Cadmium induces NLRP3 inflammasome-dependent pyroptosis in vascular endothelial cells

The cascade of cadmium toxicity: from cellular damage to pyroptotic responses in fish Channa punctatus

Cadmium pollution is a major environmental issue threatening aquatic ecosystems and the health of aquatic organisms. Our study examines cadmium toxicity at different levels, highlighting pyroptotic cell death in the freshwater fish Channa punctatus (spotted snakehead). For this purpose, 90 well-acclimatized fish were categorized into three groups: one control and two treatment groups, i.e., T1 and T2, which were exposed to two sub-lethal concentrations of cadmium chloride (Cdcl2), i.e., 1.18 mg/L (one-tenth of 96-h lethal concentration [LC50]) and 2.36 mg/L (one-fifth of 96-h LC50), respectively, for a duration of 7, 14, and 21 days. Post-completion of experimental periods, various assessments were carried out. Reactive oxygen species levels significantly increased, indicating enhanced oxidative stress, along with elevated activities of superoxide dismutase and catalase (P < 0.05). In contrast, reduced glutathione levels decreased in a dose- and duration-dependent manner (P < 0.05). Additionally, lipid peroxidation increased markedly, and liver biomarkers, including serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, alkaline phosphatase, and lactate dehydrogenase, were significantly elevated (P < 0.05) in a time- and concentration-dependent pattern. Histopathological investigations of liver revealed pronounced deformities that were dose-dependent, with higher concentrations of cadmium causing more severe damage. Subsequently, prolonged cadmium exposure led to pyroptosis in the hepatocytes, characterized by the elevated expression of nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3; caspase-1, interleukin-1β, interleukin-18; apoptosis-associated speck-like protein containing a CARD; and Gasdermin E. These results highlighted the significant impact of cadmium on C. punctatus, underscoring its importance as a key bio-indicator for aquatic pollution. The study emphasizes the urgent need to monitor and regulate cadmium levels to protect aquatic life and maintain ecological balance.

Association between urinary metallothionein concentration and causes of death among cadmium-exposed residents in Japan: a 35-year follow-up study

BACKGROUND

As research progresses, there is a growing body of evidence indicating that urinary metallothionein (MT) levels may be elevated in individuals exposed to cadmium (Cd). This study aimed to investigate the potential association between urinary MT levels and causes of mortality among residents of the Kakehashi River Basin who have been exposed to Cd.

METHOD

The study involved a total of 1,398 men and 1,731 women were conducted between 1981 and 1982, with follow-up until November 2016. The study employed the Cox proportional-hazards model to examine the association between higher urinary MT concentrations and the risk of all-cause or cause-specific mortality within the population. Furthermore, the Fine and Gray competing risks regression model was used to evaluate the links between specific causes of death.

RESULTS

The findings revealed that elevated urinary MT concentrations were linked to increased all-cause mortality and higher mortality rates from renal and urinary tract diseases across all participants. Specifically, in men, higher urinary MT levels were associated with elevated all-cause mortality, while in women, increased concentrations were linked to higher mortality from endocrine, nutritional, and metabolic diseases, as well as cardiovascular diseases. Even after adjusting for competing risks, higher urinary MT concentrations were associated with tumor-related mortality in men and continued to be associated with cardiovascular disease mortality in women.

CONCLUSIONS

In conclusion, the results suggest that women may face a greater risk of adverse health effects due to prolonged exposure to Cd. Urinary MT levels could potentially serve as a biomarker for mortality from these diseases in populations chronically exposed to Cd.

Mechanism of Ligusticum wallichii-Borneol in the Treatment of Cerebral Ischemic Stroke in Rats Based On Network Pharmacology, Molecular Docking, and Experimental Verification

The pharmacodynamics, molecular biology, network pharmacology, and molecular docking mechanisms of the Ligusticum wallichii and borneol medication pair (CXBP) were investigated for ischemic stroke treatment. Effective chemical components and targets of CXBP were identified using TCMSP, ETCM, and SymMap databases, whereas ischemic stroke targets were sourced from OMIM, GeneCards, TTD, PubMed, Web of Science, CNKI, Wanfang Data, and VIP databases. Protein-protein interaction (PPI) networks were generated using the STRING database, and GO and KEGG enrichment analyses were conducted using Metascape. A "disease-pathway-target-component-drug" network was created in Cytoscape, and molecular docking was confirmed with PyMOL and AutoDock tools. Rat models of MCAO were established to evaluate neurological scores, triphenyltetrazolium chloride (TTC) staining, and Nissl staining. Key components were validated through enzyme-linked immunosorbent assay (ELISA), real-time polymerase chain reaction (PCR), and immunohistochemistry. Thirty-three active ingredients and 419 potential targets for CXBP, with key compounds including Z-6,8',7,3'-diligustilide, cedrene, (+)-alpha-funebrene, POL, dipterocarpol, oleanolic acid, 1-acetyl-beta-carboline, and erythrodiol. Critical targets included ESR1, PRKCA, and PTPN6. KEGG pathway analysis revealed 179 signaling pathways, primarily neuroactive ligand-receptor interactions, whereas GO enrichment analysis identified 2911 biological processes, 398 molecular activities, and 203 cellular components. The neurological function scores and TTC staining of the infarcted brain regions were significantly improved following CXBP intervention compared to the MCAO group. These findings were supported by Nissl staining, which demonstrated better preserved cellular morphology and a significantly higher number of Nissl vesicles in the CXBP group. ELISA analysis revealed substantial modulation in gene expression: levels of PRKCA, PTPN6, ESR1, and TNF-α changed significantly, whereas IL-1β, IL-6, and TNF-α were notably downregulated compared to the MCAO group. PCR results corroborated these findings, showing a significant decrease in PRKCA expression and marked downregulation of IL-1β, IL-6, and TNF-α, whereas ESR1 and PTPN6 levels increased significantly. Immunohistochemical analysis further confirmed these results, with the CXBP and nimodipine groups exhibiting higher ESR1 and PTPN6 expression and lower PRKCA expression compared to the MCAO group. To improve cerebral ischemia and reperfusion injury, CXBP improves ischemic stroke outcomes through key active ingredients (e.g., Z-6,8',7,3'-diligustilide, cedrene, and oleanolic acid) and targets ESR1, PRKCA, and PTPN6, modulating multiple signaling pathways to alleviate cerebral ischemia-reperfusion injury.

The METTL3/m6A Reader Protein YTHDF1 Regulates Endothelial Cell Pyroptosis by Enhancing NLRP3 Expression to Affect Soft Tissue Injury

Background

Pyroptosis is inflammation-associated programmed cell death triggered by activation of the NOD-like receptor protein 3 (NLRP3) inflammasome, which plays a crucial role in acute soft tissue injury (ASTI). This study aimed to explore whether methyltransferase-like 3 (METTL3) can regulate NLRP3 expression through N6-methyladenosine (m6A) modification to mediate endothelial cell pyroptosis and thus affect soft tissue injury.

