neutrophils in HSK lesions is not NOX2 dependent. Furthermore, manipulating ROS levels in neutrophils ameliorates the severity of HSK lesions. Our findings suggest that excessive intracellular ROS in neutrophils disrupt redox homeostasis and affect their survival, resulting in a decrease in HSK lesion severity.

Integrated pyroptosis measurement and metabolomics to elucidate the effect and mechanism of tangzhiqing on atherosclerosis

Tangzhiqing formula (TZQ) is a traditional Chinese medicine prescribed to treat glucose and lipid metabolism disorders. A significant effect of TZQ on diabetes and hyperlipidemia has been demonstrated, but its effect on atherosclerosis (AS) remains unknown. This study combines pyroptosis with metabolomics to elucidate the effect and mechanism of TZQ on AS. A model of AS was developed using ApoE^−/− mice fed a high-fat diet for 8 weeks. After 6 weeks of atorvastatin (Ator) or TZQ treatment, aortic lumen diameter, aortic lesion size, serum lipid profile, cytokines, and Nod-like receptor protein 3 (NLRP3) inflammasome-mediated pyroptosis were analyzed. Serum metabolomics profiles were obtained to examine the effect of TZQ on AS and the correlation between pyroptosis and metabolites was further analyzed. As a result, TZQ significantly reduced the diameter of the common carotid artery during diastole and the blood flow velocity in the aorta during systole; reduced blood lipid levels, arterial vascular plaques, and the release of inflammatory cytokines; and inhibited the NLRP3 inflammasome-mediated pyroptosis. According to metabolomics profiling, TZQ is engaged in the treatment of AS via altering arachidonic acid metabolism, glycerophospholipid metabolism, steroid hormone production, and unsaturated fatty acid biosynthesis. The cytochrome P450 enzyme family and cyclooxygenase 2 (COX-2) are two major metabolic enzymes associated with pyroptosis.

Electronic Cigarette and Atherosclerosis: A Comprehensive Literature Review of Latest Evidences

Coronary artery diseases (CAD), also known as coronary heart disease (CHD), are the world’s leading cause of death. The basis of coronary artery disease is the narrowing of the heart coronary artery lumen due to atherosclerosis. The use of electronic cigarettes has increased significantly over the years. However, harmful effects of electronic cigarettes are still not firm. The aim of this article is to review the impact of electronic cigarette and its role in the pathogenesis of atherosclerosis from recent studies. The results showed that several chemical compounds, such as nicotine, propylene glycol, particulate matters, heavy metals, and flavorings, in electronic cigarette induce atherosclerosis with each molecular mechanism that lead to atherosclerosis progression by formation of ROS, endothelial dysfunction, and inflammation. Further research is still needed to determine the exact mechanism and provide more clinical evidence.

Role of Reactive Oxygen Species in Aging and Age-Related Diseases: A Review

Research on the role of reactive oxygen species (ROS) in the aging process has advanced significantly over the last two decades. In light of recent findings, ROS takes part in the aging process of cells along with contributing to various physiological signaling pathways. Antioxidants being cells' natural defense mechanism against ROS-mediated alteration, play an imperative role to maintain intracellular ROS homeostasis. Although the complete understanding of the ROS regulated aging process is yet to be fully comprehended, current insights into various sources of cellular ROS and their correlation with the aging process and age-related diseases are portrayed in this review. In addition, results on the effect of antioxidants on ROS homeostasis and the aging process as well as their advances in clinical trials are also discussed in detail. The future perspective in ROS-antioxidant dynamics on antiaging research is also marshaled to provide future directions for ROS-mediated antiaging research fields.

Derivation and validation of a prediction score for postoperative delirium in geriatric patients undergoing hip fracture surgery or hip arthroplasty

Introduction

Postoperative delirium is a common complication of patients undergoing hip fracture surgery or arthroplasty and is related to decreased survival time and physical function. In this study, we aim to build and validate a prediction score of postoperative delirium in geriatric patients undergoing hip fracture surgery or hip arthroplasty.

Methods

A retrospective cohort of geriatric patients undergoing hip fracture surgery or hip arthroplasty was established. Variables of included patients were collected as candidate predictors of postoperative delirium. The least absolute shrinkage and selection operator (LASSO) regression and logistic regression were used to derive a predictive score for postoperative delirium. The accuracy of the score was evaluated by the area under the curve (AUC) of the receiver operating curve (ROC). We used bootstrapping resamples for model calibration. The prediction score was validated in an extra cohort.

Results

There were 1,312 patients in the derivation cohort, and the incidence of postoperative delirium was 14.33%. Of 40 variables, 9 were identified as predictors, including preoperative delirium, cerebrovascular accident (CVA) with the modified Rankin scale, diabetes with a random glucose level, Charlson comorbidity index (CCI), age, application of benzodiazepines in surgery, surgical delay ≥2 days, creatine ≥90 μmol/L, and active smoker. The prediction score achieved a mean AUC of 0.848 in the derivation cohort. In the validation cohort, the mean AUC was 0.833. The prediction model was well-calibrated in the two cohorts.

Conclusion

Based on retrospective data, a prediction score for postoperative delirium in geriatric patients undergoing hip fracture surgery or hip arthroplasty was derived and validated. The performance of the scoring system outperformed the models from previous studies. Although the generalization ability of the score needs to be tested in similar populations, the scoring system will enable delirium risk stratification for hip fracture patients and facilitate the development of strategies for delirium prevention.

Role of NLRP3 inflammasome in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune rheumatic disease with high mortality, which is featured by inflammation, vascular damage, and aggressive fibrosis. To date, the pathogenesis of SSc remains unclear and effective treatments are still under research. Active NLRP3 recruits downstream proteins such as ASC and caspase-1 and assembles into inflammasome, resulting in excretion of inflammatory cytokines including IL-1β and IL-18, as well as in pyroptosis mediated by gasdermin D. Various studies demonstrated that NLRP3 inflammasome might be involved in the mechanism of tenosynovitis, arthritis, fibrosis, and vascular damage. The pathophysiological changes might be due to the activation of proinflammatory Th2 cells, profibrotic M2 macrophages, B cells, fibroblasts, and endothelial cells. Here, we review the studies focused on NLRP3 inflammasome activation, its association with innate and adaptive immune cells, endothelium injury, and differentiation of fibroblasts in SSc. Furthermore, we summarize the prospect of therapy targeting NLRP3 pathway.

