Nuclear Factor Erythroid 2-related Factor 2/antioxidant Response Element Research Articles

Beta-Hydroxybutyrate Mitigates Sensorimotor and Cognitive Impairments in a Photothrombosis-Induced Ischemic Stroke in Mice

The consequences of stroke include cognitive deficits and sensorimotor disturbances, which are largely related to mitochondrial impairments in the brain. In this work, we have shown that the mimetic of the ketogenic diet beta-hydroxybutyrate (βHB) can improve neurological brain function in stroke. At 3 weeks after photothrombotic stroke, mice receiving βHB with drinking water before and after surgery recovered faster in terms of sensorimotor functions assessed by the string test and static rods and cognitive functions assessed by the Morris water maze. At the same time, the βHB-treated mice had lower expression of some markers of astrocyte activation and inflammation (Gfap, Il-1b, Tnf). We hypothesize that long-term administration of βHB promotes the activation of the nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) pathway, which leads to increased expression of antioxidant genes targeting mitochondria and genes involved in signaling pathways necessary for the maintenance of synaptic plasticity. βHB partially maintained mitochondrial DNA (mtDNA) integrity during the first days after photothrombosis. However, in the following three weeks, the number of mtDNA damages increased in all experimental groups, which coincided with a decrease in Ogg1 expression, which plays an important role in mtDNA repair. Thus, we can assume that βHB is not only an important metabolite that provides additional energy to brain tissue during recovery from stroke under conditions of mitochondrial damage but also an important signaling molecule that supports neuronal plasticity and reduces neuroinflammation.

Orientin Modulates Nrf2-ARE, PI3K/Akt, JNK-ERK1/2, and TLR4/NF-kB Pathways to Produce Neuroprotective Benefits in Parkinson's Disease.

Parkinson's disease (PD) is characterized by oxidative stress and neuroinflammation as key pathological features. Emerging evidence suggests that nuclear factor erythroid 2 related factor 2-antioxidant response element (Nrf2-ARE), phosphatidylinositol 3‑kinase-protein kinase B (PI3K-Akt), c-Jun N-terminal kinase-extracellular signal-regulated kinase 1/2 (JNK-ERK1/2), and toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-kB) pathways play pivotal roles in PD pathogenesis. Orientin, a phenolic phytoconstituent, has demonstrated modulatory potential on these pathways in various experimental conditions other than PD. In this study, we aimed to evaluate the neuroprotective effects of Orientin against rotenone-induced neurodegeneration in SH-SY5Y cell lines and the Swiss albino mice model of PD. Orientin was administered at doses 10 and 20µM in cell lines and 10 and 20mg/kg in mice, and its effects on rotenone-induced neurodegeneration were investigated. Oxidative stress markers including mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as inflammatory markers including interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were measured. The expression levels of genes related to Nrf2-ARE (Nrf2), PI3K/Akt (Akt), JNK-ERK1/2 (TNF-α), and TLR4/NF-kB (TNF-α) pathways were measured to understand the modulatory effect of Orientin on these pathways. Additionally, behavioral studies assessing locomotor activity, muscle coordination, and muscle rigidity were conducted with mice. Our results indicate that Orientin dose-dependently attenuated rotenone-induced changes in oxidative stress markers, inflammatory markers, gene expression levels, and behavioral parameters. Therefore, our study concludes that Orientin exhibits significant neuroprotective benefits against rotenone-induced PD by modulating Nrf2-ARE, PI3K-Akt, JNK-ERK1/2, and TLR4/NF-kB pathways.

Transcutaneous Electrical Acupoint Stimulation Improves Postoperative Sleep Quality in Patients Undergoing Laparoscopic Gastrointestinal Tumor Surgery: A Prospective, Randomized Controlled Trial.

