Targeting nuclear factor erythroid 2-related factor 2-regulated ferroptosis to treat nervous system diseases

By critically examining the work,we conducted a comprehensive bibliometric analysis on the role of nuclear factor erythroid 2-related factor 2(NRF2)in nervous system diseases.We also proposed suggestions for future bibliometric studies,including the integration of multiple websites,analytical tools,and analytical approaches,The findings presented provide compelling evidence that ferroptosis is closely associated with the therapeutic challenges of nervous system diseases.Targeted modulation of NRF2 to regulate ferroptosis holds substantial potential for effectively treating these diseases.Future NRF2-related research should not only focus on discovering new drugs but also on designing rational drug delivery systems.In particular,nanocarriers offer substantial potential for facilitating the clinical translation of NRF2 research and addressing existing issues related to NRF2-related drugs.

Emerging trends and hotspots of Nuclear factor erythroid 2-related factor 2 in nervous system diseases

BACKGROUND The Nuclear factor erythroid 2-related factor 2(NRF2)transcription factor has attracted much attention in the context of neurological diseases.However,none of the studies have systematically clarified this field's research hotspots and evolution rules.AIM To investigate the research hotspots,evolution patterns,and future research trends in this field in recent years.METHODS We conducted a comprehensive literature search in the Web of Science Core Collection database using the following methods:(((((TS=(NFE2 L2))OR TS=(Nfe2 L2 protein,mouse))OR TS=(NF-E2-Related Factor 2))OR TS=(NRF2))OR TS=(NFE2L2))OR TS=(Nuclear factor erythroid2-related factor 2)AND(((((((TS=(neurological diseases))OR TS=(neurological disorder))OR TS=(brain disorder))OR TS=(brain injury))OR TS=(central nervous system disease))OR TS=(CNS disease))OR TS=(central nervous system disorder))OR TS=(CNS disorder)AND Language=English from 2010 to 2022.There are just two forms of literature available:Articles and reviews.Data were processed with the software Cite-Space(version 6.1.R6).RESULTS We analyzed 1884 articles from 200 schools in 72 countries/regions.Since 2015,the number of publications in this field has increased rapidly.China has the largest number of publications,but the articles published in the United States have better centrality and H-index.Among the top ten authors with the most published papers,five of them are from China,and the author with the most published papers is Wang Handong.The institution with the most articles was Nanjing University.To their credit,three of the top 10 most cited articles were written by Chinese scholars.The keyword co-occurrence map showed that"oxidative stress","NRF2","activation","expression"and"brain"were the five most frequently used keywords.CONCLUSION Research on the role of NRF2 in neurological diseases continues unabated.Researchers in developed countries published more influential papers,while Chinese scholars provided the largest number of articles.There have been numerous studies on the mechanism of NRF2 transcription factor in neurological diseases.NRF2 is also emerging as a potentially effective target for the treatment of neurological diseases.However,despite decades of research,our knowledge of NRF2 transcription factor in nervous system diseases is still limited.Further studies are needed in the future.

Neuroprotective effects of salidroside on focal cerebral ischemia/reperfusion injury involve the nuclear erythroid 2-related factor 2 pathway

Salidroside,the main active ingredient extracted from Rhodiola crenulata,has been shown to be neuroprotective in ischemic cerebral injury,but the underlying mechanism for this neuroprotection is poorly understood.In the current study,the neuroprotective effect of salidroside on cerebral ischemia-induced oxidative stress and the role of the nuclear factor erythroid 2-related factor 2（Nrf2）pathway was investigated in a rat model of middle cerebral artery occlusion.Salidroside（30 mg/kg）reduced infarct size,improved neurological function and histological changes,increased activity of superoxide dismutase and glutathione-S-transferase,and reduced malon-dialdehyde levels after cerebral ischemia and reperfusion.Furthermore,salidroside apparently increased Nrf2 and heme oxygenase-1 expression.These results suggest that salidroside exerts its neuroprotective effect against cerebral ischemia through anti-oxidant mechanisms and that activation of the Nrf2 pathway is involved.The Nrf2/antioxidant response element pathway may become a new therapeutic target for the treatment of ischemic stroke.