Non-coding RNAs in necroptosis, pyroptosis, and ferroptosis in cardiovascular diseases

Accumulating evidence has proved that non-coding RNAs (ncRNAs) play a critical role in the genetic programming and gene regulation of cardiovascular diseases (CVDs). Cardiovascular disease morbidity and mortality are rising and have become a primary public health issue that requires immediate resolution through effective intervention. Numerous studies have revealed that new types of cell death, such as pyroptosis, necroptosis, and ferroptosis, play critical cellular roles in CVD progression. It is worth noting that ncRNAs are critical novel regulators of cardiovascular risk factors and cell functions by mediating pyroptosis, necroptosis, and ferroptosis. Thus, ncRNAs can be regarded as promising therapeutic targets for treating and diagnosing cardiovascular diseases. Recently, there has been a surge of interest in the mediation of ncRNAs on three types of cell death in regulating tissue homeostasis and pathophysiological conditions in CVDs. Although our understanding of ncRNAs remains in its infancy, the studies reviewed here may provide important new insights into how ncRNAs interact with CVDs. This review summarizes what is known about the functions of ncRNAs in modulating cell death-associated CVDs and their role in CVDs, as well as their current limitations and future prospects.

NLRP3 Inflammasome as a Therapeutic Target for Atherosclerosis: A Focus on Potassium Outflow

Atherosclerosis is a risk factor for various cardiovascular diseases, and is linked to high rates of morbidity and mortality across the globe. Although numerous complex processes are involved in the development and progression of atherosclerosis, the exact mechanisms behind its pathogenesis remain unclear. Inflammation and endothelial cell damage exert a lasting effect on atherosclerosis, causing lipid and fibrous tissue accumulation in the intima of the artery to form plaques, and subsequently promoting atherosclerosis. Nod-like receptor protein 3 (NLRP3) inflammatory corpuscle is thought to be the link between lipid metabolism and inflammation. Long Potassium outflow is a vital activator of NLRP3, with a simultaneous effect as a start-up and adjustment. The majority of existing drugs for atherosclerosis targeting the NLRP3 signaling pathway target IL-1, whereas drugs targeting the critical link of potassium efflux are relatively new. This review discusses the NLRP3 inflammatory corpuscle as a critical regulator of the immunological inflammatory pathway in atherosclerosis. Moreover, current knowledge on NLRP3 inflammatory corpuscle start and activation pathways were integrated, emphasizing potassium-involved outflow-related proteins. We highlight potential treatment approaches for NLRP3 inflammatory corpuscle pathways, specifically targeting potassium outflow channels of targeted drugs. Collectively, these insights indicate that targeting the NLRP3 inflammatory corpuscle is a vital anti-inflammatory therapy for treating atherosclerosis.

Antioxidant Systems, lncRNAs, and Tunneling Nanotubes in Cell Death Rescue from Cigarette Smoke Exposure

Cigarette smoke is a rich source of carcinogens and reactive oxygen species (ROS) that can damage macromolecules including DNA. Repair systems can restore DNA integrity. Depending on the duration or intensity of stress signals, cells may utilize various survival and adaptive mechanisms. ROS levels are kept in check through redundant detoxification processes controlled largely by antioxidant systems. This review covers and expands on the mechanisms available to cigarette smoke-exposed cancer cells for restoring the redox balance. These include multiple layers of transcriptional control, each of which is posited to be activated upon reaching a particular stress threshold, among them the NRF2 pathway, the AP-1 and NF-kB pathways, and, finally, TP53, which triggers apoptosis if extreme toxicity is reached. The review also discusses long noncoding RNAs, which have been implicated recently in regulating oxidative stress-with roles in ROS detoxification, the inflammatory response, oxidative stress-induced apoptosis, and mitochondrial oxidative phosphorylation. Lastly, the emerging roles of tunneling nanotubes in providing additional mechanisms for metabolic rescue and the regulation of redox imbalance are considered, further highlighting the expanded redox reset arsenal available to cells.

The role of NLRP3 inflammasome in psychotropic drug-induced hepatotoxicity

Increased medical application of psychotropic drugs raised attention concerning their toxicological effects. In fact, more than 160 psychotropic drugs including antidepressants and antipsychotics, have been shown to cause liver side effects, but the underlying mechanisms are still poorly understood. Here, we discovered that fluoxetine, a common antidepressant, was specifically sensed by NLRP3 inflammasome, whose subsequent activation resulted in the maturation of caspase-1 and IL-1β, as well as gasdermin D (GSDMD) cleavage, which could be completely abrogated by a selective NLRP3 inhibitor MCC950 or Nlrp3 knockout (Nlrp3^−/−). Mechanistically, mitochondrial damage and the subsequent mitochondrial reactive oxygen species (mtROS) accumulation were crucial upstream signaling events in fluoxetine-triggered NLRP3 inflammasome activation. In fluoxetine hepatotoxicity models, mice showed the alterations of aminotransferase levels, hepatic inflammation and hepatocyte death in an NLRP3-dependent manner, and MCC950 pretreatment could reverse these side effects of fluoxetine. Notably, we also found that multiple antidepressants, such as amitriptyline, paroxetine, and imipramine, and antipsychotics, such as asenapine, could specifically trigger the NLRP3 inflammasome activation. Collectively, our findings implicate multiple psychotropic drugs may act as danger signals sensed by the NLRP3 inflammasome and result in hepatic injury.

A Multifunctional Vanadium-Iron-Oxide Nanoparticle Eradicates Hepatocellular Carcinoma via Targeting Tumor and Endothelial Cells

Nanoparticles are widely used in biological research and cancer therapy. In hepatocellular carcinoma, several nanoplatforms have been synthesized and studied to improve the drug efficacy; however, these nanoplatforms are still insufficient to eradicate tumors. Herein, we have synthesized a novel vanadium (V)-iron-oxide (ION) nanoparticle (VIO) that combines chemodynamic, photothermal, and diagnostic capacities to enhance the tumor suppression effect in one agent with multiple functions. In the in vitro models, hepatocellular carcinoma cells are significantly inhibited by VIO-based nanoagents. The mechanistic study validates that VIO increases reactive oxygen species (ROS), which led to apoptosis and ferroptosis resulting in cell death. To our surprise, VIO targets not only tumor cells but also endothelial cells. In addition to inducing cell death, VIO also blocks tube formation and cell migration in human umbilical vein endothelial cell (HUVEC) and C166 models, indicating an antiangiogenic potential. In mouse tumor models, VIO retards tumor growth and induces apoptosis in tumor tissues. Furthermore, a significant blood vessel regression is seen in VIO-treated groups accompanied with larger necrotic areas. More interestingly, the activation of photothermal therapy completely eradicates tumor tissues. Taken together, this VIO nanoplatform could be a powerful anticancer candidate for nanodrug development.