This study was conducted to observe the effect of transcutaneous electrical acupoint stimulation (TEAS) on the postoperative sleep quality of patients undergoing gastrointestinal tumor surgery and to verify the possible mechanism. Eighty-three patients were allocated to the TEAS or Sham group. Patients in the TEAS group received TEAS treatment (disperse-dense waves; frequency, 2/100Hz) on bilateral Shenmen (HT7), Neiguan (PC6) and Zusanli (ST36) points for 30min each time, total three times in the perioperative period. In the Sham group, electrodes were placed; however, no current was given. Sleep quality was assessed on the day before surgery (P1) and the first and third days after surgery (D1 and D3) using the Pittsburgh Sleep Quality Index (PSQI) and Athens Insomnia Scale (AIS). Postoperative pain was assessed using visual analog scale (VAS) 72h postoperatively. The incidences of abdominal distension, dizziness, postoperative nausea and vomiting (PONV) and pulmonary complications were recorded. Serum levels of inflammatory cytokines and the expression of key factors of oxidative stress and key molecules of the nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) signal pathway were measured. TEAS ameliorated sleep quality at D1 and D3 (PSQI P < 0.05, AIS P < 0.05) and decreased postoperative pain as demonstrated by lower VAS scores compared to the Sham group (P < 0.05). The incidences of abdominal distension and PONV were also lower in the TEAS group. Markers of oxidative stress were increased (P < 0.05), and the serum concentration of interleukin-6 (IL-6) was significantly lower in the TEAS group. The key mediators of the Nrf2/ARE pathway were enhanced after TEAS. Perioperative TEAS improved postoperative sleep quality, reduced postoperative pain and alleviated postoperative adverse effects in patients undergoing laparoscopic gastrointestinal tumor surgery resection. This may be associated with activating Nrf2/ARE signal pathway and decreasing its inflammatory actions. Chinese Clinical Trial Registry ( http://www.chictr.org.cn/index.aspx ), ChiCTR2100054971.

Mechanism of gypenoside XVII against cerebral ischemia/reperfusion injury based on nuclear factor erythroid 2-related factor 2/antioxidant responsive element signaling pathway

To explore the mechanism of gypenoside XVII against cerebral ischemia/reperfusion (I/R) through nuclear factor erythroid 2-related factor 2/antioxidant responsive element (Nrf2/ARE) signaling pathway. Forty SPF Sprague Dawley (SD) rats were randomly divided into sham operated group, I/R model group, 25, 50 and 100 mg/kg gypenoside XVII groups (n = 8). Gypenoside XVII groups were administered 25, 50 or 100 mg/kg (0.01 mL/g) gypenoside XVII by intragastric administration for 14 days; the other two groups received the same dose of saline. Rat cerebral I/R model was established by modified line bolt method; rats in the sham operated group underwent the same procedure without producing substantial embolization. After 24 hours of reperfusion, the neurological deficit scores of the rats in each group were assessed. Rat abdominal aortic whole blood was collected and the serum reactive oxygen species (ROS), heme oxygenase-1 (HO-1), γ-glutamylcysteine synthase (γ-GCS), superoxide dismutase (SOD), quinone NADH oxidoreductase 1 (NQO1), and malondialdehyde (MDA) were detected. Then whole brain tissue was harvested and penumbra tissue was isolated from cerebral cortex, the general condition of rat brain tissue and the volume of cerebral infarction were evaluated, the histopathological changes in the brain were observed under light microscopy, the mRNA expressions of Nrf2 and Keap1 were measured by real-time fluorescent quantitative polymerase chain reaction (RT-qPCR), the protein expressions of Nrf2 and Keap1 were determined by Western blotting. After 24 hours of reperfusion, compared with the sham operated group, the score of neurological deficit and infarct volume were significantly increased, the NQO1, SOD and γ-GCS levels in serum were significantly decreased, MDA, HO-1 and ROS levels in serum were significantly increased, the Nrf2 and Keap1 mRNA and protein expressions in the ischemic penumbra were significantly increased in rats from I/R model group. Compared with the I/R model group, the neurological deficit scores (1.50±0.53, 1.37±0.52 vs. 2.75±0.46) and brain infarct volume [(19.8±5.1)%, (21.4±6.4)% vs. (42.3±5.8)%] were significantly reduced, serum NQO1, SOD, HO-1 and γ-GCS were significantly increased [NQO1 (ng/L): 186.05±10.38, 220.75±16.22 vs. 131.36±5.95, SOD (kU/L): 63.23±5.30, 72.70±8.62 vs. 36.75±6.55, HO-1 (ng/L): 60.57±7.93, 60.35±4.72 vs. 42.72±4.95, γ-GCS (kU/L): 8.81±0.53, 8.72±0.69 vs. 6.80±0.56], serum MDA and ROS levels were significantly reduced [MDA (μmol/L): 5.94±0.66, 5.61±0.53 vs. 10.88±1.34, ROS (kU/L): 69.11±4.23, 67.12±4.52 vs. 104.43±7.54], the mRNA and protein expressions of Nrf2 and Keap1 in the ischemic penumbra were significantly increased in rats from 50 mg/kg and 100 mg/kg gypenoside XVII groups [Nrf2 mRNA (2-ΔΔCt): 1.90±0.13, 2.13±0.18 vs. 1.48±0.11, Keap1 mRNA (2-ΔΔCt): 1.78±0.11, 1.85±0.10 vs. 1.43±0.10, Nrf2/β-actin: 0.73±0.04, 0.79±0.03 vs. 0.60±0.03, Keap1/β-actin: 0.71±0.01, 0.76±0.03 vs. 0.61±0.01], all the comparative differences were statistically significant (all P < 0.01); 25 mg/kg gypenoside XVII had no significant effect. Gypenoside XVII (50 mg/kg and 100 mg/kg) may play a role in anti-cerebral I/R injury by regulating NQO1, SOD, HO-1, γ-GCS, ROS and MDA through Nrf2/ARE signaling pathway.

