scholarly journals Farrerol Directly Targets GSK-3β to Activate Nrf2-ARE Pathway and Protect EA.hy926 Cells against Oxidative Stress-Induced Injuries

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Chaoqun Yan ◽  
Xiaoyan Zhang ◽  
Junqiu Miao ◽  
Hongxia Yuan ◽  
Enli Liu ◽  
...  

Oxidative stress-mediated endothelial injury is considered to be involved in the pathogenesis of various cardiovascular diseases. Farrerol, a typical natural flavanone from the medicinal plant Rhododendron dauricum L., has been reported to show protective effects against oxidative stress-induced endothelial injuries in our previous study. However, its action molecular mechanisms and targets are still unclear. In the present study, we determined whether farrerol can interact with glycogen synthase kinase 3β- (GSK-3β-) nuclear factor erythroid 2-related factor 2- (Nrf2-) antioxidant response element (ARE) signaling, which is critical in defense against oxidative stress. Our results demonstrated that farrerol could specifically target Nrf2 negative regulator GSK-3β and inhibit its kinase activity. Mechanistic studies proved that farrerol could induce an inhibitory phosphorylation of GSK-3β at Ser9 without affecting the expression level of total GSK-3β protein and promote the nuclear translocation of Nrf2 as well as the mRNA and protein expression of its downstream target genes heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) in EA.hy926 cells. Further studies performed with GSK-3β siRNA and specific inhibitor lithium chloride (LiCl) confirmed that GSK-3β inhibition was involved in farrerol-mediated endothelial protection and Nrf2 signaling activation. Moreover, molecular docking and molecular dynamics studies revealed that farrerol could bind to the ATP pocket of GSK-3β, which is consistent with the ATP-competitive kinetic behavior. Collectively, our results firstly demonstrate that farrerol could attenuate endothelial oxidative stress by specifically targeting GSK-3β and further activating the Nrf2-ARE signaling pathway.

2021 ◽  
Vol 11 ◽  
Author(s):  
Jianjian Dong ◽  
Xiaoming Zhang ◽  
Shijing Wang ◽  
Chenchen Xu ◽  
Manli Gao ◽  
...  

Studies have indicated that oxidative stress plays a crucial role in the development of Parkinson’s disease (PD) and other neurodegenerative conditions. Research has also revealed that nuclear factor erythroid 2-related factor 2 (Nrf2) triggers the expression of antioxidant genes via a series of antioxidant response elements (AREs), thus preventing oxidative stress. Thymoquinone (TQ) is the bioactive component of Nigella sativa, a medicinal plant that exhibits antioxidant and neuroprotective effects. In the present study we examined whether TQ alleviates in vivo and in vitro neurodegeneration induced by 1-methyl-4-phenylpyridinium (MPP+) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) by acting as an activator of the Nrf2/ARE cascade. We showed that TQ significantly reduced MPP+-mediated cell death and apoptosis. Moreover, TQ significantly elevated the nuclear translocation of Nrf2 and significantly increased the subsequent expression of antioxidative genes such as Heme oxygenase 1 (HO-1), quinone oxidoreductase (NQO1) and Glutathione-S-Transferase (GST). The application of siRNA to silence Nrf2 led to an abolishment in the protective effects of TQ. We also found that the intraperitoneal injection of TQ into a rodent model of PD ameliorated oxidative stress and effectively mitigated nigrostriatal dopaminergic degeneration by activating the Nrf2-ARE pathway. However, these effects were inhibited by the injection of a lentivirus wrapped Nrf2 siRNA (siNrf2). Collectively, these findings suggest that TQ alleviates progressive dopaminergic neuropathology by activating the Nrf2/ARE signaling cascade and by attenuating oxidative stress, thus demonstrating that TQ is a potential novel drug candidate for the treatment of PD.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hui Pan ◽  
Wenjing Feng ◽  
Ming Chen ◽  
Hong Luan ◽  
Yi Hu ◽  
...  

