Dual Deletion of Keap1 and Rbpjκ Genes in Liver Leads to Hepatomegaly and Hypercholesterolemia.

The hepatic deletion of Rbpjκ (RbpjF/F::AlbCre) in the mouse leads to exhibition of the Alagille syndrome phenotype during early postnatal liver development with hyperlipidemia and cholestasis due to attenuated disruption of NOTCH signaling. Given the roles of NRF2 signaling in the regulation of lipid metabolism and bile ductal formation, it was anticipated that these symptoms could be alleviated by enhancing NRF2 signaling in the RbpjF/F::AlbCre mouse by hepatic deletion of Keap1 in compound Keap1F/F::RbpjF/F::AlbCre mice. Unexpectedly, these mice developed higher hepatic and plasma cholesterol levels with more severe cholestatic liver damage during the pre-weaning period than in the RbpjF/F::AlbCre mice. In addition, hypercholesterolemia and hepatic damage were sustained throughout the growth period unlike in the RbpjF/F::AlbCre mouse. These enhanced abnormalities in lipid metabolism appear to be due to NRF2-dependent changes in gene expression related to cholesterol synthetic and subsequent bile acid production pathways. Notably, the hepatic expression of Cyp1A7 and Abcb11 genes involved in bile acid homeostasis was significantly reduced in Keap1F/F::RbpjF/F::AlbCre compared to RbpjF/F::AlbCre mice. The accumulation of liver cholesterol and the weakened capacity for bile excretion during the 3 pre-weaning weeks in the Keap1F/F::RbpjF/F::AlbCre mice may aggravate hepatocellular damage level caused by both excessive cholesterol and residual bile acid toxicity in hepatocytes. These results indicate that a tuned balance of NOTCH and NRF2 signaling is of biological importance for early liver development after birth.

Identification of ROS and KEAP1-related genes and verified targets of α-hederin induce cell death for CRC.

In this study, we analyzed and verified differentially expressed genes (DEGs) in ROS and KEAP1 crosstalk in oncogenic signatures using GEO data sets (GSE4107 and GSE41328). Multiple pathway enrichment analyses were finished based on DEGs. The genetic signature for colorectal adenocarcinoma (COAD) was identified by using the Cox regression analysis. Kaplan-Meier survival and receiver operating characteristic curve analysis were used to explore the prognosis value of specific genes in COAD. The potential immune signatures and drug sensitivity prediction were also analyzed. Promising small-molecule agents were identified and predicted targets of α-hederin in SuperPred were validated by molecular docking. Also, expression levels of genes and Western blot analysis were conducted. In total, 48 genes were identified as DEGs, and the hub genes such as COL1A1, CXCL12, COL1A2, FN1, CAV1, TIMP3, and IGFBP7 were identified. The ROS and KEAP1-associated gene signatures comprised of hub key genes were developed for predicting the prognosis and evaluating the immune cell responses and immune infiltration in COAD. α-hederin, a potential anti-colorectal cancer (CRC) agent, was found to enhance the sensitivity of HCT116 cells, regulate CAV1 and COL1A1, and decrease KEAP1, Nrf2, and HO-1 expression significantly. KEAP1-related genes could be an essential mediator of ROS in CRC, and KEAP1-associated genes were effective in predicting prognosis and evaluating individualized CRC treatment. Therefore, α-hederin may be an effective chemosensitizer for CRC treatments in clinical settings.

FGFR2-triggered autophagy and activation of Nrf-2 reduce breast cancer cell response to anti-ER drugs.