Substance P promotes the progression of bronchial asthma through activating the PI3K/AKT/NF-κB pathway mediated cellular inflammation and pyroptotic cell death in bronchial epithelial cells

NOD-like receptor family pyrin domain containing three (NLRP3) inflammasome-mediated pyroptotic cell death and inflammation contribute to the pathogenesis of bronchial asthma, and it is reported that Substance P (SP) plays important role in the process, however, the detailed molecular mechanisms by which SP participates in the aggravation of bronchial asthma have not been fully studied. Here, our clinical data showed that SP and its receptor Neurokinin-1 receptor (NK1R) were significantly elevated in the plasma and peripheral blood mononuclear cell (PBMC) collected from patients with bronchial asthma, and further pre-clinical experiments evidenced that SP suppressed cell viability, accelerated lactate dehydrogenase (LDH) release, and upregulated ASC, Caspase-1, NLRP3, IL-1β and IL-18 to promote pyroptotic cell death and cellular inflammation in the human bronchial epithelial cells and asthmatic mice models in vitro and in vivo. Interestingly, SP-induced pyroptotic cell death was reversed by NK1R inhibitor L732138. Then, we uncovered the underlying mechanisms, and found that SP activated the downstream PI3K/AKT/NF-κB signal pathway in a NK1R-dependent manner, and blockage of this pathway by both PI3K inhibitor (LY294002) and NF-κB inhibitor (MG132) reversed SP-induced pyroptotic cell death and recovered cell viability in bronchial epithelial cells. Collectively, we concluded that SP interacted with its receptor NK1R to activate the PI3K/AKT/NF-κB pathway, which further triggered NLRP3-mediated pyroptotic cell death in the bronchial epithelial cells, resulting in the aggravation of bronchial asthma.

Evidence for the Benefits of Melatonin in Cardiovascular Disease

The pineal gland is a neuroendocrine gland which produces melatonin, a neuroendocrine hormone with critical physiological roles in the circadian rhythm and sleep-wake cycle. Melatonin has been shown to possess anti-oxidant activity and neuroprotective properties. Numerous studies have shown that melatonin has significant functions in cardiovascular disease, and may have anti-aging properties. The ability of melatonin to decrease primary hypertension needs to be more extensively evaluated. Melatonin has shown significant benefits in reducing cardiac pathology, and preventing the death of cardiac muscle in response to ischemia-reperfusion in rodent species. Moreover, melatonin may also prevent the hypertrophy of the heart muscle under some circumstances, which in turn would lessen the development of heart failure. Several currently used conventional drugs show cardiotoxicity as an adverse effect. Recent rodent studies have shown that melatonin acts as an anti-oxidant and is effective in suppressing heart damage mediated by pharmacologic drugs. Therefore, melatonin has been shown to have cardioprotective activity in multiple animal and human studies. Herein, we summarize the most established benefits of melatonin in the cardiovascular system with a focus on the molecular mechanisms of action.

Cadmium mediates pyroptosis of human dermal lymphatic endothelial cells in a NLRP3 inflammasome-dependent manner

Pyroptosis is a form of inflammasome-trigged programmed cell death in response to a variety of stimulators, including environmental cytotoxic pollutant Cadmium (Cd). Vascular endothelial cell is one of the first-line cell types of Cd cell toxicity. Studies report that Cd exposure causes pyroptosis in vascular endothelial cells. Vascular and lymphatic endothelial cells have many common properties, but these two cell types are distinguished in gene expression profile and the responsive behaviors to chemokine or physical stimulations. Whether Cd exposure also causes pyroptosis in lymphatic endothelial cells has not been investigated. Here, we found that Cd treatment significantly decreased the viability of human dermal lymphatic endothelial cells (HDLECs). Cd treatment induced inflammasome activation indicated by elevated cleavage of pro-caspase-1 into active form Casp1p20, elevated secretion of pro-inflammatory cytokines and production of reactive oxygen species (ROS). Flow cytometry showed that caspase-1 activity was significantly increased in Cd-treated cells. Moreover, knockdown of NLRP3 effectively rescued Cd-induced inflammasome activation and pyroptosis in HDLECs. Collectively, our results indicated that Cd induced pyroptosis in a NLRP3 inflammasome-dependent manner in lymphatic endothelial cells.

The hydrogen storage nanomaterial MgH2 improves irradiation-induced male fertility impairment by suppressing oxidative stress

OBJECTIVE

This study aimed to reveal the protective effect of hydrogen storage nanomaterial MgH₂ on radiation-induced male fertility impairment.

METHODS

The characterization of MgH₂ were analyzed by scanning electron microscopy (SEM) and particle size analyzer. The safety of MgH₂ were evaluated in vivo and in vitro. The radioprotective effect of MgH₂ on the reproductive system were analyzed in mice, including sperm quality, genetic effect, spermatogenesis, and hormone secretion. ESR, flow cytometry and western blotting assay were used to reveal the underlying mechanisms.

RESULTS

MgH₂ had an irregular spherical morphology and a particle size of approximately 463.2 nm, and the content of Mg reached 71.46%. MgH₂ was safe and nontoxic in mice and cells. After irradiation, MgH₂ treatment significantly protected testicular structure, increased sperm density, improved sperm motility, reduced deformity rates, and reduced the genetic toxicity. Particularly, the sperm motility were consistent with those in MH mice and human semen samples. Furthermore, MgH₂ treatment could maintain hormone secretion and testicular spermatogenesis, especially the generation of Sertoli cells, spermatogonia and round sperm cells. In vitro, MgH₂ eliminated the [·OH], suppressed the irradiation-induced increase in ROS production, and effectively alleviated the increase in MDA contents. Moreover, MgH₂ significantly ameliorated apoptosis in testes and cells and reversed the G2/M phase cell cycle arrest induced by irradiation. In addition, MgH₂ inhibited the activation of radiation-induced inflammation and pyroptosis.

CONCLUSION

MgH₂ improved irradiation-induced male fertility impairment by eliminating hydroxyl free radicals. Mice fertility and function were evaluated with or without MgH₂ treatment after 5 Gy irradiation. MgH₂ had the ability of hydroxyl radicals scavenging and MDA suppressing in testicular tissue induced by irradiation. Further, MgH₂ could participate in spermatogenesis and protect sperm development in three stages: the generation of Sertoli cells (Sox-9+), spermatogonia (Stra8+) and round sperm cells (Crem+). Moreover, MgH₂ alleviated the decrease of testosterone secreted by interstitial cells after irradiation. In addition, MgH₂ suppressed apoptosis, pyroptosis and inflammatory response and alleviated cell cycle arrest by mediating IR-induced ROS.

Gasdermin D Deficiency Limits the Transition of Atherosclerotic Plaques to an Inflammatory Phenotype in ApoE Knock-Out Mice

Gasdermin D (GSDMD) is the key executor of pyroptotic cell death. Recent studies suggest that GSDMD-mediated pyroptosis is involved in atherosclerotic plaque destabilization. We report that cleaved GSDMD is expressed in macrophage- and smooth muscle cell-rich areas of human plaques. To determine the effects of GSDMD deficiency on atherogenesis, ApoE^−/− Gsdmd^−/− (n = 16) and ApoE^−/−Gsdmd^+/+ (n = 18) mice were fed a western-type diet for 16 weeks. Plaque initiation and formation of stable proximal aortic plaques were not altered. However, plaques in the brachiocephalic artery (representing more advanced lesions compared to aortic plaques) of ApoE^−/− Gsdmd^−/− mice were significantly smaller (115 ± 18 vs. 186 ± 16 × 10³ µm², p = 0.006) and showed features of increased stability, such as decreased necrotic core area (19 ± 4 vs. 37 ± 7 × 10³ µm², p = 0.03) and increased αSMA/MAC3 ratio (1.6 ± 0.3 vs. 0.7 ± 0.1, p = 0.01), which was also observed in proximal aortic plaques. Interestingly, a significant increase in TUNEL positive cells was observed in brachiocephalic artery plaques from ApoE^−/− Gsdmd^−/− mice (141 ± 25 vs. 62 ± 8 cells/mm², p = 0.005), indicating a switch to apoptosis. This switch from pyroptosis to apoptosis was also observed in vitro in Gsdmd^−/− macrophages. In conclusion, targeting GSDMD appears to be a promising approach for limiting the transition to an inflammatory, vulnerable plaque phenotype.

