The multifaceted role of Nrf2 in mitochondrial function

Role of Mitochondrial Dysfunctions in Neurodegenerative Disorders: Advances in Mitochondrial Biology

Mitochondria, essential organelles responsible for cellular energy production, emerge as a key factor in the pathogenesis of neurodegenerative disorders. This review explores advancements in mitochondrial biology studies that highlight the pivotal connection between mitochondrial dysfunctions and neurological conditions such as Alzheimer's, Parkinson's, Huntington's, ischemic stroke, and vascular dementia. Mitochondrial DNA mutations, impaired dynamics, and disruptions in the ETC contribute to compromised energy production and heightened oxidative stress. These factors, in turn, lead to neuronal damage and cell death. Recent research has unveiled potential therapeutic strategies targeting mitochondrial dysfunction, including mitochondria targeted therapies and antioxidants. Furthermore, the identification of reliable biomarkers for assessing mitochondrial dysfunction opens new avenues for early diagnosis and monitoring of disease progression. By delving into these advancements, this review underscores the significance of understanding mitochondrial biology in unraveling the mechanisms underlying neurodegenerative disorders. It lays the groundwork for developing targeted treatments to combat these devastating neurological conditions.

Hydrogen sulfide (H2S) coordinates redox balance, carbon metabolism, and mitochondrial bioenergetics to suppress SARS-CoV-2 infection

Viruses modulate various aspects of host physiology, including carbon metabolism, redox balance, and mitochondrial bioenergetics to acquire the building blocks for replication and regulation of the immune response. Understanding how SARS-CoV-2 alters the host metabolism may lead to treatments for COVID-19. We report that a ubiquitous gaseous molecule, hydrogen sulfide (H2S), regulates redox, metabolism, and mitochondrial bioenergetics to control SARS-CoV-2. Virus replication is associated with down-regulation of the H2S-producing enzymes cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CTH), and 3-mercaptopyruvate sulfurtransferase (3-MST) in multiple cell lines and nasopharyngeal swabs of symptomatic COVID-19 patients. Consequently, SARS-CoV-2-infected cells showed diminished endogenous H2S levels and a protein modification (S-sulfhydration) caused by H2S. Genetic silencing or chemical inhibition of CTH resulted in SARS-CoV-2 proliferation. Chemical supplementation of H2S using a slow-releasing H2S donor, GYY4137, diminished virus replication. Using a redox biosensor, metabolomics, transcriptomics, and XF-flux analyzer, we showed that GYY4137 blocked SARS-CoV-2 replication by inducing the Nrf2/Keap1 pathway, restoring redox balance and carbon metabolites and potentiating mitochondrial oxidative phosphorylation. Treatment of SARS-CoV-2-infected mice or hamsters with GYY4137 suppressed viral replication and ameliorated lung pathology. GYY4137 treatment reduced the expression of inflammatory cytokines and re-established the expression of Nrf2-dependent antioxidant genes in the lungs of SARS-CoV-2-infected mice. Notably, non-invasive measurement of respiratory functions using unrestrained whole-body plethysmography (uWBP) of SARS-CoV-2-infected mice showed improved pulmonary function variables, including pulmonary obstruction (Penh), end-expiratory pause (EEP), and relaxation time (RT) upon GYY4137 treatment. Together, our findings significantly extend our understanding of H2S-mediated regulation of viral infections and open new avenues for investigating the pathogenic mechanisms and therapeutic opportunities for coronavirus-associated disorders.

Weissella viridescens Attenuates Hepatic Injury, Oxidative Stress, and Inflammation in a Rat Model of High-Fat Diet-Induced MASLD

Background: Metabolic-dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disorder globally. Probiotic supplementation has shown promise in its prevention and treatment. Although Weissella viridescens, a lactic acid bacterium with immunomodulatory effects, has antibacterial and anti-inflammatory activities, there is a lack of direct evidence for its role in alleviating MASLD. This study aimed to investigate the protective effects of W. viridescens strain Wv2365, isolated from healthy human feces, in a high-fat diet (HFD)-induced rat model of MASLD. Methods: Rats were randomly assigned to a normal chow diet (NC), high-fat diet (HFD), and HFD supplemented with W. viridescens Wv2365 (Wv2365) groups. All groups were fed their respective diets for 8 weeks. During this period, the NC and HFD groups received a daily oral gavage of PBS, while the Wv2365 group received a daily oral gavage of Wv2365. Results: Wv2365 supplementation significantly reduced HFD-induced body weight gain, improved NAFLD activity scores, alleviated hepatic injury, and restored lipid metabolism. A liver transcriptomic analysis revealed the downregulation of inflammation-related pathways, along with decreased serum levels of TNF-α, IL-1β, IL-6, MCP-1, and LPS. Wv2365 also activated the Nrf2/HO-1 antioxidant pathway, enhanced hepatic antioxidant enzyme activities and reduced malondialdehyde levels. A gut microbiota analysis showed the enrichment of beneficial genera, including Butyricicoccus, Akkermansia, and Blautia. Serum metabolomic profiling revealed increased levels of metabolites including indole-3-propionic acid, indoleacrylic acid, and glycolithocholic acid. Conclusions: Wv2365 attenuates hepatic injury, oxidative stress, and inflammation in a rat model of high-fat-diet-induced MASLD, supporting its potential as a probiotic candidate for the modulation of MASLD.

Diroximel Fumarate Acts Through Nrf2 to Attenuate Methylglyoxal-Induced Nociception in Mice and Decrease ISR Activation in DRG Neurons

Diabetic neuropathic pain is associated with elevated plasma levels of methylglyoxal (MGO). MGO is a metabolite of glycolysis that causes pain hypersensitivity in mice by stimulating the phosphorylation of eukaryotic initiation factor 2α (p-eIF2α) and subsequently activating the integrated stress response (ISR). We first established that Zucker diabetic fatty rats have enhanced MGO signaling, engage ISR, and develop pain hypersensitivity. Since nuclear factor erythroid 2-related factor 2 (Nrf2) regulates the expression of antioxidant proteins that neutralize MGO, we hypothesized that fumarates, like diroximel fumarate (DRF), will stimulate Nrf2 signaling, and prevent MGO-induced ISR and pain hypersensitivity. DRF (100 mg/kg) treated animals were protected from developing MGO (20 ng) induced mechanical and cold hypersensitivity. Mechanistically, DRF treatment protected against MGO-induced increase in p-eIF2α levels in the sciatic nerve and reduced loss of intraepidermal nerve fiber density. Using Nrf2 knockout mice, we demonstrate that Nrf2 is necessary for the antinociceptive effects of DRF. Cotreatment of MGO (1 µmol/L) with monomethyl fumarate (10, 20, and 50 µmol/L), the active metabolite of DRF, prevented ISR in both mouse and human dorsal root ganglia neurons. Our data show that targeting Nrf2 with DRF is a strategy to potentially alleviate pain associated with elevated MGO levels.

ARTICLE HIGHLIGHTS

Folate-Associated Gene Expression in Primary Tumors Is Associated With Tumor Response and Progression-Free Survival of Patients With Metastatic Colorectal Cancer Undergoing 5-FU/Leucovorin-Based Combination Chemotherapy

BACKGROUND

5-Fluorouracil (5-FU) and the Folate Leucovorin (LV) form the chemotherapy backbone for metastatic colorectal cancer (mCRC). Tumoral expression of specific folate-associated genes is associated with the risk of recurrence in stage III CRC following adjuvant 5-FU/LV (FLV)-based combination chemotherapy according to the Nordic bolus regimen. The aim was to evaluate whether expression of folate-associated genes in Pre-therapeutic tumor samples is associated with outcomes of patients with mCRC undergoing palliative FLV-based combination chemotherapy.

PATIENTS AND METHODS

Patients treated with FLV (n = 113), FLV + oxaliplatin (FLOX, n = 102), or FLV + irinotecan (FLIRI, n = 75) were included. ABCC3, RFC-1, PCFT, MFT, MTHFD2, and TYMS expression was determined by qPCR and related to tumor response and 3-year progression-free survival (PFS). Analyses were conducted on the entire cohort and on subgroups (group 1: stage I-III; group 2: stage IV, at primary surgery). Multivariate Cox proportional hazard models were applied to assess associations between covariates and PFS.

RESULTS

Low TYMS and high MFT expression in group 1, and high ABCC3 expression in group 2 correlated with better PFS (HR 1.37 (1.04-1.82), HR 0.49 (0.30-0.80), and HR 0.74 (0.60-0.93)), respectively. In addition, high MFT expression was associated with better PFS of patients treated with FLIRI (HR 0.47 (0.27-0.81), p = 0.007) whereas high expression of ABCC3 was associated with better PFS of patients treated with FLOX (HR 0.46 (0.23-0.92), p = 0.029).

CONCLUSION

While pretherapeutic tumoral expression of specific folate-associated genes may not serve as a universal predictive marker for FLV-based treatment, it might predict response and outcomes in patients receiving FLOX or FLIRI. Evaluating the impact of gene expression in primary tumors should consider subgrouping of patients by disease stage at diagnosis as well as the applied chemotherapy regimen. Prospective clinical studies on patients with mCRC are warranted to validate these findings.

Repurposing of epalrestat for neuroprotection in parkinson's disease via activation of the KEAP1/Nrf2 pathway

BACKGROUND

Epalrestat (EPS), an aldose reductase inhibitor, is used to alleviate peripheral nerve disorder of diabetic patients in clinical therapy. Even though EPS exerted effects in central nervous system diseases, the neuroprotection and underlying molecular mechanism in neurodegenerative diseases, especially Parkinson's disease (PD), remains obscure. Our study aimed to investigate the potential of EPS suppressed PD progression both in vivo and in vitro.