Methods

An experimental ASTI rat model was created by inducing muscle injury through striking the rat muscle. In vitro, an ASTI cell model was established using human umbilical vein endothelial cells (HUVECs) stimulated with lipopolysaccharide (LPS) and ATP. The severity of ASTI in rats was evaluated using H&E staining. To assess protein levels, Western blot and Immunohistochemistry (IHC) analyses were performed, focusing on METTL3, pyroptosis-associated proteins, and m6A reader proteins. Immunofluorescence (IF) assay was conducted to examine the expression of NLRP3 and CD31. The levels of inflammatory cytokines were measured using an ELISA assay, while flow cytometry was used to detect levels of ROS and cellular pyroptosis. The m6A levels in cells were analyzed by RNA m6A colorimetry. The interactions between METTL3 and NLRP3, and YTHDF1 and NLRP3 were analyzed using RIP and RNA pull-down assays, respectively.

Results

METTL3 and YTHDF1 were significantly upregulated in ASTI rats and LPS-ATP-induced HUVECs. Knockdown of METTL3 ameliorated ASTI and inhibited cellular pyroptosis. Knockdown of METTL3 reduced the levels of total m6A and NLRP3 m6A in HUVECs and suppressed NLRP3 expression. Meanwhile, knockdown of YTHDF1 decreased NLRP3 protein expression without affecting NLRP3 mRNA levels. In addition, overexpression of NLRP3 was able to reverse the effect of METTL3 on LPS-ATP-induced endothelial cell pyroptosis.

Conclusion

The METTL3/m6A reader protein YTHDF1 regulates endothelial cell pyroptosis by enhancing NLRP3 expression to affect soft tissue injury.

Cadmium exposure triggers alveolar epithelial cell pyroptosis by inducing mitochondrial oxidative stress and activating the cGAS-STING pathway

BACKGROUND

Cadmium is a ubiquitous toxic metal and environmental pollutant. More and more studies have shown that cadmium exposure can damage lung function. Alveolar epithelial cells (AECs) are structural cells that maintain the stability of lung function. The injury of AECs is an essential determinant of many lung diseases. In the lung, cadmium accumulation can cause damage to AECs. However, the specific mechanism is still unclear. This study aimed to explore the key mechanism underlying the injury of AECs caused by cadmium exposure.

METHODS

The main modes of death of AECs induced by cadmium exposure were evaluated in vivo and in vitro. Transcriptomic changes of AECs induced by cadmium exposure were analyzed using RNA-sequence. Mitochondrial ROS scavengers (mitoQ), voltage-dependent anion channel 1 (VDAC1) oligomer inhibitor (VBIT4), and cyclic GMP-AMP synthase (cGAS) inhibitor (RU.521) were used to assess whether cadmium exposure triggered pyroptosis of AECs by inducing mitochondrial stress to activate the cGAS-STING-NLRP3 axis.

RESULTS

In this study, the expression of pyroptosis-related proteins was significantly up-regulated in the cadmium-exposed AECs, while the expression of apoptosis, necroptosis, and ferroptosis-related proteins had no significant up-regulated. The pan-caspase inhibitor ZVAD-FMK significantly reduced cell death. Thus, our research indicates that pyroptosis is the primary type of AEC death exported to cadmium. Mechanistically, RNA-seq and Western Blot results showed that cadmium exposure activated the cGAS-STING pathway in AECs and promoted pyroptosis by activating the NLRP3 inflammasome. Further investigation of the mechanism found that cadmium exposure caused mitochondrial oxidative stress, which led to mtDNA leakage into the cytoplasm and activated the cGAS-STING pathway. In addition, inhibition of the cGAS-STING pathway significantly alleviated lung injury induced by cadmium exposure in mice.

CONCLUSION

Our study confirmed that pyroptosis of AECs was a vital mechanism of lung injury after cadmium exposure in a cGAS-STING-dependent manner, which may provide a new target for the treatment of lung diseases induced by cadmium exposure.

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

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

Differential effect of lead and cadmium on mitochondrial function and NLRP3 inflammasome activation in human trophoblast

Heavy metals disrupt mitochondrial function and activate the NOD-like receptor pyrin-containing 3 (NLRP3) inflammasome. We investigated the effect of lead (Pb)/cadmium (Cd) on mitochondrial function and NLRP3 inflammasome activation in human trophoblast under normoxic, hypoxic and pro-inflammatory conditions. JEG-3, BeWo and HTR-8/SVneo cells were exposed to Pb or Cd for 24 h in the absence or presence of hypoxia or pro-inflammatory lipopolysaccharide (LPS) or poly(I:C). Then, we evaluated cell viability, apoptosis, mitochondrial DNA copy number (mtDNAcn), mitochondrial membrane potential (ΔΨ), NLRP3 inflammasome proteins and interleukin (IL)-1β secretion. Although our data showed that Pb, Cd, hypoxia, poly(I:C) and LPS decreased mtDNAcn in the three cell lines, the effects of these treatments on other biomarkers were different in the different cell lines. We found that hypoxia decreased ΔΨ and promoted apoptosis in JEG-3 cells, increased ΔΨ and prevented apoptosis in BeWo cells, and did not change ΔΨ and apoptosis in HTR-8/SVneo cells. Moreover, Pb under hypoxic conditions reduced ΔΨ and promoted apoptosis of BeWo cells. Exposure of BeWo and HTR-8/SVneo cells to hypoxia, Pb or Cd alone upregulated the expression of NLRP3 and pro-caspase 1 but did not activate the NLRP3 inflammasome since cleaved-caspase 1 and IL-1β were not increased. To conclude, Pb and Cd affected trophoblast mitochondrial function and NLRP3 proteins in trophoblast cell lines, but in a cell line-specific way. KEY POINTS: The objective of this work was an understanding of the effect of lead (Pb) and cadmium (Cd) on mitochondrial function and NLRP3 inflammasome activation in human trophoblast cell lines under normoxic, hypoxic and pro-inflammatory conditions. Apoptosis of JEG-3 cells was increased by hypoxia, while in BeWo cells, apoptosis was decreased by hypoxia, and in HTR-8/SVneo, apoptosis was not affected by hypoxic treatment. Exposure to either Pb or Cd decreased mtDNAcn in three human placental trophoblast cell lines. However, Pb under hypoxia induced a decrease of ΔΨ and promoted apoptosis of BeWo cells, but Cd did not induce a reduction in ΔΨ in the three trophoblast cell lines under any conditions. Exposure to hypoxia, Pb or Cd increased NLRP3 and pro-caspase 1 in BeWo and HTR-8/SVneo cells. Our findings highlight that Pb and Cd affected trophoblast mitochondrial function and NLRP3 proteins in trophoblast cell lines but in a cell line-specific way.

Phytochemistry of Genus Buxus and Pharmacology of Cyclovirobuxine D

BACKGROUND

Genus Buxus plants, commonly known as "boxwood", are widely distributed in China. The stems, branches, and leaves of the plant are traditionally used for rheumatism, toothache, chest pain, abdominal gas, and other diseases. However, an overview of the genus Buxus remains to be provided.

PURPOSE

To provide a scientific basis for the appropriate use and further research the recent advancements in the traditional usage, phytochemistry, and, pharmacology of Buxus.

STUDY DESIGN

Chemical composition and pharmacological correlation studies through a literature review.

METHODS

Between 1970 and 2023, the available data concerning Buxus was compiled from online scientific sources, such as Sci-Finder, PubMed, CNKI, Google Scholar, and the Chinese Pharmacopoeia. Plant names were verified from "The Plant List" (http://www.theplantlist.org/).

