Dioscin exerts nephroprotective effects by attenuating oxidative stress and necroptosis-induced inflammation.

Acute kidney injury (AKI) is a syndrome characterized by the rapid loss of the renal function and has high morbidity and mortality worldwide, yet there is no satisfactory means of prevention and treatment at present. Dioscin, a natural steroidal saponin, has been found to have antioxidant, anti-inflammatory and anti-apoptotic effects. In this experiment, we pretreated cisplatin-induced AKI rats with dioscin and found that dioscin significantly enhanced renal function and reduced renal pathological injury in AKI rats. We also found that dioscin improved renal antioxidant capacity by suppressing the accumulation of oxides such as ROS, MDA and H2O2, and increasing the levels of antioxidant enzymes SOD and CAT. In addition, dioscin down-regulated the expression of inflammation-related proteins (IL-1ß, TNF-α, NF-κB) and necroptosis-critical proteins RIP1/RIP3, whereas up-regulated Caspase-8 protein levels in the kidney of AKI rats. Mechanistically, dioscin promoted the nuclear transcription of Nrf2 and activated Nrf2/HO-1 signaling axis to play a positive role in the kidney of AKI rats, while the reno-protective effect of dioscin was significantly attenuated after inhibiting Nrf2. In conclusion, our data indicate that dioscin decreases cisplatin-induced renal oxidative stress and thwarts necroptosis induced inflammation via regulating the Nrf2/HO-1pathway. Our study provides more data and theoretical support for the study of natural drugs to improve AKI.

Astragaloside IV attenuates ferroptosis and protects against iron overload-induced retinal injury.

Retinal injury may be exacerbated by iron overload. Astragaloside IV (AS-IV) has potential applications in the food and healthcare industry to promote eye health. We sought to determine the mechanisms responsible for the protective effects of AS-IV on photoreceptor and retinal pigment epithelium cell death induced by iron overload. We conducted in vitro and in vivo experiments involving AS-IV pretreatment. We tested AS-IV for its ability to protect iron-overload mice from retinal injury. In particular, we analyzed the effects of AS-IV on iron overload-induced ferroptosis in 661W and ARPE-19 cells. AS-IV not only attenuated iron deposition and retinal injury in iron-overload mice but also effectively reduced iron overload-induced ferroptotic cell death in 661W and ARPE-19 cells. AS-IV effectively prevented ferroptosis by inhibiting iron accumulation and lipid peroxidation. In addition, inhibiting nuclear factor erythroid 2-related factor 2 (Nrf2) eliminated the protective effect of AS-IV against ferroptosis. The results suggest that ferroptosis might be a significant cause of retinal cell death associated with iron overload. AS-IV provides protection from iron overload-induced ferroptosis, partly by activating the Nrf2 signaling pathway.

Nrf2 as a regulator of energy metabolism and mitochondrial function.

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

Nrf2 cell signaling pathway is responsible for the antioxidant effect of resveratrol in aging.

INTRODUCTION: One of the markers of aging is oxidative stress, a condition characterized by an increase in free radicals concomitant with a reduction in antioxidant defenses. Within this, resveratrol is a compound that has been shown to act as a potent antioxidant. However, few studies highlight the cellular signaling pathways that are activated or inhibited during aging and that are responsible for this biological effect. AIM: To verify the antioxidant profile of resveratrol (5 µM) in leukocytes from donors in different age groups. METHODS: The project was approved by the Ethics Committee. Individuals were divided into three groups: 20-39, 40-59, and 60-80 years old. After separating the leukocytes, assays were performed to evaluate the AMPK (AMP-activated protein kinase) and Nrf2 (erythroid nuclear factor 2-related factor 2) pathways. In addition, luciferase assay and enzyme-linked immunosorbent assay were performed to evaluate transcription factor activation and Nrf2 expression, respectively. The analysis between age and treatment was performed using Pearson correlation (*P < 0.05). RESULTS: There was a reduction in the antioxidant effect of resveratrol during the aging process. In leukocytes from donors over 60 years of age, the AMPK pathway was silenced. Nrf2 was active at all ages. There was an increase in the activation of the transcription factor and phosphorylated protein in all age groups. CONCLUSIONS: Nrf2 is an important biochemical mechanism responsible for the antioxidant effect of resveratrol. This effect diminishes with aging but is still observed. Geriatr Gerontol Int 2024; ••: ••-••.

