scholarly journals Long Noncoding RNA ANPODRT Overexpression Protects Nucleus Pulposus Cells from Oxidative Stress and Apoptosis by Activating Keap1-Nrf2 Signaling

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Liang Kang ◽  
Yueyang Tian ◽  
Xing Guo ◽  
Xu Chu ◽  
Yuan Xue
Keyword(s):  
Oxidative Stress ◽  
Nucleus Pulposus ◽  
Noncoding Rna ◽  
Target Genes ◽  
Nuclear Translocation ◽  
Related Factor ◽  
Nucleus Pulposus Cells ◽  
Tert Butyl Hydroperoxide ◽  
Antioxidative Stress ◽  
Opposing Effects

Oxidative stress and subsequent nucleus pulposus (NP) cell apoptosis are important contributors to the development of intervertebral disc degeneration (IDD). Emerging evidences show that long noncoding RNAs (lncRNAs) play a role in the pathogenesis of IDD. In this study, we investigated the role of lncRNA ANPODRT (anti-NP cell oxidative damage-related transcript) in oxidative stress and apoptosis in human NP cells. We found that ANPODRT was downregulated in degenerative NP tissues and in NP cells treated with tert-butyl hydroperoxide (TBHP, the oxidative stress inducer). ANPODRT overexpression alleviated oxidative stress and apoptosis in NP cells exposed to TBHP, while ANPODRT knockdown exerted opposing effects. Mechanistically, ANPODRT facilitated nuclear factor E2-related factor 2 (Nrf2) accumulation and nuclear translocation and activated its target genes by disrupting the kelch-like ECH-associated protein 1- (Keap1-) Nrf2 association in NP cells. Nrf2 knockdown abolished the antioxidative stress and antiapoptotic effects of ANPODRT in NP cells treated with TBHP. Collectively, our findings suggest that ANPODRT protects NP cells from oxidative stress and apoptosis, at least partially, by activating Nrf2 signaling, implying that ANPODRT may be a potential therapeutic target for IDD.

scholarly journals Pterostilbene inhibits inflammation by promoting the nuclear translocation of Nrf2 in the rat nucleus pulposus

2018 ◽  
Vol 16 ◽  
pp. 1721727X1875653
Author(s):  
Soo-Min Lee ◽  
Li-Yan Jiao ◽  
Li-Bo Jiang ◽  
Shu-Hao Liu ◽  
Maka Lee ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nucleus Pulposus ◽  
Messenger Rna ◽  
Nuclear Translocation ◽  
Cell Counting ◽  
Enzyme Linked Immunosorbent Assay ◽  
Related Factor ◽  
Nucleus Pulposus Cells ◽  
Cox 2 ◽  
Anti Inflammatory

Pterostilbene (PTE), a natural plant extract, has an anti-inflammatory effect; however, whether PTE could protect nucleus pulposus cells (NPCs) in the intervertebral disk from inflammation remains unclear. Primary NPCs isolated from Sprague-Dawley (SD) rats were cultured, and Cell Counting Kit-8 (CCK-8) analysis was used to test the cytotoxicity of PTE. The effect of PTE on interleukin-1β (IL-1β)-induced inflammation was analyzed using an enzyme-linked immunosorbent assay, real-time polymerase chain reaction (PCR), and a Griess test. Western blotting, immunofluorescence, and a nuclear factor erythroid 2-related factor 2 (Nrf2) small interfering RNA (siRNA) transfection were used to assess the involvement of Nrf2 in the anti-inflammatory mechanism of PTE on NPCs. The results of the CCK-8 analysis showed that PTE produced no cytotoxicity in NPCs at 20 μM for 24 h. PTE suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2) and inhibited the messenger RNA (mRNA) expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) induced by IL-1β. PTE could promote the nuclear translocation of Nrf2 in NPCs. In addition, Nrf2 silence reversed the inhibitory effect of PTE on the production of NO and PGE2 and the expression of COX-2 and iNOS. These results indicate that PTE inhibits inflammation in the rat nucleus pulposus by promoting the nuclear translocation of Nrf2.

