scholarly journals Nrf2 Suppresses Oxidative Stress and Inflammation in App Knock-In Alzheimer’s Disease Model Mice

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Akira Uruno ◽  
Daisuke Matsumaru ◽  
Rie Ryoke ◽  
Ritsumi Saito ◽  
Shiori Kadoguchi ◽  
...  

ABSTRACT Nrf2 (NF-E2-related-factor 2) is a stress-responsive transcription factor that protects cells against oxidative stresses. To clarify whether Nrf2 prevents Alzheimer’s disease (AD), AD model AppNL-G-F/NL-G-F knock-in (AppNLGF) mice were studied in combination with genetic Nrf2 induction model Keap1FA/FA mice. While AppNLGF mice displayed shorter latency to escape than wild-type mice in the passive-avoidance task, the impairment was improved in AppNLGF::Keap1FA/FA mice. Matrix-assisted laser desorption ionization–mass spectrometry imaging revealed that reduced glutathione levels were elevated by Nrf2 induction in AppNLGF::Keap1FA/FA mouse brains compared to AppNLGF mouse brains. Genetic Nrf2 induction in AppNLGF mice markedly suppressed the elevation of the oxidative stress marker 8-OHdG and Iba1-positive microglial cell number. We also determined the plasmalogen-phosphatidylethanolamine (PlsPE) level as an AD biomarker. PlsPE containing polyunsaturated fatty acids was decreased in the AppNLGF mouse brain, but Nrf2 induction attenuated this decline. To evaluate whether pharmacological induction of Nrf2 elicits beneficial effects for AD treatment, we tested the natural compound 6-MSITC [6-(methylsulfinyl)hexyl isothiocyanate]. Administration of 6-MSITC improved the impaired cognition of AppNLGF mice in the passive-avoidance task. These results demonstrate that the induction of Nrf2 ameliorates cognitive impairment in the AD model mouse by suppressing oxidative stress and neuroinflammation, suggesting that Nrf2 is an important therapeutic target of AD.

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Peng Ren ◽  
Jingwei Chen ◽  
Bingxuan Li ◽  
Mengzhou Zhang ◽  
Bei Yang ◽  
...  

Introduction. Alzheimer’s disease (AD), the most common neurodegenerative disorder, is characterized by the accumulation of amyloid-β (Aβ) peptide and hyperphosphorylated tau protein. Accumulating evidence has revealed that the slow progressive deterioration of AD is associated with oxidative stress and chronic inflammation in the brain. Nuclear factor erythroid 2- (NF-E2-) related factor 2 (Nrf2), which acts through the Nrf2/ARE pathway, is a key regulator of the antioxidant and anti-inflammatory response. Although recent data show a link between Nrf2 and AD-related cognitive decline, the mechanism is still unknown. Thus, we explored how Nrf2 protects brain cells against the oxidative stress and inflammation of AD in a mouse model of AD (APP/PS1 transgenic (AT) mice) with genetic removal of Nrf2. Methods. The spatial learning and memory abilities of 12-month-old transgenic mice were evaluated using a Morris water maze test. Hippocampal levels of Nrf2, Aβ, and p-tauS404 and of astrocytes and microglia were determined by immunostaining. Inflammatory cytokines were determined by ELISA and quantitative real-time polymerase chain reaction (qRT-PCR). Oxidative stress was measured by 8-hydroxydeoxyguanosine immunohistochemistry, and the antioxidant response was determined by qRT-PCR. Results. The spatial learning and memory abilities of AT mice were impaired after Nrf2 deletion. Aβ and p-tauS404 accumulation was increased in the hippocampus of AT/Nrf2-KO mice. Astroglial and microglial activation was exacerbated, followed by upregulation of the proinflammatory cytokines IL-1β, IL-6, and TNF-α. Conclusion. Our present results show that Nrf2 deficiency aggravates AD-like pathology in AT mice. This phenotype was associated with increased levels of oxidative and proinflammatory markers, which suggests that the Nrf2 pathway may be a promising therapeutic target for AD.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Luca Massaccesi ◽  
Emanuela Galliera ◽  
Daniela Galimberti ◽  
Chiara Fenoglio ◽  
Marina Arcaro ◽  
...  

2016 ◽  
Vol 28 (6) ◽  
pp. 315-320 ◽  
Author(s):  
Sadiye Gumusyayla ◽  
Gonul Vural ◽  
Hesna Bektas ◽  
Orhan Deniz ◽  
Salim Neselioglu ◽  
...  

