Nrf2-ARE Pathway Research Articles

CircRNA_SLC8A1 alleviates hypertrophic scar progression by mediating the Nrf2-ARE pathway.

Hypertrophic scar (HS) is associated with cosmetic defects, mobility, and functional impairments, pruritus, and pain. Previous circRNA microarray analysis identified reduced expression of circRNA_SLC8A1 in HS tissues. Therefore, this study aims to investigate the role of circRNA_SLC8A1 in modulating the abnormal behavior of HS-derived fibroblasts (HSFs) in vitro. RT-qPCR and FISH assays were used to assess the differential expression and localization of circRNA_SLC8A1 in normal and HS tissues. Following modulation of circRNA_SLC8A1 expression, CCK-8, flow cytometry, Transwell, and wound healing assays were employed to evaluate the effects of circRNA_SLC8A1 on the biological behaviors of HSFs. The Starbase database, dual-luciferase reporter assays, and Ago2-RIP assays were utilized to predict and validate the interaction between circRNA_SLC8A1 and downstream miRNAs. CircRNA_SLC8A1 was found to be downregulated in HS tissues and was primarily localized in the cytoplasm. Overexpression of circRNA_SLC8A1 reduced cell viability, cell invasion, wound healing, and the expression of Vimentin, N-cadherin, Col I, and Col III, while enhancing apoptosis and E-cadherin expression in HSFs. CircRNA_SLC8A1 activates the Nrf2-ARE pathway by competitively binding to miRNA-27a-3p. miRNA-27a-3p and Nrf2 exhibited high and low expression, respectively in HS tissues, with an inverse correlation between their levels. Overexpression of miRNA-27a-3p counteracted the effects of circRNA_SLC8A1 in HSF proliferation, apoptosis, migration, EMT, collagen deposition, and Nrf2-ARE pathway activity. CircRNA_SLC8A1 inhibits the proliferation, migration, EMT, and collagen deposition of HSF through competitive binding with miRNA-27a-3p, thereby activating the Nrf2-ARE pathway. The circRNA_SLC8A1/miRNA-27a-3p/Nrf2-ARE axis may offer a promising molecular target for HS therapy.

Microbially mediated phenolic catabolites exert differential genoprotective activities in normal and adenocarcinoma cell lines

Age-associated decline of nuclear factor erythroid 2-related factor 2 (Nrf2) activity and DNA repair efficiency leads to the accumulation of DNA damage and increased risk of cancer. Understanding the mechanisms behind increased levels of damaged DNA is crucial for developing interventions to mitigate age-related cancer risk. Associated with various health benefits, (poly)phenols and their microbially mediated phenolic catabolites represent a potential means to reduce DNA damage. Four colonic-microbiota-derived phenolic catabolites were investigated for their ability to reduce H2O2-induced oxidative DNA damage and modulate the Nrf2-Antixoidant Response Element (ARE) pathway, in normal (CCD 841 CoN) and adenocarcinoma (HT29) colonocyte cell lines. Each catabolite demonstrated significant (p < .001) genoprotective activity and modulation of key genes in the Nrf2-ARE pathway. Overall, the colon-derived phenolic metabolites, when assessed at physiologically relevant concentrations, reduced DNA damage in both normal and adenocarcinoma colonic cells in response to oxidative challenge, mediated in part via upregulation of the Nrf2-ARE pathway.

Studies on the antioxidant mechanisms of betacyanins from improved fermented red dragon fruit (Hylocereus polyrhizus) drink in HepG2 cells

