scholarly journals Clusterin Protects Against Cr(VI)-Induced Oxidative Stress-Associated Hepatotoxicity By Mediating The Akt-Keap1-Nrf2 Signaling Pathway

2021 ◽  
Author(s):  
Yu Ma ◽  
Siwen Li ◽  
Sixuan Tang ◽  
Shuzi Ye ◽  
Ningjuan Liang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Environmental Pollutant ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Nuclear Factor ◽  
Oxygen Species ◽  
Intervention Measures ◽  
Exposed Population ◽  
Nrf2 Signaling Pathway

Abstract Hexavalent chromium [Cr(VI)] is a serious environmental pollutant and threatens human health. Although it has been confirmed that oxidative stress is the main mechanism of liver injury caused by Cr(VI) exposure, the related toxic target and effective intervention measures have not been found. Clusterin (CLU) is an acute phase response protein with cytoprotective and apoptosis delaying effects, and its expression has been confirmed to increase significantly after exposure to Cr(VI). In this study, we demonstrate that CLU acts on the Protein Kinase B (PKB/Akt)-Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor E2-related factor 2 (Nrf2) signaling pathway to release Nrf2 into the nucleus. This to initiates the expression of a downstream protein, heme oxygenase 1 (HO-1), thereby attenuating the ubiquitination ability of Keap1 with Nrf2. We also demonstrated that CLU can affect oxidative stress through the Akt/Nrf2 pathway, which reduces the production of reactive oxygen species (ROS) induced by Cr(VI) and protects against Cr(VI)-induced oxidative stress-associated hepatotoxicity. This study demonstrates a the mechanism of Cr(VI)-induced hepatotoxicity, and indicates that CLU as an intervention target of oxidative stress can provide valuable experimental basis for the prevention and treatment of occupational diseases in Cr(VI)-exposed population.

scholarly journals Cytoprotective Effect of Ligustrum robustum Polyphenol Extract against Hydrogen Peroxide-Induced Oxidative Stress via Nrf2 Signaling Pathway in Caco-2 Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jiayi Chen ◽  
Fangting He ◽  
Sijing Liu ◽  
Tao Zhou ◽  
Saira Baloch ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Signaling Pathway ◽  
Total Phenolic ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Cytoprotective Effect ◽  
Quinone Oxidoreductase ◽  
Antioxidant Genes ◽  
Nrf2 Signaling Pathway

Ligustrum robustum is a traditional herbal tea that is widely distributed in southwest China. The health effects of L. robustum are characteristics of clearing heat, antioxidant, inducing resurgence, and improving digestion. However, the molecular mechanisms related to these effects, particularly the antioxidant mechanism, have been seldom reported. The objective of this study was to assess antioxidative capacity of L. robustum, and its protective effects and mechanisms against hydrogen peroxide (H2O2) - induced toxicity in Caco-2 cells. Total phenolic contents, free radical scavenging activity, and reducing capacity of L. robustum were measured. The effects of L. robustum on the cell viability and antioxidant defense system were explored. The expression of nuclear factor E2 related factor 2 (Nrf2) and antioxidant genes: quinone oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1), and glutamate cysteine ligase (GCL) were analyzed by western blot and qPCR. Pretreatment of L. robustum could significantly reduce H2O2-induced toxicity, decrease the level of reactive oxygen species (ROS) and malondialdehyde (MDA), and increase the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione reductase (GR). By activating the expression of Nrf2 and antioxidant genes (NQO1, HO-1, and GCL), L. robustum exerts cytoprotective effect in Caco-2 cells dealt with H2O2. Therefore, the well-established model of Caco-2 cells demonstrates that L. robustum may modulate the cytoprotective effect against the H2O2-induced oxidative stress through the Nrf2 signaling pathway.