Wedelolactone inhibits ferroptosis and alleviates hyperoxia-induced acute lung injury via the Nrf2/HO-1 signaling pathway.

Hyperoxia-induced acute lung injury (HALI) is a complication of oxygen therapy. Ferroptosis is a vital factor in HALI. This paper was anticipated to investigate the underlying mechanism of Wedelolactone (WED) on ferroptosis in HALI. The current study used hyperoxia to injure two models, one HALI mouse model and one MLE-12 cell injury model. We found that WED treatment attenuated HALI by decreasing the lung injury score and lung wet/dry weight ratio and alleviating pathomorphological changes. Then, the inflammatory reaction and apoptosis in HALI mice and hyperoxia-mediated MLE-12 cells were inhibited by WED treatment. Moreover, WED alleviated ferroptosis with less iron accumulation and reversed expression alterations of ferroptosis markers, including MDA, GSH, GPX4, SLC7A11, FTH1, and TFR1 in hyperoxia-induced MLE-12 cells in vitro and in vivo. Nrf2-KO mice and Nrf2 inhibitor (ML385) decreased WED's ability to protect against apoptosis, inflammatory response, and ferroptosis in hyperoxia-induced MLE-12 cells. Collectively, our data highlighted the alleviatory role of WED in HALI by activating the Nrf2/HO-1 pathway.

Phenylpropanoid-rich maize root extract serves as a natural antidepressant.

BACKGROUND: Depression is a serious and complex mental disease that has attracted worldwide attention because of its high incidence rate, high disability rate and high mortality. Excitotoxicity is one of the most important mechanisms involved in the pathophysiological process of depression. In our previous studies, n-butanol extract from maize roots was found to have good neuroprotective effects due to its antioxidative activity. However, the antidepressive effective constituents, efficacy in vivo and mechanism of action of maize root extracts have not been determined. PURPOSE: This study aimed to determine the main active neuroprotective compound in maize root extract and investigate its antidepressant effects and possible underlying mechanism in vitro and in vivo. METHODS: Sixteen extracts were isolated and purified from maize roots. The active components of the most active extracts of maize roots (hereafter referred to as EM 2) were identified using UF-HPLC-QTOF/MS. In vitro cell models of NMDA-induced excitotoxicity in SH-SY5Y cells were used to analyze the anti-excitatory activity of the extracts. The MTT assay and Annexin V-FITC/PI Apoptosis Detection were used to evaluate cell viability. Several network pharmacological strategies have been employed to investigate the potential mechanism of action of EM 2. The effects of EM 2 on depressive-like behaviors were evaluated in CUMS mice. Changes in the levels of related proteins were detected via western blotting. RESULTS: Among the 16 extracts extracted by n-butanol, EM 2 was determined to be the most active extract against NMDA-induced excitotoxicity by n-butanol extraction. Meanwhile, seventeen compounds were further identified as the main active components of EM 2. Mechanistically, EM 2 inhibited NMDA-induced excitatory injury in SH-SY5Y cells and alleviated the depressive-like behaviors of CUMS mice by suppressing NR2B and subsequently mediating the downstream CREB/TRKB/BDNF, PI3K/Akt and MAPK pathways, as well as the Nrf2/HO-1 antioxidant signaling pathway. CONCLUSION: The study indicated that EM 2 could potentially be developed as a potential therapeutic candidate to cure depression in NMDA-induced excitatory damage.

NRF2-HIF2α Signaling Attenuates Endothelial Cell Senescence and Maintains Intercellular Junctions in Diabetes.