Red dragon fruit (RDF, Hylocereus polyrhizus) is high in betacyanins content but is understudied for its antioxidant mechanisms in liver cells. The present study aimed to investigate the antioxidant mechanisms of the stabilised betacyanins in a novel RDF functional drink, Improved-FRDFD-dH2O (produced from mild, sustainable approaches) using HepG2 cell line. Results revealed the betacyanins of Improved-FRDFD-dH2O (12.5% and 25%, v/v) showed the highest direct scavenging effect on intracellular ROS from 75.39% to <31%. The antioxidant enzymes (SOD, CAT and GPx) activities in HepG2 cells were remarkably increased, with 12.5% and 25% Improved-FRDFD-dH2O demonstrating the greatest enhancing effects. RT-qPCR proved the betacyanins of Improved-FRDFD-dH2O possessed indirect antioxidant mechanisms, where the gene expressions associated with Nrf2-ARE pathway were upregulated by all the tested sample concentrations (highest fold: 6.82). Overall, the present findings highlighted the RDF's potential in functional product development with betacyanins as the prominent bioactive compound to provide direct and indirect antioxidative and hepatoprotective activities.

Molecular Crossfires between Inflammasome Signalling and Dietary Small Molecule Inhibitors in Neurodegenerative Diseases: Implications for Medical Nutrition Therapy

Neurodegenerative disorders are a range of debilitating conditions that manifest due to the progressive loss of neuronal cells in specific brain regions. Current therapeutic options are less than adequate in many respects. Protein misfolding and aggregation are hallmarks of the most common neurodegenerative disorders. Consequently, they elicit cellular homeostasis disruption, synaptic connection loss, and subsequent cellular apoptosis. In recent years, research has increasingly linked dysregulated inflammatory responses mediated by the inflammasome complex to several neurodegenerative conditions, such as Alzheimer's disease, Parkinson's disease, Epilepsy, Huntington’s disease, Autism, stroke etc. The inflammasome is a cytosolic multiprotein complex that is essential for innate immunity. Microglia are the primary cells expressing inflammasomes in the central nervous system, although astrocytes, neurons, and infiltrating myeloid cells can also express and activate inflammasomes. Regrettably, dysregulated inflammasome signaling upregulates the release of pro-inflammatory cytokines, as well as activating caspase-1. This process contributes to the continuation of neuroinflammation and subsequent damage to neurons. In this review of existing literatures, we collated empirical evidences about various inflammasome signaling pathways in selected neurological disorders. Majorly, we emphasised their influence on the advancement of diseases and neuronal cell death. Available empirical data showed that dietary small molecule inhibitors offer multi-targeted interactions to inhibit inflammasome signalling and upstream neuroinflammation. Notably, the baseline mechanisms involve suppression of free radicals, downregulating NF-κB and NLRP3 oligomerization, activating anti-inflammatory pathways, reducing ER stress, and modulating the Nrf2-ARE pathway. This shows promise for developing innovative medical nutrition therapies for various neurological conditions.

Ecklonia cava Polyphenols Have a Preventive Effect on Parkinson's Disease through the Activation of the Nrf2-ARE Pathway.

Parkinson's disease (PD) is a degenerative neurological disorder defined by the deterioration and loss of dopamine-producing neurons in the substantia nigra, leading to a range of motor impairments and non-motor symptoms. The underlying mechanism of this neurodegeneration remains unclear. This research examined the neuroprotective properties of Ecklonia cava polyphenols (ECPs) in mitigating neuronal damage induced by rotenone via the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway. Using human neuroblastoma SH-SY5Y cells and PD model mice, we found that ECP, rich in the antioxidant polyphenol phlorotannin, boosted the gene expression and functionality of the antioxidant enzyme NAD(P)H quinone oxidoreductase-1. ECP also promoted Nrf2 nuclear translocation and increased p62 expression, suggesting that p62 helps sustain Nrf2 activation via a positive feedback loop. The neuroprotective effect of ECP was significantly reduced by Compound C (CC), an AMP-activated protein kinase (AMPK) inhibitor, which also suppressed Nrf2 nuclear translocation. In PD model mice, ECPs improved motor functions impaired by rotenone, as assessed by the pole test and wire-hanging test, and restored intestinal motor function and colon tissue morphology. Additionally, ECPs increased tyrosine hydroxylase expression in the substantia nigra, indicating a protective effect on dopaminergic neurons. These findings suggest that ECP has a preventative effect on PD.

