Nrf2--a therapeutic target for the treatment of neurodegenerative diseases

Fam163a knockdown and mitochondrial stress in the arcuate nucleus of hypothalamus reduce AgRP neuron activity and differentially regulate mitochondrial dynamics in mice

AIM

Mitochondria play key roles in neuronal activity, particularly in modulating agouti-related protein (AgRP) and proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC), which regulates food intake. FAM163A, a newly identified protein, is suggested to be part of the mitochondrial proteome, though its functions remain largely unknown. This study aimed to investigate the effects of Fam163a knockdown and mitochondrial dysfunction on food intake, AgRP neuron activity, and mitochondrial function in the hypothalamus.

METHODS

Male C57BL/6 and AgRP-Cre mice received intracranial injections of either Fam163a shRNA, rotenone, or appropriate controls. Behavioral assessments included food intake, locomotor activity, and anxiety-like behaviors. qRT-PCR was used to quantify the expression of the genes related to food intake, mitochondrial biogenesis, dynamics, and oxidative stress. Blood glucose, serum insulin, and leptin levels were measured. Electrophysiological patch-clamp recordings were used to assess the AgRP neuronal activity.

RESULTS

Fam163a knockdown in the ARC increased the cumulative food intake in short term (first 7 days) without altering the 25-day food intake and significantly increased the Pomc mRNA expression. Fam163a silencing significantly reduced leptin levels. Both Fam163a knockdown and rotenone significantly reduced the firing frequency of AgRP neurons. Neither Fam163a silencing nor rotenone altered locomotor or anxiety-like behaviors. Fam163a knockdown and rotenone differentially altered the expression of mitochondrial biogenesis-, mitophagy-, fusion-, and oxidative stress-related genes.

CONCLUSION

Hypothalamic FAM163A may play a role in modulating AgRP neuronal activity through regulating mitochondrial biogenesis, dynamics, and redox state. These findings provide insights into the role of FAM163A and mitochondrial stress in the central regulation of metabolism.

Laminin-dystroglycan mediated ferroptosis in hemorrhagic shock and reperfusion induced-cognitive impairment through AMPK/Nrf2

Hemorrhagic shock and reperfusion (HSR) is the main cause of death following trauma. Cognitive impairment may persist after successful resuscitation from hemorrhagic shock, but the mechanisms remain elusive. This study demonstrated the presence of ferroptosis in an in vitro model of oxygen-glucose deprivation and reoxygenation (OGD/R) in HT22 neurons, and also in a murine model of HSR using 3-month-old C57BL/6 mice. The ferroptosis induced by OGD/R was characterized by transmission electron microscopy, the localization of FTH1 and TFR1 in HT22 cells. However, neuronal ferroptosis was prevented by suppressing AMPK through siRNA transfection or AMPK inhibitor pretreatment (compound C) in vitro. There was a consistent increase in Nrf2 with ROS accumulation, iron deposition, and lipid peroxidation in the hippocampal neurons and tissues. Nrf2 knockdown or overexpression significantly modulated OGD/R induced-ferroptosis. Activating ferroptosis by erastin (a ferroptosis inducer) or inhibiting it by ferrostatin-1 (a ferroptosis inhibitor) respectively enhanced or mitigated cognitive deficits as well as the ferroptosis-related changes induced by HSR. In addition to the improved cognition, single-nucleus transcriptome analysis of ipsilateral hippocampi from Nrf2-/- mice demonstrated the broad decrease of ferroptosis in neuronal cell clusters. LAMA2 and DAG1 were dominantly elevated and co-localized in the hippocampal CA3 region of Nrf2-/- mice by fluorescence in situ hybridization. The activation of astrocytes was significantly attenuated after Nrf2 knockout, associated with the increases of laminin-dystroglycan during astrocyte-neuron crosstalk. Thus, data from this study proposes a novel explanation, namely laminin-dystroglycan interactions during astrocytes-neurons crosstalk stimulating AMPK and Nrf2 induced neuronal ferroptosis, for the development of cognitive impairment after HSR.

Emerging Ferroptosis Involvement in Amyotrophic Lateral Sclerosis Pathogenesis: Neuroprotective Activity of Polyphenols

Neurodegenerative diseases are a group of diseases that share common features, such as the generation of misfolded protein deposits and increased oxidative stress. Among them, amyotrophic lateral sclerosis (ALS), whose pathogenesis is still not entirely clear, is a complex neurodegenerative disease linked both to gene mutations affecting different proteins, such as superoxide dismutase 1, Tar DNA binding protein 43, Chromosome 9 open frame 72, and Fused in Sarcoma, and to altered iron homeostasis, mitochondrial dysfunction, oxidative stress, and impaired glutamate metabolism. The purpose of this review is to highlight the molecular targets common to ALS and ferroptosis. Indeed, many pathways implicated in the disease are hallmarks of ferroptosis, a recently discovered type of iron-dependent programmed cell death characterized by increased reactive oxygen species (ROS) and lipid peroxidation. Iron accumulation results in mitochondrial dysfunction and increased levels of ROS, lipid peroxidation, and ferroptosis triggers; in addition, the inhibition of the Xc- system results in reduced cystine levels and glutamate accumulation, leading to excitotoxicity and the inhibition of GPx4 synthesis. These results highlight the potential involvement of ferroptosis in ALS, providing new molecular and biochemical targets that could be exploited in the treatment of the disease using polyphenols.

Oxidative Stress Indicated by Nuclear Transcription Factor Nrf2 and Glutathione Status in the Blood of Young Children with Autism Spectrum Disorder: Pilot Study

This pilot study investigated the relationship between nuclear transcription factor Nrf2 and glutathione homeostasis in children with autism spectrum disorder (ASD), addressing the role of oxidative stress in ASD pathophysiology. Oxidative stress, characterized by an imbalance between reactive oxygen species and antioxidant defenses, has been implicated in ASD and may contribute to neuroinflammation and mitochondrial dysfunction. Nrf2, a key regulator of the antioxidant response, influences glutathione synthesis and recycling, making it critical for cellular redox balance. This study included 23 children with ASD and 21 neurotypical healthy controls, and measured levels of Nrf2, Keap1 (Kelch-like ECH-associated protein 1), reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione reductase (GR), and peroxidase (GPx3) in blood samples. Our study reveals altered antioxidant defense in children with autism spectrum disorder, as evidenced by reduced levels of Nrf2, Keap1, GSH, and GR, along with elevated GSSG and a lower GSH/GSSG ratio. These findings indicate an increased oxidative stress burden in this population. Additionally, the observed positive correlation between Nrf2, GSH, and GR levels suggests an important role for Nrf2 in maintaining glutathione homeostasis. Our results underscore the potential involvement of oxidative stress in ASD and emphasize the need for further research into targeted therapeutic approaches to address this imbalance.

diAcCA, a Pro-Drug for Carnosic Acid That Activates the Nrf2 Transcriptional Pathway, Shows Efficacy in the 5xFAD Transgenic Mouse Model of Alzheimer's Disease

The antioxidant/anti-inflammatory compound carnosic acid (CA) is a phenolic diterpene found in the herbs rosemary and sage. Upon activation, CA manifests electrophilic properties to stimulate the Nrf2 transcriptional pathway via reaction with Keap1. However, purified CA is readily oxidized and thus highly unstable. To develop CA as an Alzheimer's disease (AD) therapeutic, we synthesized pro-drug derivatives, among which the di-acetylated form (diAcCA) showed excellent drug-like properties. diAcCA converted to CA in the stomach prior to absorption into the bloodstream, and exhibited improved stability and bioavailability as well as comparable pharmacokinetics (PK) and efficacy to CA. To test the efficacy of diAcCA in AD transgenic mice, 5xFAD mice (or littermate controls) received the drug for 3 months, followed by behavioral and immunohistochemical studies. Notably, in addition to amyloid plaques and tau tangles, a hallmark of human AD is synapse loss, a major correlate to cognitive decline. The 5xFAD animals receiving diAcCA displayed synaptic rescue on immunohistochemical analysis accompanied by improved learning and memory in the water maze test. Treatment with diAcCA reduced astrocytic and microglial inflammation, amyloid plaque formation, and phospho-tau neuritic aggregates. In toxicity studies, diAcCA was as safe or safer than CA, which is listed by the FDA as "generally regarded as safe", indicating diAcCA is suitable for human clinical trials in AD.

Unraveling the role of Nrf2 in dopaminergic neurons: a review of oxidative stress and mitochondrial dysfunction in Parkinson's disease

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an essential transcriptional factor, involved in the regulation of countenance of various anti-oxidant enzymes and cytoprotective genes that respond to mitochondrial dysfunctions, oxidative stress, and neuroinflammation, thus potentially contributing to several neurodegenerative diseases (NDDs), including Parkison's disease (PD). PD is the second most prevalent progressive NDD, characterized by gradual neuronal death in substantia nigra pars compacta (SNpc), depletion of dopamine level, and a wide range of motor symptoms, including bradykinesia, tremor, tingling, and muscle fatigue. The etiopathology of PD is caused by multifactorial intertwined with the onset and progression of the disease. In this context, Nrf2 exhibits neuroprotective action by preserving dopaminergic neurons in the striatum and retarding the disease progression; thus, Nrf2 activation plays a crucial role in PD. Additionally, Nrf2 binds with the antioxidant response element, which is located in the promoter region of most of the genes that are responsible for coding antioxidant enzymes. Moreover, protein kinase C (PKC) mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinase (PI3K) are also involved in the regulation of Keap1 pathway-mediated Nrf2 activation. As Nrf2 revealed its defensive and protective role in the central nervous system (CNS), it is gaining enough interest in treating PD. The treatments that are currently available are intended to alleviate the symptoms of PD; however, they are unable to halt the progression and severity of the disease. Therefore, in this review we delve deeper into various molecular mechanisms associated with oxidative stress, mitochondrial dysfunction, and neuroinflammation in PD. Additionally, we elaborated on the substantial role that NRF2 plays in mitigating these adverse effects and its potential as a therapeutic target.