BACKGROUND: Genetic abnormalities in the FGFR signalling occur in 40% of breast cancer (BCa) patients resistant to anti-ER therapy, which emphasizes the potential of FGFR-targeting strategies. Recent findings indicate that not only mutated FGFR is a driver of tumour progression but co-mutational landscapes and other markers should be also investigated. Autophagy has been recognized as one of the major mechanisms underlying the role of tumour microenvironment in promotion of cancer cell survival, and resistance to anti-ER drugs. The selective autophagy receptor p62/SQSTM1 promotes Nrf-2 activation by Keap1/Nrf-2 complex dissociation. Herein, we have analysed whether the negative effect of FGFR2 on BCa cell response to anti-ER treatment involves the autophagy process and/or p62/Keap1/Nrf-2 axis. METHODS: The activity of autophagy in ER-positive MCF7 and T47D BCa cell lines was determined by analysis of expression level of autophagy markers (p62 and LC3B) and monitoring of autophagosomes' maturation. Western blot, qPCR and proximity ligation assay were used to determine the Keap1/Nrf-2 interaction and Nrf-2 activation. Analysis of 3D cell growth in Matrigel® was used to assess BCa cell response to applied treatments. In silico gene expression analysis was performed to determine FGFR2/Nrf-2 prognostic value. RESULTS: We have found that FGFR2 signalling induced autophagy in AMPKα/ULK1-dependent manner. FGFR2 activity promoted dissociation of Keap1/Nrf-2 complex and activation of Nrf-2. Both, FGFR2-dependent autophagy and activation of Nrf-2 were found to counteract the effect of anti-ER drugs on BCa cell growth. Moreover, in silico analysis showed that high expression of NFE2L2 (gene encoding Nrf-2) combined with high FGFR2 expression was associated with poor relapse-free survival (RFS) of ER+ BCa patients. CONCLUSIONS: This study revealed the unknown role of FGFR2 signalling in activation of autophagy and regulation of the p62/Keap1/Nrf-2 interdependence, which has a negative impact on the response of ER+ BCa cells to anti-ER therapies. The data from in silico analyses suggest that expression of Nrf-2 could act as a marker indicating potential benefits of implementation of anti-FGFR therapy in patients with ER+ BCa, in particular, when used in combination with anti-ER drugs.

[Antioxidant activity of Euryale ferox seed shell extract and its therapeutic effects on oral ulcer in rats].

OBJECTIVE: To investigate the therapeutic effect of Euryale ferox seed shell extract on oral ulcer in rats and its underlying mechanism. METHODS: The contents of polyphenols and flavonoids in Euryale ferox seed shells were determined by Folin-phenol assay and aluminum nitrate colorimetry, respectively. DPPH·, ABTS+·, ·OH and·O2- scavenging experiments were performed to evaluate the antioxidant activities of Euryale ferox seed shell extract in vitro. In a rat model of oral ulcer induced by burning with glacial acetic acid, the therapeutic effect of Euryale ferox seed shell extract was assessed by detecting changes in serum levels of oxidative factors by enzyme-linked immunosorbent assay (ELISA) and observing pathological changes of the ulcerous mucosa using HE staining; the therapeutic mechanism of the extract was explored by detecting the expression levels of Keap1, Nrf2, Nes-Nrf2 and HO-1 proteins in ulcerous mucosa using Western blotting. RESULTS: The ethyl acetate extract of Euryale ferox seed shells contained 306.74±1.04 mg/g polyphenols and 23.43±0.61 mg/g flavonoids and had IC50 values for scavenging DPPH· and ABTS+· free radicals of 3.42 ± 0.97 µg/mL and 3.32 ± 0.90 µg/mL, respectively. In the rat models, the ethyl acetate extract significantly ameliorated oral mucosal ulcer, increased serum CAT level, and decreased serum MDA level. The protein expression levels of Nes-Nrf2 and HO-1 were increased and Keap1 protein expression was lowered significantly in the ulcerous mucosa of the rats after treatment with the extract (P<0.05 or 0.01). CONCLUSION: The therapeutic effect of Euryale ferox seed shell extract on oral ulcers in rats is mediated probably by activation of the Keap1/Nrf2/HO-1 signaling pathway.

Deuterium-Depleted Water in Cancer Therapy: A Systematic Review of Clinical and Experimental Trials.

