scholarly journals STAT6/VDR Axis Mitigates Lung Inflammatory Injury by Promoting Nrf2 Signaling Pathway

2022 ◽  
Vol 2022 ◽  
pp. 1-15
Author(s):  
Youjing Yang ◽  
Qianmin Li ◽  
Shuhui Wei ◽  
Kaimiao Chu ◽  
Lian Xue ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Nuclear Translocation ◽  
Cell Damage ◽  
Airway Epithelial Cells ◽  
Health Concern ◽  
Global Public Health ◽  
Inflammatory Injury ◽  
Genetic Ablation ◽  
Nrf2 Signaling Pathway

Lung inflammatory injury is a global public health concern. It is characterized by infiltration of diverse inflammatory cells and thickening of pulmonary septum along with oxidative stress to airway epithelial cells. STAT6 is a nuclear transcription factor that plays a crucial role in orchestrating the immune response, but its function in tissue inflammatory injury has not been comprehensively studied. Here, we demonstrated that STAT6 activation can protect against particle-induced lung inflammatory injury by resisting oxidative stress. Specifically, genetic ablation of STAT6 was observed to worsen particle-induced lung injury mainly by disrupting the lungs’ antioxidant capacity, as reflected by the downregulation of the Nrf2 signaling pathway, an increase in malondialdehyde levels, and a decrease in glutathione levels. Vitamin D receptor (VDR) has been previously proved to positively regulate Nrf2 signals. In this study, silencing VDR expression in human bronchial epithelial BEAS-2B cells consistently suppressed autophagy-mediated activation of the Nrf2 signaling pathway, thereby aggravating particle-induced cell damage. Mechanically, STAT6 activation promoted the nuclear translocation of VDR, which increased the transcription of autophagy-related genes and induced Nrf2 signals, and silencing VDR abolished these effects. Our research provides important insights into the role of STAT6 in oxidative damage and reveals its potential underlying mechanism. This information not only deepens the appreciation of STAT6 but also opens new avenues for the discovery of therapies for inflammatory respiratory system disorders.

l-carnitine protects human hepatocytes from oxidative stress-induced toxicity through Akt-mediated activation of Nrf2 signaling pathway

2016 ◽  
Vol 94 (5) ◽  
pp. 517-525 ◽  
Author(s):  
Jinlian Li ◽  
Yanli Zhang ◽  
Haiyun Luan ◽  
Xuehong Chen ◽  
Yantao Han ◽  
...  
Keyword(s):  
Protective Effect ◽  
Signaling Pathway ◽  
Nuclear Translocation ◽  
Cell Damage ◽  
Binding Activity ◽  
Akt Pathway ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Akt Inhibitor ◽  
Nrf2 Signaling Pathway

In our previous study, l-carnitine was shown to have cytoprotective effect against hydrogen peroxide (H2O2)-induced injury in human normal HL7702 hepatocytes. The aim of this study was to investigate whether the protective effect of l-carnitine was associated with the nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2) pathway. Our results showed that pretreatment with l-carnitine augmented Nrf2 nuclear translocation, DNA binding activity and heme oxygenase-1 (HO-1) expression in H2O2-treated HL7702 cells, although l-carnitine treatment alone had no effect on them. Analysis using Nrf2 siRNA demonstrated that Nrf2 activation was involved in l-carnitine-induced HO-1 expression. In addition, l-carnitine-mediated protection against H2O2 toxicity was abrogated by Nrf2 siRNA, indicating the important role of Nrf2 in l-carnitine-induced cytoprotection. Further experiments revealed that l-carnitine pretreatment enhanced the phosphorylation of Akt in H2O2-treated cells. Blocking Akt pathway with inhibitor partly abrogated the protective effect of l-carnitine. Moreover, our finding demonstrated that the induction of Nrf2 translocation and HO-1 expression by l-carnitine directly correlated with the Akt pathway because Akt inhibitor showed inhibitory effects on the Nrf2 translocation and HO-1 expression. Altogether, these results demonstrate that l-carnitine protects HL7702 cells against H2O2-induced cell damage through Akt-mediated activation of Nrf2 signaling pathway.

scholarly journals Honokiol Ameliorates Myocardial Ischemia/Reperfusion Injury in Type 1 Diabetic Rats by Reducing Oxidative Stress and Apoptosis through Activating the SIRT1-Nrf2 Signaling Pathway