Interplay between nuclear factor erythroid 2-related factor 2 and inflammatory mediators in COVID-19-related liver injury

Coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2 is a global pandemic and poses a major threat to human health worldwide.In addition to respiratory symptoms,COVID-19 is usually accompanied by systemic inflammation and liver damage in moderate and severe cases.Nuclear factor erythroid 2-related factor 2(NRF2)is a transcription factor that regulates the expression of antioxidant proteins,participating in COVID-19-mediated inflammation and liver injury.Here,we show the novel reciprocal regulation between NRF2 and inflammatory mediators associated with COVID-19-related liver injury.Additionally,we describe some mechanisms and treatment strategies.

Nuclear factor erythroid 2-related factor 2-mediated signaling and metabolic associated fatty liver disease

Oxidative stress is a key driver in the development and progression of several diseases,including metabolic associated fatty liver disease(MAFLD).This condition includes a wide spectrum of pathological injuries,extending from simple steatosis to inflammation,fibrosis,cirrhosis,and hepatocellular carcinoma.Excessive buildup of lipids in the liver is strictly related to oxidative stress in MAFLD,progressing to liver fibrosis and cirrhosis.The nuclear factor erythroid 2-related factor 2(NRF2)is a master regulator of redox homeostasis.NRF2 plays an important role for cellular protection by inducing the expression of genes related to antioxidant,anti-inflammatory,and cytoprotective response.Consistent evidence demonstrates that NRF2 is involved in every step of MAFLD development,from simple steatosis to inflammation,advanced fibrosis,and initiation/progression of hepatocellular carcinoma.NRF2 activators regulate lipid metabolism and oxidative stress alleviating the fatty liver disease by inducing the expression of cytoprotective genes.Thus,modulating NRF2 activation is crucial not only in understanding specific mechanisms underlying MAFLD progression but also to characterize effective therapeutic strategies.This review outlined the current knowledge on the effects of NRF2 pathway,modulators,and mechanisms involved in the therapeutic implications of liver steatosis,inflammation,and fibrosis in MAFLD.

Keap1-nuclear factor rythroid 2-related factor 2 inhibitor NXPZ ameliorates Aβ1-42-induced cognitive dysfunction in mice

OBJECTIVE Nuclear factor erythroid 2-related factor 2(Nrf2) is found to be ubiquitiously expressed in many tissues,and works as the key regulator against oxidative stress damage in cells and organs,which makes Nrf2 a widely concerned drug target.Recent research has identified that Nrf2 is involved in the pathology of Alzheimer disease(AD),whereas the mechanism is unknown.The purpose of this study is to figure out the role of Nrf2 in the pathologic process of AD through Nrf2-Keap1-ARE pathway and the effects of Keap1-Nrf2 inhibitor in AD mice models.METHODS Amyloid β^(1-42)(Aβ^(1-42))was injected into the bilateral hippocampus to induce the cognitive dysfunction in eight-week old male mice.The mice were treated with Keap1-Nrf2 inhibitor NXPZ of three doses as well as donepezil as a positive control by intragastric administration one time a day for one week.Several behavior tests were used to analyze the mice learning and memory ability.Additionally,we detected Nrf2 and Aβ in the plasma in mice with ELISA kits,as well as some factors related to oxidative stress in the hippocampus and cortex.The expression levels of Nrf2,Keap1,Tau and p-Tau were measured in the murine brain tissue with Western blotting.SH-SY5 Y cells were studied as an in vitro model to further clarify the mechanism.RESULTS The treatment of NXPZ ameliorated learning and memory dysfunction in AD mice in a dose-dependent manner,and the high dose group recovered better than the positive drug group.The plasma Nrf2 level was increased in a dose-dependent manner in the treatment groups;however,the plasma Aβ was decreased.What′ s more,superoxide dismutase(SOD) and glutathione reductase(GSSH) in the hippocampus and cortex were increased in the treatment group,while the malondialdehyde(MDA) was decreased,meaning that NXPZ treatment promoted expression of the anti-oxidative factors and inhibited the expression of the oxidative factors in the down-stream.Western blotting analysis of hippocampus and cortex showed up-regulated Nrf2,decreased Keap1 and decreased p-Tau in NXPZ treatment mice.In ex vivo experiments,when SH-SY5 Y cells were treated with Aβ,Nrf2 in the cytoplasm was increased,as well as the expression Nrf2 in the nuclear was decreased.The treatment of NXPZ increased nuclear Nrf2,decreased cytoplasm Nrf2,and decreased the expression of p-Tau.CONCLUSION Nrf2 has an important role in neuron function.Nrf2 activation by selective Keap1-Nrf2 inhibitor NXPZ may contribute to improve cognitive function in AD mice.The mechanism may be related to increased generation and release of Nrf2 induced by more disaggregation with Keap1,leading to more expression of anti-oxidative molecules to protect the damage caused by Aβ.These results indicates that Nrf2 may be a novel therapeutic target of AD and Keap1-Nrf2 inhibitor may be a novel medication for protecting the loss of learning and memory ability.

