Geniposide Attenuates Hyperglycemia-Induced Oxidative Stress and Inflammation by Activating the Nrf2 Signaling Pathway in Experimental Diabetic Retinopathy

Geniposide (GEN) is a natural antioxidant and anti-inflammatory product and plays an important role in the treatment of diabetes and diabetic complications. To explore the biological functions and mechanism of GEN in diabetic retinopathy (DR), we constructed the in vitro and in vivo model of DR by using primary cultured mouse retinal Müller cells and C57BL/6 mice, respectively. We found that GEN inhibited ROS accumulation, NF-κB activation, Müller cell activation, and inflammatory cytokine secretion both in vitro and in vivo, which is probably mediated through the Nrf2 pathway. Exendin (9-39) (EX-9), an antagonist of glucagon-like peptide-1 receptor (GLP-1R), abolished the protective effect of GEN on high glucose- (HG-) induced Müller cells. Additionally, GEN decreased hyperglycemia-induced damage to Müller cells and blood-retinal barrier in the retinas of mice with DR. We demonstrated that GEN was capable of protecting Müller cells and mice from HG-induced oxidative stress and inflammation, which is mostly dependent on the Nrf2 signaling pathway through GLP-1R. GEN may be an effective approach for the treatment of DR.

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Dietary Supplement Enriched in Antioxidants and Omega-3 Promotes Glutamine Synthesis in Müller Cells: A Key Process against Oxidative Stress in Retina

Nutrients ◽

10.3390/nu13093216 ◽

2021 ◽

Vol 13 (9) ◽

pp. 3216

Author(s):

Maryvonne Ardourel ◽

Chloé Felgerolle ◽

Arnaud Pâris ◽

Niyazi Acar ◽

Khaoula Ramchani Ben Othman ◽

...

Keyword(s):

Oxidative Stress ◽

Müller Cells ◽

Nutritional Supplement ◽

Glutamine Metabolism ◽

Muller Cells ◽

Omega 3 ◽

Glutamine Synthesis ◽

The Impact

To prevent ocular pathologies, new generation of dietary supplements have been commercially available. They consist of nutritional supplement mixing components known to provide antioxidative properties, such as unsaturated fatty acid, resveratrol or flavonoids. However, to date, only one preclinical study has evaluated the impact of a mixture mainly composed of those components (Nutrof Total®) on the retina and demonstrated that in vivo supplementation prevents the retina from structural and functional injuries induced by light. Considering the crucial role played by the glial Müller cells in the retina, particularly to regulate the glutamate cycle to prevent damage in oxidative stress conditions, we questioned the impact of this ocular supplement on the glutamate metabolic cycle. To this end, various molecular aspects associated with the glutamate/glutamine metabolism cycle in Müller cells were investigated on primary Müller cells cultures incubated, or not, with the commercially mix supplement before being subjected, or not, to oxidative conditions. Our results demonstrated that in vitro supplementation provides guidance of the glutamate/glutamine cycle in favor of glutamine synthesis. These results suggest that glutamine synthesis is a crucial cellular process of retinal protection against oxidative damages and could be a key step in the previous in vivo beneficial results provided by the dietary supplementation.

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Melatonin attenuates oxidative stress and inflammation of Müller cells in diabetic retinopathy via activating the Sirt1 pathway

Biomedicine & Pharmacotherapy ◽

10.1016/j.biopha.2021.111274 ◽

2021 ◽

Vol 137 ◽

pp. 111274

Author(s):

Yuanyuan Tu ◽

E Song ◽

Zhenzhen Wang ◽

Na Ji ◽

Linling Zhu ◽

...

Keyword(s):

Oxidative Stress ◽

Diabetic Retinopathy ◽

Müller Cells ◽

Muller Cells

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

Animals ◽

10.3390/ani11082324 ◽

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.

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Ginsenoside Rg1 protects against acetaminophen-induced liver injury via activating Nrf2 signaling pathway in vivo and in vitro

Regulatory Toxicology and Pharmacology ◽

10.1016/j.yrtph.2018.07.012 ◽

2018 ◽

Vol 98 ◽

pp. 58-68 ◽

Cited By ~ 8

Author(s):

Chenqing Ning ◽

Xiaoguang Gao ◽

Changyuan Wang ◽

Yulong Kong ◽

Zhihao Liu ◽

...