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Bin Zhang ◽  
Mengen Zhai ◽  
Buying Li ◽  
Zhenhua Liu ◽  
Kaifeng Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Ischemia ◽  
Signaling Pathway ◽  
Nuclear Translocation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen Species Generation ◽  
Nrf2 Signaling Pathway ◽  
Myocardial Ischemia Reperfusion

Reducing oxidative stress is a crucial therapeutic strategy for ameliorating diabetic myocardial ischemia/reperfusion (MI/R) injury. Honokiol (HKL) acts as an effective cardioprotective agent for its strong antioxidative activity. However, its roles and underlying mechanisms against MI/R injury in type 1 diabetes (T1D) remain unknown. Since SIRT1 and Nrf2 are pivotal regulators in diabetes mellitus patients suffering from MI/R injury, we hypothesized that HKL ameliorates diabetic MI/R injury via the SIRT1-Nrf2 signaling pathway. Streptozotocin-induced T1D rats and high-glucose-treated H9c2 cells were exposed to HKL, with or without administration of the SIRT1 inhibitor EX527, SIRT1 siRNA, or Nrf2 siRNA, and then subjected to I/R operation. We found that HKL markedly improved the postischemic cardiac function, decreased the infarct size, reduced the myocardial apoptosis, and diminished the reactive oxygen species generation. Intriguingly, HKL remarkably activated SIRT1 signaling, enhanced Nrf2 nuclear translocation, increased antioxidative signaling, and decreased apoptotic signaling. However, these effects were largely abolished by EX527 or SIRT1 siRNA. Additionally, our cellular experiments showed that Nrf2 siRNA blunted the cytoprotective effects of HKL, without affecting SIRT1 expression and activity. Collectively, these novel findings indicate that HKL abates MI/R injury in T1D by ameliorating myocardial oxidative damage and apoptosis via the SIRT1-Nrf2 signaling pathway.

scholarly journals Alginate Oligosaccharide Ameliorates D-Galactose-Induced Kidney Aging in Mice through Activation of the Nrf2 Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hui Pan ◽  
Wenjing Feng ◽  
Ming Chen ◽  
Hong Luan ◽  
Yi Hu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Aging Process ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Heme Oxygenase 1 ◽  
Quinone Oxidoreductase ◽  
Nrf2 Signaling Pathway ◽  
Wide Range ◽  
Alginate Oligosaccharide

Aging is an independent risk factor for the development of age-related progressive kidney injury. As a part of the aging process, kidney aging has been indicated to be associated with oxidative stress-induced damage. Ameliorating oxidative damage is therefore considered a promising strategy for delaying kidney aging. Alginate oligosaccharide (AOS) has been reported to have a wide range of biological and pharmacological activities. However, no studies have focused on the role of AOS in delaying the kidney aging process. In this study, we aimed to evaluate the potential effects of AOS on kidney aging and its possible mechanisms. Subcutaneous injection of D-galactose (D-gal) (200 mg·kg-1·d-1) in C57BL/6J mice for 8 weeks was used to establish the aging model. AOS (200 mg·kg-1·d-1) was administered via oral gavage for the last four weeks. As a result, AOS inhibited the D-gal-induced upregulation of aging markers and significantly improved the kidney index and kidney function of D-gal-induced mice. In addition, AOS ameliorated the degree of tissue damage and fibrosis in the aging kidney. To further explore the potential mechanisms by which AOS attenuates the kidney aging process, the associated oxidative stress-induced damage was analyzed in depth. The data showed that AOS upregulated the expression of Klotho and decreased malondialdehyde levels by increasing the expression of antioxidant enzymes. Furthermore, our results suggested that AOS activated the nuclear factor erythrogen-2 associated factor 2 (Nrf2) pathway by promoting Nrf2 nuclear translocation in aging mice and upregulated the downstream expression of heme oxygenase-1 (HO-1) and NADPH quinone oxidoreductase 1 (NQO1). In conclusion, the present study demonstrated that AOS is a promising agent for attenuating kidney aging, and the underlying molecular mechanisms are related to the activation of the Nrf2 signaling pathway.

scholarly journals Inhibition of the Keap1/Nrf2 Signaling Pathway Significantly Promotes the Progression of Type 1 Diabetes Mellitus

