Lupenone improves motor dysfunction in spinal cord injury mice through inhibiting the inflammasome activation and pyroptosis in microglia via the nuclear factor kappa B pathway

Spinal cord injury-induced motor dysfunction is associated with neuroinflammation.Studies have shown that the triterpenoid lupenone,a natural product found in various plants,has a remarkable anti-inflammatory effect in the context of chronic inflammation.However,the effects of lupenone on acute inflammation induced by spinal cord injury remain unknown.In this study,we established an impact-induced mouse model of spinal cord injury,and then treated the injured mice with lupenone(8 mg/kg,twice a day)by intrape ritoneal injection.We also treated BV2 cells with lipopolysaccharide and adenosine5’-triphosphate to simulate the inflammatory response after spinal cord injury.Our res ults showed that lupenone reduced IKBa activation and p65 nuclear translocation,inhibited NLRP3 inflammasome function by modulating nuclear factor kappa B,and enhanced the conve rsion of proinflammatory M1 mic roglial cells into anti-inflammatory M2 microglial cells.Furthermore,lupenone decreased NLRP3 inflammasome activation,NLRP3-induced mic roglial cell polarization,and microglia pyroptosis by inhibiting the nuclear factor kappa B pathway.These findings suggest that lupenone protects against spinal cord injury by inhibiting inflammasomes.

Conditioned medium from human dental pulp stem cells treats spinal cord injury by inhibiting microglial pyroptosis

Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear.In the present study,we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells.We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury,decreased expression of the microglial pyroptosis markers NLRP3,GSDMD,caspase-1,and interleukin-1β,promoted axonal and myelin regeneration,and inhibited the formation of glial scars.In addition,in a lipopolysaccharide-induced BV2 microglia model,conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway.These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway,thereby promoting the recovery of neurological function after spinal cord injury.Therefore,conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.

Crosstalk among mitophagy,pyroptosis,ferroptosis,and necroptosis in central nervous system injuries

Central nervous system injuries have a high rate of resulting in disability and mortality;however,at present,effective treatments are lacking.Programmed cell death,which is a genetically determined fo rm of active and ordered cell death with many types,has recently attra cted increasing attention due to its functions in determining the fate of cell survival.A growing number of studies have suggested that programmed cell death is involved in central nervous system injuries and plays an important role in the progression of brain damage.In this review,we provide an ove rview of the role of programmed cell death in central nervous system injuries,including the pathways involved in mitophagy,pyroptosis,ferroptosis,and necroptosis,and the underlying mechanisms by which mitophagy regulates pyroptosis,ferroptosis,and necro ptosis.We also discuss the new direction of therapeutic strategies to rgeting mitophagy for the treatment of central nervous system injuries,with the aim to determine the connection between programmed cell death and central nervous system injuries and to identify new therapies to modulate programmed cell death following central nervous system injury.In conclusion,based on these properties and effects,interventions targeting programmed cell death could be developed as potential therapeutic agents for central nervous system injury patients.

NLRP3/1-mediated pyroptosis:beneficial clues for the development of novel therapies for Alzheimer’s disease

The inflammasome is a multiprotein complex involved in innate immunity that mediates the inflammatory response leading to pyroptosis,which is a lytic,inflammatory form of cell death.There is accumulating evidence that nucleotide-binding domain and leucine-rich repeat pyrin domain containing 3(NLRP3)inflammasome-mediated microglial pyroptosis and NLRP1 inflammasome-mediated neuronal pyroptosis in the brain are closely associated with the pathogenesis of Alzheimer’s disease.In this review,we summarize the possible pathogenic mechanisms of Alzheimer’s disease,focusing on neuroinflammation.We also describe the structures of NLRP3 and NLRP1 and the role their activation plays in Alzheimer’s disease.Finally,we examine the neuroprotective activity of small-molecule inhibitors,endogenous inhibitor proteins,microRNAs,and natural bioactive molecules that target NLRP3 and NLRP1,based on the rationale that inhibiting NLRP3 and NLRP1 inflammasome-mediated pyroptosis can be an effective therapeutic strategy for Alzheimer’s disease.

