Beyond repression of Nrf2: An update on Keap1

Navigating the complexities of neuronal signaling and targets in neurological disorders: From pathology to therapeutics

Neurological disorders arising from structural and functional disruptions in the nervous system present major global health challenges. This review examines the intricacies of various cellular signaling pathways, including Nrf2/Keap1/HO-1, SIRT-1, JAK/STAT3/mTOR, and BACE-1/gamma-secretase/MAPT, which play pivotal roles in neuronal health and pathology. The Nrf2-Keap1 pathway, a key antioxidant response mechanism, mitigates oxidative stress, while SIRT-1 contributes to mitochondrial integrity and inflammation control. Dysregulation of these pathways has been identified in neurodegenerative and neuropsychiatric disorders, including Alzheimer's and Parkinson's diseases, characterized by inflammation, protein aggregation, and mitochondrial dysfunction. Additionally, the JAK/STAT3 signaling pathway emphasizes the connection between cytokine responses and neuroinflammation, further compounding disease progression. This review explores the crosstalk among these signaling networks, elucidating how their disruption leads to neuronal decline. It also addresses the dual roles of these pathways, presenting challenges in targeting them for therapeutic purposes. Despite the potential benefits of activating neuroprotective pathways, excessive stimulation may cause deleterious effects, including tumorigenesis. Future research should focus on designing multi-targeted therapies that enhance the effectiveness and safety of treatments, considering individual variabilities and the obstacles posed by the blood-brain barrier to drug delivery. Understanding these complex signaling interactions is crucial for developing innovative and effective neuroprotective strategies that could significantly improve the management of neurological disorders.

Molecular docking analyses on the chemical profile and antioxidant potential of Cakile maritima using GC-MS and HPLC

This study investigates the phytochemical composition, antioxidant activity, and potential biological applications of the methanol extract obtained from the above ground of Cakile maritima. Antioxidant analyses revealed DPPH IC₅₀ = 642.52 ± 29.68 mg/mL, FRAP radical scavenging activity = 1093.89 ± 17.68 mg/mL, and ferrous ion chelation activity IC₅₀ = 68.51 ± 1.53 mg/mL. The total phenolic and flavonoid contents were determined as 32.23 ± 1.97 mg GAE/g and 32.02 ± 5.64 mg QE/g, respectively. GC-MS analysis identified significant compounds such as 1H-imidazole, 4,5-dimethyl (9.94%) and dianhydromannitol (8.84%), highlighting their antioxidant and biomedical potential. Phenolic profiling was performed using HPLC, revealing dominant compounds such as gallic acid (407.93 mg/L) and pyrogallol (579.9 mg/L), while rutin (219.6 mg/L) emerged as the most abundant flavonoid. Molecular docking studies indicated that rutin is the strongest inhibitor of the target protein (ΔG = -9.1 kcal/mol, Ki = 0.00467 μM), supported by its strong binding interactions. Acute toxicity evaluations revealed low to moderate toxicity for most compounds, with dianhydromannitol showing higher toxicity (LD₅₀ = 8 mg/kg). Cytotoxicity predictions demonstrated significant antitumor potential of compounds such as pyridine, dianhydromannitol, and 1H-imidazole, 4,5-dimethyl against various cancer cell lines, including brain gliomas and colon adenocarcinomas. These findings highlight the rich chemical diversity and promising therapeutic potential of C. maritima extract.

Considerations for antibody-based detection of NRF2 in human cells

Based on the knockdown and overexpression experiments, it is accepted that in Tris-glycine SDS-PAGE human NRF2 migrates above 100 kDa, depending on the percentage of the gel. In 8 % Tris-glycine gel, monoclonal anti-NRF2 antibodies detect NRF2 signal as three bands migrating between 100 and 130 kDa. Here we used mass spectrometry to identify proteins immunoprecipitated by anti-NRF2 antibodies migrating in this range under steady state, upon NRF2 activator tert-BHQ and after translation inhibition with emetine. Our results show that three commercial monoclonal antibodies with epitopes in the center and in the C-terminus of NRF2 also bind calmegin, an ER-residing chaperone, that co-migrates with NRF2 in SDS-PAGE and gives stronger signal in western blot than NRF2. Calmegin has a much longer half life than NRF2 and resides in the cytoplasm, which differentiates it from NRF2. The most specific anti-NRF2 antibody in western blot, Cell Signaling Technology clone E5F1 is also specific in staining nuclear NRF2 in immunofluorescence. Other antibodies, that recognize calmegin in western blot, still can be specific for nuclear NRF2 in immunofluorescence, but require prior validation with NRF2 knockdown or knockout. These results appeal for caution and consideration when analyzing and interpreting results from antibody-based NRF2 detection.

Health position paper and redox perspectives - Bench to bedside transition for pharmacological regulation of NRF2 in noncommunicable diseases

Nuclear factor erythroid 2-related factor 2 (NRF2) is a redox-activated transcription factor regulating cellular defense against oxidative stress, thereby playing a pivotal role in maintaining cellular homeostasis. Its dysregulation is implicated in the progression of a wide array of human diseases, making NRF2 a compelling target for therapeutic interventions. However, challenges persist in drug discovery and safe targeting of NRF2, as unresolved questions remain especially regarding its context-specific role in diseases and off-target effects. This comprehensive review discusses the dualistic role of NRF2 in disease pathophysiology, covering its protective and/or destructive roles in autoimmune, respiratory, cardiovascular, and metabolic diseases, as well as diseases of the digestive system and cancer. Additionally, we also review the development of drugs that either activate or inhibit NRF2, discuss main barriers in translating NRF2-based therapies from bench to bedside, and consider the ways to monitor NRF2 activation in vivo.

Patenting perspective on Keap1 inhibitors (2019-2024)

INTRODUCTION

Kelch-like ECH-associated protein 1 (Keap1), an E3 ligase negatively regulating the nuclear factor erythroid 2-related factor 2 (Nrf2), has emerged as an auspicious drug target for treating ailments associated with oxidative stress and inflammation. Discovery of Keap1 inhibitors have attracted significant interest.

AREAS COVERED

This review covers patents on Keap1 inhibitors from 2019 to 2024, providing a comprehensive analysis of their structural characteristics, optimization strategies, pharmacological properties and clinical progress.

EXPERT OPINION

Extensive efforts have been devoted to enhance potency and drug-like properties of Keap1 inhibitors. Strategies such as ROS-cleavable prodrug design, bivalent inhibition and PROTACs are emerging. As the range of drug types and applications expands, Keap1 inhibitors are becoming a sagacious option for disease treating.

FGF21 Alleviates Hypoxic-Ischemic White Matter Injury in Neonatal Mice by Mediating Inflammation and Oxidative Stress Through PPAR-γ Signaling Pathway

White matter injury (WMI), the most common type of brain damage in infants born preterm, is characterized by failure in oligodendrocyte progenitor cell maturation and myelination, thereby contributing to long-term neurological impairments. Regrettably, effective therapies for promoting remyelination and improving function are currently lacking for this growing population affected by WMI. Recombinant human fibroblast growth factor (rhFGF) 21 modulated microglial activation and then ameliorated brain damage and improved neurological deficits in several central nervous system diseases. However, the effects of rhFGF21 treatment on WMI in preterm infants remain uncertain. In this study, we established an in vivo mouse model of cerebral hypoxia-ischemia (HI)-induced brain WMI and an in vitro model using oxygen-glucose deprivation (OGD)-treated HMC3 cells to investigate the neuroprotective effects of rhFGF21 against WMI and elucidated the potential mechanism. Our findings demonstrated that administration of rhFGF21 significantly ameliorated the retardation of oligodendrocyte differentiation, promoted myelination, and mitigated axonal deficits, synaptic loss, and GFAP scarring, thereby improving lifelong cognitive and neurobehavioral dysfunction associated with WMI. Moreover, rhFGF21 modulated microglial polarization, promoted a shift from the M1 to the M2 microglial phenotype, and suppressed microglial activation, thus ameliorating inflammatory response and oxidative stress. Additionally, rhFGF21 treatment significantly inhibited the HMGB1/NF-κB pathway linked to inflammation, and activated the NRF2 pathway associated with oxidative stress through the upregulation of PPAR-γ. Importantly, the beneficial effects of rhFGF21 on HI-induced WMI and microglial activation were dramatically inhibited by PPAR-γ antagonist and its siRNA. Our findings provide compelling evidence that rhFGF21 treatment mitigated the inflammatory response and oxidative stress through the modulation of microglial polarization via the PPAR-γ-mediated HMGB1/NF-κB pathway and the NRF2 pathway, respectively, contributes to neuroprotection and the amelioration of WMI in neonatal mice. Thus, rhFGF21 represents a promising therapeutic agent for the treatment of neonatal WMI.

Scutellarin Alleviates Bone Marrow Mesenchymal Stromal Cellular Senescence via the Ezh2-Nrf2 Signalling Axis in Diabetes-Induced Bone Loss

Currently, there is no specific treatment for diabetes-induced osteoporosis (DOP). Our study identified diabetes-induced cellular senescence, marked by elevated activity of senescence-associated β-galactosidase. Targeting senescent cells holds promise for osteoporosis treatment. We demonstrated that scutellarin (SCU) effectively mitigated bone loss in DOP mice, and co-treatment with SCU significantly reduced diabetes-induced senescence in LepR+MSCs. Furthermore, our research highlighted the role of Nrf2 in SCU's anti-senescence effects on bone. The deletion of Nrf2 impaired SCU's ability to alleviate DOP. Mechanistically, SCU enhances Ezh2 expression and increases H3K27me3 activity at the Keap1 promoter region, leading to Keap1 repression and enhanced Nrf2-ARE signalling. Additionally, SCU notably inhibited cellular senescence and diabetes-related osteoporosis, these effects were significantly reduced in Ezh2LepRcre conditional knockout models. These findings suggest that the Ezh2-Nrf2 signalling axis is crucial for mediating SCU's beneficial effects in this context. Overall, our discoveries provide insights into the mechanisms underlying DOP and propose a potential preventive strategy for this condition.