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.

Hydrogen sulfide reduces oxidative stress in Huntington's disease via Nrf2

The pathophysiology of Huntington's disease involves high levels of the neurotoxin quinolinic acid. Quinolinic acid accumulation results in oxidative stress, which leads to neurotoxicity. However, the molecular and cellular mechanisms by which quinolinic acid contributes to Huntington's disease pathology remain unknown. In this study, we established in vitro and in vivo models of Huntington's disease by administering quinolinic acid to the PC12 neuronal cell line and the striatum of mice, respectively. We observed a decrease in the levels of hydrogen sulfide in both PC12 cells and mouse serum, which was accompanied by down-regulation of cystathionine β-synthase, an enzyme responsible for hydrogen sulfide production. However, treatment with NaHS(a hydrogen sulfide donor) increased hydrogen sulfide levels in the neurons and in mouse serum, as well as cystathionine β-synthase expression in the neurons and the mouse striatum, while also improving oxidative imbalance and mitochondrial dysfunction in PC12 cells and the mouse striatum. These beneficial effects correlated with upregulation of nuclear factor erythroid 2-related factor 2 expression. Finally, treatment with the nuclear factor erythroid 2-related factor 2inhibitor ML385 reversed the beneficial impact of exogenous hydrogen sulfide on quinolinic acid-induced oxidative stress. Taken together, our findings show that hydrogen sulfide reduces oxidative stress in Huntington's disease by activating nuclear factor erythroid 2-related factor 2,suggesting that hydrogen sulfide is a novel neuroprotective drug candidate for treating patients with Huntington's disease.

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.

Etomidate protects retinal ganglion cells from hydrogen peroxide-induced injury via Nrf2/HO-1 pathway

AIM:To determine whether etomidate(ET)has a protective effect on retinal ganglion cells(RGCs)injured with hydrogen peroxide(H_(2)O_(2))and to explore the potential mechanism underlying the antioxidative stress effect of ET.METHODS:Cultured RGCs were identified by double immunofluorescent labeling of microtubule-associated protein 2 and Thy1.1.An injury model of H_(2)O_(2)-induced RGCs oxidative stress was established in vitro.Cells were pretreated with different concentrations of ET(1,5,and 10μmol/L)for 4h,followed by further exposure to H_(2)O_(2)at 1000μmol/L.Cell counting kit 8 and Annexin V/propidium iodide assays were applied to detect the viabilities and apoptosis rates of the RGCs at 12,24,and 48h after H_(2)O_(2)stimulation.The levels of nitric oxide,malondialdehyde,and glutathione in culture media were measured at these time points.Quantitative reverse transcription polymerase chain reaction(qRT-PCR)and Western blot were performed to observe the effects of ET on the messenger RNA and protein expression of inducible nitric oxide synthase(iNOS),nuclear factor erythroid 2-related factor 2(Nrf2),heme oxygenase 1(HO-1),glutathione peroxidase 1 and the level of conjugated acrolein in RGCs at 12,24,and 48h after H_(2)O_(2)stimulation and in the retina at 12h after optic nerve transection(ONT).RESULTS:The applications of 5 and 10μmol/L of ET significantly increased the viability of RGCs.Results from qRT-PCR indicated a decrease in the expression of iNOS and an increase in the expressions of Nrf2 and HO-1 in ETpretreated RGCs at 12,24 and 48h after H_(2)O_(2)stimulation,as well as in ET-treated retinas at 12h after ONT.Western blot analysis revealed a decrease in the expression of iNOS and levels of conjugated acrolein,along with an increase in the expressions of Nrf2 and HO-1 in ET-pretreated RGCs in vitro and ET-treated retinas in vivo.CONCLUSION:ET is a neuroprotective agent in primary cultured RGCs injured by H_(2)O_(2).The effect of ET is dosedependent with the greatest effect being at 10μmol/L.ET plays an antioxidant role by inhibiting iNOS,up-regulating Nrf2/HO-1,decreasing the production of acrolein,and increasing the scavenge of acrolein.