Ginsenosides Rb1 Attenuates Chronic Social Defeat Stress-Induced Depressive Behavior via Regulation of SIRT1-NLRP3/Nrf2 Pathways

Ginsenoside Rb1, a diol-type ginseng saponin, has various positive effects on the central nervous system. This study aimed to evaluate the antidepressant effects of Rb1 on chronic social defeat stress (CSDS) induced behavioral deficits and the exact neural cascades linked with inflammatory processes. The results of behavioral tests such as social interaction, tail suspension, and forced swimming revealed that oral treatment of Rb1 (35 and 70 mg/kg) alleviates depression-like behavior. Rb1 treatment increased antioxidant enzyme activity (SOD and CAT) and reduced lipid peroxidation (LPO) content in the hippocampus. Rb1 also suppressed the production of inflammatory cytokines (TNF-α, IL-18, and IL-1β) as well as microglial activation (Iba1) in response to CSDS. Moreover, Rb1 administration considerably reduced the protein expression of NLRP3 (inflammasome) and promoted the protein expressions of Nrf2, HO-1 and Sirtuin1(SIRT1) activation in the hippocampus. Our findings showed that Rb1 effectively restores the depressive-like behavior in CSDS-induced model mice, mediated in part by the normalization of oxidative stress levels. The suppression of neuroinflammation is mediated by the regulation of SIRT1-NLRP3/Nrf2 pathways. Our results asserted that the Rb1 is a novel therapeutic candidate for treating depression.

Mitochondrial damage and activation of the cytosolic DNA sensor cGAS-STING pathway lead to cardiac pyroptosis and hypertrophy in diabetic cardiomyopathy mice

Diabetic cardiomyopathy (DCM) is a serious cardiac complication of diabetes that currently lacks specific treatment. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway has been suggested to contribute to the pathogenesis of cardiovascular diseases. However, whether cGAS-STING is involved in the development of DCM has not been established. Our study aimed to determine the role of cGAS-STING in the initiation of nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome-induced cardiac pyroptosis and chronic inflammation during the pathogenesis of DCM. C57BL/6J mice were preinjected with adeno-associated virus 9 (AAV9) intravenously via the tail vein to specifically knock down myocardial STING. After four weeks, mice with myocardium-specific knockdown of STING received injections of streptozotocin (STZ; 50 mg/kg) and a high-fat diet to induce diabetes. Measurements included echocardiography, immunohistochemical analyses, wheat germ agglutinin (WGA) staining, and western blotting. Here, we showed that the cGAS-STING signaling pathway was activated in diabetic hearts, which was indicated by the increased phosphorylation of TANK-binding kinase 1 (TBK1) and interferon (IFN) regulatory factor 3 (IRF3), leading to the activation of the NLRP3 inflammasome in the hearts of diabetic mice and proinflammatory cytokine release into serum. Moreover, STING knockdown via adeno-associated virus-9 (AAV9) in diabetic mouse heart alleviated cardiac pyroptosis and the inflammatory response, prevented diabetes-induced hypertrophy, and restored cardiac function. Mechanistically, we showed that palmitic acid (PA)-induced lipotoxicity impairs mitochondrial homeostasis, producing excessive mitochondrial reactive oxygen species (mtROS), which results in oxidative damage to mitochondrial DNA (mtDNA) and its release into the cytoplasm while switching on cGAS-STING-mediated pyroptosis in cardiomyocytes, thereby worsening the progression of diabetic cardiomyopathy. Our study demonstrated that activation of the cGAS-STING pathway caused by mitochondrial oxidative damage and mtDNA escape induced by free fatty acids promoted pyroptosis and proinflammatory responses in cardiomyocytes in a NLRP3 inflammasome-dependent manner, thus promoting myocardial hypertrophy during the progression of DCM.

Sulforaphane Suppresses the Nicotine-Induced Expression of the Matrix Metalloproteinase-9 via Inhibiting ROS-Mediated AP-1 and NF-κB Signaling in Human Gastric Cancer Cells

Sulforaphane, a natural phytochemical compound found in various cruciferous vegetables, has been discovered to present anti-cancer properties. Matrix metalloproteinase-9 (MMP-9) plays a crucial role in gastric cancer metastasis. However, the role of sulforaphane in MMP-9 expression in gastric cancer is not yet defined. Nicotine, a psychoactive alkaloid found in tobacco, is associated with the development of gastric cancer. Here, we found that sulforaphane suppresses the nicotine-mediated induction of MMP-9 in human gastric cancer cells. We discovered that reactive oxygen species (ROS) and MAPKs (p38 MAPK, Erk1/2) are involved in nicotine-induced MMP-9 expression. AP-1 and NF-κB are the critical transcription factors in MMP-9 expression. ROS/MAPK (p38 MAPK, Erk1/2) and ROS functioned as upstream signaling of AP-1 and NF-κB, respectively. Sulforaphane suppresses the nicotine-induced MMP-9 by inhibiting ROS-mediated MAPK (p38 MAPK, Erk1/2)/AP-1 and ROS-mediated NF-κB signaling axes, which in turn inhibit cell invasion in human gastric cancer AGS cells. Therefore, the current study provides valuable evidence for developing sulforaphane as a new anti-invasion strategy for human gastric cancer therapy.