Membrane vesicles derived from Streptococcus suis serotype 2 induce cell pyroptosis in endothelial cells via the NLRP3/Caspase-1/GSDMD pathway

Streptococcus suis serotype 2(S.suis 2)is a zoonotic pathogen that clinically causes severe swine and human infections(such as meningitis,endocarditis,and septicemia).In order to cause widespread diseases in different organs,S.suis 2 must colonize the host,break the blood barrier,and cause exaggerated inflammation.In the last few years,most studies have focused on a single virulence factor and its influences on the host.Membrane vesicles(MVs)can be actively secreted into the extracellular environment contributing to bacteria-host interactions.Gram-negative bacteria-derived outer membrane vesicles(OMVs)were recently shown to activate host Caspase-11-mediated non-canonical inflammasome pathway via deliverance of OMV-bound lipopolysaccharide(LPS),causing host cell pyroptosis.However,little is known about the effect of the MVs from S.suis 2(Gram-positive bacteria without LPS)on cell pyroptosis.Thus,we investigated the molecular mechanism by which S.suis 2 MVs participate in endothelial cell pyroptosis.In this study,we used proteomics,electron scanning microscopy,fluorescence microscope,Western blotting,and bioassays,to investigate the MVs secreted by S.suis 2.First,we demonstrated that S.suis 2 secreted MVs with an average diameter of 72.04 nm,and 200 proteins in MVs were identified.Then,we showed that MVs were transported to cells via mainly dynamin-dependent endocytosis.The S.suis 2 MVs activated NLRP3/Caspase-1/GSDMD canonical inflammasome signaling pathway,resulting in cell pyroptosis,but it did not activate the Caspase-4/-5 pathway.More importantly,endothelial cells produce large amounts of reactive oxygen species(ROS)and lost their mitochondrial membrane potential under induction by S.suis 2 MVs.The results in this study suggest for the first time that MVs from S.suis 2 were internalized by endothelial cells via mainly dynamin-dependent endocytosis and might promote NLRP3/Caspase-1/GSDMD pathway by mitochondrial damage,which produced mtDNA and ROS under induction,leading to the pyroptosis of endothelial cells.

Icariin plus curcumol enhances autophagy through the mTOR pathway and promotes cathepsin B-mediated pyroptosis of prostate cancer cells

Objective:To examine the effect of icariin plus curcumol on prostate cancer cells PC3 and elucidate the underlying mechanisms.Methods:We employed the Cell Counting Kit 8 assay and colony formation assay to assess cell viability and proliferation.Autophagy expression was analyzed using monodansylcadaverine staining.Immunofluorescence and Western blot analyses were used to evaluate protein expressions related to autophagy,pyroptosis,and the mTOR pathway.Cellular damage was examined using the lactate dehydrogenase assay.Moreover,cathepsin B and NLRP3 were detected by co-immunoprecipitation.Results:Icariin plus curcumol led to a decrease in PC3 cell proliferation and an enhancement of autophagy.The levels of LC3-Ⅱ/LC3-Ⅰand beclin-1 were increased,while the levels of p62 and mTOR were decreased after treatment with icariin plus curcumol.These changes were reversed upon overexpression of mTOR.Furthermore,3-methyladenine resulted in a decrease in inflammatory cytokines,pyroptosis-related protein levels,and lactate dehydrogenase concentration,compared to the icariin plus curcumol group.Inhibiting cathepsin B reversed the regulatory effects of icariin plus curcumol.Conclusions:Icariin plus curcumol demonstrates great potential as a therapeutic agent for castration-resistant prostate cancer by enhancing autophagy via the mTOR pathway and promoting pyroptosis mediated by cathepsin B.These findings provide valuable insights into the molecular mechanisms underlying the therapeutic potential of icariin and curcumol for prostate cancer treatment.