Liraglutide Ameliorates Lipotoxicity-Induced Oxidative Stress by Activating the NRF2 Pathway in HepG2 Cells

2020 ◽  
Vol 52 (07) ◽  
pp. 532-539 ◽  
Author(s):  
Chong-gui Zhu ◽  
Ying Luo ◽  
Hao Wang ◽  
Jun-Yi Li ◽  
Jie Yang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Enzymes ◽  
Mrna Expression ◽  
Hepg2 Cells ◽  
Target Genes ◽  
Nuclear Translocation ◽  
Thiobarbituric Acid ◽  
Related Factor ◽  
Protective Effects ◽  
Alcoholic Fatty Liver

AbstractAlthough glucagon-like peptide-1 (GLP-1) analogue has been reported to suppress oxidative stress in non-alcoholic fatty liver disease (NAFLD), an effective therapeutic agent for NAFLD is currently unavailable. Therefore, in this study, we aimed to investigate the protective effects of the GLP-1 analogue liraglutide against lipotoxicity-induced oxidative stress in HepG2 cells and to elucidate the underlying mechanisms. HepG2 cells were cultured for 48 hours and treated with a free fatty acid (FFA) mixture: FFA mixture and liraglutide or FFA mixture, liraglutide, and exendin (9–39). Lipid accumulation was examined by oil red O staining. Oxidative stress was assessed by measuring the levels of intracellular reactive oxygen species using 2′,7′-dichlorofluorescein diacetate and thiobarbituric acid-reactive substances, whereas antioxidant capacity was assessed by measuring the activity of superoxide dismutase and catalase. Expression of the nuclear factor erythroid-2-related factor 2 (NRF2) gene and the genes encoding antioxidant enzymes was analyzed using quantitative RT-PCR. Cellular and nuclear NRF2 expression levels were assessed using immunofluorescence cell staining and western blotting. Liraglutide treatment reduced high fat-induced lipid formation and the levels of oxidative stress markers and increased antioxidant enzyme activity in HepG2 cells. Liraglutide treatment increased the mRNA expression of NRF2 target genes, induced NRF2 nuclear translocation, and increased nuclear NRF2 levels without altering NRF2 mRNA expression. Collectively, these results indicate that liraglutide exhibits a protective effect against lipotoxicity-induced oxidative stress, possibly via modulation of NRF2 and expression of antioxidant enzymes in liver cells.

scholarly journals Protective Effects of GYY4137 on Renal Ischaemia/Reperfusion Injury through Nrf2-Mediated Antioxidant Defence

2021 ◽  
pp. 1-9
Author(s):  
Hongmei Zhao ◽  
Yun Qiu ◽  
Yichen Wu ◽  
Hong Sun ◽  
Sumin Gao
Keyword(s):  
Oxidative Stress ◽  
Reperfusion Injury ◽  
Nuclear Translocation ◽  
Organ Damage ◽  
Related Factor ◽  
Protective Effects ◽  
Ischaemia Reperfusion Injury ◽  
Renal Ischaemia ◽  
Ischaemia Reperfusion ◽  
Renal Histology

<b><i>Introduction/Aims:</i></b> Hydrogen sulfide (H<sub>2</sub>S) is considered to be the third most important endogenous gasotransmitter in organisms. GYY4137 is a long-acting donor for H<sub>2</sub>S, a gas transmitter that has been shown to prevent multi-organ damage in animal studies. We previously reported the effect of GYY4137 on cardiac ischaemia reperfusion injury (IRI) in diabetic mice. However, the role and mechanism of GYY4137 in renal IRI are poorly understood. The aims of this study were to determine whether GYY4137 can effectively alleviate the injury induced by renal ischaemia reperfusion and to explore its possible mechanism. <b><i>Methods:</i></b> Mice received right nephrectomy and clipping of the left renal pedicle for 45 min. GYY4137 was administered by intraperitoneal injection for 2 consecutive days before the operation. The model of hypoxia/reoxygenation injury was established in HK-2 cells, which were pre-treated with or without GYY4137. Renal histology, function, apoptosis, and oxidative stress were measured. Western blot was used to measure the target ­protein after renal IRI. <b><i>Results:</i></b> The results indicated that GYY4137 had a clear protective effect on renal IRI as reflected by the attenuation of renal dysfunction, renal tubule injury, and apoptosis. Moreover, GYY4137 remarkably reduced renal IRI-induced oxidative stress. GYY4137 significantly elevated the nuclear translocation of nuclear factor-erythroid-2-related factor 2 (Nrf2) and the expression of antioxidant enzymes regulated by Nrf2, including SOD, HO-1, and NQO-1. <b><i>Conclusions:</i></b> GYY4137 alleviates ischaemia reperfusion-induced renal injury through activating the antioxidant effect mediated by Nrf2 signalling.

scholarly journals Keap1 deletion accelerates mutant K-ras/p53-driven cholangiocarcinoma

2020 ◽  
Vol 318 (3) ◽  
pp. G419-G427 ◽  
Author(s):  
Tatsuhide Nabeshima ◽  
Shin Hamada ◽  
Keiko Taguchi ◽  
Yu Tanaka ◽  
Ryotaro Matsumoto ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cancer Progression ◽  
Stress Responses ◽  
Target Genes ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Related Factor ◽  
Loss Of Function ◽  
P53 Expression ◽  
Nrf2 Activation