Keyword(s):

Liver Injury ◽

Signaling Pathway ◽

Ginsenoside Rg1 ◽

Nrf2 Signaling Pathway

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Guavinoside B from Psidium guajava alleviates acetaminophen-induced liver injury via regulating the Nrf2 and JNK signaling pathways

Food & Function ◽

10.1039/d0fo01338b ◽

2020 ◽

Vol 11 (9) ◽

pp. 8297-8308

Author(s):

Yuanyuan Li ◽

Jialin Xu ◽

Dongli Li ◽

Hang Ma ◽

Yu Mu ◽

...

Keyword(s):

Liver Injury ◽

Signaling Pathways ◽

Signaling Pathway ◽

Phenolic Compound ◽

Psidium Guajava ◽

Jnk Signaling ◽

Nrf2 Signaling Pathway ◽

Jnk Signaling Pathway

GUB, a main phenolic compound present in guava fruits, could alleviate APAP-induced liver injury in vitro and in vivo by activating the Nrf2 signaling pathway and inhibiting the JNK signaling pathway.

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Notoginsenoside R1 Ameliorates Diabetic Retinopathy through PINK1-Dependent Activation of Mitophagy

Cells ◽

10.3390/cells8030213 ◽

2019 ◽

Vol 8 (3) ◽

pp. 213 ◽

Cited By ~ 15

Author(s):

Ping Zhou ◽

Weijie Xie ◽

Xiangbao Meng ◽

Yadong Zhai ◽

Xi Dong ◽

...

Keyword(s):

Oxidative Stress ◽

Diabetic Retinopathy ◽

Oral Treatment ◽

Müller Cells ◽

Panax Notoginseng ◽

Protective Effects ◽

Muller Cells ◽

Beneficial Effects ◽

Pre Treatment ◽

Lc3 Puncta

: Accumulating evidence has indicated that inflammation, oxidative stress, apoptosis, and autophagy in retinal Müller cells are involved in diabetic retinopathy (DR). Notoginsenoside R1 (NGR1), a novel saponin extracted from Panax notoginseng, posesses pharmacological properties, including treating diabetic encephalopathy and improving microcirculatory disorders. Nevertheless, its beneficial effects on DR and the potential mechanism remain to be elucidated. In this study, we found retinal vascular degeneration, reduced retinal thickness, and impaired retinal function in db/db mice were all dramatically attenuated by oral treatment with NGR1 (30 mg/kg) for 12 weeks. NGR1 pretreatment also significantly inhibited apoptosis, markedly suppressed the VEGF expression, markedly increased PEDF expression and markedly inhibited oxidative stress and inflammation in rat retinal Müller cells (rMC-1) subjected to high glucose (HG) and in the retinas of db/db mice. Furthermore, NGR1 pre-treatment upregulated the level of PINK1 and Parkin, increased the LC3-II/LC3-I ratio, and downregulated the level of p62/SQSTM1 in rMC-1 cells induced by HG and in the retinas of db/db mice. Moreover, NGR1 administration enhanced the co-localization of GFP-LC3 puncta and MitoTracker in rMC-1 cells. Importantly, knockdown of PINK1 abolished the protective effects of NGR1. In conclusion, these phenomena suggested that NGR1 prevented DR via PINK1-dependent enhancement of mitophagy.

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Tetrahydrocurcumin Ameliorates Diabetic Cardiomyopathy by Attenuating High Glucose-Induced Oxidative Stress and Fibrosis via Activating the SIRT1 Pathway

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/6746907 ◽

2019 ◽

Vol 2019 ◽

pp. 1-15 ◽

Cited By ~ 12

Author(s):

Kaifeng Li ◽

Mengen Zhai ◽

Liqing Jiang ◽

Fan Song ◽

Bin Zhang ◽

...