METHODS

We used 1-methyl-4-phenylpyridillium ion (MPP+)-treated PD cells and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated PD mice to investigate the protective function and molecular mechanism of EPS in PD. EPS was administered three times daily through oral route 3 days before model establishment for 5 consecutive days. Behavioral manifestation of mice was conducted using open field test, rotarod test and CatWalk gait analysis. Immunofluorescence was used to detect dopaminergic (DAergic) neurons survival in the substantia nigra. Subsequently, oxidative stress, mitochondrial function and KEAP1/Nrf2 signaling pathway in PD models were detected through molecular biology methods to assess the effect and downstream mechanisms of EPS on PD. Molecular docking, surface plasmon resonance and cellular thermal shift assay were used to verify the direct binding of EPS and KEAP1.

RESULTS

We found that EPS exhibited potent antiparkinsonian activity in PD models both in vivo and in vitro. PD models treated with EPS manifested alleviated oxidative stress and mitochondrial dysfunction. Furthermore, we found EPS activated the Nrf2 signaling pathway which contributed to DAergic neurons survival in PD models. Particularly, we firstly confirmed that EPS competitively binds to KEAP1 and enhanced its degradation, thereby activating the Nrf2 signaling pathway.

CONCLUSIONS

Collectively, EPS attenuates oxidative stress and mitochondrial dysfunction by directly binding KEAP1 to activate the KEAP1/Nrf2 signaling pathway, further reducing DAergic neurons damage. These findings suggest that EPS has great potential to become a therapeutic for PD as a clinically effective and safe medicine.

Mitochondrial dysfunction as a key player in aggravating periodontitis among diabetic patients: review of the current scope of knowledge

Periodontitis is a prevalent inflammatory disease that leads to significant periodontal tissue destruction and compromised dental health, with its severity exacerbated in individuals with Diabetes Mellitus (DM). This review explores the complex relationship between mitochondrial dysfunction and periodontitis in diabetic patients. Recent studies indicate that the excessive production of reactive oxygen species (ROS), primarily generated by dysfunctional mitochondrial electron transport chain (ETC) complexes, contributes to oxidative stress (OS) and subsequent periodontal tissue damage. The interplay between impaired mitochondrial biogenesis, apoptosis of periodontal cells, and ROS accumulation highlights a critical area of concern in understanding the pathophysiology of diabetic periodontitis. Furthermore, altered glycemic control due to inflammatory processes associated with periodontitis may perpetuate a cyclical detriment to oral and systemic health. This review aims to highlight the mechanistic roles of mitochondrial dysfunction in the aggravation of periodontitis among diabetic patients, emphasizing further research to identify potential therapeutic targets and improve treatment efficacy for this dual pathology.

Sulforaphane and Brain Health: From Pathways of Action to Effects on Specific Disorders

The brain accounts for about 2% of the body's weight, but it consumes about 20% of the body's energy at rest, primarily derived from ATP produced in mitochondria. The brain thus has a high mitochondrial density in its neurons because of its extensive energy demands for maintaining ion gradients, neurotransmission, and synaptic activity. The brain is also extremely susceptible to damage and dysregulation caused by inflammation (neuroinflammation) and oxidative stress. Many systemic challenges to the brain can be mitigated by the phytochemical sulforaphane (SF), which is particularly important in supporting mitochondrial function. SF or its biogenic precursor glucoraphanin, from broccoli seeds or sprouts, can confer neuroprotective and cognitive benefits via diverse physiological and biochemical mechanisms. SF is able to cross the blood-brain barrier as well as to protect it, and it mitigates the consequences of destructive neuroinflammation. It also protects against the neurotoxic effects of environmental pollutants, combats the tissue and cell damage wrought by advanced glycation end products (detoxication), and supports healthy glucose metabolism. These effects are applicable to individuals of all ages, from the developing brains in periconception and infancy, to cognitively, developmentally, and traumatically challenged brains, to those in later life as well as those who are suffering with multiple chronic conditions including Parkinson's and Alzheimer's diseases.

Elucidating the neuroprotective potential of arbutin in 3-NPA induced HD-like pathology: Insights from in silico, in vitro, and in vivo models

Huntington's disease (HD) is an inherited, hyperkinetic condition manifested by a triad of motor abnormalities, progressive cognitive impairment, and psychiatric disturbances. Oxidative stress has been implicated among other cellular processes in the pathogenesis of HD. Arbutin, a hydroquinone antioxidant, is reportedly neuroprotective in several animal models of neurodegenerative diseases. Hence, this research aimed to investigate the neuroprotective effect of arbutin against HD using in silico, in vitro, and in vivo experimental approaches. Schrodinger software was used for the in-silico studies, while SH-SY5Y cells were used for in-vitro studies. In the in vivo studies, adult Wistar rats were divided into five groups and 3-nitro propionic acid (3-NPA) (10 mg/kg/day,i.p) alone, and with arbutin (50 and 100 mg/kg/day,i.p.) was administered for 21 days. The body weight and behavioral parameters, including locomotor activity and motor coordination, were assessed on the 1st, 7th, 14th & 21st days. On the 22nd day, animals were sacrificed; the striatum was harvested for biochemical, neurochemical, and histopathological assessment. In silico, results indicated that arbutin showed a good binding affinity for target proteins like Akt and Nrf2. Further, arbutin prevented cell death and oxidative stress in SH-SY5Y cells induced by 3-NPA. In addition, arbutin ameliorated the 3-NPA induced motor impairments, purine nucleoside imbalances (adenosine levels and its metabolites hypoxanthine, xanthine, adenine), oxidative stress, and histological alterations in the experimental animals. In conclusion, the present findings indicate that arbutin could be used as an adjuvant for the management of Huntington's disease.

Neuroprotective Effects of Peanut Skin Extract Against Oxidative Injury in HT-22 Neuronal Cells

Background: Oxidative stress is a key therapeutic target in neurological disorders. As processing wastes from the peanut industry, peanut skins are great sources of antioxidants and possess potential in neuroprotection. Methods: We prepared a peanut skin extract (PSE) and investigated its protective effects against tert-butyl hydroperoxide (t-BHP)-induced oxidative injury in HT-22 neuronal cells. Results: PSE was rich in phenolic compounds (123.90 ± 0.46 mg GAE/g), comprising flavonoids (75.97 ± 0.23 mg RE/g) and proanthocyanidins (53.34 ± 1.58 mg PE/g), and displayed potent radical scavenging activities in chemical-based assays. In HT-22 cells, PSE pretreatment restored oxidative balance and endogenous antioxidant defense disrupted by t-BHP, as evidenced by significant reductions in ROS generation and lipid peroxidation levels, along with enhanced endogenous antioxidants. Specifically, 25 μg/mL PSE pretreatment reduced ROS levels by 53.03%, decreased MDA content by 78.82%, enhanced superoxide dismutase (SOD) activity by 12.42%, and improved the ratio of glutathione (GSH) to oxidized glutathione (GSSG) by 80.34% compared to the t-BHP group. Furthermore, PSE rescued mitochondrial membrane potential collapse, inhibited cytochrome c (Cyt.c) release, and prevented subsequent apoptotic death. Notably, the neuroprotective efficacy of PSE was comparable to that of edaravone, an approved neuroprotective drug. Mechanistic investigations combining network pharmacology and experimental validation revealed that the PI3K/Akt/Nrf2 signaling pathway played a pivotal role in mediating the neuroprotective effects of PSE. Compared to t-BHP-treated cells, 25 µg/mL PSE pretreatment significantly upregulated PI3K/Akt phosphorylation, the expression of Nrf2, and its downstream antioxidant proteins heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase quinone 1 (NQO1). Conclusions: Collectively, these findings demonstrate the potential of PSE as a natural protective agent against oxidative-related neurological disorders.

The ultrastructural and proteomic analysis of mitochondria-associated endoplasmic reticulum membrane in the midbrain of a Parkinson's disease mouse model

Recent studies indicated that the dysregulation of mitochondria-associated endoplasmic reticulum membrane (MAM) could be a significant hub in the pathogenesis of Parkinson's disease (PD). However, little has been known about how MAM altered in PD. This study was aimed to observe morphological changes and analyze proteomic profiles of MAM in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse models. In MPTP-treated mice, transmission electron microscopy was applied for MAM ultrastructural visualization. Nano ultra-high performance liquid chromatography-tandem mass spectrum and bioinformatic analysis were adopted to obtain underlying molecular data of MAM fractions. The loosened, shortened and reduced MAM tethering was found in substantia nigral neurons from MPTP-treated mice. In midbrain MAM proteomics, 158 differentially expressed proteins (DEPs) were identified between two groups. Specific DEPs were validated by western blot and exhibited significantly statistical changes, aligning with proteomic results. Bioinformatic analysis indicated that membrane, cytoplasm and cell projection were three major localizations for DEPs. Biological processes including metabolism, lipid transport, and immunological and apoptotic signaling pathways were greatly affected. For consensus MAM proteins, the enriched pathway analysis revealed the potential relationship between neurodegenerative diseases and MAM. Several biological processes such as peroxisome function and clathrin-mediated endocytosis, were clustered, which provided additional insights into the fundamental molecular pathways associated with MAM. In our study, we demonstrated disrupted ER-mitochondria contacts in an MPTP-induced PD mouse model. The underlying signatures of MAM were revealed by proteomics and bioinformatic analysis, providing valuable insights into its potential role in PD pathogenesis.