Dietary Fatty Acid Regulation of the NLRP3 Inflammasome via the TLR4/NF-κB Signaling Pathway Affects Chondrocyte Pyroptosis

Dietary fatty acid (FA) content and type have different effects on obesity-associated osteoarthritis (OA), but the mechanisms underlying these differences are not fully understood. Inflammation activated by toll-like receptor 4 (TLR4)/nuclear factor- (NF-) κB signaling and pyroptosis induced by the NLRP3/caspase-1/gasdermin D (GSDMD) signaling pathway play important roles in OA development. Our aim in this study was to observe the effects of dietary FAs on the articular cartilage of obese post-traumatic OA model mice and on chondrocytes stimulated by lipopolysaccharide (LPS) and to determine whether the underlying mechanisms involve TLR4/NF-κB and NLRP3/caspase-1/GSDMD signaling pathways. Mice were fed high-fat diets rich in various FAs and underwent surgical destabilization of the medial meniscus to establish the obesity-related post-traumatic OA model. LPS-induced SW1353 chondrosarcoma cells were used to mimic OA status in vitro, and TLR4 inhibitors or TLR4 overexpressing lentivirus was administered. Analysis using weight-matched mice and multiple regression models revealed that OA was associated with dietary FA content and serum inflammatory factor levels, but not body weight. Diets rich in n-3 polyunsaturated fatty acids (PUFAs) attenuated OA and inhibited the TLR4/NF-κB and NLRP3/caspase-1/GSDMD signaling pathways, whereas diets rich in saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), or n-6 PUFAs increased OA severity and activated these pathways. In vitro results for SFAs, n-6 PUFAs, and n-3 PUFAs were consistent with the animal experiments. However, those for MUFAs were not. FA effects on the NLRP3/caspase-1/GSDMD pathway were associated with the inhibition or activation of the TLR4 signaling pathway. In conclusion, diets rich in SFAs or n-6 PUFAs can exacerbate obesity-associated OA, whereas those rich in n-3 PUFAs have protective effects against this disease, due to their respective pro-/anti-inflammatory and pyroptotic effects. Further research on dietary FA supplements as a potential therapeutic approach for OA is needed.

Mitofilin Mitigates Myocardial Damage in Acute Myocardial Infarction by Regulating Pyroptosis of Cardiomyocytes

Background

Acute myocardial infarction (AMI) can lead to sudden cardiac death after prolonged ischemia or heart failure (HF) and impaired left ventricular pump function. However, the underlying mechanism remains largely unknown. The purpose of this study was to investigate the role of mitofilin in alleviating AMI.

Methods

Recombinant adenoviral vectors for mitofilin overexpression or mitofilin knockdown were constructed, respectively. A mouse AMI model was established and the effect of mitofilin on myocardial pyroptosis was examined by detecting the lactate dehydrogenase (LDH) level and inflammatory factors. Moreover, a cellular model of AMI was established by treating cardiomyocytes with hypoxia/reoxygenation (H/R). An enzyme-linked immunosorbent assay (ELISA) and a western blot analysis were used to detect the effect of mitofilin knockdown on the expression of pyroptosis-related factors. Furthermore, the regulatory role of mitofilin in PI3K/AKT pathway was evaluated by the western blot and PI3K inhibitor.

Results

Mitofilin was downregulated in the heart tissue of the AMI mice and H/R induced cardiomyocytes. The overexpression of mitofilin significantly alleviated AMI and reduced pyroptosis-related factors. Meanwhile, in cardiomyocytes, mitofilin knockdown aggravated cellular damages by promoting pyroptosis. Further analysis showed that the anti-pyroptotic effect of mitofilin was dependent on the activation of the PI3K/AKT signaling pathway.

Conclusions

Our study suggests that mitofilin regulates pyroptosis through the PI3K/AKT signaling pathway in cardiomyocytes to ameliorate AMI, which may serve as a therapeutic strategy for the management of AMI.

Procyanidin B2 Attenuates Nicotine-Induced Hepatocyte Pyroptosis through a PPARγ-Dependent Mechanism

Procyanidin B2 (PCB2), a natural flavonoid, has been demonstrated to exert anti-oxidation and anti-inflammatory effects on hepatic diseases. Increasing evidence shows the hepatoxicity of nicotine. However, whether PCB2 protects against nicotine-induced hepatoxicity and the underlying mechanisms remains uncharacterized. Here, we reported that nicotine promoted hepatocyte pyroptosis, as evidenced by the elevation of propidium iodide (PI)-positive cells, the activation of Caspase-1 and gasdermin D (GSDMD), the enhanced expression of NOD-like receptor containing pyrin domain 3 (NLRP3) and the increased release of lactate dehydrogenase (LDH), interleukin (IL)-1β and IL-18. The silencing of GSDMD by small interfering RNA (siRNA) efficiently inhibited the release of LDH and the secretion of IL-1β and IL-18. In addition, rosiglitazone (RGZ) prevented hepatocyte pyroptosis induced by nicotine. Furthermore, we showed that PCB2 attenuated nicotine-induced pyroptosis through the activation of peroxisome proliferator-activated receptor-γ (PPARγ) in hepatocytes. Moreover, administration of PCB2 ameliorated liver injury and hepatocyte pyroptosis in nicotine-treated mice. Hence, our findings demonstrated that PCB2 attenuated pyroptosis and liver damage in a PPARγ-dependent manner. Our results suggest a new mechanism by which PCB2 exerts its liver protective effects.

Regulation of Pyroptosis by ncRNA: A Novel Research Direction

Pyroptosis is a novel form of programmed cell death (PCD), which is characterized by DNA fragmentation, chromatin condensation, cell swelling and leakage of cell contents. The process of pyroptosis is performed by certain inflammasome and executor gasdermin family member. Previous researches have manifested that pyroptosis is closely related to human diseases (such as inflammatory diseases) and malignant tumors, while the regulation mechanism of pyroptosis is not yet clear. Non-coding RNA (ncRNA) such as microRNA (miRNA), long non-coding RNA (lncRNA) and circular RNA (circRNA) have been widely identified in the genome of eukaryotes and played a paramount role in the development of cell function and fate after transcription. Accumulating evidences support the importance of ncRNA biology in the hallmarks of pyroptosis. However, the associations between ncRNA and pyroptosis are rarely reviewed. In this review, we are trying to summarize the regulation and function of ncRNA in cell pyroptosis, which provides a new research direction and ideas for the study of pyroptosis in different diseases.

NLRP3-Mediated Inflammation in Atherosclerosis and Associated Therapeutics

The NLRP3 inflammasome is a crucial constituent of the body’s innate immune system, and a multiprotein platform which is initiated by pattern recognition receptors (PRRs). Its activation leads to caspase-1 maturation and release of inflammatory cytokines, interleukin-1β (IL-1β) and IL-18, and subsequently causes pyroptosis. Recently, the excess activation of NLRP3 inflammasome has been confirmed to mediate inflammatory responses and to participate in genesis and development of atherosclerosis. Therefore, the progress on the discovery of specific inhibitors against the NLRP3 inflammasome and the upstream and downstream inflammatory factors has become potential targets for clinical treatment. Here we review the recently described mechanisms about the NLRP3 inflammasome activation, and discuss emphatically the pharmacological interventions using statins and natural medication for atherosclerosis associated with NLRP3 inflammasome.