Chemotherapy exhibits numerous side effects in anti-tumour therapy. The clinical experiments indicated that deuterium-depleted water (DDW) monotherapy or in combination with chemotherapy was beneficial in inhibiting cancer development. To further understand the potential mechanism of DDW in cancer therapy, we performed a systematic review. The data from experiments published over the past 15 years were included. PubMed, Cochrane and Web of Science (January 2008 to November 2023) were systemically searched. Fifteen studies qualified for review, including fourteen in vivo and in vitro trials and one interventional trial. The results showed that DDW alone or in combination with chemotherapy effectively inhibited cancer progression in most experiments. The combination treatment enhances the therapeutic effect on cancer compared with chemotherapeutic monotherapy. The inhibitory role of DDW in tumours is through regulating the reactive oxygen species (ROS)-related genes in Kelch-like ECH-associated protein 1 (Keap 1) and Nuclear erythroid 2-related factor 2 (Nrf2) signalling pathways, further controlling ROS production. An abnormal amount of ROS can inhibit the tumour progression. More extensive randomized controlled trials should be conducted to evaluate the accurate effect of DDW in Keap1-Nrf2 signalling pathways.

Melatonin ameliorates 10-hydroxycamptothecin-induced oxidative stress and apoptosis via autophagy-regulated p62/Keap1/Nrf2 pathway in mouse testicular cells.

10-Hydroxycamptothecin (HCPT) is a widely used clinical anticancer drug but has a significant side effect profile. Melatonin has a beneficial impact on the chemotherapy of different cancer cells and reproductive processes, but the effect and underlying molecular mechanism of melatonin's involvement in the HCPT-induced side effects in cells, especially in the testicular cells, are poorly understood. In this study, we found that melatonin therapy significantly restored HCPT-induced testicular cell damage and did not affect the antitumor effect of HCPT. Further analysis found that melatonin therapy suppressed HCPT-induced DNA damage associated with ataxia-telangiectasia mutated- and Rad3-related and CHK1 phosphorylation levels in the testis. Changes in apoptosis-associated protein levels (Bax, Bcl-2, p53, and Cleaved caspase-3) and in reactive oxygen species-associated proteins (Nrf2 and Keap1) and index (malondialdehyde and glutathione) suggested that melatonin treatment relieved HCPT-induced cell apoptosis and oxidative damage, respectively. Mechanistically, melatonin-activated autophagy proteins (ATG7, Beclin1, and LC3bII/I) may induce p62-dependent autophagy to degrade Keap1, eliciting Nrf2 from Keap1-Nrf2 interaction to promote antioxidant enzyme expression such as HO-1, which would salvage HCPT-induced ROS production and mitochondrial dysfunction. Collectively, this study reveals that melatonin therapy may protect testicular cells from HCPT-induced damage via the activation of autophagy, which alleviates oxidative stress, mitochondrial dysfunction, and cell apoptosis.

Cynarin alleviates acetaminophen-induced acute liver injury through the activation of Keap1/Nrf2-mediated lipid peroxidation defense via the AMPK/SIRT3 signaling pathway.

Overdose of Acetaminophen (APAP) is a major contributor to acute liver injury (ALI), a complex pathological process with limited effective treatments. Emerging evidence links lipid peroxidation to APAP-induced ALI. Cynarin (Cyn), a hydroxycinnamic acid derivative, exhibits liver protective effects, but whether it mitigates APAP-induced ALI is unclear. Our aim was to verify the protective impact of Cyn on APAP-induced ALI and elucidate the molecular mechanisms governing this process. Herein, the regulation of the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) interaction was determined to be a novel mechanism underlying this protective impact of Cyn against APAP-induced ALI. Nrf2 deficiency increased the severity of APAP-induced ALI and lipid peroxidation and counteracted the protective effect of Cyn against this pathology. Additionally, Cyn promoted the dissociation of Nrf2 from Keap1, enhancing the nuclear translocation of Nrf2 and the transcription of downstream antioxidant proteins, thereby inhibiting lipid peroxidation. Molecular docking demonstrated that Cyn bound competitively to Keap1, and overexpression of Keap1 reversed Nrf2-activated anti-lipid peroxidation. Additionally, Cyn activated the adenosine monophosphate-activated protein kinase (AMPK)/sirtuin (SIRT)3 signaling pathway, which exhibits a protective effect on APAP-induced ALI. These findings propose that Cyn alleviates APAP-induced ALI by enhancing the Keap1/Nrf2-mediated lipid peroxidation defense via activation of the AMPK/SIRT3 signaling pathway.