ObjectiveThe aim of this study was to evaluate the dynamic thiol–disulphide homeostasis as an oxidative stress parameter, using a newly proposed method, in patients with Alzheimer’s disease.MethodsIn total, 97 participants were included in the study. Among them, 51 had been diagnosed with Alzheimer’s disease, and the remaining 46 were healthy individuals. Total thiol (–SH+–S–S–) levels and native thiol (–SH) levels in serum of each participant were measured. The amount of dynamic disulphide bonds (–S–S–) and (–S–S–) ×100/(–SH), (–S–S–) ×100/(–SH+–S–S–), and –SH×100/(–SH+–S–S–) ratios were calculated from these values. The obtained data were used to compare Alzheimer’s disease patients with healthy individuals.ResultsThe average total thiol and native thiol levels of patient with Alzheimer’s disease in the study were found to be significantly lower than those levels of healthy individuals. In addition, in the patient group, the –S–S–×100/–S–S+–SH ratio was found to be significantly higher, whereas the –SH×100/–S–S+–SH ratio was found to be significantly lower compared with healthy individuals. Total thiol and native thiol levels, dynamic disulphide bond amount, and –S–S–×100/–SH, –S–S–×100/–S–S+–SH, and –SH×100/–S–S+–SH ratios were not found to be correlated with mini mental state examination score or duration of disease.ConclusionRecent studies have shown that oxidative stress is the one of the molecular changes underlying the pathogenesis of Alzheimer’s disease. In this study, we have investigated the dynamic thiol–disulphide homeostasis in patients with Alzheimer’s disease, using a novel method.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Mamdooh H. Ghoneum ◽  
Nesrine S. El Sayed

Alzheimer’s disease (AD) is a debilitating and irreversible brain disease that affects an increasing number of aged individuals, mandating the development of protective nutraceuticals. Biobran/MGN-3, an arabinoxylan from rice bran, has potent antioxidant, antiaging, and immunomodulatory effects. The aim of the present study was to investigate the protective effect of Biobran against sporadic Alzheimer’s disease (SAD). SAD was induced in mice via intracerebroventricular injection of streptozotocin (STZ) (3 mg/kg). STZ-treated mice were administered with Biobran for 21 days. The effects of Biobran on memory and learning were measured via the Morris water maze, novel object recognition, and Y-maze tests. Biomarkers for apoptosis, oxidative stress, and amyloidogenesis were measured using ELISA and western blot analysis. Histopathological examination was performed to confirm neuronal damage and amyloid-beta deposition. Biobran reversed the spatial memory deficit in SAD-induced mice, and it increased the expression of glutathione, reduced malondialdehyde, decreased IL-6, decreased intercellular adhesion molecule-1 (ICAM-1), and significantly increased nuclear factor erythroid 2-related factor 2 (Nrf2) and antioxidant response element (ARE). Moreover, Biobran exerted a protective effect against amyloid-beta-induced apoptosis via the suppression of both cleaved caspase-3 and the proapoptotic protein Bax and via the upregulation of the antiapoptotic protein Bcl-2. Furthermore, it reduced the expression of forkhead box class O proteins. It could be concluded from this study that Biobran may be a useful nutritional antioxidant agent for protection against SAD through its activation of the gene expression of Nrf2/ARE, which in turn modulates the apoptotic and amyloidogenic pathways.


2020 ◽  
Author(s):  
Yan Wang ◽  
Meiling Lian ◽  
Jing Zhou ◽  
shengzhou wu

Abstract Background Oxidative stress critically underlies the neurodegenerative pathogenesis of Alzheimer's disease (AD). Depletion of Dicer1, an endoribonuclease central to microRNA maturation, also leads to neurodegeneration. We therefore hypothesized that altered Dicer1 expression may play a role in AD. Results Using immunoblotting and quantitative real-time PCR, we found that Dicer1 protein and mRNA levels were reduced in the hippocampi of animals of the AD mouse model APPswe/PSEN1dE9 compared with littermate controls. SiRNA-meditated Dicer1 knockdown induced oxidative stress, reduced mitochondrial intermembrane potential, and increased apoptosis in cultured neurons. Aβ42 exposure decreased Dicer1 and also down-regulated the oxidative stress–induced transcriptional regulator nuclear factor erythroid 2-related factor 2 (Nrf2). Conversely, Nrf2 overexpression increased Dicer1 mRNA and protein levels and reverted the Aβ42-induced Dicer1 reduction. To further investigate Dicer1 regulation, we cloned Dicer1 promoter variants harboring the Nrf2-binding site, the antioxidant response elements (ARE), into a luciferase reporter and found that simultaneous transfection of Nrf2-expressing plasmid increased luciferase expression from these promoter constructs. ChIP assays indicated that Nrf2 directly interacted with the ARE motifs in the Dicer1 promoter. Furthermore, Dicer1 overexpression in cultured neurons reverted Aβ42-induced neurite deficits. Of note, injection of Dicer1-expressing adenovirus into the hippocampus of the AD mice significantly improved spatial learning. Conclusions These findings indicate that Dicer1 expression is reduced in the AD brain and that chronic Aβ exposure decreases Dicer1 levels in neurons via Nrf2–ARE signaling. Our results uncover a significant role for Dicer1 in AD and highlight that Dicer1 expression responds to oxidative stress in the brain.