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Yanmei Lou ◽  
Muyan Kong ◽  
Leyan Li ◽  
Yu Hu ◽  
Wenjun Zhai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Cell Damage ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Min6 Cells ◽  
Nrf2 Signaling Pathway

Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by insulin deficiency due to pancreatic β-cell damage and leads to hyperglycemia. The precise molecular mechanisms of the etiology of T1DM are not completely understood. Oxidative stress and the antioxidant status of pancreatic β-cells play a vital role in the pathogenesis and progression of T1DM. The Keap1/Nrf2 signaling pathway plays a critical role in cellular resistance to oxidative stress. This study is aimed at investigating the role of the Keap1/Nrf2 signaling pathway in the progression of T1DM. An alloxan- (ALX-) stimulated T1DM animal model in wild-type (WT) and Nrf2 knockout (Nrf2-/-) C57BL/6J mice and a mouse pancreatic β-cell line (MIN6) were established. Compared with the tolerant (ALX exposure, nondiabetic) WT mice, the sensitive (ALX exposure, diabetic) WT mice exhibited higher blood glucose levels and lower plasma insulin levels. The Keap1/Nrf2 signaling pathway was significantly inhibited in the sensitive WT mice, which was reflected by overexpression of Keap1 and low expression of Nrf2, accompanied by a marked decrease in the expression of the antioxidative enzymes. Compared with WT mice, the Nrf2-/- mice had an increased incidence of T1DM and exhibited more severe pancreatic β-cell damage. The results of in vitro experiments showed that ALX significantly inhibited the viability and proliferation and promoted the apoptosis of MIN6 cells. ALX also markedly increased intracellular ROS production and caused DNA damage in MIN6 cells. In addition, the Keap1/Nrf2 signaling pathway was significantly inhibited in the damaged MIN6 cells. Moreover, Nrf2 silencing by transfection with Nrf2 siRNA markedly exacerbated ALX-induced MIN6 cell injury. Conclusively, this study demonstrates that inhibition of the Keap1/Nrf2 signaling pathway could significantly promote the incidence of T1DM. This study indicates that activation of Keap1/Nrf2 signaling in pancreatic β-cells may be a useful pharmacological strategy for the clinical prevention and treatment of T1DM.

scholarly journals Novel Oral-edaravone Attenuates Diastolic Dysfunction of Diabetic Cardiomyopathy via Activating the Nrf2 Signaling Pathway

2021 ◽  
Author(s):  
Ling Wang ◽  
Yue-Qin Zeng ◽  
Juan-Hua Gu ◽  
Rui Song ◽  
Peng-Hui Cang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diastolic Dysfunction ◽  
Signaling Pathway ◽  
Diabetic Cardiomyopathy ◽  
Nuclear Translocation ◽  
Therapeutic Potential ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
H9c2 Cells ◽  
Quinone Oxidoreductase ◽  
Nrf2 Signaling Pathway

Abstract Background Diastolic dysfunction is the most common change of diabetic cardiomyopathy (DCM), but there is no effective clinical treatment at present. Oxidative stress plays a crucial role in the pathophysiological process of diabetic diastolic dysfunction including hypertrophy, apoptosis and fibrosis. The novel Oral-edaravone (OED) alleviates oxidative stress by scavenging free radical and may be suitable for the treatment of chronic diseases such as DCM. Methods DCM was induced by high sugar and high fat diet with intraperitoneal injection of streptozotocin (STZ) in rats. OED (3mg/kg/day) was administration for 4 weeks. Cardiac structure and function were measured using transthoracic echocardiography. H9C2 cardiomyocytes with Nrf2 transfection or not were incubated in glucolipotoxicity and treated with OED for 48 hours to further explore the mechanism. Results In type 2 diabetic rats,oral administration of OED for 4 weeks decreased malondialdehyde (MDA) and increased superoxide dismutase (SOD). OED significantly improved E/A ratio and myocardium hypertrophy accompanied by decreased cross-sectional area of cardiomyocytes, proportion of apoptotic cells, collagen volume fractions and depositions of collagen I/III. In H9C2 cells, OED reduced reactive oxygen species (ROS), cell surface area and TUNEL-positive cells induced by glucolipotoxicity. OED remarkably up-regulated the expression of the Nrf2 signaling pathway both in vivo and in vitro, further promoted Nrf2 nuclear translocation and up-regulated nicotinamide adenine dinucleotide phosphate quinone oxidoreductase (NQO1) and heme oxygenase (HO-1). Moreover, Nrf2 gene silencing abolished the protective effect of OED in H9c2 cells. Conclusion Our findings demonstrated that OED treatment has the therapeutic potential to ameliorate diastolic dysfunction of DCM. The effect is mainly achieved by attenuating hyperglycemia and hyperlipidemia-induced cardiomyocytes hypertrophy, apoptosis and fibrosis via activating the Nrf2 signaling pathway.