Rlip76 in ageing and Alzheimer's disease: Focus on oxidative stress and mitochondrial mechanisms

RLIP76 (Rlip), a stress-responsive protein, plays a multifaceted role in cellular function. This protein acts primarily as a glutathione-electrophile conjugate (GS-E) transporter, crucial for detoxifying hazardous compounds and converting them into mercapturic acids. RLIP76 also modulates cytoskeletal motility and membrane plasticity through its role in the Ral-signaling pathway, interacting with RalA and RalB, key small GTPases involved in growth and metastasis. Beyond its ATP-dependent transport functions in various tissues, RLIP76 also demonstrates GTPase Activating Protein (GAP) activity towards Rac1 and Cdc42, with a preference for Ral-GTP over Ral-GDP. Its functions span critical physiological processes including membrane dynamics, oxidative stress response, and mitochondrial dynamics. The protein's widespread expression and evolutionary conservation underscore its significance. Our lab discovered that Rlip interacts with Alzheimer's disease (AD) proteins, amyloid beta and phosphorylated and induce oxidative stress, mitochondrial dysfnction and synaptic damage in AD. Our in vitro studies revealed that overexpression of Rlip reduces mitochondrial abnormalities. Further, our in vivo studies (Rlip+/- mice) revealed that a partial reduction of Rlip in mice (Rlip+/-), leads to mitochondrial abnormalities, elevated oxidative stress, and cognitive deficits resembling late-onset AD, emphasizing the protein's crucial role in neuronal health and disease. Finally, we discuss the experimental cross-breedings of overexpression of mice Rlip TG/TG or Rlip + /- mice with Alzheimer's disease models - earlyonset 5XFAD, late-onset APPKI and Tau transgenic mice, providing new insights into RLIP76's role in AD progression and development. This review summarizes RLIP76's structure, function, and cellular pathways, highlighting its implications in AD and its potential as a therapeutic target.

Nrf2-Independent Anti-Inflammatory Effects of Dimethyl Fumarate: Challenges and Prospects in Developing Electrophilic Nrf2 Activators for Neurodegenerative Diseases

The NF-E2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway is a potential therapeutic target for central nervous system diseases. This review emphasizes the role of oxidative stress and neuroinflammation in neurodegenerative diseases, highlighting the therapeutic potential of Nrf2 activators such as dimethyl fumarate (DMF). DMF, initially administered for treating psoriasis, has demonstrated efficacy in multiple sclerosis and is metabolized to monomethyl fumarate, which may exert significant therapeutic effects. DMF activates the Nrf2-ARE pathway, and recent studies have indicated that its anti-inflammatory effects occur through Nrf2-independent mechanisms. Electrophilic Nrf2 activators, such as DMF, covalently bind to cysteine residues in proteins and modulate their function. We discuss the implications of cysteine residue modifications by DMF, which may cause both therapeutic benefits and potential off-target effects. Furthermore, we propose a chemical proteomics-based drug discovery approach to achieve desired therapeutic effects by selectively covalently modifying cysteines in target proteins. These findings advocate for a broader understanding of the Nrf2-independent mechanisms of electrophilic Nrf2 activators, thereby improving drug discovery strategies that target neurodegenerative diseases while minimizing toxicity.

Pedunculoside alleviates cognitive deficits and neuronal cell apoptosis by activating the AMPK signaling cascade

BACKGROUND

Mitochondrial dysfunction emerges as an early pathological hallmark of Alzheimer's disease (AD). The reduction in mitochondrial membrane potential and the elevation of reactive oxygen species (ROS) production are pivotal in the initiation of neuronal cell apoptosis. Pedunculoside(Ped), a novel triterpene saponin derived from the dried barks of Ilex rotunda Thunb, exhibits a potent anti-inflammatory effect. In the course of drug screening, we discovered that Ped offers significant protection against apoptosis induced by Aβ1-42. Nevertheless, the role and mechanism of Ped in AD are yet to be elucidated.

METHODS

Oxidative stress was evaluated by measuring mitochondrial membrane potential and intracellular ROS production. The expression of proteins associated with apoptosis was determined using western blot analysis and flow cytometry. In vivo, the pathological characteristics of AD were investigated through Western blot and tissue immunofluorescence techniques. Cognitive function was assessed using the Morris Water Maze and Novel Object Recognition tests.

RESULTS

We demonstrated that Ped decreased apoptosis in PC12 cells, reduced the generation of intracellular ROS, and restored mitochondrial membrane potential. Mechanistically, we found that the protective effect of Ped against Aβ-induced neurotoxicity was associated with activation of the AMPK/GSK-3β/Nrf2 signaling pathway. In vivo, Ped alleviated memory deficits and inhibited neuronal apoptosis, inflammation, and oxidative stress in the hippocampus of 3 × Tg AD mice, along with the activation of the AMPK signaling pathway.

CONCLUSION

The findings indicate that Ped exerts its neuroprotective effects against oxidative stress and apoptosis through the AMPK signaling cascade. The results demonstrate that Ped is a potential candidate for the treatment of AD.

Nrf2 pathways in neuroprotection: Alleviating mitochondrial dysfunction and cognitive impairment in aging

Mitochondrial dysfunction and cognitive impairment are widespread phenomena among the elderly, being crucial factors that contribute to neurodegenerative diseases. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important regulator of cellular defense systems, including that against oxidative stress. As such, increased Nrf2 activity may serve as a strategy to avert mitochondrial dysfunction and cognitive decline. Scientific data on Nrf2-mediated neuroprotection was collected from PubMed, Google Scholar, and Science Direct, specifically addressing mitochondrial dysfunction and cognitive impairment in older people. Search terms included "Nrf2", "mitochondrial dysfunction," "cognitive impairment," and "neuroprotection." Studies focusing on in vitro and in vivo models and clinical investigations were included to review Nrf2's therapeutic potential comprehensively. The relative studies have demonstrated that increased Nrf2 activity could improve mitochondrial performance, decrease oxidative pressure, and mitigate cognitive impairment. To a large extent, this is achieved through the modulation of critical cellular signalling pathways such as the Keap1/Nrf2 pathway, mitochondrial biogenesis, and neuroinflammatory responses. The present review summarizes the recent progress in comprehending the molecular mechanisms regarding the neuroprotective benefits mediated by Nrf2 through its substantial role against mitochondrial dysfunction and cognitive impairment. This review also emphasizes Nrf2-target pathways and their contribution to cognitive function improvement and rescue from mitochondria-related abnormalities as treatment strategies for neurodegenerative diseases that often affect elderly individuals.

Structure-Guided Conformational Restriction Leading to High-Affinity, Selective, and Cell-Active Tetrahydroisoquinoline-Based Noncovalent Keap1-Nrf2 Inhibitors

Inhibition of the protein-protein interaction between Kelch-like ECH-associated protein 1 (Keap1) and nuclear factor erythroid 2-related factor 2 (Nrf2) has been recognized as an attractive approach for treating oxidative stress-related diseases. Here, we present a new series of noncovalent Keap1-Nrf2 inhibitors developed by a conformational restriction strategy of our fluorenone-based compounds previously identified by fragment-based drug discovery. The design was guided by X-ray cocrystal structures, and the subsequent optimization process aimed at improving affinity, cellular activity, and metabolic stability. From the noncyclic compound 7 (Ki = 2.9 μM), a new series of tetrahydroisoquinoline-based Keap1 inhibitors with up to 223-fold improvement in binding affinity (57, Ki = 13 nM), better metabolic stability, and enhanced cellular activity was obtained. In addition, the compounds showed selectivity for the Keap1 Kelch domain across a panel of 15 homologous proteins. We thereby demonstrate the utility of cyclic rigidification in the design of potent and more drug-like Keap1-Nrf2 inhibitors.

The Role of Reactive Oxygen Species in Alzheimer's Disease: From Mechanism to Biomaterials Therapy

Alzheimer's disease (AD) is a chronic, insidious, and progressive neurodegenerative disease that remains a clinical challenge for society. The fully approved drug lecanemab exhibits the prospect of therapy against the pathological processes, while debatable adverse events conflict with the drug concentration required for the anticipated therapeutic effects. Reactive oxygen species (ROS) are involved in the pathological progression of AD, as has been demonstrated in much research regarding oxidative stress (OS). The contradiction between anticipated dosage and adverse event may be resolved through targeted transport by biomaterials and get therapeutic effects through pathological progression via regulation of ROS. Besides, biomaterials fix delivery issues by promoting the penetration of drugs across the blood-brain barrier (BBB), protecting the drug from peripheral degradation, and elevating bioavailability. The goal is to comprehensively understand the mechanisms of ROS in the progression of AD disease and the potential of ROS-related biomaterials in the treatment of AD. This review focuses on OS and its connection with AD and novel biomaterials in recent years against AD via OS to inspire novel biomaterial development. Revisiting these biomaterials and mechanisms associated with OS in AD via thorough investigations presents a considerable potential and bright future for improving effective interventions for AD.