Functionalized selenium nanoparticles ameliorated acetaminophen-induced hepatotoxicity through synergistically triggering PKCδ/Nrf2 signaling pathway and inhibiting CYP 2E1

Selenium nanoparticles(SeNPs)have been demonstrated potential for use in diseases associated with oxidative stress.Functionalized SeNPs with lower toxicity and higher biocompatibility could bring better therapeutic activity and clinical application value.Herein,this work was conducted to investigate the protective effect of Pleurotus tuber-regium polysaccharide-protein complex funtionnalized SeNPs(PTR-SeNPs)against acetaminophen(APAP)-induced oxidative injure in HepG2 cells and C57BL/6J mouse liver.Further elucidation of the underlying molecular mechanism,in particular their modulation of Nrf2 signaling pathway was also performed.The results showed that PTR-SeNPs could significantly ameliorate APAP-induced oxidative injury as evidenced by a range of biochemical analysis,histopathological examination and immunoblotting study.PTR-SeNPs could hosphorylate and activate PKCδ,depress Keap1,and increase nuclear accumulation of Nrf2,resulting in upregulation of GCLC,GCLM,HO-1 and NQO-1 expression.Besides,PTR-SeNPs suppressed the biotransformation of APAP to generate intracellular ROS through CYP 2E1 inhibition,restoring the mitochondrial morphology.Furthermore,the protective effect of PTR-SeNPs against APAP induced hepatotoxicity was weakened as Nrf2 was depleted in vivo,indicating the pivotal role of Nrf2 signaling pathway in PTR-SeNPs mediated hepatoprotective efficacy.Being a potential hepatic protectant,PTR-SeNPs could serve as a new source of selenium supplement for health-promoting and biomedical applications.

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.

Targeting Nrf2 signaling in dry eye

Dry eye,the most common ocular surface disease,can cause ocular surface tissue damage and discomfort symptoms and seriously affect people’s quality of life.The etiology of dry eye is diverse,and its pathogenesis is complex.The oxidative stress reaction is considered to be among the important factors in the pathogenesis of dry eye.Therefore,activating the antioxidant system has a potential therapeutic effect on dry eye.Nuclear factor erythroid 2-related factor 2(Nrf2)signaling pathway is considered the most important antioxidant pathway in the body.The activation of the Nrf2 signaling pathway and its interaction with other pathways are important mechanisms to prevent the occurrence and development of dry eye.This review describes the structure and function of Nrf2,summarizes the changes in the oxidative stress response in dry eye,focuses on the potential mechanism of the Nrf2 signaling pathway in the treatment of dry eye,and,finally,summarizes the drugs that activate the Nrf2 signaling pathway in the treatment of dry eye.

橙皮素调控Nrf2/ARE通路改善载脂蛋白E基因敲除小鼠动脉粥样硬化的实验研究

目的:基于核因子E2相关因子2(Nrf2)/抗氧化反应原件(ARE)通路探讨橙皮素对载脂蛋白E基因敲除(ApoE^(-/-))小鼠动脉粥样硬化(AS)的影响。方法:将48只ApoE^(-/-)小鼠用高脂饮食喂养12周后,采用左颈总动脉缩窄性套管法建立ApoE^(-/-)小鼠AS模型。模型制备成功后将ApoE^(-/-)小鼠随机分为模型组、橙皮素低剂量组、橙皮素高剂量组、鸦胆子苦醇组,每组12只。另取12只雄性C57BL/6J小鼠作为对照组,给予普通饲料喂养。橙皮素低、高剂量组小鼠分别给予50 mg/kg、100 mg/kg橙皮素灌胃,每日1次;鸦胆子苦醇组小鼠灌胃100 mg/kg橙皮素,隔天腹腔注射Nrf2抑制剂鸦胆子苦醇2 mg/kg,连续给药12周;对照组和模型组给予等量0.5%羧甲基纤维素钠灌胃。检测各组血清血脂水平以及丙二醛(MDA)、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)水平;油红O染色观察主动脉斑块形成和主动脉窦脂质沉积情况,并计算损伤面积百分比;荧光探针测定主动脉中活性氧(ROS)的生成;蛋白免疫印迹法(Western Blot)检测主动脉中Nrf2/ARE通路相关蛋白表达。结果:与对照组相比,模型组小鼠主动脉ROS增加,血清总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)、氧化型低密度脂蛋白(ox-LDL)、MDA、主动脉斑块损伤和主动脉窦脂质损伤面积百分比、Kelch样环氧氯丙烷相关蛋白1(Keap1)的表达均明显升高,血清SOD、GSH-Px活性、主动脉Nrf2、还原型辅酶/醌氧化还原酶(NQO1)、血红素加氧酶1(HO-1)的表达明显降低,差异均有统计学意义(P<0.05);与模型组相比,橙皮素低、高剂量组小鼠ROS降低,血清TC、TG、LDL-C、ox-LDL、MDA水平、主动脉斑块损伤和主动脉窦脂质损伤面积百分比、Keap1均明显下降,HDL-C、SOD、GSH-Px活性、Nrf2、NQO1、HO-1的表达均明显升高,差异均有统计学意义(P<0.05);鸦胆子苦醇可逆转高剂量橙皮素减轻ApoE^(-/-)小鼠AS病变的作用。结论:橙皮素可能通过激活Nrf2/ARE通路,维持内皮细胞中的氧化还原平衡,减轻ApoE^(-/-)小鼠AS病变,具有较好的抗AS作用。

