Nuclear Factor E2-related Factor-2 Research Articles

The protective roles of eugenol on type 1 diabetes mellitus through NRF2-mediated oxidative stress pathway.

Type 1 diabetes mellitus (T1DM), known as insulin-dependent diabetes mellitus, is characterized by persistent hyperglycemia resulting from damage to the pancreatic β cells and an absolute deficiency of insulin, leading to multi-organ involvement and a poor prognosis. The progression of T1DM is significantly influenced by oxidative stress and apoptosis. The natural compound eugenol (EUG) possesses anti-inflammatory, anti-oxidant, and anti-apoptotic properties. However, the potential effects of EUG on T1DM had not been investigated. In this study, we established the streptozotocin (STZ)-induced T1DM mouse model in vivo and STZ-induced pancreatic β cell MIN6 cell model in vitro to investigate the protective effects of EUG on T1DM, and tried to elucidate its potential mechanism. Our findings demonstrated that the intervention of EUG could effectively induce the activation of nuclear factor E2-related factor 2 (NRF2), leading to an up-regulation in the expressions of downstream proteins NQO1 and HMOX1, which are regulated by NRF2. Moreover, this intervention exhibited a significant amelioration in pancreatic β cell damage associated with T1DM, accompanied by an elevation in insulin secretion and a reduction in the expression levels of apoptosis and oxidative stress-related markers. Furthermore, ML385, an NRF2 inhibitor, reversed these effects of EUG. The present study suggested that EUG exerted protective effects on pancreatic β cells in T1DM by attenuating apoptosis and oxidative stress through the activation of the NRF2 signaling pathway. Consequently, EUG holds great promise as a potential therapeutic candidate for T1DM.

NRF2 Antioxidant Response and Interferon-Stimulated Genes Are Differentially Expressed in SARS-CoV-2-Positive Young Subjects.

Several respiratory viruses, including Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2), suppress nuclear factor-E2-related factor-2 (NRF2) antioxidant response, generating oxidative stress conditions to its advantage. NRF2 has also been reported to regulate the innate immune response through the inhibition of the interferon (IFN) pathway. However, its modulation in younger individuals and its correlation with the IFN response remain to be elucidated. The NRF2 and redox-related genes expression was examined in nasopharyngeal swabs from children attending the pediatric hospital for SARS-CoV-2 molecular testing. Expression levels were analyzed by stratifying the population according to the SARS-CoV-2 positivity, age, or the presence of symptoms. The results were correlated with Types I and III IFN genes and IFN-stimulated genes (ISGs). We found that NRF2 expression was markedly diminished in positive patients compared to negative. Moreover, it correlated with higher expression of IFNα2 and IFNλ3, as well as ISG15 and ISG56. Interestingly, symptomatic patients with anosmia/ageusia showed pronounced expression of apurinic/apyrimidinic endonuclease1/redox factor 1 (APE1), together with Type I IFNs, ISG56, and the inflammasome component NLRP3. The results indicate an interdependence between NRF2 antioxidant pathway and IFN-mediated response during SARS-CoV-2 infection in young subjects.

Quercetin Regulates the Polarization of Microglia through the NRF2/HO1 Pathway and Mitigates Alzheimer's Disease.