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.


2017 ◽  
Vol 232 (1) ◽  
pp. 71-83 ◽  
Author(s):  
Wenpeng Dong ◽  
Ye Jia ◽  
Xiuxia Liu ◽  
Huan Zhang ◽  
Tie Li ◽  
...  

Oxidative stress contributes to the pathogenesis of diabetic nephropathy (DN). Nuclear factor erythroid 2-related factor 2 (NRF2) plays a key role in cellular defense against oxidative stress. NRF2 activators have shown promising preventive effects on DN. Sodium butyrate (NaB) is a known activator of NRF2. However, it is unknown whether NRF2 is required for NaB protection against DN. Therefore, streptozotocin-induced diabetic C57BL/6 Nrf2 knockout and their wild-type mice were treated in the presence or absence of NaB for 20 weeks. Diabetic mice, but not NaB-treated diabetic mice, developed significant renal oxidative damage, inflammation, apoptosis, fibrosis, pathological changes and albuminuria. NaB inhibited histone deacetylase (HDAC) activity and elevated the expression of Nrf2 and its downstream targets heme oxygenase 1 and NAD(P)H dehydrogenase quinone 1. Notably, deletion of the Nrf2 gene completely abolished NaB activation of NRF2 signaling and protection against diabetes-induced renal injury. Interestingly, the expression of Kelch-like ECH-associated protein 1, the negative regulator of NRF2, was not altered by NaB under both diabetic and non-diabetic conditions. Moreover, NRF2 nuclear translocation was not promoted by NaB. Therefore, the present study indicates, for the first time, that NRF2 plays a key role in NaB protection against DN. Other findings suggest that NaB may activate Nrf2 at the transcriptional level, possibly by the inhibition of HDAC activity.


Nutrients ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 926 ◽  
Author(s):  
Shan Huang ◽  
Ning Meng ◽  
Zhiming Liu ◽  
Li Guo ◽  
Linsha Dong ◽  
...  

Oxidative stress-mediated neuron damage is considered an important contributor to the pathogenesis and development of neurodegenerative diseases. Taraxacum officinale has been reported to possess antioxidant activities. However, whether it can protect neurons against oxidative damage and the underlying molecular mechanisms have not been fully determined. In the present study, we examined the neuroprotective effects of ethanol extracts of this plant (ETOW) on glutamate-induced oxidative stress in HT22 cells. Both cell viability and reactive oxygen species (ROS) assays showed that ETOW effectively attenuated glutamate-induced cytotoxicity and ROS generation. Furthermore, our results revealed that ETOW increased the expression of heme oxygenase-1 (HO-1) and promoted the nuclear translocation of nuclear factor erythroid 2-related factor-2 (Nrf2). The inhibitory effects of ETOW on glutamate-stimulated cell toxicity and ROS production were partially reversed by tin protoporphyrin (SnPP), an HO activity inhibitor. Taken together, these results demonstrate that ETOW can protect HT22 cells against glutamate-induced oxidative damage by inducing the Nrf2/HO-1 pathways. Our study supports the idea that Taraxacum officinale Wigg. is a promising agent for preventing neurodegenerative diseases.


2020 ◽  
Vol 33 (7) ◽  
pp. 610-619 ◽  
Author(s):  
Peijian Wang ◽  
Yi Yang ◽  
Dan Wang ◽  
Qiyuan Yang ◽  
Jindong Wan ◽  
...  