A Novel Protein Sourced from Chinese Medicine Residue for Golden Pompano Feed: Endothelium Corneum Gigeriae Galli Residue (ECGGR)

Fishmeal is an important protein source in aquafeed. However, due to the limited natural resources, fishmeal is in short supply, resulting in a price surge for fishmeal. Here, we reported a kind of Chinese medicine residue, endothelium corneum gigeriae galli residue (ECGGR), as a fishmeal substitute in the diets of Trachinotus ovatus. Six isonitrogenous and isolipidic diets were formulated, substituting fishmeal at 0%, 6.25%, 12.5%, 18.75%, 25%, and 31.25%. There was no significant difference in the growth performance when the fishmeal substitution level was no more than 25%. The smallest FCR was obtained at the 18.75% substitution level. Furthermore, substituting ECGGR for fishmeal had no effect on whole-body and muscle proximate compositions, except when the replacement level exceeded 25%, which led to a decrease in whole-body moisture and an increase in whole-body crude protein. The contents of Gly, Cys, Ile, Tyr, Pro, and EAAs/TAAs were altered as the substitution level varied. However, dietary replacement of fishmeal with ECGGR did not degrade muscle protein quality, according to a nutritional evaluation of muscle essential amino acid composition. In terms of hepatic antioxidant capacity, neither the overall antioxidant status nor the expression of genes in the Nrf2-ARE pathway was altered by dietary ECGGR. Moreover, the expressions of p65, TNF-α, and IL-8 in the intestine were upregulated at the 31.25% substitution level. Also, more goblet cells were observed in the intestine at substitution levels of 25% and 31.25%. In conclusion, ECGGR can substitute for fishmeal at the optimal level of 18.75% without adversely affecting the growth performance, protein quality, or hepatic and intestinal health of golden pompano.

Mangiferin Ameliorates CCl4-Triggered Acute Liver Injury by Inhibiting Inflammatory Response and Oxidative Stress: Involving the Nrf2-ARE Pathway.

Acute liver injury (ALI) is characterized by inflammation and oxidative stress (OS). Although mangiferin (MGF) has antioxidant and anti-inflammatory effects, its role in ALI remains unclear. Accordingly, we investigated the MGF molecular mechanism in carbon tetrachloride (CCl4)-induced ALI in vivo and in vitro. The CCl4 was utilized to induce ALI in mice. In vivo, the therapeutic effects of MGF on CCl4-induced liver injury were evaluated through biochemical assays and histomorphological analysis. Additionally, immunohistochemistry, immunofluorescence, ELISA and Western blotting were further applied to explore the mechanism. In vitro, The CCK-8 assay and flow cytometry were employed to investigate the protective effects of MGF against CCl4-induced toxicity in HepG2 cells, while mitochondrial reactive oxygen species levels and Western blotting were used to explore the biological effects and molecular mechanisms. MGF treatment resulted in a reduction in serum levels of AST and ALT, diminished concentrations of TNF-α, IL-6, and IL-1β in liver tissue, and concurrently decreased cellular apoptosis. Furthermore, MGF pretreatment enhanced the activity of SOD and GSH while concurrently diminishing the MDA production. This study further demonstrated the upregulation of Nrf2, NQO1, and HO-1 protein expression levels, as well as the downregulation of p-p65 protein expression levels. In vitro investigations revealed that the mitigation of CCl4-induced inflammation and OS by MGF was mediated via the Nrf2- antioxidant response element (ARE) pathway, which was disrupted by ML385 in HepG2 cells. CCl4 can induce liver injury, while treatment with MGF mitigates ALI by inhibiting oxidative stress, inflammation, and apoptosis. The protective mechanism of MGF is mediated by the Nrf2-ARE pathway activation.

Isolation and Purification of Harpagogenin as an Nrf2-ARE Activator from the Tubers of Chinese Artichoke (Stachys sieboldii).