METTL14-mediated depression of NEIL1 aggravates oxidative damage and mitochondrial dysfunction of lens epithelial cells through regulating KEAP1/NRF2 pathways

Abnormal base excision repair (BER) pathway and N6-methyladenosine (m6A) of RNA have been proved to be significantly related to age-related cataract (ARC) pathogenesis. However, the relationship between the Nei Endonuclease VIII-Like1 (NEIL1) gene (a representative DNA glycosylase of BER pathway) and its m6A modification remains unclear. Here, we showed that the expression of NEIL1 was decreased in the ARC anterior lens capsules and H2O2-stimulated SRA01/04 cells. Our findings demonstrated that ectopic expression of NEIL1 alleviated DNA oxidative damage, apoptosis and mitochondrial dysfunction through disturbing KEAP1/NRF2 interaction. Furthermore, silencing NEIL1 aggravated H2O2-induced lens opacity, whereas ML334 could mitigate lens cloudy ex vitro in rat lenses. Besides, intravitreal injection of AAV2-NEIL1 alleviated lens opacity in Emory mice in vivo. Mechanistically, the N(6)-Methyladenosine (m6A) methyltransferase-like 14 (METTL14) was identified as a factor in promoting m6A modification of NEIL1, which resulted in the recruitment of YTHDF2 to recognize and impair NEIL1 RNA stability. Collectively, these findings highlight the critical role of the m6A modification in NEIL1 on regulating oxidative stress and mitochondrial homeostasis through KEAP1/NRF2 pathways, providing a new way to explore the pathogenesis of ARC.

Oral Asiatic Acid Improves Cognitive Function and Modulates Antioxidant and Mitochondrial Pathways in Female 5xFAD Mice

Background/Objectives: Extracts of the plant Centella asiatica can enhance mitochondrial function, promote antioxidant activity and improve cognitive deficits. Asiatic acid (AA) is one of the constituent triterpene compounds present in the plant. In this study, we explore the effects of AA on brain mitochondrial function, antioxidant response and cognition in a beta-amyloid (Aβ)-overexpressing 5xFAD mouse line. Methods: Six- to seven-month-old 5xFAD mice were treated with 1% AA for 4 weeks. In the last week of treatment, associative memory was assessed along with mitochondrial bioenergetics and the expression of mitochondrial and antioxidant response genes from isolated cortical synaptosomes. The Aβ plaque burden was also evaluated. Results: AA treatment resulted in improvements in associative memory in female 5xFAD mice without altering the Aβ plaque burden. Cortical mitochondrial function and mitochondrial gene expression were increased in the AA-treated female 5xFAD mice, as was the expression of antioxidant genes. More modest effects of AA on cortical mitochondrial function and mitochondrial and antioxidant gene expression were observed in male 5xFAD mice. Conclusions: Oral AA treatment improved cognitive and mitochondrial function and activated antioxidant in Aβ-overexpressing mice. These changes occurred independent of alterations in Aβ plaque burden, suggesting that AA could have translational therapeutic relevance in later-stage AD when plaques are well established.

Olfactory mucosa-mesenchymal stem cells with overexpressed Nrf2 modulate angiogenesis and exert anti-inflammation effect in an in vitro traumatic brain injury model

BACKGROUND

Traumatic brain injury (TBI) is a major cause of disability and mortality among children and adults in developed countries. Transcription factor nuclear factor erythroid-derived 2-like 2 (Nrf2) has antioxidant, anti-inflammatory and neuroprotective effects and is closely related to TBI. Olfactory mucosa-mesenchymal stem cells (OM-MSCs) could promote neural regeneration. At present, the effects of OM-MSCs with overexpressed Nrf2 in brain diseases remain to be explored.

METHODS

The OM-MSCs were prepared and transfected with Nrf2 overexpression plasmid. Those transfected cells were termed as OM-MSCs with Nrf2 overexpression (OM-MSCsNrf2) and co-cultured with rat pheochromocytoma cells PC12 or murine microglia BV2. The effects of OM-MSCsNrf2 on the survival and angiogenesis of PC12 cells were evaluated through cell counting kit-8 (CCK-8) and tube formation assay, and extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were calculated to reflect glycolysis. Immunofluorescence assay was applied to determine the effects of OM-MSCsNrf2 on microglial polarization, and the underlying molecular mechanisms were analyzed based on the quantification tests of RT-qPCR and immunoblotting.

RESULTS

Co-culture of OM-MSCsNrf2 and PC12 cells increased the levels of anti-inflammatory cytokines and pro-angiogenesis factors, enhanced the cell survival and angiogenesis. Moreover, we also observed elevated phosphorylation of PI3K/AKT and suppressed BAX protein expression. Meanwhile, OM-MSCsNrf2 inhibited the levels of pro-inflammatory genes and affected the glycolysis in PC12 cells. In the co-cultured system of OM-MSCsNrf2 and BV2 cells, M2 microglial polarization was observed, and the levels of M2 microglia-relevant genes and the phosphorylation of STAT6/AMPKα/SMAD3 were elevated.

CONCLUSION

This study proved the effects of OM-MSCsNrf2 on modulating PC12 and BV2 cells in vitro, which, however, necessitates further in vivo validation.

Harnessing Evolution and Biomimetics to Enhance Planetary Health: Kidney Insights

Planetary health encompasses the understanding that the long-term well-being of humanity is intrinsically linked to the health of global ecological systems. Unfortunately, current practices often overlook this principle, leading to a human-oriented (anthropocentric) worldview that has resulted in heightened greenhouse gas emissions, increased heat stress, lack of access to clean water, and pollution, threatening both the environment and health and survival of Homo sapiens and countless other species. One significant consequence of these environmental changes is the exacerbation of inflammatory and oxidative stressors, which not only contributes to common lifestyle diseases but also accelerates the aging process. We advocate for a shift away from our current anthropocentric frameworks to an approach that focuses on nature's solutions that developed from natural selection over the eons. This approach, which encompasses the field of biomimicry, may provide insights that can help protect against an inflammatory phenotype to mitigate physiological and cellular senescence and provide a buffer against environmental stressors. Gaining insights from how animals have developed ingenious approaches to combat adversity through the evolutionary process of natural selection not only provides solutions for climate change but also confronts the rising burden of lifestyle diseases that accumulate with age.

The role of resveratrol in neurogenesis: a systematic review

CONTEXT

Resveratrol (RV) is a natural compound found in grapes, wine, berries, and peanuts and has potential health benefits-namely, neurogenesis improvement. Neurogenesis, which is the process through which new neurons or nerve cells are generated in the brain, occurs in the subventricular zone and hippocampus and is influenced by various factors. RV has been shown to increase neural stem cell proliferation and survival, improving cognitive function in hippocampus-dependent tasks. Thus, to provide a convergent and unbiased conclusion of the available evidence on the correlation between the RV and neurogenesis, a systematic review needs to be undertaken meticulously and with appropriate attention.

OBJECTIVE

This study aimed to systematically review any potential connection between the RV and neurogenesis in animal models.

DATA SOURCES AND EXTRACTION

Based on the particular selection criteria, 8 original animal studies that investigated the relationship between RV and neurogenesis were included. Studies written in English and published in peer-reviewed journals with no restrictions on the starting date of publication on August 17, 2023, were searched in the Google Scholar and PubMed databases. Furthermore, data were extracted and analyzed independently by 2 researchers and then reviewed by a third researcher, and discrepancies were resolved by consensus. This project followed PRISMA reporting standards.

DATA ANALYSIS

In the studies analyzed in this review, there is a definite correlation between RV and neurogenesis, meaning that RV intake, irrespective of the mechanisms thereof, can boost neurogenesis in both the subventricular zone and hippocampus.

CONCLUSION

This finding, albeit with some limitations, provides a plausible indication of RV's beneficial function in neurogenesis. Indeed, RV intake may result in neurogenesis benefits-namely, cognitive function, mood regulation, stress resilience, and neuroprotection, potentially preventing cognitive decline.

Sulforaphane acutely activates multiple starvation response pathways

Sulforaphane (SFN) is an isothiocyanate derived from cruciferous vegetables that has demonstrated anti-cancer, anti-microbial and anti-oxidant properties. SFN ameliorates various disease models in rodents (e.g., cancer, diabetes, seizures) that are likewise mitigated by dietary restrictions leading us to test the hypothesis that this compound elicits cellular responses consistent with being a fasting/caloric restriction mimetic. Using immortalized human retinal pigment epithelial cells, we report that SFN impacted multiple nutrient-sensing pathways consistent with a fasted state. SFN treatment (i) increased mitochondrial mass and resistance to oxidative stress, (ii) acutely suppressed markers of mTORC1/2 activity via inhibition of insulin signaling, (iii) upregulated autophagy and further amplified autophagic flux induced by rapamycin or nutrient deprivation while concomitantly promoting lysosomal biogenesis, and (iv) acutely decreased glucose uptake and lactate secretion followed by an adaptive rebound that coincided with suppressed protein levels of thioredoxin-interacting protein (TXNIP) due to early transcriptional down-regulation. This early suppression of TXNIP mRNA expression could be overcome with exogenous glucosamine consistent with SFN inhibiting glutamine F6P amidotransferase, the rate limiting enzyme of the hexosamine biosynthetic pathway. SFN also altered levels of multiple glycolytic and tricarboxylic acid (TCA) cycle intermediates while reducing the inhibitory phosphorylation on pyruvate dehydrogenase, indicative of an adaptive cellular starvation response directing pyruvate into acetyl coenzyme A for uptake by the TCA cycle. RNA-seq of cells treated for 4 h with SFN confirmed the activation of signature starvation-responsive transcriptional programs. Collectively, these data support that the fasting-mimetic properties of SFN could underlie both the therapeutic efficacy and potential toxicity of this phytochemical.