Irisin Suppresses Nicotine-Mediated Atherosclerosis by Attenuating Endothelial Cell Migration, Proliferation, Cell Cycle Arrest, and Cell Senescence

Atherosclerotic disease has become the major cause of death worldwide. Smoking, as a widespread independent risk factor, further strengthens the health burden of atherosclerosis. Irisin is a cytokine that increases after physical activity and shows an atheroprotective effect, while its specific mechanism in the process of atherosclerosis is little known. The reversal effect of irisin on intimal thickening induced by smoking-mediated atherosclerosis was identified in Apoe^–/– mice through the integrin αVβ5 receptor. Endothelial cells treated with nicotine and irisin were further subjected to RNA-seq for further illustrating the potential mechanism of irisin in atherosclerosis, as well as the wound healing assays, CCK-8 assays, β-gal staining and cell cycle determination to confirm phenotypic alterations. Endothelial differential expressed gene enrichment showed focal adhesion for migration and proliferation, as well as the P53 signaling pathway for cell senescence and cell cycle control. Irisin exerts antagonistic effects on nicotine-mediated migration and proliferation via the integrin αVβ5/PI3K pathway. In addition, irisin inhibits nicotine-mediated endothelial senescence and cell cycle arrest in G0/G1 phase via P53/P21 pathway. This study further illustrates the molecular mechanism of irisin in atherosclerosis and stresses its potential as an anti-atherosclerotic therapy.

Pharmacological mechanism of Shenlingbaizhu formula against experimental colitis

BACKGROUND

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) characterized by an overactive immune response and destruction of the colorectal epithelium with intricate pathological factors. Shenlingbaizhu (SLBZ) formula, included in the Chinese Pharmacopoeia 2020, has been widely utilized to treat UC.

PURPOSE

The present study was designed to uncover the underlying molecular mechanisms of SLBZ formula against UC.

METHODS

A murine model of experimental colitis was established by orally feeding 2% dextran sodium sulfate (DSS) to mice for 7 days, followed by SLBA treatment for the next 15 days. Network pharmacology analysis was performed to predict the pharmacological mechanisms. High-throughput 16S rRNA sequencing integrated with liquid chromatography-mass spectrometry (LC-MS) was conducted on mouse stool in order to determine alterations in the composition of the intestinal microbiota and metabolites. Western blotting, immunofluorescence, and flow cytometry were performed to examine the anti-inflammatory role of SLBZ.

RESULTS

DSS treatment induced experimental colitis, and this induction was alleviated by SLBZ treatment, as evidenced by rescued pathological symptoms in the experimental colitis mouse groups. Network pharmacology analysis showed that SLBZ-target genes were enriched in pathogen-induced infectious and inflammatory pathways, as well as neoplastic processes. SLBZ administration also modulated the gut microbiota composition and metabolic profiles of experimental colitis mice and alleviated the progression of experimental colitis. We further showed via in-vitro experiments that SLBZ suppressed macrophage (Mφ) transition to pro-inflammatory phenotype (M1), rescued tumor necrosis factor-α (TNFα)-induced pyroptosis of intestinal organoids (IOs), and decreased the recruitment of Mφs by epithelial cells.

CONCLUSION

SLBZ formula is an effective treatment for murine colitis and showed a stronger therapeutic capacity than melasazine. The pharmacological mechanisms of SLBZ involve the re-establishment of an anti-inflammatory milieu and healthy microbiome, which favors mucosal healing.

CagA+Helicobacter pylori, Not CagA–Helicobacter pylori, Infection Impairs Endothelial Function Through Exosomes-Mediated ROS Formation

Background

Helicobacter pylori (H. pylori) infection increases the risk for atherosclerosis, and ROS are critical to endothelial dysfunction and atherosclerosis. CagA is a major H. pylori virulence factor associated with atherosclerosis. The present study aimed to test the hypothesis that CagA+H. pylori effectively colonizes gastric mucosa, and CagA+H. pylori, but not CagA–H. pylori, infection impairs endothelial function through exosomes-mediated ROS formation.

Methods

C57BL/6 were used to determine the colonization ability of CagA+H. pylori and CagA–H. pylori. ROS production, endothelial function of thoracic aorta and atherosclerosis were measured in CagA+H. pylori and CagA–H. pylori infected mice. Exosomes from CagA+H. pylori and CagA–H. pylori or without H. pylori infected mouse serum or GES-1 were isolated and co-cultured with bEND.3 and HUVECs to determine how CagA+H. pylori infection impairs endothelial function. Further, GW4869 was used to determine if CagA+H. pylori infection could lead to endothelial dysfunction and atherosclerosis through an exosomes-mediated mechanism.

Results

CagA+H. pylori colonized gastric mucosa more effectively than CagA–H. pylori in mice. CagA+H. pylori, not CagA–H. pylori, infection significantly increased aortic ROS production, decreased ACh-induced aortic relaxation, and enhanced early atherosclerosis formation, which were prevented with N-acetylcysteine treatment. Treatment with CagA-containing exosomes significantly increased intracellular ROS production in endothelial cells and impaired their function. Inhibition of exosomes secretion with GW4869 effectively prevented excessive aortic ROS production, endothelial dysfunction, and atherosclerosis in mice with CagA+H. pylori infection.

Conclusion

These data suggest that CagA+H. pylori effectively colonizes gastric mucosa, impairs endothelial function, and enhances atherosclerosis via exosomes-mediated ROS formation in mice.

Irisin protects against vascular calcification by activating autophagy and inhibiting NLRP3-mediated vascular smooth muscle cell pyroptosis in chronic kidney disease

Irisin protects the cardiovascular system against vascular diseases. However, its role in chronic kidney disease (CKD) -associated vascular calcification (VC) and the underlying mechanisms remain unclear. In the present study, we investigated the potential link among Irisin, pyroptosis, and VC under CKD conditions. During mouse vascular smooth muscle cell (VSMC) calcification induced by β-glycerophosphate (β-GP), the pyroptosis level was increased, as evidenced by the upregulated expression of pyroptosis-related proteins (cleaved CASP1, GSDMD-N, and IL1B) and pyroptotic cell death (increased numbers of PI-positive cells and LDH release). Reducing the pyroptosis levels by a CASP1 inhibitor remarkably decreased calcium deposition in β-GP-treated VSMCs. Further experiments revealed that the pyroptosis pathway was activated by excessive reactive oxygen species (ROS) production and subsequent NLR family pyrin domain containing 3 (NLRP3) inflammasome activation in calcified VSMCs. Importantly, Irisin effectively inhibited β-GP-induced calcium deposition in VSMCs in vitro and in mice aortic rings ex vivo. Overexpression of Nlrp3 attenuated the suppressive effect of Irisin on VSMC calcification. In addition, Irisin could induce autophagy and restore autophagic flux in calcified VSMCs. Adding the autophagy inhibitor 3-methyladenine or chloroquine attenuated the inhibitory effect of Irisin on β-GP-induced ROS production, NLRP3 inflammasome activation, pyroptosis, and calcification in VSMCs. Finally, our in vivo study showed that Irisin treatment promoted autophagy, downregulated ROS level and thereby suppressed pyroptosis and medial calcification in aortic tissues of adenine-induced CKD mice. Together, our findings for the first time demonstrated that Irisin protected against VC via inducing autophagy and inhibiting VSMC pyroptosis in CKD, and Irisin might serve as an effective therapeutic agent for CKD-associated VC.