Interaction of Cooking-Generated Aerosols on the Human Nervous System and the Impact of Caloric Restriction Post-Exposure

Background: The inhalation of cooking-generated aerosols could lead to translocation to the brain and impact its function; therefore, the effects of cooking-generated aerosols on healthy adults were investigated using an electroencephalograph (EEG) during the 2 h period post-exposure. Methods: To explore any changes from the impact of exposure to cooking-generated aerosols on the human brain due to the absence of food intake during exposure, we divided the study participants into three groups: (A) no food intake for 2 h (2 h-zero calorie intake), (B) non-zero calorie intake, and (C) control group (simulated cooking). Results: The ultrafine particle concentrations increased from 9.0 × 103 particles/cm3 at the background level to approximately 8.74 × 104 particles/cm3 during cooking. EEGs were recorded before cooking (step 1), 60 min after cooking (step 2), 90 min after cooking (step 3), and 120 min after cooking (step 4). Comparing the non-zero calorie group with the control group, it was concluded that exposure to cooking-generated aerosols resulted in a 12.82% increase in the alpha band two hours post-exposure, compared to pre-exposure. The results revealed that zero calorie intake after exposure mitigated the impacts of cooking-generated aerosols for the alpha, beta3, theta, and delta bands, while it exacerbated effects on the whole brain for the beta1 and beta2 bands. Conclusions: While these are short-term studies, long-term exposure to cooking-generated ultrafine particles can be established through successive short-term exposures. These results underscore the need for further research into the health impacts of cooking-generated aerosols and the importance of implementing strategies to mitigate exposure.

Discovery and Optimization of a Series of Vinyl Sulfoximine-Based Analogues as Potent Nrf2 Activators for the Treatment of Multiple Sclerosis

Multiple sclerosis (MS) is an immune-mediated neurodegenerative disease of the central nervous system (CNS), which leads to demyelination, axonal loss, and neurodegeneration. Increased oxidative stress and neurodegeneration have been implicated in all stages of MS, making neuroprotective therapeutics a promising strategy for its treatment. We previously have reported vinyl sulfones with antioxidative and anti-inflammatory properties that activate nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that induces the expression of cytoprotective genes against oxidative stress. In this study, we synthesized vinyl sulfoximine derivatives by modifying the core structure and determined therapeutic potential as Nrf2 activators. Among them, 10v effectively activated Nrf2 (EC50 = 83.5 nM) and exhibited favorable drug-like properties. 10v successfully induced expression of Nrf2-dependent antioxidant enzymes and suppressed lipopolysaccharide (LPS)-induced inflammatory responses in BV-2 microglial cells. We also confirmed that 10v effectively reversed disease progression and attenuated demyelination in an experimental autoimmune encephalitis (EAE) mouse model of MS.

Anti-oxidative stress and cognitive improvement of a semi-synthetic isoorientin-based GSK-3β inhibitor in rat pheochromocytoma cell PC12 and scopolamine-induced AD model mice via AKT/GSK-3β/Nrf2 pathway

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive cognitive deficits. Although the pathogenesis of AD is unclear, oxidative stress has been implicated to play a dominant role in its development. The flavonoid isoorientin (ISO) and its synthetic derivatives TFGF-18 selectively inhibit glycogen synthase kinase-3β (GSK-3β), a potential target of AD treatment.

PURPOSE

To investigate the neuroprotective effect of TFGF-18 against oxidative stress via the GSK-3β pathway in hydrogen peroxide (H2O2)-induced rat pheochromocytoma PC12 cells in vitro and scopolamine (SCOP)-induced AD mice in vivo.

METHOD

The oxidative stress of PC12 cells was induced by H2O2 (600 μM) and the effects of TFGF-18 (2 and 8 μM) or ISO (12.5 and 50 μM) were observed. The AD mouse model was induced by SCOP (3 mg/kg), and the effects of TFGF-18 (2 and 8 mg/kg), ISO (50 mg/kg), and donepezil (DNP) (3 mg/kg) were observed. DNP, a currently accepted drug for AD was used as a positive control. The neuronal cell damages were analyzed by flow cytometry, LDH assay, JC-1 assay and Nissl staining. The oxidative stress was evaluated by the detection of MDA, SOD, GPx and ROS. The level of ACh, and the activity of AChE, ChAT were detected by the assay kit. The expressions of Bax, Bcl-2, caspase3, cleaved-caspase3, p-AKT (Thr308), AKT, p-GSK-3β (Ser9), GSK-3β, Nrf2, and HO-1, as well as p-CREB (Ser133), CREB, and BDNF were analyzed by western blotting. Morris water maze test was performed to analyze learning and memory ability.

RESULTS

TFGF-18 inhibited neuronal damage and the expressions of Bax, caspase3 and cleaved-caspase3, and increased the expression of Bcl-2 in vitro and in vivo. The level of MDA and ROS were decreased while the activities of SOD and GPx were increased by TFGF-18. Moreover, TFGF-18 increased the p-AKT, p-GSK-3β (Ser9), Nrf2, HO-1, p-CREB, and BDNF expression reduced by H2O2 and SCOP. Meanwhile, MK2206, an AKT inhibitor, reversed the effect of TFGF-18 on the AKT/GSK-3β pathway. In addition, the cholinergic system (ACh, ChAT, and AChE) disorders were retrained and the learning and memory impairments were prevented by TFGF-18 in SCOP-induced AD mice.

CONCLUSIONS

TFGF-18 protects against neuronal cell damage and cognitive impairment by inhibiting oxidative stress via AKT/GSK-3β/Nrf2 pathway.

Mechanistic Insights and Potential Therapeutic Implications of NRF2 in Diabetic Encephalopathy

Diabetic encephalopathy (DE) is a complication of diabetes, especially type 2 diabetes (T2D), characterized by damage in the central nervous system and cognitive impairment, which has gained global attention. Despite the extensive research aimed at enhancing our understanding of DE, the underlying mechanism of occurrence and development of DE has not been established. Mounting evidence has demonstrated a close correlation between DE and various factors, such as Alzheimer's disease-like pathological changes, insulin resistance, inflammation, and oxidative stress. Of interest, nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor with antioxidant properties that is crucial in maintaining redox homeostasis and regulating inflammatory responses. The activation and regulatory mechanisms of NRF2 are a relatively complex process. NRF2 is involved in the regulation of multiple metabolic pathways and confers neuroprotective functions. Multiple studies have provided evidence demonstrating the significant involvement of NRF2 as a critical transcription factor in the progression of DE. Additionally, various molecules capable of activating NRF2 expression have shown potential in ameliorating DE. Therefore, it is intriguing to consider NRF2 as a potential target for the treatment of DE. In this review, we aim to shed light on the role and the possible underlying mechanism of NRF2 in DE. Furthermore, we provide an overview of the current research landscape and address the challenges associated with using NRF2 activators as potential treatment options for DE.

NRF2 Deficiency Promotes Ferroptosis of Astrocytes Mediated by Oxidative Stress in Alzheimer's Disease

Oxidative stress is involved in the pathogenesis of Alzheimer's disease (AD), which is linked to reactive oxygen species (ROS), lipid peroxidation, and neurotoxicity. Emerging evidence suggests a role of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a major source of antioxidant response elements in AD. The molecular mechanism of oxidative stress and ferroptosis in astrocytes in AD is not yet fully understood. Here, we aimed to investigate the mechanism by which Nrf2 regulates the ferroptosis of astrocytes in AD. We found decreased expression of Nrf2 and upregulated expression of the ROS marker NADPH oxidase 4 (NOX4) in the frontal cortex from patients with AD and in the cortex of 3×Tg mice compared to wildtype mice. We demonstrated that Nrf2 deficiency led to ferroptosis-dependent oxidative stress-induced ROS with downregulated heme oxygenase-1 and glutathione peroxidase 4 and upregulated cystine glutamate expression. Moreover, Nrf2 deficiency increased lipid peroxidation, DNA oxidation, and mitochondrial fragmentation in mouse astrocytes (mAS, M1800-57). In conclusion, these results suggest that Nrf2 deficiency promotes ferroptosis of astrocytes involving oxidative stress in AD.