The SIRT-1/Nrf2/HO-1 axis: Guardians of neuronal health in neurological disorders

SIRT1 (Sirtuin 1) is a NAD+-dependent deacetylase that functions through nucleoplasmic transfer and is present in nearly all mammalian tissues. SIRT1 is believed to deacetylate its protein substrates, resulting in neuroprotective actions, including reduced oxidative stress and inflammation, increased autophagy, increased nerve growth factors, and preserved neuronal integrity in aging or neurological disease. Nrf2 is a transcription factor that regulates the genes responsible for oxidative stress response and substance detoxification. The activation of Nrf2 guards cells against oxidative damage, inflammation, and carcinogenic stimuli. Several neurological abnormalities and inflammatory disorders have been associated with variations in Nrf2 activation caused by either pharmacological or genetic factors. Recent evidence indicates that Nrf2 is at the center of a complex cellular regulatory network, establishing it as a transcription factor with genuine pleiotropy. HO-1 is most likely a component of a defense mechanism in cells under stress, as it provides negative feedback for cell activation and mediator synthesis. This mediator is upregulated by Nrf2, nitric oxide (NO), and other factors in various inflammatory states. HO-1 or its metabolites, such as CO, may mitigate inflammation by modulating signal transduction pathways. Neurological diseases may be effectively treated by modulating the activity of HO-1. Multiple studies have demonstrated that SIRT1 and Nrf2 share an important connection. SIRT1 enhances Nrf2, activates HO-1, protects against oxidative injury, and decreases neuronal death. This has been associated with numerous neurodegenerative and neuropsychiatric disorders. Therefore, activating the SIRT1/Nrf2/HO-1 pathway may help treat various neurological disorders. This review focuses on the current understanding of the SIRT1 and Nrf2/HO-1 neuroprotective processes and the potential therapeutic applications of their target activators in neurodegenerative and neuropsychiatric disorders.

Unveiling a novel signalling pathway involving NRF2 and PGAM5 in regulating the mitochondrial unfolded protein response in stressed cardiomyocytes

The mitochondrial unfolded protein response (UPRmt) is a conserved signalling pathway that initiates a specific transcriptional programme to maintain mitochondrial and cellular homeostasis under stress. Previous studies have demonstrated that UPRmt activation has protective effects in the pressure-overloaded human heart, suggesting that robust UPRmt stimulation could serve as an intervention strategy for cardiovascular diseases. However, the precise mechanisms of UPRmt regulation remain unclear. In this study, we present evidence that the NRF2 transcription factor is involved in UPRmt activation in cardiomyocytes during conditions of mitochondrial stress. Silencing NRF2 partially reduces UPRmt activation, highlighting its essential role in this pathway. However, constitutive activation of NRF2 via inhibition of its cytosolic regulator KEAP1 does not increase levels of UPRmt activation markers, suggesting an alternative regulatory mechanism independent of the canonical KEAP1-NRF2 axis. Further analysis revealed that NRF2 likely affects UPRmt activation through its interaction with PGAM5 at the mitochondrial membrane. Disruption of PGAM5 in cardiomyocytes subjected to mitochondrial stress reduces the interaction between PGAM5 and NRF2, enhancing nuclear translocation of NRF2 and significantly upregulating the UPRmt in an NRF2-dependent manner. This NRF2-regulated UPRmt amplification improves mitochondrial respiration, reflecting an enhanced capacity for cardiomyocytes to meet elevated energetic demands during mitochondrial stress. Our findings highlight the therapeutic potential of targeting the NRF2-PGAM5-KEAP1 signalling complex to amplify the UPRmt in cardiomyocytes for cardiovascular and other diseases associated with mitochondrial dysfunction. Future studies should aim to elucidate the mechanisms via which NRF2 enhances the protective effects of UPRmt, thereby contributing to more targeted therapeutic approaches.

Nrf2 mitigates sepsis-associated encephalopathy-induced hippocampus ferroptosis via modulating mitochondrial dynamic homeostasis

Sepsis-associated encephalopathy (SAE) is a serious neurological complication accompanied with acute and long-term cognitive dysfunction. Ferroptosis is a newly discovered type of cell death that is produced by iron-dependent lipid peroxidation. Emerging evidence suggests that ferroptosis is involved in SAE. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a mitochondria related gene involved in ferroptosis. However, the role of Nrf2 in SAE and the mechanisms remains elusive. In this study, we found that Nrf2 knockout aggravated cognitive and emotional dysfunction and promoted caecal ligation and puncture (CLP)-induced brain injury and hippocampus ferroptosis as indicated by the increase of ROS, Fe2+ and the levels of proinflammatory cytokines. Meanwhile, the levels of glutathione peroxidase 4 (GPX4), SLC7A11 and glutathionewere downregulatedin Nrf2 knockout group. In vitro experiments showed that mitochondrial ROS, Fe2+ and the expression of Fis1 and Drp1 decreased, and the level of Mfn1 and Opa-1 increased after Nrf2 overexpression. The silence of Nrf2 increased the expression of ROS, MDA and Fe2+, while decreased glutathione, mitochondrial membrane potential (MMP) and cell viability in vitro, indicating Nrf2 improved LPS-induced mitochondrial dysfunction and mitigated hippocampal cells ferroptosis. These results suggest that Nrf2 could inhibit ferroptosis and neuroinflammation in hippocampus and reduce cognitive dysfunction in SAE mice, making it a potential therapeutic target in the treatment of SAE. The protective effects of Nrf2 on the brain may be mediated by maintaining mitochondrial dynamic homeostasis.

Azithromycin induces liver injury in mice by targeting the AMPK/Nrf2 pathway

BACKGROUND

Azithromycin is an antibacterial and anti-inflammatory drug widely used for the treatment of various diseases, including those caused by atypical pathogens, bacterial or viral infections, chronic sinusitis, and bronchial asthma, particularly in pediatric patients. However, concerns have emerged regarding its hepatotoxicity and its precise mechanism of action remains unclear.

OBJECTIVE

To investigate the molecular mechanisms responsible for azithromycin-induced acute liver injury to advance our understanding of the progression and pathogenesis of antibiotic-induced liver damage, and to improve prevention and treatment strategies.

MATERIALS AND METHODS

C57BL/6 mice, Nrf2-/- mice, and primary hepatocytes were used. Primary hepatocytes from mice were isolated using a two-step perfusion method and cultured in vitro via the 'sandwich' culture model.

RESULTS

The exposure to azithromycin resulted in increased apoptosis and reactive oxygen species (ROS) levels. In mouse models, intraperitoneal administration of azithromycin at varying concentrations and time points substantially induced hepatic disarray, swelling, and dysfunction. Azithromycin markedly upregulated the mRNA and protein levels of phosphorylated adenosine-activated protein kinase (AMPK) while downregulating nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and NADPH: quinone oxidoreductase 1 (NQO-1). Moreover, HO-1 and NQO-1 protein levels remained largely unaffected in primary hepatocytes co-cultured with azithromycin in Nrf2-/- mice.

CONCLUSIONS

Our findings suggest that azithromycin-induced acute liver injury is mediated by suppression of Nrf2 activation and ROS production. This sheds light on the potential mechanisms involved in azithromycin-induced liver damage, underscoring the importance of exploring targeted interventions to mitigate the hepatotoxic effects.

From Microcirculation to Aging-Related Diseases: A Focus on Endothelial SIRT1

Silent information regulator sirtuin 1 (SIRT1) is an NAD+-dependent deacetylase with potent anti-arterial aging activities. Its protective function in aging-related diseases has been extensively studied. In the microcirculation, SIRT1 plays a crucial role in preventing microcirculatory endothelial senescence by suppressing inflammation and oxidative stress while promoting mitochondrial function and optimizing autophagy. It suppresses hypoxia-inducible factor-1α (HIF-1α)-mediated pathological angiogenesis while promoting healthy, physiological capillarization. As a result, SIRT1 protects against microvascular dysfunction, such as diabetic microangiopathy, while enhancing exercise-induced skeletal muscle capillarization and energy metabolism. In the brain, SIRT1 upregulates tight junction proteins and strengthens their interactions, thus maintaining the integrity of the blood-brain barrier. The present review summarizes recent findings on the regulation of microvascular function by SIRT1, the underlying mechanisms, and various approaches to modulate SIRT1 activity in microcirculation. The importance of SIRT1 as a molecular target in aging-related diseases, such as diabetic retinopathy and stroke, is underscored, along with the need for more clinical evidence to support SIRT1 modulation in the microcirculation.

Pterostilbene ameliorates oxidative stress and neuronal apoptosis after intracerebral hemorrhage via the sirtuin 1-mediated Nrf2 pathway in vivo and in vitro

INTRODUCTION

Oxidative stress and neuroapoptosis are significant pathological processes that occur in response to intracerebral hemorrhage (ICH), however, the optimal therapeutic strategy to treat these responses remains unknown. Pterostilbene (PTE) influences neural cell survival in in the pathology of a number of neurological diseases, but the mechanisms underlying this influence at present are not clear. The objective of the present study was to examine the potential impact of PTE on mitigating oxidative stress and neuronal apoptosis following ICH, while also elucidating the potential underlying pathways.

MATERIAL & METHOD

For in vivo experimentation, male C57BL/6 mice were used to establish ICH models. Wet-to-dry weight ratios were utilized to assess the degree of cerebral edema in the context of PTE intervention. Behavioral experiments were conducted to evaluate neurological dysfunction and cognitive impairment, and hematoxylin and eosin staining was employed to observe histopathological changes in the brain. Furthermore, oxidative stress levels in hippocampal tissues were measured, and cell apoptosis was examined using TUNEL staining and western blotting techniques. In vitro experiments were conducted to evaluate the extent of oxidative stress and neural apoptosis after sirtuin 1 (SIRT1) siRNA treatment. Immunofluorescence cytochemistry was used to analyze the immunofluorescence colocalization of SIRT1 and NeuN.