RESULTS

To date, 266 structurally diverse chemicals have been extracted and identified from the genus Buxus. Alkaloids constitute one of its primary bioactive phytochemicals. A summary of the channels of action of Cyclovirobuxine D on the cytotoxicity of a variety of cancers has been provided.

CONCLUSION

Numerous findings from contemporary phytochemical and pharmacological studies support the traditional use, facilitating its application. Further research is necessary to address various shortcomings, including the identification of the active ingredients and quality control of the genus Buxus.

Oxidative Stress-Mediated Programmed Cell Death: a Potential Therapy Target for Atherosclerosis

Nowadays, as a type of orderly and active death determined by genes, programmed cell death (PCD), including apoptosis, pyroptosis, ferroptosis, and necroptosis, has attracted much attention owing to its participation in numerous chronic cardiovascular diseases, especially atherosclerosis (AS), a canonical chronic inflammatory disease featured by lipid metabolism disturbance. Abundant researches have reported that PCD under distinct internal conditions fulfills different roles of atherosclerotic pathological processes, including lipid core expansion, leukocyte adhesion, and infiltration. Noteworthy, emerging evidence recently has also suggested that oxidative stress (OS), an imbalance of antioxidants and oxygen free radicals, has the potential to mediate PCD occurrence via multiple ways, including oxidization and deubiquitination. Interestingly, more recently, several studies have proposed that the mediating mechanisms could effect on the atherosclerotic initiation and progression significantly from variable aspects, so it is of great clinical importance to clarify how OS-mediated PCD and AS interact. Herein, with the aim of summarizing potential and sufficient atherosclerotic therapy targets, we seek to provide extensive analysis of the specific regulatory mechanisms of PCD mediated by OS and their multifaceted effects on the entire pathological atherosclerotic progression.

Coenzyme Q10 mitigates cadmium cardiotoxicity by downregulating NF-κB/NLRP3 inflammasome axis and attenuating oxidative stress in mice

Coenzyme Q10 (CoQ10) occurs naturally in the body and possesses antioxidant and cardioprotective effects. Cardiotoxicity has emerged as a serious effect of the exposure to cadmium (Cd). This study investigated the curative potential of CoQ10 on Cd cardiotoxicity in mice, emphasizing the involvement of oxidative stress (OS) and NF-κB/NLRP3 inflammasome axis. Mice received a single intraperitoneal dose of CdCl2 (6.5 mg/kg) and a week after, CoQ10 (100 mg/kg) was supplemented daily for 14 days. Mice that received Cd exhibited cardiac injury manifested by the elevated circulating cardiac troponin T (cTnT), CK-MB, LDH and AST. The histopathological and ultrastructural investigations supported the biochemical findings of cardiotoxicity in Cd-exposed mice. Cd administration increased cardiac MDA, NO and 8-oxodG while suppressed GSH and antioxidant enzymes. CoQ10 decreased serum CK-MB, LDH, AST and cTnT, ameliorated histopathological and ultrastructural changes in the heart of mice, decreased cardiac MDA, NO, and 8-OHdG and improved antioxidants. CoQ10 downregulated NF-κB p65, NLRP3 inflammasome, IL-1β, MCP-1, JNK1, and TGF-β in the heart of Cd-administered mice. Moreover, in silico molecular docking revealed the binding potential between CoQ10 and NF-κB, ASC1 PYD domain, NLRP3 PYD domain, MCP-1, and JNK. In conclusion, CoQ10 ameliorated Cd cardiotoxicity by preventing OS and inflammation and modulating NF-κB/NLRP3 inflammasome axis in mice. Therefore, CoQ10 exhibits potent therapeutic benefits in safeguarding cardiac tissue from the harmful consequences of exposure to Cd.

CCL11 released by GSDMD-mediated macrophage pyroptosis regulates angiogenesis after hindlimb ischemia

Peripheral vascular disease (PVD) is an emerging public health burden with a high rate of disability and mortality. Gasdermin D (GSDMD) has been reported to exert pyroptosis and play a critical role in the pathophysiology of many cardiovascular diseases. We ought to determine the role of GSDMD in the regulation of perfusion recovery after hindlimb ischemia (HLI). Our study revealed that GSDMD-mediated pyroptosis occurred in HLI. GSDMD deletion aggravated perfusion recovery and angiogenesis in vitro and in vivo. However, how GSDMD regulates angiogenesis after ischemic injury remains unclear. We then found that GSDMD-mediated pyroptosis exerted the angiogenic capacity in macrophages rather than endothelial cells after HLI. GSDMD deletion led to a lower level of CCL11 in mice serum. GSDMD knockdown in macrophages downregulated the expression and decreased the releasing level of CCL11. Furthermore, recombinant CCL11 improved endothelial functions and angiogenesis, which was attenuated by CCL11 antibody. Taken together, these results demonstrate that GSDMD promotes angiogenesis by releasing CCL11, thereby improving blood flow perfusion recovery after hindlimb ischemic injury. Therefore, CCL11 may be a novel target for prevention and treatment of vascular ischemic diseases.

The Protective Effects of Ganoderma lucidum Active Peptide GLP4 on Lung Injury Induced by Cadmium Poisoning in Mice

Ganoderma triterpenes and spore powder have shown promising results in mitigating cadmium-induced renal and hepatic injuries. Ganoderma lucidum active peptide GLP4 is a natural protein with dual antioxidant activities derived from the mycelium of Ganoderma lucidum. However, its efficacy in alleviating cadmium-induced lung injury remains unexplored. This study aims to investigate the protective effects of GLP4 against cadmium-induced lung injury in mice. Mice were exposed to cadmium chloride via nebulization to induce lung injury. The protective effect of GLP4 was assessed by measuring the total cell count in BALF, levels of inflammatory cytokines, and the expression of NLRP3 in lung tissues a through histopathological examination of lung tissue changes. The results showed that GLP4 significantly mitigated histopathological damage in lung tissues, decreased the secretion of inflammatory cytokines, and reduced the expression of NLRP3, which was elevated in cadmium-exposed mice. In vitro studies further revealed that GLP4 inhibited the cadmium-induced activation of the NLRP3 inflammasome. Notably, acute cadmium exposure by the respiratory tract did not affect the liver and kidneys of the mice. The findings suggest that GLP4 reduces cadmium-induced lung injury in mice by inhibiting the activation of the NLRP3 inflammasome, which provides a theoretical foundation for using Ganoderma lucidum as a preventive and therapeutic agent against cadmium poisoning.

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 β-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-1β 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.

Prognostic and clinicopathological significance of FOXD1 in various cancers: a meta and bioinformation analysis

Aim: To examine both predictive and clinicopathological importance underlying FOXD1 in malignant tumors, our study adopts meta-analysis. Methods: We searched from PubMed, Embase, WOS, Wanfang and CNKI. Stata SE15.1 was used to calculate the risk ratio (HR) as well as relative risk (RR) with 95% of overall CIs to assess FOXD1 and overall survival rate (OS), disease-free survival rate as well as clinicopathological parameters. Results: 3808 individuals throughout 17 trials showed high FOXD1 expression was linked to disadvantaged OS (p < 0.001) and disease-free survival (p < 0.001) and higher TNM stage (p < 0.001). Conclusion: Elevated FOXD1 had worse predictions and clinicopathological parameters in most cancers. The GEPIA database findings also support our results.