In the context of diabetes, endothelial cells frequently exhibit compromised intercellular junctions and accelerated cellular senescence simultaneously. The precise mechanisms underlying these issues and the identification of effective treatments remain largely undefined. Our findings reveal that human umbilical vein endothelial cells (HUVECs) can counteract senescence and uphold the integrity of intercellular junctions under mildly to moderately elevated glucose levels (10 mM and 15 mM) via two primary mechanisms: i) The acetylation of NRF2 at lysine residues K56, K68, and K52 prevents its ubiquitination, enhancing the transcription of antioxidant genes GST, SOD1, and GPX1. This activity diminishes cytoplasmic oxidative stress, thereby mitigating endothelial cell senescence. ii) The interaction between the Neh2 domain of NRF2 and the PAS-B domain of HIF-2α within the nucleus curtails the attachment of HIF-2α to the NOX4/p22phox promoter. This action lessens oxidative stress near the cell membrane, maintaining intercellular junctions by safeguarding the disulfide bonds in occludin and E-cadherin from disruption. However, these protective strategies prove insufficient under severe hyperglycemic conditions (25 mM). Further investigation has identified Oltipraz, an activator of NRF2, as also promoting the degradation of HIF-2α. Through its simultaneous modulation of NRF2 and HIF-2α, Oltipraz significantly reduces cellular senescence and prevents the deterioration of intercellular junctions in HUVECs subjected to high glucose concentrations (25 mM). Our research positions Oltipraz as a promising therapeutic candidate for mitigating diabetes-induced vascular endothelial damage, potentially offering benefits against diabetes-related atherosclerosis and valvular calcification.

Targeting the NRF2 pathway for disease modification in neurodegenerative diseases: mechanisms and therapeutic implications.

Neurodegenerative diseases constitute a global health issue and a major economic burden. They significantly impair both cognitive and motor functions, and their prevalence is expected to rise due to ageing societies and continuous population growth. Conventional therapies provide symptomatic relief, nevertheless, disease-modifying treatments that reduce or halt neuron death and malfunction are still largely unavailable. Amongst the common hallmarks of neurodegenerative diseases are protein aggregation, oxidative stress, neuroinflammation and mitochondrial dysfunction. Transcription factor nuclear factor-erythroid 2-related factor 2 (NRF2) constitutes a central regulator of cellular defense mechanisms, including the regulation of antioxidant, anti-inflammatory and mitochondrial pathways, making it a highly attractive therapeutic target for disease modification in neurodegenerative disorders. Here, we describe the role of NRF2 in the common hallmarks of neurodegeneration, review the current pharmacological interventions and their challenges in activating the NRF2 pathway, and present alternative therapeutic approaches for disease modification.

Sex Differences Affect the NRF2 Signaling Pathway in the Early Phase of Liver Steatosis: A High-Fat-Diet-Fed Rat Model Supplemented with Liquid Fructose.

Sex differences may play a role in the etiopathogenesis and severity of metabolic dysfunction-associated steatotic liver disease (MASLD), a disorder characterized by excessive fat accumulation associated with increased inflammation and oxidative stress. We previously observed the development of steatosis specifically in female rats fed a high-fat diet enriched with liquid fructose (HFHFr) for 12 weeks. The aim of this study was to better characterize the observed sex differences by focusing on the antioxidant and cytoprotective pathways related to the KEAP1/NRF2 axis. The KEAP1/NRF2 signaling pathway, autophagy process (LC3B and LAMP2), and endoplasmic reticulum stress response (XBP1) were analyzed in liver homogenates in male and female rats that were fed a 12-week HFHFr diet. In females, the HFHFr diet resulted in the initial activation of the KEAP1/NRF2 pathway, which was not followed by the modulation of downstream molecular targets; this was possibly due to the increase in KEAP1 levels preventing the nuclear translocation of NRF2 despite its cytosolic increase. Interestingly, while in both sexes the HFHFr diet resulted in an increase in the levels of LC3BII/LC3BI, a marker of autophagosome formation, only males showed a significant upregulation of LAMP2 and XBP1s; this did not occur in females, suggesting impaired autophagic flux in this sex. Overall, our results suggest that males are characterized by a greater ability to cope with an HFHFr metabolic stimulus mainly through an autophagic-mediated proteostatic process while in females, this is impaired. This might depend at least in part upon the fine modulation of the cytoprotective and antioxidant KEAP1/NRF2 pathway resulting in sex differences in the occurrence and severity of MASLD. These results should be considered to design effective therapeutics for MASLD.