RESULT

Mice that experienced ICH exhibited worsening neurological deterioration, increased oxidative stress and neuronal cell apoptosis. However, the addition of PTE was found to lessen these effects. Furthermore, PTE was found to activate the SIRT1-mediated Nrf2 pathway in mice with ICH. When SIRT1 was inhibited, levels of oxidative stress and neuronal apoptosis increased, even in the presence of PTE.

CONCLUSION

The present study provided evidence to indicate that PTE can suppress oxidative damage and neuronal apoptosis following ICH by activating the SIRT1/Nrf2 pathway.

Relative Bioavailability of Omaveloxolone When Capsules Are Sprinkled Over and Mixed in Applesauce Compared With Administration as Intact Omaveloxolone Capsules: A Phase 1, Randomized, Open-Label, Single-Dose, Crossover Study in Healthy Adults

Omaveloxolone (SKYCLARYS®) is approved for the treatment of Friedreich ataxia (FA) in patients aged ≥16 years in the United States and European Union (EU). The recommended dosage is 150 mg administered orally once daily as three 50-mg capsules. However, some patients with FA may have oropharyngeal dysphagia or difficulty swallowing whole capsules; therefore, alternate method(s) of administration are needed. A Phase 1 clinical study in 32 healthy volunteers evaluated the relative bioavailability, safety, and tolerability of a single dose of omaveloxolone when capsule contents were sprinkled on and mixed in applesauce compared to when taken as intact capsules. Palatability when sprinkled on and mixed in applesauce was assessed with a questionnaire. After a single 150-mg dose, the peak and overall exposures of omaveloxolone were similar irrespective of administration method, with the 90% CIs of the geometric least squares mean ratio (%) for maximum plasma concentration (Cmax), AUC0-t, and AUC0-∞ within the 80% to 125% reference intervals. Omaveloxolone was absorbed more slowly as intact capsules (median tmax, 10 h) compared with sprinkled capsule contents over applesauce (median tmax, 6 h). With chronic daily administration of omaveloxolone to treat FA, the 4-h difference in tmax is not considered clinically relevant. Sprinkled omaveloxolone capsule contents on applesauce were well tolerated, with acceptable palatability and no serious adverse events. Given the similar systemic exposure when capsules were swallowed whole, sprinkling omaveloxolone capsule contents on and mixing in applesauce is a feasible alternative method of administering omaveloxolone and has been included in both the United States and EU prescribing information.

Isoflurane preconditioning protects against renal ischemia/reperfusion injury in diabetes via activation of the Brg1/Nrf2/HO-1 signaling pathway

PURPOSE

To examine whether isoflurane preconditioning (IsoP) has a protective effect against renal ischemia/reperfusion injury (I/RI) in diabetic conditions and to further clarify the underlying mechanisms.

METHODS

Control and streptozotocin-induced diabetic rats were randomly assigned to five groups, as follows: normal sham, normal I/R, diabetic sham, diabetic I/R, and diabetic I/R + isoflurane. Renal I/RI was induced by clamping renal pedicle for 45 min followed by reperfusion for 24 h. IsoP was achieved by exposing the rats to 2% isoflurane for 30 min before vascular occlusion. Kidneys and blood were collected after reperfusion for further analysis. Renal histology, blood urea nitrogen, serum creatinine, oxidative stress, inflammatory cytokines, and renal cell apoptosis were assessed. Furthermore, the expression of brahma related gene 1 (Brg1), nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and nuclear factor-κB (NF-κB) were determined.

RESULTS

Compared with control, diabetic rats undergoing I/R presented more severe renal injury, oxidative stress, inflammatory reaction, and apoptosis with the impairment of Brg1/Nrf2/HO-1 signaling. All these alterations were significantly attenuated by pretreatment with isoflurane.

CONCLUSIONS

These findings suggest that isoflurane could alleviate renal I/RI in diabetes, possibly through improving Brg1/Nrf2/HO-1 signaling.

The role of Nrf2 in immune cells and inflammatory autoimmune diseases: a comprehensive review

INTRODUCTION

Nrf2 regulates mild stress, chronic inflammation, and metabolic changes by regulating different immune cells via downstream signaling. Collection of information about the role of Nrf2 in inflammatory autoimmune diseases will better understand the therapeutic potential of targeting Nrf2 in these diseases.

AREAS COVERED

In this review, we comprehensively discussed biological function of Nrf2 in different immune cells, including Nrf2 preventing oxidative tissue injury, affecting apoptosis of immune cells and inflammatory cytokine production. Moreover, we discussed the role of Nrf2 in the development of inflammatory autoimmune diseases.

EXPERT OPINION

Nrf2 binds to downstream signaling molecules and then provides durable protection against different cellular and organ stress. It has emerged as an important target for inflammatory autoimmune diseases. Development of Nrf2 modulator drugs needs to consider factors such as target specificity, short/long term safety, disease indication identification, and the extent of variation in Nrf2 activity. We carefully discussed the dual role of Nrf2 in some diseases, which helps to better target Nrf2 in the future.

Activation of the Keap1/Nrf2 pathway suppresses mitochondrial dysfunction, oxidative stress, and motor phenotypes in C9orf72 ALS/FTD models

Mitochondrial dysfunction is a common feature of C9orf72 amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD); however, it remains unclear whether this is a cause or consequence of the pathogenic process. Analysing multiple aspects of mitochondrial biology across several Drosophila models of C9orf72-ALS/FTD, we found morphology, oxidative stress, and mitophagy are commonly affected, which correlated with progressive loss of locomotor performance. Notably, only genetic manipulations that reversed the oxidative stress levels were also able to rescue C9orf72 locomotor deficits, supporting a causative link between mitochondrial dysfunction, oxidative stress, and behavioural phenotypes. Targeting the key antioxidant Keap1/Nrf2 pathway, we found that genetic reduction of Keap1 or pharmacological inhibition by dimethyl fumarate significantly rescued the C9orf72-related oxidative stress and motor deficits. Finally, mitochondrial ROS levels were also elevated in C9orf72 patient-derived iNeurons and were effectively suppressed by dimethyl fumarate treatment. These results indicate that mitochondrial oxidative stress is an important mechanistic contributor to C9orf72 pathogenesis, affecting multiple aspects of mitochondrial function and turnover. Targeting the Keap1/Nrf2 signalling pathway to combat oxidative stress represents a therapeutic strategy for C9orf72-related ALS/FTD.

Nrf2 as a regulator of energy metabolism and mitochondrial function

Nuclear factor erythroid-2-related factor 2 (Nrf2) is essential for the control of cellular redox homeostasis. When activated, Nrf2 elicits cytoprotective effects through the expression of several genes encoding antioxidant and detoxifying enzymes. Nrf2 can also improve antioxidant defense via the pentose phosphate pathway by increasing NADPH availability to regenerate glutathione. Microarray and genome-wide localization analyses have identified many Nrf2 target genes beyond those linked to its redox-regulatory capacity. Nrf2 regulates several intermediary metabolic pathways and is involved in cancer cell metabolic reprogramming, contributing to malignant phenotypes. Nrf2 also modulates substrate utilization for mitochondrial respiration. Here we review the experimental evidence supporting the essential role of Nrf2 in the regulation of energy metabolism and mitochondrial function.

The Antinociceptive Role of Nrf2 in Neuropathic Pain: From Mechanisms to Clinical Perspectives

Neuropathic pain, a chronic condition resulting from nerve injury or dysfunction, presents significant therapeutic challenges and is closely associated with oxidative stress and inflammation, both of which can lead to mitochondrial dysfunction. The nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, a critical cellular defense mechanism against oxidative stress, has emerged as a promising target for neuropathic pain management. Nrf2 modulators enhance the expression of antioxidant and cytoprotective genes, thereby reducing oxidative damage, inflammation, and mitochondrial impairment. This review explores the antinociceptive effects of Nrf2, highlighting how pharmacological agents and natural compounds may be used as potential therapeutic strategies against neuropathic pain. Although preclinical studies demonstrate significant pain reduction and improved nerve function through Nrf2 activation, several clinical challenges need to be addressed. However, emerging clinical evidence suggests potential benefits of Nrf2 modulators in several conditions, such as diabetic neuropathy and multiple sclerosis. Future research should focus on further elucidating the molecular role of Nrf2 in neuropathic pain to optimize its modulation efficacy and maximize clinical utility.

Sulforaphane Effects on Neuronal-like Cells and Peripheral Blood Mononuclear Cells Exposed to 2.45 GHz Electromagnetic Radiation

Exposure to 2.45 GHz electromagnetic radiation (EMR) emitted from commonly used devices has been reported to induce oxidative stress in several experimental models. Our study aims to evaluate the efficacy of sulforaphane, a well-known natural product, in preventing radiation-induced toxic effects caused by a 24 h exposure of SH-SY5Y neuronal-like cells and peripheral blood mononuclear cells (PBMCs) to 2.45 GHz EMR. Cells were exposed to radiation for 24 h in the presence or absence of sulforaphane at different concentrations (5-10-25 µg/mL). Cell viability, mitochondrial activity alterations, the transcription and protein levels of redox markers, and apoptosis-related genes were investigated. Our data showed a reduction in cell viability of both neuronal-like cells and PBMCs caused by EMR exposure and a protective effect of 5 µg/mL sulforaphane. The lowest sulforaphane concentration decreased ROS production and increased the Mitochondrial Transmembrane Potential (Δψm) and the NAD+/NADH ratio, which were altered by radiation exposure. Sulforaphane at higher concentrations displayed harmful effects. The hormetic behavior of sulforaphane was also evident after evaluating the expression of genes coding for Nrf2, SOD2, and changes in apoptosis markers. Our study underlined the vulnerability of neuronal-like cells to mitochondrial dysfunction and oxidative stress and the possibility of mitigating these effects by supplementation with sulforaphane. To our knowledge, there are no previous studies about the effects of SFN on these cells when exposed to 2.45 GHz electromagnetic radiation.