Maternal exposure to ZIF-8 derails placental function by inducing trophoblast pyroptosis through neutrophils activation in mice

Adverse environmental factors during maternal gestation pose a threat to pregnancy. Environmental factors, particularly nanoparticles, can impact pregnancy by causing damage to the placenta. Compared to early gestation, foetuses in late gestation are more robustly developed and at lower risk of adverse effects from environmental factors. Delivery systems for targeted therapy during pregnancy is predominantly focused on their application in late gestation. Zeolitic imidazolate framework-8 (ZIF-8) holds great potential for targeted drug therapy. To evaluate the value of ZIF-8 in targeted treatment of disorders associated with late gestation, it is crucial to investigate the biological effects of ZIF-8 exposure during late gestation. Here, a mouse model exposed to ZIF-8 particles at different doses (5, 10, and 15 mg/kg) during late gestation was constructed. We found that ZIF-8 particles were deposited in the uterus of pregnant mice. ZIF-8 could trigger placental neutrophil aggregation and induce inflammation, which led to trophoblast pyroptosis and impair placental function, adversely affecting the foetus. Neutrophil depletion alleviated placental and foetal damage induced by ZIF-8. This study provides a novel mechanistic view of the reproductive toxicity induced by ZIF-8 and may offer clues to reduce the latent harm of adverse environmental factors to pregnancy.

Effects of intratesticular injection of hypertonic mannitol and saline on the quality of donkey sperm, indicators of oxidative stress and testicular tissue pathology

OBJECTIVES

The aim of the present study was to examine donkey sperm quality after intratesticular injection of hypertonic mannitol (HM) and saline (HS).

METHODS

Randomly assigned to five treatment groups were 15 adult male donkeys: (1) Control group (no treatment), (2) Surgery group (surgical castration for testosterone control), (3) NS group (normal saline intratesticular injection), (4) HS group (hypertonic saline), and (5) HM group. We injected 20 mL per testicle. We took 5 mL blood from all donkeys before injection. Castration was performed under general anesthesia 60 days later. Samples included blood and testicular tissue. Total motility (TM), progressive motility (PM), movementy features, DNA damage, morphology, viability, and plasma membrane functionality were evaluated. Hormone analyses, histomorphometric studies and oxidative stress indices including total antioxidant capacity (TAC), glutathione peroxidase (GPx), glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), and NADP+/NADPH were evaluated. Apoptosis, pyroptosis-related Bax, Caspase-1, GSDMD, and Bcl-2 expression were also assessed.

RESULTS

In HS and HM groups, testosterone, epididymal sperm count, motility, viability, and plasma membrane functionality dropped while sperm DNA damage increased. HS and HM groups had significantly lower histomorphometric parameters, TAC, GPx, SOD, GSH, and Bcl-2 gene expression. MDA, NADP+/NADPH, Bax, Caspase-1, and GSDMD gene expression were substantially higher in the HS and HM groups than in the control group.

CONCLUSIONS

Toxic effects of hypertonic saline and mannitol on reproductive parameters were seen following, hence, they might be considered as a good chemical sterilizing treatment in donkeys.

Cadmium exposure induces pyroptosis of TM4 cells through oxidative stress damage and inflammasome activation

Cadmium (Cd) is a harmful metal that seriously affects the male reproductive system, but the mechanism of how Cd exposure damages Sertoli cells is not fully understood. This study used TM4 cells to explore the mechanism of Cd damage to Sertoli cells. We found that Cd was concentration- and time-dependent on TM4 cell viability. Cd exposure increased intracellular reactive oxygen species (ROS) levels, lactate dehydrogenase (LDH), and Interleukin-1β (IL-1β) release in TM4 cells, decreased mitochondrial function, and increased pyroptosis. N-acetylcysteine (NAC), MCC950 and BAY 11-7082 (BAY) alleviate the release of IL-1β and LDH induced by Cd. NAC reduced Cd induced increases in ROS, NLRP3, Caspase-1, Heme oxygenase-1(HO-1), superoxide dismutase (SOD2), and increased mitochondrial function. The activation of GSDMD is the main causes of pyroptosis, and NAC significantly inhibit its activation and formation. Our results suggest that Cd exposure induces a toxic mechanism of GSDMD-mediated pyroptosis in TM4 cells by increasing ROS levels and activating the inflammasome.

NLRP3 inflammasome-mediated pyroptosis involvement in cadmium exposure-induced cognitive deficits via the Sirt3-mtROS axis

Cadmium (Cd), a toxic heavy metal, exerts deleterious effects on neuronal survival and cognitive function. NOD-like receptor 3 (NLRP3) inflammasome-dependent pyroptosis has been linked to Cd-induced cytotoxicity. The current research intended to elucidate the role of NLRP3 inflammasome-mediated pyroptosis in Cd-evoked neuronal death and cognitive impairments and the underlying mechanisms. Exposure to 1 mg/kg Cd for 8 weeks led to hippocampal-dependent cognitive deficits and neural/synaptic damage in mice. NLRP3 inflammasome-related protein expression (NLRP3, ASC, and caspase1 p20) and neuronal pyroptosis were significantly upregulated in Cd-treated hippocampi and SH-SY5Y cells. Moreover, pretreatment with the NLRP3 inhibitor MCC950 mitigated Cd-elicited NLRP3 inflammasome activation and subsequent neuronal pyroptosis in SH-SY5Y cells. Furthermore, exposure to Cd downregulated Sirt3 expression, suppressed SOD2 activity by hyperacetylation, and enhanced mtROS accumulation in vivo and in vitro. Notably, Cd-induced NLRP3 inflammasome-dependent neuronal pyroptosis was attenuated by a mtROS scavenger or Sirt3 overexpression in SH-SY5Y cells. In addition, Cd failed to further suppress SOD activity and activate NLRP3 inflammasome-dependent neuronal pyroptosis in Sirt3 shRNA-treated SH-SY5Y cells. Collectively, our findings indicate that Cd exposure induces neuronal injury and cognitive deficits by activating NLRP3 inflammasome-dependent neuronal pyroptosis and that activation of the NLRP3 inflammasome is partially mediated by the Sirt3-mtROS axis.

Cadmium-induced pyroptosis is mediated by PERK/TXNIP/NLRP3 signaling in SH-SY5Y cells

Cadmium (Cd) is a hypertoxic heavy metal that may be exposed to environmental pollutants by humans and animals. It can lead to cognitive disfunction, and is linked to neurodegenerative diseases. Cadmium reportedly can induce endoplasmic reticulum (ER) stress, but few studies have concentrated on it in nerve cells, and the connection between ER stress and neuroinflammation. In this study, in vitro experiments on SH-SY5Y neuroblastoma cells were carried out. We aimed at exploring whether Cd attributed to the cell pyroptosis and the role of PERK in promoting this form of cell damage which can induce strong inflammatory responses. Our results demonstrated that CdCl2 treatment induced excess reactive oxygen species (ROS) production, caused significant modifications in the expression of PERK and increased TXNIP, NLRP3, IL-1β, IL-18, and caspase1 in SH-SY5Y cells. In addition, scavenging ROS with N-acetylcysteine or inhibiting the expression of PERK by using GSK2606414, rescued the SH-SY5Y cells from cadmium-induced pyroptosis. In conclusion, the results suggest that Cd induces pyroptotic death of SH-SY5Y cells through ER stress, and this may be the potential mechanism of Cd incurring neurological diseases.