Muscle-specific Keap1 deletion enhances force production but does not prevent inactivity-induced muscle atrophy in mice

Immobilization-associated muscle atrophy and weakness appear to be driven in part by oxidative stress. Nuclear Factor Erythroid 2-Related Factor 2 (NRF2) is a critical redox rheostat that regulates oxidative stress responses, and its deletion is known to accelerate muscle atrophy and weakness during aging (sarcopenia) or denervation. Conversely, pharmacologic activation of NRF2 extends mouse lifespan and attenuates sarcopenia. Similarly, deletion of Kelch-like ECH-associated Protein 1 (Keap1), a negative regulator of NRF2, enhances exercise capacity. The purpose of this study was to determine whether muscle-specific Keap1 deletion is sufficient to prevent muscle atrophy and weakness in mice following 7 days of hindlimb unloading (HU). To test this hypothesis, control (Ctrl) and tamoxifen-inducible, muscle-specific Keap1 knockout (mKO) mice were subjected to either normal housing (Sham) or HU for 7 days. Activation of NRF2 in muscle was confirmed by increased mRNA of NRF2 targets thioredoxin 1 (Txn1) and NAD(P)H quinone dehydrogenase 1 (NQO1) in mKO mice. Keap1 deletion had an effect to increase force-generating capacity at baseline. However, muscle masses, cross-sectional area, and ex vivo force were not different between mKO and Ctrl HU mice. In addition, muscle 4-hydroxynonenal-modified proteins and protein carbonyls were unaffected by Keap1 deletion. These data suggest that NRF2 activation improves muscle force production during ambulatory conditions but is not sufficient to prevent muscle atrophy or weakness following 7 days of HU.

Green tea polyphenol epigallocatechin-3-gallate mediates an antioxidant response via Nrf2 pathway in heat-stressed poultry: A review

Heat stress is a critical challenge in the poultry industry. It arises when birds are exposed to elevated ambient temperatures beyond their thermoneutral zone, often exacerbated by high humidity and inadequate ventilation. This condition disrupts the birds' ability to maintain thermal homeostasis, leading to physiological and behavioral changes such as increased panting, reduced feed intake, and elevated water consumption. These responses aim to dissipate heat but often result in energy imbalances, oxidative stress, and impaired immune function. Green tea polyphenols (GTPs) mitigate heat stress in poultry birds by modulating oxidative stress pathways, primarily by scavenging reactive oxygen species (ROS) and enhancing antioxidant defense mechanisms. These pathways play a pivotal role in neutralizing ROS generated during oxidative stress, inflammation, and exposure to electrophilic compounds. This action helps restore cellular balance and enhances overall antioxidant defense mechanisms by converting harmful free radicals into less reactive molecules, such as water and oxygen. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) plays a significant character in the activation of the enzymatic antioxidants network. It translocates to the nucleus upon activation, binds to antioxidant response elements (AREs) in the promoter regions of target genes, and upregulates the expression of key antioxidant enzymes. Therefore, the regulation of Nrf2 is considered a critical molecular marker in mitigating the effects of heat stress, as its activation enhances the expression of antioxidant and detoxification enzymes, protecting against oxidative damage and inflammation induced by elevated temperatures. This exploratory review summarizes the antioxidant mechanisms and anti-oxidative stress effects of GTPs in mitigating heat stress in poultry. It highlights the cytoprotective molecular basis of epigallocatechin-3-gallate (EGCG), particularly its role in modulating Nrf2-mediated cellular pathways, which enhance antioxidant defense systems and protect against oxidative damage.

[Dexmedetomidine attenuates heat stress-induced oncosis in human skeletal muscle cells by activating the Nrf2/Ho-1 pathway]

OBJECTIVES

To investigate the protective effects of dexmedetomidine (DEX) against heat stress (HS)-induced oncosis in human skeletal muscle cells (HSKMCs) and its underlying mechanisms.

METHODS

A HSKMC model of HS-induced oncosis were established by 43 ℃ water bath for 4 h, and the effects of treatments with 30 μmol/L DEX, ML385 (a Nrf2 inhibitor) +DEX, si-Nrf2+HS, and si-Nrf2+DEX prior to modeling on cell viability was assessed using CCK-8 assay. Oncosis characteristics were evaluated using transmission electron microscopy and Annexin V-FITC/PI flow cytometry. The oxidative stress markers (GSH, GSH-Px, MDA, SOD and ROS), mitochondrial membrane potential, energy metabolism, and inflammatory cytokines (TNF-α, IL-6 and IL-1β) in the cells were quantified using standard kits, and the expressions of porimin, caspase-3 and Nrf2 pathway proteins were analyzed using Western blotting and qRT-PCR.

RESULTS

HS induced typical oncotic features in HSKMCs including organelle swelling and cytoplasmic vacuolization. DEX pretreatment significantly attenuated these changes, reduced Annexin V+/PI+ cell ratio and cellular porimin expression, and lowered the levels of ROS and MDA while restoring GSH and SOD levels. DEX pretreatment also significantly increased the mitochondrial membrane potential and ATP level, upregulated the expressions of Nrf2, p-Nrf2, HO-1 and NQO1, and suppressed the expressions of TNF-α, IL-6 and IL-1β. The protective effects of DEX were obviously attenuated by interventions with ML385 or si-Nrf2.

CONCLUSIONS

DEX mitigates HS-induced HSKMC oncosis by activating the Nrf2/HO-1 pathway to relieve oxidative stress, mitochondrial dysfunction, and inflammatory responses.

The dual nature of KLHL proteins: From cellular regulators to disease drivers

The Kelch-like (KLHL) protein family, characterized by its conserved BTB, BACK, and Kelch domains, serves as substrate adaptors for Cullin 3-RING ligases (CRL3), facilitating the ubiquitination and degradation of specific target proteins. Through this mechanism, KLHL proteins regulate numerous physiological processes, including cytoskeletal organization, oxidative stress response, and cell cycle progression. Dysregulation of KLHL proteins-via mutations or abnormal expression-has been implicated in various pathological conditions, including neurodegenerative disorders, cancer, cardiovascular diseases, and hereditary syndromes. This review provides a comprehensive overview of the physiological and pathological roles of KLHL proteins, emphasizing their specific substrates and mechanisms of action. By integrating structural and mechanistic insights with translational research, this review underscores the potential of KLHL proteins as promising therapeutic targets, offering new opportunities to combat a wide spectrum of complex diseases.

The Regulation of γ-Aminobutyric Acid on Antioxidative Defense Response of Pacific Oyster upon High-Temperature Stress

Recent studies have found that high temperatures cause oxidative stress and even mass mortality in Pacific oysters (Crassostrea gigas). The role of γ-aminobutyric acid (GABA) in improving antioxidative defense in aquatic animals is increasingly of interest. In the present study, the oxidative stress of Pacific oysters to high-temperature stress was examined, and the regulation of GABA on the antioxidative defense was further investigated. Following 6 h of exposure to 28 °C seawater, a significant increase in the mRNA expression levels of nuclear factor-E2-related factor 2 (Nrf2), superoxide dismutase (SOD), and catalase (CAT), as well as the activities of SOD and CAT, was observed in the gill, compared to those at 0 h. An increase of glutamate decarboxylase (GAD), GABA receptor (GABAAR-α and GABABR-B) mRNA levels, and GABA contents were also detected after 28 °C exposure compared to those at 0 h. Furthermore, the activities and mRNA expression levels of SOD and CAT were significantly upregulated after GABA treatment, while decreased after either GAD inhibitor or GABA receptor inhibitor treatment under high-temperature stress. Meanwhile, the enhanced effects of GABA on antioxidant enzyme activities were reduced when Nrf2 was inhibited by ML385, accompanied by an increase in MDA content. After high-temperature stress, compared with the GABA treatment group, the activities and mRNA expression levels of SOD and CAT were significantly upregulated by GSK-3β inhibitor treatment. Meanwhile, the elevation of antioxidant enzyme activities by GABA was attenuated by the AKT inhibitor treatment. Collectively, GABA first activated GABA receptors under high-temperature stress and then increased the activities of SOD and CAT and reduced MDA content by AKT/GSK-3β and Nrf2 pathways to protect the oysters against oxidative damage upon stress. The present results offer new insights for understanding the regulation mechanisms of antioxidative defense by the neuroendocrine system in molluscs.

KEAP1-NRF2 Interaction in Cancer: Competitive Interactors and Their Role in Carcinogenesis

An American Cancer Society report estimates the emergence of around 2 million new cancer cases in the US in 2024 [...].

Brassinin from Brassica campestris L. inhibits colorectal cancer by inducing p62/NRF2/GPX4-regulated ferroptosis

BACKGROUND

Indole phytoalexins, plant-derived compounds present in cruciferous vegetables, have demonstrated anticancer properties. Brassinin (BSN), derived from Brassica campestris L. var. campestris, is known for its potent antitumor effects on various cancers. However, the role of ferroptosis in regulating the antitumor effects of BSN has not been fully elucidated.