The Interplay of Protein Aggregation, Genetics, and Oxidative Stress in Alzheimer's Disease: Role for Natural Antioxidants and Immunotherapeutics

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that comprises amyloid-beta protein (Aβ) as a main component of neuritic plaques. Its deposition is considered a trigger for AD pathogenesis, progression, and the clinical symptoms of cognitive impairment. Some distinct pathological features of AD include phosphorylation of tau protein, oxidative stress, and mitochondrial dysfunction. These pathological consequences tend to produce reactive oxygen species (ROS), resulting in the dysregulation of various signaling pathways of neuroinflammation and neurodegeneration. The relationship between the Aβ cascade and oxidative stress in AD pathogenesis is like a "chicken and egg" story, with the etiology of the disease regarding these two factors remaining a question of "which comes first." However, in this review, we have tried our best to clarify the interconnection between these two mechanisms and to show the precise cause-and-effect relationship. Based on the above hallmarks of AD, several therapeutic strategies using natural antioxidants, monoclonal antibodies, and vaccines are employed as anti-Aβ therapy to decrease ROS, Aβ burden, chronic neuroinflammation, and synaptic failure. These natural antioxidants and immunotherapeutics have demonstrated significant neuroprotective effects and symptomatic relief in various in vitro and in vivo models, as well as in clinical trials for AD. However, none of them have received final approval to enter the drug market for mitigating AD. In this review, we extensively elaborate on the pitfalls, assurances, and important crosstalk between oxidative stress and Aβ concerning current anti-Aβ therapy. Additionally, we discuss future strategies for the development of more Aβ-targeted approaches and the optimization of AD treatment and mitigation.

Mitochondrial mechanisms in Cerebral Ischemia-Reperfusion Injury: Unravelling the intricacies

Cerebral ischemic stroke is a major contributor to physical impairments and premature death worldwide. The available reperfusion therapies for stroke in the form of mechanical thrombectomy and intravenous thrombolysis increase the risk of cerebral ischemia-reperfusion (I-R) injury due to sudden restoration of blood supply to the ischemic region. The injury is manifested by hemorrhagic transformation, worsening of neurological impairments, cerebral edema, and progression to infarction in surviving patients. A complex network of multiple pathological processes has been known to be involved in the pathogenesis of I-R injury. Primarily, 3 major contributors namely oxidative stress, neuroinflammation, and mitochondrial failure have been well studied in I-R injury. A transcription factor, Nrf2 (Nuclear factor erythroid 2-related factor 2) plays a crucial defensive role in resisting the deleterious effects of I-R injury and potentiating the cellular protective mechanisms. In this review, we delve into the critical function of mitochondria and Nrf2 in the context of cerebral I-R injury. We summarized how oxidative stress, neuroinflammation, and mitochondrial anomaly contribute to the pathophysiology of I-R injury and further elaborated the role of Nrf2 as a pivotal guardian of cellular integrity. The review further highlighted Nrf2 as a putative therapeutic target for mitochondrial dysfunction in cerebral I-R injury management.

Neuro-modulatory impact of felodipine against experimentally-induced Parkinson's disease: Possible contribution of PINK1-Parkin mitophagy pathway

Parkinson's disease (PD) is a prevalent neurodegenerative disorder, characterized by motor and psychological dysfunction. Palliative treatment and dopamine replenishment therapy are the only available therapeutic options. Calcium channel blockers (CCBs) have been reported to protect against several neurodegenerative disorders. The current study was designed to evaluate the neuroprotective impact of Felodipine (10 mg/kg, orally) as a CCB on motor and biochemical dysfunction associated with experimentally induced PD using rotenone (2.5 mg/kg, IP) and to investigate the underlying mechanisms. Rotenone induced deleterious neuromotor outcomes, typical of those associated with PD. The striatum revealed increased oxidative burden and NO levels with decreased antioxidant capacity. Nrf2 content significantly decreased with the accumulation of α-synuclein and tau proteins in both the substantia nigra and striatum. These observations significantly improved with felodipine treatment. Of note, felodipine increased dopamine levels in the substantia nigra and striatum as confirmed by the suppression of inflammation and the significant reduction in striatal NF-κB and TNF-α contents. Moreover, felodipine enhanced mitophagy, as confirmed by a significant increase in mitochondrial Parkin and suppression of LC3a/b and SQSTM1/p62. In conclusion, felodipine restored dopamine synthesis, attenuated oxidative stress, inflammation, and mitochondrial dysfunction, and improved the mitophagy process resulting in improved PD-associated motor impairment.

Potential mitigating impact of a dipeptidyl peptidase-IV inhibitor, vildagliptin, on oxazolone-induced ulcerative colitis: Targeting the role of PI3K/AKT/mTOR and AMPK/Nrf2 signaling pathways

Growing evidence suggests that phosphoinositide 3-kinase (PI3K) and adenosine monophosphate-activated protein kinase (AMPK) signaling cascades are critical in ulcerative colitis (UC) pathophysiology by influencing gut mucosal inflammation. Recently, the coloprotective properties of dipeptidyl peptidase-IV (DPP-IV) inhibitors have emerged. Thus, this study assessed for the first time the potential mitigating impact of a DPP-IV inhibitor, vildagliptin (Vilda), on oxazolone (OXZ)-induced colitis in rats, targeting the role of PI3K/AKT/mTOR and AMPK/Nrf2 pathways. Thirty-two adult Albino rats were divided into four groups: control, Vilda (10 mg/kg/day orally), OXZ (300 µL of 5 % OXZ in 50 % aqueous ethanol solution introduced once into the colon via catheter), and Vilda+OXZ. Inflammatory cytokines (interleukin 13, tumor necrosis factor-α, interleukin 10), oxidative/endoplasmic reticulum stress markers (myeloperoxidase, reduced glutathione, catalase, CHOP), mitochondrial reactive oxygen species, adenosine triphosphate levels, and mitochondrial transmembrane potential were estimated. p-AMPK, p-AKT, beclin-1, and SQSTM1 levels were immunoassayed. Nrf2, PI3K, and mTOR expression levels were quantified using the real-time polymerase chain reaction. Furthermore, p-NF-ĸBp65 and LC3II immunoreactivity were evaluated. Vilda administration effectively ameliorated OXZ-induced colitis, as evidenced by the reduced Disease Activity Index, macroscopic colon damage score, colon weight/length ratio, ulcer index, and histopathological and electron microscopic changes in the colon tissues. Vilda treatment also counteracted OXZ-triggered inflammation, oxidative/endoplasmic reticulum stress, mitochondrial dysfunction, and enhanced autophagy in the colon. Vilda substantially suppressed PI3K/AKT/mTOR and activated the AMPK/Nrf2 pathway. Vilda has potent coloprotective and anti-ulcerogenic properties, primarily attributed to its antiinflammatory, antioxidant, and modulatory impact on mitochondrial dysfunction and autophagy activity. These effects were mostly mediated by suppressing PI3K/AKT/mTOR and activating AMPK/Nrf2 signaling cascades, suggesting a potential role of Vilda in UC therapy.

The Role of NRF2 in Trinucleotide Repeat Expansion Disorders

Trinucleotide repeat expansion disorders, a diverse group of neurodegenerative diseases, are caused by abnormal expansions within specific genes. These expansions trigger a cascade of cellular damage, including protein aggregation and abnormal RNA binding. A key contributor to this damage is oxidative stress, an imbalance of reactive oxygen species that harms cellular components. This review explores the interplay between oxidative stress and the NRF2 pathway in these disorders. NRF2 acts as the master regulator of the cellular antioxidant response, orchestrating the expression of enzymes that combat oxidative stress. Trinucleotide repeat expansion disorders often exhibit impaired NRF2 signaling, resulting in inadequate responses to excessive ROS production. NRF2 activation has been shown to upregulate antioxidative gene expression, effectively alleviating oxidative stress damage. NRF2 activators, such as omaveloxolone, vatiquinone, curcumin, sulforaphane, dimethyl fumarate, and resveratrol, demonstrate neuroprotective effects by reducing oxidative stress in experimental cell and animal models of these diseases. However, translating these findings into successful clinical applications requires further research. In this article, we review the literature supporting the role of NRF2 in the pathogenesis of these diseases and the potential therapeutics of NRF2 activators.

Restricting bioenergetic efficiency enhances longevity and mitochondrial redox capacity in Drosophila melanogaster

Mitochondria are essential for survival and as such, impairments in organelle homeostasis significantly accelerate age-related morbidity and mortality. Here, we determined the contribution of bioenergetic efficiency to life span and health span in Drosophila melanogaster utilizing the mitochondrial uncoupler BAM15. Life span was determined in flies fed a normal diet (ND) or high fat diet (HFD) supplemented with vehicle or BAM15. Locomotor function was determined by negative geotaxis assay in middle-aged flies fed vehicle or BAM15 under ND or HFD conditions. Redox capacity (high-resolution respirometry/fluorometry), citrate synthase (enzyme activity), mtDNA content (qPCR), gene expression (qPCR), and protein expression (western blot) were assessed in flight muscle homogenates of middle-aged flies fed vehicle or BAM15 ND. The molar ratio of H2O2 and O2 (H2O2:O2) in a defined respiratory state was calculated as a measure of redox balance. BAM15 extended life span by 9% on ND and 25% on HFD and improved locomotor activity by 125% on ND and 53% on HFD. Additionally, BAM15 enhanced oxidative phosphorylation capacity supported by pyruvate + malate, proline, and glycerol 3-phosphate. Concurrently, BAM15 enhanced the mitochondrial H2O2 production rate, reverse electron flow from mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) to Complex I, mGPDH, and Complex I without altering the H2O2:O2 ratio. BAM15 upregulated transcriptional signatures associated with mitochondrial function and fitness as well as antioxidant defense. BAM15-mediated restriction of bioenergetic efficiency prolongs life span and health span in Drosophila fed a ND or HFD. Improvements in life span and health span in ND were supported by synergistic enhancement of muscular redox capacity.