Recent insights into autophagy and metals/nanoparticles exposure

Some anthropogenic pollutants, such as heavy metals and nanoparticles (NPs), are widely distributed and a major threat to environmental safety and public health. In particular, lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), and mercury (Hg) have systemic toxicity even at extremely low concentrations, so they are listed as priority metals in relation to their significant public health burden. Aluminum (Al) is also toxic to multiple organs and is linked to Alzheimer's disease. As the utilization of many metal nanoparticles (MNPs) gradually gain traction in industrial and medical applications, they are increasingly being investigated to address potential toxicity by impairing certain biological barriers. The dominant toxic mechanism of these metals and MNPs is the induction of oxidative stress, which subsequently triggers lipid peroxidation, protein modification, and DNA damage. Notably, a growing body of research has revealed the linkage between dysregulated autophagy and some diseases, including neurodegenerative diseases and cancers. Among them, some metals or metal mixtures can act as environmental stimuli and disturb basal autophagic activity, which has an underlying adverse health effect. Some studies also revealed that specific autophagy inhibitors or activators could modify the abnormal autophagic flux attributed to continuous exposure to metals. In this review, we have gathered recent data about the contribution of the autophagy/mitophagy mediated toxic effects and focused on the involvement of some key regulatory factors of autophagic signaling during exposure to selected metals, metal mixtures, as well as MNPs in the real world. Besides this, we summarized the potential significance of interactions between autophagy and excessive reactive oxygen species (ROS)-mediated oxidative damage in the regulation of cell survival response to metals/NPs. A critical view is given on the application of autophagy activators/inhibitors to modulate the systematic toxicity of various metals/MNPs.

Tl(I) and Tl(III) induce reticulum stress in MDCK cells

The effects of the exposure of proliferating MDCK cells to thallium [Tl(I) or Tl(III)] on cell viability and proliferation were investigated. Although Tl stopped cell proliferation, the viability was >95%. After 3h, two autophagy markers (SQSTM-1 expression and LC3β localization) were altered, and at 48h increased expression of SQSTM-1 (60%) and beclin-1 (50-100%) were found. At 24h, the expression of endoplasmic reticulum (ER) stress markers ATF-6 and IRE-1 were increased in 100% and 150%, respectively, accompanied by XBP-1 splicing and nuclear translocation. At 48h, major ultrastructure abnormalities were found, including ER enlargement and cytoplasmic vacuolation which was not prevented by protein synthesis inhibition. Increased PHB (85% and 40% for Tl(I) and Tl(III), respectively) and decreased β-tubulin (45%) expression were found which may be related to the promotion of paraptosis. In summary, Tl(I) and Tl(III) promoted ER stress and probably paraptosis in MDCK cells, impairing their proliferation.

Tanshinone IIA mediates protection from diabetes kidney disease by inhibiting oxidative stress induced pyroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza is widely used traditional Chinese medicine in the treatment of diabetes kidney disease (DKD). Tanshinone IIA (Tan IIA) are one of the main components of the root of red-rooted Salvia miltiorrhiza Bunge. However, whether tanshinones delay the progression of DKD and the underlying mechanisms are unknown.

AIM OF THE STUDY

Clarify the mechanisms underlying the occurrence and progression of DKDs from a novel viewpoint and confirm the function and mechanism of Tan IIA.

MATERIALS AND METHODS

We experimented with models of DKD (db/db mice) and cultured human renal glomerular endothelial cells (HRGECs). We measured the biochemical indicators of mouse blood and urine to confirmed that Tan IIA exerted protective effects on the kidneys of db/db mice. Renal histopathology and immunohistochemical staining were used to determine the role of Tan IIA. High glucose-induced HRGECs pyroptosis based on the results of Western blot, CCK-8 cell viability test, calcein/PI staining, ROS/superoxide anion generation and transmission electron microscope. We also confirmed that Tan IIA alleviated HRGEC pyroptosis through the same methods. The relationships between oxidative induction and regulation of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation were investigated using Western blot following the application of an NLRP3 inhibitor and oxidative stress inhibitor.

RESULTS

Tan IIA alleviated kidney injury and improved the levels of urine, blood indicators, the expression of NLRP3 and thioredoxin-interacting protein (Txnip) in db/db mice kidney. In vitro, high glucose inhibited HRGECs viability, increased ROS generation, enhanced the proportion of propidium iodide-stained cells. In addition, we discovered the expression of GSDMD-NT, NLRP3, cleaved IL-1β, cleaved caspase-1, and Txnip increased, but the expression of Trx1 decreased after treated by high glucose. These changes were partially ameliorated by Tan IIA.

CONCLUSION

Hyperglycemia could induce pyroptosis in renal glomerular endothelial cells. However, Tan IIA could delay the progression of DKD by inhibiting pyroptosis by regulating the Txnip/NLRP3 inflammasome.

Pyroptosis-triggered pathogenesis: New insights on antiphospholipid syndrome

APS (antiphospholipid syndrome) is a systematic autoimmune disease presenting with the high levels of aPLs (antiphospholipid antibodies). These autoantibodies are involved in various clinical manifestations, mainly including arterial or venous thrombosis formation, proinflammatory response, and recurrent pregnant loss. Pyroptosis is a form of lytic programmed cell death, and it aggravates autoimmune diseases progression via activating NOD-like receptors, especially the NLRP3 inflammasome and its downstream inflammatory factors IL (interleukin)-1β and IL-18. However, the underlying mechanisms of pyroptosis-induced APS progression remain to be elucidated. ECs (endothelial cells), monocytes, platelets, trophoblasts, and neutrophils are prominent participants in APS development. Of significance, pyroptosis of APS-related cells leads to the excessive release of proinflammatory and prothrombotic factors, which are the primary contributors to APOs (adverse pregnancy outcomes), thrombosis formation, and autoimmune dysfunction in APS. Furthermore, pyroptosis-associated medicines have made encouraging advancements in attenuating inflammation and thrombosis. Given the potential of pyroptosis in regulating APS development, this review would systematically expound the molecular mechanisms of pyroptosis, and elaborate the role of pyroptosis-mediated cellular effects in APS progression. Lastly, the prospective therapeutic approaches for APS would be proposed based on the regulation of pyroptosis.

GPX4 utilization by selenium is required to alleviate cadmium-induced ferroptosis and pyroptosis in sheep kidney

Cadmium (Cd), a persistent and harmful heavy metal in the environment, can accumulate in the kidneys and cause nephrotoxicity. Selenium (Se) is a beneficial natural element that alleviates the toxicity of Cd. To ascertain the relationship between the protective mechanism of Se against Cd nephrotoxicity and ferroptosis and pyroptosis, we randomly divided 48 sheep into four groups and treated them with Cd chloride and/or sodium selenite for 50 days. The data confirmed that Cd apparently resulted in impaired kidney histology and function, depletion of GSH and nicotinamide adenine dinucleotide phosphate contents and CAT and SOD activities, elevation of MDA level, as well as the reduction in selenoprotein mRNA (GPX1, GPX4, TXNRD1, SELP) levels and GPX4 protein level and immunofluorescence intensity. Meanwhile, Cd induced ferroptosis by causing iron overload, up-regulating PTGS2, NCOA4, TFR1, and LC3B mRNA levels and PTGS2 and LC3B-II/LC3B-I protein levels, reducing SLC7A11 and FTH1 mRNA and protein levels, and enhancing the immunofluorescence co-localization of FTH1/LC3B. Moreover, it was also found that Cd triggered pyroptosis, which was evidenced by the increase of NLRP3 immunohistochemical positive signal, GSDMD-N immunofluorescence intensity, IL-1β and IL-18 release and the levels of pyroptosis-related mRNA (NLRP3, ASC, Caspase-1, GSDMD, IL-1β and IL-18) and proteins (NLRP3, Caspase-1p20, GSDMD-N, IL-1β and IL-18). Notably, Se increased the expression level of GPX4 and the transcription factors TFAP2c and SP1, and ameliorated Cd-induced changes in aforementioned factors. In conclusion, GPX4 utilization by Se might be required to alleviate Cd-induced ferroptosis and pyroptosis in sheep kidney.