METHODS

The components of B. campestris L. against colorectal cancer (CRC) were analyzed by network pharmacology. CCK-8 assay and colony formation assay detected cell viability induced by BSN. Molecular docking verified the binding of BSN to the target protein. Western blot and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay revealed whether BSN can inactivate the NRF2 signaling and inhibit the expression of p62 and HO-1. The RKO-xenograft tumor models were established and then were treated by 75 or 150 mg/kg BSN to verify the antitumor efficacy and side effects of BSN.

RESULTS

Network pharmacology suggested that BSN is the most important component of B. campestris L. against CRC. BSN inhibits CRC cell viability in a dose- and time-dependent manner. Furthermore, this inhibitory effect is associated with the induction of ferroptosis, as BSN suppresses the cell viability of CRC by inducing GPX4-regulated ferroptosis. BSN may bind to NRF2 protein to inactivate the NRF2 signaling, inhibiting the expression of p62 and HO-1. Importantly, a low dose or a high dose of BSN significantly reduced the tumor growth in vivo.

CONCLUSIONS

Our findings reveal that BSN blocks CRC growth by inducing p62/NRF2/GPX4-regulated ferroptosis, which may be a novel lead compound for tumor treatment.

Deciphering Oxidative Stress in Cardiovascular Disease Progression: A Blueprint for Mechanistic Understanding and Therapeutic Innovation

Oxidative stress plays a pivotal role in the pathogenesis and progression of cardiovascular diseases (CVDs). This review focuses on the signaling pathways of oxidative stress during the development of CVDs, delving into the molecular regulatory networks underlying oxidative stress in various disease stages, particularly apoptosis, inflammation, fibrosis, and metabolic imbalance. By examining the dual roles of oxidative stress and the influences of sex differences on oxidative stress levels and cardiovascular disease susceptibility, this study offers a comprehensive understanding of the pathogenesis of cardiovascular diseases. The study integrates key findings from current research in three comprehensive ways. First, it outlines the major CVDs associated with oxidative stress and their respective signaling pathways, emphasizing oxidative stress's central role in cardiovascular pathology. Second, it summarizes the cardiovascular protective effects, mechanisms of action, and animal models of various antioxidants, offering insights into future drug development. Third, it discusses the applications, advantages, limitations, and potential molecular targets of gene therapy in CVDs, providing a foundation for novel therapeutic strategies. These tables underscore the systematic and integrative nature of this study while offering a theoretical basis for precision treatment for CVDs. A major contribution of this study is the systematic review of the differential effects of oxidative stress across different stages of CVDs, in addition to the proposal of innovative, multi-level intervention strategies, which open new avenues for precision treatment of the cardiovascular system.

Adverse Effects of Nrf2 in Different Organs and the Related Diseases

Significance: Under normal physiological conditions, Nrf2 undergoes ubiquitination and subsequent proteasome degradation to maintain its basal activity. Oxidative stress can trigger Nrf2 activation, prompting its translocation to the nucleus where it functions as a transcription factor, activating various antioxidant pathways, and conferring antioxidant properties. Recent Advances: While extensive research has shown Nrf2's protective role in various diseases, emerging evidence suggests that Nrf2 activation can also produce harmful effects. Critical Issues: This review examines the pathological contexts in which Nrf2 assumes different roles, emphasizing the mechanisms and conditions that result in adverse outcomes. Future Directions: Persistent Nrf2 activation may have deleterious consequences, necessitating further investigation into the specific conditions and mechanisms through which Nrf2 exerts its harmful effects. Antioxid. Redox Signal. 00, 000-000.

CRL3Keap1 E3 ligase facilitates ubiquitin-mediated degradation of oncogenic SRX to suppress colorectal cancer progression

The antioxidant protein sulfiredoxin-1 (SRX) is an oncogenic factor that promotes tumor progression, but the regulatory mechanism underlying SRX degradation remains to be understood. Herein, we report that Keap1, the substrate-specific adapter of CRL3 complex, specifically binds and promotes the ubiquitin-mediated degradation of SRX at residue K61. Keap1 knockdown accumulates SRX, which in turn facilitates colorectal cancer (CRC) metastasis by activating the activator protein-1/matrix metalloproteinase 9 (AP-1/MMP9) pathway. CRC-associated Keap1 mutants within the BACK domain lose the capability to ubiquitinate SRX and instead promote CRC metastasis. Moreover, inactivation of Keap1 facilitates CRC tumorigenesis and metastasis in mouse models of tumor xenograft due to SRX accumulation. Clinical sample analysis reveals that Keap1 is downregulated while SRX is overexpressed in CRC, which correlates with poor prognosis. Our findings elucidate a mechanism by which CRL3Keap1 ubiquitin ligase degrades SRX to suppress CRC progression, indicating that the Keap1-SRX axis will guide the targeted therapy towards CRC.

Sex differences in the BTBR idiopathic mouse model of autism spectrum disorders: Behavioural and redox-related hippocampal alterations

Autism spectrum disorders (ASD) are highly heterogeneous neurodevelopmental diseases. Epidemiological data report that males have been diagnosed with autism more frequently than females. However, recent studies hypothesize that females' low incidence might be underestimated due to standard clinical measures of ASD behavioural symptoms, mostly derived from males. Indeed, up to now, ASD mouse models focused mainly on males, considering the prevalence of the diagnosis in that sex. Regarding ASD aetiopathogenesis, it has been recently reported that oxidative stress might be implicated in its onset and development, suggesting an association with ASD typical repetitive behaviours that still need to be disentangled. Here, we investigated possible behavioural and molecular sex-related differences by using the BTBR mouse model of idiopathic ASD. To this aim, animals were exposed to behavioural tests related to different ASD core symptoms and comorbidities, i.e. stereotyped repertoire, social dysfunctions, hyperlocomotion and risk-taking behaviours. Moreover, we analyzed hippocampal levels of pro-oxidant and anti-oxidant enzymes, together with biomarkers of oxidative stress and lipid peroxidation. Our results showed that BTBR females did not display the same patterns for repetitive behaviours as the male counterpart. From a biomolecular point of view, we found an increase in oxidative stress and pro-oxidant enzymes, accompanied by deficient enzymatic anti-oxidant response, only in BTBR males compared to C57BL/6 male mice, while no differences were retrieved in females. Overall, our study suggests that in females there is an urgent need to depict the distinct ASD symptomatology, accompanied by the identification of sex-specific pharmacological targets.

Unveiling Smyd-2's Role in Cytoplasmic Nrf-2 Sequestration and Ferroptosis Induction in Hippocampal Neurons After Cerebral Ischemia/Reperfusion

SET and MYND Domain-Containing 2 (Smyd-2), a specific protein lysine methyltransferase (PKMT), influences both histones and non-histones. Its role in cerebral ischemia/reperfusion (CIR), particularly in ferroptosis-a regulated form of cell death driven by lipid peroxidation-remains poorly understood. This study identifies the expression of Smyd-2 in the brain and investigates its relationship with neuronal programmed cell death (PCD). We specifically investigated how Smyd-2 regulates ferroptosis in CIR through its interaction with the Nuclear Factor Erythroid-2-related Factor-2 (Nrf-2)/Kelch-like ECH-associated protein (Keap-1) pathway. Smyd-2 knockout protects HT-22 cells from Erastin-induced ferroptosis but not TNF-α + Smac-mimetic-induced apoptosis/necroptosis. This neuroprotective effect of Smyd-2 knockout in HT-22 cells after Oxygen-Glucose Deprivation/Reperfusion (OGD/R) was reversed by Erastin. Smyd-2 knockout in HT-22 cells shows neuroprotection primarily via the Nuclear Factor Erythroid-2-related Factor-2 (Nrf-2)/Kelch-like ECH-associated protein (Keap-1) pathway, despite the concurrent upregulation of Smyd-2 and Nrf-2 observed in both the middle cerebral artery occlusion (MCAO) and OGD/R models. Interestingly, vivo experiments demonstrated that Smyd-2 knockout significantly reduced ferroptosis and lipid peroxidation in hippocampal neurons following CIR. Moreover, the Nrf-2 inhibitor ML-385 abolished the neuroprotective effects of Smyd-2 knockout, confirming the pivotal role of Nrf-2 in ferroptosis regulation. Cycloheximide (CHX) fails to reduce Nrf-2 expression in Smyd-2 knockout HT-22 cells. Smyd-2 knockout suppresses Nrf-2 lysine methylation, thereby promoting the Nrf-2/Keap-1 pathway without affecting the PKC-δ/Nrf-2 pathway. Conversely, Smyd-2 overexpression disrupts Nrf-2 nuclear translocation, exacerbating ferroptosis and oxidative stress, highlighting its dual regulatory role. This study underscores Smyd-2's potential for ischemic stroke treatment by disrupting the Smyd-2/Nrf-2-driven antioxidant capacity, leading to hippocampal neuronal ferroptosis. By clarifying the intricate interplay between ferroptosis and oxidative stress via the Nrf-2/Keap-1 pathway, our findings provide new insights into the molecular mechanisms of CIR and identify Smyd-2 as a promising therapeutic target.

