Sulforaphane reactivates cellular antioxidant defense by inducing Nrf2/ARE/Prdx6 activity during aging and oxidative stress

Protective effects of sulforaphane against toxic substances and contaminants: A systematic review

BACKGROUND

Sulforaphane (SFN) is a dietary isothiocyanate, derived from glucoraphanin, present in cruciferous vegetables belonging to the Brassica genus. It is a biologically active phytochemical that acts as a nuclear factor erythroid 2-related factor 2 (Nrf2) inducer. Thus, it has been reported to have multiple protective functions including anticancer responses and protection against a toxic agent's action.

PURPOSE

The present work systematically reviewed and synthesised the protective properties of sulforaphane against a toxic agent. This review reveals the mechanism of the action of SFN in each organ or system.

METHODS

The PRISMA guideline was followed in this sequence: researched literature, organised retrieved documents, abstracted relevant information, assessed study quality and bias, synthesised data, and prepared a comprehensive report. Searches were conducted on Science Direct and PubMed using the keywords "Sulforaphane" AND ("protective effects" OR "protection against").

RESULTS

Reports showed that liver and the nervous system are the target organs on which attention was focused, and this might be due to the key role of oxidative stress in liver and neurodegenerative diseases. However, protective activities have also been demonstrated in the lungs, heart, immune system, kidneys, and endocrine system. SFN exerts its protective effects by activating the Nrf2 pathway, which enhances antioxidant defenses and reduces oxidative stress. It also suppresses inflammation by decreasing interleukin production. Moreover, SFN inhibits apoptosis by preventing caspase 3 cleavage and increasing Bcl2 levels. Overall, SFN demonstrates multifaceted mechanisms to counteract the adverse effects of toxic agents.

CONCLUSION

SFN has potential clinical applications as a chemoprotective agent. Nevertheless, more studies are necessary to set the safe doses of SFN in humans.

DNA methylation as an epigenetic mechanism in the regulation of LEDGF expression and biological response in aging and oxidative stress

The physiological quantum of stress-inducible transcriptional protein, Lens Epithelium-Derived Growth Factor (LEDGF), is vital for the maintenance of cellular physiology. Erratic epigenetic reprogramming in response to oxidative stress or with advancing age is found to be a major cause in the gene silencing, leading to pathobiologies. Using aging human (h) eye lens/lens epithelial cells (LECs) coupled with redox-active Peroxiredoxin 6 (Prdx6)-deficient (Prdx6-/-) mLECs as model systems, herein, we showed that in aging/oxidative stress, the human LEDGF gene was regulated by unique methylation patterns of CGs nucleotides within and around the Sp1 binding site(s) of CpG island of the LEDGF promoter (-170 to -27nts). The process caused the repression of LEDGF and its target, Hsp27, resulting in reactive oxygen species (ROS) amplification and cellular insults. This phenomenon was opposed to the unmethylated promoter in LECs. Clinically, we observed that the loss of LEDGF in the Prdx6-/- mLECs or aging lenses/LECs, correlating with increased expression of DNMT1, DNMT3a, and DNMT3b along with the methyl CpG binding protein 2 (MeCP2). Upon oxidative stress, the expression of these molecules was increased with the dramatic reduction in LEDGF expression. While demethylating agent, 5-Aza deoxycytidine (5-AzaC) transposed the aberrant methylation status, and revived LEDGF and Hsp27 expression. Mechanistically, the chloramphenicol acetyltransferase (CAT) reporter gene driven by the LEDGF promoter (-170/ + 35) and ChIP assays uncovered that 5-AzaC acted on GC/Sp1 sites to release LEDGF transcription. The data argued, for the first time, that de novo methylation of CGs around and within Sp1 sites of the CpG island directly disrupted Sp1 activity, which ensued in LEDGF repression and its biological functions. The findings should improve our understanding of cellular insults-associated with aberrant DNMTs-mediated LEDGF's activity, and can offer strategies for therapeutic intervention to halt aging/oxidative stress-induced abnormalities.

A novel rat model of cerebral small vessel disease based on vascular risk factors of hypertension, aging, and cerebral hypoperfusion

Cerebral small vessel disease (CSVD) is a major cause of vascular cognitive impairment and functional loss in elderly patients. Progressive remodeling of cerebral microvessels due to arterial hypertension or other vascular risk factors, such as aging, can cause dementia or stroke. Typical imaging characteristics of CSVD include cerebral microbleeds (CMB), brain atrophy, small subcortical infarctions, white matter hyperintensities (WMH), and enlarged perivascular spaces (EPVS). Nevertheless, no animal models that reflect all the different aspects of CSVD have been identified. Here, we generated a new CSVD animal model using D-galactose (D-gal) combined with cerebral hypoperfusion in spontaneously hypertensive rats (SHR), which showed all the hallmark pathological features of CSVD and was based on vascular risk factors. SHR were hypodermically injected with D-gal (400 mg/kg/d) and underwent modified microcoil bilateral common carotid artery stenosis surgery. Subsequently, neurological assessments and behavioral tests were performed, followed by vascular ultrasonography, electron microscopy, flow cytometry, and histological analyses. Our rat model showed multiple cerebrovascular pathologies, such as CMB, brain atrophy, subcortical small infarction, WMH, and EPVS, as well as the underlying causes of CSVD pathology, including oxidative stress injury, decreased cerebral blood flow, structural and functional damage to endothelial cells, increased blood-brain barrier permeability, and inflammation. The use of this animal model will help identify new therapeutic targets and subsequently aid the development and testing of novel therapeutic interventions. Main process of the study: Firstly, we screened for optimal conditions for mimicking aging by injecting D-gal into rats for 4 and 8 weeks. Subsequently, we performed modified microcoil BCAS intervention for 4 and 8 weeks in rats to screen for optimal hypoperfusion conditions. Finally, based on these results, we combined D-gal for 8 weeks and modified microcoil BCAS for 4 weeks to explore the changes in SHR.

Alleviation of microcystin-leucine arginine -induced hepatotoxicity: An updated overview

OBJECTIVES

Contamination of surface waters is a major health threat for all living creatures. Some types of blue-green algae that naturally occur in fresh water, are able to produce various toxins, like Microcystins (MCs). Microcystin-leucine arginine (MC-LR) produced by Microcystis aeruginosa is the most toxic and abundant isoforms of MCs, and it causes hepatotoxicity. The present article reviews preclinical experiments examined different treatments, including herbal derivatives, dietary supplements and drugs against MC-LR hepatotoxicity.

METHODS

We searched scientific databases Web of Science, Embase, Medline (PubMed), Scopus, and Google Scholar using relevant keywords to find suitable studies until November 2023.

RESULTS

MC-LR through Organic anion transporting polypeptide superfamily transporters (OATPs) penetrates and accumulates in hepatocytes, and it inhibits protein phosphatases (PP1 and PP2A). Consequently, MC-LR disturbs many signaling pathways and induces oxidative stress thus damages cellular macromolecules. Some protective agents, especially plants rich in flavonoids, and natural supplements, as well as chemoprotectants were shown to diminish MC-LR hepatotoxicity.

CONCLUSION

The reviewed agents through blocking the OATP transporters (nontoxic nostocyclopeptide-M1, captopril, and naringin), then inhibition of MC-LR uptake (naringin, rifampin, cyclosporin-A, silymarin and captopril), and finally at restoration of PPAse activity (silybin, quercetin, morin, naringin, rifampin, captopril, azo dyes) exert hepatoprotective effect against MC-LR.

Enzyme-Responsive Fluorescent Labeling Strategy for In Vivo Imaging of Gut Bacteria

Myrosinase (Myr), as a unique β-thioglucosidase enzyme capable of converting natural and gut bacterial metabolite glucosinolates into bioactive agents, has recently attracted a great deal of attention because of its essential functions in exerting homeostasis dynamics and promoting human health. Such nutraceutical and biomedical significance demands unique and reliable strategies for specific identification of Myr enzymes of gut bacterial origin in living systems, whereas the dearth of methods for bacterial Myr detection and visualization remains a challenging concern. Herein, we present a series of unique molecular probes for specific identification and imaging of Myr-expressing gut bacterial strains. Typically, an artificial glucosinolate with an azide group in aglycone was synthesized and sequentially linked with the probe moieties of versatile channels through simple click conjugation. Upon gut bacterial enzymatic cleavage, the as-prepared probe molecules could be converted into reactive isothiocyanate forms, which can further act as reactive electrophiles for the covalent labeling of gut bacteria, thus realizing their localized fluorescent imaging within a wide range of wavelength channels in live bacterial strains and animal models. Overall, our proposed method presents a novel technology for selective gut bacterial Myr enzyme labeling in vitro and in vivo. We envision that such a rational probe design would serve as a promising solution for chemoprevention assessment, microflora metabolic mechanistic study, and gut bacterium-mediated physiopathological exploration.

Unveiling the Significance of Peroxiredoxin 6 in Central Nervous System Disorders

Peroxiredoxin 6 (Prdx6), a unique 1-Cys member of the peroxiredoxin family, exhibits peroxidase activity, phospholipase activity, and lysophosphatidylcholine acyltransferase (LPCAT) activity. Prdx6 has been known to be an important enzyme for the maintenance of lipid peroxidation repair, cellular metabolism, inflammatory signaling, and antioxidant damage. Growing research has demonstrated that the altered activity of this enzyme is linked with various pathological processes including central nervous system (CNS) disorders. This review discusses the distinctive structure, enzyme activity, and function of Prdx6 in different CNS disorders, as well as emphasizing the significance of Prdx6 in neurological disorders.