Impairment of Nrf2 signaling in the hippocampus of P301S tauopathy mice model aligns with the cognitive impairment and the associated neuroinflammation.

Mice transgenic for human P301S tau protein exhibit many characteristics of the human tauopathies, including the formation of abundant hyperphoshorylated tau filaments, the associated neuroinflammation and disease phenotype. However, the exact underpinning mechanisms are still not fully addressed that hinder our understanding of the tauopathy diseases and the development of possible therapeutic targets.Methods: In the current study, hippocampus from three disease time points (2, 4 and 6 months) of P301S mice were further characterized in comparison to the age and sex matched control wild type mice (WT) that do not express the transgene. Different spectrum of hippocampal dependent cognitive tests, biochemical and pathological analysis were conducted to understand the disease progression and the associated changes in each stage. Results: Cognitive impairment was manifested as early as 2 months age, prior to the identification of tau aggregation and phosphorylation by immunostaining. P301S mice manifested an increased pro-inflammatory related changes at mRNA transcription level (IL-1b and IL17A) with the progression of the disease and when compared to the WT mice of the same age. Among the identified genes in the current study, the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) genes expression that is considered as the master regulator of an endogenous inducible defense system was significantly impaired in P301S mice by 4 and 6 months when compared to healthy WT controls. A data that was also supported by the immunostaining of the serial brain sections including the both brain stem and hippocampus. The current result is suggesting that the downregulation of Nrf2 gene and the impaired Nrf2 dependent anti-inflammatory mechanisms in P301S mice brain is possibly contributing -among other factors- in the neuroinflammation and tauopathy, and that modulation of Nrf2 signaling impairments can be further investigated as a promising potential therapeutic target for tauopathy.

Exosomal circ-0100519 promotes breast cancer progression via inducing M2 macrophage polarisation by USP7/NRF2 axis.

BACKGROUND: Breast cancer (BC) is one of the most prevalent malignant tumours that threatens women health worldwide. It has been reported that circular RNAs (circRNAs) play an important role in regulating tumour progression and tumour microenvironment (TME) remodelling. METHODS: Differentially expression characteristics and immune correlations of circRNAs in BC were verified using high-throughput sequencing and bioinformatic analysis. Exosomes were characterised by nanoparticle transmission electron microscopy and tracking analysis. The biological function of circ-0100519 in BC development was demonstrated both in vitro and in vivo. Western blotting, RNA pull-down, RNA immunoprecipitation, flow cytometry, and luciferase reporter were conducted to investigate the underlying mechanism. RESULTS: Circ-0100519 was significant abundant in BC tumour tissues and related to poor prognosis. It can be encapsulated into secreted exosomes, thereby promoting BC cell invasion and metastasis via inducing M2-like macrophages polarisation.Mechanistically, circ-0100519 acted as a scaffold to enhance the interaction between the deubiquitinating enzyme ubiquitin-specific protease 7 (USP7) and nuclear factor-like 2 (NRF2) in macrophages, inducing the USP7-mediated deubiquitination of NRF2. Additionally, HIF-1α could function as an upstream effector to enhance circ-0100519 transcription. CONCLUSIONS: Our study revealed that exosomal circ-0100519 is a potential biomarker for BC diagnosis and prognosis, and the HIF-1α inhibitor PX-478 may provide a therapeutic target for BC.

Epigenetic repression of de novo cysteine synthetases induces intra-cellular accumulation of cysteine in hepatocarcinoma by up-regulating the cystine uptake transporter xCT.