Upregulation of CDGSH iron sulfur domain 2 attenuates cerebral ischemia/reperfusion injury

CDGSH iron sulfur domain 2 can inhibit ferroptosis,which has been associated with cerebral ischemia/reperfusion,in individuals with head and neck cancer.Therefore,CDGSH iron sulfur domain 2 may be implicated in cerebral ischemia/reperfusion injury.To validate this hypothesis in the present study,we established mouse models of occlusion of the middle cerebral artery and HT22 cell models of oxygen-glucose deprivation and reoxygenation to mimic cerebral ischemia/reperfusion injury in vivo and in vitro,respectively.We found remarkably decreased CDGSH iron sulfur domain 2 expression in the mouse brain tissue and HT22 cells.When we used adeno-associated virus and plasmid to up-regulate CDGSH iron sulfur domain 2 expression in the brain tissue and HT22 cell models separately,mouse neurological dysfunction was greatly improved;the cerebral infarct volume was reduced;the survival rate of HT22 cells was increased;HT22 cell injury was alleviated;the expression of ferroptosis-related glutathione peroxidase 4,cystine-glutamate antiporter,and glutathione was increased;the levels of malondialdehyde,iron ions,and the expression of transferrin receptor 1 were decreased;and the expression of nuclear-factor E2-related factor 2/heme oxygenase 1 was increased.Inhibition of CDGSH iron sulfur domain 2 upregulation via the nuclear-factor E2-related factor 2 inhibitor ML385 in oxygen-glucose deprived and reoxygenated HT22 cells blocked the neuroprotective effects of CDGSH iron sulfur domain 2 up-regulation and the activation of the nuclear-factor E2-related factor 2/heme oxygenase 1 pathway.Our data indicate that the up-regulation of CDGSH iron sulfur domain 2 can attenuate cerebral ischemia/reperfusion injury,thus providing theoretical support from the perspectives of cytology and experimental zoology for the use of this protein as a therapeutic target in patients with cerebral ischemia/reperfusion injury.

Mangiferin Promotes Bregs Level,Activates Nrf2 Antioxidant Signaling,and Inhibits Proinflammatory Cytokine Expression in Murine Splenic Mononuclear Cells In Vitro

Recent studies indicated that regulatory B cells(Bregs)and nuclear factor erythroid 2-related factor 2(Nrf2)antioxidant signaling pathway play important roles in the pathogenesis of chronic graft-versus-host disease(cGVHD).Mangiferin(MA),a polyphenol compound,has been reported to activate Nrf2/antioxidant-responsive element(ARE)signaling pathway.This study was aimed to investigate the effects of MA on Bregs and Nrf2 antioxidant signaling in murine splenic mononuclear cells(MNCs)in vitro.Our results revealed that MA could increase the Bregs level in murine splenic MNCs.Moreover,MA up-regulated the expression of Bregs-associated immunosuppressive factor interleukin-10(IL-10)by activating the Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)and extracellular signal-regulated kinase(ERK)signaling in murine splenic MNCs.Meanwhile,MA inhibited the proinflammatory cytokines IL-2 and interferon-y(INF-y)at both mRNA and protein levels.MA also enhanced the transcription and protein expression of Nrf2 and NADPH quinine oxidoreductase 1(NQOl),whereas decreased that of Kelch-like ECH-associated protein 1(Keapl)in murine splenic MNCs.Moreover,MA promoted the proliferation and inhibited the apoptosis of murine splenic MNCs.These results suggested that MA exerts immunosuppressive effects by upregulating the Bregs level,activating the Nrf2 antioxidant pathway,and inhibiting the expression of pro-immunoinflammatory factors.MA,as a natural immunomodulatory and anti-inflammatory agent,may have a potential role in the prophylaxis and treatment of cGVHD.