SIRT1 alleviates IL-1β induced nucleus pulposus cells pyroptosis via mitophagy in intervertebral disc degeneration

Inflammatory stress of nucleus pulposus cells (NPCs) plays an important role in the pathogenesis of intervertebral disc degeneration (IVDD). Pyroptosis and NLRP3 inflammasome activation have been reported aggravating IVDD. SIRT1 is essential for mammalian cell survival and longevity by participating in various cellular processes. However, few studies analyzed the potential mechanism of SIRT1 in NLRP3- activated pyroptosis in NPCs. In this study, we confirmed that IL-1β could induce pyroptosis and NLRP3 inflammation activation, meanwhile, resulted in mitochondrial oxidative stress injury and dysfunction in NPCs. When the mitochondrial ROS was inhibited by Mito-Tempo, the pyroptosis and NLRP3 inflammation activation was also inhibited. SIRT1 overexpression could ameliorate IL-1β induced mitochondrial dysfunction and ROS accumulation, inhibit NLRP3 inflammasome activation by promoting PINK1/Parkin mediated mitophagy, however, these protective phenomena reversed by autophagy inhibitor 3-MA pretreatment. In vivo, SIRT1 agonist (SRT1720) treatment decreased the expression of NLRP3, p20, and IL-1β, increased the expression of PINK1 and LC3, delayed IVDD process in the rat model. Taken together, our results indicate that SIRT1 alleviates IL-1β induced NLRP3 inflammasome activation via mitophagy in NPCs, SIRT1 may be a potential therapeutic target to alleviate NLRP3- activated pyroptosis in the inflammatory stress related IVDD.

Tricalcium phosphate particles promote pyroptotic death of calvaria osteocytes through the ROS/NLRP3/Caspase-1 signaling axis in amouse osteolysis model

Wear particles-induced inflammatory osteolysis, a major factor of aseptic loosening affects the long-term survival of orthopedic prostheses. Increasing observations have demonstrated that osteocytes, making up over 95% of all the bone cells, is involved in wear particle-induced periprosthetic osteolysis, but its mechanism remains unclear. In the present study, we embedded micro-sized tricalcium phosphate (TCP) particles (30 mg) under the periosteum around the middle suture of the mouse calvaria to establish a calvarial osteolysis model and investigated the biological effects of the particles on calvaria osteocytes in vivo. Results showed that TCP particles induced pyroptosis and activated the NLRP3 inflammasome in calvaria osteocytes, which was confirmed by obvious increases in empty lacunae, protein expressions of speck-like protein containing CARD (ASC), NOD-like receptor protein 3 (NLRP3), cleaved caspase-1 (Casp-1 p20) and cleaved gasdermin D (GSDMD-N), and resulted in elevated ratios of Casp-1 p20/Casp-1 and interleukin (IL)-1β/pro-IL-1β. Simultaneously, TCP particles enhanced serum levels of lactate dehydrogenase (LDH) and IL-1β. Furthermore, the pyroptotic effect was reversed by the Casp-1 inhibitor VX765 or the NLRP3 inhibitor MCC950. In addition, TCP particles increased the levels of intracellular reactive oxygen species (ROS) and malonaldehyde (MDA), whereas decreased the antioxidant enzyme nuclear factor E2-related factor 2 (Nrf2) level, leading to oxidative stress in calvaria osteocytes; the ROS scavenger N-acetylcysteine (NAC) attenuated these effects of pyroptotic death and the NLPR3 activation triggered by TCP particles. Collectively, our data suggested that TCP particles promote pyroptotic death of calvaria osteocytes through the ROS/NLRP3/Caspase-1 signaling axis, contributing to osteoclastogenesis and periprosthetic osteolysis.

Mitochondria Related Cell Death Modalities and Disease

Mitochondria are well known as the centre of energy metabolism in eukaryotic cells. However, they can not only generate ATP through the tricarboxylic acid cycle and oxidative phosphorylation but also control the mode of cell death through various mechanisms, especially regulated cell death (RCD), such as apoptosis, mitophagy, NETosis, pyroptosis, necroptosis, entosis, parthanatos, ferroptosis, alkaliptosis, autosis, clockophagy and oxeiptosis. These mitochondria-associated modes of cell death can lead to a variety of diseases. During cell growth, these modes of cell death are programmed, meaning that they can be induced or predicted. Mitochondria-based treatments have been shown to be effective in many trials. Therefore, mitochondria have great potential for the treatment of many diseases. In this review, we discuss how mitochondria are involved in modes of cell death, as well as basic research and the latest clinical progress in related fields. We also detail a variety of organ system diseases related to mitochondria, including nervous system diseases, cardiovascular diseases, digestive system diseases, respiratory diseases, endocrine diseases, urinary system diseases and cancer. We highlight the role that mitochondria play in these diseases and suggest possible therapeutic directions as well as pressing issues that need to be addressed today. Because of the key role of mitochondria in cell death, a comprehensive understanding of mitochondria can help provide more effective strategies for clinical treatment.

Activation of pyroptosis and ferroptosis is involved in the hepatotoxicity induced by polystyrene microplastics in mice

Microplastics (MPs) are new environmental pollutants and have received widespread attention in recent years, but the toxicity of the MPs remains to be fully elucidated. To explore the effect of MPs on hepatotoxicity in mice and unravel the mechanism of pyroptosis and ferroptosis in the process of liver injury, we treated mice with 5.0 μm polypropylene microplastics (MPs) at 0.1, 0.5 and 1 mg/mL for 4 weeks. Results revealed that MPs could damage liver structure and function with broken and reduced mitochondrial cristae, as well as increased levels of aspartate minotransferase (AST), alanine aminotransferase (ALT), AST/ALT, alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). Treatment with MPs resulted in pyroptosis as evidenced by increasing expressions of interleukin IL-1β, IL-18. Additionally, MPs were shown to induce the NOD-like receptor protein 3 (NLRP3) inflammasomes and apoptosis associated speck-like protein (ASC) containing a caspase recruitment domain activation in liver tissue, enabling activation of Caspase-1-dependent signaling pathway induced by inflammatory stimuli resulting from oxidative stress. In addition, the increase of malondialdehyde (MDA) and decrease of glutathione (GSH) and superoxide dismutase (SOD) in the liver indicated that MPs could induce oxidative damage. Moreover, MPs induced lipid peroxidation in the liver of mice could activate the expression of ferroptosis related proteins, including iron metabolism, such as transferrin receptor (TFRC) was active but ferritin heavy chain 1 (FTH1) was inhibited; amino acid metabolism, such as XCT system and glutathione peroxidase 4 (GPX4) were inhibited; lipid metabolism, such as acyl-CoA synthetase long-chain family member 4 (ACSL4) was inhibited. Collectively, these findings evidenced that pyroptosis and ferroptosis occurred in MPs-induced liver injury accompanied by intense oxidative stress and inflammation.