BACKGROUND: The metabolic reprogramming of amino acids is critical for cancer cell growth and survival. Notably, intracellular accumulation of cysteine is often observed in various cancers, suggesting its potential role in alleviating the oxidative stress associated with rapid proliferation. The liver is the primary organ for cysteine biosynthesis, but much remains unknown about the metabolic alterations of cysteine and their mechanisms in hepatocellular carcinoma cells. METHODS: RNA-seq data from patients with hepatocarcinoma were analyzed using the TNMplot database. The underlying mechanism of the oncogenic alteration of cysteine metabolism was studied in mice implanted with BNL 1ME A.7 R.1 hepatocarcinoma. RESULTS: Database analysis of patients with hepatocellular carcinoma revealed that the expression of enzymes involved in de novo cysteine synthesis was down-regulated accompanying with increased expression of the cystine uptake transporter xCT. Similar alterations in gene expression have also been observed in a syngeneic mouse model of hepatocarcinoma. The enhanced expression of DNA methyltransferase in murine hepatocarcinoma cells caused methylation of the upstream regions of cysteine synthesis genes, thereby repressing their expression. Conversely, suppression of de novo cysteine synthesis in healthy liver cells induced xCT expression by up-regulating the oxidative-stress response factor NRF2, indicating that reduced de novo cysteine synthesis repulsively increases cystine uptake via enhanced xCT expression, leading to intracellular cysteine accumulation. Furthermore, the pharmacological inhibition of xCT activity decreased intracellular cysteine levels and suppressed hepatocarcinoma tumor growth in mice. CONCLUSIONS: Our findings indicate an underlying mechanism of the oncogenic alteration of cysteine metabolism in hepatocarcinoma and highlight the efficacy of alteration of cysteine metabolism as a viable therapeutic target in cancer.

Nrf2 Signaling Pathway: Focus on Oxidative Stress in Spinal Cord Injury.

Spinal cord injury (SCI) is a serious, disabling injury to the central nervous system that can lead to motor, sensory, and autonomic dysfunction below the injury plane. SCI can be divided into primary injury and secondary injury according to its pathophysiological process. Primary injury is irreversible in most cases, while secondary injury is a dynamic regulatory process. Secondary injury involves a series of pathological events, such as ischemia, oxidative stress, inflammatory events, apoptotic pathways, and motor dysfunction. Among them, oxidative stress is an important pathological event of secondary injury. Oxidative stress causes a series of destructive events such as lipid peroxidation, DNA damage, inflammation, and cell death, which further worsens the microenvironment of the injured site and leads to neurological dysfunction. The nuclear factor erythrocyte 2-associated factor 2 (Nrf2) is considered to be a key pathway of antioxidative stress and is closely related to the pathological process of SCI. Activation of this pathway can effectively inhibit the oxidative stress process and promote the recovery of nerve function after SCI. Therefore, the Nrf2 pathway may be a potential therapeutic target for SCI. This review deeply analyzed the generation of oxidative stress in SCI, the role and mechanism of Nrf2 as the main regulator of antioxidant stress in SCI, and the influence of cross-talk between Nrf2 and related pathways that may be involved in the pathological regulation of SCI on oxidative stress, and summarized the drugs and other treatment methods based on Nrf2 pathway regulation. The objective of this paper is to provide evidence for the role of Nrf2 activation in SCI and to highlight the important role of Nrf2 in alleviating SCI by elucidating the mechanism, so as to provide a theoretical basis for targeting Nrf2 pathway as a therapy for SCI.

Water extract of earthworms mitigates kidney injury triggered by oxidative stress via activating intrarenal Sirt1/Nrf2 cascade and ameliorating mitochondrial damage.