The activation of the Kelch-like ECH-associated protein 1 (Keap1)-NF-E2-related factor 2 (Nrf2) pathway contributes to cancer progression in addition to oxidative stress responses. Loss-of-function Keap1 mutations were reported to activate Nrf2, leading to cancer progression. We examined the effects of Keap1 deletion in a cholangiocarcinoma mouse model using a mutant K-ras/ p53 mouse. Introduction of the Keap1 deletion into liver-specific mutant K-ras/ p53 expression resulted in the formation of invasive cholangiocarcinoma. Comprehensive analyses of the gene expression profiles identified broad upregulation of Nrf2-target genes such as Nqo1 and Gstm1 in the Keap1-deleted mutant K-ras/ p53 expressing livers, accompanied by upregulation of cholangiocyte-related genes. Among these genes, the transcriptional factor Sox9 was highly expressed in the dysplastic bile duct. The Keap-Nrf2-Sox9 axis might serve as a novel therapeutic target for cholangiocarcinoma. NEW & NOTEWORTHY The Keap1-Nrf2 system has a wide variety of effects in addition to the oxidative stress response in cancer cells. Addition of the liver-specific Keap1 deletion to mice harboring mutant K-ras and p53 accelerated cholangiocarcinoma formation, together with the hallmarks of Nrf2 activation. This process involved the expansion of Sox9-positive cells, indicating increased differentiation toward the cholangiocyte phenotype.

scholarly journals Human Bone Marrow Mesenchymal Stromal Cell-Derived Extracellular Vesicles Promote Proliferation of Degenerated Nucleus Pulposus Cells and the Synthesis of Extracellular Matrix Through the SOX4/Wnt/β-Catenin Axis

2021 ◽  
Vol 12 ◽  
Author(s):  
Haoyu Wang ◽  
Fei Li ◽  
Wenrui Ban ◽  
Jing Zhang ◽  
Guiqi Zhang
Keyword(s):  
Extracellular Matrix ◽  
Nucleus Pulposus ◽  
Extracellular Vesicles ◽  
Target Genes ◽  
Intervertebral Disk ◽  
Human Bone ◽  
Nucleus Pulposus Cells ◽  
Synthetic Genes ◽  
Downstream Target ◽  
Transcription Factor 4

Objective: Intervertebral disk degeneration (IDD) is a major cause of pain in the back, neck, and radiculus. Mesenchymal stem cells (MSCs)-derived extracellular vesicles (EVs) are therapeutic in musculoskeletal degenerative diseases such as IDD. This study explored the effect and functional mechanism of human bone MSCs (hBMSCs)-derived EVs in proliferation and apoptosis of degenerated nucleus pulposus cells (DNPCs) and extracellular matrix (ECM) synthesis.Methods: Extracellular vesicles were isolated from hBMSCs and identified. DNPCs were induced by TNF-α. EVs were incubated with DNPCs for 24h. Internalization of EVs by DNPCs, DNPCs proliferation, apoptosis, and expressions of ECM synthetic genes, degrading genes and miR-129-5p were assessed. Downstream target genes of miR-129-5p were predicted. Target relation between miR-129-5p and SRY-box transcription factor 4 (SOX4) was verified. DNPCs proliferation, apoptosis, and ECM synthesis were measured after treatment with EVs and miR-129-5p inhibitor or SOX4 overexpression. Expressions of SOX4 and Wnt/β-catenin pathway-related proteins were determined.Results: hBMSC-EVs promoted DNPCs proliferation, inhibited apoptosis, increased expressions of ECM synthetic genes, and reduced expressions of ECM degrading genes. hBMSC-EVs carried miR-129-5p into DNPCs. Silencing miR-129-5p in EVs partially inverted the effect of EVs on DNPCs proliferation and ECM synthesis. miR-129-5p targeted SOX4. SOX4 overexpression annulled the effect of EVs on DNPCs proliferation and ECM synthesis. Expressions of Wnt1 and β-catenin were decreased in EVs-treated DNPCs, while silencing miR-129-5p in EVs promoted expressions of Wnt1 and β-catenin.Conclusion: hBMSC-EVs promoted DNPCs proliferation and ECM synthesis by carrying miR-129-5p into DNPCs to target SOX4 and deactivating the Wnt/β-catenin axis.