Quercetin and resveratrol inhibit ferroptosis independently of Nrf2-ARE activation in mouse hippocampal HT22cells.

Oxidative stress is the central pathomechanism in multiple cell death pathways, including ferroptosis, a form of iron-dependent programmed cell death. Various phytochemicals, which include the inducers of the nuclear factor erythroid-2-related factor 2-antioxidant response element (Nrf2-ARE) transcription pathway, prevent ferroptosis. We recently reported that several compounds, such as the potent Nrf2-ARE inducer curcumin, protect mouse hippocampus-derived HT22cells against ferroptosis independently of Nrf2-ARE activity. The present study characterized the anti-ferroptotic mechanisms of two additional Nrf2-ARE inducers, quercetin and resveratrol. Both compounds prevented erastin- and RSL3-induced ferroptosis of wild-type HT22cells, and also blocked the exacerbated erastin- and RSL3-induced ferroptosis of Nrf2-knockdown HT22cells. In both HT22cells, quercetin and resveratrol blocked erastin- and RSL3-induced elevation in reactive oxygen species. These results suggest that the Nrf2-ARE pathway does protect against ferroptosis, but quercetin and resveratrol act by reducing oxidative stress independently of Nrf2-ARE induction. Quercetin and resveratrol also reduced Fe2+ concentrations in HT22cells and in cell-free reactions. Thus, quercetin and resveratrol likely protect against erastin- and RSL3-induced ferroptosis by inhibiting the iron-catalyzed generation of hydroxyl radicals. Unlike quercetin, resveratrol cannot form a chelate structure with Fe2+ but the density functional theory computation demonstrates that resveratrol can form stable monodentate complexes with the alkene moiety and the electron-rich A ring.

Regulation of myocardial ischemia reperfusion injury signal pathway by flavonoid monomer

Acute myocardial infarction seriously endangers the health of people due to its high morbidity and high mortality. Reperfusion strategy is the preferred treatment strategy for acute myocardial infarction. However, reperfusion may lead to additional heart damage, namely myocardial ischemia reperfusion injury(MIRI). Therefore, how to reduce myocardial ischemia reperfusion injury has become one of the urgent problems to be solved in cardiovascular disease. Traditional Chinese medicine(TCM) has the multi-component, multi-channel, and multi-target advantages in the treatment of MIRI, which offers new ideas in this aspect. TCM containing flavonoids has a variety of biological activities and plays a significant role in the treatment of MIRI, which has great research and development application value. TCM containing flavonoids can regulate multiple signaling pathways of MIRI, such as phosphatidylinositol 3 kinase/kinase B(PI3K/Akt) signaling pathway, Janus kinase/signal transducer and activator of transcriptions(JAK/STAT) signaling pathway, adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK) signaling pathway, mitogen-activated protein kinase(MAPK) signaling pathway, nuclear factor-erythroid 2-related factor 2/antioxidant response element(Nrf2/ARE) signaling pathway, nuclear factor kappa-B(NF-κB) signaling pathway, silent information regulator 1(Sirt1) signaling pathway, and Notch signaling pathway. It reduces MIRI by inhibiting calcium overload, improving energy metabolism, regulating autophagy, and inhibiting ferroptosis and apoptosis. Therefore, a review has been made based on the regulation of relative signaling pathways against MIRI by TCM containing flavonoids, thus providing theoretical support and potential therapeutic strategies for TCM to alleviate MIRI.

Neuroprotective effects of mild hypothermia against traumatic brain injury by the involvement of the Nrf2/ARE pathway.