Mesenteric adipose tissue B lymphocytes promote intestinal injury in severe acute pancreatitis by mediating enteric pyroptosis

Background:Visceral adipose tissue(VAT)has been linked to the severe acute pancreatitis(SAP)prognosis,although the underlying mechanism remains unclear.It has been reported that pyroptosis worsens SAP.The present study aimed to verify whether mesenteric adipose tissue(MAT,a component of VAT)can cause secondary intestinal injury through the pyroptotic pathway.Methods:Thirty-six male Sprague Dawley(SD)rats were divided into six different groups.Twelve rats were randomly divided into the SAP and control groups.We monitored the changes of MAT and B lymphocytes infiltration in MAT of SAP rats.Twelve SAP rats were injected with MAT B lymphocytes or phosphate buffer solution(PBS).The remaining twelve SAP rats were first injected with MAT B lymphocytes,and then with MCC950(NLRP3 inhibitor)or PBS.We collected blood and tissue samples from pancreas,gut and MAT for analysis.Results:Compared to the control rats,the SAP group showed inflammation in MAT,including higher expression of tumor necrosis factor(TNF-α)and interleukin-6(IL-6),lower expression of IL-10,and histological changes.Flow cytometry analysis revealed B lymphocytes infiltration in MAT but not T lymphocytes and macrophages.The SAP rats also exhibited intestinal injury,characterized by lower expression of zonula occludens-1(ZO-1)and occludin,higher levels of lipopolysaccharide and diamine oxidase,and pathological changes.The expression of NLRP3 and n-GSDMD,which are responsible for pyroptosis,was increased in the intestine of SAP rats.The injection of MAT B lymphocytes into SAP rats exacerbated the inflammation in MAT.The upregulation of pyroptosis reduced tight junction in the intestine,which contributed to the SAP progression,including higher inflammatory indicators and worse histological changes.The administration of MCC950 to SAP+MAT B rats downregulated pyroptosis,which subsequently improved the intestinal barrier and ameliorated inflammatory response of SAP.Conclusions:In SAP,MAT B lymphocytes aggravated local inflammation,and promoted the injury to the intestine through the enteric pyroptotic pathway.

Tumor necrosis factor-stimulated gene-6 ameliorates early brain injury after subarachnoid hemorrhage by suppressing NLRC4 inflammasome-mediated astrocyte pyroptosis

Subarachnoid hemorrhage is associated with high morbidity and mortality and lacks effective treatment.Pyroptosis is a crucial mechanism underlying early brain injury after subarachnoid hemorrhage.Previous studies have confirmed that tumor necrosis factor-stimulated gene-6(TSG-6)can exert a neuroprotective effect by suppressing oxidative stress and apoptosis.However,no study to date has explored whether TSG-6 can alleviate pyroptosis in early brain injury after subarachnoid hemorrhage.In this study,a C57BL/6J mouse model of subarachnoid hemorrhage was established using the endovascular perforation method.Our results indicated that TSG-6 expression was predominantly detected in astrocytes,along with NLRC4 and gasdermin-D(GSDMD).The expression of NLRC4,GSDMD and its N-terminal domain(GSDMD-N),and cleaved caspase-1 was significantly enhanced after subarachnoid hemorrhage and accompanied by brain edema and neurological impairment.To explore how TSG-6 affects pyroptosis during early brain injury after subarachnoid hemorrhage,recombinant human TSG-6 or a siRNA targeting TSG-6 was injected into the cerebral ventricles.Exogenous TSG-6 administration downregulated the expression of NLRC4 and pyroptosis-associated proteins and alleviated brain edema and neurological deficits.Moreover,TSG-6 knockdown further increased the expression of NLRC4,which was accompanied by more severe astrocyte pyroptosis.In summary,our study revealed that TSG-6 provides neuroprotection against early brain injury after subarachnoid hemorrhage by suppressing NLRC4 inflammasome activation-induced astrocyte pyroptosis.

SLC6A14 promotes ulcerative colitis progression by facilitating NLRP3 inflammasome-mediated pyroptosis