Chinese artichoke tuber (Stachys sieboldii Miq.) is used as an herbal medicine as well as edible food. This study examined the effect of the Chinese artichoke extracts on the nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway that induces the expression of antioxidant enzymes to explore its novel characteristics. Hot water extracts exhibited relatively high ARE activity. ARE activity was observed in two fractions when the hot water extracts were separated in the presence of trifluoroacetic acid using HPLC. Conversely, the highly active fraction disappeared when the hot water extracts were separated in the absence of trifluoroacetic acid. These results indicate that acidic degradation produces active ingredients. The structural analysis of the two active fractions identified harpagide, which is an iridoid glucoside, and harpagogenin. In vitro experiments revealed that harpagide was converted into harpagogenin under acidic conditions and that harpagogenin, but not harpagide, had potent ARE activity. Therefore, this study identified harpagogenin, which is an acid hydrolysate of harpagide, as an ARE activator and suggests that Nrf2-ARE pathway activation by Chinese artichoke contributes to the antioxidative effect.

Unlocking the Potential: Novel NSAIDs Hybrids Unleash Chemopreventive Power toward Liver Cancer Cells through Nrf2, NF-κB, and MAPK Signaling Pathways.

HCC is a highly aggressive malignancy with limited treatment options. In this study, novel conjugates of non-steroidal anti-inflammatory drugs (NSAIDs)-Ibuprofen and Ketoprofen-with oleanolic acid oximes derivatives (OAO) were synthesized, and their activity as modulators of signaling pathways involved in HCC pathogenesis was evaluated in normal THLE-2 liver cells, and HCC-derived HepG2 cells. The results demonstrated that conjugation with OAO derivatives reduces the cytotoxicity of parent compounds in both cell lines. In THLE-2 cells, treatment with conjugates resulted in increased activation of the Nrf2-ARE pathway. An opposite effect was observed in HepG2 cells. In the later reduction of NF-κB, it was observed along with modulation of MAPK signaling pathways (AKT, ERK, p38, p70S6K, and JNK). Moreover, STAT3, STAT5, and CREB transcription factors on protein levels were significantly reduced as a result of treatment with IBU- and KET-OAO derivatives conjugates. The most active were conjugates with OAO-morpholide. Overall, the findings of this study demonstrate that IBU-OAO and KET-OAO derivative conjugates modulate the key signaling pathways involved in hepatic cancer development. Their effect on specific signaling pathways varied depending on the structure of the conjugate. Since the conjugation of IBU and KET with OAO derivatives reduced their cytotoxicity, the conjugates may be considered good candidates for the prevention of liver cancer.

The interaction of pterostilbene with Kelch-like ECH-associated protein 1 and its regulation on the nuclear factor erythroid 2-related factor 2/antioxidant response element pathway

Pterostilbene is a naturally occurring stilbene compound known for its anti-tumor effect. However, the molecular mechanism is still not explored well. Thus, the present work was designed to investigate the regulation effect of pterostilbene on the Nrf2-ARE pathway. The results of molecular docking showed that pterostilbene bound at the top of the central pore of the Keap1 Kelch domain, and the hydrogen bond and hydrophobic interactions were crucial for their stable binding. The western blot analysis confirmed that pterostilbene treatment promoted Nrf2 nuclear translocation. Reported gene assays confirmed the ARE luciferase activity of pterostilbene. RT-PCR and western blot assays showed that pterostilbene regulated the gene and protein expression of HO-1, NQO1, and GCLM. In vitro free radical scavenging assays have shown that pterostilbene can be effective in scavenging DPPH, ABTS, and hydroxyl radicals. In summary, pterostilbene activates the Nrf2-ARE pathway for exerting its bioactivities.