Abstract BACKGROUND Oxidative stress is known to be associated with the development of diabetes. Cinnamaldehyde (CA) is a spice compound in cinnamon that enhances the antioxidant defense against reactive oxygen species (ROS) by activating nuclear factor erythroid-related factor 2 (Nrf2), which has been shown to have a cardioprotection effect. However, the relationship between CA and Nrf2 in diabetic vascular complications remains unclear. METHODS Leptin receptor-deficient (db/db) mice were fed normal chow or diet containing 0.02% CA for 12 weeks. The vascular tone, blood pressure, superoxide level, nitric oxide (NO) production, renal morphology, and function were measured in each group. RESULTS CA remarkably inhibited ROS generation, preserved NO production, increased phosphorylated endothelial nitric oxide synthase (p-eNOS), attenuated the upregulation of nitrotyrosine, P22 and P47 in aortas of db/db mice, and apparently ameliorated the elevation of type IV collagen, TGF-β1, P22, and P47 in kidney of db/db mice. Feeding with CA improved endothelium-dependent relaxation of aortas and mesenteric arteries, and alleviated the remodeling of mesenteric arteries in db/db mice. Additionally, dietary CA ameliorated glomerular fibrosis and renal dysfunction in diabetic mice. Nrf2 and its targeted genes heme oxygenase-1 (HO-1) and quinone oxidoreductase-1 (NQO-1) were slightly increased in db/db mice and further upregulated by CA. However, these protective effects of CA were reversed in Nrf2 downregulation mice. CONCLUSIONS A prolonged diet of CA protects against diabetic vascular dysfunction by inhibiting oxidative stress through activating of Nrf2 signaling pathway in db/db mice.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Si Huang ◽  
Haiyan Yuan ◽  
Wenqun Li ◽  
Xinyi Liu ◽  
Xiaojie Zhang ◽  
...  

Polygonatum sibiricum, a well-known life-prolonging tonic in Chinese medicine, has been widely used for nourishing nerves in the orient, but the underlying molecular mechanisms remain unclear. In this study, we found that P. sibiricum polysaccharides (PSP) ameliorated 1-methyl-4-phenyl-1,2.3,6-tetrahydropyridine- (MPTP-) induced locomotor activity deficiency and dopaminergic neuronal loss in an in vivo Parkinson’s disease (PD) mouse model. Additionally, PSP pretreatment inhibited N-methyl-4-phenylpyridine (MPP+) induced the production of reactive oxygen species, increasing the ratio of reduced glutathione/oxidized glutathione. In vitro experiments showed that PSP promoted the proliferation of N2a cells in a dose-dependent manner, while exhibiting effects against oxidative stress and neuronal apoptosis elicited by MPP+. These effects were found to be associated with the activation of Akt/mTOR-mediated p70S6K and 4E-BP1 signaling pathways, as well as nuclear factor erythroid 2-related factor 2- (Nrf2-) mediated NAD(P)H quinone oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (Gclc), and glutamate-cysteine ligase modulatory subunit (Gclm), resulting in antiapoptotic and antioxidative effects. Meanwhile, PSP exhibited no chronic toxicity in C57BJ/6 mice. Together, our results suggest that PSP can serve as a promising therapeutic candidate with neuroprotective properties in preventing PD.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jiayi Chen ◽  
Fangting He ◽  
Sijing Liu ◽  
Tao Zhou ◽  
Saira Baloch ◽  
...  

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.


2014 ◽  
Vol 34 (2) ◽  
pp. 145-152 ◽  
Author(s):  
B Shen ◽  
W Wang ◽  
L Ding ◽  
Y Sao ◽  
Y Huang ◽  
...  

Aim: This study aimed to determine whether nuclear factor erythroid 2-related factor 2 antagonized the oxidative stress induced by di- N-butylphthalate (DBP) in testicular Leydig cells. Methods: Mouse TM3 testicular Leydig cells were treated with Nrf2 knockdown (KD) or overexpression in the presence and absence of DBP. Oxidative profiles were examined. Nrf2 target antioxidant genes were studied, and the effects of Nrf2 inducer sulphoraphane (SFN) were tested. Results: DBP induced intracellular oxidative stress to a similar extent with Nrf2 KD. Expression and protein levels of Nrf2 were increased together with its target genes, namely heme oxygenase 1, nicotinamide adenine dinucleotide phosphate quinone oxidoreductase 1 and peroxiredoxin 6, following DBP stimulation. Use of SFN not only restored the intracellular oxidative toxicity but also cell proliferation and testosterone secretion in response to DBP. Conclusion: Increased Nrf2 activity, for example, by SFN can effectively antagonize the oxidative stress in testicular Leydig cells caused by DBP.