Mitochondrial-targeted curcumin inhibits T-cell activation via Nrf2 and inhibits graft-versus-host-disease in a mouse model

Anti-inflammatory and immune suppressive agents are required to moderate hyper-activation of lymphocytes under disease conditions or organ transplantation. However, selective disruption of mitochondrial redox has not been evaluated as a therapeutic strategy for suppression of T-cell-mediated pathologies. Using mitochondrial targeted curcumin (MitoC), we studied the effect of mitochondrial redox modulation on T-cell responses by flow cytometry, transmission electron microscopy, transcriptomics, and proteomics, and the role of Nrf2 was studied using Nrf2- /- mice. MitoC decreased mitochondrial TrxR activity, enhanced mitochondrial ROS (mROS) production, depleted mitochondrial glutathione, and suppressed activation-induced increase in mitochondrial biomass. This led to suppression of T-cell responses and metabolic reprogramming towards Treg differentiation. MitoC induced nuclear translocation and DNA binding of Nrf2, leading to upregulation of Nrf2-dependent genes and proteins. MitoC-mediated changes in mitochondrial redox and modulation of T-cell responses are abolished in Nrf2- /- mice. Restoration of mitochondrial thiols abrogated inhibition of T-cell responses. MitoC suppressed alloantigen-induced lymphoblast formation, inflammatory cytokines, morbidity, and mortality in acute graft-versus-host disease mice. Disruption of mitochondrial thiols but not mROS increase inculcates an Nrf2-dependent immune-suppressive disposition in T cells for the propitious treatment of graft-versus-host disease.

Homocysteine and Parkinson's disease

Homocysteine (Hcy) is an important metabolite in methionine metabolism. When the metabolic pathway of homocysteine is abnormal, it will accumulate in the body and eventually lead to hyperhomocysteinemia. In recent years, many studies have found that hyperhomocysteinemia is related to the occurrence and development of Parkinson's disease. This study reviews the roles of homocysteine in the pathogenesis of Parkinson's disease and illustrates the harmful effects of hyperhomocysteinemia on Parkinson's disease.

Role of Natural Antioxidants in Cancer

The oxidative stress defined as an event caused by an imbalance between production and accumulation of reactive oxygen species (ROS), which lead to a damage in the structure of proteins, lipids, and DNA. Therefore, the production of ROS may alter the normal physiological process by provoking damage to multiple cellular organelles and processes. Oxidative stress has been linked to heart disease, cancer, respiratory diseases, immune deficiency, stroke, Parkinson's disease, and other inflammatory or ischemic conditions. Antioxidants are substances that can prevent or slow damage to cells and tissues caused by ROS, unstable molecules that the body produces as a reaction to environmental and other pressures. The β-carotene, catechins, flavonoids, polyphenols, lycopene, lutein, selenium, vitamins A, C, D, E, and zeaxanthin are all common types of antioxidants and found in plant-based foods, especially fruits and vegetables. Each antioxidant has its own role and can interact with others to process and remove free radicals efficiently. Several studies have been conducted to investigate whether the use of dietary antioxidant supplements is associated with decreased risks of developing cancer in humans, mixed results were reported. For instance, daily use of supplement such as vitamin c, vitamin E, β-Carotene, and minerals such as selenium and zinc have shown its effectiveness by reducing the risk of developing prostate cancer among men and skin cancer among women.

Aging-related NOX4-Nrf2 redox imbalance increases susceptibility to cisplatin-induced acute kidney injury by regulating mitophagy

BACKGROUND

During aging, excessive ROS production in the kidneys leads to redox imbalance, which contributes to oxidative damage and impaired organ homeostasis. However, whether and how aging-related NOX4-Nrf2 redox imbalance increases susceptibility to cisplatin-induced acute kidney injury remain largely unknown.

METHODS

In this study, we used cisplatin-challenged aging mouse models and senescent HK-2 cells to investigate the effects and mechanisms of aging on susceptibility to cisplatin-induced acute kidney injury.

RESULTS

In vivo, we found that cisplatin stimulation caused more severe renal damage, oxidative stress, mitochondrial dysfunction and mitophagy impairment in aging mice than in young mice. Moreover, Nrf2 deficiency aggravated cisplatin-induced acute kidney injury by exacerbating NOX4-Nrf2 redox imbalance and defective mitophagy. In vitro experiments on D-gal-treated human renal tubular epithelial cells (HK-2) demonstrated that senescent renal epithelial cells exhibited increased susceptibility to cisplatin-induced apoptosis, NOX4-Nrf2 redox imbalance-mediated oxidative stress and defective mitophagy. Mechanistically, we found that knockdown of Nrf2 in HK2 cells resulted in increased ROS and aggravated mitophagy impairment, whereas these effects were reversed in NOX4-knockdown cells.

CONCLUSION

The present study indicates that NOX4-Nrf2 redox imbalance is critical for mitophagy deficiency in aged renal tubular epithelial cells and is a therapeutic target for alleviating cisplatin-induced acute kidney injury in elderly patients.

Lycium barbarum polysaccharides attenuate oxidative stress and mitochondrial toxicity induced by mixed plasticizers in HepG2 cells through activation of Nrf2

AIMS

In daily life, it is common for humans to be exposed to multiple phthalate esters (PAEs). However, there is limited research on the mechanisms and intervention of combined PAEs toxicity. This study aims to explore the cytotoxicity of combined PAEs and evaluate the potential of Lycium barbarum polysaccharides (LBP) in mitigating the aforementioned toxicity.

MAIN METHODS

LBP (62.5, 125 and 250 μg/mL) were applied to intervene HepG2 cells treated with DEHP and DBP mixtures (50, 100, 200, 400 and 800 μg/mL). Western Blot and different kits were mainly performed in our study.

KEY FINDINGS

DEHP and DBP mixtures suppressed the expression of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and activated MAPK pathway by increasing ROS. Combined DEHP and DBP exposure reduced ATP content and inhibited the mitochondrial biogenesis pathway in HepG2 cells through oxidative stress, which in turn caused cytotoxicity. LBP reduced oxidative stress and cell death induced by mixed plasticizers, upregulated Nrf2 levels and mitochondrial biogenesis pathway levels and inhibited MAPK pathway activation. Notably, after treating HepG2 cells with Nrf2-specific inhibitor (ML385, 0.5 μM), we found that the activation of Nrf2 played a crucial role on LBP intervention of DEHP and DBP induced HepG2 cytotoxicity.

SIGNIFICANCE

This study not only enhances our understanding of the toxicological effects caused by combined PAEs exposure, but also has significant implications in devising strategies to mitigate the toxicological consequences of combined exposure to exogenous chemicals through the investigation of the role of LBP.

Nrf2/PHB2 alleviates mitochondrial damage and protects against Staphylococcus aureus-induced acute lung injury

Staphylococcus aureus (SA) is a major cause of sepsis, leading to acute lung injury (ALI) characterized by inflammation and oxidative stress. However, the role of the Nrf2/PHB2 pathway in SA-induced ALI (SA-ALI) remains unclear. In this study, serum samples were collected from SA-sepsis patients, and a SA-ALI mouse model was established by grouping WT and Nrf2-/- mice after 6 h of intraperitoneal injection. A cell model simulating SA-ALI was developed using lipoteichoic acid (LTA) treatment. The results showed reduced serum Nrf2 levels in SA-sepsis patients, negatively correlated with the severity of ALI. In SA-ALI mice, downregulation of Nrf2 impaired mitochondrial function and exacerbated inflammation-induced ALI. Moreover, PHB2 translocation from mitochondria to the cytoplasm was observed in SA-ALI. The p-Nrf2/total-Nrf2 ratio increased in A549 cells with LTA concentration and treatment duration. Nrf2 overexpression in LTA-treated A549 cells elevated PHB2 content on the inner mitochondrial membrane, preserving genomic integrity, reducing oxidative stress, and inhibiting excessive mitochondrial division. Bioinformatic analysis and dual-luciferase reporter assay confirmed direct binding of Nrf2 to the PHB2 promoter, resulting in increased PHB2 expression. In conclusion, Nrf2 plays a role in alleviating SA-ALI by directly regulating PHB2 transcription and maintaining mitochondrial function in lung cells.

Biogenesis of Mitochondria in Multipotent Mesenchymal Stromal Cells in Patients with Acute Leukemia

In patients with acute leukemia, not only normal hematopoiesis, but also bone marrow stromal microenvironment is damaged. Multipotent mesenchymal stromal cells (MSC) are essential for the formation and function of the stromal microenvironment. Analysis of changes in MSC is important for the development of new approaches to leukemia therapy. The metabolism of mitochondria in MSC, relative content of mitochondrial DNA, and expression levels of genes encoding PGC-1α and Nrf2 proteins, important regulators of biogenesis, were studied using real-time PCR. Relative content of mitochondrial DNA does not change in MSC of acute leukemia patients at the onset of disease or in remission. Relative expression level of the gene encoding PGC-1α protein in MSC does not change significantly. However, relative expression level of the gene encoding Nrf2, an important antioxidant activity regulator, insignificantly decreases in patients at the onset of acute leukemia, and this decrease becomes significant upon reaching remission.