The Effects of Naringin on Cigarette Smoke-Induced Dynamic Changes in Oxidation/Antioxidant System in Lung of Mice

2020 ◽  
Vol 15 (8) ◽  
pp. 1934578X2094723
Author(s):  
Pan Chen ◽  
Ziting Xiao ◽  
Hao Wu ◽  
Yonggang Wang ◽  
Weiwei Su ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Cigarette Smoke ◽  
Antioxidant System ◽  
Antioxidant Systems ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Dynamic Changes ◽  
Tnf Α ◽  
Nrf2 Signaling Pathway

Naringin possesses strong antioxidative activity and can protect against some respiratory diseases. Oxidative stress is thought to be a major factor in the development of many tobacco-caused diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway plays a critical role in the regulation of oxidative stress. The dynamic changes in the antioxidant system in the lung that are induced by cigarette smoke (CS) are not well investigated, and how naringin affects these changes remains unknown. This study aimed to investigate the dynamic changes between the oxidation and antioxidant systems resulting from CS exposure and the effects of naringin on these changes in mice. Mice were chronically exposed to CS for 30 days. The levels of malondialdehyde (MDA), glutathione (GSH), interleukin (IL)-6, and tumor necrosis factor-alpha (TNF-α); the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px); and the expressions of Nrf2, heme oxygenase-1 (HO-1), and nicotinamide adenine dinucleotide phosphate quinone dehydrogenase 1 (NQO1) in lung tissue were measured on days 2, 7, and 30. The levels of MDA, GSH, IL-6, and TNF-α in the lung were found to increase throughout the exposure. SOD and GSH-Px activities showed an increase on day 2 and a decrease on days 7 and 30. The messenger ribonucleic acid expressions of Nrf2, HO-1, and NQO1 were elevated on day 2 and decreased on day 7; Nrf2 and HO-1 expressions were continually decreased, but NQO1 expression was increased again, on day 30. Naringin restored the levels of these biochemical indices to normal throughout the experiment, suggesting that naringin protected against the CS-induced oxidative damage by suppressing the increase of antioxidants resulting from the early stage of CS exposure, as well as inhibiting the depletion of antioxidants due to long-term oxidative stress. Naringin also suppressed lung inflammation by inhibiting IL-6 and TNF-α. These results indicate that naringin possesses a powerful ability to maintain the balance of the oxidation/antioxidant system in the lung when subjected to CS exposure, probably by regulating the Nrf2 signaling pathway.

scholarly journals Mogroside V Alleviates Lipopolysaccharide-Induced Neuroinflammation via Inhibition of TLR4-MyD88 and Activation of AKT/AMPK-Nrf2 Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yuanyuan Liu ◽  
Boxi Zhang ◽  
Jiahe Liu ◽  
Chunyu Qiao ◽  
Nianyu Xue ◽  
...  
Keyword(s):  
Nervous System ◽  
Protein Kinase ◽  
Signaling Pathway ◽  
Neuronal Damage ◽  
Neurological Diseases ◽  
High Mobility ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Nuclear Factor ◽  
Nrf2 Signaling Pathway

As innate immune effector cells in the central nervous system (CNS), microglia not only are essential for the normal development of nervous system but also act on different neurological diseases, including Alzheimer’s disease (AD), Huntington's disease (HD), and other neuroinflammatory diseases. Mogroside V (Mog), a natural plant active ingredient and isolated form of Momordica grosvenori, has been shown to possess anti-inflammatory action, but few studies were carried out to investigate the effects of Mog on neuroinflammation. This study aimed to investigate the role of Mog in lipopolysaccharide- (LPS-) induced neuroinflammation and neuronal damage, revealing the underlying mechanisms. Our data indicated that Mog significantly inhibited the LPS-induced production of proinflammatory factors, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-18, IL-6, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and high mobility group box 1 (HMGB1) in BV-2 cells. We found that Mog also suppressed toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), the phosphorylation of mitogen-activated protein kinases (MAPKs), adenosine 5′-monophosphate- (AMP-) activated protein kinase (AMPK), nuclear factor kappa-B (NF-κB), and protein kinase B (AKT). Moreover, Mog also enhanced the expression of γ-glutamyl cysteine synthetase catalytic subunit (GCLC), modifier subunit (GCLM), heme oxygenase-1 (HO-1), and quinine oxidoreductase 1 (NQO1) proteins, mostly depending on the nuclear translation of nuclear factor erythroid-2 related factor 2 (Nrf2). In contrast, pretreatment with inhibitors of AKT can suppress the phosphorylation of AMPK, Nrf2, and its downstream proteins expression. In summary, Mog might play a protective role against LPS-induced neurotoxicity by inhibiting the TLR4-MyD88 and activation of AMPK/AKT-Nrf2 signaling pathway.