HMGB2 causes photoreceptor death via down-regulating Nrf2/HO-1 and up-regulating NF-κB/NLRP3 signaling pathways in light-induced retinal degeneration model

In the pathogenesis of retinal degenerative diseases, oxidative stress is a key driver leading to photoreceptor death and eventually vision loss. Currently, there are no effective therapies available to rescue photoreceptors in these diseases. High-mobility group box 2 (HMGB2), a pro-inflammatory factor and damage-associated molecular patterns (DAMPs), has been proven to mediate various inflammatory diseases, but its role in retinal degenerative diseases, especially in retinal inflammation and photoreceptor degeneration, still remains unknown. In this study, we assessed the localization and function of HMGB2 under oxidative stress and explored the underlying mechanisms in a mouse model of light-induced retinal damage (LIRD). The results showed that increased oxidative stress, the photoreceptors death, as well as the pyroptosis-related proteins were evidenced in mice retina after light exposure. HMGB2 protein was predominantly expressed in the outer nuclear layer (ONL), which was translocated to the cytoplasm and released after injury. The mechanistic effect of HMGB2 was studied in the 661w cell line treated with H₂O₂, showing that exogenous recombinant HMGB2 protein reduced the expressions of the antioxidant protein nuclear erythroid factor 2-related factor 2 (Nrf2) and its downstream target heme oxygenase-1 (HO-1), and induced NF-κB/NLRP3 signaling pathway. HMGB2 knockdown increased cell viability, up-regulated the expressions of Nrf2 and HO-1, down-regulated the expressions of pyroptosis-related proteins in H₂O₂-treated 661w cells; and also prevented photoreceptors loss and maintained ONL in mice model of LIRD. The present study proposed HMGB2 as a potential therapeutic target for treatment of retinal degenerative diseases.

Nrf2 protects against cerebral ischemia-reperfusion injury by suppressing programmed necrosis and inflammatory signaling pathways

Background

The NOD-like receptor family pyrin domain-containing 3 (NLRP3) -mediated neuroinflammation is linked to neuronal necroptosis in cerebral ischemia-reperfusion (I/R) injury, especially in cerebral ischemic penumbra. This study was designed to investigate the regulation of nuclear factor E2-related factor-2 (Nrf2) on NLRP3 inflammasome in necroptosis signal pathway induced by I/R injury.

Methods

We investigated the mechanisms of Nrf2-negative regulation in necroptosis signaling pathway by using middle cerebral artery occlusion (MCAO) with Q-VD-OPH injected intraperitoneally. The protein level of the NLRP3 inflammasome was detected by western blot with Nrf2 knockdown and overexpression. NLRP3 inflammasome activation was Reactive oxygen species (ROS) dependent, and the protein level was regulated when N-acetylcysteine (NAC) and adenosine triphosphate (ATP) were selected as tools for regulating ROS.

Results

We demonstrated the negative regulation of Nrf2 on NLRP3 inflammasome activation in Q-VD-OPH-induced necroptosis in cerebral artery I/R injury through Lentivirus-mediated RNA Interferenc, which mediated knockdown and overexpression of Nrf2. NLRP3 inflammasome activation was sensitive to both ATP-mediated ROS level increases and NAC-mediated ROS inhibition, suggesting that ROS is associated with the activation of NLRP3 inflammasome in necroptosis. In addition, Nrf2-induced NAD(P)H quinone dehydrogenase 1 (NQO1) was involved in the inhibition of NLRP3 inflammasome activation. These results suggest that Nrf2 regulates NQO1 to attenuate ROS, which negatively regulates NLRP3 inflammasome.

Conclusions

Nrf2/NQO1 was an inhibitor of ROS-induced NLRP3 inflammasome activation in Q-VD-OPH-induced necroptosis following cerebral I/R injury. Therefore, NLRP3 inflammasome could be a potential therapeutic target for cerebral ischemia.

Pyroptosis-Induced Inflammation and Tissue Damage

Programmed cell deaths are pathways involving cells playing an active role in their own destruction. Depending on the signaling system of the process, programmed cell death can be divided into two categories, pro-inflammatory and non-inflammatory. Pyroptosis is a pro-inflammatory form of programmed cell death. Upon cell death, a plethora of cytokines are released and trigger a cascade of responses from the neighboring cells. The pyroptosis process is a double-edged sword, could be both beneficial and detrimental in various inflammatory disorders and disease conditions. A physiological outcome of these responses is tissue damage, and sometimes death of the host. In this review, we focus on the inflammatory response triggered by pyroptosis, and resulting tissue damage in selected organs.

Biomimetic Metal-Organic Framework Nanoparticles for Synergistic Combining of SDT-Chemotherapy Induce Pyroptosis in Gastric Cancer

In recent years, sonodynamic therapy (SDT) has been widely developed for cancer research as a promising non-invasive therapeutic strategy. Here, we synthesized zeolitic imidazole frameworks-8 (ZIF-8) and utilized its properties to encapsulate hydrophobic Chlorin e6 (Ce6) and hydrophilic tirapazamine (TPZ) for a synergistic sonodynamic chemotherapy, which was also accompanied by the modification of cytomembrane of gastric cancer (GC) cells. Thus, we enabled the biomimetic property to achieve targeted delivery. Ce6-mediated SDT, in combination with ultrasound irradiation, could target the release of reactive oxygen species (ROS) to aggravate further hypoxia and activate TPZ. Combining these effects could induce the pyroptosis of GC cells and play the anti-tumor function, which could provide a potential therapeutic method for cancer therapy.

Dosage of Dual-Protein Nutrition Differentially Impacts the Formation of Atherosclerosis in ApoE-/- Mice

Atherosclerosis (AS) is recognized as the original cause of most cardiovascular and cerebrovascular diseases. The dual-protein (DP) nutrition that consists of soy protein and whey protein is reported to be associated with a reduction in AS; however, the relationship between DP and AS remains ambiguous. Therefore, this study aimed to verify the effect of DP on AS and explore the optimal DP intake to improve AS. ApoE^−/− mice were administrated with low- (LDP), middle- (MDP), and high-dose (HDP) DP. The MDP group exhibited significant improvements in AS. In terms of lipid metabolism, the levels of plasma total triglyceride and LDL-C and the mRNA expression levels of Cyp7a1 and PCSK9 were markedly tuned in the MDP group. In addition, the MDP treatment group had a substantially lower inflammatory response and better intestinal barrier function than LDP and HDP groups. The species richness demonstrated by the Chao1 index was distinctly increased in the MDP group, and the relative abundance of intestinal-permeability-protective microbes Blautia and Akkermansia was significantly elevated. In summary, an adequate intake of DP was able to counteract atherosclerosis development in ApoE^−/− mice, and this study provides a scientific theoretical basis for the application of DP in the food and pharmaceutical fields.