Lactobacillus plantarum J26 alleviates alcohol-induced oxidative liver injury by regulating the Nrf2 signaling pathway

Oxidative stress is one of the main ways to cause alcohol-induced liver injury,and alcoholic liver disease(ALD)has been a common health problem worldwide.Lactic acid bacteria(LAB)is also considered as a potential treatment to alleviate alcohol-induced liver injury.Lactobacillus plantarum J26 is a LAB isolated from Chinese traditional fermented dairy products with excellent probiotic effects.This study aimed to establish a mice model of alcoholic liver injury through acute-on-chronic alcohol feeding and to study the alleviating effect of pre-intake of L.plantarum J26 on alcohol-induced oxidative liver injury and focus on its potential mechanism of alleviating effect.The results showed that pre-intake of L.plantarum J26 could improve liver pathological changes,reduce lipid accumulation,increase mitochondrial ATP and mitochondrial(mtDNA)levels,and alleviate liver injury.In addition,pre-intake L.plantarum J26 can improve the level of short-chain fatty acids(SCFAs)in the intestines in mice,short chain fatty acids can be used as a signaling molecule activation of nuclear factor E2-related factor 2(Nrf2)signaling pathway to alleviate liver oxidative stress,and maintain mitochondrial homeostasis by regulating the expression of genes related to mitochondrial dynamics and autophagy,thereby reducing cell apoptosis to alleviate alcohol-induced oxidative liver injury.

Procyanidin A_1 and its digestive products alleviate acrylamide-induced IPEC-J2 cell damage through regulating Keap1/Nrf2 pathway

Our previous study has revealed that procyanidin A_(1)(A_(1))and its simulated digestive product(D-A,)can alleviate acrylamide(ACR)-induced intestine cell damage.However,the underlying mechanism remains unknown.In this study,we elucidated the molecular mechanism for and D-A_(1) to alleviate ACR-stimulated IPEC-J2 cell damage.ACR slightly activated nuclear factor erythroid 2-related factor 2(Nrf2)signaling and its target genes,but this activation could not reduce intestine cell damage.A_(1) and D-A_(1) could alleviate ACR-induced cell damage,but the effect was abrogated in cells transiently transfected with Nrf2 small interfering RNA(siRNA).Further investigation confirmed that A_(1) and D-A_(1) interacted with Ketch-like ECH-associated protein 1(Keapl),which boosted the stabilization of Nrf2,subsequently promoted the translocation of Nrf2 into the nucleus,and further increased the expression of antioxidant proteins,thereby inhibiting glutathione(GSH)consumption,maintaining redox balance and eventually alleviating ACR-induced cell damage.Importantly,there was no difference between A_(1) and D-A_(1) treated groups,indicating that A_(1) can tolerate gastrointestinal digestion and may be a potential compound to limit the toxicity of ACR.

High glucose reduces Nrf2-dependent cRAGE release and enhances inflammasome-dependent IL-1βproduction in monocytes:the modulatory effects of EGCG

Soluble receptor for advanced glycation end products(sRAGE)acts as a decoy sequestering of RAGE ligands,thus preventing the activation of the ligand-RAGE axis linking human diseases.However,the molecular mechanisms underlying sRAGE remain unclear.In this study,THP-1 monocytes were cultured in normal glucose(NG,5.5 mmol/L)and high glucose(HG,15 mmol/L)to investigate the effects of diabetesrelevant glucose concentrations on sRAGE and interleukin-1β(IL-1β)secretion.The modulatory effects of epigallocatechin gallate(EGCG)in response to HG challenge were also evaluated.HG enhanced intracellular reactive oxygen species(ROS)generation and RAGE expression.The secretion of sRAGE,including esRAGE and cRAGE,was reduced under HG conditions,together with the downregulation of a disintegrin and metallopeptidase 10(ADAM10)and nuclear factor erythroid 2-related factor 2(Nrf2)nuclear translocation.Mechanistically,the HG effects were counteracted by siRAGE and exacerbated by siNrf2.Chromatin immunoprecipitation results showed that Nrf2 binding to the ADAM10 promoter and HG interfered with this binding.Our data reinforce the notion that RAGE and Nrf2 might be sRAGE-regulating factors.Under HG conditions,the treatment of EGCG reduced ROS generation and RAGE activation.EGCG-stimulated cRAGE release was likely caused by the upregulation of the Nrf2-ADAM10 pathway.EGCG inhibited HG-mediated NLRP3 inflammasome activation at least partly by stimulating sRAGE,thereby reducing IL-1βrelease.