BACKGROUND Ulcerative colitis(UC)is an inflammatory condition with frequent relapse and recurrence.Evidence suggests the involvement of SLC6A14 in UC pathogenesis,but the central regulator remains unknown.AIM To explore the role of SLC6A14 in UC-associated pyroptosis.METHODS Quantitative real-time polymerase chain reaction(qRT-PCR),immunoblotting,and immunohistochemical were used to assess SLC6A14 in human UC tissues.Lipopolysaccharide(LPS)was used to induce inflammation in FHC and NCM460 cells and model enteritis,and SLC6A14 levels were assessed.Pyroptosis markers were quantified using enzyme-linked immunosorbent assay,Western blotting,and qRT-PCR,and EdU incubation,CCK-8 assays and flow cytometry were used to examine proliferation and apoptosis.Mouse models of UC were used for verification.RESULTS SLC6A14 was increased and correlated with NLRP3 in UC tissues.LPS-induced FHC and NCM460 cells showed increased SLC6A14 levels.Reducing SLC6A14 increased cell proliferation and suppressed apoptosis.Reducing SLC6A14 decreased pyroptosis-associated proteins(ASC,IL-1β,IL-18,NLRP3).NLRP3 overexpression counteracted the effects of sh-SLC6A14 on LPS-induced FHC and NCM460 cell pyroptosis.SLC6A14 improved the mucosa in mice with dextran sulfate sodium-induced colitis.CONCLUSION SLC6A14 promotes UC pyroptosis by regulating NLRP3,suggesting the therapeutic potential of modulating the SLC6A14/NLRP3 axis.

Lacticaseibacillus rhamnosus Fmb14 ameliorates hyperuricemia-induced hepatocyte pyroptosis via NLRP3 inflammasome cascade inhibition

Hyperuricemia is a high-risk factor for the development of gout and renal fibrosis,but the adverse effects of hyperuricemia on the liver have been seriously neglected.This research investigated the ameliorating effect of Lacticaseibacillus rhamnosus Fmb14 on hyperuricemia induced liver dysfunction both in vitro and in vivo.Cell free extracts of high dose L.rhamnosus Fmb14 treatment reduced the death rate of HepG2 cell lines from 24.1%to 14.9%by inhibiting NLRP3 recruitment,which was mainly activated by reactive oxygen species release and mitochondrial membrane potential disorder.In purine dietary induced hyperuricemia(PDIH)mice model,liver oedema and pyroptosis were ameliorated after L.rhamnosus Fmb14 administration through downregulating the expression levels of NLRP3,caspase-1 and gasdermin-D from 1.61 to 0.86,3.15 to 1.01 and 5.63 to 2.02,respectively.L.rhamnosus Fmb14 administration restored mitochondrial inner membrane protein(MPV17)and connexin 43 from 2.83 and 0.73 to 0.80 and 0.98 respectively in PDIH mice,indicating that dysbiosis of mitochondrial membrane potential was restored in liver.Intriguingly,PDIH pyroptosis stimulates the process of apoptosis,which leads to severe leakage of hepatocytes,and both of pyroptosis and apoptosis were decreased after L.rhamnosus Fmb14 treatment.Therefore,L.rhamnosus Fmb14 is a promising biological resource to maintain homeostasis of the liver in hyperuricemia and the prevention of subsequent complications.

Identification and validation of a pyroptosis-related prognostic model for colorectal cancer based on bulk and single-cell RNA sequencing data

BACKGROUND Pyroptosis impacts the development of malignant tumors,yet its role in colorectal cancer(CRC)prognosis remains uncertain.AIM To assess the prognostic significance of pyroptosis-related genes and their association with CRC immune infiltration.METHODS Gene expression data were obtained from The Cancer Genome Atlas(TCGA)and single-cell RNA sequencing dataset GSE178341 from the Gene Expression Omnibus(GEO).Pyroptosis-related gene expression in cell clusters was analyzed,and enrichment analysis was conducted.A pyroptosis-related risk model was developed using the LASSO regression algorithm,with prediction accuracy assessed through K-M and receiver operating characteristic analyses.A nomo-gram predicting survival was created,and the correlation between the risk model and immune infiltration was analyzed using CIBERSORTx calculations.Finally,the differential expression of the 8 prognostic genes between CRC and normal samples was verified by analyzing TCGA-COADREAD data from the UCSC database.RESULTS An effective pyroptosis-related risk model was constructed using 8 genes-CHMP2B,SDHB,BST2,UBE2D2,GJA1,AIM2,PDCD6IP,and SEZ6L2(P<0.05).Seven of these genes exhibited differential expression between CRC and normal samples based on TCGA database analysis(P<0.05).Patients with higher risk scores demonstrated increased death risk and reduced overall survival(P<0.05).Significant differences in immune infiltration were observed between low-and high-risk groups,correlating with pyroptosis-related gene expression.CONCLUSION We developed a pyroptosis-related prognostic model for CRC,affirming its correlation with immune infiltration.This model may prove useful for CRC prognostic evaluation.