The effect of theabrownins on the amino acid composition and antioxidant properties of hen eggs

Pu-erh tea theabrownins (TBs) exert beneficial effect on egg quality and antioxidant properties of eggs, but the underlying mechanisms behind this response are unclear. In this study, we investigate the effect of TBs on egg antioxidative activity, amino acid and fatty acid profiles, and the underlying relationship between the TBs and oxidant-sensitive Nrf2 signaling pathway in laying hens. Eighty layers were fed a basal diet (control) and 400 mg/kg of TBs supplemented diet for 12 wk. TBs led to an increase in albumen height and Haugh unit (P < 0.05). The albumen lysine, valine, and tryptophan were higher in layers fed TBs, whereas yolk tryptophan, methionine, vitamin A, and α-tocopherol content were enhanced by TBs (P < 0.05). Eggs albumen and yolk showed higher total antioxidant capacity (T-AOC), reducing power (RP), and the scavenging rate of 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH), and lower MDA content than those of eggs from the control group (P < 0.05). Also, magnum Nrf2, hemeoxygenase 1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1), and Bcl2 expression were up-regulated by TBs, whereas magnum proapoptotic gene (Bax, caspase 3, Cyt C) were down-regulated by TBs (P < 0.05). Our findings suggest that TBs improved egg albumen quality and antioxidant activity, and the Nrf2-ARE pathway were found to be involved in this process.

Salidroside Attenuates Cisplatin-Induced Ototoxicity: An Experimental Study In Vitro and In Vivo

Oxidative damage to hair cells is the major cause of ototoxicity induced by cisplatin (cis)-based chemotherapy. In this study, we aimed to assess how salidroside (SAL) protected cochlear explants (CEs) and HEI-OC1 cell lines against cis-induced ototoxicity and reduced relative hearing loss in mouse models. Furthermore, the protective mechanism of the Nrf2/ARE pathway was investigated. Cell Counting Kit-8 was used to measure the viability of HEI-OC1 cells. Flow cytometry and the TUNEL assay were used to evaluate cell apoptosis. Flow cytometry was used to measure intracellular reactive oxygen species (ROS). Immunofluorescence staining determined the changes in mitochondrial membrane potential (ΔΨm). Western blot was used to measure the levels of caspase-3 and Nrf-2. An analysis of Nrf2 and target gene levels of expression was conducted using qRT-PCR. Hearing was monitored using auditory brainstem response audiometry. In cochlear explants, SAL inhibits cis-induced apoptosis of HEI-OC1 cells and decreased hair cell apoptosis. SAL inhibited cis-induced apoptosis by lowering intracellular ROS, preserving mitochondrial function, and reducing caspase-3 expression. Moreover, auditory cells were protected from the toxic effects of cis by the Nrf2-ARE pathway after treatment with SAL. In Vivo, SAL could protect against cis-induced hearing loss, and the use of the PLGA-poloxamer nanohydrogel as a carrier increased the protection efficiency of SAL. Through its ability to reduce oxidative stress, SAL could protect auditory cell lines from cis-induced apoptosis In Vitro and attenuate cis-induced hearing loss In Vivo. Nano-based drug delivery can improve the protection efficiency of SAL. Further research should be conducted on the antioxidant capacity of SAL and its use in ototoxicity.

Delivery of Transcriptional Factors for Activating Antioxidant Defenses against Inflammatory Bowel Disease.

Oxidative stress caused by the overproduction of reactive oxygen species (ROS) plays an important role in inflammatory bowel disease (IBD). It is well-known that the Nrf2-ARE (antioxidative response element) pathway is important in the regulation mechanism of antioxidant defense. Therefore, Nrf2 activation may be an effective therapeutic strategy for IBD. Here, we reported the development of a nucleus-targeted Nrf2 delivery nanoplatform, termed N/LC, that could accumulate in inflamed colonic epithelium, reduce inflammatory responses, and restore epithelium barriers in a murine model of acute colitis. N/LC nanocomposites could quickly escape from lysosomes, so Nrf2 largely accumulated in the nucleus of colonic cells, activated the Nrf2-ARE signaling pathway, further elevated the expression levels of downstream detoxification and antioxidant genes, and protected cells from oxidative damage. These results suggested that N/LC might be a potential nanoplatform for IBD therapy. The study provided the basis for the biomedical applications of Nrf2-based therapeutics in various diseases.