The therapeutic mechanism of Polygonatum sibiricum polysaccharide on T2DM rats based on the Nrf2 signaling pathway

Background:This study will be aimed at investigating the effects of Polygonatum sibiricum polysaccharide(PSP)in a rat model of type 2 diabetes mellitus(T2DM).Methods:Thirty Sprague–Dawley male rats were evenly distributed into three groups:normal,T2DM,and PSP groups,by applying a random sample table method.The typical cluster was served balanced food every day,whereas the others were supplied with a high-fat diet and streptozotocin injections to make T2DM rat models.The changes in humor organic chemistry indicators and liver histopathology were determined following the model institution for every cluster.After PSP intervention,western blotting was applied to research the expression levels of crucial transcription factors concerned within the nuclear factor erythroid 2-related factor 2(Nrf2)signal pathway,as well as Nrf2,glutamate-cysteine ligase chemical process fractional monetary unit,NQO1 and HO-1 within the liver tissues of the rat models,and to seem into the therapeutic edges of PSP and the way it happens in T2DM rats.Results:PSP intervention considerably reduced the concentration levels of aldohexose,lipids,liver-operated indicators,and alternative organic chemistry indicators within the humor of T2DM rat models and improved the histopathological changes within the liver.In addition,the activity of SOD and GSH-Px were increased,and the levels of MDA were decreased in the liver tissues of T2DM rat models following PSP intervention.Western blotting revealed that the expression levels of the Nrf2,HO-1,glutamate-cysteine ligase chemical,and NQO1 proteins were increased in rat liver tissues following PSP intervention.Conclusion:PSP has therapeutic effects in T2DM rat models,and its mechanism of motion might also be related to regulating the Nrf2 signaling pathway in liver tissues and alleviating oxidative stress.

20C,a new bibenzyl compound,plays a significant role in rotenone-induced oxidative insult

20C,a bibenzyl compound isolated from Gastrodia elata,possesses antioxidative properties in PC12 cells,but its in-depth molecular mechanisms against rotenone-induced neurotoxicity remains unknown.Recent studies indicate that without intact DJ-1,nuclear factor erythroid 2-related factor(Nrf2)protein becomes unstable,and the activity of Nrf2-mediated downstream antioxidant enzymes are thereby suppressed.Therefore,increasing the nuclear translocation of Nrf2 by DJ-1 may present a helpful means for the prevention and treatment of chronic diseases related to oxidative stress.Our results showed that 20C clearly protected PC12 and SH-SY5Y cells against rotenone-induced oxidative injury in a concentration-dependent manner.Furthermore,20C markedly up-regulated the levels of DJ-1,which in turn activated phosphoinositide-3-kinase(PI3K)/Akt signaling and inhibited glycogen synthase kinase 3β(GSK3β)activation,eventually promoting Nrf2 nuclear translocation and inducing the expression of Nrf2-mediated downstream antioxidative enzymes such as HO-1.The antioxidative effects of 20C could be partially blocked by ShR NA-mediated knockdown of DJ-1 and inhibition of the PI3K/Akt pathways with Akt1/2 kinase inhibitor in PC12 and SH-SY5Y cells,respectively.Conclusively,our findings confirm that DJ-1 is necessary for 20C-mediated protection against rotenone-induced oxidative damage,at least in part,by activating PI3K/Akt signaling,and subsequently enhancing the nuclear accumulation of Nrf2.The findings from our investigation suggest that 20C should be developed as a novel candidate for preventing or alleviating the consequences of PD in the future.

Engineered Bacillus subtilis alleviates intestinal oxidative injury through Nrf2-Keap1 pathway in enterotoxigenic Escherichia coli(ETEC) K88-infected piglet

Engineered probiotics can serve as therapeutics based on their ability of produce recombinant immune-stimulating properties.In this study,we built the recombinant Bacillus subtilis WB800 expressing antimicrobial peptide KR32(WB800-KR32)using genetic engineering methods and investigated its protective effects of nuclear factor-E2-related factor 2(Nrf2)-Kelch-like ECH-associated protein 1(Keap1)pathway activation in intestinal oxidative disturbance induced by enterotoxigenic Escherichia coli(ETEC)K88 in weaned piglets.Twenty-eight weaned piglets were randomly distributed into four treatment groups with seven replicates fed with a basal diet.The feed of the control group(CON)was infused with normal sterilized saline;meanwhile,the ETEC,ETEC+WB800,and ETEC+WB800-KR32 groups were orally administered normal sterilized saline,5×10^(10)CFU(CFU:colony forming units)WB800,and 5×10^(10)CFU WB800-KR32,respectively,on Days 1-14 and all infused with ETEC K881×10^(10)CFU on Days 15-17.The results showed that pretreatment with WB800-KR32 attenuated ETEC-induced intestinal disturbance,improved the mucosal activity of antioxidant enzyme(catalase(CAT),superoxide dismutase(SOD),and glutathione peroxidase(GPx))and decreased the content of malondialdehyde(MDA).More importantly,WB800-KR32 downregulated genes involved in antioxidant defense(GPx and SOD1).Interestingly,WB800-KR32 upregulated the protein expression of Nrf2 and downregulated the protein expression of Keap1 in the ileum.WB800-KR32 markedly changed the richness estimators(Ace and Chao)of gut microbiota and increased the abundance of Eubacterium_rectale_ATCC_33656 in the feces.The results suggested that WB800-KR32 may alleviate ETEC-induced intestinal oxidative injury through the Nrf2-Keap1 pathway,providing a new perspective for WB800-KR32 as potential therapeutics to regulate intestinal oxidative disturbance in ETEC K88 infection.