Multifunctional Nanomaterials for Advancing Neural Interfaces: Recording, Stimulation, and Beyond

Neurotechnology has seen dramatic improvements in the last three decades. The major focus in the field has been to design electrical communication platforms with high spatial resolution, stability, and translatability for understanding and affecting neural pathways. The deployment of nanomaterials in bioelectronics has enhanced the capabilities of conventional approaches employing microelectrode arrays (MEAs) for electrical interfaces, allowing the construction of miniaturized, high-performance neuroelectronics (Garg, R.; et al. ACS Appl. Nano Mater. 2023, 6, 8495). While these advancements in the electrical neuronal interface have revolutionized neurotechnology both in scale and breadth, an in-depth understanding of neurons' interactions is challenging due to the complexity of the environments where the cells and tissues are laid. The activity of large, three-dimensional neuronal systems has proven difficult to accurately monitor and modulate, and chemical cell-cell communication is often completely neglected. Recent breakthroughs in nanotechnology have provided opportunities to use new nonelectric modes of communication with neurons and to significantly enhance electrical signal interface capabilities. The enhanced electrochemical activity and optical activity of nanomaterials owing to their nonbulk electronic properties and surface nanostructuring have seen extensive utilization. Nanomaterials' enhanced optical activity enables remote neural state modulation, whereas the defect-rich surfaces provide an enormous number of available electrocatalytic sites for neurochemical detection and electrochemical modulation of cell microenvironments through Faradaic processes. Such unique properties can allow multimodal neural interrogation toward generating closed-loop interfaces with access to more complete neural state descriptors. In this Account, we will review recent advances and our efforts spearheaded toward utilizing nanostructured electrodes for enhanced bidirectional interfaces with neurons, the application of unique hybrid nanomaterials for remote nongenetic optical stimulation of neurons, tunable nanomaterials for highly sensitive and selective neurotransmitter detection, and the utilization of nanomaterials as electrocatalysts toward electrochemically modulating cellular activity. We highlight applications of these technologies across cell types through nanomaterial engineering with a focus on multifunctional graphene nanostructures applied though several modes of neural modulation but also an exploration of broad material classes for maximizing the potency of closed-loop bioelectronics.

Irbesartan mitigates the impact of cyclophosphamide-induced acute neurotoxicity in rats: Shedding highlights on NLRP3 inflammasome/CASP-1 pathway-driven immunomodulation

IIrbesartan (IRB), an angiotensin II type 1 receptor (AT1R) antagonist, has been widely employed in the medical field for its effectiveness in managing hypertension. However, there have been no documented investigations regarding the immunostimulatory properties of IRB. To address this gap, this study has been performed to assess the neuroprotective impact of IRB as an immunostimulatory agent in mitigating acute neurotoxicity induced by cyclophosphamide (CYP) in rats. mRNA levels of nuclear factor erythroid 2 (Nrf-2), interleukin (IL)-18, IL-1β, and MMP-1 have been assessed using quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, the levels of malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) has been evaluated to assess the oxidative stress. Additionally, macrophage inflammatory protein 2 (MIP2) has been evaluated using enzyme-linked immunosorbent assay (ELISA). Western blotting has been used to investigate the protein expression of nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) and caspase-1 (CASP-1), along with an assessment of histopathological changes. Administration of IRB protected against oxidative stress by augmenting the levels of GSH and SOD as well as reducing MDA level. Also, administration of IRB led to a diminishment in the brain levels of MIP2 and MMP1. Furthermore, it led to a suppression of IL-1β and IL-18 levels, which are correlated with a reduction in the abundance of NLRP3 and subsequently CASP-1. This study provides new insights into the immunomodulatory effects of IRB in the context of CYP-induced acute neurotoxicity. Specifically, IRB exerts its effects by reducing oxidative stress, neuroinflammation, inhibiting chemokine recruitment, and mitigating neuronal degeneration through the modulation of immune markers. Therefore, it can be inferred that the use of IRB as an immunomodulator has the potential to effectively mitigate immune disorders associated with inflammation.

Neuroprotective Effects of Olive Oil: A Comprehensive Review of Antioxidant Properties

Neurodegenerative diseases are a significant challenge to global healthcare, and oxidative stress plays a crucial role in their development. This paper presents a comprehensive analysis of the neuroprotective potential of olive oil, with a primary focus on its antioxidant properties. The chemical composition of olive oil, including key antioxidants, such as oleuropein, hydroxytyrosol, and oleocanthal, is systematically examined. The mechanisms by which these compounds provide neuroprotection, including counteracting oxidative damage and modulating neuroprotective pathways, are explored. The neuroprotective efficacy of olive oil is evaluated by synthesizing findings from various sources, including in vitro studies, animal models, and clinical trials. The integration of olive oil into dietary patterns, particularly its role in the Mediterranean diet, and its broader implications in neurodegenerative disease prevention are also discussed. The challenges in translating preclinical findings to clinical applications are acknowledged and future research directions are proposed to better understand the potential of olive oil in mitigating the risk of neurodegenerative conditions. This review highlights olive oil not only as a dietary component, but also as a promising candidate in preventive neurology, advocating for further investigation in the context of neurodegenerative diseases.

Phytomedicine for neurodegenerative diseases: The road ahead

Neurodegenerative disorders (NDs) are among the most common causes of death across the globe. NDs are characterized by progressive damage to CNS neurons, leading to defects in specific brain functions such as memory, cognition, and movement. The most common NDs are Parkinson's, Alzheimer's, Huntington's, and amyotrophic lateral sclerosis (ALS). Despite extensive research, no therapeutics or medications against NDs have been proven to be effective. The current treatment of NDs involving symptom-based targeting of the disease pathogenesis has certain limitations, such as drug resistance, adverse side effects, poor blood-brain barrier permeability, and poor bioavailability of drugs. Some studies have shown that plant-derived natural compounds hold tremendous promise for treating and preventing NDs. Therefore, the primary objective of this review article is to critically analyze the properties and potency of some of the most studied phytomedicines, such as quercetin, curcumin, epigallocatechin gallate (EGCG), apigenin, and cannabinoids, and highlight their advantages and limitations for developing next-generation alternative treatments against NDs. Further extensive research on pre-clinical and clinical studies for developing plant-based drugs against NDs from bench to bedside is warranted.

Beneficial effect of lupeol and metformin in mouse model of intracerebroventricular streptozotocin induced dementia

This study examines the effectiveness of lupeol and metformin in a mouse model of dementia generated by intracerebroventricular streptozotocin (i.c.v., STZ). Dementia was induced in Swiss mice with the i.c.v. administration of STZ at a dosage of 3 mg/kg on the first and third day. The assessment of dementia involved an examination of the Morris Water Maze (MWM) performance, as well as a number of biochemical and histological studies. STZ treatment resulted in significant decrease in MWM performance; various biochemical alterations (increase in brain acetyl cholinesterase (AChE) activity, thiobarbituric acid reactive species (TBARS), nitrite/nitrate, and reduction in nuclear factor erythroid 2 related factor-2 (Nrf-2), reduced glutathione (GSH) levels) and neuroinflammation [increased myeloperoxidase (MPO) activity & neutrophil infiltration]. The administration of Lupeol (50 mg/kg & 100 mg/kg; p.o.) and Metformin (150 mg/kg & 300 mg/kg; p.o.) demonstrated a considerable reduction in the behavioral, biochemical, and histological alterations produced by STZ. Low dose combination of lupeol (50 mg/kg; p.o.) and Metformin (150 mg/kg; p.o.) produced more pronounced effect than that of high doses of either agent alone. It is concluded that Lupeol and Metformin has shown efficacy in dementia with possible synergism between the two and can be explored as potential therapeutic agents for managing dementia of Alzheimer's disease (AD) type.

Effect of time-restricted eating and intermittent fasting on cognitive function and mental health in older adults: A systematic review

Objective

Emerging evidence suggests that dietary interventions hold promise for promoting cognitive function and mental well-being in aging populations. This systematic review aimed to examine the potential relationship between Time-Restricted Eating (TRE) and Intermittent Fasting (IFA) with cognitive function and mental health in older adults.

Methods

A thorough exploration was undertaken on electronic databases such as PubMed, Scopus, Web of Science, Science Direct, and Google Scholar, up to October 2023, following PRISMA standards. The evaluation of the quality and potential bias in the incorporated articles involved the use of the Newcastle-Ottawa Scale and Consolidated Standards of Reporting Trials (CONSORT).

Results

From a total of 539 articles initially identified, eight studies met the eligibility criteria for inclusion in this review. Out of these eight studies, six focused on cognitive function, and 2 focused on mental health. The reviewed articles encompassed a wide range of population sizes, with the number of older adults studied varying from 10 to 1357, reflecting a diverse cohort of individuals. Conclusions.The findings suggest that TRE and IFA may have a positive impact on cognitive function and mental health in this population. However, additional research is needed to fully comprehend this relationship. Therefore, future research should specifically examine factors such as the duration and timing of the eating window in TRE, as well as the physical condition of older adults, to provide a more nuanced understanding of the cognitive and mental health benefits of TRE and IFA in older adults.

The potential neuroprotective of luteolin against acetamiprid-induced neurotoxicity in the rat cerebral cortex

Acetamiprid is a class of neuroactive insecticides widely used to control insect pests. The current study aimed to investigate the potential neuroprotective effects of luteolin against acetamiprid-induced neurotoxicity in the rat cerebral cortex. Four equal groups of adult male rats (10 in each): control, acetamiprid (40 mg/kg for 28 days), luteolin (50 mg/kg for 28 days), and acetamiprid+luteolin cotreatment were used. Acetamiprid was shown to alter the oxidative state by increasing oxidant levels [nitric oxide (NO) and malondialdehyde (MDA)] and decreasing antioxidants [glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), and catalase-(CAT)], with increased activity of nuclear factor erythroid 2-related factor 2-(Nrf2). Likewise, acetamiprid increases the inflammatory response, as evidenced by increased interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and nuclear factor kappa B-(NF-κB). In contrast, the treatment with luteolin brought these markers back to levels close to normal, showing that it protects neurocytes from oxidative damage and the neuroinflammation effects of acetamiprid-induced inflammation. Luteolin also demonstrated a neuroprotective role via the modulation of acetylcholinesterase (AChE) activity in the cerebral cortex tissue. Histopathology showed severe neurodegenerative changes, and apoptotic cells were seen in the acetamiprid-induced cerebral cortex layer, which was evident by increased protein expression levels of Bax and caspase-3 and decreased Bcl-2 levels. Histochemistry confirmed the neuronal degeneration, as proven by the change in neurocyte colour from brown to black when stained with a silver stain. Luteolin may have a neuroprotective effect against biochemical and histopathological changes induced by acetamiprid in the rat cerebral cortex.