Exosomal miR-23b from bone marrow mesenchymal stem cells alleviates oxidative stress and pyroptosis after intracerebral hemorrhage

Our previous studies showed that miR-23b was downregulated in patients with intracerebral hemorrhage(ICH). This indicates that miR-23b may be closely related to the patho-physiological mechanism of ICH, but this hypothesis lacks direct evidence. In this study, we established rat models of ICH by injecting collagenase Ⅶ into the right basal ganglia and treating them with an injection of bone marrow mesenchymal stem cell(BMSC)-derived exosomal miR-23b via the tail vein. We found that edema in the rat brain was markedly reduced and rat behaviors were improved after BMSC exosomal miR-23b injection compared with those in the ICH groups. Additionally, exosomal miR-23b was transported to the microglia/macrophages, thereby reducing oxidative stress and pyroptosis after ICH. We also used hemin to mimic ICH conditions in vitro. We found that phosphatase and tensin homolog deleted on chromosome 10(PTEN) was the downstream target gene of miR-23b, and exosomal miR-23b exhibited antioxidant effects by regulating the PTEN/Nrf2 pathway. Moreover, miR-23b reduced PTEN binding to NOD-like receptor family pyrin domain containing 3(NLRP3) and NLRP3 inflammasome activation, thereby decreasing the NLRP3-dependent pyroptosis level. These findings suggest that BMSC-derived exosomal miR-23b exhibits antioxidant effects through inhibiting PTEN and alleviating NLRP3 inflammasome-mediated pyroptosis, thereby promoting neurologic function recovery in rats with ICH.

Neuronal nitric oxide synthase/reactive oxygen species pathway is involved in apoptosis and pyroptosis in epilepsy

Dysfunction of neuronal nitric oxide synthase contributes to neurotoxicity,which triggers cell death in various neuropathological diseases,including epilepsy.Studies have shown that inhibition of neuronal nitric oxide synthase activity increases the epilepsy threshold,that is,has an anticonvulsant effect.However,the exact role and potential mechanism of neuronal nitric oxide synthase in seizures are still unclear.In this study,we performed RNA sequencing,functional enrichment analysis,and weighted gene coexpression network analysis of the hippocampus of tremor rats,a rat model of genetic epilepsy.We found damaged hippocampal mitochondria and abnormal succinate dehydrogenase level and Na+-K+-ATPase activity.In addition,we used a pilocarpine-induced N2a cell model to mimic epileptic injury.After application of neuronal nitric oxide synthase inhibitor 7-nitroindazole,changes in malondialdehyde,lactate dehydrogenase and superoxide dismutase,which are associated with oxidative stress,were reversed,and the increase in reactive oxygen species level was reversed by 7-nitroindazole or reactive oxygen species inhibitor N-acetylcysteine.Application of 7-nitroindazole or N-acetylcysteine downregulated the expression of caspase-3 and cytochrome c and reversed the apoptosis of epileptic cells.Furthermore,7-nitroindazole or N-acetylcysteine downregulated the abnormally high expression of NLRP3,gasdermin-D,interleukin-1βand interleukin-18.This indicated that 7-nitroindazole and N-acetylcysteine each reversed epileptic cell death.Taken together,our findings suggest that the neuronal nitric oxide synthase/reactive oxygen species pathway is involved in pyroptosis of epileptic cells,and inhibiting neuronal nitric oxide synthase activity or its induced oxidative stress may play a neuroprotective role in epilepsy.