ETHNOPHARMACOLOGICAL RELEVANCE: Ischemia-reperfusion (IR) injury can result in acute renal failure. Oxidative stress is a major factor in IR-induced cell death in the kidneys. According to traditional Chinese medicine, earthworms (Pheretima aspergillum) can be used to treat various kidney diseases. AIM OF THE STUDY: The present study was designed to understand the protective effects of the water extract of earthworms (WEE) against oxidative stress on the kidneys and the crucial molecular events associated with its nephroprotective activity. MATERIALS AND METHODS: Cytotoxicity caused by H2O2 in HEK293, HK2, and primary mouse renal tubular epithelial cells (TECs) was used to investigate the effect of WEE on oxidative stress-induced renal injury in vitro. IR-induced kidney injury was established using rats as an in vivo model. The WEE-mediated protection of the kidneys against oxidative stress was compared with that of glutathione, a common antioxidant used as a positive control. RESULTS: In HEK293 cells, HK2 cells, and primary mouse TECs, WEE relieved H2O2-induced mitochondrial damage, apoptosis, and ferroptosis. In kidney cells, WEE increased the expression of Sirt1, boosted LKB1 and AMPK phosphorylation, and upregulated nuclear Nrf2. Suppression of Sirt1 and LKB1 knock down abrogated WEE-induced protection against H2O2. WEE ameliorated IR-induced kidney injury and intrarenal inflammation in rats. In rat kidneys, WEE mitigated mitochondrial damage and suppressed IR-induced apoptosis and ferroptosis. Mechanistically, WEE increased Sirt1 expression, enhanced the phosphorylation of LKB1 and AMPK, and increased intranuclear Nrf2 levels in IR kidneys. IR treatment resulted in considerable increase in renal MDA levels and a prominent decrease in antioxidative enzyme activity. These lesions were significantly alleviated by WEE. CONCLUSIONS: WEE mitigated H2O2-induced cytotoxicity in kidney cells in vitro and improved IR-induced kidney damage in rats. Mechanistically, WEE potentiated the Sirt1/Nrf2 axis and relieved mitochondrial damage in the kidney cells. These events inhibited the apoptosis and ferroptosis induced by oxidative stress. Our findings support the potential application of WEE for the clinical treatment of kidney diseases caused by intrarenal oxidative stress.

Gui Qi Zhuang Jin Decoction ameliorates mitochondrial dysfunction in sarcopenia mice via AMPK/PGC-1α/Nrf2 axis revealed by a metabolomics approach.

OBJECTIVE: Sarcopenia, as a condition of muscle mass loss and functional decline typically diagnosed in elderly individuals, severely affects human physical activity, metabolic homeostasis, and quality of life. Gui Qi Zhuang Jin Decoction (GQZJD), an approved hospital-based prescription with years of clinical application, has been demonstrated to have a notable therapeutic effect on sarcopenia. However, its potential mechanism of action in the treatment of sarcopenia remains uncertain. METHODS: Ultra-performance liquid chromatography paired with Q Exactive™ HF-X mass spectrometry (UPLC-QE-MS) was used to identify the ingredients of GQZJD. Subsequently, GQZJD observed the basic growth and muscles of the sarcopenia mouse, while the behavioral indicators were also tested. Muscle histopathology and serum oxidative stress biochemicals were also detected, and mitochondrial function and energy metabolism-related indicators in the gastrocnemius muscle were examined. Then, a metabolomics strategy was applied to predict possible pathways involving mitochondria by which GQZJD could improve sarcopenia. Finally, quantitative real-time polymerase chain reaction and western blot analyses were carried out to validate the effects of GQZJD on sarcopenia-induced mitochondrial dysfunction, together with uncovering the associated mechanisms. RESULTS: Twenty-seven ingredients absorbed into the blood (IAIBs) of GQZJD were identified using UPLC-QE-MS, which were regarded as the main active ingredients behind its sarcopenia treatment effects. GQZJD administration increased the body weight, gastrocnemius muscle mass, and autonomic activity, mitigated muscle tissue morphology and pathology; and alleviated the oxidative stress levels in sarcopenia mice. Treatment with GQZJD also decreased the mitochondrial reactive oxygen species level and serum lipid peroxide Malonaldehyde concentration. and increased the mitochondrial membrane potential, adenosine triphosphate level, 8­hydroxy-2-deoxyguanosine content, mitochondrial DNA copy number, and the mitochondrial fission factor dynamin-related protein 1. Non-targeted metabolomics suggested that the sarcopenia therapeutic effect of GQZJD on sarcopenia may occur through the glycerophospholipid metabolism, choline metabolism in cancer, phenylalanine metabolism and tyrosine metabolism pathways, implying an association with AMP-activated protein kinase (AMPK) and related signals. Further, the molecular docking results hinted that AMPK performed well in terms of binding energy with the 27 IAIBs of GQZJD (average binding energy, -7.5 kcal/mol). Finally, we determined that GQZJD significantly activated the key targets of the AMPK/peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α)/nuclear factor erythroid 2-related factor 2 (Nrf2) axis.. CONCLUSIONS: Our results demonstrated that GQZJD ameliorated d-galactose-induced sarcopenia by promoting the animal behaviours, facilitating mitochondrial function and restoring mitochondrial energy metabolism. with its effects mediated by the AMPK/PGC-1α/Nrf2 axis. Over all, GQZJD represents a promising therapeutic candidate that ameliorated sarcopenia in aging mice.