白花丹素调控Nrf-2/Keap1信号通路诱导膀胱癌细胞铁死亡

目的:探讨白花丹素作为一种新型的铁死亡诱导剂在膀胱癌抑制中的作用机制。方法:本研究中使用了膀胱癌细胞T24。采用细胞增殖与活性检测-8(CCK-8)法检测白花丹素(0.1、1、2、3、6、12、24、48μmol·L^(-1))对T24细胞活力的影响。采用膜联蛋白V-异硫氰酸荧光素/碘化丙啶(Annexin V FITC/PI)凋亡试剂盒检测白花丹素(1.5、3、6μmol·L^(-1))对T24细胞凋亡的影响。采用不同的抑制剂(铁死亡抑制剂Fer-1,凋亡抑制剂VAD,坏死性凋亡抑制剂Nec-1)与白花丹素(6μmol·L^(-1))联合使用。采用活性氧荧光探针(DCFH-DA),丙二醛(MDA)和谷胱甘肽(GSH)试剂盒分别检测不同浓度的白花丹素(1.5、3、6μmol·L^(-1))对T24细胞内活性氧水平,MDA和GSH的含量,脂质过氧化荧光探针(C11-BODIPY)荧光探针检测白花丹素(1.5、3、6μmol·L^(-1))对T24细胞中过氧化物水平的影响。蛋白免疫印迹法(Western blot)检测白花丹素(1.5、3、6μmol·L^(-1))细胞中溶质载体家族7成员11(SLC7A11)、谷胱甘肽过氧化酶(GPX4)、核因子E2相关因子-2(Nrf-2)和Kelch样ECH关联蛋白1(Keap1)的蛋白表达的影响。结果:与空白组比较,白花丹素组T24细胞的活性明显降低(P<0.05),IC50为3.52μmol·L^(-1)。与空白组比较,白花丹素组(1.5、3、6μmol·L^(-1))T24细胞凋亡率明显升高(P<0.05);与单独使用6μmol·L^(-1)的白花丹素组比较,铁死亡抑制剂和凋亡抑制剂组能够逆转6μmol·L^(-1)的白花丹素对T24细胞增殖抑制作用(P<0.05)。与空白组比较,白花丹素组(1.5、3、6μmol·L^(-1)),T24细胞ROS、MDA及脂质过氧化物的含量明显升高,GSH水平明显降低,铁死亡相关蛋白SLC7A11、GPX4以及Nrf-2/Keap1明显降低(P<0.05)。结论:白花丹素能诱导细胞铁死亡,其机制与Nrf-2/Keap1信号通路有关。

Biological insights in non-small cell lung cancer

Lung oncogenesis relies on intracellular cysteine to overcome oxidative stress.Several tumor types,including non-small cell lung cancer(NSCLC),upregulate the system x-c cystine/glutamate antiporter(xCT)through overexpression of the cystine transporter SLC7A11,thus sustaining intracellular cysteine levels to support glutathione synthesis.Nuclear factor erythroid 2-related factor 2(NRF2)serves as a master regulator of oxidative stress resistance by regulating SLC7A11,whereas Kelch-like ECH-associated protein(KEAP1)acts as a cytoplasmic repressor of the oxidative responsive transcription factor NRF2.Mutations in KEAP1/NRF2 and p53 induce SLC7A11 activation in NSCLC.Extracellular cystine is crucial in supplying the intracellular cysteine levels necessary to combat oxidative stress.Disruptions in cystine availability lead to iron-dependent lipid peroxidation,thus resulting in a type of cell death called ferroptosis.Pharmacologic inhibitors of xCT(either SLC7A11 or GPX4)induce ferroptosis of NSCLC cells and other tumor types.When cystine uptake is impaired,the intracellular cysteine pool can be sustained by the transsulfuration pathway,which is catalyzed by cystathionine-B-synthase(CBS)and cystathionine g-lyase(CSE).The involvement of exogenous cysteine/cystine and the transsulfuration pathway in the cysteine pool and downstream metabolites results in compromised CD8^(+)T cell function and evasion of immunotherapy,diminishing immune response and potentially reducing the effectiveness of immunotherapeutic interventions.Pyroptosis is a previously unrecognized form of regulated cell death.In NSCLCs driven by EGFR,ALK,or KRAS,selective inhibitors induce pyroptotic cell death as well as apoptosis.After targeted therapy,the mitochondrial intrinsic apoptotic pathway is activated,thus leading to the cleavage and activation of caspase-3.Consequently,gasdermin E is activated,thus leading to permeabilization of the cytoplasmic membrane and cell-lytic pyroptosis(indicated by characteristic cell membrane ballooning).Breakthroughs in KRAS G12C allele-specific inhibitors and potential mechanisms of resistance are also discussed herein.