Short-term exposure to dimethyl fumarate (DMF) inhibits LPS-induced IκBζ expression in macrophages.

Background: The pharmacological activity of dimethyl fumarate (DMF) in treating psoriasis and multiple sclerosis (MS) is not fully understood. DMF is hydrolysed to monomethyl fumarate (MMF) in vivo, which is believed to account for the therapeutic effects of DMF. However, previous studies have provided evidence that DMF also enters the circulation. Given that DMF is short-lived in the blood, whether DMF has a therapeutic impact is still unclear. Methods: Lipopolysaccharide (LPS)-mediated RAW264.7 cell activation was used as a model of inflammation to explore the anti-inflammatory effects of short-term DMF exposure in vitro. Whole blood LPS stimulation assay was applied to compare the anti-inflammatory effects of DMF and MMF in vivo. Griess assay was performed to examined nitrite release. The expression of pro-inflammatory cytokines and transcription factors were measured by quantitative PCR (qPCR), ELISA and Western blot. Depletion of intracellular glutathione (GSH) was evaluated by Ellman's assay. Luciferase reporter assays were performed to evaluate DMF effects on Nrf2-ARE pathway activation, promoter activity of Nfkbiz and mRNA stability of Nfkbiz. Binding of STAT3 to the IκBζ promoter were examined using Chromatin immunoprecipitation (ChIP) assay. Results: Short-term exposure to DMF significantly inhibited the inflammatory response of RAW264.7 cells and suppressed LPS-induced IκBζ expression. Importantly, oral DMF but not oral MMF administration significantly inhibited IκBζ transcription in murine peripheral blood cells. We demonstrated that the expression of IκBζ is affected by the availability of intracellular GSH and regulated by the transcription factor Nrf2 and STAT3. DMF with strong electrophilicity can rapidly deplete intracellular GSH, activate the Nrf2-ARE pathway, and inhibit the binding of STAT3 to the IκBζ promoter, thereby suppressing IκBζ expression in macrophages. Conclusion: These results demonstrate the rapid anti-inflammatory effects of DMF in macrophages, providing evidence to support the direct anti-inflammatory activity of DMF.

The Regulatory Effect of Phytochemicals on Chronic Diseases by Targeting Nrf2-ARE Signaling Pathway

Redox balance is essential to maintain the body's normal metabolism. Once disrupted, it may lead to various chronic diseases, such as diabetes, neurodegenerative diseases, cardiovascular diseases, inflammatory diseases, cancer, aging, etc. Oxidative stress can cause or aggravate a series of pathological processes. Inhibition of oxidative stress and related pathological processes can help to ameliorate these chronic diseases, which have been found to be associated with Nrf2 activation. Nrf2 activation can not only regulate the expression of a series of antioxidant genes that reduce oxidative stress and its damage, but also directly regulate genes related to the above-mentioned pathological processes to counter the corresponding changes. Therefore, targeting Nrf2 has great potential for the prevention or treatment of chronic diseases, and many natural phytochemicals have been reported as Nrf2 activators although the defined mechanisms remain to be elucidated. This review article focuses on the possible mechanism of Nrf2 activation by natural phytochemicals in the prevention or treatment of chronic diseases and the regulation of oxidative stress. Moreover, the current clinical trials of phytochemical-originated drug discovery by targeting the Nrf2-ARE pathway were also summarized; the outcomes or the relationship between phytochemicals and chronic diseases prevention are finally analyzed to propose the future research strategies and prospective.