Inhibiting the Keap1/Nrf2 Protein-Protein Interaction with Protein-Like Polymers

Successful and selective inhibition of the cytosolic protein-protein interaction (PPI) between nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associating protein 1 (Keap1) can enhance the antioxidant response, with the potential for a therapeutic effect in a range of settings including in neurodegenerative disease (ND). Small molecule inhibitors have been developed, yet many have off-target effects, or are otherwise limited by poor cellular permeability. Peptide-based strategies have also been attempted to enhance specificity, yet face challenges due to susceptibility to degradation and lack of cellular penetration. Herein, these barriers are overcome utilizing a polymer-based proteomimetics. The protein-like polymer (PLP) consists of a synthetic, lipophilic polymer backbone displaying water soluble Keap1-binding peptides on each monomer unit forming a brush polymer architecture. The PLPs are capable of engaging Keap1 and displacing the cellular protective transcription factor Nrf2, which then translocates to the nucleus, activating the antioxidant response element (ARE). PLPs exhibit increased Keap1 binding affinity by several orders of magnitude compared to free peptides, maintain serum stability, are cell-penetrant, and selectively activate the ARE pathway in cells, including in primary cortical neuronal cultures. Keap1/Nrf2-inhibitory PLPs have the potential to impact the treatment of disease states associated with dysregulation of oxidative stress, such as NDs.

Oxidative stress involvement in the molecular pathogenesis and progression of multiple sclerosis: a literature review

Multiple sclerosis (MS) is an autoimmune debilitating disease of the central nervous system caused by a mosaic of interactions between genetic predisposition and environmental factors. The pathological hallmarks of MS are chronic inflammation, demyelination, and neurodegeneration. Oxidative stress, a state of imbalance between the production of reactive species and antioxidant defense mechanisms, is considered one of the key contributors in the pathophysiology of MS. This review is a comprehensive overview of the cellular and molecular mechanisms by which oxidant species contribute to the initiation and progression of MS including mitochondrial dysfunction, disruption of various signaling pathways, and autoimmune response activation. The detrimental effects of oxidative stress on neurons, oligodendrocytes, and astrocytes, as well as the role of oxidants in promoting and perpetuating inflammation, demyelination, and axonal damage, are discussed. Finally, this review also points out the therapeutic potential of various synthetic antioxidants that must be evaluated in clinical trials in patients with MS.

Neuroprotective effect of acetoxypachydiol against oxidative stress through activation of the Keap1-Nrf2/HO-1 pathway

BACKGROUND

Excessive oxidative stress in the brain is an important pathological factor in neurological diseases. Acetoxypachydiol (APHD) is a lipophilic germacrane-type diterpene extracted as a major component from different species of brown algae within the genus Dictyota. There have been no previous reports on the pharmacological activity of APHD. The present research aims to explore the potential neuroprotective properties of APHD and its underlying mechanisms.

METHODS

The possible mechanism of APHD was predicted using a combination of molecular docking and network pharmacological analysis. PC12 cells were induced by H2O2 and oxygen-glucose deprivation/reoxygenation (OGD/R), respectively. Western blot, flow cytometry, immunofluorescence staining, and qRT-PCR were used to investigate the antioxidant activity of APHD. The HO-1 inhibitor ZnPP and Nrf2 gene silencing were employed to confirm the influence of APHD on the signaling cascade involving HO-1, Nrf2, and Keap1 in vitro.

RESULTS

APHD exhibited antioxidant activity in both PC12 cells subjected to H2O2 and OGD/R conditions by downregulating the release of LDH, the concentrations of MDA, and ROS, and upregulating SOD, GSH-Px, and GSH concentrations. APHD could potentially initiate the Keap1-Nrf2/HO-1 signaling cascade, according to the findings from network pharmacology evaluation and molecular docking. Furthermore, APHD was observed to increase Nrf2 and HO-1 expression at both mRNA and protein levels, while downregulating the protein concentrations of Keap1. Both Nrf2 silencing and treatment with ZnPP reversed the neuroprotective effects of APHD.

CONCLUSIONS

APHD activated antioxidant enzymes and downregulated the levels of LDH, MDA, and ROS in two cell models. The neuroprotective effect is presumably reliant on upregulation of the Keap1-Nrf2/HO-1 pathway. Taken together, APHD from brown algae of the genus Dictyota shows potential as a candidate for novel neuroprotective agents.

Neuroprotective Effects of Intermittent Fasting in the Aging Brain

BACKGROUND

A major risk factor for neurodegenerative disorders is old age. Nutritional interventions that delay aging, such as calorie restriction (CR) and intermittent fasting (IF), as well as pharmaceuticals that affect the pathways linking nutrition and aging processes, have been developed in recent decades and have been shown to alleviate the effects of aging on the brain.

SUMMARY

CR is accomplished by alternating periods of ad libitum feeding and fasting. In animal models, IF has been shown to increase lifespan and slow the progression and severity of age-related pathologies such as cardiovascular and neurodegenerative diseases and cancer. According to recent research, dietary changes can help older people with dementia retain brain function. However, the mechanisms underlying the neuroprotective effect of IF on the aging brain and related questions in this area of study (i.e., the potential of IF to treat neurodegenerative disorders) remain to be examined.

KEY MESSAGES

This review addresses the hypothesis that IF may have translational potential in protecting the aged brain while summarizing the research supporting the putative neuroprotective mechanisms of IF in animal models. Additionally, given the emerging understanding of the connection between aging and dementia, our investigations may offer a fresh perspective on the use of dietary interventions for enhancing brain function and preventing dementia in elderly individuals. Finally, the absence of guidelines regarding the application of IF in patients hampers its broad utilization in clinical practice, and further studies are needed to improve our knowledge of the long-term effects of IF on dementia before it can be widely prescribed. In conclusion, IF may be an ancillary intervention for preserving memory and cognition in elderly individuals.

NMDA Receptor Antagonist Memantine Ameliorates Experimental Autoimmune Encephalomyelitis in Aged Rats

Aging is closely related to the main aspects of multiple sclerosis (MS). The average age of the MS population is increasing and the number of elderly MS patients is expected to increase. In addition to neurons, N-methyl-D-aspartate receptors (NMDARs) are also expressed on non-neuronal cells, such as immune cells. The aim of this study was to investigate the role of NMDARs in experimental autoimmune encephalomyelitis (EAE) in young and aged rats. Memantine, a non-competitive NMDAR antagonist, was administered to young and aged Dark Agouti rats from day 7 after immunization. Antagonizing NMDARs had a more favourable effect on clinical disease, reactivation, and apoptosis of CD4+ T cells in the target organ of aged EAE rats. The expression of the fractalkine receptor CX3CR1 was increased in memantine-treated rats, but to a greater extent in aged rats. Additionally, memantine increased Nrf2 and Nrf2-regulated enzymes' mRNA expression in brain tissue. The concentrations of superoxide anion radicals, malondialdehyde, and advanced oxidation protein products in brain tissue were consistent with previous results. Overall, our results suggest that NMDARs play a more important role in the pathogenesis of EAE in aged than in young rats.

Nrf2 activation: a key mechanism in stem cell exosomes-mediated therapies

Exosomes are nano-sized membrane extracellular vesicles which can be released from various types of cells. Exosomes originating from inflammatory or injured cells can have detrimental effects on recipient cells, while exosomes derived from stem cells not only facilitate the repair and regeneration of damaged tissues but also inhibit inflammation and provide protective effects against various diseases, suggesting they may serve as an alternative strategy of stem cells transplantation. Exosomes have a fundamental role in communication between cells, through the transfer of proteins, bioactive lipids and nucleic acids (like miRNAs and mRNAs) between cells. This transfer significantly impacts both the physiological and pathological functions of recipient cells. Nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor, is able to mitigate damage caused by oxidative stress and inflammation through various signaling pathways. The positive effects resulting from the activation of the Nrf2 signaling pathway in different disorders have been documented in various types of literature. Studies have confirmed that exosomes derived from stem cells could act as Nrf2 effective agonists. However, limited studies have explored the Nrf2 role in the therapeutic effects of stem cell-derived exosomes. This review provides a comprehensive overview of the existing knowledge concerning the role of Nrf2 signaling pathways in the impact exerted by stem cell exosomes in some common diseases.

Ferroptosis regulation through Nrf2 and implications for neurodegenerative diseases

This article provides an overview of the background knowledge of ferroptosis in the nervous system, as well as the key role of nuclear factor E2-related factor 2 (Nrf2) in regulating ferroptosis. The article takes Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) as the starting point to explore the close association between Nrf2 and ferroptosis, which is of clear and significant importance for understanding the mechanism of neurodegenerative diseases (NDs) based on oxidative stress (OS). Accumulating evidence links ferroptosis to the pathogenesis of NDs. As the disease progresses, damage to the antioxidant system, excessive OS, and altered Nrf2 expression levels, especially the inhibition of ferroptosis by lipid peroxidation inhibitors and adaptive enhancement of Nrf2 signaling, demonstrate the potential clinical significance of Nrf2 in detecting and identifying ferroptosis, as well as targeted therapy for neuronal loss and mitochondrial dysfunction. These findings provide new insights and possibilities for the treatment and prevention of NDs.