Nrf2-mediated ferroptosis of spermatogenic cells involved in male reproductive toxicity induced by polystyrene nanoplastics in mice

Microplastics(MPs)and nanoplastics(NPs)have become hazardous materials due to the massive amount of plastic waste and disposable masks,but their specific health effects remain uncertain.In this study,fluorescence-labeled polystyrene NPs(PS-NPs)were injected into the circulatory systems of mice to determine the distribution and potential toxic effects of NPs in vivo.Interestingly,whole-body imaging found that PS-NPs accumulated in the testes of mice.Therefore,the toxic effects of PS-NPs on the reproduction systems and the spermatocytes cell line of male mice,and their mechanisms,were investigated.After oral exposure to PS-NPs,their spermatogenesis was affected and the spermatogenic cells were damaged.The spermatocyte cell line GC-2 was exposed to PS-NPs and analyzed using RNA sequencing(RNA-seq)to determine the toxic mechanisms;a ferroptosis pathway was found after PS-NP exposure.The phenomena and indicators of ferroptosis were then determined and verified by ferroptosis inhibitor ferrostatin-1(Fer-1),and it was also found that nuclear factor erythroid 2-related factor 2(Nrf2)played an important role in spermatogenic cell ferroptosis induced by PS-NPs.Finally,it was confirmed in vivo that this mechanism of Nrf2 played a protective role in PS-NPs-induced male reproductive toxicity.This study demonstrated that PS-NPs induce male reproductive dysfunction in mice by causing spermatogenic cell ferroptosis dependent on Nrf2.

Pre-treatment twice with liposomal clodronate protects against acetaminophen hepatotoxicity through a pre-conditioning effect

Background and aim:Acetaminophen(APAP)overdose is a major cause of acute liver injury,but the role of macrophages in the propagation of the hepatotoxicity is controversial.Early research revealed that macrophage inhibitors protect against APAP injury.However,later work demonstrated that macrophage ablation by acute pre-treatment with liposomal clodronate(LC)exacerbates the toxicity.To our surprise,during other studies,we observed that pre-treatment twice with LC seemed to protect against APAP hepatotoxicity,in contrast to acute pre-treatment.The aim of this study was to confirm that observation and to explore the mechanisms.Methods:We treated mice with empty liposomes(LE)or LC twice per week for 1 week before APAP overdose and collected blood and liver tissue at 0,2,and 6 h post-APAP.We then measured liver injury(serum alanine aminotransferase activity,histology),APAP bioactivation(total glutathione,APAP-protein adducts),oxidative stress(oxidized glutathione(GSSG)),glutamate-cysteine ligase subunit c(Gclc)mRNA,and nuclear factor erythroid 2-related factor(Nrf2)immunofluorescence.We also confirmed the ablation of macrophages by F4/80 immunohistochemistry.Results:Pre-treatment twice with LC dramatically reduced F4/80 staining,protected against liver injury,and reduced oxidative stress at 6 h post-APAP,without affecting APAP bioactivation.Importantly,Gclc mRNA was higher in the LC group at 0 h and total glutathione was higher at 2 h,indicating accelerated glutathione re-synthesis after APAP overdose due to greater basal glutamate-cysteine ligase.Oxidative stress was lower in the LC groups at both time points.Finally,total Nrf2 immunofluorescence was higher in the LC group.Conclusions:We conclude that multiple pre-treatments with LC protect against APAP by accelerating glutathione re-synthesis through glutamate-cysteine ligase.Investigators using twice or possibly more LC pre-treatments to deplete macrophages,including peritoneal macrophages,should be aware of this possible confounder.