1-Bromopropane-induced apoptosis in OVCAR-3 cells via oxidative stress and inactivation of Nrf2

2020 ◽  
pp. 074823372097942
Author(s):  
Guangtao Yang ◽  
Yingping Xiang ◽  
Wei Zhou ◽  
Xiaohuan Zhong ◽  
Yanfang Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Reproductive Toxicity ◽  
Antioxidant Vitamin ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Ovarian Carcinoma Cell Line ◽  
Nrf2 Signaling Pathway ◽  
Induced Apoptosis

The bromoalkane, 1-bromopropane (1-BP), may damage the reproductive system though oxidative stress, while the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) plays an important role in regulating intracellular antioxidant levels against oxidative stress. This study explored the role of oxidative stress and the Nrf2 signaling pathway in mediating the reproductive toxicity of 1-BP using the ovarian carcinoma cell line OVCAR-3 as an in vitro model of the human ovary. OVCAR-3 cells were treated with 1, 5, 10 and 15 mM 1-BP. After 24 h, the cellular reactive oxygen species and malondialdehyde concentrations significantly increased, while the superoxide dismutase activity decreased; translocation of Nrf2 from the cytosol to the nucleus as well as downstream protein expression of Nrf2-regulated genes heme oxygenase-1 and Bcl-2 was inhibited. Apoptosis was also observed, accompanied by increased caspase-3 and caspase-9 activity. The antioxidant vitamin C alleviated 1-BP-induced apoptosis by inhibiting caspase activity activating the Nrf2 signaling pathway. These findings suggested that 1-BP induced oxidative stress and apoptosis in OVCAR-3 cells through inactivation of Nrf2 signaling.

scholarly journals N-acetylcysteine alleviates PCB52-induced hepatotoxicity by repressing oxidative stress and inflammatory responses

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9720
Author(s):  
Wen-Tao Zhou ◽  
Li-Bin Wang ◽  
Hao Yu ◽  
Kai-Kai Zhang ◽  
Li-Jian Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Viability ◽  
Inflammatory Responses ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Nuclear Factor ◽  
Oxygen Species ◽  
Nrf2 Pathway ◽  
Protein Levels ◽  
Saline Pretreatment

Polychlorinated biphenyls (PCBs), particularly low chlorinated congeners in our environment, can induce human hepatotoxicity. However, the mechanisms by which PCBs cause hepatotoxicity remain elusive. Moreover, there are no effective treatments for this condition. In this study, 40 μM PCB52 was administered to rat (Brl-3A) and human hepatocytes (L-02) for 48 h following the N-acetylcysteine (NAC)/saline pretreatment. A significant decrease in cell viability was observed in PCB52-treated cells relative to the control. Besides, PCB52 significantly increased reactive oxygen species (ROS) levels and malondialdehyde (MDA) contents, suggesting induction of oxidative stress. The expression of Traf6, MyD88, and Tnf in Brl-3A cells and that of MYD88, TNF, and IL1B in L-02 cells were significantly upregulated by PCB52. Consistently, overexpression of TLR4, MyD88, Traf6, and NF-κB p65 proteins was observed in PCB52-treated cells, indicating activation of inflammatory responses. Nevertheless, no changes in kelch-like ECH-associated protein 1 (keap1), nuclear factor-erythroid 2-related factor (nrf2), and heme oxygenase-1 proteins were observed in PCB52-treated cells, indicating non-activation of the keap1/nrf2 pathway. Pretreatment with NAC significantly ameliorated PCB52 effects on cell viability, ROS levels, MDA contents and expression of inflammatory elements at both RNA and protein levels. However, no changes in keap1, nrf2 and HO-1 protein levels were detected following NAC pretreatment. Taken together, with non-activated keap1/nrf2 pathway, PCB52-induced oxidative stress and inflammatory responses could be responsible for its hepatotoxicity. These effects were effectively attenuated by NAC pretreatment, which scavenges ROS and dampens inflammatory responses. This study might provide novel strategies for the treatment of the PCBs-associated hepatotoxic effects.