Keyword(s):

Oxidative Stress ◽

Signaling Pathway ◽

Diabetic Cardiomyopathy ◽

High Glucose ◽

Therapeutic Potential ◽

Ros Generation ◽

Protective Effects ◽

Collagen Iii

Hyperglycemia-induced oxidative stress and fibrosis play a crucial role in the development of diabetic cardiomyopathy (DCM). Tetrahydrocurcumin (THC), a major bioactive metabolite of natural antioxidant curcumin, is reported to exert even more effective antioxidative and superior antifibrotic properties as well as anti-inflammatory and antidiabetic abilities. This study was designed to investigate the potential protective effects of THC on experimental DCM and its underlying mechanisms, pointing to the role of high glucose-induced oxidative stress and interrelated fibrosis. In STZ-induced diabetic mice, oral administration of THC (120 mg/kg/d) for 12 weeks significantly improved the cardiac function and ameliorated myocardial fibrosis and cardiac hypertrophy, accompanied by reduced reactive oxygen species (ROS) generation. Mechanically, THC administration remarkably increased the expression of the SIRT1 signaling pathway both in vitro and in vivo, further evidenced by decreased downstream molecule Ac-SOD2 and enhanced deacetylated production SOD2, which finally strengthened antioxidative stress capacity proven by repaired activities of SOD and GSH-Px and reduced MDA production. Additionally, THC treatment accomplished its antifibrotic effect by depressing the ROS-induced TGFβ1/Smad3 signaling pathway followed by reduced expression of cardiac fibrotic markers α-SMA, collagen I, and collagen III. Collectively, these finds demonstrated the therapeutic potential of THC treatment to alleviate DCM mainly by attenuating hyperglycemia-induced oxidative stress and fibrosis via activating the SIRT1 pathway.

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A2AR Antagonists Upregulate Expression of GS and GLAST in Rat Hypoxia Model

BioMed Research International ◽

10.1155/2020/2054293 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Jun Yu ◽

Yan Yan ◽

Yiye Chen ◽

Yan Zheng ◽

Xiaoyan Yu ◽

...

Keyword(s):

Müller Cells ◽

Muller Cells ◽

Cell Viability Assay ◽

Hypoxic Conditions ◽

Viability Assay ◽

Drug Concentrations ◽

A Cell ◽

Short Time

Background. The aim of this study was to research the effects of glutamine synthetase (GS) and glutamate aspartate transporter (GLAST) in rat Müller cells and the effects of an adenosine A2AR antagonist (SCH 442416) on GS and GLAST in hypoxia both in vivo and in vitro. Methods. This study used RT-PCR and Western blotting to quantify the expressions of GS and GLAST under different hypoxic conditions as well as the expressions of GS and GLAST at different drug concentrations. A cell viability assay was used to assess drug toxicity. Results. mRNA and protein expression of GS and GLAST in hypoxia Group 24 h was significantly increased. mRNA and protein expressions of GS and GLAST both increased in Group 1 μM SCH 442416 compared with other groups. One micromolar SCH 442416 could upregulate GS and GLAST’s activity in hypoxia both in vivo and in vitro. Conclusions. Hypoxia activates GS and GLAST in rat retinal Müller cells in a short time in vitro. (2) A2AR antagonists upregulate the activity of GS and GLAST in hypoxia both in vivo and in vitro.

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Ganoderic Acid D Protects Human Amniotic Mesenchymal Stem Cells against Oxidative Stress-Induced Senescence through the PERK/NRF2 Signaling Pathway

Oxidative Medicine and Cellular Longevity ◽

10.1155/2020/8291413 ◽

2020 ◽

Vol 2020 ◽

pp. 1-18

Author(s):

Yan Xu ◽

Huan Yuan ◽

Yi Luo ◽

Yu-Jie Zhao ◽

Jian-Hui Xiao

Keyword(s):