Characterization of tangeretin as an activator of nuclear factor erythroid 2-related factor 2/antioxidant response element pathway in HEK293T cells

Numerous studies have reported that tangeretin is a polymethoxylated flavone with a variety of biological activates, but little research has been done on the antioxidant mechanism of tangeretin. Hence, we investigated the effect of tangeretin on the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway and its potential molecular mechanisms by in vitro and in silico research. The results of molecular docking suggested that tangeretin bound at the top of the central pore of Kelch-like ECH-associated protein 1 (Keap1) Kelch domain, and the hydrophobic and hydrogen bond interactions contributed to their stable binding. Herein, the regulation of Nrf2-ARE pathway by tangeretin was explored in the human embryonic kidney cell line HEK293T, which is relatively easy to be transfected. Upon binding to tangeretin, Nrf2 translocated to the nucleus of HEK293T cells, which in turn activated the Nrf2-ARE pathway. Luciferase reporter gene analysis showed that tangeretin significantly induced ARE-mediated transcriptional activation. Real-time PCR and Western blot assays showed that tangeretin induced the gene and protein expressions of Nrf2-mediated targets, including heme oxygenase 1 (HO-1), nicotinamide adenine dinucleotide phosphate (NADPH) quinone dehydrogenase 1 (NQO1), and glutamate-cysteine ligase (GCLM). In addition, tangeretin could effectively scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. In summary, tangeretin may be a potential antioxidant via activating the Nrf2-ARE pathway.

Potential Cytoprotective and Regulatory Effects of Ergothioneine on Gene Expression of Proteins Involved in Erythroid Adaptation Mechanisms and Redox Pathways in K562 Cells

This study aimed to establish the importance of ergothioneine (ERT) in the erythroid adaptation mechanisms by appraising the expression levels of redox-related genes associated with the PI3K/AKT/FoxO3 and Nrf2-ARE pathways using K562 cells induced to erythroid differentiation and H2O2-oxidative stress. Cell viability and gene expression were evaluated. Two concentrations of ERT were assessed, 1 nM (C1) and 100 µM (C2), with and without stress induction (100 µM H2O2). Assessments were made in three periods of the cellular differentiation process (D0, D2, and D4). The C1 treatment promoted the induction of FOXO3 (D0 and 2), PSMB5, and 6 expressions (D4); C1 + H2O2 treatment showed the highest levels of NRF2 transcripts, KEAP1 (D0), YWHAQ (D2 and 4), PSMB5 (D2) and PSMB6 (D4); and C2 + H2O2 (D2) an increase in FOXO3 and MST1 expression, with a decrease of YWHAQ and NRF2 was observed. in C2 + H2O2 (D2) an increase in FOXO3 and MST1, with a decrease in YWHAQ and NRF2 was observed All ERT treatments increased gamma-globin expression. Statistical multivariate analyzes highlighted that the Nrf2-ARE pathway presented a greater contribution in the production of PRDX1, SOD1, CAT, and PSBM5 mRNAs, whereas the PI3K/AKT/FoxO3 pathway was associated with the PRDX2 and TRX transcripts. In conclusion, ERT presented a cytoprotective action through Nrf2 and FoxO3, with the latter seeming to contribute to erythroid proliferation/differentiation.

Influence of Melatonin Treatment on Cellular Mechanisms of Redox Adaptation in K562 Erythroleukemic Cells

Melatonin (MEL) presents well-documented pleiotropic actions against oxidative stress (OS), acting indirectly through activation of transcription factors, e.g., FoxO3 and Nrf2. Thus, this study aimed to investigate the possible modulating effects of MEL on the redox signaling pathways PI3K/AKT/FoxO3 and Keap1/Nrf2/ARE in K562 erythroleukemic cells subjected to OS induction. For this, the viability, and transcript levels of genes involved in redox adaptation were evaluated in K562 cells in different periods of erythroid differentiation: under OS induction by hydrogen peroxide (100 µM H2O2); treated with 1 nM (C1) and 1 mM (C2) MEL; and associated or not with stress induction. We observed a restoration of physiological levels of Nrf2 in both MEL concentrations under OS. The C1 was related to enhanced expression of antioxidant and proteasome genes through the Nrf2-ARE pathway, while C2 to the induction of FOXO3 expression, suggesting an involvement with apoptotic pathway, according to BIM transcript levels. The effects of MEL administration in these cells showed a period and dose-dependent pattern against induced-OS, with direct and indirect actions through different pathways of cellular adaptation, reinforcing the importance of this indolamine in the regulation of cellular homeostasis, being a promising therapeutic alternative for diseases that present an exacerbated OS.