A Neglected Gene: The Role of the ANG Gene in the Pathogenesis of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease with a poor prognosis. To date, more than 40 ALS-related genes have been identified. However, there is still a lack of targeted therapeutic drugs for the treatment of ALS, especially for patients with acute onset and severe disease. A series of studies reported missense heterozygous mutations with loss of function in the coding region of the ANG gene in ALS patients. ANG deficiency is related to the pathogenesis of ALS, but the underlying mechanism has not been determined. This article aimed to synthesize and consolidate the knowledge of the pathological mechanism of ALS induced by ANG mutation and provide a theoretical basis for ALS diagnosis and targeted therapy. This article further delves into the mechanisms underlying the current understanding of the structure and function of the ANG gene, the association between ANG and ALS, and its pathogenesis. Mutations in ANG may lead to the development of ALS through the loss of neuroprotective function, induction of oxidative stress, or inhibition of rRNA synthesis. ANG mutations and genetic and environmental factors may cause disease heterogeneity and more severe disease than in ALS patients with the wild-type gene. Exploring this mechanism is expected to provide a new approach for ALS treatment through increasing ANG expression or angiogenin activity. However, the related study is still in its infancy; therefore, this article also highlights the need for further exploration of the application of ANG gene mutations in clinical trials and animal experiments is needed to achieve improved early diagnosis and treatment of ALS.

Nrf2 Signaling Pathway: a Potential Therapeutic Target in Combating Oxidative Stress and Neurotoxicity in Chemotherapy-Induced Cognitive Impairment

Chemotherapy-induced cognitive impairment (CICI) is one of the major adverse effects of antineoplastic drugs, which decrease the quality of life in cancer survivors. Extensive experimental and clinical research suggests that chemotherapeutic drugs generate an enormous amount of reactive oxygen species (ROS), contributing to oxidative stress, neuroinflammation, blood-brain barrier (BBB) disruption, and neuronal death, eventually leading to CICI. Despite the progress in exploring different pathological mechanisms of CICI, effective treatment to prevent CICI progression has not been developed yet. Nrf2 is the principal transcription factor that regulates cellular redox balance and inflammation-related gene expression. Emerging evidence suggests that upregulation of Nrf2 and its target genes could suppress oxidative stress, and neuroinflammation, restore BBB integrity, and increase neurogenesis. This review discusses the role of Nrf2 in CICI, how it responds to oxidative stress, inflammation, neurotoxicity, and potential Nrf2 activators that could be used to enhance Nrf2 activation in CICI.

Role of Astrogliosis in the Pathogenesis of Parkinson's Disease: Insights into Astrocytic Nrf2 Pathway as a Potential Therapeutic Target

Recently, Parkinson's disease (PD) has become a remarkable burden on families and society with an acceleration of population aging having several pathological hallmarks such as dopaminergic neuronal loss of the substantia nigra pars compacta, α-synucleinopathy, neuroinflammation, autophagy, last but not the least astrogliosis. Astrocyte, star-shaped glial cells perform notable physiological functions in the brain through several molecular and cellular mechanisms including nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. It has been well established that the downregulation of the astrocytic Nrf2 signaling pathway plays a crucial role in the pathogenesis of PD because it is a master regulator of cellular defense mechanism along with a regulator of numerous detoxifying and antioxidant enzymes gene expression. Fascinatingly, upregulation of the astrocytic Nrf2 signaling pathway attenuates the degeneration of nigrostriatal neurons, restores neuronal proliferation, rejuvenates astrocytic functions, and exhibits neuroprotective effects via numerous cellular and molecular mechanisms in the PD-like brain of the experimental animal. Here, we discuss the numerous in-vitro and in-vivo studies that evaluate the neuroprotective potential of the astrocytic Nrf2 signaling pathway against experimentally-induced PD-like manifestation. In conclusion, based on available preclinical reports, it can be assumed that the astrocytic Nrf2 signaling pathway could be an alternative target in the drug discovery process for the prevention, management, and treatment of PD.

Proximity proteomic analysis of the NRF family reveals the Parkinson's disease protein ZNF746/PARIS as a co-complexed repressor of NRF2

The nuclear factor erythroid 2-related factor 2 (NRF2) transcription factor activates cytoprotective and metabolic gene expression in response to various electrophilic stressors. Constitutive NRF2 activity promotes cancer progression, whereas decreased NRF2 function contributes to neurodegenerative diseases. We used proximity proteomic analysis to define protein networks for NRF2 and its family members NRF1, NRF3, and the NRF2 heterodimer MAFG. A functional screen of co-complexed proteins revealed previously uncharacterized regulators of NRF2 transcriptional activity. We found that ZNF746 (also known as PARIS), a zinc finger transcription factor implicated in Parkinson's disease, physically associated with NRF2 and MAFG, resulting in suppression of NRF2-driven transcription. ZNF746 overexpression increased oxidative stress and apoptosis in a neuronal cell model of Parkinson's disease, phenotypes that were reversed by chemical and genetic hyperactivation of NRF2. This study presents a functionally annotated proximity network for NRF2 and suggests a link between ZNF746 overexpression in Parkinson's disease and inhibition of NRF2-driven neuroprotection.

KEAP1 polymorphisms and neurodevelopmental outcomes in children with exposure to prenatal MeHg from the Seychelles Child Development Study Nutrition Cohort 2

BACKGROUND

Humans differ in the metabolism of the neurotoxicant methyl mercury (MeHg). This variation may be partially due to variation in genes encoding the transcription factor Nuclear factor E2-related factor 2 (NRF2) and its negative regulator Kelch-like ECH-Associated Protein 1 (KEAP1), which regulate glutathione and related transporter and antioxidant proteins that play a role in the metabolism and neurotoxicity of MeHg.

AIM

To elucidate a potential risk from genetic variation in NFE2L2 (encoding NRF2) and KEAP1 toward prenatal mercury exposure and child neurodevelopmental outcomes at 20 months and 7 years of age in a population with variable prenatal exposure to MeHg from maternal fish consumption.

MATERIAL AND METHODS

Nutrition Cohort 2 is a mother-child cohort in the Republic of Seychelles. Children were genotyped for NFE2L2 (rs2364723, rs13001694) and KEAP1 (rs8113472, rs9676881) polymorphisms (N = 1285 after removing siblings). Total mercury (Hg) was measured in cord blood as a biomarker for prenatal MeHg exposure. Child neurodevelopmental outcomes included the Bayley Scales of Infant Development II administered at 20 months of age, and outcomes across multiple neurodevelopmental domains from 14 tests administered in children and 3 instruments completed by parents when children were 7 years of age.

RESULTS

The mean cord blood MeHg concentration was 34 (95% CI 11, 75) µg/L. None of the four polymorphisms had a significant association (p < 0.05) with either cord MeHg or neurodevelopmental test results at 20 months. There were no significant associations between either NFE2L2 polymorphism and any developmental test scores. At 7 years, children carrying KEAP1 rs8113472 CA showed significantly worse performance on psychomotor function than children with the CC variant (finger tapping, dominant hand: β - 1.19, SE 0.34; finger tapping, non-dominant hand: β - 0.92, SE 0.31) and worse social communication (SCQ Total: β 0.65, SE 0.27). Children carrying rs8113472 AA, versus children with CC, showed significantly better performance on social communication (SRS Total: β - 8.88, SE 3.60). Children carrying KEAP1 rs9676881 AG, versus children with GG, showed significantly worse performance on psychomotor function (trailmaking A time: β 8.66, SE 3.37) and cognition (KBIT Matrices: β - 0.96, SE 0.36).

CONCLUSION

No associations between NFE2L2 and KEAP1 polymorphisms and MeHg concentration were identified. However, at 7 years, KEAP1 polymorphisms were associated with differences in neurodevelopmental outcomes in children from a population with high fish intake.

Polyphenols in Inner Ear Neurobiology, Health and Disease: From Bench to Clinics

There is substantial experimental and clinical interest in providing effective ways to both prevent and slow the onset of hearing loss. Auditory hair cells, which occur along the basilar membrane of the cochlea, often lose functionality due to age-related biological alterations, as well as from exposure to high decibel sounds affecting a diminished/damaged auditory sensitivity. Hearing loss is also seen to take place due to neuronal degeneration before or following hair cell destruction/loss. A strategy is necessary to protect hair cells and XIII cranial/auditory nerve cells prior to injury and throughout aging. Within this context, it was proposed that cochlea neural stem cells may be protected from such aging and environmental/noise insults via the ingestion of protective dietary supplements. Of particular importance is that these studies typically display a hormetic-like biphasic dose-response pattern that prevents the occurrence of auditory cell damage induced by various model chemical toxins, such as cisplatin. Likewise, the hormetic dose-response also enhances the occurrence of cochlear neural cell viability, proliferation, and differentiation. These findings are particularly important since they confirmed a strong dose dependency of the significant beneficial effects (which is biphasic), whilst having a low-dose beneficial response, whereas extensive exposures may become ineffective and/or potentially harmful. According to hormesis, phytochemicals including polyphenols exhibit biphasic dose-response effects activating low-dose antioxidant signaling pathways, resulting in the upregulation of vitagenes, a group of genes involved in preserving cellular homeostasis during stressful conditions. Modulation of the vitagene network through polyphenols increases cellular resilience mechanisms, thus impacting neurological disorder pathophysiology. Here, we aimed to explore polyphenols targeting the NF-E2-related factor 2 (Nrf2) pathway to neuroprotective and therapeutic strategies that can potentially reduce oxidative stress and inflammation, thus preventing auditory hair cell and XIII cranial/auditory nerve cell degeneration. Furthermore, we explored techniques to enhance their bioavailability and efficacy.