Alzheimer's disease (AD) is a burdening disease and is the main cause of dementia. Quercetin (Que), an antioxidant, plays potential roles in treating age-related disorders, including AD. This study aimed to validate the effects of Que on AD and explore the underlying mechanisms. Mice with no treatment, amyloid-β Aβ (1-42) treatment (for acquiring AD model), or Aβ (1-42) plus Que treatment were used. Cognitive function was determined using the open field test (OFT), objective recognition test, and Y-maze test. In brain tissues, mRNA levels of inflammation cytokines, the M1 microglia marker cluster of differentiation (CD)86, and the M2 microglia markers arginase 1 (Arg1) and CD206 were measured. Nuclear factor E2-related factor 2 (NRF2)/heme oxygenase-1 (HO1) pathway-related proteins were detected by western blot. Additionally, mechanisms were investigated using human microglia HMC3 cells treated with Aβ (1-42) and Aβ (1-42) plus Que. The NRF2/HO1 pathway in HMC3 cells was inhibited using the selective inhibitor ML385. Cell viability and death were assessed using the cell counting kit-8 (CCK-8) and lactate dehydrogenase (LDH) release levels, respectively. Cell apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). Levels of NRF2/HO1 pathway-related proteins, inflammation cytokines, and oxidative stress-related markers, including malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (reduced glutathione (GSH)/oxidized glutathione disulfide (GSSG)), were determined in HMC3 cells. Flow cytometry was used to determine M1 markers CD86 and CD80 and M2 markers CD206 and CD163. Cognitive ability was impaired in AD model mice, and Que treatment reversed this impairment (p < 0.05). Levels of interleukin (IL)-1β, tumor necrosis factor-alpha (TNF-α), and IL-6 were increased, while M2 markers were decreased in the AD model mouse brain. Que treatment reversed these changes (p < 0.001). The NRF2/HO1 pathway was slightly inhibited in AD mice brain, while further activated by Que (p < 0.05). Que reversed the Aβ (1-42)-impaired cell viability. Through greatly activating NRF2/HO1 pathway, Que suppressed Aβ (1-42)-induced cell death, decreased Aβ (1-42)-promoted IL-1β, TNF-α, IL-6, MDA, CD86 and CD80, increased Aβ (1-42)-suppressed SOD and GSH/GSSG, and greatly increased CD206 and CD163 (p < 0.01). Quercetin, through the activation of the NRF2/HO1 pathway, promotes M2 polarization of microglia, suppresses Aβ (1-42)-induced inflammation and oxidative stress, protects microglia from Aβ (1-42)-induced damage, improves cognitive function in mice, and demonstrates therapeutic potential for AD.

Ultrasonic-assisted extraction and the antioxidative mechanism of eggplant root polysaccharide

Ultrasonic-assisted extraction and the antioxidative mechanism of eggplant root polysaccharide

Cadmium and polyvinyl chloride microplastics induce mitochondrial damage and apoptosis under oxidative stress in duck kidney

Polyvinyl chloride microplastics (PVC-MPs) and Cadmium (Cd) are widely occurring water pollutants that interact with each other to exert toxic effects. As a waterfowl, Muscovy duck is more susceptible to PVC-MPs and Cd than land poultry. In this study, Muscovy duck was used as a research model, and 10 mg/L PVC-MPs and 50 mg/kg Cd were used alone and in combine to explore the effect on the kidney of Muscovy duck. We found that treatment of Cd or PVC-MPs alone changed the kidney weight, increased creatinine and urea nitrogen content, and disrupted oxidative balance and macro/trace element metabolism, while the combination of PVC-MPs+Cd reduced the accumulation of Cd in the kidney. In addition, treatment of Cd and PVC-MPs alone caused mitochondrial damage, increase or decrease of mitochondria-associated proteins (Fis1, Drp1, PGC-1α, Nrf1), and Nrf2 signaling pathway plays a key role in detoxification and alleviation of oxidative stress, and we found that PVC-MPs+Cd treatment recovered related proteins (Nrf2, Keap-1, HO-1, NQO1, AC-SOD2, SOD2) compared with the Cd and PVC-MPs alone treatment. Finally, we detected changes in apoptosis-related proteins and genes (Caspase-3, Caspase-9, Bax, Bcl-2, Cytc) and TUNEL staining, and after PVC-MPs+Cd treatment, apoptosis-related proteins/genes recovered and the apoptosis rate decreased compared with the Cd and PVC-MPs alone treatment. These results indicate that renal function is impaired, oxidative stress and trace element metabolism disorder, nuclear factor-E2 related factor 2 (Nrf2) is activated into the nucleus to induce the expression of related antioxidant proteins (such as HO-1, NQO1). These injuries can induce mitochondrial damage and eventually lead to renal cell apoptosis. To sum up, these evidence show that Cd or PVC-MPs can induce kidney oxidative damage, trace element metabolism disorder, mitochondrial damage and apoptosis.