BackgroundTraumatic brain injury (TBI) is the leading cause of death and disability worldwide. Mild hypothermia (32–35°C) has been found to show neuroprotective effects against TBI. However, the specific mechanism is still elusive. In the current study, we explored the relationship between oxidative damage after TBI and treatment with mild hypothermia as well as the underlying molecular mechanisms.MethodsWe used the closed cortex injury model to perform the brain injury and a temperature monitoring and control system to regulate the body temperature of mice after injury. Adult male C57BL/6 mice were adopted in this study and divided into four experimental groups. Tissue samples were harvested 24 h after injury.ResultsFirst, our results showed that treatment with mild hypothermia significantly improved neurobehavioral dysfunction and alleviated brain edema after TBI. Moreover, treatment with mild hypothermia enhanced the activity of the antioxidant enzymes superoxide dismutase and glutathione peroxidase and reduced the accumulation of lipid peroxidation malondialdehyde. Importantly, the expression and activation of the nuclear factor erythroid 2‐related factor 2‐antioxidant response element (Nrf2‐ARE) pathway were upregulated by mild hypothermia after TBI. Finally, treatment with hypothermia significantly decreased the cell apoptosis induced by TBI.ConclusionOur results showed that the protective effects of mild hypothermia after TBI may be achieved by the upregulation of the Nrf2‐ARE pathway and revealed Nrf2 as a potentially important target to improve the prognosis of TBI.

Promising effects of gingerol against toxins: A review article.

Ginger is a medicinal and valuable culinary plant. Gingerols, as an active constituent in the fresh ginger rhizomes of Zingiber officinale, exhibit several promising pharmacological properties. This comprehensive literature review was performed to assess gingerol's protective and therapeutic efficacy against the various chemical, natural, and radiational stimuli. Another objective of this study was to investigate the mechanism of anti-inflammatory, antioxidant, and antiapoptotic properties of gingerol. It should be noted that the data were gathered from in vivo and in vitro experimental studies. Gingerols can exert their protective activity through different mechanisms and cell signaling pathways. For example, these are mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-kB), Wnt/β-catenin, nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE), transforming growth factor beta1/Smad3 (TGF-β1/Smad3), and extracellular signal-related kinase/cAMP-response element-binding protein (ERK/CREB). We hope that more researchers can benefit from this review to conduct preclinical and clinical studies, treat cancer, inflammation, and attenuate the side effects of drugs and industrial pollutants.

Food-Derived Pharmacological Modulators of the Nrf2/ARE Pathway: Their Role in the Treatment of Diseases.

Oxidative stress, which refers to unbalanced accumulation of reactive oxygen species (ROS) levels in cells, has been linked to acute and chronic diseases. Nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) pathway plays a vital role in regulating cytoprotective genes and enzymes in response to oxidative stress. Therefore, pharmacological regulation of Nrf2/ARE pathway is an effective method to treat several diseases that are mainly characterized by oxidative stress and inflammation. Natural products that counteract oxidative stress by modulating Nrf2 have contributed significantly to disease treatment. In this review, we focus on bioactive compounds derived from food that are Nrf2/ARE pathway regulators and describe the molecular mechanisms for regulating Nrf2 to exert favorable effects in experimental models of diseases.

Saponins from Panax japonicus ameliorate age-related renal fibrosis by inhibition of inflammation mediated by NF-κB and TGF-β1/Smad signaling and suppression of oxidative stress via activation of Nrf2-ARE signaling

BackgroundThe decreased renal function is known to be associated with biological aging, of which the main pathological features are chronic inflammation and renal interstitial fibrosis. In previous studies, we reported that total saponins from Panax japonicus (SPJs) can availably protect acute myocardial ischemia. We proposed that SPJs might have similar protective effects for aging-associated renal interstitial fibrosis. Thus, in the present study, we evaluated the overall effect of SPJs on renal fibrosis. MethodsSprague-Dawley (SD) aging rats were given SPJs by gavage beginning from 18 months old, at 10 mg/kg/d and 60 mg/kg/d, up to 24 months old. After the experiment, changes in morphology, function and fibrosis of their kidneys were detected. The levels of serum uric acid (UA), β2-microglobulin (β2-MG) and cystatin C (Cys C) were assayed with ELISA kits. The levels of extracellular matrix (ECM), matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), inflammatory factors and changes of oxidative stress parameters were examined. ResultsAfter SPJs treatment, SD rats showed significantly histopathological changes in kidneys accompanied by decreased renal fibrosis and increased renal function; As compared with those in 3-month group, the levels of serum UA, Cys C and β2-MG in 24-month group were significantly increased (p < 0.05). Compared with those in the 24-month group, the levels of serum UA, Cys C and β2-MG in the SPJ-H group were significantly decreased. While ECM was reduced and the levels of MMP-2 and MMP-9 were increased, the levels of TIMP-1, TIMP-2 and transforming growth factor-β1 (TGF-β1)/Smad signaling were decreased; the expression level of phosphorylated nuclear factor kappa-B (NF-κB) was down-regulated with reduced inflammatory factors; meanwhile, the expression of nuclear factor erythroid 2-related factor 2-antioxidant response element (Nrf2-ARE) signaling was aggrandized. ConclusionThese results suggest that SPJs treatment can improve age-associated renal fibrosis by inhibiting TGF-β1/Smad, NFκB signaling pathways and activating Nrf2-ARE signaling pathways and that SPJs can be a potentially valuable anti-renal fibrosis drug.