Exploring the Phytochemical Diversity and Antioxidant Potential of the Vietnamese Smilax glabra Roxb: Insights from UPLC-QTOF-MS/MS and Zebrafish Model Studies

Research on natural products is growing due to their potential health benefits and medicinal properties. Despite regional variations in phytochemical composition and bioactivity, Smilax glabra Roxb (SGB) has attracted the interest of researchers. Scientists are particularly interested in the Vietnamese SGB variant, which is influenced by biological and environmental factors. Despite geographical differences in phytochemical makeup and bioactivities, SGB remains a fascinating subject in traditional herbal medicine. Using ultra-performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS), the phytochemicals in Vietnamese SGB extracts were investigated. This study revealed a wide range of phytochemical compounds, including flavonoids, terpenoids, glycosides, alkaloids, organic acids, phenolics, and steroids. Furthermore, utilizing zebrafish as a model organism, we discovered that these extracts have the surprising ability to greatly improve the survival rate of zebrafish larvae exposed to oxidative stress caused by arsenite (NaAsO2) and hydrogen peroxide (H2O2). Notably, our discoveries suggest the occurrence of new antioxidative pathways in addition to the kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, expanding the understanding of the antioxidant properties and potential therapeutic uses of these plants. To summarize, our research findings shed light on the phytochemical composition of Vietnamese SGB, revealing its potential as a natural antioxidant and encouraging further exploration of its underlying mechanisms for future innovative antioxidant therapies.

Sulforaphane protects from kidney damage during the release of unilateral ureteral obstruction (RUUO) by activating nuclear factor erythroid 2-related factor 2 (Nrf2): Role of antioxidant, anti-inflammatory, and antiapoptotic mechanisms

Releasing unilateral ureteral obstruction (RUUO) is the gold standard for decreasing renal damage induced during unilateral ureteral obstruction (UUO); however, the complete recovery after RUUO depends on factors such as the time and severity of obstruction and kidney contralateral compensatory mechanisms. Interestingly, previous studies have shown that kidney damage markers such as oxidative stress, inflammation, and apoptosis are present and even increase after removal obstruction. To date, previous therapeutic strategies have been used to potentiate the recovery of renal function after RUUO; however, the mechanisms involving renal damage reduction are poorly described and sometimes focus on the recovery of renal functionality. Furthermore, using natural antioxidants has not been completely studied in the RUUO model. In this study, we selected sulforaphane (SFN) because it activates the nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that induces an antioxidant response, decreasing oxidative stress and inflammation, preventing apoptosis. Thus, we pre-administrated SFN on the second day after UUO until day five, where we released the obstruction on the three days after UUO. Then, we assessed oxidative stress, inflammation, and apoptosis markers. Interestingly, we found that SFN administration in the RUUO model activated Nrf2, inducing its translocation to the nucleus to activate its target proteins. Thus, the Nrf2 activation upregulated glutathione (GSH) content and the antioxidant enzymes catalase, glutathione peroxidase (GPx), and glutathione reductase (GR), which reduced the oxidative stress markers. Moreover, the improvement of antioxidant response by SFN restored S-glutathionylation in the mitochondrial fraction. Activated Nrf2 also reduced inflammation by lessening the nucleotide-binding domain-like receptor family pyrin domain containing 3 and interleukin 1β (IL-1β) production. Reducing oxidative stress and inflammation prevented apoptosis by avoiding caspase 3 cleavage and increasing B-cell lymphoma 2 (Bcl2) levels. Taken together, the obtained results in our study showed that the upregulation of Nrf2 by SFN decreases oxidative stress, preventing inflammation and apoptosis cell death during the release of UUO.

Comprehensive and critical view on the anti-inflammatory and immunomodulatory role of natural phenolic antioxidants

The immune response encompasses innate and adaptive immunity, each with distinct and specific activities. The innate immune system is constituted by phagocytic cells, macrophages, monocytes and neutrophils, the cascade system, and different classes of receptors such as toll-like receptors that are exploited by the innate immune cells. The adaptive immune system is antigen-specific, encompassing memory lymphocytes and the corresponding specific receptors. Inflammation is understood as an activation of different signaling pathways such as toll-like receptors or nuclear factor kappa-light-chain-enhancer of activated B cells, with an increase in nitric oxide, inflammatory cytokines and chemokines. Increased oxidative stress has been identified as main source of chronic inflammation. Phenolic antioxidants modulate the activities of lymphocytes and macrophages by impacting cytokines and nitric oxide release, exerting anti-inflammatory effect. The nuclear-factor kappa-light-chain-enhancer of activated B cells signaling pathway and the mitogen-activated protein kinase pathway are targeted, alongside an increase in nuclear factor erythroid 2-related factor mediated antioxidant response, triggering the activity of antioxidant enzymes. The inhibitive potential on phospholipase A2, cyclooxygenase and lipoxygenase in the arachidonic acid pathway, and the subsequent reduction in prostaglandin and leukotriene generation, reveals the potential of phenolics as inflammation antagonists. The immunomodulative potential encompasses the capacity to interfere with proinflammatory cytokine synthesis and with the expression of the corresponding genes. A diet rich in antioxidants can result in prevention of inflammation-related pathologies. More investigations are necessary to establish the role of these antioxidants in therapy. The appropriate delivery system and the prooxidant effects exhibited at large doses, or in the presence of heavy metal cations should be regarded.

Plant sources, extraction techniques, analytical methods, bioactivity, and bioavailability of sulforaphane: a review

Sulforaphane (SFN) is an isothiocyanate commonly found in cruciferous vegetables. It is formed via the enzymatic hydrolysis of glucoraphanin by myrosinase. SFN exerts various biological effects, including anti-cancer, anti-oxidation, anti-obesity, and anti-inflammatory effects, and is widely used in functional foods and clinical medicine. However, the structure of SFN is unstable and easily degradable, and its production is easily affected by temperature, pH, and enzyme activity, which limit its application. Hence, several studies are investigating its physicochemical properties, stability, and biological activity to identify methods to increase its content. This article provides a comprehensive review of the plant sources, extraction and analysis techniques, in vitro and in vivo biological activities, and bioavailability of SFN. This article highlights the importance and provides a reference for the research and application of SFN in the future.

Polysaccharides from Polygonatum cyrtonema Hua prevent post-traumatic stress disorder behaviors in mice: Mechanisms from the perspective of synaptic injury, oxidative stress, and neuroinflammation

ETHNOPHARMACOLOGICAL RELEVANCE

According to traditional Chinese medicine (TCM) theory, post-traumatic stress disorder (PTSD) is a kind of depression syndrome, and its occurrence is related to deficiencies of the heart and kidney. Polygonatum cyrtonema Hua replenishes Qi and blood and tonifies the five zang organs, so it is widely used in TCM as a prescription for the treatment of depression syndrome. The polysaccharides in P. cyrtonema Hua (PSP) are the main active components of the herb, but the effects of PSP on PTSD and the mechanisms remain unclear.

AIM OF THE STUDY

To investigate the preventive effect of PSP on PTSD-like behaviors and to determine the mechanisms.

METHODS

We used behavioral tests to evaluate PTSD-like behaviors in mice. Synaptic changes were assessed by transmission electron microscopy. Hematoxylin-eosin staining was used to assess pathological changes to the hippocampus, and immunofluorescence staining was used to observe changes in astrocytes. Serum corticosterone (CORT), cytokine, and hippocampal oxidation-related indicator levels were evaluated by ELISA. We detected the expression levels of synaptic, oxidative, and inflammation-related proteins in the hippocampus by western blotting.

RESULTS

Single prolonged stress (SPS)-modeled mice exhibited significant PTSD-like phenotypes, including increased fear memory acquisition and anxiety-like behaviors. These behavioral changes were prevented by PSP administration. Compared to controls, SPS modeling increased serum CORT, cytokine, and hippocampal malondialdehyde levels; decreased superoxide dismutase activity; and caused losses in pyramidal neurons, astrocytes, and synapses in the CA1 region. At the molecular level, the expression of brain-derived neurotrophic factor, postsynaptic density protein 95, nuclear factor erythroid 2-related factor 2 (Nrf2), phospho-tyrosine kinase receptor B, activity-regulated cytoskeleton-associated protein, heme oxygenase-1 (HO-1), and GluA1 decreased in SPS mice compared with the control group, while the expression of NOD-like receptor protein 3 (NLRP3), GluN2B, and apoptosis-associated speck-like protein increased in SPS mice. Treatment with PSP counteracted these abnormal changes. Importantly, ML385, an Nrf2 inhibitor, blocked PSP's ability to ameliorate PTSD behaviors and abnormal protein expression. The NLRP3 inhibitor MCC950 reduced the PTSD-like behaviors and normalized protein expression in SPS mice.

CONCLUSION

PSP prevents SPS-induced PTSD-like behaviors and synaptic damage by regulating oxidative stress and NLRP3-mediated inflammation, probably in an Nrf2/HO-1 signaling pathway-dependent manner.

Sulforaphane Supplementation Did Not Modulate NRF2 and NF-kB mRNA Expressions in Hemodialysis Patients

BACKGROUND

Patients with chronic kidney disease (CKD) have reduced expression of erythroid nuclear factor-related factor 2 (NRF2) and increased nuclear factor κB (NF-κB). "Food as medicine" has been proposed as an adjuvant therapeutic alternative in modulating these factors. No studies have investigated the effects of sulforaphane (SFN) in cruciferous vegetables on the expression of these genes in patients with CKD.

OBJECTIVE

The study aimed to evaluate the effects of SFN on the expression of NRF2 and NF-κB in patients on hemodialysis (HD).

DESIGN AND METHODS

A randomized, double-blind, crossover study was performed on 30 patients on regular HD. Fourteen patients were randomly allocated to the intervention group (1 sachet/day of 2.5 g containing 1% SFN extract with 0.5% myrosinase) and 16 patients to the placebo group (1 sachet/day of 2.5 g containing corn starch colored with chlorophyll) for 2 months. After a washout period of 2 months, the groups were switched. NRF2 and NF-κB mRNA expression was evaluated by real-time quantitative polymerase chain reaction, and tumor necrosis factor alpha and interleukin-6 levels were quantified by enzyme-linked immunosorbent assay. Malondialdehyde was evaluated as a marker of lipid peroxidation.