Site-specific drug release of monomethyl fumarate to treat oxidative stress disorders.

Treatment of diseases of oxidative stress through activation of the antioxidant nuclear factor E2-related factor 2 (NRF2) is limited by systemic side effects. We chemically functionalize the NRF2 activator monomethyl fumarate to require Baeyer-Villiger oxidation for release of the active drug at sites of oxidative stress. This prodrug reverses chronic pain in mice with reduced side effects and could be applied to other disorders of oxidative stress.

A novel effect of sulforaphane on promoting mouse granulosa cells proliferation via the NRF2–TKT pathway

Granulosa cells (GCs) is essential for maintaining follicular development. Follicle-stimulating Hormone (FSH) has been demonstrated to effectively promote GCs proliferation, driving the establishment of various superovulation techniques for animal husbandry. However, these techniques face challenges, such as high costs, hormonal imbalances, and an increased risk of early ovarian dysfunction. Therefore, it is important to investigate new methods to improve GCs proliferation. This study aimed to investigate the effect of sulforaphane (SFN) on ovarian GCs proliferation and the underlying mechanisms. A comparative transcriptomic analysis of ovaries from the control, SFN, and FSH groups was conducted to identify the primary factors contributing to high proliferative capacity. The role of SFN in the regulation of cell proliferation has been examined in mouse ovarian GCs. Gene interference, overexpression, CUT&TAG technology, and transcriptome analyses were performed to elucidate the underlying mechanisms of the nuclear factor E2-related factor 2 (NRF2)-transketolase (TKT) axis in mediating GCs proliferation. Our research revealed a previously unknown function of SFN, an isothiocyanate of plant origin that is prevalent in cruciferous vegetables, in facilitating the proliferation of mouse ovarian GCs. The efficacy of SFN in enhancing GCs proliferation is similar to that of FSH. At the mechanistic level, SFN promotes NRF2 to transport to the nucleus, which subsequently activates the key enzyme of the non-oxidative pentose phosphate pathway TKT. This activation is instrumental in generating ribose 5-phosphate, a critical precursor for amino acid and nucleotide biosynthesis that underpins the proliferation of GCs. Collectively, our findings delineate a novel pathway by which SFN, through the NRF2-TKT axis, enhances the nucleotide pool and thereby supports the proliferation of mouse GCs, presenting novel avenues for exploration in reproductive biology and agricultural sciences.

Single-cell RNA sequencing reveals that NRF2 regulates vascular smooth muscle cell phenotypic switching in abdominal aortic aneurysm.

Abdominal aortic aneurysm (AAA) is a life-threatening disease characterized by extensive membrane destruction in the vascular wall that is closely associated with vascular smooth muscle cell (VSMC) phenotypic switching. A thorough understanding of the changes in regulatory factors during VSMC phenotypic switching is essential for managing AAA therapy. In this study, we revealed the impact of NRF2 on the modulation of VSMC phenotype and the development of AAA based on single-cell RNA sequencing analysis. By utilizing a murine model of VSMC-specific knockout of nuclear factor E2-related factor 2 (NRF2), we observed that the absence of NRF2 in VSMCs exacerbated AAA formation in an angiotensin II-induced AAA model. The downregulation of NRF2 promoted VSMC phenotypic switching, leading to an enhanced inflammatory response. Through genome-wide transcriptome analysis and loss- or gain-of-function experiments, we discovered that NRF2 upregulated the expression of VSMC contractile phenotype-specific genes by facilitating microRNA-145 (miR-145) expression. Our data identified NRF2 as a novel regulator involved in maintaining the VSMC contractile phenotype while also influencing AAA formation through an miR-145-dependent regulatory mechanism.

Protective effect and mechanism of Lycium ruthenicum Murray anthocyanins against retinal damage induced by blue light exposure.