Protocatechuic acid and quercetin attenuate ETEC-caused IPEC-1 cell inflammation and injury associated with inhibition of necroptosis and pyroptosis signaling pathways

Background:Necroptosis and pyroptosis are newly identified forms of programmed cell death,which play a vital role in development of many gastrointestinal disorders.Although plant polyphenols have been reported to protect intestinal health,it is still unclear whether there is a beneficial role of plant polyphenols in modulating necroptosis and pyroptosis in intestinal porcine epithelial cell line(IPEC-1)infected with enterotoxigenic Escherichia coli(ETEC)K88.This research was conducted to explore whether plant polyphenols including protocatechuic acid(PCA)and quercetin(Que),attenuated inflammation and injury of IPEC-1 caused by ETEC K88 through regulating necroptosis and pyroptosis signaling pathways.Methods:IPEC-1 cells were treated with PCA(40μmol/L)or Que(10μmol/L)in the presence or absence of ETEC K88.Results:PCA and Que decreased ETEC K88 adhesion and endotoxin level(P<0.05)in cell supernatant.PCA and Que increased cell number(P<0.001)and decreased lactate dehydrogenases(LDH)activity(P<0.05)in cell supernatant after ETEC infection.PCA and Que improved transepithelial electrical resistance(TEER)(P<0.001)and reduced fluorescein isothiocyanate-labeled dextran(FD4)flux(P<0.001),and enhanced membrane protein abundance of occludin,claudin-1 and ZO-1(P<0.05),and rescued distribution of these tight junction proteins(P<0.05)after ETEC infection.PCA and Que also declined cell necrosis ratio(P<0.05).PCA and Que reduced mRNA abundance and concentration of tumor necrosis factor-α(TNF-α),interleukin(IL)-6 and IL-8(P<0.001),and down-regulated gene expression of toll-like receptors 4(TLR4)and its downstream signals(P<0.001)after ETEC infection.PCA and Que down-regulated protein abundance of total receptor interacting protein kinase 1(t-RIP1),phosphorylated-RIP1(p-RIP1),p-RIP1/t-RIP1,t-RIP3,p-RIP3,mixed lineage kinase domain-like protein(MLKL),p-MLKL,dynamin-related protein 1(DRP1),phosphoglycerate mutase 5(PGAM5)and high mobility group box 1(HMGB1)(P<0.05)after ETEC infection.Moreover,PCA and Que reduced protein abundance of nod-like receptor protein 3(NLRP3),nod-like receptors family CARD domain-containing protein 4(NLRC4),apoptosis-associated speck-like protein containing a CARD(ASC),gasdermin D(GSDMD)and caspase-1(P<0.05)after ETEC infection.Conclusions:In general,our data suggest that PCA and Que are capable of attenuating ETEC-caused intestinal inflammation and damage via inhibiting necroptosis and pyroptosis signaling pathways.

Knockdown of NADPH oxidase 4 reduces mitochondrial oxidative stress and neuronal pyroptosis following intracerebral hemorrhage

Intracerebral hemorrhage is often accompanied by oxidative stress induced by reactive oxygen species,which causes abnormal mitochondrial function and secondary reactive oxygen species generation.This creates a vicious cycle leading to reactive oxygen species accumulation,resulting in progression of the pathological process.Therefore,breaking the cycle to inhibit reactive oxygen species accumulation is critical for reducing neuronal death after intracerebral hemorrhage.Our previous study found that increased expression of nicotinamide adenine dinucleotide phosphate oxidase 4(NADPH oxidase 4,NOX4)led to neuronal apoptosis and damage to the blood-brain barrier after intracerebral hemorrhage.The purpose of this study was to investigate the role of NOX4 in the circle involving the neuronal tolerance to oxidative stress,mitochondrial reactive oxygen species and modes of neuronal death other than apoptosis after intracerebral hemorrhage.We found that NOX4 knockdown by adeno-associated virus(AAV-NOX4)in rats enhanced neuronal tolerance to oxidative stress,enabling them to better resist the oxidative stress caused by intracerebral hemorrhage.Knockdown of NOX4 also reduced the production of reactive oxygen species in the mitochondria,relieved mitochondrial damage,prevented secondary reactive oxygen species accumulation,reduced neuronal pyroptosis and contributed to relieving secondary brain injury after intracerebral hemorrhage in rats.Finally,we used a mitochondria-targeted superoxide dismutase mimetic to explore the relationship between reactive oxygen species and NOX4.The mitochondria-targeted superoxide dismutase mimetic inhibited the expression of NOX4 and neuronal pyroptosis,which is similar to the effect of AAV-NOX4.This indicates that NOX4 is likely to be an important target for inhibiting mitochondrial reactive oxygen species production,and NOX4 inhibitors can be used to alleviate oxidative stress response induced by intracerebral hemorrhage.