RESULTS

Twenty-five patients (17 women, 55 [interquartile range = 19] years and 55 [interquartile range = 74] months on HD) completed the study. There was no significant difference concerning the expression of mRNA NRF2 (P = .915) and mRNA NF-κB (P = .806) after supplementation with SFN. There was no difference in pro-inflammatory and oxidative stress biomarkers.

CONCLUSION

150 μmol of SFN for 2 months had no antioxidant and anti-inflammatory effect in patients with CKD undergoing HD.

Open-Label Sulforaphane Trial in FMR1 Premutation Carriers with Fragile-X-Associated Tremor and Ataxia Syndrome (FXTAS)

Fragile X (FMR1) premutation is a common mutation that affects about 1 in 200 females and 1 in 450 males and can lead to the development of fragile-X-associated tremor/ataxia syndrome (FXTAS). Although there is no targeted, proven treatment for FXTAS, research suggests that sulforaphane, an antioxidant present in cruciferous vegetables, can enhance mitochondrial function and maintain redox balance in the dermal fibroblasts of individuals with FXTAS, potentially leading to improved cognitive function. In a 24-week open-label trial involving 15 adults aged 60-88 with FXTAS, 11 participants successfully completed the study, demonstrating the safety and tolerability of sulforaphane. Clinical outcomes and biomarkers were measured to elucidate the effects of sulforaphane. While there were nominal improvements in multiple clinical measures, they were not significantly different after correction for multiple comparisons. PBMC energetic measures showed that the level of citrate synthase was higher after sulforaphane treatment, resulting in lower ATP production. The ratio of complex I to complex II showed positive correlations with the MoCA and BDS scores. Several mitochondrial biomarkers showed increased activity and quantity and were correlated with clinical improvements.

The Anti-Inflammatory Effects of Broccoli (Brassica oleracea L. var. italica) Sprout Extract in RAW 264.7 Macrophages and a Lipopolysaccharide-Induced Liver Injury Model

Brassica oleracea var. italica (broccoli), a member of the cabbage family, is abundant with many nutrients, including vitamins, potassium, fiber, minerals, and phytochemicals. Consequently, it has been used as a functional food additive to reduce oxidative stress and inflammatory responses. In the current study, the effects of sulforaphane-rich broccoli sprout extract (BSE) on the inflammatory response were investigated in vitro and in vivo. Comparative high-performance liquid chromatography analysis of sulforaphane content from different extracts revealed that 70% ethanolic BSE contained more sulforaphane than the other extracts. qPCR and enzyme immunoassay analyses revealed that BSE markedly reduced the expression of proinflammatory cytokines and mediators, including cyclooxygenase 2, interleukin (IL)-1β, IL-6, IL-1, inducible nitric oxide synthase (iNOS), and tumor necrosis factor-α (TNF-α), in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Pretreatment with BSE improved the survival rate and suppressed alanine aminotransferase and aspartate aminotransferase expression in LPS-induced endotoxemic mice, while proinflammatory cytokines such as IL-1β, TNF-α, IL-6, cyclooxygenase-2, and iNOS decreased dramatically in the LPS-induced liver injury model via BSE treatment. Additionally, F4/80 immunostaining showed that BSE suppressed hepatic macrophage infiltration in the liver after lipopolysaccharide injection. In conclusion, BSE may be a potential nutraceutical for preventing and regulating excessive immune responses in inflammatory disease.

Peroxiredoxins in erythrocytes: far beyond the antioxidant role

The red blood cells (RBCs) are essential to transport oxygen (O2) and nutrients throughout the human body. Changes in the structure or functioning of the erythrocytes can lead to several deficiencies, such as hemolytic anemias, in which an increase in reactive oxidative species generation is involved in the pathophysiological process, playing a significant role in the severity of several clinical manifestations. There are important lines of defense against the damage caused by oxidizing molecules. Among the antioxidant molecules, the enzyme peroxiredoxin (Prx) has the higher decomposition power of hydrogen peroxide, especially in RBCs, standing out because of its abundance. This review aimed to present the recent findings that broke some paradigms regarding the three isoforms of Prxs found in RBC (Prx1, Prx2, and Prx6), showing that in addition to their antioxidant activity, these enzymes may have supplementary roles in transducing peroxide signals, as molecular chaperones, protecting from membrane damage, and maintenance of iron homeostasis, thus contributing to the overall survival of human RBCs, roles that seen to be disrupted in hemolytic anemia conditions.

Nrf2 signaling pathway: current status and potential therapeutic targetable role in human cancers

Cancer is a borderless global health challenge that continues to threaten human health. Studies have found that oxidative stress (OS) is often associated with the etiology of many diseases, especially the aging process and cancer. Involved in the OS reaction as a key transcription factor, Nrf2 is a pivotal regulator of cellular redox state and detoxification. Nrf2 can prevent oxidative damage by regulating gene expression with antioxidant response elements (ARE) to promote the antioxidant response process. OS is generated with an imbalance in the redox state and promotes the accumulation of mutations and genome instability, thus associated with the establishment and development of different cancers. Nrf2 activation regulates a plethora of processes inducing cellular proliferation, differentiation and death, and is strongly associated with OS-mediated cancer. What's more, Nrf2 activation is also involved in anti-inflammatory effects and metabolic disorders, neurodegenerative diseases, and multidrug resistance. Nrf2 is highly expressed in multiple human body parts of digestive system, respiratory system, reproductive system and nervous system. In oncology research, Nrf2 has emerged as a promising therapeutic target. Therefore, certain natural compounds and drugs can exert anti-cancer effects through the Nrf2 signaling pathway, and blocking the Nrf2 signaling pathway can reduce some types of tumor recurrence rates and increase sensitivity to chemotherapy. However, Nrf2's dual role and controversial impact in cancer are inevitable consideration factors when treating Nrf2 as a therapeutic target. In this review, we summarized the current state of biological characteristics of Nrf2 and its dual role and development mechanism in different tumor cells, discussed Keap1/Nrf2/ARE signaling pathway and its downstream genes, elaborated the expression of related signaling pathways such as AMPK/mTOR and NF-κB. Besides, the main mechanism of Nrf2 as a cancer therapeutic target and the therapeutic strategies using Nrf2 inhibitors or activators, as well as the possible positive and negative effects of Nrf2 activation were also reviewed. It can be concluded that Nrf2 is related to OS and serves as an important factor in cancer formation and development, thus provides a basis for targeted therapy in human cancers.

Effects of Sulforaphane on SARS‑CoV‑2 infection and NF‑κB dependent expression of genes involved in the COVID‑19 'cytokine storm'

Since its spread at the beginning of 2020, the coronavirus disease 2019 (COVID‑19) pandemic represents one of the major health problems. Despite the approval, testing, and worldwide distribution of anti‑severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) vaccines, the development of specific antiviral agents targeting the SARS‑CoV‑2 life cycle with high efficiency, and/or interfering with the associated 'cytokine storm', is highly required. A recent study, conducted by the authors' group indicated that sulforaphane (SFN) inhibits the expression of IL‑6 and IL‑8 genes induced by the treatment of IB3‑1 bronchial cells with a recombinant spike protein of SARS‑CoV‑2. In the present study, the ability of SFN to inhibit SARS‑CoV‑2 replication and the expression of pro‑inflammatory genes encoding proteins of the COVID‑19 'cytokine storm' was evaluated. SARS‑CoV‑2 replication was assessed in bronchial epithelial Calu‑3 cells. Moreover, SARS‑CoV‑2 replication and expression of pro‑inflammatory genes was evaluated by reverse transcription quantitative droplet digital PCR. The effects on the expression levels of NF‑κB were assessed by western blotting. Molecular dynamics simulations of NF‑kB/SFN interactions were conducted with Gromacs 2021.1 software under the Martini 2 CG force field. Computational studies indicated that i) SFN was stably bound with the NF‑κB monomer; ii) a ternary NF‑kB/SFN/DNA complex was formed; iii) the SFN interacted with both the protein and the nucleic acid molecules modifying the binding mode of the latter, and impairing the full interaction between the NF‑κB protein and the DNA molecule. This finally stabilized the inactive complex. Molecular studies demonstrated that SFN i) inhibits the SARS‑CoV‑2 replication in infected Calu‑3 cells, decreasing the production of the N‑protein coding RNA sequences, ii) decreased NF‑κB content in SARS‑CoV‑2 infected cells and inhibited the expression of NF‑kB‑dependent IL‑1β and IL‑8 gene expression. The data obtained in the present study demonstrated inhibitory effects of SFN on the SARS‑CoV‑2 life cycle and on the expression levels of the pro‑inflammatory genes, sustaining the possible use of SFN in the management of patients with COVID‑19.

Neural crest cells and fetal alcohol spectrum disorders: Mechanisms and potential targets for prevention

Fetal alcohol spectrum disorders (FASD) are a group of preventable and nongenetic birth defects caused by prenatal alcohol exposure that can result in a range of cognitive, behavioral, emotional, and functioning deficits, as well as craniofacial dysmorphology and other congenital defects. During embryonic development, neural crest cells (NCCs) play a critical role in giving rise to many cell types in the developing embryos, including those in the peripheral nervous system and craniofacial structures. Ethanol exposure during this critical period can have detrimental effects on NCC induction, migration, differentiation, and survival, leading to a broad range of structural and functional abnormalities observed in individuals with FASD. This review article provides an overview of the current knowledge on the detrimental effects of ethanol on NCC induction, migration, differentiation, and survival. The article also examines the molecular mechanisms involved in ethanol-induced NCC dysfunction, such as oxidative stress, altered gene expression, apoptosis, epigenetic modifications, and other signaling pathways. Furthermore, the review highlights potential therapeutic strategies for preventing or mitigating the detrimental effects of ethanol on NCCs and reducing the risk of FASD. Overall, this article offers a comprehensive overview of the current understanding of the impact of ethanol on NCCs and its role in FASD, shedding light on potential avenues for future research and intervention.