Astrocytic Nrf2 Mediates the Neuroprotective and Anti-Inflammatory Effects of Nootkatone in an MPTP-Induced Parkinson's Disease Mouse Model

This study aims to investigate the neuroprotective effects of nootkatone (NKT), a sesquiterpenoid compound isolated from grapefruit, in an MPTP-induced Parkinson's disease (PD) mouse model. NKT restored MPTP-induced motor impairment and dopaminergic neuronal loss and increased the expression of neurotrophic factors like BDNF, GDNF, and PGC-1α. In addition, NKT inhibited microglial and astrocyte activation and the expression of pro-inflammatory markers like iNOS, TNF-α, and IL-1β and oxidative stress markers like 4-HNE and 8-OHdG. NKT increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2)-driven antioxidant enzymes like HO-1 and NQO-1 in astrocytes, but not in neurons or microglia in MPTP-treated mice. To investigate whether Nrf2 mediates the anti-inflammatory, antioxidant, or neuroprotective effects of NKT, mice were pretreated with Nrf2-specific inhibitor brusatol (BT) prior to NKT treatment. BT attenuated the NKT-mediated inhibition of 4-HNE and 8-OHdG and the number of Nrf2+/HO-1+/NQO1+ cells co-localized with GFAP+ astrocytes in the substantia nigra of MPTP-treated mice. In addition, BT reversed the effects of NKT on dopaminergic neuronal cell death, neurotrophic factors, and pro-/anti-inflammatory cytokines in MPTP-treated mice. Collectively, these data suggest that astrocytic Nrf2 and its downstream antioxidant molecules play pivotal roles in mediating the neuroprotective and anti-inflammatory effects of NKT in an MPTP-induced PD mouse model.

Small molecules targeting different cellular pathologies for the treatment of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease in which the motor neuron circuitry displays progressive degeneration, affecting mostly the motor neurons in the brain and in the spinal cord. There are no effective cures, albeit three drugs, riluzole, edaravone, and AMX0035 (a combination of sodium phenylbutyrate and taurursodiol), have been approved by the Food and Drug Administration, with limited improvement in patients. There is an urgent need to build better and more effective treatment strategies for ALS. Since the disease is very heterogenous, numerous approaches have been explored, such as targeting genetic mutations, decreasing oxidative stress and excitotoxicity, enhancing mitochondrial function and protein degradation mechanisms, and inhibiting neuroinflammation. In addition, various chemical libraries or previously identified drugs have been screened for potential repurposing in the treatment of ALS. Here, we review previous drug discovery efforts targeting a variety of cellular pathologies that occur from genetic mutations that cause ALS, such as mutations in SOD1, C9orf72, FUS, and TARDP-43 genes. These mutations result in protein aggregation, which causes neuronal degeneration. Compounds used to target cellular pathologies that stem from these mutations are discussed and comparisons among different preclinical models are presented. Because the drug discovery landscape for ALS and other motor neuron diseases is changing rapidly, we also offer recommendations for a novel, more effective, direction in ALS drug discovery that could accelerate translation of effective compounds from animals to patients.

Drug repurposing on Alzheimer's disease through modulation of NRF2 neighborhood

Alzheimer's disease (AD) is an age-dependent neurodegenerative disorder and the most common cause of cognitive decline. The alarming epidemiological features of Alzheimer's disease, combined with the high failure rate of candidate drugs tested in the preclinical phase, impose more intense investigations for new curative treatments. NRF2 (Nuclear factor-erythroid factor 2-related factor 2) plays a critical role in the inflammatory response and in the cellular redox homeostasis and provides cytoprotection in several diseases including those in the neurodegeneration spectrum. These roles suggest that NRF2 and its directly associated proteins may be novel attractive therapeutic targets in the fight against AD. In this study, through a systemics perspective, we propose an in silico drug repurposing approach for AD, based on the NRF2 interactome and regulome, with the aim of highlighting possible repurposed drugs for AD. Using publicly available information based on differential expressions of the NRF2-neighborhood in AD and through a computational drug repurposing pipeline, we derived to a short list of candidate repurposed drugs and small molecules that affect the expression levels of the majority of NRF2-partners. The relevance of these findings was assessed in a four-step computational meta-analysis including i) structural similarity comparisons with currently ongoing NRF2-related drugs in clinical trials ii) evaluation based on the NRF2-diseasome iii) comparison of relevance between targeted pathways of shortlisted drugs and NRF2-related drugs in clinical trials and iv) further comparison with existing knowledge on AD and NRF2-related drugs in clinical trials based on their known modes of action. Overall, our analysis yielded in 5 candidate repurposed drugs for AD. In cell culture, these 5 candidates activated a luciferase reporter for NRF2 activity and in hippocampus derived TH22 cells they increased NRF2 protein levels and the NRF2 transcriptional signatures as determined by increased expression of its downstream target heme oxygenase 1. We expect that our proposed candidate repurposed drugs will be useful for further research and clinical translation for AD.

Lactic Acid Bacteria-Derived Exopolysaccharides Mitigate the Oxidative Response via the NRF2-KEAP1 Pathway in PC12 Cells

Parabiotics, including L-EPSs, have been administered to patients with neurodegenerative disorders. However, the antioxidant properties of L-EPSs against H2O2-induced oxidative stress in PC12 cells have not been studied. Herein, we aimed to investigate the antioxidant properties of the L-EPSs, their plausible targets, and their mechanism of action. We first determined the amount of L-EPSs in Lactobacillus delbrueckii ssp. bulgaricus B3 and Lactiplantibacillus plantarum GD2 using spectrophotometry. Afterwards, we studied their effects on TDH, TOS/TAS, antioxidant enzyme activities, and intracellular ROS level. Finally, we used qRT-PCR and ELISA to determine the effects of L-EPSs on the NRF2-KEAP1 pathway. According to our results, the L-EPS groups exhibited significantly higher total thiol activity, native thiol activity, disulfide activity, TAS levels, antioxidant enzyme levels, and gene expression levels (GCLC, HO-1, NRF2, and NQO1) than did the H2O2 group. Additionally, the L-EPS groups caused significant reductions in TOS levels and KEAP1 gene expression levels compared with those in the H2O2 group. Our results indicate that H2O2-induced oxidative stress was modified by L-EPSs. Thus, we revealed that L-EPSs, which regulate H2O2-induced oxidative stress, could have applications in the field of neurochemistry.

The untapped potential of targeting NRF2 in neurodegenerative disease

Since its initial discovery almost three decades ago, the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) has been shown to regulate a host of downstream transcriptional responses and play a critical role in preventing or promoting disease progression depending on the context. Critically, while the importance of proper nuclear factor erythroid 2-related factor 2 function has been demonstrated across a variety of pathological settings, the ability to progress NRF2-targeted therapeutics to clinic has remained frustratingly elusive. This is particularly true in the case of age-related pathologies, where nuclear factor erythroid 2-related factor 2 is a well-established mitigator of many of the observed pathogenic effects, yet options to target this pathway remain limited. Along these lines, loss of nuclear factor erythroid 2-related factor 2 function has clearly been shown to enhance neuropathological outcomes, with enhancing nuclear factor erythroid 2-related factor 2 pathway activation to prevent neurodegenerative/neurological disease progression continuing to be an active area of interest. One critical obstacle in generating successful therapeutics for brain-related pathologies is the ability of the compound to cross the blood brain barrier (BBB), which has also hampered the implementation of several promising nuclear factor erythroid 2-related factor 2 inducers. Another limitation is that many nuclear factor erythroid 2-related factor 2 activators have undesirable off-target effects due to their electrophilic nature. Despite these constraints, the field has continued to evolve, and several viable means of targeting nuclear factor erythroid 2-related factor 2 in a neuropathological context have emerged. In this perspective, we will briefly discuss the key findings and promising therapeutic options that have been discovered to date, as well as highlight emerging areas of NRF2-neurodegeneration research that provide hope for successfully targeting this pathway in the future.