Antioxidant 1,2,3,4,6-Penta-O-galloyl-β-D-glucose Alleviating Apoptosis and Promoting Bone Formation Is Associated with Estrogen Receptors

1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG) is the main phenolic active ingredient in Paeoniae Radix Alba, which is commonly used for the treatment of osteoporosis (OP). PGG is a potent natural antioxidant, and its effects on OP remain unknown. This study aimed to investigate the effects of PGG on promoting bone formation and explore its estrogen receptor (ER)-related mechanisms. A hydrogen peroxide-induced osteoblast apoptosis model was established in MC3T3-E1 cells. The effects of PGG were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, alkaline phosphatase (ALP) staining, RT-qPCR, and Western blot methods. Furthermore, a prednisolone-induced zebrafish OP model was employed to study the effects in vivo. ER inhibitors and molecular docking methods were used further to investigate the interactions between PGG and ERs. The results showed that PGG significantly enhanced cell viability and decreased cell apoptosis by restoring mitochondrial function, attenuating reactive oxygen species levels, decreasing the mitochondrial membrane potential, and enhancing ATP production. PGG enhanced ALP expression and activity and elevated osteogenic differentiation. PGG also promoted bone formation in the zebrafish model, and these effects were reversed by ICI182780. These results provide evidence that the effects of PGG in alleviating apoptosis and promoting bone formation may depend on ERs. As such, PGG is considered a valuable candidate for treating OP.

Tanshinone IIA Loaded Inhaled Polymer Nanoparticles Alleviate Established Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal respiratory disease characterized by chronic, progressive scarring of the lung parenchyma, leading to an irreversible decline in lung function. Apart from supportive care, there is currently no specific treatment available to reverse the disease. Based on the fact that tanshinone IIA (TAN) had an effect on protecting against TGF-β1-induced fibrosis through the inhibition of Smad and non-Smad signal pathways to avoid myofibroblasts activation, this study reported the development of the inhalable tanshinone IIA-loaded chitosan-oligosaccharides-coated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (CPN@TAN) for enhancing the pulmonary delivery of tanshinone IIA to treat pulmonary fibrosis. The CPN@TAN with a size of 206.5 nm exhibited excellent in vitro aerosol delivery characteristics, featuring a mass median aerodynamic diameter (MMAD) of 3.967 ± 0.025 μm and a fine particle fraction (FPF) of 70.516 ± 0.929%. Moreover, the nanoparticles showed good stability during atomization and enhanced the mucosal penetration capabilities. The results of confocal spectroscopy confirmed the potential of the nanoparticles as carriers that facilitated the uptake of drugs by NIH3T3, A549, and MH-S cells. Additionally, the nanoparticles demonstrated good in vitro biocompatibility. In a mouse model of bleomycin-induced pulmonary fibrosis, noninvasive inhalation of aerosol CPN@TAN greatly suppressed collagen formation and facilitated re-epithelialization of the destroyed alveolar epithelium without causing systemic toxicity compared with intravenous administration. Consequently, our noninvasive inhalation drug delivery technology based on polymers may represent a promising paradigm and open the door to overcoming the difficulties associated with managing pulmonary fibrosis.

Interplay of Cellular Nrf2/NF-κB Signalling after Plasma Stimulation of Malignant vs. Non-Malignant Dermal Cells

Skin cancer is one of the most common malignancies worldwide. Cold atmospheric pressure Plasma (CAP) is increasingly successful in skin cancer therapy, but further research is needed to understand its selective effects on cancer cells at the molecular level. In this study, A431 (squamous cell carcinoma) and HaCaT (non-malignant) cells cultured under identical conditions revealed similar ROS levels but significantly higher antioxidant levels in unstimulated A431 cells, indicating a higher metabolic turnover typical of tumour cells. HaCaT cells, in contrast, showed increased antioxidant levels upon CAP stimulation, reflecting a robust redox adaptation. Specifically, proteins involved in antioxidant pathways, including NF-κB, IκBα, Nrf2, Keap1, IKK, and pIKK, were quantified, and their translocation level upon stimulation was evaluated. CAP treatment significantly elevated Nrf2 nuclear translocation in non-malignant HaCaT cells, indicating a strong protection against oxidative stress, while selectively inducing NF-κB activation in A431 cells, potentially leading to apoptosis. The expression of pro-inflammatory genes like IL-1B, IL-6, and CXCL8 was downregulated in A431 cells upon CAP treatment. Notably, CAP enhanced the expression of antioxidant response genes HMOX1 and GPX1 in non-malignant cells. The differential response between HaCaT and A431 cells underscores the varied antioxidative capacities, contributing to their distinct molecular responses to CAP-induced oxidative stress.

Isoliquiritigenin as a modulator of the Nrf2 signaling pathway: potential therapeutic implications

Nuclear factor erythroid-2-related factor 2 (Nrf2), a transcription factor responsible for cytoprotection, plays a crucial role in regulating the expression of numerous antioxidant genes, thereby reducing reactive oxygen species (ROS) levels and safeguarding cells against oxidative stress. Extensive research has demonstrated the involvement of Nrf2 in various diseases, prompting the exploration of Nrf2 activation as a potential therapeutic approach for a variety of diseases. Consequently, there has been a surge of interest in investigating the Nrf2 signaling pathway and developing compounds that can modulate its activity. Isoliquiritigenin (ISL) (PubChem CID:638278) exhibits a diverse range of pharmacological activities, including antioxidant, anticancer, and anti-tumor properties. Notably, its robust antioxidant activity has garnered significant attention. Furthermore, ISL has been found to possess therapeutic effects on various diseases, such as diabetes, cardiovascular diseases, kidney diseases, and cancer, through the activation of the Nrf2 pathway. This review aims to evaluate the potential of ISL in modulating the Nrf2 signaling pathway and summarize the role of ISL in diverse diseases prevention and treatment through modulating the Nrf2 signaling pathway.

The extract of buds of Chrysanthemum morifolium ramat alleviated UVB-induced skin photoaging by regulating MAPK and Nrf2/ARE pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Chrysanthemum morifolium Ramat. is a commonly used Chinese herb and food homologous plant with traditional effects such as anti-inflammatory, antifebrile, antibacterial and antiviral.

AIM OF STUDY

Photoaging is one of the main causes of accelerated skin aging. Chrysanthemum morifolium Ramat. has reported to alleviate photodamage. In this study, we investigated the protective effect of the extract of buds of Chrysanthemum morifolium Ramat. (CE) on UVB-induced photoaging and further mechanism.

MATERIALS AND METHODS

The extract of buds of chrysanthemum was analyzed by HPLC-Q-TOF-MS/MS. Antioxidant activity was assessed by DPPH and ABTS assay. Cell viability examined by cell counting kit-8 assay. The ROS level was detected by fluorescent probe DCFH-DA. Protein expression evaluated by Western blotting. The skin tissue investigated by immunohistochemistry.

RESULTS

CE significantly reversed the decrease of cell viability that induced by UVB in HaCaT and HFF-1 cells. Further analysis showed that CE alleviated photoaging by inhibiting the expression of mitogen-activated protein kinase (MAPK) and activating the NF-E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway to promote the expression of antioxidant enzymes. Moreover, CE effectively improved the reduced skin hydration, disordered collagen and thickening epidermis caused by UVB in mice.

CONCLUSIONS

All results demonstrated that CE had therapeutic effect on UVB-induced photoaging and provided theoretical basis for its further developing as a natural functional product with anti-photoaging effect.

The Role of Ferroptosis in Amyotrophic Lateral Sclerosis Treatment

Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disease with a challenging treatment landscape, due to its complex pathogenesis and limited availability of clinical drugs. Ferroptosis, an iron-dependent form of programmed cell death (PCD), stands distinct from apoptosis, necrosis, autophagy, and other cell death mechanisms. Recent studies have increasingly highlighted the role of iron deposition, reactive oxygen species (ROS) accumulation, oxidative stress, as well as systemic Xc- and glutamate accumulation in the antioxidant system in the pathogenesis of amyotrophic lateral sclerosis. Therefore, targeting ferroptosis emerges as a promising strategy for amyotrophic lateral sclerosis treatment. This review introduces the regulatory mechanism of ferroptosis, the relationship between amyotrophic lateral sclerosis and ferroptosis, and the drugs used in the clinic, then discusses the current status of amyotrophic lateral sclerosis treatment, hoping to provide new directions and targets for its treatment.

Nrf2-mediated ferroptosis inhibition: a novel approach for managing inflammatory diseases

Inflammatory diseases, including psoriasis, atherosclerosis, rheumatoid arthritis, and ulcerative colitis, are characterized by persistent inflammation. Moreover, the existing treatments for inflammatory diseases only provide temporary relief by controlling symptoms, and treatments of unstable and expensive. Therefore, new therapeutic solutions are urgently needed to address the underlying causes or symptoms of inflammatory diseases. Inflammation frequently coincides with a high level of (reactive oxygen species) ROS activation, serving as a fundamental element in numerous physiological and pathological phenotypes that can result in serious harm to the organism. Given its pivotal role in inflammation, oxidative stress, and ferroptosis, ROS represents a focal node for investigating the (nuclear factor E2-related factor 2) Nrf2 pathway and ferroptosis, both of which are intricately linked to ROS. Ferroptosis is mainly triggered by oxidative stress and involves iron-dependent lipid peroxidation. The transcription factor Nrf2 targets several genes within the ferroptosis pathway. Recent studies have shown that Nrf2 plays a significant role in three key ferroptosis-related routes, including the synthesis and metabolism of glutathione/glutathione peroxidase 4, iron metabolism, and lipid processes. As a result, ferroptosis-related treatments for inflammatory diseases have attracted much attention. Moreover, drugs targeting Nrf2 can be used to manage inflammatory conditions. This review aimed to assess ferroptosis regulation mechanism and the role of Nrf2 in ferroptosis inhibition. Therefore, this review article may provide the basis for more research regarding the treatment of inflammatory diseases through Nrf2-inhibited ferroptosis.