Pollutant-induced pyroptosis in humans and other animals

Pyroptosis is a form of lytic cell death with pro-inflammatory characteristics, induced upon the activation of certain inflammatory caspases by inflammasome complexes such as NLRP3 inflammasome. Gasdermin proteins as the mediators of pyroptosis form cell membrane pores upon activation, which release certain cellular contents into the extracellular space including inflammatory cytokines such as IL-1β and IL-18, and also damage the integrity of the cell membrane. Gasdermins have been implicated in autoimmune and inflammatory diseases, infectious diseases, deafness and cancer. Mostly in the last 2 years, diverse pollutant types including particulate matter, cadmium and polystyrene microplastics were reported to induce pyroptotic cell death in diverse tissues from mammals to birds. In the present study, we review our current understanding of pollutant-induced pyroptosis as well as current knowledge of upstream events leading to pyroptotic cell death upon exposure to pollutants.

MCC950 Regulates Stem Cells Destiny Through Modulating SIRT3-NLRP3 Inflammasome Dynamics During Oxygen Glucose Deprivation

Ischemic stroke is the major cause of death and morbidity worldwide. Stem cell treatment is at the forefront of ischemic therapeutic interventions. However, the fate of these cells following transplantation is mostly unknown. The current study examines the influence of oxidative and inflammatory pathological events associated with experimental ischemic stroke (oxygen glucose deprivation (OGD)) on the stem cell population (human Dental Pulp Stem Cells, and human Mesenchymal Stem Cells) through the involvement of the NLRP3 inflammasome. We explored the destiny of the above-mentioned stem cells in the stressed micro (-environment) and the ability of MCC950 to reverse the magnitudes. An enhanced expression of NLRP3, ASC, cleaved caspase1, active IL-1β and active IL-18 in OGD-treated DPSC and MSC was observed. The MCC950 significantly reduced NLRP3 inflammasome activation in the aforementioned cells. Further, in OGD groups, oxidative stress markers were shown to be alleviated in the stem cells under stress, which was effectively relieved by MCC950 supplementation. Interestingly, whereas OGD increased NLRP3 expression, it decreased SIRT3 levels, implying that these two processes are intertwined. In brief, we discovered that MCC950 inhibits NLRP3-mediated inflammation by inhibiting the NLRP3 inflammasome and increasing SIRT3. To conclude, according to our findings, inhibiting NLRP3 activation while enhancing SIRT3 levels with MCC950 reduces oxidative and inflammatory stress in stem cells under OGD-induced stress. These findings shed light on the causes of hDPSC and hMSC demise following transplantation and point to strategies to lessen therapeutic cell loss under ischemic-reperfusion stress.

The emerging role of pyroptosis-related inflammasome pathway in atherosclerosis

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

EV-A71 induced IL-1β production in THP-1 macrophages is dependent on NLRP3, RIG-I, and TLR3

Enterovirus A71 (EV-A71) is an emerging enterovirus that can cause neurological complications. Enhanced serum IL-1β levels were observed in EV-A71 patients with severe neurological symptoms. However, the roles of sensors in enterovirus-induced IL-1β production are unclear. In this study, we identified that pattern recognition receptors, including RIG-I, TLR3, and TLR8, are implicated in EV-A71-triggered IL-1β release in human macrophages. EV-A71 infection results in caspase-1 and caspase-8, which act as regulators of EV-A71-induced NLRP3 and RIG-I inflammasome activation. Moreover, knockdown of the expression of TLR3 and TLR8 decreased the released IL-1β in an NLRP3-dependent manner. Since TLR3 and TLR8 ligands promote NLRP3 inflammasome activation via caspase-8, the alternative pathway may be involved. In summary, these results indicate that activation of the NLRP3 and RIG-I inflammasomes in EV-A71-infected macrophages is mediated by caspase-1 and caspase-8 and affected by TLRs, including TLR3 and TLR8.

Cadmium exposure induces pyroptosis in testicular tissue by increasing oxidative stress and activating the AIM2 inflammasome pathway

High doses of cadmium (Cd) cause irreversible injury to the reproductive system, especially testicular tissue. Studies have shown that pyroptosis is involved in Cd-induced tissue damage, but whether pyroptosis is involved in damage to testicular tissue following Cd exposure remains unclear. To investigate the mechanism of pyroptosis in testicular injury induced by Cd exposure, we used 8-week-old male C57BL/6J mice subjected to consecutive 7 days of intraperitoneal injection of cadmium chloride (CdCl₂) at concentrations of 0, 1.0 and 3.0 mg/kg. The results indicated that 3.0 mg/kg CdCl₂ significantly decreased serum testosterone levels, sperm concentration and sperm motility, while increased LDH and IL-1β levels. Testicular HE staining indicated that Cd exposure damaged the interstitial cells and increased the atypical residual bodies. Fluorescence results indicated that 3.0 mg/kg CdCl₂ increased ROS levels, DNA damage, and the number of TUNEL-positive seminiferous tubule cells in testicular tissue. Transcriptome analysis showed that Cd exposure mainly induced inflammatory and chemokine signaling pathways in testicular tissue, with upregulated mRNA levels of Aim2, and reduced mRNA levels of Nlrp3. Further analysis showed that 3.0 mg/kg CdCl₂ increased the expression of testicular HO-1, SOD2, γH2AX and PARP-1, as well as the pyroptosis-related factors GSDMD, GSDME, Caspase-1, ASC and IL-1β. In conclusion, our results provide a possible mechanism by which Cd exposure activates the AIM2 pathway by increasing oxidative stress injury to induce pyroptosis in testicular tissue. This provides a new perspective on testicular damage caused by Cd exposure.

Mechanisms of Cd-induced Cytotoxicity in Normal Human Skin Keratinocytes: Implication for Human Health

Cadmium (Cd) is one of the toxic heavy metals found widely in the environment. Skin is an important target organ of Cd exposure. However, the adverse effects of Cd on human skin are still not well known. In this study, normal human skin keratinocytes (HaCaT cells) were studied for changes in cell viability, morphology, DNA damage, cycle, apoptosis, and the expression of endoplasmic reticulum (ER) stress-related genes (XBP-1, BiP, ATF-4, and CHOP) after exposure to Cd for 24 h. We found that Cd decreased cell viability in a concentration-dependent manner, with a median lethal concentration (LC₅₀) of 11 µM. DNA damage induction was evidenced by upregulation of the level of γ-H2AX. Furthermore, Cd induced G0/G1 phase cell cycle arrest and apoptosis in a dose-dependent manner and upregulated the mRNA levels of ER stress biomarker genes (XBP-1, BiP, ATF4, and CHOP). Taken together, our results showed that Cd induced cytotoxicity and DNA damage in HaCaT cells, eventually resulting in cell cycle arrest in the G0/G1 phase and apoptosis. In addition, ER stress may be involved in Cd-induced HaCaT apoptosis. Our data imply the importance of reducing Cd pollution in the environment to reduce its adverse impacts on human skin.