姜黄素诱导急性高脂血症大鼠动脉核因子E2相关因子2表达

目的观察姜黄素对急性高脂血症大鼠血脂、血管内皮功能及氧化应激状态的影响,探讨其抗氧化作用与核因子E2相关因子2(Nrf2)表达水平的关系。方法将雄性SD大鼠随机分为5组,即正常对照组、高脂组、姜黄素低剂量组[125 mg/(kg·d)]、姜黄素高剂量组[250 mg/(kg·d)]、阿托伐他汀组[(2.1 mg/(kg·d)]。正常对照组、高脂组用给药溶质玉米油预处理,其他组用相应药物预处理。预处理10天后采用腹腔注射蛋黄乳液的方法建立急性高脂血症大鼠模型,腹腔注射24 h后测定血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDLC)、氧化型低密度脂蛋白(ox-LDL)、一氧化氮(NO)、超氧化物歧化酶(SOD)活力,同时留取主动脉组织测定丙二醛(MDA)含量及行病理学检查。结果与正常对照组比较,高脂组TC、TG、LDLC、ox-LDL、MDA和Nrf2的表达升高,SOD活力、NO含量降低。与高脂组比较,高、低剂量姜黄素组及阿托伐他汀组TC、TG、ox-LDL、MDA降低,Nrf2、SOD活力、NO含量增加。高剂量姜黄素组上述作用优于低剂量姜黄素组。结论姜黄素通过降低血脂及诱导Nrf2的表达,提高主动脉的抗氧化能力,发挥内皮保护作用。

Nrf-2 expression in ulcerative colitis lesions and its correlation with antioxidant enzyme levels and tissue injury

Objective:To study the Nrf-2 expression in ulcerative colitis lesions and its correlation with antioxidant enzyme levels and tissue injury.Methods: Patients who were diagnosed with ulcerative colitis and colon polyp by colonoscopy and pathology biopsy in the Yan'an People's Hospital between May 2013 and April 2016 were selected and enrolled in UC group and control group respectively. Lesion tissue was collected to determine the mRNA expression of Nrf-2, antioxidant enzymes, intestinal mucosa function molecules and intestinal mucosa apoptosis molecules as well as the levels of antioxidant enzymes.Results: Nrf-2, SOD, GSH-Px, CAT, Fas, FasL, NF-kB, TNF-α and Bak mRNA expression in lesions of UC group were significantly higher than those of control group while SOD, GSH-Px and CAT levels as well as cingulin, claudin-2, galectin-1, galectin-3 and galectin-9 mRNA expression were significantly lower than those of control group;Nrf-2 mRNA expression in lesion of UC group was positively correlated with SOD, GSH-Px, CAT, Fas, FasL, NF-kB, TNF-α and Bak mRNA expression, and negatively correlated with SOD, GSH-Px and CAT levels as well as cingulin, claudin-2, galectin-1, galectin-3 and galectin-9 mRNA expression.Conclusions:Compensatory high Nrf-2 expression in ulcerative colitis is closely related to oxidative stress and intestinal mucosa tissue injury.