The role of Keap1-Nrf2 signaling pathway in the treatment of respiratory diseases and the research progress on targeted drugs

Lungs are exposed to external oxidants from the environment as in harmful particles and smog, causing oxidative stress in the lungs and consequently respiratory ailment. The NF-E2-related factor 2 (Nrf2) is the one with transcriptional regulatory function, while its related protein Kelch-like ECH-associated protein 1 (Keap1) inhibits Nrf2 activity. Together, they form the Keap1-Nrf2 pathway, which regulates the body's defense against oxidative stress. This pathway has been shown to maintain cellular homeostasis during oxidative stressing, inflammation, oncogenesis, and apoptosis by coordinating the expression of cytoprotective genes and making it a potential therapeutic target for respiratory diseases. This paper summarizes this point in detail in Chapter 2. In addition, this article summarizes the current drug development and clinical research progress related to the Keap1-Nrf2 signaling pathway, with a focus on the potential of Nrf2 agonists in treating respiratory diseases. Overall, the article reviews the regulatory mechanisms of the Keap1-Nrf2 signaling pathway in respiratory diseases and the progress of targeted drug research, aiming to provide new insights for treatment.

Potential of NRF2 Inhibitors-Retinoic Acid, K67, and ML-385-In Overcoming Doxorubicin Resistance in Promyelocytic Leukemia Cells

Drug resistance is one of the major obstacles to the clinical use of doxorubicin, an extensively used chemotherapeutic drug to treat various cancers, including leukemia. Inhibition of the nuclear factor erythroid 2-related factor 2 (NRF2) seems a promising strategy to reverse chemoresistance in cancer cells. NRF2 is a transcription factor that regulates both antioxidant defense and drug detoxification mechanisms. In this study, we investigated the potential of three inhibitors of NRF2-K67, retinoic acid and ML-385-to overcome doxorubicin resistance in promyelocytic leukemia HL-60 cells. For this purpose, low-dose doxorubicin was used to establish doxorubicin-resistant HL-60/DR cells. The expression of NRF2 and its main repressor, Kelch-like ECH-associated protein 1 (KEAP1), at mRNA and protein levels was examined. HL-60/DR cells overexpressed NRF2 at mRNA and protein levels and down-regulated KEAP1 protein compared to drug-sensitive HL-60 cells. The effects of NRF2 inhibitors on doxorubicin-resistant HL-60/DR cell viability, apoptosis, and intracellular reactive oxygen species (ROS) levels were analyzed. We observed that NRF2 inhibitors significantly sensitized doxorubicin-resistant HL-60/DR cells to doxorubicin, which was associated with increased intracellular ROS levels and the expression of CAS-9, suggesting the participation of the mitochondrial-dependent apoptosis pathway. Furthermore, ML-385 inhibitor was used to study the expression of NRF2-KEAP1 pathway genes. NRF2 gene and protein expression remained unchanged; however, we noted the down-regulation of KEAP1 protein upon ML-385 treatment. Additionally, the expression of NRF2-regulated antioxidant and detoxification genes including SOD2, HMOX2, and GSS was maintained upon ML-385 treatment. In conclusion, our results demonstrated that all the studied inhibitors, namely K67, retinoic acid, and ML-385, increased the efficacy of doxorubicin in doxorubicin-resistant HL-60/DR cells, and suggested a potential strategy of combination therapy using NRF2 inhibitors and doxorubicin in overcoming doxorubicin resistance in leukemia.

Genome-Wide CRISPR Screen Identifies KEAP1 Perturbation as a Vulnerability of ARID1A-Deficient Cells

ARID1A is the core DNA-binding subunit of the BAF chromatin remodeling complex and is mutated in about 8% of all cancers. The frequency of ARID1A loss varies between cancer subtypes, with clear cell ovarian carcinoma (CCOC) presenting the highest incidence at > 50% of cases. Despite a growing understanding of the consequences of ARID1A loss in cancer, there remains limited targeted therapeutic options for ARID1A-deficient cancers. Using a genome-wide CRISPR screening approach, we identify KEAP1 as a genetic dependency of ARID1A in CCOC. Depletion or chemical perturbation of KEAP1 results in selective growth inhibition of ARID1A-KO cell lines and edited primary endometrial epithelial cells. While we confirm that KEAP1-NRF2 signalling is dysregulated in ARID1A-KO cells, we suggest that this synthetic lethality is not due to aberrant NRF2 signalling. Rather, we find that KEAP1 perturbation exacerbates genome instability phenotypes associated with ARID1A deficiency. Together, our findings identify a potentially novel synthetic lethal interaction of ARID1A-deficient cells.

Optimization of a Modular Nanotransporter Design for Targeted Intracellular Delivery of Photosensitizer

Modular nanotransporters (MNTs) are drug delivery systems for targeted cancer treatment. As MNTs are composed of several modules, they offer the advantage of high specificity and biocompatibility in delivering drugs to the target compartment of cancer cells. The large carrier module brings together functioning MNT modules and serves as a platform for drug attachment. The development of smaller-sized MNTs via truncation of the carrier module appears advantageous in facilitating tissue penetration. In this study, two new MNTs with a truncated carrier module containing either an N-terminal (MNTN) or a C-terminal (MNTC) part were developed by genetic engineering. Both new MNTs demonstrated a high affinity for target receptors, as revealed by fluorescent-labeled ligand-competitive binding. The liposome leakage assay proved the endosomolytic activity of MNTs. Binding to the importin heterodimer of each truncated MNT was revealed by a thermophoresis assay, while only MNTN possessed binding to Keap1. Finally, the photodynamic efficacy of the photosensitizer attached to MNTN was significantly higher than when attached to either MNTC or the original MNTs. Thus, this work reveals that MNT's carrier module can be truncated without losing MNT functionality, favoring the N-terminal part of the carrier module due to its ability to bind Keap1.

Vorinostat Treatment of Gastric Cancer Cells Leads to ROS-Induced Cell Inhibition and a Complex Pattern of Molecular Alterations in Nrf2-Dependent Genes

Histone deacetylase inhibitors (HDACi) show high antineoplastic potential in preclinical studies in various solid tumors, including gastric carcinoma; however, their use in clinical studies has not yet yielded convincing efficacies. Thus, further studies on cellular/molecular effects of HDACi are needed, for improving clinical efficacy and identifying suitable combination partners. Here, we investigated the role of oxidative stress in gastric cancer cells upon treatment with HDACi. A particular focus was laid on the role of the Nrf2 pathway, which can mediate resistance to cell-inhibitory effects of reactive oxidative species (ROS). Using fluorescence-based ROS sensors, oxidative stress was measured in human gastric cancer cell lines. Activation of the Nrf2 pathway was monitored in luciferase reporter assays as well as by mRNA and proteomic expression analyses of Nrf2 regulators and Nrf2-induced genes. Furthermore, the effects of ROS scavenger N-acetyl-L-cysteine (NAC) and Nrf2-knockdown on HDACi-dependent antiproliferative effects were investigated in colorimetric formazan-based and clonogenic survival assays. HDACi treatment led to increased oxidative stress levels and consequently, treatment with NAC reduced cytotoxicity of HDACi. In addition, vorinostat treatment stimulated expression of a luciferase reporter under the control of an antioxidative response element, indicating activation of the Nrf2 system. This Nrf2 activation was only partially reversible by treatment with NAC, suggesting ROS independent pathways to contribute to HDACi-promoted Nrf2 activation. In line with its cytoprotective role, Nrf2 knockdown led to a sensitization against HDACi. Accordingly, the expression of antioxidant and detoxifying Nrf2 target genes was upregulated upon HDACi treatment. In conclusion, oxidative stress induction upon HDAC inhibition contributes to the antitumor effects of HDAC inhibitors, and activation of Nrf2 represents a potentially important adaptive response of gastric cancer cells in this context.

Nrf2-Mediated Antioxidant Response and Drug Efflux Transporters Upregulation as Possible Mechanisms of Resistance in Photodynamic Therapy of Cancers

Photodynamic therapy (PDT) is a groundbreaking approach involving the induction of cytotoxic reactive oxygen species (ROS) within tumors through visible light activation of photosensitizers (PS) in the presence of molecular oxygen. This innovative therapy has demonstrated success in treating various cancers. While PDT proves highly effective in most solid tumors, there are indications that certain cancers exhibit resistance, and some initially responsive cancers may develop intrinsic or acquired resistance to PDT. The molecular mechanisms underlying this resistance are not fully understood. Recent evidence suggests that, akin to other traditional cancer treatments, the activation of survival pathways, such as the KEAP1/Nrf2 signaling pathway, is emerging as an important mechanism of post-PDT resistance in many cancers. This article explores the dual role of Nrf2, highlighting evidence linking aberrant Nrf2 expression to treatment resistance across a range of cancers. Additionally, it delves into the specific role of Nrf2 in the context of photodynamic therapy for cancers, emphasizing evidence that suggests Nrf2-mediated upregulation of antioxidant responses and induction of drug efflux transporters are potential mechanisms of resistance to PDT in diverse cancer types. Therefore, understanding the specific role(s) of Nrf2 in PDT resistance may pave the way for the development of more effective cancer treatments using PDT.