Melatonin resists oxidative stress-induced apoptosis in nucleus pulposus cells

Life Sciences ◽  
2018 ◽  
Vol 199 ◽  
pp. 122-130 ◽  
Author(s):  
Ruijun He ◽  
Min Cui ◽  
Hui Lin ◽  
Lei Zhao ◽  
Jiayu Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nucleus Pulposus ◽  
Nucleus Pulposus Cells ◽  
Induced Apoptosis

Effect of fluoride on PERK-Nrf2 signaling pathway in mouse ameloblasts

2019 ◽  
Vol 38 (7) ◽  
pp. 833-845
Author(s):  
X Zhou ◽  
Z Chen ◽  
W Zhong ◽  
R Yu ◽  
L He
Keyword(s):  
Oxidative Stress ◽  
Er Stress ◽  
Signaling Pathway ◽  
Nuclear Import ◽  
Target Genes ◽  
Dental Fluorosis ◽  
Related Factor ◽  
Dependent Manner ◽  
Nrf2 Signaling Pathway ◽  
Glutamylcysteine Synthetase

In the development of dental fluorosis, oxidative stress is considered as the key mechanism. Endoplasmic reticulum (ER) stress can induce oxidative stress and activate the important antioxidative factor nuclear factor erythroid 2-related factor 2 (Nrf2) in a PKR-like ER kinase (PERK)-dependent manner, but combining ER stress and oxidative stress, the role of PERK-Nrf2 signaling pathway involved in fluoride-regulated ameloblasts is not fully defined. Here, we studied the effect of fluoride on PERK-Nrf2 signaling pathway in mouse ameloblasts. We found that low-dose and continuous fluoride exposure increased binding immunoglobulin protein expression and activated PERK–activating transcription factor 4 signaling pathway. Meanwhile, the expression of Nrf2 and its target genes (glutamylcysteine synthetase and glutathione S-transferase-P1) enhanced following ER stress. Tunicamycin increased the expression of PERK, leading to Nrf2 nuclear import, and tauroursodeoxycholate suppressed Nrf2 activation through PERK during ER stress, indicating that PERK activation is required for Nrf2 nuclear entry. Furthermore, tert-butylhydroquinone triggered the overexpression of Nrf2 to reduce ER stress, but luteolin inhibited Nrf2 nuclear localization to elevate ER stress. In summary, this study proved that fluoride under certain dose can induce ER stress and promote Nrf2 nuclear import via PERK activation and suggested that antioxidation mechanism mediated by PERK-Nrf2 can alleviate fluoride-induced ER stress effectively.

scholarly journals Mini-GAGR, an intranasally applied polysaccharide, activates the neuronal Nrf2-mediated antioxidant defense system

2018 ◽  
Vol 293 (47) ◽  
pp. 18242-18269 ◽  
Author(s):  
Kelsey Murphy ◽  
Killian Llewellyn ◽  
Samuel Wakser ◽  
Josef Pontasch ◽  
Natasha Samanich ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant System ◽  
Cortical Neurons ◽  
Hippocampal Neurons ◽  
Nuclear Translocation ◽  
Growth Factor Receptor ◽  
Antioxidant Defense System ◽  
Related Factor ◽  
Dependent Manner ◽  
Amyloid Aβ

Oxidative stress triggers and exacerbates neurodegeneration in Alzheimer's disease (AD). Various antioxidants reduce oxidative stress, but these agents have little efficacy due to poor blood–brain barrier (BBB) permeability. Additionally, single-modal antioxidants are easily overwhelmed by global oxidative stress. Activating nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) and its downstream antioxidant system are considered very effective for reducing global oxidative stress. Thus far, only a few BBB-permeable agents activate the Nrf2-dependent antioxidant system. Here, we discovered a BBB-bypassing Nrf2-activating polysaccharide that may attenuate AD pathogenesis. Mini-GAGR, a 0.7-kDa cleavage product of low-acyl gellan gum, increased the levels and activities of Nrf2-dependent antioxidant enzymes, decreased reactive oxygen species (ROS) under oxidative stress in mouse cortical neurons, and robustly protected mitochondria from oxidative insults. Moreover, mini-GAGR increased the nuclear localization and transcriptional activity of Nrf2 similarly to known Nrf2 activators. Mechanistically, mini-GAGR increased the dissociation of Nrf2 from its inhibitor, Kelch-like ECH-associated protein 1 (Keap1), and induced phosphorylation and nuclear translocation of Nrf2 in a protein kinase C (PKC)- and fibroblast growth factor receptor (FGFR1)-dependent manner. Finally, 20-day intranasal treatment of 3xTg-AD mice with 100 nmol of mini-GAGR increased nuclear p-Nrf2 and growth-associated protein 43 (GAP43) levels in hippocampal neurons, reduced p-tau and β-amyloid (Aβ) peptide–stained neurons, and improved memory. The BBB-bypassing Nrf2-activating polysaccharide reported here may be effective in reducing oxidative stress and neurodegeneration in AD.

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