Insight into Nrf2: a bibliometric and visual analysis from 2000 to 2022

Background: Nrf2 plays a pivotal role in governing the antioxidant defense system, triggering the transcription of diverse genes involved in cellular protection. Its role in mitigating oxidative damage and modulating inflammatory processes has made Nrf2 an attractive target for therapeutic interventions. Despite the growing interest in Nrf2 research, a bibliometric analysis is relatively rare. This study aimed to clarify Nrf2's role in multiple diseases, identify emerging trends and hotspots using bibliometric analysis, and provide valuable insights and potential directions for future therapeutic interventions. Methods: The Science Citation Index of Web of Science Core library from 2000 to 2022 was searched on 22 October 2022. Use Microsoft Excel, CiteSpace, Bibliometrix, and VOS viewers for data collection and visualization of research focus and trends. Results: A vast collection of 22,040 research studies on Nrf2 published between 2000 and 2022 were identified. Nrf2 research has seen significant growth globally from 2000 to 2022. China leaded in publication numbers (9,623, 43.66%), while the United States dominated in citation frequency with 261,776 citations. China Medical University was the most productive institutions (459, 2.08%). Masayuki Yamamoto topped in publications (307), while Itoh K. ranked first in citations with 3669. Free Radical Biology and Medicine was the journal with the most studies and citations on Nrf2 (613, 29,687 citations). The analysis of keyword clustering enhanced the categorization of topics and can be summarized as oxidative stress, cancer, disorders in glycolipid metabolism, inflammation, and neurological conditions. Conclusion: China and the United States are the pioneers in Nrf2 research. Recently, there has been a comprehensive exploration of Nrf2 involving both experimental and clinical aspects, as well as mechanisms and therapeutic applications. Investigating novel molecular mechanisms, including NF-κB, Ho1, and Keap1, and developing enhanced, targeted Nrf2 activators or inhibitors to uncover the interplay among cancer, glycolipid metabolic disorder, inflammation, and neurological disorders will be upcoming trends and hotspots.

Limited expression of Nrf2 in neurons across the central nervous system

Nrf2, encoded by the gene Nfe2l2, is a broadly expressed transcription factor that regulates gene expression in response to reactive oxygen species (ROS) and oxidative stress. It is commonly referred to as a ubiquitous pathway, but this generalization overlooks work indicating that Nrf2 is essentially unexpressed in some neuronal populations. To explore whether this pattern extends throughout the central nervous system (CNS), we quantified Nfe2l2 expression and chromatin accessibility at the Nfe2l2 locus across multiple single cell datasets. In both the mouse and human CNS, Nfe2l2 was repressed in almost all mature neurons, but highly expressed in non-neuronal support cells, and this pattern was robust across multiple human CNS diseases. A subset of key Nrf2 target genes, like Slc7a11, also remained low in neurons. Thus, these data suggest that while most cells express Nfe2l2, with activity determined by ROS levels, neurons actively avoid Nrf2 activity by keeping Nfe2l2 expression low.

A potent phosphodiester Keap1-Nrf2 protein-protein interaction inhibitor as the efficient treatment of Alzheimer's disease

The Keap1-Nrf2 pathway has been established as a therapeutic target for Alzheimer's disease (AD). Directly inhibiting the protein-protein interaction (PPI) between Keap1 and Nrf2 has been reported as an effective strategy for treating AD. Our group has validated this in an AD mouse model for the first time using the inhibitor 1,4-diaminonaphthalene NXPZ-2 with high concentrations. In the present study, we reported a new phosphodiester containing diaminonaphthalene compound, POZL, designed to target the PPI interface using a structure-based design strategy to combat oxidative stress in AD pathogenesis. Our crystallographic verification confirms that POZL shows potent Keap1-Nrf2 inhibition. Remarkably, POZL showed its high in vivo anti-AD efficacy at a much lower dosage compared to NXPZ-2 in the transgenic APP/PS1 AD mouse model. POZL treatment in the transgenic mice could effectively ameliorate learning and memory dysfunction by promoting the Nrf2 nuclear translocation. As a result, the oxidative stress and AD biomarker expression such as BACE1 and hyperphosphorylation of Tau were significantly reduced, and the synaptic function was recovered. HE and Nissl staining confirmed that POZL improved brain tissue pathological changes by enhancing neuron quantity and function. Furthermore, it was confirmed that POZL could effectively reverse Aβ-caused synaptic damage by activating Nrf2 in primary cultured cortical neurons. Collectively, our findings demonstrated that the phosphodiester diaminonaphthalene Keap1-Nrf2 PPI inhibitor could be regarded as a promising preclinical candidate of AD.

The bridge between cell survival and cell death: reactive oxygen species-mediated cellular stress

As a requirement of aerobic metabolism, regulation of redox homeostasis is indispensable for the continuity of living homeostasis and life. Since the stability of the redox state is necessary for the maintenance of the biological functions of the cells, the balance between the pro-oxidants, especially ROS and the antioxidant capacity is kept in balance in the cells through antioxidant defense systems. The pleiotropic transcription factor, Nrf2, is the master regulator of the antioxidant defense system. Disruption of redox homeostasis leads to oxidative and reductive stress, bringing about multiple pathophysiological conditions. Oxidative stress characterized by high ROS levels causes oxidative damage to biomolecules and cell death, while reductive stress characterized by low ROS levels disrupt physiological cell functions. The fact that ROS, which were initially attributed as harmful products of aerobic metabolism, at the same time function as signal molecules at non-toxic levels and play a role in the adaptive response called mithormesis points out that ROS have a dose-dependent effect on cell fate determination. See also Figure 1(Fig. 1).

Limited Expression of Nrf2 in Neurons Across the Central Nervous System

Nrf2 is a broadly expressed transcription factor that regulates gene expression in response to reactive oxygen species (ROS) and oxidative stress. It is commonly referred to as a ubiquitous pathway, but this generalization overlooks work indicating that Nrf2 is essentially unexpressed in some neuronal populations. To explore whether this pattern extends throughout the central nervous system (CNS), we quantified Nrf2 expression and chromatin accessibility at the Nrf2 locus across multiple single cell datasets. In both the mouse and human CNS, Nrf2 was repressed in almost all mature neurons, but highly expressed in non-neuronal support cells, and this pattern was robust across multiple human CNS diseases. A subset of key Nrf2 target genes, like Slc7a11 , also remained low in neurons. Thus, these data suggest that while most cells express Nrf2, with activity determined by ROS levels, neurons actively avoid Nrf2 activity by keeping Nrf2 expression low.

Optimization and evaluation of pyridinyl vinyl sulfones as Nrf2 activator for the antioxidant and anti-inflammatory effects

Many studies have reported that chalcone-based compounds exhibit biological activities such as anticancer, antioxidant, anti-inflammatory and neuroprotective effects. Among the published chalcone derivatives, (E)-1-(3-methoxypyridin-2-yl)-3-(2-(trifluoromethyl)phenyl)prop-2-en-1-one (VEDA-1209), which is currently undergoing preclinical study, was selected as a starting compound for the development of new nuclear factor erythroid 2-related factor 2 (Nrf2) activators. Based on our previous knowledge, we attempted to redesign and synthesize VEDA-1209 derivatives by introducing the pyridine ring and sulfone moiety to ameliorate its Nrf2 efficacy and drug-like properties. Among the synthesized compounds, (E)-3-chloro-2-(2-((3-methoxypyridin-2-yl)sulfonyl)vinyl) pyridine (10e) was found to have approximately 16-folds higher Nrf2 activating effects than VEDA-1209 (10e: EC₅₀ = 37.9 nM vs VEDA-1209: EC₅₀ = 625 nM) in functional cell-based assay. In addition, 10e effectively improved drug-like properties such as CYP inhibition probability and metabolic stability. Finally, 10e demonstrated excellent antioxidant and anti-inflammatory effects in BV-2 microglial cells and significantly restored spatial memory deficits in lipopolysaccharide (LPS)-induced neuroinflammatory mouse models.

Matrine exerts its neuroprotective effects by modulating multiple neuronal pathways

Recent evidence suggests that misfolding, clumping, and accumulation of proteins in the brain may be common causes and pathogenic mechanism for several neurological illnesses. This causes neuronal structural deterioration and disruption of neural circuits. Research from various fields supports this idea, indicating that developing a single treatment for several severe conditions might be possible. Phytochemicals from medicinal plants play an essential part in maintaining the brain's chemical equilibrium by affecting the proximity of neurons. Matrine is a tetracyclo-quinolizidine alkaloid derived from the plant Sophora flavescens Aiton. Matrine has been shown to have a therapeutic effect on Multiple Sclerosis, Alzheimer's disease, and various other neurological disorders. Numerous studies have demonstrated that matrine protects neurons by altering multiple signalling pathways and crossing the blood-brain barrier. As a result, matrine may have therapeutic utility in the treatment of a variety of neurocomplications. This work aims to serve as a foundation for future clinical research by reviewing the current state of matrine as a neuroprotective agent and its potential therapeutic application in treating neurodegenerative and neuropsychiatric illnesses. Future research will answer many concerns and lead to fascinating discoveries that could impact other aspects of matrine.

Defects in Glutathione System in an Animal Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a progredient neurodegenerative disease characterized by a degeneration of the first and second motor neurons. Elevated levels of reactive oxygen species (ROS) and decreased levels of glutathione, which are important defense mechanisms against ROS, have been reported in the central nervous system (CNS) of ALS patients and animal models. The aim of this study was to determine the cause of decreased glutathione levels in the CNS of the ALS model wobbler mouse. We analyzed changes in glutathione metabolism in the spinal cord, hippocampus, cerebellum, liver, and blood samples of the ALS model, wobbler mouse, using qPCR, Western Blot, HPLC, and fluorometric assays. Here, we show for the first time a decreased expression of enzymes involved in glutathione synthesis in the cervical spinal cord of wobbler mice. We provide evidence for a deficient glutathione metabolism, which is not restricted to the nervous system, but can be seen in various tissues of the wobbler mouse. This deficient system is most likely the reason for an inefficient antioxidative system and, thus, for elevated ROS levels.