scholarly journals β-Asarone Ameliorates β-Amyloid–Induced Neurotoxicity in PC12 Cells by Activating P13K/Akt/Nrf2 Signaling Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Miaomiao Meng ◽  
Lijuan Zhang ◽  
Di AI ◽  
Hongyun Wu ◽  
Wei Peng
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Neuronal Damage ◽  
Cell Model ◽  
Cell Damage ◽  
Neuroprotective Effects ◽  
Akt Phosphorylation ◽  
Nrf2 Signaling Pathway ◽  
Amyloid Aβ ◽  
Β Amyloid

Accumulation of β-amyloid (Aβ) causes oxidative stress, which is the major pathological mechanism in Alzheimer’s disease (AD). β-asarone could reduce Aβ-induced oxidative stress and neuronal damage, but the molecular mechanism remains elusive. In this study, we used an Aβ-stimulated PC12 cell model to explore the neuroprotective effects and potential mechanisms of β-asarone. The results showed that β-asarone could improve cell viability and weaken cell damage and apoptosis. β-asarone could also decrease the level of ROS and MDA; increase the level of SOD, CAT, and GSH-PX; and ameliorate the mitochondrial membrane potential. Furthermore, β-asarone could promote the expression of Nrf2 and HO-1 by upregulating the level of PI3K/Akt phosphorylation. In conclusion, β-asarone could exert neuroprotective effects by modulating the P13K/Akt/Nrf2 signaling pathway. β-asarone might be a promising therapy for AD.

scholarly journals Nrf2 Activation Attenuates Acrylamide-Induced Neuropathy in Mice

2021 ◽  
Vol 22 (11) ◽  
pp. 5995
Author(s):  
Chand Basha Davuljigari ◽  
Frederick Adams Ekuban ◽  
Cai Zong ◽  
Alzahraa A. M. Fergany ◽  
Kota Morikawa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Messenger Rna ◽  
Hepatic Necrosis ◽  
Related Factor ◽  
Necrosis Factor Alpha ◽  
Adult Mice ◽  
Nrf2 Signaling Pathway ◽  
Antioxidant Proteins ◽  
Oxide Synthase

Acrylamide is a well characterized neurotoxicant known to cause neuropathy and encephalopathy in humans and experimental animals. To investigate the role of nuclear factor erythroid 2-related factor 2 (Nrf2) in acrylamide-induced neuropathy, male C57Bl/6JJcl adult mice were exposed to acrylamide at 0, 200 or 300 ppm in drinking water and co-administered with subcutaneous injections of sulforaphane, a known activator of the Nrf2 signaling pathway at 0 or 25 mg/kg body weight daily for 4 weeks. Assessments for neurotoxicity, hepatotoxicity, oxidative stress as well as messenger RNA-expression analysis for Nrf2-antioxidant and pro-inflammatory cytokine genes were conducted. Relative to mice exposed only to acrylamide, co-administration of sulforaphane protected against acrylamide-induced neurotoxic effects such as increase in landing foot spread or decrease in density of noradrenergic axons as well as hepatic necrosis and hemorrhage. Moreover, co-administration of sulforaphane enhanced acrylamide-induced mRNA upregulation of Nrf2 and its downstream antioxidant proteins and suppressed acrylamide-induced mRNA upregulation of tumor necrosis factor alpha (TNF-α) and inducible nitric oxide synthase (iNOS) in the cerebral cortex. The results demonstrate that activation of the Nrf2 signaling pathway by co-treatment of sulforaphane provides protection against acrylamide-induced neurotoxicity through suppression of oxidative stress and inflammation. Nrf2 remains an important target for the strategic prevention of acrylamide-induced neurotoxicity.

scholarly journals Melatonin Promotes In Vitro Maturation of Vitrified-Warmed Mouse Germinal Vesicle Oocytes, Potentially by Reducing Oxidative Stress through the Nrf2 Pathway