Lycium ruthenicum Murray (LR) is a medicine and edible plant in Northwest China, and L. ruthenicum Murray anthocyanins (LRA) are green antioxidants with various pharmacological activities, such as antioxidant and anti-inflammatory activities. However, the protective effect and mechanism of LRA against retinal damage induced by blue light exposure are poorly understood. This study explored the protective effects and potential mechanisms of LRA on retinal damage induced by blue light exposure invitro and invivo. The results showed that LRA could ameliorate oxidative stress injury by activating the antioxidant stress nuclear factor-related factor 2 pathway, promoting the expression of phase II detoxification enzymes (HO-1, NQO1) and endogenous antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase), and reducing reactive oxygen species and malondialdehyde levels. Additionally, LRA could inhibit inflammatory response by decreasing the expression of blue light exposure-induced nuclear factor-κB (NF-κB) pathway-related proteins (NF-κB and p-IκBα), as well as interleukin (IL)-6, tumor necrosis factor-α, IL-1β pro-inflammatory factors and pro-inflammatory chemokine VEGF, and increasing the expression of anti-inflammatory factor IL-10. Furthermore, LRA could ameliorate oxidative stress-induced apoptosis by upregulating Bcl-2 and downregulating Bax and Caspase-3 protein expression. All these results indicate that LRA can be used as an antioxidant dietary supplement for the treatment or prevention of retinal diseases.

Regulation of YAP translocation by myeloid Pten deficiency alleviates acute lung injury via inhibition of oxidative stress and inflammation

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is intricately involved in modulating the inflammatory response in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Nevertheless, the myeloid PTEN governing Hippo-YAP pathway mediated oxidative stress and inflammation in lipopolysaccharide (LPS)-induced ALI remains to be elucidate. The floxed Pten (PtenFL/FL) and myeloid-specific Pten knockout (PtenM-KO) mice were intratracheal instill LPS (5mg/kg) to establish ALI, then Yap siRNA mix with the mannose-conjugated polymers was used to knockdown endogenous macrophage YAP in some PtenM-KO mice before LPS challenged. The bone marrow-derived macrophages (BMMs) from PtenFL/FL and PtenM-KO mice were obtained, and BMMs were transfected with CRISPR/Cas9-mediated glycogen synthase kinase 3 Beta (GSK3β) knockout (KO) or Yes-associated protein (YAP) KO vector subjected to LPS (100ng/ml) challenged or then cocultured with MLE12cells. Here, our findings demonstrate that myeloid-specific PTEN deficiency exerts a protective against LPS-induced oxidative stress and inflammation dysregulated in ALI model. Moreover, ablation of the PTEN-YAP axis in macrophages results in reduced nuclear factor-E2-related factor-2 (NRF2) expression, a decrease in antioxidant gene expression, augmented levels of free radicals, lipid and protein peroxidation, heightened generation of pro-inflammatory cytokines, ultimately leading to increased apoptosis in MLE12cells. Mechanistically, it is noteworthy that the deletion of myeloid PTEN promotes YAP translocation and regulates NRF2 expression, alleviating LPS-induced ALI via the inhibition of GSK3β and MST1 binding. Our study underscores the crucial role of the myeloid PTEN-YAP-NRF2 axis in governing oxidative stress and inflammation dysregulated in ALI, indicating its potential as a therapeutic target for ALI.

Paeoniflorin regulates RhoA/ROCK1 and Nrf2 pathways in PDLIM1-dependent or independent manners in oxidative stressed melanocytes.