Effects of dietary compounds on nuclear factor erythroid 2-related factor 2 (Nrf2) modulation in chronic kidney disease: a systematic review of clinical trials.

Nuclear factor-erythroid 2-related factor 2 (Nrf2) is an important transcription factor that activates antioxidant genes and increases detoxifying enzymes. Studies have shown that dietary compounds can activate the Nrf2 expression and improve the antioxidant response in patients with exacerbated oxidative stress, such as chronic kidney disease (CKD). We aimed to evaluate the efficacy of nutritional interventions on Nrf2 expression and phase II antioxidant enzymes in clinical trials in CKD. We searched PubMed, Lilacs, Embase, Scopus, and Cochrane Library databases of published clinical trials and the Cochrane tool was used for the quality assessment of the studies included. We reported this review according to the PRISMA and it was registered in PROSPERO (42023389619). Thirty-nine studies were included in this review; nine evaluated the Nrf2 expression and three showed an increase in its expression. Twenty-three studies found an increase in the antioxidant enzyme levels, including superoxide dismutase, catalase, and glutathione peroxidase. Moreover, a high risk of bias was found in most of the studies and high heterogeneity in the designs, type, and duration of supplementation administered. These results suggest that dietary supplementations have a promising effect on the antioxidant enzyme response, however, it is recommended that further studies should be carried out.

The Potential Association Between microRNA 135-5P and p62 and Their Effect on NRF2 Pathway in Multiple Sclerosis.

Background: Multiple Sclerosis (MS) is a prevalent non-traumatic disabling disease affecting young adults, characterized by complexity in its pathogenesis. Nuclear factor erythroid 2-Related Factor 2 (NRF2) serves as a crucial transcriptional regulator of anti-inflammatory and antioxidant enzymes, influenced by the ubiquitous protein p62. It acts as a scaffold directing substrates to autophagosomes. This study aims to explore the potential association between microRNA 135-5p and p62 and their impact on inflammation and oxidative stress through the NRF2 pathway in MS. Methods: The study included 30 healthy controls and 60 MS patients (relapsing-remitting and secondary progressive). Real-time PCR was employed for the detection of Nrf2, p62, miRNA135-5P, and NF-κB in serum, while p53 levels were determined using ELISA. Results: Nrf2 and p62 expression was significantly downregulated in the MS group compared to controls. Conversely, miRNA135-5P, NF-κB expression, and P53 levels were significantly elevated in the MS group. Conclusions: This study reveals a potential association between miRNA 135-5p and p62, indicating their role in the pathogenesis of MS. Results suggest that miRNA 135-5p and p62 may influence inflammation and oxidative stress in MS through the NRF2 pathway, potentially mediated by NF-κB and p53.

Transcriptomics pave the way into mechanisms of cobalt and nickel toxicity: Nrf2-mediated cellular responses in liver carcinoma cells.