Troxerutin attenuates cognitive decline in the hippocampus of male diabetic rats by inhibiting NADPH oxidase and activating the Nrf2/ARE signaling pathway.

Diabetes‑associated cognitive decline is a recently identified a potential complication of diabetes. The present study was designed to examine the effects of troxerutin, a potent antioxidant, on cognitive function in rats with streptozotocin‑induced diabetes and to further explore the potential underlying mechanisms. Cognitive functions were investigated by the Morris water maze test. The malondialdehyde (MDA) level and superoxide dismutase (SOD) activity in the hippocampus were assessed as the parameters of oxidative stress. Subunits of the NADPH oxidase (NOX) expression and nuclear factor erythroid 2‑related factor 2/antioxidant responsive element (Nrf2/ARE) signaling pathway were detected to explore the potential underlying mechanisms. The water maze test revealed that troxerutin significantly improved cognitive impairment in diabetic rats. Troxerutin treatment attenuated oxidative stress in the hippocampus of diabetic rats, as evidenced by the decreased MDA level and the increased SOD activity. Moreover, troxerutin activated the Nrf2/ARE signaling pathway via Nrf2 nuclear translocation in the cells in the hippocampus of diabetic rats. Troxerutin elevated the expression levels of the antioxidant enzymes, heme oxygenase‑1 (HO‑1) and NAD(P)H:quinone oxidoreductase (NQO1), and decreased the expression levels of the NOX subunits, gp91phox, p47phox and p22phox. On the whole, these findings demonstrate that troxerutin exerts neuroprotective effects against diabetes‑associated cognitive decline by suppressing oxidative stress in the hippocampus of rats with streptozotocin‑induced diabetes. Troxerutin may thus prove to be a potential therapeutic medicine for the treatment of diabetes‑associated cognitive decline.

Effect of Prooxidative Natural Products: Comparison of the OSI1 (YKL071w) Promoter Luciferase Construct from Yeast with an Nrf2/Keap Reporter System

The oxidative stress response (OSR) in yeast is under the control of oxidation-sensitive cysteines in the Yap1p transcription factor, and fusion of the Yap1p-dependent OS-induced promoter of the YKL071w gene (OSI1) to a luciferase coding sequence makes a sensitive reporter for OS induced by electrophiles. In mammalian cells, the OSR induced by electrophiles is coordinated in a mechanistically similar way via oxidation-sensitive cysteines in the kelch-like ECH-associated protein 1 (Keap1)– nuclear factor erythroid 2-related factor 2 / antioxidant response element ( Nrf2/ARE) system. Many electrophilic oxidants have already been independently shown to trigger both the Yap1 and Keap1 systems. Here, we investigated the responses of Yap1 and Keap1 reporters to sulforaphane (SFN), allyl isothiocyanate (AITC), phenylethyl isothiocyanate (PEITC), previously known to stimulate Keap1–Nrf2/ARE but not known to activate Yap1, and as a positive control, allicin, previously reported to stimulate both Yap1 and Nrf2. We have compared the reciprocal responsiveness of the respective reporter systems and show that the yeast reporter system can have predictive value for electrophiles that stimulate the mammalian Keap1–Nrf2/ARE system.

Dimethyl Fumarate Alleviates Dextran Sulfate Sodium-Induced Colitis, through the Activation of Nrf2-Mediated Antioxidant and Anti-inflammatory Pathways.