scholarly journals Cardamonin Attenuates Inflammation and Oxidative Stress in Interleukin-1β-Stimulated Osteoarthritis Chondrocyte through the Nrf2 Pathway

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 862
Author(s):  
Yi-Jen Peng ◽  
Jeng-Wei Lu ◽  
Chian-Her Lee ◽  
Herng-Sheng Lee ◽  
You-Hsiang Chu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Signaling Pathway ◽  
Antioxidant Properties ◽  
Joint Disease ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Nrf2 Signaling Pathway ◽  
Antioxidant Proteins ◽  
And Oxidative Stress

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by the deterioration of articular cartilage. The progression of OA leads to an increase in inflammatory mediators in the joints, thereby promoting the destruction of the cartilage matrix. Recent studies have reported on the anti-inflammatory and antioxidant properties of cardamonin, which also appears to interact with cellular targets, such as nuclear erythroid 2-related factor 2 (Nrf2), extracellular signal-regulated kinase (ERK), and mammalian target of rapamycin (mTOR) during the progression of tumors. To date, few studies have investigated the effects of cardamonin on chondrocyte inflammation. In the current study, we determined that treating interleukin-1 beta (IL-1β-stimulated chondrocyte cells) with cardamonin significantly reduced the release of nitric oxide (NO) and prostaglandin E2 (PGE2) and significantly inhibited the expression of pro-inflammatory proteins, including inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2). Cardamonin was also shown to: (1) inhibit the activation and production of matrix metalloproteinases (MMPs), (2) suppress the nuclear factor-κB (NF-κB) signaling pathway, (3) suppress the expression of toll-like receptor proteins, (4) activate the Nrf2 signaling pathway, and (5) increase the levels of antioxidant proteins heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1). The increase in antioxidant proteins led to corresponding antioxidant effects (which were abolished by Nrf2 siRNA). Our findings identify cardamonin as a candidate Nrf2 activator for the treatment and prevention of OA related to inflammation and oxidative stress.

scholarly journals Prodigiosin Promotes Nrf2 Activation to Inhibit Oxidative Stress Induced by Microcystin-LR in HepG2 Cells

Toxins ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 403 ◽  
Author(s):  
Jihua Chen ◽  
Yuji Li ◽  
Fuqiang Liu ◽  
De-Xing Hou ◽  
Jingjing Xu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hepg2 Cells ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Nuclear Factor ◽  
Oxygen Species ◽  
Anticancer Properties ◽  
Nrf2 Activation ◽  
Nrf2 Protein ◽  
Related Phase

Microcystin-LR (MC-LR), a cyanotoxin produced by cyanobacteria, induces oxidative stress in various types of cells. Prodigiosin, a red linear tripyrrole pigment, has been recently reported to have antimicrobial, antioxidative, and anticancer properties. How prodigiosin reacts to reactive oxygen species (ROS) induced by MC-LR is still undetermined. This study aimed to examine the effect of prodigiosin against oxidative stress induced by MC-LR in HepG2 cells. Ros was generated after cells were treated with MC-LR and was significantly inhibited with treatment of prodigiosin. In prodigiosin-treated cells, the levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and Nrf2-related phase II enzyme heme oxygenase-1 (HO-1) were increased. Besides, prodigiosin contributed to enhance nuclear Nrf2 level and repressed ubiquitination. Furthermore, prodigiosin promoted Nrf2 protein level and inhibited ROS in Nrf2 knocked down HepG2 cells. Results indicated that prodigiosin reduced ROS induced by MC-LR by enhancing Nrf2 translocation into the nucleus in HepG2 cells. The finding presents new clues for the potential clinical applications of prodigiosin for inhibiting MC-LR-induced oxidative injury in the future.

scholarly journals Phillyrin Mitigates Apoptosis and Oxidative Stress in Hydrogen Peroxide-Treated RPE Cells through Activation of the Nrf2 Signaling Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Yuanyuan Du ◽  
Longtai You ◽  
Boran Ni ◽  
Na Sai ◽  
Wenping Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Signaling Pathway ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Apoptosis Pathway ◽  
Rpe Cells ◽  
Nrf2 Signaling Pathway