Therapeutic Implications of Targeting Pyroptosis in Cardiac-related Etiology of Heart Failure

Heart failure remains a considerable clinical and public health problem, it is the dominant cause of death from cardiovascular diseases, besides, cardiovascular diseases are one of the leading causes of death worldwide. The survival of patients with heart failure continues to be low with 45-60% reported deaths within five years. Apoptosis, necrosis, autophagy, and pyroptosis mediate cardiac cell death. Acute cell death is the hallmark pathogenesis of heart failure and other cardiac pathologies. Inhibition of pyroptosis, autophagy, apoptosis, or necrosis reduces cardiac damage and improves cardiac function in cardiovascular diseases. Pyroptosis is a form of inflammatory deliberate cell death that is characterized by the activation of inflammasomes such as NOD-like receptors (NLR), absent in melanoma 2 (AIM2), interferon-inducible protein 16 (IFI-16), and their downstream effector cytokines: Interleukin IL-1β and IL-18 leading to cell death. Recent studies have shown that pyroptosis is also the dominant cell death process in cardiomyocytes, cardiac fibroblasts, endothelial cells, and immune cells. It plays a crucial role in the pathogenesis of cardiac diseases that contribute to heart failure. This review intends to summarize the therapeutic implications targeting pyroptosis in the main cardiac pathologies preceding heart failure.

Gut-Flora-Dependent Metabolite Trimethylamine-N-Oxide Promotes Atherosclerosis-Associated Inflammation Responses by Indirect ROS Stimulation and Signaling Involving AMPK and SIRT1

Trimethylamine-N-oxide (TMAO), a gut-microbiota-dependent metabolite after ingesting dietary choline, has been identified as a novel risk factor for atherosclerosis through inducing vascular inflammation. However, the underlying molecular mechanism is poorly understood. Using an in vitro vascular cellular model, we found that the TMAO-induced inflammation responses were correlated with an elevation of ROS levels and downregulation of SIRT1 expression in VSMCs and HUVECs. The overexpression of SIRT1 could abrogate both the stimulation of ROS and inflammation. Further studies revealed that AMPK was also suppressed by TMAO and was a mediator upstream of SIRT1. Activation of AMPK by AICAR could reduce TMAO-induced ROS and inflammation. Moreover, the GSH precursor NAC could attenuate TMAO-induced inflammation. In vivo studies with mice models also showed that choline-induced production of TMAO and the associated glycolipid metabolic changes leading to atherosclerosis could be relieved by NAC and a probiotic LP8198. Collectively, the present study revealed an unrecognized mechanistic link between TMAO and atherosclerosis risk, and probiotics ameliorated TMAO-induced atherosclerosis through affecting the gut microbiota. Consistent with previous studies, our data confirmed that TMAO could stimulate inflammation by modulating cellular ROS levels. However, this was not due to direct cytotoxicity but through complex signaling pathways involving AMPK and SIRT1.

Cyclovirobuxine D Ameliorates Experimental Diabetic Cardiomyopathy by Inhibiting Cardiomyocyte Pyroptosis via NLRP3 in vivo and in vitro

Diabetic cardiomyopathy (DCM) is one of the common complications of diabetic patients, which can induce myocardial hypertrophy, cardiac fibrosis, and heart failure. Growing evidence has shown that the occurrence and development of DCM are accompanied by pyroptosis which is an NLRP3-mediated intense inflammatory cell death. Cyclovirobuxine D (CVB-D) has been shown to significantly ameliorate DCM and anti-inflammatory effects associated with cardiomyopathy, but it is unclear whether it has an effect on cardiomyocyte pyroptosis accompanying DCM. Therefore, the purpose of the present study was to explore the ameliorating effect of CVB-D on cardiomyocyte pyroptosis associated with DCM and its molecular regulation mechanism. Type 2 diabetes in C57BL/6 mice was reproduced by the high-fat and high-glucose diet (HFD) combined with low-dose streptozotocin (STZ). The characteristics of DCM were evaluated by cardiac ultrasonography, serum detection, and histopathological staining. The results suggested that CVB-D could significantly alleviate the cardiac pathology of DCM. Then, we explored the mechanism of CVB-D on primary neonatal rat cardiomyocyte (PNRCM) injury with high glucose (HG) in vitro to simulate the physiological environment of DCM. Preincubation with CVB-D could significantly increase cell viability, attenuate cytopathological changes and inhibit the expression levels of pyroptosis-related proteins. Further research found that the myocardial improvement effect of CVB-D was related to its inhibition of NLRP3 expression. In conclusion, our data suggest that CVB-D can ameliorate DCM by inhibiting cardiomyocyte pyroptosis via NLRP3, providing a novel molecular target for CVB-D clinical application.

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.

Angiotensin-(1-7), a protective peptide against vascular aging

Vascular aging is a complex and multifaceted process that provokes profound molecular, structural, and functional changes in the vasculature. Eventually, these profound aging alterations make arteries more prone to vascular disease, including hypertension, atherosclerosis and other arterial complications that impact the organism beyond the cardiovascular system and accelerate frailty. For these reasons, preventing or delaying the hallmarks of vascular aging is nowadays a major health goal, especially in our aged societies. In this context, angiotensin(Ang)-(1-7), a major player of the protective branch of the renin-angiotensin system, has gained relevance over recent years as growing knowledge on its anti-aging properties is being unveiled. Here, we briefly review the main actions of Ang-(1-7) against vascular aging. These include protection against vascular cell senescence, anti-inflammatory and antioxidant effects together with the induction of cytoprotective systems. Ang-(1-7) further ameliorates endothelial dysfunction, a hallmark of vascular aging and disease, attenuates fibrosis and calcification and promotes protective angiogenesis and repair. Although further research is needed to better understand the anti-aging properties of Ang-(1-7) on the vasculature, this heptapeptide arises as a promising pharmacological tool for preventing vascular aging and frailty.

Galangin attenuates cadmium-evoked nephrotoxicity: Targeting nucleotide-binding domain-like receptor pyrin domain containing 3 inflammasome, nuclear factor erythroid 2-related factor 2, and nuclear factor kappa B signaling

The kidney is highly vulnerable to cadmium-evoked oxidative injury. Galangin is a natural flavone with reported antioxidant properties. This study investigated the potential modulating activity of galangin against cadmium-induced nephrotoxicity and explored the underlining mechanisms. Western blot analysis, spectrophotometric, ELISA, and histopathological techniques were employed. The results revealed that galangin suppressed tubular injury and improved glomerular function in the cadmium-intoxicated rats as evidenced by downregulation of kidney injury molecule-1, serum creatinine, and blood urea nitrogen. Galangin reduced cadmium-evoked inflammatory response and oxidative stress as indicated by reduced levels of interleukin-1 beta and TNF-α, decreased DNA damage, and improved antioxidant potential of the renal tissues. Mechanistically, galangin suppressed the nucleotide-binding domain-like receptor pyrin domain containing 3 inflammasome and efficiently decreased caspase-1 activity in the cadmium-intoxicated rats. Equally important, it inhibited the cadmium-induced nuclear translocation of nuclear factor kappa B and upregulated nuclear factor erythroid 2-related factor 2 signaling. The results highlight the ability of galangin to attenuate cadmium-evoked nephrotoxicity and support its therapeutic implementation although clinical investigations are warranted.