Oxidative stress and chronic inflammation play critical roles in the pathogenesis of ulcerative colitis (UC) and inflammatory bowel diseases (IBD). A previous study has demonstrated that dimethyl fumarate (DMF) protects mice from dextran sulfate sodium (DSS)-induced colitis via its potential antioxidant capacity, and by inhibiting the activation of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome. This study aims to clarify the nuclear factor erythroid 2-related factor 2/antioxidant responsive element (Nrf2/ARE) pathway pharmacological activation and anti-inflammatory effect by DMF, through focusing on other crucial antioxidant enzymes and inflammatory mediator, including glutamate-cysteine ligase catalytic subunit (GCLC), glutathione peroxidase (GPX) and cyclooxygenase-2 (COX-2), in a DSS-induced colitis mouse model. The oral administration of DMF attenuated the shortening of colons and alleviated colonic inflammation. Furthermore, the expression of key antioxidant enzymes, including GCLC and GPX, in the colonic tissue were significantly increased by DMF administration. In addition, protein expression of the inflammatory mediator, COX-2, was reduced by DMF administration. Our results suggest that DMF alleviates DSS-induced colonic inflammatory damage, likely via up-regulating GCLC and GPX and down-regulating COX-2 protein expression in colonic tissue.

Non-Phosphorylatable PEA-15 Sensitises SKOV-3 Ovarian Cancer Cells to Cisplatin.

The efficacy of cisplatin-based chemotherapy in ovarian cancer is often limited by the development of drug resistance. In most ovarian cancer cells, cisplatin activates extracellular signal-regulated kinase1/2 (ERK1/2) signalling. Phosphoprotein enriched in astrocytes (PEA-15) is a ubiquitously expressed protein, capable of sequestering ERK1/2 in the cytoplasm and inhibiting cell proliferation. This and other functions of PEA-15 are regulated by its phosphorylation status. In this study, the relevance of PEA-15 phosphorylation state for cisplatin sensitivity of ovarian carcinoma cells was examined. The results of MTT-assays indicated that overexpression of PEA-15AA (a non-phosphorylatable variant) sensitised SKOV-3 cells to cisplatin. Phosphomimetic PEA-15DD did not affect cell sensitivity to the drug. While PEA-15DD facilitates nuclear translocation of activated ERK1/2, PEA-15AA acts to sequester the kinase in the cytoplasm as shown by Western blot. Microarray data indicated deregulation of thirteen genes in PEA-15AA-transfected cells compared to non-transfected or PEA-15DD-transfected variants. Data derived from The Cancer Genome Atlas (TCGA) showed that the expression of seven of these genes including EGR1 (early growth response protein 1) and FLNA (filamin A) significantly correlated with the therapy outcome in cisplatin-treated cancer patients. Further analysis indicated the relevance of nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) signalling for the favourable effect of PEA-15AA on cisplatin sensitivity. The results warrant further evaluation of the PEA-15 phosphorylation status as a potential candidate biomarker of response to cisplatin-based chemotherapy.

Testosterone propionate activated the Nrf2-ARE pathway in ageing rats and ameliorated the age-related changes in liver

The present study aimed to evaluate the protective efficacy of testosterone propionate (TP) on age-related liver changes via activation of the nuclear factor erythroid 2-related factor 2-antioxidant response element (Nrf2-ARE) pathway in aged rats. Aged rats received subcutaneous injections of TP (2 mg/kg/d, 84 days). Oxidative stress parameters and the expression levels of signal transducer and activator of transcription 5b (STAT5b), Kelch-like ECH associating protein-1 (Keap1), Nrf2, haem oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase-1 (NQO1) in liver tissues were examined to check whether the Nrf2-ARE pathway was involved in the age-related changes in liver. Our results showed that TP supplementation alleviated liver morphology, liver function and liver fibrosis; improved oxidative stress parameters; and increased the expression of STAT5b, Nrf2, HO-1 and NQO-1 and decreased the expression of Keap1 in the liver tissues of aged rats. These results suggested that TP increased the expression of STAT5b, and then activated the Nrf2-ARE pathway and promoted antioxidant mechanisms in aged rats. These findings may provide new therapeutic uses for TP in patients with age-related liver changes.

The Effects of Dimethyl Fumarate on Atherosclerosis in the Apolipoprotein E-Deficient Mouse Model with Streptozotocin-Induced Hyperglycemia Mediated By the Nuclear Factor Erythroid 2-Related Factor 2/Antioxidant Response Element (Nrf2/ARE) Signaling Pathway.