2022 ◽  
Vol 8 (1) ◽  
pp. 7-16
Author(s):  
Adeleh Jafari ◽  
◽  
Parvin Babaei ◽  
Kambiz Rohampour ◽  
Samira Rashtiani ◽  
...  

Background: Numerous pieces of evidence support that oxidative stress is a key factor in the pathogenesis of neurodegenerative diseases, like Alzheimer’s Disease (AD). Suppression of oxidative stress is an attractive strategy and flavonoids as potent natural antioxidants are extremely noticeable. Objectives: In this study, the effects of Kaempferol (KMP) were evaluated on passive avoidance memory, hippocampal Nrf-2, and beclin-1 expression in a rat model of Aβ1-42 –induced AD. Materials & Methods: Forty male Wistar rats weighing 200-250 g were divided into five groups (n=8); sham-operated, AD model, and KMP treatment (5, 7.5, 10 mg/kg, i.p. for three weeks). Animals received an intracerebroventricular injection of amyloid-beta (1-42) to establish an AD model. Passive avoidance memory of rats was evaluated using a shuttle box on day 21; Step-Through Latency (STL) and time spent in The Dark Compartment (TDC) were recorded. Then, hippocampus homogenates were used for biochemical and molecular analysis by real-time PCR, western blot, and ELISA. Results: It was found that KMP improved memory evidenced by increased STL (P≤0.05) and decreased TDC (p≤0.01). KMP also increased the levels of Total Antioxidant Capacity (TAC) in the hippocampus of rats (P≤0.05). In addition, KMP enhanced the expression of Nrf-2 mRNA (P≤0.001) and beclin-1 protein in the hippocampus tissues (P≤0.001). Conclusion: Overall, it is suggested that the memory-improving effect of KMP is mediated, at least in part, by enhancing Nrf-2 and TAC. KMP is also able to induce autophagy through the expression of beclin-1.


2021 ◽  
Author(s):  
Shunxi Zhang ◽  
Jia He Zhao ◽  
Zhihuai Bai ◽  
Fan Wu ◽  
Lina Luo ◽  
...  

Sulforaphane (SFN), a potent nuclear factor erythroid 2-related factor 2 (Nrf2) activator, presents a very potential role in improving the Alzheimer's disease (AD)-specific symptoms. However, the regulation mechanism of SFN...


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Chen Li ◽  
Ruili Wang ◽  
Youyou Zhang ◽  
Chunting Hu ◽  
Qiaoya Ma

Abstract Background Alzheimer’s disease (AD), the most common form of dementia, is caused by the degeneration of the central nervous system (CNS). A previous study reported that signal transducer and activator of transcription 3 (STAT3) is activated during AD development; nonetheless, the related mechanism remains unknown. Thus, this study used a cell model to explore whether and how the protein inhibitor of activated STAT3 (PIAS3) is involved in AD development. Methods Cerebrospinal fluid (CSF) specimens of 30 patients with AD and 10 normal participants were included in this study. SH-SY5Y cells were used to constructed AD model. Relevant indices were then detected and analyzed. Results The results showed that compared with the control group, PIAS3 expression was substantially decreased in patients with AD and amyloid beta (Aβ)-treated SH-SY5Y cells. PIAS3 overexpression was able to reverse the detrimental effects of Aβ treatment on cell survival and growth. Further, it could also ameliorate apoptosis and oxidative stress in Aβ-treated SH-SY5Y cells. Additionally, PIAS3 was shown to reduce the activated form of STAT3 and increase the activity of the downstream Nestin/nuclear factor erythroid 2-related factor/heme oxygenase-1 pathway. Conclusions STAT3 reactivation by colivelin treatment negated the influence of PIAS3 on the survival, growth, apoptosis, and oxidative stress of Aβ-treated SH-SY5Y cells.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Katja Kanninen ◽  
Anthony R. White ◽  
Jari Koistinaho ◽  
Tarja Malm

Specific regions of the Alzheimer's disease (AD) brain are burdened with extracellular protein deposits, the accumulation of which is concomitant with a complex cascade of overlapping events. Many of these pathological processes produce oxidative stress. Under normal conditions, oxidative stress leads to the activation of defensive gene expression that promotes cell survival. At the forefront of defence is the nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that regulates a broad spectrum of protective genes. Glycogen synthase kinase-3β (GSK-3β) regulates Nrf2, thus making this kinase a potential target for therapeutic intervention aiming to boost the protective activation of Nrf2. This paper aims to review the neuroprotective role of Nrf2 in AD, with special emphasis on the role of GSK-3β in the regulation of the Nrf2 pathway. We also examine the potential of inducing GSK-3β by small-molecule activators, dithiocarbamates, which potentially exert their beneficial therapeutic effects via the activation of the Nrf2 pathway.


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