Pratensein Mitigates Oxidative Stress and NLRP3 Inflammasome Activation in OGD/R-Injured HT22 Cells by Activating Nrf2-Anti-oxidant Signaling

The current investigation seeks to uncover the neuroprotective effects and mechanisms of pratensein (Pra) against cerebral ischemia-reperfusion (CI/R) injury. An in vitro model was created by subjecting HT22 cells to oxygen-glucose deprivation/reoxygenation (OGD/R) injury. Various doses of Pra were administered to HT22 cells during the process of OGD/R. Nrf2 knockdown was achieved by siRNA transfection. Pra antagonized OGD/R-triggered HT22 cell damage, as suggested by increased cell viability and reduced levels of LDH secretion. Additionally, Pra reversed OGD/R-induced cell apoptosis, oxidative stress, and inflammatory injury. Transfection of Nrf2 siRNA partially ameliorated the protective effects of Pra on the OGD/R-stimulated increase in cell apoptosis, oxidative stress, and inflammatory response in HT22 cells. Pra significantly inhibited the expression of nod-like-receptor-protein-3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, and cleaved caspase-1 protein in OGD/R-induced cells. Nrf2 knockdown reversed the benefits of Pra on NLRP3 inflammasome activation. Besides, Pra administration mitigated middle cerebral artery occlusion/reperfusion-induced cerebral infarction, neurological deficits, and neuronal apoptosis in vivo. This study found that Pra suppresses NLRP3 inflammasome activation through Nrf2 activation, resulting in reduced inflammatory responses and rates of apoptosis in OGD/R-stimulated HT22 cells, highlighting the neuroprotective properties of Pra in CI/R.

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.

IL-1β Impacts Vascular Integrity and Lymphatic Function in the Embryonic Omentum

BACKGROUND

The chromatin-remodeling enzyme BRG1 (brahma-related gene 1) regulates gene expression in a variety of rapidly differentiating cells during embryonic development. However, the critical genes that BRG1 regulates during lymphatic vascular development are unknown.

METHODS

We used genetic and imaging techniques to define the role of BRG1 in murine embryonic lymphatic development, although this approach inadvertently expanded our study to multiple interacting cell types.

RESULTS

We found that omental macrophages fine-tune an unexpected developmental process by which erythrocytes escaping from naturally discontinuous omental blood vessels are collected by nearby lymphatic vessels. Our data indicate that circulating fibrin(ogen) leaking from gaps in omental blood vessels can trigger inflammasome-mediated IL-1β (interleukin-1β) production and secretion from nearby macrophages. IL-1β destabilizes adherens junctions in omental blood and lymphatic vessels, contributing to both extravasation of erythrocytes and their uptake by lymphatics. BRG1 regulates IL-1β production in omental macrophages by transcriptionally suppressing the inflammasome trigger RIPK3 (receptor interacting protein kinase 3).

CONCLUSIONS

Genetic deletion of Brg1 in embryonic macrophages leads to excessive IL-1β production, erythrocyte leakage from blood vessels, and blood-filled lymphatics in the developing omentum. Altogether, these results highlight a novel context for epigenetically regulated crosstalk between macrophages, blood vessels, and lymphatics.

Autophagy, Pyroptosis, and Ferroptosis: New Regulatory Mechanisms for Atherosclerosis

Atherosclerosis is a chronic inflammatory disorder characterized by the gradual buildup of plaques within the vessel wall of middle-sized and large arteries. The occurrence and development of atherosclerosis and the rupture of plaques are related to the injury of vascular cells, including endothelial cells, smooth muscle cells, and macrophages. Autophagy is a subcellular process that plays an important role in the degradation of proteins and damaged organelles, and the autophagy disorder of vascular cells is closely related to atherosclerosis. Pyroptosis is a proinflammatory form of regulated cell death, while ferroptosis is a form of regulated nonapoptotic cell death involving overwhelming iron-dependent lipid peroxidation. Both of them exhibit distinct features from apoptosis, necrosis, and autophagy in morphology, biochemistry, and genetics. However, a growing body of evidence suggests that pyroptosis and ferroptosis interact with autophagy and participate in the development of cancers, degenerative brain diseases and cardiovascular diseases. This review updated the current understanding of autophagy, pyroptosis, and ferroptosis, finding potential links and their effects on atherogenesis and plaque stability, thus providing ways to develop new pharmacological strategies to address atherosclerosis and stabilize vulnerable, ruptured plaques.

Pyroptosis and Its Regulation in Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DbCM) is a prevalent disease, characterized by contractile dysfunction and left ventricular hypertrophy. Patients with DbCM have high morbidity and mortality worldwide. Recent studies have identified that pyroptosis, a kind of cell death, could be induced by hyperglycemia involved in the formation of DbCM. This review summarizes the regulatory mechanisms of pyroptosis in DbCM, including NOD-like receptor3, AIM2 inflammasome, long non-coding RNAs, microRNAs, circular RNA, autophagy, and some drugs.

Focus on ferroptosis, pyroptosis, apoptosis and autophagy of vascular endothelial cells to the strategic targets for the treatment of atherosclerosis

Vascular endothelial cells (VECs), which are lined up in the inner surface of blood vessels, are in direct contact with the metabolite-related endogenous danger signals in the circulatory system. Moreover, VECs death impairs vasodilation and increases endothelium-dependent permeability, which is strongly correlated with the development of atherosclerosis (AS). Among several forms of cell death, regulatory death of endothelial cells frequently occurs in AS, mainly including ferroptosis, pyroptosis, apoptosis and autophagy. In this review, we summarize regulatory factors and signaling mechanisms of regulatory death in endothelial cells, discussing their effects in the context of the atherosclerotic procession.

Spotlight on NLRP3 Inflammasome: Role in Pathogenesis and Therapies of Atherosclerosis

Inflammation is an intricate biological response of body tissues to detrimental stimuli. Cardiovascular disease (CVD) is the leading cause of death worldwide, and inflammation is well documented to play a role in the development of CVD, especially atherosclerosis (AS). Emerging evidence suggests that activation of the NOD-like receptor (NLR) family and the pyridine-containing domain 3 (NLRP3) inflammasome is instrumental in inflammation and may result in AS. The NLRP3 inflammasome acts as a molecular platform that triggers the activation of caspase-1 and the cleavage of pro-interleukin (IL)-1β, pro-IL-18, and gasdermin D (GSDMD). The cleaved GSDMD forms pores in the cell membrane and initiates pyroptosis, inducing cell death and the discharge of intracellular pro-inflammatory factors. Hence, the NLRP3 inflammasome is a promising target for anti-inflammatory therapy against AS. In this review, we systematically summarized the current understanding of the activation mechanism of NLRP3 inflammasome, and the pathological changes in AS involving NLRP3. We also discussed potential therapeutic strategies targeting NLRP3 inflammasome to combat AS.