Sulforaphane protects microvascular endothelial cells in lower limb ischemia/reperfusion injury mice

Background: Microvascular damage is a key pathological factor in acute lower limb ischemia/reperfusion (I/R) injury. Current evidence suggests that sulforaphane (SFN) protects tissue from I/R injury. However, the role of SFN in acute lower limb I/R injury remains elusive. This study aimed to investigate the role and potential mechanism of SFN in I/R-related microvascular damage in the limb. Methods: Limb viability was evaluated by laser Doppler imaging, tissue edema analysis and histological analysis. Western blotting and immunofluorescence were applied to analyze the levels of apoptosis, oxidative stress, autophagy, transcription factor EB (TFEB) activity and mucolipin 1 (MCOLN1)-calcineurin signaling pathway. Results: SFN administration significantly ameliorated I/R-induced hypoperfusion, tissue edema, skeletal muscle fiber injury and endothelial cell (EC) damage in the limb. Pharmacological inhibition of NFE2L2 (nuclear factor, erythroid 2 like 2) reversed the anti-oxidation and anti-apoptosis effects of SFN on ECs. Additionally, silencing of TFEB by interfering RNA abolished the SFN-induced autophagy restoration, anti-oxidant response and anti-apoptosis effects on ECs. Furthermore, silencing of MCOLN1 by interfering RNA and pharmacological inhibition of calcineurin inhibited the activity of TFEB induced by SFN, demonstrating that SFN regulates the activity of TFEB through the MCOLN1-calcineurin signaling pathway. Conclusion: SFN protects microvascular ECs against I/R injury by TFEB-mediated autophagy restoration and anti-oxidant response.

Dietary Polyphenols Remodel DNA Methylation Patterns of NRF2 in Chronic Disease

The nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor crucial in regulating cellular homeostasis and apoptosis. The NRF2 gene has been implicated in various biological activities, including antioxidant, anti-inflammatory, and anticancer properties. NRF2 can be regulated genetically and epigenetically at the transcriptional, post-transcriptional, and translational levels. Although DNA methylation is one of the critical biological processes vital for gene expression, sometimes, anomalous methylation patterns result in the dysregulation of genes and consequent diseases and disorders. Several studies have reported promoter hypermethylation downregulated NRF2 expression and its downstream targets. In contrast to the unalterable nature of genetic patterns, epigenetic changes can be reversed, opening up new possibilities in developing therapies for various metabolic disorders and diseases. This review discusses the current state of the NRF2-mediated antioxidative and chemopreventive activities of several natural phytochemicals, including sulforaphane, resveratrol, curcumin, luteolin, corosolic acid, apigenin, and most other compounds that have been found to activate NRF2. This epigenetic reversal of hypermethylated NRF2 states provides new opportunities for research into dietary phytochemistry that affects the human epigenome and the possibility for cutting-edge approaches to target NRF2-mediated signaling to prevent chronic disorders.

Hutchinson-Gilford Progeria Syndrome: Cellular Mechanisms and Therapeutic Perspectives

In humans, aging is characterized by a gradual decline of physical and psychological functions, with the concomitant onset of chronic-degenerative diseases, which ultimately lead to death. The study of Hutchinson-Gilford progeria syndrome (HGPS), a premature aging disorder that recapitulates several features of natural aging, has provided important insights into deciphering the aging process. The genetic origin of HGPS is a de novo point mutation in the LMNA gene that drives the synthesis of progerin, mutant version of lamin A. Progerin is aberrantly anchored to the nuclear envelope disrupting a plethora of molecular processes; nonetheless, how progerin exerts a cascade of deleterious alterations at the cellular and systemic levels is not fully understood. Over the past decade, the use of different cellular and animal models for HGPS has allowed the identification of the molecular mechanisms underlying HGPS, paving the way towards the development of therapeutic treatments against the disease. In this review, we present an updated overview of the biology of HGPS, including its clinical features, description of key cellular processes affected by progerin (nuclear morphology and function, nucleolar activity, mitochondrial function, protein nucleocytoplasmic trafficking and telomere homeostasis), as well as discussion of the therapeutic strategies under development.

Phytochemical compound PB125 attenuates skeletal muscle mitochondrial dysfunction and impaired proteostasis in a model of musculoskeletal decline

Impaired mitochondrial function and disrupted proteostasis contribute to musculoskeletal dysfunction. However, few interventions simultaneously target these two drivers to prevent musculoskeletal decline. Nuclear factor erythroid 2-related factor 2 (Nrf2) activates a transcriptional programme promoting cytoprotection, metabolism, and proteostasis. We hypothesized daily treatment with a purported Nrf2 activator, PB125, in Hartley guinea pigs, a model of musculoskeletal decline, would attenuate the progression of skeletal muscle mitochondrial dysfunction and impaired proteostasis and preserve musculoskeletal function. We treated 2- and 5-month-old male and female Hartley guinea pigs for 3 and 10 months, respectively, with the phytochemical compound PB125. Longitudinal assessments of voluntary mobility were measured using Any-MazeTM open-field enclosure monitoring. Cumulative skeletal muscle protein synthesis rates were measured using deuterium oxide over the final 30 days of treatment. Mitochondrial oxygen consumption in soleus muscles was measured using high resolution respirometry. In both sexes, PB125 (1) increased electron transfer system capacity; (2) attenuated the disease/age-related decline in coupled and uncoupled mitochondrial respiration; and (3) attenuated declines in protein synthesis in the myofibrillar, mitochondrial and cytosolic subfractions of the soleus. These effects were not associated with statistically significant prolonged maintenance of voluntary mobility in guinea pigs. Collectively, treatment with PB125 contributed to maintenance of skeletal muscle mitochondrial respiration and proteostasis in a pre-clinical model of musculoskeletal decline. Further investigation is necessary to determine if these documented effects of PB125 are also accompanied by slowed progression of other aspects of musculoskeletal dysfunction. KEY POINTS: Aside from exercise, there are no effective interventions for musculoskeletal decline, which begins in the fifth decade of life and contributes to disability and cardiometabolic diseases. Targeting both mitochondrial dysfunction and impaired protein homeostasis (proteostasis), which contribute to the age and disease process, may mitigate the progressive decline in overall musculoskeletal function (e.g. gait, strength). A potential intervention to target disease drivers is to stimulate nuclear factor erythroid 2-related factor 2 (Nrf2) activation, which leads to the transcription of genes responsible for redox homeostasis, proteome maintenance and mitochondrial energetics. Here, we tested a purported phytochemical Nrf2 activator, PB125, to improve mitochondrial function and proteostasis in male and female Hartley guinea pigs, which are a model for musculoskeletal ageing. PB125 improved mitochondrial respiration and attenuated disease- and age-related declines in skeletal muscle protein synthesis, a component of proteostasis, in both male and female Hartley guinea pigs.

Apparent Opportunities and Hidden Pitfalls: The Conflicting Results of Restoring NRF2-Regulated Redox Metabolism in Friedreich's Ataxia Pre-Clinical Models and Clinical Trials

Friedreich's ataxia (FRDA) is an autosomal, recessive, inherited neurodegenerative disease caused by the loss of activity of the mitochondrial protein frataxin (FXN), which primarily affects dorsal root ganglia, cerebellum, and spinal cord neurons. The genetic defect consists of the trinucleotide GAA expansion in the first intron of FXN gene, which impedes its transcription. The resulting FXN deficiency perturbs iron homeostasis and metabolism, determining mitochondrial dysfunctions and leading to reduced ATP production, increased reactive oxygen species (ROS) formation, and lipid peroxidation. These alterations are exacerbated by the defective functionality of the nuclear factor erythroid 2-related factor 2 (NRF2), a transcription factor acting as a key mediator of the cellular redox signalling and antioxidant response. Because oxidative stress represents a major pathophysiological contributor to FRDA onset and progression, a great effort has been dedicated to the attempt to restore the NRF2 signalling axis. Despite this, the beneficial effects of antioxidant therapies in clinical trials only partly reflect the promising results obtained in preclinical studies conducted in cell cultures and animal models. For these reasons, in this critical review, we overview the outcomes obtained with the administration of various antioxidant compounds and critically analyse the aspects that may have contributed to the conflicting results of preclinical and clinical studies.

Moringa oleifera Lam Leaf Extract Stimulates NRF2 and Attenuates ARV-Induced Toxicity in Human Liver Cells (HepG2)

The World Health Organization (WHO) reported that there are 37 million individuals living with the human immunodeficiency virus (HIV) worldwide, with the majority in South Africa. This chronic disease is managed by the effective use of antiretroviral (ARV) drugs. However, with prolonged use, ARV drug-induced toxicity remains a clinically complex problem. This study investigated the toxicity of ARV drugs on mitochondria and the NRF2 antioxidant pathway and its possible amelioration using Moringa oleifera Lam (MO) leaf extracts. This medicinal plant has a range of functional bioactive compounds. Liver (HepG2) cells were treated with individual ARV drugs: Tenofovir disoproxil fumarate (TDF), Emtricitabine (FTC), and Lamivudine (3TC) for 96 h, followed by MO leaf extracts for 24 h. Intracellular ROS, cytotoxicity, lipid peroxidation, total and reduced glutathione (GSH), ATP, and mitochondrial polarisation were determined. Finally, protein (pNRF2, NRF2, SOD2, CAT, and Sirt3) and mRNA (NRF2, CAT, NQO1 SOD2, Sirt3, and PGC1α) expression were measured using Western blot and qPCR, respectively. TDF, FTC, and 3TC significantly increased intracellular ROS and extracellular levels of both MDA and LDH. ARVs also reduced the GSH and ATP levels and altered the mitochondrial polarization. Further, ARVs reduced the expression of NRF2 SOD2, Sirt3, CAT, NQO1, UCP2 and PGC1α mRNA and consequently pNRF2, NRF2, SOD2, Sirt3 and CAT protein. In contrast, there was a significant reduction in the extracellular MDA and LDH levels post-MO treatment. MO significantly reduced intracellular ROS while significantly increasing GSH, ATP, and mitochondrial membrane polarization. The addition of MO to ARV-treated cells significantly upregulated the expression of NRF2, SOD2, Sirt3, CAT, UCP2, PGC1α, and NQO1 mRNA and pNRF2, NRF2, SOD2, Sirt3 proteins. Thus, MO ameliorates ARV-induced hepatotoxicity by scavenging oxidants by inducing the NRF2 antioxidant pathway. MO shows great therapeutic potential and may be considered a potential supplement to ameliorate ARV drug toxicity.