MicroRNA-29a-3p Prevents Drug-Induced Acute Liver Failure through Inflammation-Related Pyroptosis Inhibition

Objective Little is known about the role of microRNA-29a-3p(miR-29a-3p)in inflammation-related pyroptosis,especially in drug-induced acute liver failure(DIALF).This study aimed to identify the relationship between miR-29a-3p and inflammation-related pyroptosis in DIALF and confirm its underlying mechanisms.Methods Thioacetamide(TAA)-and acetaminophen(APAP)-induced ALF mouse models were established,and human samples were collected.The expression levels of miR-29a-3p and inflammation and pyroptosis markers were measured by quantitative real-time polymerase chain reaction(qRT-PCR),Western blotting,or immunochemical staining in miR-29a-3p knock-in transgenic mouse(MIR29A(KI/KI))DIALF models.In addition,RNA sequencing was conducted to explore the mechanisms.Results MiR-29a-3p levels were decreased in TAA-and APAP-induced DIALF models.MiR-29a-3p prevented DIALF caused by TAA and APAP.RNA sequencing and further experiments showed that the protective effect of miR-29a-3p on DIALF was mainly achieved through inhibition of inflammation-related pyroptosis,and the inhibition was dependent on activation of the PI3K/AKT pathway.In addition,miR-29a-3p levels were reduced,and pyroptosis was activated in both peripheral blood mononuclear cells and liver tissues of DIALF patients.Conclusion The study supports the idea that miR-29a-3p inhibits pyroptosis by activating the PI3K/AKT pathway to prevent DIALF.MiR-29a-3p may be a promising therapeutic target for DIALF.

Pyroptosis and its role in cancer

Programmed cell death(PCD)is mediated by specific genes that encode signals.It can balance cell survival and death.Pyroptosis is a type of inflammatory,caspase-dependent PCD mediated by gasdermin proteins,which function in pore formation,cell expansion,and plasma membrane rupture,followed by the release of intracellular contents.Pyroptosis is mediated by caspase-1/3/4/5/11 and is primarily divided into the classical pathway,which is dependent on caspase-1,and the non-classical pathway,which is dependent on caspase-4/5/11.Inflam-masomes play a vital role in these processes.The various components of the pyroptosis pathway are related to the occurrence,invasion,and metastasis of tumors.Research on pyroptosis has revealed new options for tumor treatment.This article summarizes the recent research progress on the molecular mechanism of pyroptosis,the relationship between the various components of the pyroptosis pathway and cancer,and the applications and prospects of pyroptosis in anticancer therapy.

TUG-891 inhibits neuronal endoplasmic reticulum stress and pyroptosis activation and protects neurons in a mouse model of intraventricular hemorrhage

Pyroptosis plays an important role in hemorrhagic stroke.Excessive endoplasmic reticulum stress can cause endoplasmic reticulum dysfunction and cellular pyroptosis by regulating the nucleotide-binding oligomerization domain and leucine-rich repeat pyrin domain-containing protein 3(NLRP3)pathway.However,the relationship between pyroptosis and endoplasmic reticulum stress after intraventricular hemorrhage is unclear.In this study,we established a mouse model of intraventricular hemorrhage and found pyroptosis and endoplasmic reticulum stress in brain tissue.Intraperitoneal injection of the selective GPR120 agonist TUG-891 inhibited endoplasmic reticulum stress,pyroptosis,and inflammation and protected neurons.The neuroprotective effect of TUG-891 appears related to inhibition of endoplasmic reticulum stress and pyroptosis activation.