The adhesive properties of vitiligo melanocytes have decreased under oxidative stress., cytoskeleton proteins can control cell adhesion. Paeoniflorin (PF) was proved to resist hydrogen peroxide (H2O2)-induced oxidative stress in melanocytes via nuclear factorE2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. This study was to investigate whether PF exerts anti-oxidative effect through influencing cytoskeleton markers or potential signaling pathway. Human Oxidative Stress Plus array was used to identify the differentially expressed genes between H2O2 + PF group and H2O2 only group, in PIG1 and PIG3V melanocyte cell lines respectively. Western blotting was used to verify the PCR array results and to test the protein expression levels of cytoskeleton markers including Ras homolog family member A (RhoA), Rho-associated kinase 1 (ROCK1) and antioxidative marker Nrf2. Small interfering RNA was used to knock down PDZ and LIM domain 1 (PDLIM1). PF increased the expressions of PDLIM1, RhoA and ROCK1 in H2O2-induced PIG1, in contrast, decreased the expressions of PDLIM1 and ROCK1 in H2O2-induced PIG3V. Knockdown of PDLIM1 increased the expressions of RhoA and Nrf2 in PF-pretreated H2O2-induced PIG1, and ROCK1 and Nrf2 in PF-pretreated H2O2-induced PIG3V. PF regulates RhoA/ROCK1 and Nrf2 pathways in PDLIM1-dependent or independent manners in H2O2-induced melanocytes. In PIG1, PF promotes PDLIM1 to inhibit RhoA/ROCK1 pathway or activates Nrf2/HO-1 pathway, separately. In PIG3V, PF directly downregulates ROCK1 in PDLIM1-independent manner or upregulates Nrf2 dependent of PDLIM1.

Interaction between RNF4 and SART3 is associated with the risk of schizophrenia

Interaction between RNF4 and SART3 is associated with the risk of schizophrenia

Melatonin suppresses atherosclerosis by ferroptosis inhibition via activating NRF2 pathway.

Melatonin (MLT), a conserved small indole compound, exhibits anti-inflammatory and antioxidant properties, contributing to its cardioprotective effects. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is associated with atherosclerosis disease risk, and is known as an atherosclerosis risk biomarker. This study aimed to investigate the impact of MLT on Lp-PLA2 expression in the atherosclerotic process and explore the underlying mechanisms involved. Invivo, ApoE-/- mice were fed a high-fat diet, with or without MLT administration, after which the plaque area and collagen content were assessed. Macrophages were pretreated with MLT combined with ox-LDL, and the levels of ferroptosis-related proteins, NRF2 activation, mitochondrial function, and oxidative stress were measured. MLT administration significantly attenuated atherosclerotic plaque progression, as evidenced by decreased plaque area and increased collagen. Compared with those in the high-fat diet (HD) group, the levels of glutathione peroxidase 4 (GPX4) and SLC7A11 (xCT, a cystine/glutamate transporter) in atherosclerotic root macrophages were significantly increased in the MLT group. Invitro, MLT activated the nuclear factor-E2-related Factor 2 (NRF2)/SLC7A11/GPX4 signaling pathway, enhancing antioxidant capacity while reducing lipid peroxidation and suppressing Lp-PLA2 expression in macrophages. Moreover, MLT reversed ox-LDL-induced ferroptosis, through the use of ferrostatin-1 (a ferroptosis inhibitor) and/or erastin (a ferroptosis activator). Furthermore, the protective effects of MLT on Lp-PLA2 expression, antioxidant capacity, lipid peroxidation, and ferroptosis were decreased in ML385 (a specific NRF2 inhibitor)-treated macrophages and in AAV-sh-NRF2 treated ApoE-/- mice. MLT suppresses Lp-PLA2 expression and atherosclerosis processes by inhibiting macrophage ferroptosis and partially activating the NRF2 pathway.

Uncovering the Cardioprotective Potential of Diacerein in Doxorubicin Cardiotoxicity: Mitigating Ferritinophagy-Mediated Ferroptosis via Upregulating NRF2/SLC7A11/GPX4 Axis.