Transcriptional Dynamics of NRF2 Overexpression and KEAP1-NRF2 Inhibitors in Human Cell Line and Primary Lung Cells

Oxidative stress in the human lung is caused by both internal (e.g., inflammation) and external stressors (smoking, pollution, and infection) to drive pathology in a number of lung diseases. Cellular damage caused by oxidative damage is reversed by several pathways, one of which is the antioxidant response. This response is regulated by the transcriptional factor NRF2, which has the ability to regulate the transcription of more than 250 genes. In disease, this balance is overwhelmed, and the cells are unable to return to homeostasis. Several pharmacological approaches aim to improve the antioxidant capacity by inhibiting the interaction of NRF2 with its key cytosolic inhibitor, KEAP1. Here, we evaluate an alternative approach by overexpressing NRF2 from chemically modified RNAs (cmRNAs). Our results demonstrate successful expression of functional NRF2 protein in human cell lines and primary cells. We establish a kinetic transcriptomic profile to compare antioxidant response gene expression after treatment of primary human bronchial epithelial cells with either KEAP1 inhibitors or cmRNAs. The key gene signature is then applied to primary human lung fibroblasts and alveolar macrophages to uncover transcriptional preferences in each cell system. This study provides a foundation for the understanding of NRF2 dynamics in the human lung and provides initial evidence of alternative ways for pharmacological interference.

Melatonin regulates the antioxidant capacity of sheep granulosa cells through a novel uORF-Nrf2aa mediated Nrf2/KEAP1 pathway

Ovarian dysfunction stands as a prevalent contributor to female infertility, with its etiology intertwined with genetic, autoimmune, and environmental factors. Within the ovarian follicles, granulosa cells (GCs) represent the predominant cell population. Alterations in GCs, notably oxidative stress (OS) and the consequential surge in reactive oxygen species (ROS), play pivotal roles in the orchestration of ovarian function. Nrf2aa, a newly identified upstream open reading frame (uORF), is situated within the 5' untranslated region (5'UTR) of sheep Nrf2 mRNA and is regulated by melatonin, a crucial intrafollicular antioxidant. In this study, we have noted that Nrf2aa has the capacity to encode a peptide and exerts a negative regulatory effect on the translation efficiency (TE) of the Nrf2 CDs region. Further in vitro experiments, we observed that interfering with Nrf2aa can enhance the cellular functionality of GCs under 3-np-induced oxidative stress, while overexpressing Nrf2aa has the opposite effect. Furthermore, overexpression of Nrf2aa counteracts the rescuing effect of melatonin on the cellular functions of GCs under oxidative stress conditions, including estrogen secretion, proliferation, apoptosis, and many more. Finally, we confirmed that Nrf2aa, by regulating the expression of key proteins in the Nrf2/KEAP1 signaling pathway, further modulates the antioxidant levels in GCs.

NRF2-dependent regulation of the prostacyclin receptor PTGIR drives CD8 T cell exhaustion

The progressive decline of CD8 T cell effector function-also known as terminal exhaustion-is a major contributor to immune evasion in cancer. Yet, the molecular mechanisms that drive CD8 T cell dysfunction remain poorly understood. Here, we report that the Kelch-like ECH-associated protein 1 (KEAP1)-Nuclear factor erythroid 2-related factor 2 (NRF2) signaling axis, which mediates cellular adaptations to oxidative stress, directly regulates CD8 T cell exhaustion. Transcriptional profiling of dysfunctional CD8 T cells from chronic infection and cancer reveals enrichment of NRF2 activity in terminally exhausted (Texterm) CD8 T cells. Increasing NRF2 activity in CD8 T cells (via conditional deletion of KEAP1) promotes increased glutathione production and antioxidant defense yet accelerates the development of terminally exhausted (PD-1+TIM-3+) CD8 T cells in response to chronic infection or tumor challenge. Mechanistically, we identify PTGIR, a receptor for the circulating eicosanoid prostacyclin, as an NRF2-regulated protein that promotes CD8 T cell dysfunction. Silencing PTGIR expression restores the anti-tumor function of KEAP1-deficient T cells. Moreover, lowering PTGIR expression in CD8 T cells both reduces terminal exhaustion and enhances T cell effector responses (i.e. IFN-γ and granzyme production) to chronic infection and cancer. Together, these results establish the KEAP1-NRF2 axis as a metabolic sensor linking oxidative stress to CD8 T cell dysfunction and identify the prostacyclin receptor PTGIR as an NRF2-regulated immune checkpoint that regulates CD8 T cell fate decisions between effector and exhausted states.

Extraction, structural characterization, and antioxidant activity of polysaccharides from three microalgae

Microalgal polysaccharides have received much attention due to their potential value in preventing and regulating oxidative damage. This study aims to reveal the mechanisms of regulating oxidative stress and the differences in the yield, structure, and effect of polysaccharides extracted from three microalgae: Golenkinia sp. polysaccharides (GPS), Chlorella sorokiniana polysaccharides (CPS), and Spirulina subsalsa polysaccharides (SPS). Using the same extraction method, GPS, CPS, and SPS were all heteropoly- saccharides composed of small molecular fraction: the monosaccharides mainly comprised galactose (Gal). Among the three, SPS had a higher proportion of small molecular fraction, and a higher proportion of Gal; thus it had the highest yield and antioxidant activity. GPS, CPS, and SPS all showed strong antioxidant activity in vitro, and showed strong ability to regulate oxidative stress, among which SPS was slightly higher. From the analysis of gene expression, the Nrf2-ARE signalling pathway was an important pathway for GPS, CPS, and SPS to regulate cellular oxidative stress. This study provides a theoretical foundation for further research on the utilization of microalgae polysaccharides and product development.

Experimental verification about treatment of Bu-Shen-Yi-Jing-Fang in Alzheimer's disease by the analysis of the feasible signaling pathway of network pharmacology

CONTEXT

Bu-shen-yi-jing-fang (BSYJF) has been reported to reduce amyloid-β (Aβ)1-42 deposition in the brain of APP/PS1 mice and ameliorate cognitive function. However, its neuroprotective mechanism remains unclear.

OBJECTIVE

This study aims to investigate whether BSYJF exerts a protective effect on Aβ1-42-induced oxidative stress injury and explore its possible mechanism.

MATERIALS AND METHODS

The platform databases TCMSP, Swiss, TTD, DrugBank, and GeneCards were used to mine the targets of Alzheimer's disease (AD) and BSYJF. The platform databases STRING and Metascape were used to build the interaction network of the target protein, and Cytoscape software was used to analyze this network and screen out the key pathways. Aβ1-42-treated SKNMC cells were established to verify the mechanism of BSYJF and the key proteins. The downstream proteins and antioxidants as well as apoptosis and ferroptosis of the PI3K/AKT/Nrf2 signaling pathway were validated using an in vitro SKNMC cell model experiment. The expression levels of related proteins were detected using Western blotting. Flow cytometry and immunofluorescence staining were used to analyze apoptosis and ferroptosis.

RESULTS

Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis considered the key signal pathways, mainly involving the PI3K/AKT signaling pathway. Experimental validation demonstrated that BSYJF treatment markedly increased the activity of the PI3K/AKT pathway, which could exert anti-AD effects.

CONCLUSIONS

Our data provided compelling evidence that the protective effects of BSYJF might be associated with their regulation of the PI3K/AKT/Nrf2 signaling pathway. These studies offered a potential therapy for natural herbal medicine treatment of AD.

Comparative Study of the Potential Cell-Penetrating Peptide ∆M4 on Apoptosis Cell Signaling in A375 and A431 Cancer Cell Lines

In recent yearsjajajj, peptide-based therapeutics have attracted increasing interest as a potential approach to cancer treatment. Peptides are characterized by high specificity and low cytotoxicity, but they cannot be considered universal drugs for all types of cancer. Of the numerous anticancer-reported peptides, both natural and synthetic, only a few have reached clinical applications. However, in most cases, the mechanism behind the anticancer activity of the peptide is not fully understood. For this reason, in this work, we investigated the effect of the novel peptide ∆M4, which has documented anticancer activity, on two human skin cancer cell lines. A novel approach to studying the potential induction of apoptosis by anticancer peptides is the use of protein microarrays. The results of the apoptosis protein study demonstrated that both cell types, skin malignant melanoma (A375) and epidermoid carcinoma (A431), exhibited markers associated with apoptosis and cellular response to oxidative stress. Additionally, ∆M4 induced concentration- and time-dependent moderate ROS production, triggering a defensive response from the cells, which showed decreased activation of cytoplasmic superoxide dismutase. However, the studied cells exhibited a differential response in catalase activity, with A375 cells showing greater resistance to the peptide action, possibly mediated by the Nrf2 pathway. Nevertheless, both cell types showed moderate activity of caspases 3/7, suggesting that they may undergo partial apoptosis, although another pathway of programmed death cannot be excluded. Extended analysis of the mechanisms of action of anticancer peptides may help determine their effectiveness in overcoming chemoresistance in cancerous cells.

Salidroside protects pulmonary artery endothelial cells against hypoxia-induced apoptosis via the AhR/NF-κB and Nrf2/HO-1 pathways

BACKGROUND

The apoptosis of pulmonary artery endothelial cells (PAECs) is an important factor contributing to the development of pulmonary hypertension (PH), a serious cardio-pulmonary vascular disorder. Salidroside (SAL) is a bioactive compound derived from an herb Rhodiola, but the potential protective effects of SAL on PAECs and the underlying mechanisms remain elusive.

PURPOSE

The objective of this study was to determine the role of SAL in the hypoxia-induced apoptosis of PAECs and to dissect the underlying mechanisms.

STUDY DESIGN

Male Sprague-Dawley (SD) rats were subjected to hypoxia (10% O2) for 4 weeks to establish a model of PH. Rats were intraperitoneally injected daily with SAL (2, 8, and 32 mg/kg/d) or vehicle. To define the molecular mechanisms of SAL in PAECs, an in vitro model of hypoxic cell injury was also generated by exposed PAECs to 1% O2 for 48 h.