Cobalt (Co) and Nickel (Ni) are used nowadays in various industrial applications like lithium-ion batteries, raising concerns about their environmental release and public health threats. Both metals are potentially carcinogenic and may cause neurological and cardiovascular dysfunctions, though underlying toxicity mechanisms have to be further elucidated. This study employs untargeted transcriptomics to analyze downstream cellular effects of individual and combined Co and Ni toxicity in human liver carcinoma cells (HepG2). The results reveal a synergistic effect of Co and Ni, leading to significantly higher number of differentially expressed genes (DEGs) compared to individual exposure. There was a clear enrichment of Nrf2 regulated genes linked to pathways such as glycolysis, iron and glutathione metabolism, and sphingolipid metabolism, confirmed by targeted analysis. Co and Ni exposure alone and combined caused nuclear Nrf2 translocation, while only combined exposure significantly affects iron and glutathione metabolism, evidenced by upregulation of HMOX-1 and iron storage protein FTL. Both metals impact sphingolipid metabolism, increasing dihydroceramide levels and decreasing ceramides, sphingosine and lactosylceramides, along with diacylglycerol accumulation. By combining transcriptomics and analytical methods, this study provides valuable insights into molecular mechanisms of Co and Ni toxicity, paving the way for further understanding of metal stress.

Aristolochic acids-hijacked p53 promotes liver cancer cell growth by inhibiting ferroptosis.

Aristolochic acids (AAs) have been identified as a significant risk factor for hepatocellular carcinoma (HCC). Ferroptosis is a type of regulated cell death involved in the tumor development. In this study, we investigated the molecular mechanisms by which AAs enhanced the growth of HCC. By conducting bioinformatics and RNA-Seq analyses, we found that AAs were closely correlated with ferroptosis. The physical interaction between p53 and AAs in HepG2 cells was validated by bioinformatics analysis and SPR assays with the binding pocket sites containing Pro92, Arg174, Asp207, Phe212, and His214 of p53. Based on the binding pocket that interacts with AAs, we designed a mutant and performed RNA-Seq profiling. Interestingly, we found that the binding pocket was responsible for ferroptosis, GADD45A, NRF2, and SLC7A11. Functionally, the interaction disturbed the binding of p53 to the promoter of GADD45A or NRF2, attenuating the role of p53 in enhancing GADD45A and suppressing NRF2; the mutant did not exhibit the same effects. Consequently, this event down-regulated GADD45A and up-regulated NRF2, ultimately inhibiting ferroptosis, suggesting that AAs hijacked p53 to down-regulate GADD45A and up-regulate NRF2 in HepG2 cells. Thus, AAs treatment resulted in the inhibition of ferroptosis via the p53/GADD45A/NRF2/SLC7A11 axis, which led to the enhancement of tumor growth. In conclusion, AAs-hijacked p53 restrains ferroptosis through the GADD45A/NRF2/SLC7A11 axis to enhance tumor growth. Our findings provide an underlying mechanism by which AAs enhance HCC and new insights into p53 in liver cancer. Therapeutically, the oncogene NRF2 is a promising target for liver cancer.

Momordica charantia L.-derived exosome-like nanovesicles stabilize p62 expression to ameliorate doxorubicin cardiotoxicity.

BACKGROUND: Doxorubicin (DOX) is a first-line chemotherapeutic drug for various malignancies that causes cardiotoxicity. Plant-derived exosome-like nanovesicles (P-ELNs) are growing as novel therapeutic agents. Here, we investigated the protective effects in DOX cardiotoxicity of ELNs from Momordica charantia L. (MC-ELNs), a medicinal plant with antioxidant activity. RESULTS: We isolated MC-ELNs using ultracentrifugation and characterized them with canonical mammalian extracellular vesicles features. In vivo studies proved that MC-ELNs ameliorated DOX cardiotoxicity with enhanced cardiac function and myocardial structure. In vitro assays revealed that MC-ELNs promoted cell survival, diminished reactive oxygen species, and protected mitochondrial integrity in DOX-treated H9c2 cells. We found that DOX treatment decreased the protein level of p62 through ubiquitin-dependent degradation pathway in H9c2 and NRVM cells. However, MC-ELNs suppressed DOX-induced p62 ubiquitination degradation, and the recovered p62 bound with Keap1 promoting Nrf2 nuclear translocation and the expressions of downstream gene HO-1. Furthermore, both the knockdown of Nrf2 and the inhibition of p62-Keap1 interaction abrogated the cardioprotective effect of MC-ELNs. CONCLUSIONS: Our findings demonstrated the therapeutic beneficials of MC-ELNs via increasing p62 protein stability, shedding light on preventive approaches for DOX cardiotoxicity.