Doxorubicin (DOX)-induced cardiotoxicity (DIC) is a life-threatening clinical issue with limited preventive approaches, posing a substantial challenge to cancer survivors. The anthraquinone diacerein (DCN) exhibits significant anti-inflammatory, anti-proliferative, and antioxidant actions. Its beneficial effects on DIC have yet to be clarified. Therefore, this study investigated DCN's cardioprotective potency and its conceivable molecular targets against DIC. Twenty-eight Wister rats were assigned to CON, DOX, DCN-L/DOX, and DCN-H/DOX groups. Serum cardiac damage indices, iron assay, oxidative stress, inflammation, endoplasmic reticulum (ER) stress, apoptosis, ferritinophagy, and ferroptosis-related biomarkers were estimated. Nuclear factor E2-related factor 2 (NRF2) DNA-binding activity and phospho-p53 immunoreactivity were assessed. DCN administration effectively ameliorated DOX-induced cardiac cytomorphological abnormalities. Additionally, DCN profoundly combated the DOX-induced labile iron pool expansion alongside its consequent lethal lipid peroxide overproduction, whereas it counteracted ferritinophagy and enhanced iron storage. Indeed, DCN valuably reinforced the cardiomyocytes' resistance to ferroptosis, mainly by restoring the NRF2/solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) signaling axis. Furthermore, DCN abrogated the cardiac oxidative damage, inflammatory response, ER stress, and cardiomyocyte apoptosis elicited by DOX. In conclusion, for the first time, our findings validated DCN's cardioprotective potency against DIC based on its antioxidant, anti-inflammatory, anti-ferroptotic, and anti-apoptotic imprint, chiefly mediated by the NRF2/SLC7A11/GPX4 axis. Accordingly, DCN could represent a promising therapeutic avenue for patients under DOX-dependent chemotherapy.

Modifying Effects of Genetic Variations on the Association Between Dietary Isothiocyanate Exposure and Non-muscle Invasive Bladder Cancer Prognosis in the Be-Well Study.

Dietary isothiocyanate (ITC) exposure from cruciferous vegetable (CV) intake may improve non-muscle invasive bladder cancer (NMIBC) prognosis. This study aims to investigate whether genetic variations in key ITC-metabolizing/functioning genes modify the associations between dietary ITC exposure and NMIBC prognosis outcomes. In the Bladder Cancer Epidemiology, Wellness, and Lifestyle Study (Be-Well Study), a prospective cohort of 1472 incident NMIBC patients, dietary ITC exposure is assessed by self-reported CV intake and measured in plasma ITC-albumin adducts. Using Cox proportional hazards regression models, stratified by single nucleotide polymorphisms (SNPs) in nine key ITC-metabolizing/functioning genes, it is calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for recurrence and progression. The rs15561 in N-acetyltransferase 1 (NAT1) is alter the association between CV intake and progression risk. Multiple SNPs in nuclear factor E2-related factor 2 (NRF2) and nuclear factor kappa B (NFκB) are modify the associations between plasma ITC-albumin adduct level and progression risk (pint < 0.05). No significant association is observed with recurrence risk. Overall, >80% study participants are present with at least one protective genotype per gene, showing an average 65% reduction in progression risk with high dietary ITC exposure. Despite that genetic variations in ITC-metabolizing/functioning genes may modify the effect of dietary ITCs on NMIBC prognosis, dietary recommendation of CV consumption may help improve NMIBC survivorship.

Tempol alleviates acute lung injury by affecting glutathione synthesis through Nrf2 and inhibiting ferroptosis in lung epithelial cells.