METHODS

Various techniques including hematoxylin and eosin (HE) staining, immunofluorescence, flow cytometry, CCK-8, Western blot, qPCR, molecular docking, and surface plasmon resonance (SPR) were used to determine the role of SAL in rats and in PAECs in vitro.

RESULTS

Hypoxia stimulation increases AhR nuclear translocation and activates the NF-κB signaling pathway, as evidenced by upregulated expression of CYP1A1, CYP1B1, IL-1β, and IL-6, resulting in oxidative stress and inflammatory response and ultimately apoptosis of PAECs. SAL inhibited the activation of AhR and NF-κB, while promoted the nuclear translocation of Nrf2 and increased the expression of its downstream antioxidant proteins HO-1 and NQO1 in PAECs, ameliorating the hypoxia-induced oxidative stress in PAECs. Furthermore, SAL lowered right ventricular systolic pressure, and decreased pulmonary vascular remodeling and right ventricular hypertrophy in hypoxia-exposed rats.

CONCLUSIONS

SAL may attenuate the apoptosis of PAECs by suppressing NF-κB and activating Nrf2/HO-1 pathways, thereby delaying the progressive pathology of PH.

Comparing Redox and Intracellular Signalling Responses to Cold Plasma in Wound Healing and Cancer

Cold plasma (CP) is an ionised gas containing excited molecules and ions, radicals, and free electrons, and which emits electric fields and UV radiation. CP is potently antimicrobial, and can be applied safely to biological tissue, birthing the field of plasma medicine. Reactive oxygen and nitrogen species (RONS) produced by CP affect biological processes directly or indirectly via the modification of cellular lipids, proteins, DNA, and intracellular signalling pathways. CP can be applied at lower levels for oxidative eustress to activate cell proliferation, motility, migration, and antioxidant production in normal cells, mainly potentiated by the unfolded protein response, the nuclear factor-erythroid factor 2-related factor 2 (Nrf2)-activated antioxidant response element, and the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway, which also activates nuclear factor-kappa B (NFκB). At higher CP exposures, inactivation, apoptosis, and autophagy of malignant cells can occur via the degradation of the PI3K/Akt and mitogen-activated protein kinase (MAPK)-dependent and -independent activation of the master tumour suppressor p53, leading to caspase-mediated cell death. These opposing responses validate a hormesis approach to plasma medicine. Clinical applications of CP are becoming increasingly realised in wound healing, while clinical effectiveness in tumours is currently coming to light. This review will outline advances in plasma medicine and compare the main redox and intracellular signalling responses to CP in wound healing and cancer.

Wine- and stir-frying processing of Cuscutae Semen enhance its ability to alleviate oxidative stress and apoptosis via the Keap 1-Nrf2/HO-1 and PI3K/AKT pathways in H2O2-challenged KGN human granulosa cell line

BACKGROUND

Cuscutae Semen (CS) has been prescribed in traditional Chinese medicine (TCM) for millennia as an aging inhibitor, an anti-inflammatory agent, a pain reliever, and an aphrodisiac. Its three main forms include crude Cuscutae Semen (CCS), wine-processed CS (WCS), and stir-frying-processed CS (SFCS). Premature ovarian insufficiency (POI) is a globally occurring medical condition. The present work sought a highly efficacious multi-target therapeutic approach against POI with minimal side effects. Finally, it analyzed the relative differences among CCS, WCS and SFCS in terms of their therapeutic efficacy and modes of action against H2O2-challenged KGN human granulosa cell line.

METHODS

In this study, ultrahigh-performance liquid chromatography (UPLC)-Q-ExactiveTM Orbitrap-mass spectrometry (MS), oxidative stress indices, reactive oxygen species (ROS), Mitochondrial membrane potential (MMP), real-time PCR, Western blotting, and molecular docking were used to investigate the protective effect of CCS, WCS and SFCS on KGN cells oxidative stress and apoptosis mechanisms.

RESULTS

The results confirmed that pretreatment with CCS, WCS and SFCS reduced H2O2-induced oxidative damage, accompanied by declining ROS levels and malondialdehyde (MDA) accumulation in the KGN cells. CCS, WCS and SFCS upregulated the expression of antioxidative levels (GSH, GSH/GSSG ratio, SOD, T-AOC),mitochondrial membrane potential (MMP) and the relative mRNA(Nrf2, Keap1, NQO-1, HO-1, SOD-1, CAT). They inhibited apoptosis by upregulating Bcl-2, downregulating Bax, cleaved caspase-9, and cleaved caspase-3, and lowering the Bax/Bcl-2 ratio. They also exerted antioxidant efficacy by partially activating the PI3K/Akt and Keap1-Nrf2/HO-1 signaling pathways.

CONCLUSIONS

The results of the present work demonstrated the inhibitory efficacy of CCS, WCS and SFCS against H2O2-induced oxidative stress and apoptosis in KGN cells and showed that the associated mechanisms included Keap1-Nrf2/HO-1 activation, P-PI3K upregulation, and P-Akt-mediated PI3K-Akt pathway induction.

Electroacupuncture reduces oxidative stress response and improves secondary injury of intracerebral hemorrhage in rats by activating the peroxisome proliferator-activated receptor-γ/nuclear factor erythroid2-related factor 2/γ-glutamylcysteine synthetase pathway

Intracerebral hemorrhage (ICH) is a severe stroke subtype. Secondary injury is a key factor leading to neurological deficits after ICH. Electroacupuncture (EA) can improve the neurological function after ICH, however, its internal mechanism is still unclear. The aim of this study is to investigate whether EA could ameliorate secondary injury after ICH through antioxidative stress and its potential regulatory mechanism. A rat model of ICH was established by injecting autologous blood into striatum. After the intervention of EA and EA combined with peroxisome proliferator-activated receptor-γ (PPARγ) blocker, Zea-longa scores, modified neurological severity scores and open field tests were used to evaluate the neurological function of the rats. Flow cytometry detected tissue reactive oxygen species (ROS) levels. Tissue tumor necrosis factor-α (TNF-α) levels were analyzed by enzyme-linked immunosorbent assays. The protein expressions of PPAR γ, nuclear factor erythroid2-related factor 2 (Nrf2) and γ-glutamylcysteine synthetase (γ-GCS) were detected by Western blot. Immunohistochemistry was used to observe the activation of microglia. The demyelination degree of axon myelin was observed by transmission electron microscope. Compared with the model group, EA intervention improved neurological function, decreased ROS and TNF-α levels, increased the protein expression of PPARγ, Nrf2 and γ-GCS, and reduced the activation of microglia, it also alleviated axonal myelin sheath damage. In addition, the neuroprotective effect of EA was partially attenuated by PPARγ blocker. EA ameliorated the neurological function of secondary injury after ICH in rats, possibly by activating the PPARγ/Nrf2/γ-GCS signaling pathway, reducing microglia activation, and inhibiting oxidative stress, thus alleviating the extent of axonal demyelination plays a role.

NLRX1 Inhibits LPS-Induced Microglial Death via Inducing p62-Dependent HO-1 Expression, Inhibiting MLKL and Activating PARP-1

The activation of microglia and the production of cytokines are key factors contributing to progressive neurodegeneration. Despite the well-recognized neuronal programmed cell death regulated by microglial activation, the death of microglia themselves is less investigated. Nucleotide-binding oligomerization domain, leucine-rich repeat-containing X1 (NLRX1) functions as a scaffolding protein and is involved in various central nervous system diseases. In this study, we used the SM826 microglial cells to understand the role of NLRX1 in lipopolysaccharide (LPS)-induced cell death. We found LPS-induced cell death is blocked by necrostatin-1 and zVAD. Meanwhile, LPS can activate poly (ADP-ribose) polymerase-1 (PARP-1) to reduce DNA damage and induce heme oxygenase (HO)-1 expression to counteract cell death. NLRX1 silencing and PARP-1 inhibition by olaparib enhance LPS-induced SM826 microglial cell death in an additive manner. Less PARylation and higher DNA damage are observed in NLRX1-silencing cells. Moreover, LPS-induced HO-1 gene and protein expression through the p62-Keap1-Nrf2 axis are attenuated by NLRX1 silencing. In addition, the Nrf2-mediated positive feedback regulation of p62 is accordingly reduced by NLRX1 silencing. Of note, NLRX1 silencing does not affect LPS-induced cellular reactive oxygen species (ROS) production but increases mixed lineage kinase domain-like pseudokinase (MLKL) activation and cell necroptosis. In addition, NLRX1 silencing blocks bafilomycin A1-induced PARP-1 activation. Taken together, for the first time, we demonstrate the role of NLRX1 in protecting microglia from LPS-induced cell death. The underlying protective mechanisms of NLRX1 include upregulating LPS-induced HO-1 expression via Nrf2-dependent p62 expression and downstream Keap1-Nrf2 axis, mediating PARP-1 activation for DNA repair via ROS- and autophagy-independent pathway, and reducing MLKL activation.

MicroRNAs in the Pathogenesis of Preeclampsia-A Case-Control In Silico Analysis

Preeclampsia (PE) occurs in 5% to 7% of all pregnancies, and the PE that results from abnormal placentation acts as a primary cause of maternal and neonatal morbidity and mortality. The objective of this secondary analysis was to elucidate the pathogenesis of PE by probing protein-protein interactions from in silico analysis of transcriptomes between PE and normal placenta from Gene Expression Omnibus (GSE149812). The pathogenesis of PE is apparently determined by associations of miRNA molecules and their target genes and the degree of changes in their expressions with irregularities in the functions of hemostasis, vascular systems, and inflammatory processes at the fetal-maternal interface. These irregularities ultimately lead to impaired placental growth and hypoxic injuries, generally manifesting as placental insufficiency. These differentially expressed miRNAs or genes in placental tissue and/or in blood can serve as novel diagnostic and therapeutic biomarkers.