CPAL, as a New Mediator of Cardiomyocyte Metabolic Alterations and Pyroptosis, Regulates Myocardial Infarction Injury in Mice

Myocardial infarction (MI), the most serious of the ischemic heart diseases, is accompanied by myocardial metabolic disorders and the loss of cardiomyocytes. Increasing evidence has shown that long noncoding RNAs (lncRNAs) are involved in various pathological conditions such as cancer and cardiovascular diseases (CVDs), and are emerging as a novel biomarker for these disorders. This study aims to investigate the regulatory role and mechanisms of lncRNAs in myocardial remodeling in the setting of MI. We find that post-infarcted hearts exhibit a reduction of adenosine triphosphate (ATP) and an alteration of the glucose and lipid metabolism genes cluster of differentiation 36 (CD36), hexokinase 1 (HK1), and clucose transporter 4 (GLUT4), accompanied by cardiomyocyte pyroptosis. We then identify a previously unknown conserved lncRNA, AK009126 (cardiomyocyte pyroptosis-associated lncRNA, CPAL), which is remarkably upregulated in the myocardial border zone of MI mice. Importantly, the adeno-associated virus 9 (AAV9)-mediated silencing of endogenous CPAL by its short hairpin RNA (shRNA) partially abrogates myocardial metabolic alterations and cardiomyocyte pyroptosis during MI in mice. Mechanistically, CPAL is shown to bind directly to nuclear factor kappa B (NFκB) and to act as an activator of NFκB to induce NFκB phosphorylation in cardiomyocytes. We also find that CPAL upregulates caspase-1 expression at the transcriptional level and consequently promotes the release of interleukin (IL)-18 and IL-1β from cardiomyocytes. Collectively, our findings reveal the conserved lncRNA CPAL as a new regulator of cardiac metabolic abnormalities and cardiomyocyte pyroptosis in the setting of MI and suggest CPAL as a new therapeutic target to protect cardiomyocytes against ischemic injury in infarcted hearts.

Propionate and butyrate attenuate macrophage pyroptosis and osteoclastogenesis induced by CoCrMo alloy particles

Background:Wear particles-induced osteolysis is a major long-term complication after total joint arthroplasty.Up to now,there is no effective treatment for wear particles-induced osteolysis except for the revision surgery,which is a heavy psychological and economic burden to patients.A metabolite of gut microbiota,short chain fatty acids(SCFAs),has been reported to be beneficial for many chronic inflammatory diseases.This study aimed to investigate the therapeutic effect of SCFAs on osteolysis.Methods:A model of inflammatory osteolysis was established by applying CoCrMo alloy particles to mouse calvarium.After two weeks of intervention,the anti-inflammatory effects of SCFAs on wear particle-induced osteolysis were evaluated by micro-CT analysis and immunohistochemistry staining.In vitro study,lipopolysaccharide(LPS)primed bone marrow-derived macrophages(BMDMs)and Tohoku hospital pediatrics-1(THP-1)macrophages were stimulated with CoCrMo particles to activate inflammasome in the presence of acetate(C2),propionate(C3),and butyrate(C4).Western blotting,enzyme-linked immunosorbent assay,and immunofluorescence were used to detect the activation of NLRP3 inflammasome.The effects of SCFAs on osteoclasts were evaluate by qRT-PCR,Western blotting,immunofluorescence,and tartrate-resistant acid phosphatase(TRAP)staining.Additionally,histone deacetylase(HDAC)inhibitors,agonists of GPR41,GPR43,and GPR109A were applied to confirm the underlying mechanism of SCFAs on the inflammasome activation of macrophages and osteoclastogenesis.Results:C3 and C4 but not C2 could alleviate wear particles-induced osteolysis with fewer bone erosion pits(P<0.001),higher level of bone volume to tissue volume(BV/TV,P<0.001),bone mineral density(BMD,P<0.001),and a lower total porosity(P<0.001).C3 and C4 prevented CoCrMo alloy particles-induced ASC speck formation and nucleationinduced oligomerization,suppressing the cleavage of caspase-1(P<0.05)and IL-1β(P<0.05)stimulated by CoCrMo alloy particles.C3 and C4 also inhibited the generation of gasdermin D-N-terminal fragment(GSDMD-NT)to regulate pyroptosis.Besides,C3 and C4 have a negative impact on osteoclast differentiation(P<0.05)and its function(P<0.05),affecting the podosome arrangement and morphologically normal podosome belts formation.Conclusions:Our work showed that C3 and C4 are qualified candidates for the treatment of wear particle-induced osteolysis.