As a life-threatening disease, acute lung injury (ALI) may progress to chronic pulmonary fibrosis. For the treatment of lung injury, Tempol is a superoxide dismutase mimetic and intracellular redox agent that can be a potential drug. This study investigated the regulatory mechanism of Tempol in the treatment of ALI. A mouse model of ALI was established, and HE staining was used to examine histomorphology. The CCK-8 assay was used to measure cell viability, and oxidative stress was assessed by corresponding kits. Flow cytometry and dichlorodihydrofluorescein diacetatestaining assays were used to detect reactive oxygen species (ROS)levels. Protein expression levels were measured by Western blot analysis and ELISA. Pulmonary vascular permeability was used to measure the lung wet/dry weight ratio. The level of oxidative stress was increased in ALI mice, and the level of ferroptosis was upregulated. Tempol inhibited this effect and alleviated ALI. The administration of Tempol alleviated the pathological changes in ALI, inhibited pulmonary vascular permeability, and improved lung injury in ALI mice. The upregulation of genes essential for glutathione (GSH) metabolism induced by lipopolysaccharide(LPS) was inhibited by Tempol. In addition,nuclear factor-related factor 2 (Nrf2)is activated by Tempol therapy to regulate the de novo synthesis pathway of GSH, thereby alleviating LPS-induced lung epithelial cell damage. The results showed that Tempol alleviated ALI by activating the Nrf2 pathway to inhibit oxidative stress and ferroptosis in lung epithelial cells. In conclusion, this study demonstrates that Tempol alleviates ALI by inhibiting ferroptosis in lung epithelial cells through the effect of Nrf2 on GSH synthesis.

A DNA tetrahedron-based ferroptosis-suppressing nanoparticle: superior delivery of curcumin and alleviation of diabetic osteoporosis

Diabetic osteoporosis (DOP) is a significant complication that poses continuous threat to the bone health of patients with diabetes; however, currently, there are no effective treatment strategies. In patients with diabetes, the increased levels of ferroptosis affect the osteogenic commitment and differentiation of bone mesenchymal stem cells (BMSCs), leading to significant skeletal changes. To address this issue, we aimed to target ferroptosis and propose a novel therapeutic approach for the treatment of DOP. We synthesized ferroptosis-suppressing nanoparticles, which could deliver curcumin, a natural compound, to the bone marrow using tetrahedral framework nucleic acid (tFNA). This delivery system demonstrated excellent curcumin bioavailability and stability, as well as synergistic properties with tFNA. Both in vitro and in vivo experiments revealed that nanoparticles could enhance mitochondrial function by activating the nuclear factor E2-related factor 2 (NRF2)/glutathione peroxidase 4 (GPX4) pathway, inhibiting ferroptosis, promoting the osteogenic differentiation of BMSCs in the diabetic microenvironment, reducing trabecular loss, and increasing bone formation. These findings suggest that curcumin-containing DNA tetrahedron-based ferroptosis-suppressing nanoparticles have a promising potential for the treatment of DOP and other ferroptosis-related diseases.

Mitochondria-derived methylmalonic acid aggravates ischemia–reperfusion injury by activating reactive oxygen species-dependent ferroptosis

Ferroptosis is a regulatory cell death process pivotal in myocardial ischemia–reperfusion (I/R) injury. However, the precise mechanism underlying myocardial ferroptosis remains less known. In this study, we investigated the pathophysiological mechanisms of methylmalonic acid (MMA) associated with ferroptosis activation in cardiomyocytes after I/R. We found an increase level of MMA in patients with acute myocardial injury after reperfusion and AC16 cells under hypoxia/reoxygenation (H/R) condition. MMA treatment was found to be associated with excessive oxidative stress in cardiomyocytes, leading to ferroptosis-related myocardial injury. In mice with I/R injury, MMA treatment aggravated myocardial oxidative stress and ferroptosis, which amplified the myocardial infarct size and cardiac dysfunction. Mechanistically, MMA promoted NOX2/4 expression to increase reactive oxygen species (ROS) production in cardiomyocytes, aggravating myocardial injury. Notably, the increased ROS further activated ferroptosis by inhibiting solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) expression. In addition, MMA decreased the ectopic nuclear distribution of nuclear factor E2-related factor 2 (NRF2) by increasing the interaction between NRF2 and kelch-like ECH-associated protein 1 (KEAP1). This impeded the activation of GPX4/SLC7A11, downstream of NRF2, activating ferroptosis and aggravating myocardial cell injury. Collectively, our study indicates that MMA activates oxidative stress and ROS generation, which induces ferroptosis to exacerbate cardiomyocyte injury in an I/R model. These findings may provide a new perspective for the clinical treatment of I/R injury and warrant further investigation.