Interaction with B-type lamin reveals the function of Drosophila Keap1 xenobiotic response factor in nuclear architecture.

BACKGROUND: The Keap1-Nrf2 pathway serves as a central regulator that mediates transcriptional responses to xenobiotic and oxidative stimuli. Recent studies have shown that Keap1 and Nrf2 can regulate transcripts beyond antioxidant and detoxifying genes, yet the underlying mechanisms remain unclear. Our research has uncovered that Drosophila Keap1 (dKeap1) and Nrf2 (CncC) proteins can control high-order chromatin structure, including heterochromatin. METHODS AND RESULTS: In this study, we identified the molecular interaction between dKeap1 and lamin Dm0, the Drosophila B-type lamin responsible for the architecture of nuclear lamina and chromatin. Ectopic expression of dKeap1 led to an ectopic localization of lamin to the intra-nuclear area, corelated with the spreading of the heterochromatin marker H3K9me2 into euchromatin regions. Additionally, mis-regulated dKeap1 disrupted the morphology of the nuclear lamina. Knocking down of dKeap1 partially rescued the lethality induced by lamin overexpression, suggesting their genetic interaction during development. CONCLUSIONS: The discovered dKeap1-lamin interaction suggests a novel role for the Keap1 oxidative/xenobiotic response factor in regulating chromatin architecture.

Neuroprotective effect of acetoxypachydiol against oxidative stress through activation of the Keap1-Nrf2/HO-1 pathway.

BACKGROUND: Excessive oxidative stress in the brain is an important pathological factor in neurological diseases. Acetoxypachydiol (APHD) is a lipophilic germacrane-type diterpene extracted as a major component from different species of brown algae within the genus Dictyota. There have been no previous reports on the pharmacological activity of APHD. The present research aims to explore the potential neuroprotective properties of APHD and its underlying mechanisms. METHODS: The possible mechanism of APHD was predicted using a combination of molecular docking and network pharmacological analysis. PC12 cells were induced by H2O2 and oxygen-glucose deprivation/reoxygenation (OGD/R), respectively. Western blot, flow cytometry, immunofluorescence staining, and qRT-PCR were used to investigate the antioxidant activity of APHD. The HO-1 inhibitor ZnPP and Nrf2 gene silencing were employed to confirm the influence of APHD on the signaling cascade involving HO-1, Nrf2, and Keap1 in vitro. RESULTS: APHD exhibited antioxidant activity in both PC12 cells subjected to H2O2 and OGD/R conditions by downregulating the release of LDH, the concentrations of MDA, and ROS, and upregulating SOD, GSH-Px, and GSH concentrations. APHD could potentially initiate the Keap1-Nrf2/HO-1 signaling cascade, according to the findings from network pharmacology evaluation and molecular docking. Furthermore, APHD was observed to increase Nrf2 and HO-1 expression at both mRNA and protein levels, while downregulating the protein concentrations of Keap1. Both Nrf2 silencing and treatment with ZnPP reversed the neuroprotective effects of APHD. CONCLUSIONS: APHD activated antioxidant enzymes and downregulated the levels of LDH, MDA, and ROS in two cell models. The neuroprotective effect is presumably reliant on upregulation of the Keap1-Nrf2/HO-1 pathway. Taken together, APHD from brown algae of the genus Dictyota shows potential as a candidate for novel neuroprotective agents.

Cyperus peptide SFRWQ inhibits oxidation and inflammation in RAW264.7 cell model.