Mucociliary clearance augmenting drugs block SARS-CoV-2 replication in human airway epithelial cells

The coronavirus disease (COVID-19) pandemic, caused by SARS-CoV-2 coronavirus, is devastatingly impacting human health. A prominent component of COVID-19 is the infection and destruction of the ciliated respiratory cells, which perpetuates dissemination and disrupts protective mucociliary transport (MCT) function, an innate defense of the respiratory tract. Thus, drugs that augment MCT could improve the barrier function of the airway epithelium and reduce viral replication and, ultimately, COVID-19 outcomes. We tested five agents known to increase MCT through distinct mechanisms for activity against SARS-CoV-2 infection using a model of human respiratory epithelial cells terminally differentiated in an air/liquid interphase. Three of the five mucoactive compounds tested showed significant inhibitory activity against SARS-CoV-2 replication. An archetype mucoactive agent, ARINA-1, blocked viral replication and therefore epithelial cell injury; thus, it was further studied using biochemical, genetic, and biophysical methods to ascertain the mechanism of action via the improvement of MCT. ARINA-1 antiviral activity was dependent on enhancing the MCT cellular response, since terminal differentiation, intact ciliary expression, and motion were required for ARINA-1-mediated anti-SARS-CoV2 protection. Ultimately, we showed that the improvement of cilia movement was caused by ARINA-1-mediated regulation of the redox state of the intracellular environment, which benefited MCT. Our study indicates that intact MCT reduces SARS-CoV-2 infection, and its pharmacologic activation may be effective as an anti-COVID-19 treatment.

Redox Modulation of Mitochondrial Proteins in the Neurotoxicant Models of Parkinson's Disease

Significance: Mitochondrial proteins regulate the oxidative phosphorylation, cellular metabolism, and free radical generation. Redox modulation alters the mitochondrial proteins and instigates the damage to dopaminergic neurons. Toxicants contribute to Parkinson's disease (PD) pathogenesis in conjunction with aging and genetic factors. While oxidative modulation of a number of mitochondrial proteins is linked to xenobiotic exposure, little is known about its role in the toxicant-induced PD. Understanding the role of redox modulation of mitochondrial proteins in complex cellular events leading to neurodegeneration is highly relevant. Recent Advances: Many toxicants are shown to inhibit complex I or III and elicit free radical production that alters the redox status of mitochondrial proteins. Implication of redox modulation of the mitochondrial proteins makes them a target to comprehend the underlying mechanism of toxicant-induced PD. Critical Issues: Owing to multifactorial etiology, exploration of onset and progression and treatment outcomes needs a comprehensive approach. The article explains about a few mitochondrial proteins that undergo redox changes along with the promising strategies, which help to alleviate the toxicant-induced redox imbalance leading to neurodegeneration. Future Directions: Although mitochondrial proteins are linked to PD, their role in toxicant-induced parkinsonism is not yet completely known. Preservation of antioxidant defense machinery could alleviate the redox modulation of mitochondrial proteins. Targeted antioxidant delivery, use of metal chelators, and activation of nuclear factor erythroid 2-related factor 2, and combinational therapy that encounters multiple free radicals, could ameliorate the redox modulation of mitochondrial proteins and thereby PD progression.

Graded functional organisation in the left inferior frontal gyrus: evidence from task-free and task-based functional connectivity

The left inferior frontal gyrus (LIFG) has been ascribed key roles in numerous cognitive domains, including language, executive function and social cognition. However, its functional organisation, and how the specific areas implicated in these cognitive domains relate to each other, is unclear. Possibilities include that the LIFG underpins a domain-general function or, alternatively, that it is characterized by functional differentiation, which might occur in either a discrete or a graded pattern. The aim of the present study was to explore the topographical organisation of the LIFG using a bimodal data-driven approach. To this end, we extracted functional connectivity (FC) gradients from 1) the resting-state fMRI time-series of 150 participants (77 female), and 2) patterns of co-activation derived meta-analytically from task data across a diverse set of cognitive domains. We then sought to characterize the FC differences driving these gradients with seed-based resting-state FC and meta-analytic co-activation modelling analyses. Both analytic approaches converged on an FC profile that shifted in a graded fashion along two main organisational axes. An anterior-posterior gradient shifted from being preferentially associated with high-level control networks (anterior LIFG) to being more tightly coupled with perceptually-driven networks (posterior). A second dorsal-ventral axis was characterized by higher connectivity with domain-general control networks on one hand (dorsal LIFG), and with the semantic network, on the other (ventral). These results provide novel insights into a graded functional organisation of the LIFG underpinning both task-free and task-constrained mental states, and suggest that the LIFG is an interface between distinct large-scale functional networks.

Mucociliary Clearance Augmenting Drugs Block SARS-Cov-2 Replication in Human Airway Epithelial Cells

The coronavirus disease (COVID-19) pandemic, caused by SARS-CoV-2 coronavirus, is devastatingly impacting human health. A prominent component of COVID-19 is the infection and destruction of the ciliated respiratory cells, which perpetuates dissemination and disrupts protective mucociliary transport (MCT) function, an innate defense of the respiratory tract. Thus, drugs that augment MCT could improve barrier function of the airway epithelium, reduce viral replication and, ultimately, COVID-19 outcomes. We tested five agents known to increase MCT through distinct mechanisms for activity against SARS-CoV-2 infection using a model of human respiratory epithelial cells terminally differentiated in an air/liquid interphase. Three of the five mucoactive compounds tested showed significant inhibitory activity against SARS-CoV-2 replication. An archetype mucoactive agent, ARINA-1, blocked viral replication and therefore epithelial cell injury, thus, it was further studied using biochemical, genetic and biophysical methods to ascertain mechanism of action via improvement of MCT. ARINA-1 antiviral activity was dependent on enhancing the MCT cellular response, since terminal differentiation, intact ciliary expression and motion was required for ARINA-1-mediated anti-SARS-CoV2 protection. Ultimately, we showed that improvement of cilia movement was caused by ARINA-1-mediated regulation of the redox state of the intracellular environment, which benefited MCT. Our study indicates that Intact MCT reduces SARS-CoV-2 infection, and its pharmacologic activation may be effective as an anti-COVID-19 treatment.

Rescue of Mitochondrial Function in Hutchinson-Gilford Progeria Syndrome by the Pharmacological Modulation of Exportin CRM1

Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disorder caused by the expression of progerin, a mutant variant of Lamin A. Recently, HGPS studies have gained relevance because unraveling its underlying mechanism would help to understand physiological aging. We previously reported that the CRM1-mediated nuclear protein export pathway is exacerbated in HGPS cells, provoking the mislocalization of numerous protein targets of CRM1. We showed that normalization of this mechanism by pharmacologically inhibiting CRM1 with LMB (specific CRM1 inhibitor), mitigates the senescent phenotype of HGPS cells. Since mitochondrial dysfunction is a hallmark of HGPS, in this study we analyze the effect of LMB on mitochondrial function. Remarkably, LMB treatment induced the recovery of mitochondrial function in HGPS cells, as shown by the improvement in mitochondrial morphology, mitochondrial membrane potential, and ATP levels, which consequently impeded the accumulation of ROS but not mitochondrial superoxide. We provide evidence that the beneficial effect of LMB is mechanistically based on a combinatory effect on mitochondrial biogenesis via upregulation of PGC-1α expression (master transcription cofactor of mitochondrial genes), and mitophagy through the recovery of lysosomal content. The use of exportin CRM1 inhibitors constitutes a promising strategy to treat HGPS and other diseases characterized by mitochondrial impairment.

Hydralazine Revives Cellular and Ocular Lens Health-Span by Ameliorating the Aging and Oxidative-Dependent Loss of the Nrf2-Activated Cellular Stress Response

A major hallmark of aging-associated diseases is the inability to evoke cellular defense responses. Transcriptional protein Nrf2 (nuclear factor erythroid-derived 2-related factor) plays a pivotal role in the oxidative stress response, cellular homeostasis, and health span. Nrf2's activation has been identified as a therapeutic target to restore antioxidant defense in aging. Here, we demonstrated that FDA-approved drug, hydralazine (Hyd), was a reactivator of the Nrf2/ARE (antioxidant response element) pathway in various ages and types of mouse (m) or human (h) lens epithelial cells (LECs) and mice lenses in-vitro/in-vivo. This led to Hyd-driven abatement of carbonyls, reduced reactive oxygen species (ROS), and reduced 4-HNE/MDA-adducts with cytoprotection, and extended lens healthspan by delaying/preventing lens opacity against aging/oxidative stress. We elucidated that Hyd activated the protective signaling by inducing Nrf2 to traverse from the cytoplasm to the nucleus and potentiated the ARE response by direct interaction of Nrf2 and ARE sequences of the promoter. Loss-of-function study and cotreatment of Hyd and antioxidant, N-acetyl cysteine (NAC) or Peroxiredoxin (Prdx)6, specified that Nrf2/ARE-driven increase in the promoter activity was Hyd-dependent. Our study provides proof-of concept evidence and, thereby, paves the way to repurposing Hyd as a therapeutic agent to delay/prevent aging and oxidative-related disorders.