Keap1-Nrf2 pathway: a key mechanism in the occurrence and development of cancer

The Keap1-Nrf2 signaling pathway is a major regulator of the cytoprotective response, participating in endogenous and exogenous stress caused by ROS (reactive oxygen species). Nrf2 is the core of this pathway. We summarized the literature on Keap1-Nrf2 signaling pathway and summarized the following three aspects: structure, function pathway, and cancer and clinical application status. This signaling pathway is similar to a double-edged sword: on the one hand, Nrf2 activity can protect cells from oxidative and electrophilic stress; on the other hand, increasing Nrf2 activity can enhance the survival and proliferation of cancer cells. Notably, oxidative stress is also considered a marker of cancer in humans. Keap1-Nrf2 signaling pathway, as a typical antioxidant stress pathway, is abnormal in a variety of human malignant tumor diseases (such as lung cancer, liver cancer, and thyroid cancer). In recent years, research on the Keap1-Nrf2 signaling pathway has become increasingly in-depth and detailed. Therefore, it is of great significance for cancer prevention and treatment to explore the molecular mechanism of the occurrence and development of this pathway.

TOM40 mediates the effect of TSPO on postpartum depression partially through regulating calcium homeostasis in microglia

AIMS

To assess the effect of the translocator protein 18 kDa (TSPO) on postpartum depression and explore its mechanism.

METHODS

Postpartum depression (PPD) mouse model was established, and flow cytometry, immunofluorescence, Western blot analysis, real-time quantitative PCR, adeno-associated virus (AAV), co-immunoprecipitation-mass spectrometry and immunofluorescence co-staining were used to detect the effect of TSPO ligand ZBD-2 on PPD mice.

RESULTS

ZBD-2 inhibits the overactivation of microglia in the hippocampus and amygdala of PPD model mice. ZBD-2 not only inhibited the inflammation but also repressed the burst of reactive oxygen species (ROS) and mitochondrial ROS (mtROS). Meanwhile, ZBD-2 protects mitochondria from LPS-induced damages through inhibiting the influx of calcium. ZBD-2 modulated the calcium influx by increasing the level of translocase of the outer mitochondrial membrane 40 (TOM40) and reducing the interaction of TSPO and TOM40. In addition, the effect of ZBD-2 was partially dependent on anti-oxidative process. Knockdown of TOM40 by adeno-associated virus (AAV) in the hippocampus or amygdala dramatically reduced the effect of ZBD-2 on PPD, indicating that TOM40 mediates the effect of ZBD-2 on PPD.

CONCLUSIONS

TOM40 is required for the effect of ZBD-2 on treating anxiety and depression in PPD mice. This study reveals the role of microglia TSPO in PPD development and provides the new therapeutic strategy for PPD.

Structure characterization of polysaccharides from Cistanche deserticola and their neuroprotective effects against oxidative stress in slow transit constipation mice

Oxidative stress-induced enteric neuropathy is an important factor in slow transit constipation (STC). Cistanche deserticola crude polysaccharides (CDCP) are natural antioxidants with various biological activities. We prepared CDCP through water-extract and alcohol-precipitation methods. The structural characteristics of CDCP were analyzed by infrared spectroscopy and methylation analysis. The results showed that CDCP was primarily composed of (1 → 4)-linked glucans with minor amounts of pectic polysaccharides. Different doses of CDCP (100, 200, and 400 mg/kg) were administered to loperamide-induced STC mice to explore the therapeutic effects of CDCP. Compared with the untreated group, CDCP treatment significantly improved constipation symptoms, relevant gut-regulating peptides levels, colonic pathological damage, and colonic myenteric nerons injury. CDCP enhanced the antioxidant capacity by decreasing Malondialdehyde (MDA) content, increasing Superoxide Dismutase (SOD) activity and Reduced Glutathione (GSH) content. CDCP significantly reduced oxidative stress-induced injury by preserving mitochondrial function in the colonic myenteric plexus. Furthermore, the neuroprotective effects of CDCP might be associated with the Nrf2/Keap1 pathway. Thus, our findings first revealed the potential of CDCP to protect the colonic myenteric plexus against oxidative stress-induced damage in STC, establishing CDCP as promising candidates for natural medicine in the clinical management of STC.

Age-Dependent Changes in Nrf2/Keap1 and Target Antioxidant Protein Expression Correlate to Lipoxidative Adducts, and Are Modulated by Dietary N-3 LCPUFA in the Hippocampus of Mice

The brain has a high metabolism rate that may generate reactive oxygen and nitrogen species. Consequently, nerve cells require highly efficient antioxidant defenses in order to prevent a condition of deleterious oxidative stress. This is particularly relevant in the hippocampus, a highly complex cerebral area involved in processing superior cognitive functions. Most current evidence points to hippocampal oxidative damage as a causal effect for neurodegenerative disorders, especially Alzheimer's disease. Nuclear factor erythroid-2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) is a master key for the transcriptional regulation of antioxidant and detoxifying systems. It is ubiquitously expressed in brain areas, mainly supporting glial cells. In the present study, we have analyzed the relationships between Nrf2 and Keap1 isoforms in hippocampal tissue in response to aging and dietary long-chain polyunsaturated fatty acids (LCPUFA) supplementation. The possible involvement of lipoxidative and nitrosative by-products in the dynamics of the Nrf2/Keap1 complex was examined though determination of protein adducts, namely malondialdehyde (MDA), 4-hydroxynonenal (HNE), and 3-nitro-tyrosine (NTyr) under basal conditions. The results were correlated to the expression of target proteins heme-oxygenase-1 (HO-1) and glutathione peroxidase 4 (GPx4), whose expressions are known to be regulated by Nrf2/Keap1 signaling activation. All variables in this study were obtained simultaneously from the same preparations, allowing multivariate approaches. The results demonstrate a complex modification of the protein expression patterns together with the formation of adducts in response to aging and diet supplementation. Both parameters exhibited a strong interaction. Noticeably, LCPUFA supplementation to aged animals restored the Nrf2/Keap1/target protein patterns to the status observed in young animals, therefore driving a "rejuvenation" of hippocampal antioxidant defense.

Nigral transcriptomic profiles in Engrailed-1 hemizygous mouse models of Parkinson's disease reveal upregulation of oxidative phosphorylation-related genes associated with delayed dopaminergic neurodegeneration

Introduction

Parkinson's disease (PD) is the second most common neurodegenerative disorder, increasing both in terms of prevalence and incidence. To date, only symptomatic treatment is available, highlighting the need to increase knowledge on disease etiology in order to develop new therapeutic strategies. Hemizygosity for the gene Engrailed-1 (En1), encoding a conserved transcription factor essential for the programming, survival, and maintenance of midbrain dopaminergic neurons, leads to progressive nigrostriatal degeneration, motor impairment and depressive-like behavior in SwissOF1 (OF1-En1+/-). The neurodegenerative phenotype is, however, absent in C57Bl/6j (C57-En1+/-) mice. En1+/- mice are thus highly relevant tools to identify genetic factors underlying PD susceptibility.

Methods

Transcriptome profiles were defined by RNAseq in microdissected substantia nigra from 1-week old OF1, OF1- En1+/-, C57 and C57- En1+/- male mice. Differentially expressed genes (DEGs) were analyzed for functional enrichment. Neurodegeneration was assessed in 4- and 16-week old mice by histology.

Results

Nigrostriatal neurodegeneration was manifested in OF1- En1+/- mice by increased dopaminergic striatal axonal swellings from 4 to 16 weeks and decreased number of dopaminergic neurons in the SNpc at 16 weeks compared to OF1. In contrast, C57- En1+/- mice had no significant increase in axonal swellings or cell loss in SNpc at 16 weeks. Transcriptomic analyses identified 198 DEGs between OF1- En1+/- and OF1 mice but only 52 DEGs between C57- En1+/- and C57 mice. Enrichment analysis of DEGs revealed that the neuroprotective phenotype of C57- En1+/- mice was associated with a higher expression of oxidative phosphorylation-related genes compared to both C57 and OF1- En1+/- mice.

Discussion

Our results suggest that increased expression of genes encoding mitochondrial proteins before the onset of neurodegeneration is associated with increased resistance to PD-like nigrostriatal neurodegeneration. This highlights the importance of genetic background in PD models, how different strains can be used to model clinical and sub-clinical pathologies and provides insights to gene expression mechanisms associated with PD susceptibility and progression.

Metalloproteins and metalloproteomics in health and disease

Metalloproteins represents more than one third of human proteome, with huge variation in physiological functions and pathological implications, depending on the metal/metals involved and tissue context. Their functions range from catalysis, bioenergetics, redox, to DNA repair, cell proliferation, signaling, transport of vital elements, and immunity. The human metalloproteomic studies revealed that many families of metalloproteins along with individual metalloproteins are dysregulated under several clinical conditions. Also, several sorts of interaction between redox- active or redox- inert metalloproteins are observed in health and disease. Metalloproteins profiling shows distinct alterations in neurodegenerative diseases, cancer, inflammation, infection, diabetes mellitus, among other diseases. This makes metalloproteins -either individually or as families- a promising target for several therapeutic approaches. Inhibitors and activators of metalloenzymes, metal chelators, along with artificial metalloproteins could be versatile in diagnosis and treatment of several diseases, in addition to other biomedical and industrial applications.