BackgroundThis study aimed to investigate the effects of dimethyl fumarate (DMF) on thoracic aortic atherosclerosis in the apolipoprotein E (apo-E)-deficient mouse model with streptozotocin (STZ)-induced hyperglycemia, and the signaling pathways involved.Material/MethodsEight-week-old ApoE−/− male mice (n=30) were randomly divided into three groups: the Control group (ApoE−/−) (n=10); the diabetic model (STZ) group (n=10); and the DMF-treated (25 mg/kg) diabetic model (DMF+STZ) group (n=10). The area of the thoracic aortic atherosclerosis was determined by histology. Reactive oxygen species (ROS) levels in mouse serum and homogenates of the thoracic aorta were determined by colorimetry. Levels of nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase subunit gp91phox were detected by immunological hybridization, and levels of heme oxygenase-1 (HO-1) were measured by enzyme-linked immunosorbent assay (ELISA).ResultsCompared with the Control group, in the STZ group, the area of aortic atherosclerosis was significantly increased, the levels of serum and aortic ROS, HO-1, nuclear factor-κB (NF-κB), intercellular adhesion molecule 1 (ICAM-1), and gp91phox were increased, and nuclear factor erythroid 2-related factor 2 (Nrf2), endothelial nitric oxide synthase (eNOS), and phosphorylated eNOS (p-eNOS) were significantly reduced. Compared with the STZ group, in the DMF+STZ group, the area of aortic atherosclerosis was significantly reduced, the levels of serum and aortic ROS, HO-1, NF-κB, ICAM-1, and gp91phox were significantly reduced, and Nrf2, eNOS, and p-eNOS were significantly increased.ConclusionsIn the apo-E-deficient mouse model with STZ-induced hyperglycemia, DMF reduced the development of atherosclerosis of the thoracic aorta through the nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) signaling pathway.

Melatonin enhances porcine embryo development via the Nrf2/ARE signaling pathway.

Oxidative stress (OS) is a major problem during in vitro culture of embryos. Numerous studies have shown that melatonin, which is known to have antioxidant properties, prevents the occurrence of OS in embryos. However, the molecular mechanisms by which melatonin prevents OS in embryos are still unclear. The present study suggests a possible involvement of the nuclear factor erythroid 2-related factor 2/antioxidant-responsive element (Nrf2/ARE) signaling pathway, which is one of the prominent signals for OS prevention through Nrf2 activation, connecting melatonin, OS prevention and porcine embryonic development. The aim of this study was to investigate the effects of melatonin (10-7 M) on porcine embryonic development via the Nrf2/ARE signaling pathway; brusatol (50 nM; Nrf2 specific inhibitor) was used to validate the mechanism. Treatment of porcine embryo with melatonin significantly increased formation rates of blastocysts and their total cell numbers and also upregulated the expression of Nrf2/ARE signaling and apoptosis-related genes (MT2, NRF2, UCHL, HO-1, SOD1 and BCL-2). Furthermore, the expression of proteins (NRF2 and MT2) was also upregulated in the melatonin-treated group. Concomitantly, brusatol significantly inhibited these effects, upregulating the expression of KEAP1 and BAX, including the expression level of KEAP1 protein. These results provide evidences that melatonin prevents OS through Nrf2/ARE signaling pathway in porcine in vitro fertilization -derived embryos.

Sulforaphane Protects the Male Reproductive System of Mice from Obesity-Induced Damage: Involvement of Oxidative Stress and Autophagy.

(1) Background: In recent decades, the prevalence of obesity has grown rapidly worldwide, thus causing many diseases, including male hypogonadism. Sulforaphane (SFN), an isothiocyanate compound, has been reported to protect the reproductive system. This research investigated the protective effect of SFN against obesity-induced impairment in the male reproductive system and explored the potential mechanism involved in mice. (2) Methods: One hundred thirty mice were divided into 5 groups (Control, DIO (diet-induced obesity), DIO + SFN 5 mg/kg, DIO + SFN 10 mg/kg, and DIO + SFN 20 mg/kg). The effects of SFN on the male reproductive system were determined based on the sperm count and motility, relative testes and epididymis weights, hormone levels, and pathological analyses. Oxidative stress was determined by measuring malondialdehyde (MDA), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione (GSH), H2O2, catalase (CAT), and glutathione peroxidase (GSH-PX) levels. Protein expression of nuclear factor erythroid-2 related factor 2 (Nrf2), Kelch-like ECH-associated protein-1 (Keap1), Microtubule-associated protein light chain 3 (LC3), Beclin1, and P62 were determined by western blotting. (3) Results: High-fat diet (HFD)-induced obesity significantly decreased relative testes and epididymis weights, sperm count and motility, and testosterone levels but increased leptin and estradiol levels. SFN supplementation ameliorated these effects. Additionally, SFN administration inhibited the obesity-induced MDA accumulation and increased the SOD level. Western blot indicated that SFN had an important role in the downregulation of Keap1. Moreover, SFN treatment attenuated obesity-induced autophagy, as detected by LC3 and Beclin1. (4) Conclusions: SFN ameliorated the reproductive toxicity associated with obesity by inhibiting oxidative stress mediated by the nuclear factor erythroid-2 related factor 2/ antioxidant response element (Nrf2/ARE) signaling pathway and recovery of normal autophagy.