Sulforaphane, an Nrf-2 Agonist, Modulates Oxidative Stress and Inflammation in a Rat Model of Cuprizone-Induced Cardiotoxicity and Hepatotoxicity

Cuprizone (CPZ) is a neurotoxic agent that is used to induce demyelination and neurotoxicity in rats. This study aimed to investigate the protective potential of sulforaphane (SF), nuclear factor E2 related factor (Nrf-2) activator, against CPZ-induced cardiotoxicity and hepatotoxicity. Male adult Wistar rats (n = 18) were fed with a regular diet or a CPZ-contained diet (0.2%) for four weeks. The rats were divided into three groups (n = 6): negative control rats, CPZ-exposed rats, and CPZ + SF treated rats. SF was intraperitoneally administrated (2 mg/kg/day) for two weeks. The anti-inflammatory and anti-oxidative functions of SF were investigated biochemically, histologically, and immunohistochemically. CPZ increased serum levels of cardiac troponin 1 (CTn1), aspartate amino transaminase (AST), alanine amino transaminase (ALT), and alkaline phosphatase (ALP). In addition, serum levels of inflammatory interferon-gamma (IFN-γ), and pro-inflammatory interleukin 1β (IL-1β) were significantly elevated. Moreover, CPZ administration provoked oxidative stress as manifested by declined serum levels of total antioxidant capacity (TAC), as well as, stimulated lipid peroxidation and decreased catalase activities in both cardiac and hepatic tissues. SF treatment reversed all these biochemical alterations through exerting anti-oxidative and anti-inflammatory activities, and this was supported by histopathological investigations in both cardiac and hepatic tissues. This SF-triggered modulation of oxidative stress and inflammation is strongly associated with Nrf-2 activation, as evidenced by activated immunoexpression in both cardiac and hepatic tissues. This highlights the cardioprotective and hepatoprotective activities of SF via Nrf-2 activation and enhancing catalase function.

Sulforaphane alleviated vascular remodeling in hypoxic pulmonary hypertension via inhibiting inflammation and oxidative stress

Hypoxic pulmonary hypertension (HPH) is a cardiopulmonary disease featured by pulmonary vascular remodeling, which is due to abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs) and dysfunction of endothelial cells (ECs). Sulforaphane (SFN) is a natural isothiocyanate extracted from cruciferous vegetables with promising anti-inflammatory and anti-oxidative activities. This study aimed to explore the effect and mechanism of SFN on HPH. Male mice were exposed to persistent chronic hypoxia for 4 weeks to induce HPH. The results demonstrated that SFN repressed the increased right ventricular systolic pressure (RVSP) and attenuated the right ventricular hypertrophy and pulmonary arteries remodeling in HPH mice. In particular, after SFN treatment, the CD68 positive cells in lung sections were reduced; TNF-α and IL-6 levels in lungs and serum declined; activation of NF-κB in PASMCs was inhibited in response to hypoxia. Besides, SFN enhanced the superoxide dismutase (SOD) activity in serum, SOD2 expression, total glutathione levels, and GSH/GSSG ratio in PASMCs, along with a decrease in malondialdehyde (MDA) contents in serum and ROS production in PASMCs after hypoxia exposure. Notably, SFN, as an Nrf2 activator, reversed the reduction in Nrf2 expression in hypoxic PASMCs. In vitro, SFN treatment inhibited hyperproliferation and promoted apoptosis of PASMCs under hypoxia conditions. SFN also prevented the apoptosis of pulmonary microvascular ECs caused by hypoxia. Therefore, these data suggested that SFN could significantly restrain the inflammation and oxidative stress, thereby inhibiting PASMCs proliferation, promoting PASMCs apoptosis, and reversing hypoxia injury in ECs to improve pulmonary vascular remodeling.

Sustained release of sulforaphane by bioactive extracellular vesicles for neuroprotective effect on chick model

Novel studies have shown neurological treatment possibilities with extracellular vesicles (EVs) as natural particles with a special composition that are produced by different cell types. Their stability, natural structure, composition, and bioavailability make them good candidates as drug vehicles. Here, EVs were isolated from amniotic fluid (AF) through differential centrifugation, and characterized for size (<200 nm), structure, and composition, their effectiveness on the human PC12 cell line, and brain of chick embryos exposed to sodium valproate (animal autistic model). Sulforaphane (SFN) was employed as a bioactive compound and then encapsulated into Evs using three methods including passive (incubation), active (sonication), and active-passive (sonication-incubation). Further, the loading and in vitro releases of SFN fitted the Korsmeyer-Peppas (R²  = 0.99) kinetic model by non-Fickian diffusion case II (n = 0.44, passive loading) and Fickian diffusion case I (n = 0.41, active and active-passive loading). SFN-loaded EVs (SFN@EVs; 11 μM: 103 nM) stimulated hPC-12 cell proliferation. The gene expression analysis revealed that SFN@EVs could upregulate Nrf2 and reduce IL-6 expression. Eventually, histopathological results of the coronal cross-section of the chick embryos brain showed treatment with SFN@EVs. This treatment illustrated normality in the gray and white matter and the orientation of the bipolar neurons. Our findings showed EVs' potentially acting as a gene expression regulator in autism spectrum disorder.

Dynamic alterations of immunosenescence-related genes in older women with breast cancer receiving chemotherapy: A prospective study

BACKGROUND

The exact impact of chemotherapy on the immune system of older patients with breast cancer is not well known. A longitudinal study was performed investigating the evolution of the blood immune profile during and after chemotherapy in this population.

PATIENTS AND METHODS

The study included 39 patients receiving adjuvant chemotherapy (chemotherapy group, CTG) and 32 patients receiving only hormone therapy (control group, CG). A 10-gene panel associated with immunosenescence was measured in peripheral blood mononuclear cells (PBMC) before (T1), at 3 months (T2) and at 12 months (T3) after initiation of adjuvant therapy. Nutrition status was assessed by using a mini nutritional assessment scale. Linear mixed model analyses were performed for trajectory evolution, with or without adjusting for age, tumor stage, breast cancer phenotype, and/or corresponding baseline gene levels.

RESULTS

Six genes relating to T cell activation (CD28, CD27, CD86, LCK, GRAP, LRRN3), and two genes relating to oxidative stress (PRDX6, HMOX1) exhibited a significant group-by-time effect, even after adjusting covariates(p≤ 0.01). In CTG, the T cell activation genes substantially declined from T1 to T2 and bounced back to a level higher than baseline at T3 (p<0.03), which was not observed in CG (p>0.26). Patients with malnutrition detected at T1 experienced more pronounced perturbation regarding CD27, LCK, CD69, VAMP5, and LRRN3 (p<0.05).

CONCLUSION

Chemotherapy leads to transient perturbation of immune-related gene expression and potentially stimulates immunity in the long term. Well-nourished patients experience less impact of chemotherapy on immune-related gene expression profiles.

Obligatory Role of AMPK Activation and Antioxidant Defense Pathway in the Regulatory Effects of Metformin on Cellular Protection and Prevention of Lens Opacity

Increasing levels of oxidative-stress due to deterioration of the Nrf2 (NFE2-related factor)/ARE (antioxidant response element) pathway is found to be a primary cause of aging pathobiology. Metformin having anti-aging effects can delay/halt aging-related diseases. Herein, using lens epithelial cell lines (LECs) of human (h) or mouse (m) and aging h/m primary LECs along with lenses as model systems, we demonstrated that Metformin could correct deteriorated Bmal1/Nrf2/ARE pathway by reviving AMPK-activation, and transcriptional activities of Bmal1/Nrf2, resulting in increased antioxidants enzymatic activity and expression of Phase II enzymes. This ensued reactive oxygen species (ROS) mitigation with cytoprotection and prevention of lens opacity in response to aging/oxidative stress. It was intriguing to observe that Metformin internalized lens/LECs and upregulated OCTs (Organic Cation Transporters). Mechanistically, we found that Metformin evoked AMPK activation-dependent increase of Bmal1, Nrf2, and antioxidants transcription by promoting direct E-Box and ARE binding of Bmal1 and Nrf2 to the promoters. Loss-of-function and disruption of E-Box/ARE identified that Metformin acted by increasing Bmal1/Nrf2-mediated antioxidant expression. Data showed that AMPK-activation was a requisite for Bmal1/Nrf2-antioxidants-mediated defense, as pharmacologically inactivating AMPK impeded the Metformin's effect. Collectively, the results for the first-time shed light on the hitherto incompletely uncovered crosstalk between the AMPK and Bmal1/Nrf2/antioxidants mediated by Metformin for blunting oxidative/aging-linked pathobiology.

Sp1-Mediated Prdx6 Upregulation Leads to Clasmatodendrosis by Increasing Its aiPLA2 Activity in the CA1 Astrocytes in Chronic Epilepsy Rats

Clasmatodendrosis is an autophagic astroglial degeneration (a non-apoptotic (type II) programmed cell death) whose underlying mechanisms are fully understood. Peroxiredoxin-6 (Prdx6), the “non-selenium glutathione peroxidase (NSGPx)”, is the only member of the 1-cysteine peroxiredoxin family. Unlike the other Prdx family, Prdx6 has multiple functions as glutathione peroxidase (GPx) and acidic calcium-independent phospholipase (aiPLA2). The present study shows that Prdx6 was upregulated in CA1 astrocytes in chronic epilepsy rats. 2-Cyano-3,12-dioxo-oleana-1,9(11)-dien-28-oic acid methyl ester (CDDO-Me) and N-acetylcysteine (NAC, a precursor of glutathione) ameliorated clasmatodendrosis accompanied by reduced Prdx6 level in CA1 astrocytes. Specificity protein 1 (Sp1) expression was upregulated in CA1 astrocyte, which was inhibited by mithramycin A (MMA). MMA alleviated clasmatodendrosis and Prdx6 upregulation. Sp1 expression was also downregulated by CDDO-Me and NAC. Furthermore, 1-hexadecyl-3-(trifluoroethgl)-sn-glycerol-2 phosphomethanol (MJ33, a selective inhibitor of aiPLA2 activity of Prdx6) attenuated clasmatodendrosis without affecting Prdx6 expression. All chemicals shortened spontaneous seizure duration but not seizure frequency and behavioral seizure severity in chronic epilepsy rats. Therefore, our findings suggest that Sp1 activation may upregulate Prdx6, whose aiPLA2 activity would dominate over GPx activity in CA1 astrocytes and may lead to prolonged seizure activity due to autophagic astroglial degeneration.