2019 ◽  
Vol 101 (5) ◽  
pp. 1018-1030 ◽  
Author(s):  
Narmada Lavu ◽  
Lauren Richardson ◽  
Enkhtuya Radnaa ◽  
Talar Kechichian ◽  
Rheanna Urrabaz-Garza ◽  
...  

Abstract Objective Oxidative stress (OS)-induced stress signaler p38 mitogen-activated protein kinase (p38MAPK) activation and fetal membrane senescence are associated with parturition. This study determined changes in glycogen synthase kinase 3 beta (GSK3β) and its regulation by p38MAPK in effecting senescence to further delineate the molecular mechanism involved in senescence. Methods Primary human amnion epithelial cells and amnion mesenchymal cells were treated with cigarette smoke extract (CSE, OS inducer). Expression of total and phosphorylated GSK3β and p38MAPK, and that of GSK3β’s downstream targets: beta-catenin (β-Cat) and nuclear factor erythroid 2-related factor 2 (Nrf2) (western blot analysis), cell cycle regulation and senescence (flow cytometry) were determined. The specificity of GSK3β and p38MAPK’s mechanistic role was tested by co-treating cells with their respective inhibitors, CHIR99021 and SB203580. Exosomal secretion of β-Cat from OS-induced cells was confirmed by immunofluorescence confocal microscopy and western blot. Results OS induced by CSE resulted in phosphorylation of GSK3β (inactivation) and p38MAPK (activation) that was associated with cell cycle arrest and senescence. Inhibitors to GSK3β and p38MAPK verified their roles. Glycogen synthase kinase 3 beta inactivation was associated with nuclear translocation of antioxidant Nrf2 and exosomal secretion of β-Cat. Conclusions OS-induced P-p38MAPK activation is associated with functional downregulation of GSK3β and arrest of cell cycle progression and senescence of amnion cells. Lack of nuclear translocation of β-Cat and its excretion via exosomes further supports the postulation that GSK3β down-regulation by p38MAPK may stop cell proliferation preceding cell senescence. A better understanding of molecular mechanisms of senescence will help develop therapeutic strategies to prevent preterm birth.


Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 116 ◽  
Author(s):  
Yuelian Li ◽  
Lu Liu ◽  
Peipei Sun ◽  
Yifeng Zhang ◽  
Tao Wu ◽  
...  

In recent years, microalgae have drawn increasing attention as a valuable source of functional food ingredients. Intriguingly, Nitzschia laevis is rich in fucoxanthinol that is seldom found in natural sources. Fucoxanthinol, a marine xanthophyll carotenoid, possesses various beneficial bioactivities. Nevertheless, it’s not clear whether fucoxanthinol could exert anti-neuroinflammatory function. In light of these premises, the aim of the present study was to investigate the anti-inflammatory role of fucoxanthinol purified from Nitzschia laevis in Lipopolysaccharide (LPS)-stimulated microglia. The results showed that pre-treatment of fucoxanthinol remarkably attenuated the expression of LPS-induced nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the production of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE-2), nitric oxide (NO) and reactive oxygen species (ROS) induction. Modulation mechanism studies revealed that fucoxanthinol hampered nuclear factor-kappa B (NF-κB), Akt, and mitogen-activated protein kinase (MAPK) pathways. Meanwhile, fucoxanthinol led to the enhancement of nuclear translocation of NF-E2-related factor 2 (Nrf2), and the upregulation of heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO-1). Taken together, the results indicated that fucoxanthinol obtained from Nitzschia laevis had great potential as a neuroprotective agent in neuroinflammation and neurodegenerative disorders.


Sign in / Sign up

Export Citation Format

Share Document