L-Methionine activates Nrf2-ARE pathway to induce endogenous antioxidant activity for depressing ROS-derived oxidative stress in growing rats.

Methionine is an essential sulfur-containing amino acid. To elucidate the influence of l-methionine on activation of the nuclear factor erythroid 2-related factor 2-antioxidant responsive element (Nrf2-ARE) antioxidant pathway to stimulate the endogenous antioxidant activity for depressing reactive oxygen species (ROS)-derived oxidative stress, male Wistar rats were orally administered l-methionine daily for 14 days. With the intake of l-methionine, Nrf2 was activated by l-methionine through depressing Keap1 and Cul3, resulting in upregulation of ARE-driven antioxidant expression (glutamate cysteine ligase catalytic subunit, glutamate cysteine ligase modulatory subunit, glutathione synthase (GS), catalase (CAT), superoxide dismutase (SOD), heme oxygenase 1, NAD(P)H:quinone oxidoreductase 1, glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPx)) with increasing l-methionine availability. Upon activation of Nrf2, glutathione synthesis was increased through upregulated expression of methionine adenosyltransferase, S-adenosylhomocysteine hydrolase, cystathionine β-synthase, cystathionine γ-lyse, glutamate cysteine ligase (GCL) and GS, while hepatic expressions of methionine sulfoxide reductases (MsrA, MsrB2, MsrB3) and hepatic enzyme activities (CAT, SOD, GCL, GR, GST, GPx) were uniformly stimulated with increasing consumption of l-methionine. As a result, hepatic content of ROS and MDA were effectively reduced by l-methionine intake. The present study demonstrates that methionine availability plays a critical role in activation of the Nrf2-ARE pathway to induce an endogenous antioxidant response for depressing ROS-derived oxidative stress, which is primarily attributed to the stimulation of methionine sulfoxide reductase expression and glutathione synthesis. © 2019 Society of Chemical Industry.

Chitosan oligosaccharides prevent doxorubicin-induced oxidative stress and cardiac apoptosis through activating p38 and JNK MAPK mediated Nrf2/ARE pathway

Doxorubicin (DOX) is one of the most effective chemotherapeutic drugs; however, the incidence of cardiotoxicity compromises its therapeutic index. Oxidative stress and apoptosis are believed to be involved in DOX-induced cardiotoxicity. Chitosan oligosaccharides (COS), the enzymatic hydrolysates of chitosan, have been reported to possess diverse biological activities including antioxidant and anti-apoptotic properties. The objective of the present study was to investigate the potential role of COS against DOX-induced cardiotoxicity, and the effects of COS on apoptosis and oxidative stress in rats and H9C2 cells. Furthermore, we also shed light on the involved pathways during the whole process. For this purpose, first, we demonstrated that COS exhibited a significant protective effect on cardiac tissue by not only inducing a decrease in body and heart growth but also ameliorated oxidative damage and ECG alterations in DOX-treated rats. Second, we found that COS reversed the decrease of cell viability induced by DOX, reduced the intracellular reactive oxygen species (ROS), increased the mitochondrial membrane potential (MMP) and Bcl-2/Bax ratio. COS treatment also results in reduced caspase-3 and caspase-9 expressions, and an increase in the phosphorylation of MAPKs (mitogen-activated protein kinases) in DOX-exposed H9C2 cells. Additionally, cellular homeostasis was re-established via stabilization of MAPK mediated nuclear factor erythroid 2-related factor 2/antioxidant-response element (Nrf2/ARE) signaling and transcription of downstream cytoprotective genes. In summary, these findings suggest that COS could be a potential candidate for the prevention and treatment of DOX-induced cardiotoxicity.