Oxidative stress-induced dysfunction or apoptosis in retinal pigment epithelial (RPE) cells is an important cause of dry age-related macular degeneration (AMD). Although phillyrin has been shown to exert significant antioxidant effects, the underlying mechanism of action remains unclear. The purpose of this study was to investigate the protective effect of phillyrin on hydrogen peroxide- (H2O2-) induced oxidative stress damage in RPE cells and the potential mechanism involved. It was found that phillyrin significantly protected RPE cells from H2O2 cytotoxicity. Furthermore, phillyrin alleviated oxidative stress-induced apoptosis via inhibition of endogenous and exogenous apoptotic pathways. Compared with the H2O2-treated group, the expressions of cleaved caspase-3, cleaved caspase-9, cleaved polymerase (PARP), death receptor Fas, and cleaved caspase-8, as well as Bax/Bcl-2 ratio were decreased in RPE cells after the phillyrin intervention. In addition, phillyrin reversed the oxidative stress-induced reductions in superoxide dismutase (SOD) and glutathione (GSH) levels and annulled the elevations in reactive oxygen species (ROS) and malondialdehyde (MDA), thereby restoring oxidant-antioxidant homeostasis. Phillyrin treatment upregulated the expressions of cyclin E, cyclin-dependent kinase 2 (CDK2), and cyclin A and downregulated the expressions of p21 and p-p53, thereby reversing the G0/G1 cell cycle arrest in H2O2-treated RPE cells. Pretreatment with phillyrin also increased the expressions of nuclear factor-erythroid 2-related factor 2 (Nrf2), total Nrf2, heme oxygenase-1 (HO-1), and NAD(P)H: quinone oxidoreductases-1 (NQO-1) in RPE cells and inhibited the formation of Kelch-like ECH-associated protein 1 (Keap1)/Nrf2 protein complex. Thus, phillyrin effectively protected RPE cells from oxidative stress through activation of the Nrf2 signaling pathway and inhibition of the mitochondria-dependent apoptosis pathway.

scholarly journals Quercetin Protects against Lipopolysaccharide-Induced Intestinal Oxidative Stress in Broiler Chickens through Activation of Nrf2 Pathway

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1053 ◽  
Author(s):  
Lei Sun ◽  
Gaoqing Xu ◽  
Yangyunyi Dong ◽  
Meng Li ◽  
Lianyu Yang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Superoxide Dismutase ◽  
Signaling Pathway ◽  
Broiler Chickens ◽  
Mapk Pathway ◽  
Basal Diet ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Nrf2 Signaling Pathway

We investigated the potential ability of quercetin to protect against lipopolysaccharide (LPS)-induced intestinal oxidative stress in broiler chickens and the potential role of the Nrf2 (nuclear factor erythroid 2-related factor 2) signaling pathway. One-day-old broiler chickens (n = 240) were randomized into four groups: saline-challenged broiler chickens fed a basal diet (Con), LPS-challenged broiler chickens on a basal diet (LPS), and LPS-treated broiler chickens on a basal diet containing either 200 or 500 mg/kg of quercetin (Que200+LPS or Que500+LPS). Quercetin (200 mg/kg) significantly alleviated LPS-induced decreased duodenal, jejunal, and illeal villus height and increased the crypt depth in these regions. Quercetin significantly inhibited LPS-induced jejunal oxidative stress, including downregulated reactive oxygen species (ROS), malondialdehyde (MDA), and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels, and it upregulated superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels. Quercetin relieved LPS-induced jejunal mitochondria damage and upregulated mitochondrial DNA copy number-related gene expression, including cytochrome c oxidase subunit 1 (COX1), ATP synthase F0 subunit 6 (ATP6), and NADH dehydrogenase subunit 1 (ND1). Quercetin attenuated the LPS-induced inhibition of Nrf2 activation, translocation, and downstream gene expression, including heme oxygenase-1 (HO-1), NAD (P) H dehydrogenase quinone 1 (NQO1), and manganese superoxide dismutase (SOD2). Additionally, quercetin attenuated the LPS-inhibition of c-Jun N-terminal kinase (JNK), Extracellular Regulated protein Kinases (ERK), and p38MAPK (p38) phosphorylation in the MAPK pathway. Thus, quercetin attenuated LPS-induced oxidative stress in the intestines of broiler chickens via the MAPK/Nrf2 signaling pathway.

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