Redox-based disruption of cellular hormesis and promotion of degenerative pathways: perspectives on ageing processes

The present work aims to link the redox and cell-centric theories of chronic processes in human biology, focusing on ageing. A synthetic overview of cellular redox pathways will be integrated by the concept of hormesis, which disruption leads to several physiopathological processes. The onset of age-related diseases due to the restriction of homeodynamic capacity will be herein considered in a redox fashion. Up-to-date arguments on hormetic agents, such as geroprotectors, dietary interventions, and physical exercise are refining the presented theoretical framework, integrated by insights from extracellular vesicles, microbiota, pollutants, and timing mechanisms. The broad concepts of exposome encompass the redox-based alteration of cellular hormesis for providing meaningful perspectives on redox biogerontology.

Immunomodulatory Effects of (R)-Sulforaphane on LPS-Activated Murine Immune Cells: Molecular Signaling Pathways and Epigenetic Changes in Histone Markers

The aim of this study was to explore the immunomodulatory effects of the natural enantiomer (R)-Sulforaphane (SFN) and the possible signaling pathways involved in an ex vivo model of LPS-stimulated murine peritoneal macrophages. Furthermore, we studied the epigenetic changes induced by (R)-SFN as well as the post-translational modifications of histone H3 (H3K9me3 and H3K18ac) in relation to the production of cytokines in murine splenocytes after LPS stimulation. (R)-SFN was able to modulate the inflammatory response and oxidative stress induced by LPS stimulation in murine peritoneal macrophages through the inhibition of reactive oxygen species (ROS), nitric oxide (NO) and cytokine (IL-1β, IL-6, IL-17, IL-18 and TNF-α) production by down-regulating the expression of pro-inflammatory enzymes (iNOS, COX-2 and mPGES-1). We also found that activation of the Nrf-2/HO-1 axis and inhibition of the JAK2/STAT-3, MAPK, canonical and non-canonical inflammasome signaling pathways could have been responsible for the immunomodulatory effects of (R)-SFN. Furthermore, (R)-SFN modulated epigenetic modifications through histone methylation (H3K9me3) and deacetylation (H3K18ac) in LPS-activated spleen cells. Collectively, our results suggest that (R)-SFN could be a promising epinutraceutical compound for the management of immunoinflammatory diseases.

The effect of sulforaphane on perinatal hypoxic-ischemic brain injury in rats

Perinatal hypoxic-ischemic insult (HII) is one of the main devastating causes of morbidity and mortality in newborns. HII induces brain injury which evolves to neurological sequelae later in life. Hypothermia is the only therapeutic approach available capable of diminishing brain impairment after HII. Finding a novel therapeutic method to reduce the severity of brain injury and its consequences is critical in neonatology. The present paper aimed to evaluate the effect of sulforaphane (SFN) pre-treatment on glucose metabolism, neurodegeneration, and functional outcome at the acute, sub-acute, and sub-chronic time intervals in the experimental model of perinatal hypoxic-ischemic insult in rats. To estimate the effect of SFN on brain glucose uptake we have performed 18F-deoxyglucose (FDG) microCT/PET. The activity of FDG was determined in the hippocampus and sensorimotor cortex. Neurodegeneration was assessed by histological analysis of Nissl-stained brain sections. To investigate functional outcomes a battery of behavioral tests was employed. We have shown that although SFN possesses a protective effect on glucose uptake in the ischemic hippocampus 24 h and 1 week after HII, no effect has been observed in the motor cortex. We have further shown that the ischemic hippocampal formation tends to be thinner in HIE and SFN treatment tends to reverse this pattern. We have observed subtle chronic movement deficit after HII detected by ladder rung walking test with no protective effect of SFN. SFN should be thus considered as a potent neuroprotective drug with the capability to interfere with pathophysiological processes triggered by perinatal hypoxic-ischemic insult.

Role and Mechanism of Keap1/Nrf2 Signaling Pathway in the Regulation of Autophagy in Alleviating Pulmonary Fibrosis

A variety of internal and external lung diseases may eventually lead to pulmonary fibrosis, and insufficient autophagy is closely related to pulmonary fibrosis. This research is aimed to explore the mechanism of autophagy to alleviate pulmonary fibrosis. Then, a mouse model of pulmonary fibrosis induced by boromycin and histopathological lesions of the lungs of mice were observed by HE staining, which Masson staining assessed the degree of fibrosis in the lung tissue by detecting the expression of hydroxyproline in the tissue. RT-qPCR and western blotting were used to detect the levels of autophagy and Keap1/Nrf2 signaling pathway-related proteins. It was proved that autophagy-related proteins MAP1LC3(LC3) and Beclin 1 were decreased in mice with pulmonary fibrosis, while the expression of p62 was increased. Mice with pulmonary fibrosis worsened after injection of a 3-MA autophagy inhibitor, while injection of autophagy activation of rapamycin agent promoted Nrf2 nuclear mobilization. In a word, autophagy relieves pulmonary fibrosis through the activation of the Keap1/Nrf2 signaling pathway.

Investigating the effect of Sulforaphane on AMPK/AKT/NRF2 pathway in human granulosa-lutein cells under H2O2-induced oxidative stress

Excessive production of reactive oxygen species (ROS) in granulosa cells (GCs) plays a role in pathogenesis of polycystic ovarian syndrome (PCOS) by developing oxidative stress (OS). It was shown that Sulforaphane (SFN), with known antioxidant properties, can have protective effects in different diseases through affecting the nuclear factor (erythroid-derived 2)-like 2 (NRF2) signaling pathway. Thus, the purpose of the current work was to examine the protective impact of SFN through the activation of the AMPK/AKT/NRF2 pathway against OS produced by H2O2 in granulosa-lutein cells (GLCs). Individuals' GLCs were obtained during ovum retrieval in intracytoplasmic sperm injection (ICSI) cycles. First, the induced OS model was created in GLCs using H₂O₂ exposure. To examine the protective effect of SFN against OS, the cells were cultured for 24 h in presence or absence of SFN. Eventually, the levels of intracellular ROS and apoptosis were measured by flow cytometry, and genes and proteins expression levels of AMPK, AKT, and NRF2 were evaluated using qRT-PCR and western blotting. Compared to the control group, the levels of intracellular ROS and apoptosis rose dramatically in GLCs with enhanced OS. SFN therapy decreased ROS and apoptosis levels and increased the overexpression of AMPK, AKT, and NRF2 genes and proteins. This study's results revealed that SFN exposure results in the alleviation of ROS and apoptosis levels possibly through activating the overexpression of genes and proteins of AMPK, AKT, and NRF2, and exerts its protective effects against OS in GLCs.

Sulforaphane Acts Through NFE2L2 to Prevent Hypoxia-Induced Apoptosis in Porcine Granulosa Cells via Activating Antioxidant Defenses and Mitophagy

In mammals, a vast majority of ovarian follicles undergo atresia, which is caused by granulosa cell (GC) apoptosis. GCs in follicles are exposed to low oxygen. Hypoxia triggers reactive oxygen species (ROS) generation, which leads to cell oxidative stress and apoptosis. Sulforaphane (SFN), a phytochemical isothiocyanate enriched in cruciferous vegetables, has exhibited a crucial role in mitigating oxidative stress. To explore the effect of SFN on porcine GC apoptosis in a hypoxic environment, we handled the established hypoxia model (1% O₂) of cultured porcine GCs with SFN. Results showed that SFN rescued hypoxia-induced apoptosis and viability of GCs. Meanwhile, SFN increased the expression of antioxidant enzymes and reduced the accumulation of ROS in GC cytoplasm and mitochondria under hypoxia. Mechanically, SFN activated the transcription factor of redox-sensitive nuclear factor-erythroid 2-related factor 2 (NFE2L2) entering the nucleus, further inducing mitophagy and increased antioxidant capacity, finally alleviating the adverse effect of hypoxia on porcine GCs. In conclusion, SFN inhibited hypoxia-evoked GC apoptosis by activating antioxidant defenses and mitophagy through NFE2L2. New targets may be provided for regulating follicular development and atresia by these findings.

Long-lasting beneficial effects of maternal intake of sulforaphane glucosinolate on gut microbiota in adult offspring

Mounting evidence suggests the impact of maternal diet on the health of offspring. We reported that maternal diet of sulforaphane glucosinolate (SGS) could prevent behavioral abnormalities in offspring after maternal immune activation. The present study was designed to investigate whether the dietary intake of SGS during pregnancy and lactation influences the composition of gut microbiota in the offspring. The dietary intake of SGS during pregnancy and lactation caused significant changes in the α-diversity and β-diversity of gut microbiota in 3-week-old offspring (SGS-3W group) and 10-week-old offspring (SGS-10W group). The LEfSe algorithm identified several microbes as important phylotypes in the SGS-3W or SGS-10W groups. Predictive functional metagenomes showed that the maternal intake of SGS caused several KEGG pathways alterations with respect to the genetic information processing and metabolism. Furthermore, the plasma levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the SGS-10W group after the injection of lipopolysaccharide (LPS: 0.5 mg/kg) were significantly lower than those of the CON-10W group. It is noteworthy that there were positive correlations between the relative abundance of the genus Blautia and IL-6 (or TNF-α) in adult offspring. Moreover, there were sex differences of gut microbiota composition in offspring. In conclusion, these data suggest that the dietary intake of SGS during pregnancy and lactation might produce long-lasting beneficial effects in adult offspring through the persistent modulation of gut microbiota. It is likely that the modulation of gut microbiota by maternal nutrition may confer resilience versus vulnerability to stress-related psychiatric disorders in the offspring.