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2324
Author(s):  
Shichao Guo ◽  
Jinyu Yang ◽  
Jianpeng Qin ◽  
Izhar Hyder Qazi ◽  
Bo Pan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
In Vitro Maturation ◽  
Germinal Vesicle ◽  
Melatonin Receptors ◽  
Development Rates ◽  
Nrf2 Signaling Pathway ◽  
Mouse Gv Oocytes ◽  
Intracellular Oxidative Stress

Previously it was reported that melatonin could mitigate oxidative stress caused by oocyte cryopreservation; however, the underlying molecular mechanisms which cause this remain unclear. The objective was to explore whether melatonin could reduce oxidative stress during in vitro maturation of vitrified-warmed mouse germinal vesicle (GV) oocytes through the Nrf2 signaling pathway or its receptors. During in vitro maturation of vitrified-warmed mouse GV oocytes, there were decreases (p < 0.05) in the development rates of metaphase I (MI) oocytes and metaphase II (MII) and spindle morphology grades; increases (p < 0.05) in the reactive oxygen species (ROS) levels; and decreases (p < 0.05) in expressions of Nrf2 signaling pathway-related genes (Nrf2, SOD1) and proteins (Nrf2, HO-1). However, adding 10−7 mol/L melatonin to both the warming solution and maturation solutions improved (p < 0.05) these indicators. When the Nrf2 protein was specifically inhibited by Brusatol, melatonin did not increase development rates, spindle morphology grades, genes, or protein expressions, nor did it reduce vitrification-induced intracellular oxidative stress in GV oocytes during in vitro maturation. In addition, when melatonin receptors were inhibited by luzindole, the ability of melatonin to scavenge intracellular ROS was decreased, and the expressions of genes (Nrf2, SOD1) and proteins (Nrf2, HO-1) were not restored to control levels. Therefore, we concluded that 10−7 mol/L melatonin acted on the Nrf2 signaling pathway through its receptors to regulate the expression of genes (Nrf2, SOD1) and proteins (Nrf2, HO-1), and mitigate intracellular oxidative stress, thereby enhancing in vitro development of vitrified-warmed mouse GV oocytes.

scholarly journals Protective Effects of 6,7,4′-Trihydroxyflavanone on Hypoxia-Induced Neurotoxicity by Enhancement of HO-1 through Nrf2 Signaling Pathway

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 341 ◽  
Author(s):  
Hyun-Su Lee ◽  
Gil-Saeng Jeong
Keyword(s):  
Signaling Pathway ◽  
Neurodegenerative Disorders ◽  
Nuclear Translocation ◽  
Protoporphyrin Ix ◽  
Protective Role ◽  
Osteoclast Formation ◽  
Protective Effects ◽  
Protein Levels ◽  
Nrf2 Signaling Pathway ◽  
Pre Treatment

Since hypoxia-induced neurotoxicity is one of the major causes of neurodegenerative disorders, including the Alzheimer’s disease, continuous efforts to find a novel antioxidant from natural products are required for public health. 6,7,4′-trihydroxyflavanone (THF), isolated from Dalbergia odorifera, has been shown to inhibit osteoclast formation and have an antibacterial activity. However, no evidence has reported whether THF has a protective role against hypoxia-induced neurotoxicity. In this study, we found that THF is not cytotoxic, but pre-treatment with THF has a cytoprotective effect on CoCl2-induced hypoxia by restoring the expression of anti-apoptotic proteins in SH-SY5y cells. In addition, pre-treatment with THF suppressed CoCl2-induced hypoxia-related genes including HIF1α, p53, VEGF, and GLUT1 at the mRNA and protein levels. Pre-treatment with THF also attenuated the oxidative stress occurred by CoCl2-induced hypoxia by preserving antioxidant proteins, including SOD and CAT. We revealed that treatment with THF promotes HO-1 expression through Nrf2 nuclear translocation. An inhibitor assay using tin protoporphyrin IX (SnPP) confirmed that the enhancement of HO-1 by pre-treatment with THF protects SH-SY5y cells from CoCl2-induced neurotoxicity under hypoxic conditions. Our results demonstrate the advantageous effects of THF against hypoxia-induced neurotoxicity through the HO-1/Nrf2 signaling pathway and provide a therapeutic insight for neurodegenerative disorders.

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