Abamectin causes cardiac dysfunction in carp via inhibiting redox equilibrium and resulting in immune inflammatory response and programmed cell death.

This study aims to investigate the effects of environmentally relevant concentrations of abamectin on the cardiac function of carp and the potential mechanisms. Here, male carp were exposed to abamectin, and cardiac function-related enzymatic markers were examined. Cardiac histopathology, redox equilibrium, inflammation, and cell death were evaluated. Abamectin exposure caused cardiac dysfunction by upregulating lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatine kinase (CK), creatine Kinase MB isoenzyme (CK-MB) and white blood cells (WBCs), and decreasing red blood cells (RBCs) and hemoglobin (Hb). DHE staining and biochemical assays revealed that abamectin caused ROS release and oxidative stress by inhibiting Nrf2-ARE pathway. Histopathological and real-time fluorescence quantitative PCR (RT-qPCR) assays revealed that abamectin caused myocardial fiber swelling and inflammatory cell infiltration, enhanced pro-inflammatory cytokines tumor necrosis factor-α (Tnf-α), interleukin-1 beta (Il-1β), and Il-6 levels and attenuated anti-inflammatory cytokines Il-10 and transforming growth factor beta 1 (Tgf-β1) through activating NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome and nuclear factor kappa-B (NF-κB) pathway. Tunel staining showed that abamectin triggered cardiac apoptosis via activating p53-mediated mitochondrial apoptosis with elevated bcl2-associated X (Bax), reduced B-cell lymphoma-2 (Bcl-2), and activated Caspase-9 and Caspase-3. Immunoblot analysis revealed that abamectin activated autophagic flow by inhibiting mammalian target of rapamycin (mTOR), resulting in the conversion of LC3B from LC3-I to LC3-II, elevation of autophagy protein 5 (Atg5), and reduction of p62. Overall, abamectin caused cardiac dysfunction in carp via inhibiting redox equilibrium and resulting in immune inflammatory response and programmed cell death.

Protective effects of cyanidin-3-O-glucoside on BPA-induced neurodevelopmental toxicity in zebrafish embryo model

Bisphenol A (BPA) is ubiquitous in the environment and poses a threat to wildlife and human health. It has been reported that BPA may cause the neurotoxicity during gestational and neonatal periods. Cyanidin-3-O-glucoside (C3G) is one of the most abundant anthocyanins that has shown multiple bio-functions. In this study, the protective effects and possible mechanism of C3G against BPA-induced neurodevelopment toxicity in zebrafish embryos/larvae were studied. The results showed that co-exposure of C3G (25 μg/mL) significantly attenuated BPA-induced deficit in locomotor behavior and restored the BPA-induced aberrant changes in brain morphology of zebrafish larvae. Further studies showed that the defects of central nervous development and the downregulated neurogenesis relative genes induced by BPA were significantly counteracted by co-exposure with 5 μg/mL of C3G. In addition, C3G (25 μg/mL) mitigated the decline of glutathione (GSH) content and enzymatic activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT), attenuated oxidative stress and cell apoptosis induced by BPA in zebrafish. The enhancements of the expression of genes involved in the Nrf2-ARE pathway (Nrf2, HO-1, NQO1, GCLC, and GCLM) were also observed by co-exposure of C3G. The results indicate that C3G exerts protective effects on BPA-induced neurodevelopmental toxicity through improving transcription of neurogenesis related genes, enhancing antioxidative defense system and reducing cell apoptosis by regulation of apoptotic genes in zebrafish larvae. The results suggest that anthocyanins may play important role against the exogenous toxicity for vertebrates.