Nicotinamide Mononucleotide Administration Restores Redox Homeostasis via the Sirt3-Nrf2 Axis and Protects Aged Mice from Oxidative Stress-Induced Liver Injury

Altered adaptive homeostasis contributes to aging and lifespan regulation. In the present study, to characterize the mechanism of aging in mouse liver, we performed quantitative proteomics and found that the most upregulated proteins were related to the oxidation-reduction process. Further analysis revealed that malondialdehyde (MDA) and protein carbonyl (PCO) levels were increased, while nuclear Nrf2 and downstream genes were significantly increased, indicating that oxidative stress induced Nrf2 activation in aged mouse liver. Importantly, nicotinamide mononucleotide (NMN) administration decreased the oxidative stress and the nuclear Nrf2 and Nrf2 downstream gene levels. Indeed, aged mice treated with NMN improved stress resistance against acetaminophen (APAP)-induced liver injury, indicating that NMN restored Nrf2-mediated adaptive homeostasis. Further studies found that NMN increased Sirt3 activities to deacetylate age-associated acetylation at K68 and K122 in Sod2, while its effects on nuclear Nrf2 levels were diminished in Sirt3-deficient mice, suggesting that NMN-enhanced adaptive homeostasis was Sirt3-dependent. Taken together, we demonstrated that Nrf2-regulated adaptive homeostasis was decreased in aged mouse liver and NMN supplementation restored liver redox homeostasis via the Sirt3-Nrf2 axis and protected aged liver from oxidative stress-induced injury.

The Role of Organosulfur Compounds as Nrf2 Activators and Their Antioxidant Effects

Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling has become a key pathway for cellular regulation against oxidative stress and inflammation, and therefore an attractive therapeutic target. Several organosulfur compounds are reportedly activators of the Nrf2 pathway. Organosulfur compounds constitute an important class of therapeutic agents in medicinal chemistry due to their ability to participate in biosynthesis, metabolism, cellular functions, and protection of cells from oxidative damage. Sulfur has distinctive chemical properties such as a large number of oxidation states and versatility of reactions that promote fundamental biological reactions and redox biochemistry. The presence of sulfur is responsible for the peculiar features of organosulfur compounds which have been utilized against oxidative stress-mediated diseases. Nrf2 activation being a key therapeutic strategy for oxidative stress is closely tied to sulfur-based chemistry since the ability of compounds to react with sulfhydryl (-SH) groups is a common property of Nrf2 inducers. Although some individual organosulfur compounds have been reported as Nrf2 activators, there are no papers with a collective analysis of these Nrf2-activating organosulfur compounds which may help to broaden the knowledge of their therapeutic potentials and motivate further research. In line with this fact, for the first time, this review article provides collective and comprehensive information on Nrf2-activating organosulfur compounds and their therapeutic effects against oxidative stress, thereby enriching the chemical and pharmacological diversity of Nrf2 activators.

Melatonin and multiple sclerosis: antioxidant, anti-inflammatory and immunomodulator mechanism of action

BACKGROUND

Melatonin is an indole hormone secreted primarily by the pineal gland that showing anti-oxidant, anti-inflammatory and anti-apoptotic capacity. It can play an important role in the pathophysiological mechanisms of various diseases. In this regard, different studies have shown that there is a relationship between Melatonin and Multiple Sclerosis (MS). MS is a chronic immune-mediated disease of the Central Nervous System.

AIM

The objective of this review was to evaluate the mechanisms of action of melatonin on oxidative stress, inflammation and intestinal dysbiosis caused by MS, as well as its interaction with different hormones and factors that can influence the pathophysiology of the disease.

RESULTS

Melatonin causes a significant increase in the levels of catalase, superoxide dismutase, glutathione peroxidase, glutathione and can counteract and inhibit the effects of the NLRP3 inflammasome, which would also be beneficial during SARS-CoV-2 infection. In addition, melatonin increases antimicrobial peptides, especially Reg3β, which could be useful in controlling the microbiota.

CONCLUSION

Melatonin could exert a beneficial effect in people suffering from MS, running as a promising candidate for the treatment of this disease. However, more research in human is needed to help understand the possible interaction between melatonin and certain sex hormones, such as estrogens, to know the potential therapeutic efficacy in both men and women.

Biological mechanisms and clinical efficacy of sulforaphane for mental disorders

Current clinical management of major mental disorders, such as autism spectrum disorder, depression and schizophrenia, is less than optimal. Recent scientific advances have indicated that deficits in oxidative and inflammation systems are extensively involved in the pathogenesis of these disorders. These findings have led to expanded considerations for treatment. Sulforaphane (SFN) is a dietary phytochemical extracted from cruciferous vegetables. It is an effective activator of the transcription factor nuclear erythroid-2 like factor-2, which can upregulate multiple antioxidants and protect neurons against various oxidative damages. On the other hand, it can also significantly reduce inflammatory response to pathological states and decrease the damage caused by the immune response via the nuclear factor-κB pathway and other pathways. In this review, we introduce the biological mechanisms of SFN and the pilot evidence from its clinical trials of major mental disorders, hoping to promote an increase in psychiatric clinical studies of SFN.

Role of sulforaphane in endoplasmic reticulum homeostasis through regulation of the antioxidant response

Nowadays, the nutraceutical agent sulforaphane (SFN) shows great versatility in turning on different cellular responses. Mainly, this isothiocyanate acts as a master regulator of cellular homeostasis due to its antioxidant response and cytoplasmic, mitochondrial, and endoplasmic reticulum (ER) protein modulation. Even more, SFN acts as an effective strategy to counteract oxidative stress, apoptosis, and ER stress, among others as seen in different injury models. Particularly, ER stress is buffered by the unfolded protein response (UPR) activation, which is the first instance in orchestrating the recovery of ER function. Interestingly, different studies highlight a close interrelationship between ER stress and oxidative stress, two events driven by the accumulation of reactive oxygen species (ROS). This response inevitably perpetuates itself and acts as a vicious cycle that triggers the development of different pathologies, such as cardiovascular diseases, neurodegenerative diseases, and others. Accordingly, it is vital to target ER stress and oxidative stress to increase the effectiveness of clinical therapies used to treat these diseases. Therefore, our study is focused on the role of SFN in preserving cellular homeostasis balance by regulating the ER stress response through the Nrf2-modulated antioxidant pathway.

Switching of Redox Signaling by Prdx6 Expression Decides Cellular Fate by Hormetic Phenomena Involving Nrf2 and Reactive Oxygen Species

Changes in intracellular reactive oxygen species (ROS) levels due to remodeling of antioxidant defense can affect the status of biological homeostasis in aging/oxidative stress. Peroxiredoxin 6 (Prdx6), an antioxidant gene downstream target for the Nrf2 pathway, plays a role in regulating ROS homeostasis. Using aging human (h) lens epithelial cells (LECs) or Prdx6-deficient (Prdx6^-/-) mouse (m) LECs, here we showed that dichlorofluorescein (DCF) oxidation or H₂O₂ were strictly controlled by Prdx6. We observed that a moderate degree of oxidative stress augmented Nrf2-mediated Prdx6 expression, while higher doses of H₂O₂ (≥100 µM) caused a dramatic loss of Prdx6 expression, resulting in increased DCF oxidation and H₂O₂ amplification and cell death. Mechanistically, at increased oxidative stress, Nrf2 upregulated transcriptional factor Klf9, and that Klf9 bound to the promoter and repressed the Prdx6 gene. Similarly, cells overexpressing Klf9 displayed Klf9-dependent Prdx6 suppression and DCF oxidation with H₂O₂ amplification, while ShKlf9 reversed the process. Our data revealed that H₂O₂ and DCF oxidation levels play a hormetical role, and the Nrf2-Klf9-Prdx6 pathway is pivotal for the phenomena under the conditions of oxidative load/aging. On the whole, the results demonstrate that oxidative hormetical response is essentially based on levels of oxidative triggering and the status of Klf9-Prdx6 pathway activation; thus, Klf9 can be considered as a therapeutic target for hormetic shifting of cellular defense to improve protective resilience to oxidative stress.

CRISPR-Cas9-based genome-wide screening identified novel targets for treating sorafenib-resistant hepatocellular carcinoma: a cross-talk between FGF21 and the NRF2 pathway

The treatment of hepatocellular carcinoma (HCC) has been dominated by multikinase inhibitors for more than a decade. However, drug resistance can severely restrict the efficacy of these drugs. Using CRISPR/CAS9 genome library screening, we evaluated Kelch-like ECH-associated protein 1 (KEAP1) as a key regulator of sorafenib's susceptibility in HCC. We also investigated whether KEAP1's knockdown can stabilize nuclear factor (erythroid-derived 2)-like 2 (NRF2) protein levels that led to sorafenib's resistance, including an NRF2 inhibitor that can synergize with sorafenib to abolish HCC's growth in vitro and in vivo. Furthermore, we clarified that fibroblast growth factor 21 (FGF21) is an important downstream regulator of NRF2 in HCC. Intriguingly, we observed that FGF21 bound to NRF2 through the C-terminus of FGF21, thereby stabilizing NRF2 by reducing its ubiquitination and generating a positive feedback loop in sorafenib-resistant HCC. These findings, therefore, propose that targeting FGF21 is a promising strategy to combat HCC sorafenib's resistance.