Oxidative stress in retinal pigment epithelium degeneration:from pathogenesis to therapeutic targets in dry age-related macular degeneration

Age-related macular degeneration is a primary cause of blindness in the older adult population. Past decades of research in the pathophysiology of the disease have resulted in breakthroughs in the form of anti-vascular endothelial growth factor therapies against neovascular age-related macular degeneration;however, effective treatment is not yet available for geographical atrophy in dry agerelated macular degeneration or for preventing the progression from early or mid to the late stage of age-related macular degeneration. Both clinical and experimental investigations involving human agerelated macular degeneration retinas and animal models point towards the atrophic alterations in retinal pigment epithelium as a key feature in age-related macular degeneration progression. Retinal pigment epithelium cells are primarily responsible for cellular-structural maintenance and nutrition supply to keep photoreceptors healthy and functional. The retinal pigment epithelium constantly endures a highly oxidative environment that is balanced with a cascade of antioxidant enzyme systems regulated by nuclear factor erythroid-2-related factor 2 as a main redox sensing transcription factor. Aging and accumulated oxidative stress triggers retinal pigment epithelium dysfunction and eventually death. Exposure to both environmental and genetic factors aggravates oxidative stress damage in aging retinal pigment epithelium and accelerates retinal pigment epithelium degeneration in age-related macular degeneration pathophysiology. The present review summarizes the role of oxidative stress in retinal pigment epithelium degeneration, with potential impacts from both genetic and environmental factors in age-related macular degeneration development and progression. Potential strategies to counter retinal pigment epithelium damage and protect the retinal pigment epithelium through enhancing its antioxidant capacity are also discussed, focusing on existing antioxidant nutritional supplementation, and exploring nuclear factor erythroid-2-related factor 2 and its regulators including REV-ERBα as therapeutic targets to protect against age-related macular degeneration development and progression.

IcarisideⅡ alleviates oxygen-glucose deprivation and reoxygenation-induced PC12 celloxidative injury by activating Nrf2 / SIRT3signaling pathway

OBJECTIVE To investigate icariside(ICS)Ⅱ protects against PC12 cel damage induced by oxygen-glucose deprivation and reoxygenation and explore its mechanism.METHODS The oxidative stress injury model was induced by oxygen-glucose deprivation/reoxygenation(OGD/R) 2 h/24 h in PC12 cells.N-acetyl-lcysteine(NAC),a classical anti-oxidant,was used as positive control.Pharmacodynamic experimental study groups as follows:control,control+ICS Ⅱ50 μmol·L^(-1),OGD/R,OGD/R+ICSⅡ 12.5 μmol·L^(-1),OGD/R + ICS Ⅱ 25 μmol·L^(-1),OGD/R + ICS Ⅱ50 μmol·L^(-1),and OGD/R+NAC 100 μmol·L^(-1) groups.Cell viability and lactate dehydrogenase(LDH) leakage rate were measured by MTT assay and LDH ELISA kit,respectively.Moreover,reactive oxygen species(ROS) ELISA kit was used for detection of intracellular ROS generation,Mito-SOX fluorescence staining was used for detecting production of ROS in mitochondria and mitochondrial membrane potential(MMP)was detected by rhodamine 123 dye.In addition,PC12 cells apoptosis was detected by one-step TUNEL assay.Furthermore,the expressions of nuclear factor erythroid 2-related factors(Nrf2),Keap1,HO^(-1),NQO^(-1),silent information regulator 3(SIRT3),IDH2,Bax,Bcl-2 and caspase 3 were detected by Western blotting analysis.RESULTS The results of MTT and LDH assay showed that OGD/R reduced the cell viability and improved LDH release compared with the control or ICSⅡ 50 μmol·L^(-1) alone(P<0.01).Meanwhile,OGD/R not only increased intracellular and mitochondrial ROS generation,but also elevated the fluorescence intensity of TUNEL staining,at the same time,the MMP was declined when challenged by OGD/R.Furthermore,the Western blotting results showed that OGD/R induced the increase in the expression of cytoplasm-Nrf2,Keap1,Bax and cleaved-caspase 3 level,while the decrease in the expression of nucleus-Nrf2,HO^(-1),NQO^(-1),SIRT3,IDH2 and Bcl-2(P<0.05).However,ICS Ⅱ significantly increased the viability of PC12 cells and reduced LDH leakage(P<0.01).Notably,ICS Ⅱ also suppressed ROS generation both in the intracellular and mitochondria,as well as restored MMP.It was also worthy to note that ICS Ⅱ decreased the expressions of cytoplasmNrf2,Keap1,Bax and the level of cleaved-caspase3,whereas,it increased the expressions of nucleus-Nrf2,HO^(-1),NQO^(-1),SIRT3,IDH2 and Bcl-2(P<0.05).CONCLUSION ICSⅡ reduced OGD/Rinduced oxidative damage in PC12 cells under the laboratory conditions,and its underlying mechanism may be related to the regulation of Nrf2/SIRT3 signaling pathway.