4-Octyl Itaconate Inhibits Proinflammatory Cytokine Production in Behcet's Uveitis and Experimental Autoimmune Uveitis.

4-octyl itaconate (4-OI) is an anti-inflammatory metabolite that activates the nuclear-factor-E2-related factor 2 (NRF2) signaling. In the current work, we investigated whether 4-OI could affect the production of proinflammatory cytokines in Behcet's uveitis (BU) and experimental autoimmune uveitis (EAU). Peripheral blood mononuclear cells (PBMCs) of active BU patients and healthy individuals with in vitro 4-OI treatment were performed to assess the influence of 4-OI on the proinflammatory cytokine production. EAU was induced and used for investigating the influence of 4-OI on the proinflammatory cytokine production in vivo. The flow cytometry, qPCR, and ELISA were performed to detect proinflammatory cytokine expression. NRF2 signaling activation was evaluated by qPCR and western blotting (WB). Splenic lymphocyte transcriptome was performed by RNA sequencing. The NRF2 expression by BU patients-derived PBMCs was lower than that by healthy individuals. After treatment with 4-OI, the proportion of Th17 cells, along with the expression of proinflammatory cytokines (IL-17, TNF-α, MCP-1, and IL-6) by PBMCs, were downregulated, and anti-inflammatory cytokine (IL-10) expression was upregulated, although IFN-γ expression was unaffected. The EAU severity was ameliorated by 4-OI in association with a lower splenic Th1/Th17 cell proportion and increased nuclear NRF2 expression. Additionally, 4-OI downregulated a set of 248 genes, which were enriched in pathways of positive regulation of immune responses. The present study shows an inhibitory effect of 4-OI on the proinflammatory cytokine production in active BU patients and EAU mice, possibly mediated through activating NRF2 signaling. These findings suggest that 4-OI could act as a potential therapeutic drug for the treatment and prevention of BU in the future study.

SIRT1-NRF2-TFEB axis-mediated hepatic lipophagy alleviates the lipid deposition induced by high glucose in yellow catfish Pelteobagrus fulvidraco.

Metabolic stress induces lipophagy, a crucial process in lipid catabolism, which is under the regulation of autophagy involving transcription factor EB (TFEB). However, the precise mechanisms underlying TFEB's control remain enigmatic. In this study, we focused on yellow catfish (Pelteobagrus fulvidraco) as the model to investigate lipophagy activation under high glucose-induced lipid deposition. We hypothesized that lipophagy mediates high glucose-induced lipid deposition and proposed the involvement of the SIRT1-NRF2-TFEB pathway in the activation of lipophagy. We found that there was a functional antioxidative responsive element (ARE) on the tfeb gene promoter; high glucose (HG) increased the nuclear translocation of nuclear factor E2-related factor 2 (NRF2) recruitment to the tfeb promoter; TFEB, whose expression is regulated by NRF2, mediated the HG-induced activation of lipophagy and lipolysis. Moreover, we found that HG increased the silencing information regulator 2 related enzymes 1 (SIRT1) expression, and that the SIRT1 mediates NRF2 translocation to the nucleus, increased TFEB expression and activated autophagy. In the glucose tolerance test, blood glucose increased rapidly and plateaued at 4-h glucose after injection and then declined until 48-h post-injection. Generally speaking, the transcript level and protein expression of SIRT1, NRF2, TFEB, microtubule-associated proteins 1A/1B light chain 3B (LC3B), and autophagy-related 6 (Beclin1) showed similar trend after glucose injection, and trends to increase and plateau at 4-h injection, then decline until 16-h post-injection, and finally increased until 48-h post-injection. These results indicated that the SIRT1-NRF2-TFEB axis-mediated lipophagy may be an adaptive response to glucose injection. Collectively, for the first time, we found that NRF2 was associated directly with TFEB-mediated transcriptional control of hepatic lipophagy, and that lipophagy helps to alleviate the HG-induced lipid deposition via SIRT1-NRF2-TFEB activation in yellow catfish.