Oxidative Stress ◽

Stem Cells ◽

Signaling Pathway ◽

Adult Stem Cells ◽

Telomerase Activity ◽

Related Factor ◽

Dependent Manner ◽

Ganoderic Acid ◽

Nrf2 Signaling Pathway

Aging is an important risk factor in the occurrence of many chronic diseases. Senescence and exhaustion of adult stem cells are considered as a hallmark of aging in organisms. In this study, a senescent human amniotic mesenchymal stem cell (hAMSC) model subjected to oxidative stress was established in vitro using hydrogen peroxide. We investigated the effects of ganoderic acid D (GA-D), a natural triterpenoid compound produced from Ganoderma lucidum, on hAMSC senescence. GA-D significantly inhibited β-galactosidase (a senescence-associated marker) formation, in a dose-dependent manner, with doses ranging from 0.1 μM to 10 μM, without inducing cytotoxic side-effects. Furthermore, GA-D markedly inhibited the generation of reactive oxygen species (ROS) and the expression of p21 and p16 proteins, relieved the cell cycle arrest, and enhanced telomerase activity in senescent hAMSCs. Furthermore, GA-D upregulated the expression of phosphorylated protein kinase R- (PKR-) like endoplasmic reticulum kinase (PERK), peroxidase III (PRDX3), and nuclear factor-erythroid 2-related factor (NRF2) and promoted intranuclear transfer of NRF2 in senescent cells. The PERK inhibitor GSK2656157 and/or the NRF2 inhibitor ML385 suppressed the PERK/NRF2 signaling, which was activated by GA-D. They induced a rebound for the generation of ROS and β-galactosidase-positive cells and attenuated the differentiation capacity. These findings suggest that GA-D retards hAMSC senescence through activation of the PERK/NRF2 signaling pathway and may be a promising candidate for the discovery of antiaging agents.

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Salvianolic Acid A Protects the Kidney against Oxidative Stress by Activating the Akt/GSK-3β/Nrf2 Signaling Pathway and Inhibiting the NF-κB Signaling Pathway in 5/6 Nephrectomized Rats

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/2853534 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16 ◽

Cited By ~ 7

Author(s):

Hong-feng Zhang ◽

Jia-hong Wang ◽

Yan-li Wang ◽

Cheng Gao ◽

Yan-ting Gu ◽

...

Keyword(s):

Oxidative Stress ◽

Western Blot ◽

Signaling Pathway ◽

Kidney Injury ◽

Dependent Manner ◽

Salvianolic Acid ◽

Nrf2 Signaling Pathway ◽

Antioxidative Effects ◽

Dose Dependent

Salvianolic acid A (SAA) is a bioactive polyphenol extracted from Salviae miltiorrhizae Bunge, which possesses a variety of pharmacological activities. In our previous study, we have demonstrated that SAA effectively attenuates kidney injury and inflammation in an established animal model of 5/6 nephrectomized (5/6Nx) rats. However, there has been limited research regarding the antioxidative effects of SAA on chronic kidney disease (CKD). Here, we examined the antioxidative effects and underlying mechanisms of SAA in 5/6Nx rats. The rats were injected with SAA (2.5, 5, and 10 mg·kg-1·d-1, ip) for 28 days. Biochemical, flow cytometry, and Western blot analyses showed that SAA significantly increased the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GPx), and catalase (CAT) and lowered the levels of malondialdehyde (MDA), reactive oxygen species (ROS), and NADPH oxidase 4 (NOX-4) in a dose-dependent manner in 5/6Nx rats and in H2O2-induced HK-2 cells in vitro. Moreover, SAA enhanced the activation of the protein kinase B/glycogen synthase kinase-3β/nuclear factor-erythroid-2-related factor 2 (Akt/GSK-3β/Nrf2) signaling pathway in a dose-dependent manner and subsequently increased the expression of heme oxygenase-1 (HO-1) in the kidney of 5/6Nx rats, which were consistent with those obtained in H2O2-induced HK-2 cells in vitro shown by Western blot analysis. Furthermore, SAA significantly increased the expression of intranuclear Nrf2 and HO-1 proteins compared to HK-2 cells stimulated by LPS on the one hand, which can be enhanced by QNZ to some extent; on the other hand, SAA significantly lowered the expression of p-NF-κB p65 and ICAM-1 proteins compared to HK-2 cells stimulated by H2O2, which can be abrogated by ML385 to some extent. In conclusion, our results demonstrated that SAA effectively protects the kidney against oxidative stress in 5/6Nx rats. One of the pivotal mechanisms for the protective effects of SAA on kidney injury was mainly related with its antioxidative roles by activating the Akt/GSK-3β/Nrf2 signaling pathway and inhibiting the NF-κB signaling pathway.

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