NRF2 is essential for adaptative browning of white adipocytes

White adipose tissue browning, defined by accelerated mitochondrial metabolism and biogenesis, is considered a promising mean to treat or prevent obesity-associated metabolic disturbances. We hypothesize that redox stress acutely leads to increased production of reactive oxygen species (ROS), which activate electrophile sensor nuclear factor erythroid 2-Related Factor 2 (NRF2) that over time results in an adaptive adipose tissue browning process. To test this, we have exploited adipocyte-specific NRF2 knockout mice and cultured adipocytes and analyzed time- and dose-dependent effect of NAC and lactate treatment on antioxidant expression and browning-like processes. We found that short-term antioxidant treatment with N-acetylcysteine (NAC) induced reductive stress as evident from increased intracellular NADH levels, increased ROS-production, reduced oxygen consumption rate (OCR), and increased NRF2 levels in white adipocytes. In contrast, and in line with our hypothesis, longer-term NAC treatment led to a NRF2-dependent browning response. Lactate treatment elicited similar effects as NAC, and mechanistically, these NRF2-dependent adipocyte browning responses in vitro were mediated by increased heme oxygenase-1 (HMOX1) activity. Moreover, this NRF2-HMOX1 axis was also important for β3-adrenergic receptor activation-induced adipose tissue browning in vivo. In conclusion, our findings show that administration of exogenous antioxidants can affect biological function not solely through ROS neutralization, but also through reductive stress. We also demonstrate that NRF2 is essential for white adipose tissue browning processes.

Sulforaphane Mitigates High-Fat Diet-Induced Obesity by Enhancing Mitochondrial Biogenesis in Skeletal Muscle via the HDAC8-PGC1α Axis

SCOPE

Histone deacetylases (HDACs) play a crucial role in the transcriptional regulation of various genes which can contribute to metabolic disorders. Although sulforaphane (SFN), a natural HDAC inhibitor, has been reported to alleviate obesity in humans and mice, the specific mechanisms and how HDACs contribute to SFN's anti-obesity effects remain unclear.

METHODS AND RESULTS

Oral administration of SFN in mice fed high-fat diet increases peroxisome proliferator activating receptor γ coactivator (PGC1α)-induced mitochondrial biogenesis in skeletal muscle. Among HDACs, SFN specifically inhibits HDAC8 activity. SFN enhances mitochondrial DNA and adenosine triphosphate (ATP) production in C2C12 myotubes, similar to the action of PCI34051, a synthetic HDAC8-specific inhibitor. These effects are mediated by increased expression of PGC1α via upregulation of cAMP response element binding (CREB, Ser133 ) phosphorylation and p53 (Lys379 ) acetylation. These SFN-induced effects are not observed in cells with a genetic deletion of HDAC8, suggesting the existence of a regulatory loop between HDAC8 and PGC1α in SFN's action.

CONCLUSION

SFN prevents obesity-related metabolic dysregulation by enhancing mitochondrial biogenesis and function via targeting the HDAC8-PGCα axis. These results suggest SFN as a beneficial anti-obesity agent providing new insight into the role of HDAC8 in the PGC1α-mediated mitochondrial biogenesis, which may be a novel and promising drug target for metabolic diseases.

Quantitative proteomic analyses uncover regulatory roles of Nrf2 in human endothelial cells

Nuclear factor erythroid 2-related factor 2 (Nrf2), a transcriptional regulator, is the predominant factor in modulating oxidative stress and other cellular signaling responses. Studies from our lab and others highlighted that activation of the Nrf2 pathway by small molecules improves endothelial function by suppressing oxidative and endoplasmic reticulum (ER) stress. However, the exact mechanisms by which Nrf2 elicits these effects are unknown. In the present study, we developed CRISPR/Cas9-mediated Nrf2 knocked-out human endothelial cells, and proteomic signature was studied using LC-MS/MS. We identified 723 unique proteins, of which 361 proteins were found to be differentially regulated and further screened in the Nrf2ome online database, where we identified a highly interconnected signaling network in which 70 proteins directly interact with Nrf2. These proteins were found to regulate some key cellular and metabolic processes in the regulation actin cytoskeleton, ER stress, angiogenesis, inflammation, Hippo signaling pathway, and epidermal growth factor/fibroblast growth factor (EGF/FGF) signaling pathway. Our findings suggest the role of Nrf2 in maintaining endothelium integrity and its relationship with the crucial cellular processes which help develop novel therapeutics against endothelial dysfunction and its associated complications.

Oxidative stress and inflammation induced by air pollution-derived PM2.5 persist in the lungs of mice after cessation of their sub-chronic exposure

More than 7 million early deaths/year are attributable to air pollution. Current health concerns are especially focused on air pollution-derived particulate matter (PM). Although oxidative stress-induced airway inflammation is one of the main adverse outcome pathways triggered by air pollution-derived PM, the persistence of both these underlying mechanisms, even after exposure cessation, remained poorly studied. In this study, A/JOlaHsd mice were also exposed acutely (24 h) or sub-chronically (4 weeks), with or without a recovery period (12 weeks), to two urban PM2.5 samples collected during contrasting seasons (i.e., autumn/winter, AW or spring/summer, SS). The distinct intrinsic oxidative potentials (OPs) of AW and SS PM2.5, as evaluated in acellular conditions, were closely related to their respective physicochemical characteristics and their respective ability to really generate ROS over-production in the mouse lungs. Despite the early activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) cell signaling pathway by AW and, in a lesser degree, SS PM2.5, in the murine lungs after acute and sub-chronic exposures, the critical redox homeostasis was not restored, even after the exposure cessation. Accordingly, an inflammatory response was reported through the activation of the nuclear factor-kappa B (NF-κB) cell signaling pathway activation, the secretion of cytokines, and the recruitment of inflammatory cells, in the murine lungs after the acute and sub-chronic exposures to AW and, in a lesser extent, to SS PM2.5, which persisted after the recovery period. Taken together, these original results provided, for the first time, new relevant insights that air pollution-derived PM2.5, with relatively high intrinsic OPs, induced oxidative stress and inflammation, which persisted admittedly at a lower level in the lungs after the exposure cessation, thereby contributing to the occurrence of molecular and cellular adverse events leading to the development and/or exacerbation of future chronic inflammatory lung diseases and even cancers.

A Review of the Potential of Nuclear Factor [Erythroid-Derived 2]-like 2 Activation in Autoimmune Diseases

An autoimmune disease is the consequence of the immune system attacking healthy cells, tissues, and organs by mistake instead of protecting them. Inflammation and oxidative stress (OS) are well-recognized processes occurring in association with acute or chronic impairment of cell homeostasis. The transcription factor Nrf2 (nuclear factor [erythroid-derived 2]-like 2) is of major importance as the defense instrument against OS and alters anti-inflammatory activities related to different pathological states. Researchers have described Nrf2 as a significant regulator of innate immunity. Growing indications suggest that the Nrf2 signaling pathway is deregulated in numerous diseases, including autoimmune disorders. The advantageous outcome of the pharmacological activation of Nrf2 is an essential part of Nrf2-based chemoprevention and intervention in other chronic illnesses, such as neurodegeneration, cardiovascular disease, autoimmune diseases, and chronic kidney and liver disease. Nevertheless, a growing number of investigations have indicated that Nrf2 is already elevated in specific cancer and disease steps, suggesting that the pharmacological agents developed to mitigate the potentially destructive or transformative results associated with the protracted activation of Nrf2 should also be evaluated. The activators of Nrf2 have revealed an improvement in the progress of OS-associated diseases, resulting in immunoregulatory and anti-inflammatory activities; by contrast, the depletion of Nrf2 worsens disease progression. These data strengthen the growing attention to the biological properties of Nrf2 and its possible healing power on diseases. The evidence supporting a correlation between Nrf2 signaling and the most common autoimmune diseases is reviewed here. We focus on the aspects related to the possible effect of Nrf2 activation in ameliorating pathologic conditions based on the role of this regulator of antioxidant genes in the control of inflammation and OS, which are processes related to the progression of autoimmune diseases. Finally, the possibility of Nrf2 activation as a new drug development strategy to target pathogenesis is proposed.

Differential genomic effects of four nano-sized and one micro-sized CeO2 particles on HepG2 cells

The objective of this research was to perform a genomics study of five cerium oxide particles, 4 nano and one micrometer-sized particles which have been studied previously by our group with respect to cytotoxicity, biochemistry and metabolomics. Human liver carcinoma HepG2 cells were exposed to between 0.3 to 300 ug/ml of CeO2 particles for 72 hours and then total RNA was harvested. Fatty acid accumulation was observed with W4, X5, Z7 and less with Q but not Y6. The gene expression changes in the fatty acid metabolism genes correlated the fatty acid accumulation we detected in the prior metabolomics study for the CeO2 particles named W4, Y6, Z7 and Q, but not for X5. In particular, the observed genomics effects on fatty acid uptake and fatty acid oxidation offer a possible explanation of why many CeO2 particles increase cellular free fatty acid concentrations in HepG2 cells. The major genomic changes observed in this study were sirtuin, ubiquitination signaling pathways, NRF2-mediated stress response and mitochondrial dysfunction. The sirtuin pathway was affected by many CeO2 particle treatments. Sirtuin signaling itself is sensitive to oxidative stress state of the cells and may be an important contributor in CeO2 particle induced fatty acid accumulation. Ubiquitination pathway regulates many protein functions in the cells, including sirtuin signaling, NRF2 mediated stress, and mitochondrial dysfunction pathways. NRF2-mediated stress response and mitochondrial were reported to be altered in many nanoparticles treated cells. All these pathways may contribute to the fatty acid accumulation in the CeO2 particle treated cells.