Oxidative stress can induce many diseases. Antioxidant peptides from food sources have the advantages of good safety, high activity, and good absorbability. In this study, a pentapeptide (SFRWQ; SER-PHE-ARG-TRP-GLN) was identified in a protein hydrolysate of Cyperus (Cyperus esculentus L.). Enzyme-linked immunosorbent assay (ELISA), real-time quantitative (qPCR), immunofluorescence and other techniques were used to evaluate the anti-inflammatory and antioxidant effects of SFRWQ. SFRWQ was found to have 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging ability, help increase superoxide dismutase (SOD) and catalase (CAT) levels in RAW264.7 cells, reduce reactive oxygen species (ROS) levels, and decrease tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) gene expression and secretion. The binding score of SFRWQ to recombinant Kelch-like ECH-associated protein 1 (Keap1) was greater than that of TX6. These findings suggest that SFRWQ activates the Keap1-Nrf2 cellular antioxidant signaling pathway. According to metabolomics studies, SFRWQ increased glutathione (GSH), glutathione disulfide (GSSG), and γ-glutamylcysteine levels and decreased the levels of Prostaglandin D2 (PGD2), Prostaglandin E2 (PGE2), and Prostaglandin H2 (PGH2), which are involved in arachidonic acid metabolism, to protect cells from LPS-induced damage. By elucidating the mechanism of action of SFRWQ, we provide a reference for the development of dietary antioxidant peptides.

Cullin 3 RING E3 ligase inactivation causes NRF2-dependent NADH reductive stress, hepatic lipodystrophy, and systemic insulin resistance.

Cullin RING E3 ligases (CRL) have emerged as key regulators of disease-modifying pathways and therapeutic targets. Cullin3 (Cul3)-containing CRL (CRL3) has been implicated in regulating hepatic insulin and oxidative stress signaling. However, CRL3 function in liver pathophysiology is poorly defined. Here, we report that hepatocyte Cul3 knockout results in rapid resolution of steatosis in obese mice. However, the remarkable resistance of hepatocyte Cul3 knockout mice to developing steatosis does not lead to overall metabolic improvement but causes systemic metabolic disturbances. Liver transcriptomics analysis identifies that CRL3 inactivation causes persistent activation of the nuclear factor erythroid 2-related factor 2 (NRF2) antioxidant defense pathway, which also reprograms the lipid transcriptional network to prevent TG storage. Furthermore, global metabolomics reveals that NRF2 activation induces numerous NAD+-consuming aldehyde dehydrogenases to increase the cellular NADH/NAD+ ratio, a redox imbalance termed NADH reductive stress that inhibits the glycolysis-citrate-lipogenesis axis in Cul3 knockout livers. As a result, this NRF2-induced cellular lipid storage defect promotes hepatic ceramide accumulation, elevates circulating fatty acids, and worsens systemic insulin resistance in a vicious cycle. Hepatic lipid accumulation is restored, and liver injury and hyperglycemia are attenuated when NRF2 activation and NADH reductive stress are abolished in hepatocyte Cul3/Nrf2 double-knockout mice. The resistance to hepatic steatosis, hyperglycemia, and NADH reductive stress are observed in hepatocyte Keap1 knockout mice with NRF2 activation. In summary, our study defines a critical role of CRL3 in hepatic metabolic regulation and demonstrates that the CRL3 downstream NRF2 overactivation causes hepatic metabolic maladaptation to obesity and insulin resistance.

Cancer-associated fibroblasts secrete FGF5 to inhibit ferroptosis to decrease cisplatin sensitivity in nasopharyngeal carcinoma through binding to FGFR2.

Cisplatin (DDP)-based chemoradiotherapy is one of the standard treatments for nasopharyngeal carcinoma (NPC). However, the sensitivity and side effects of DDP to patients remain major obstacles for NPC treatment. This research aimed to study DDP sensitivity regulated by cancer-associated fibroblasts (CAFs) through modulating ferroptosis. We demonstrated that DDP triggered ferroptosis in NPC cells, and it inhibited tumor growth via inducing ferroptosis in xenograft model. CAFs secreted high level of FGF5, thus inhibiting DDP-induced ferroptosis in NPC cells. Mechanistically, FGF5 secreted by CAFs directly bound to FGFR2 in NPC cells, leading to the activation of Keap1/Nrf2/HO-1 signaling. Rescued experiments indicated that FGFR2 overexpression inhibited DDP-induced ferroptosis, and CAFs protected against DDP-induced ferroptosis via FGF5/FGFR2 axis in NPC cells. In vivo data further showed the protective effects of FGF5 on DDP-triggered ferroptosis in NPC xenograft model. In conclusion, CAFs inhibited ferroptosis to decrease DDP sensitivity in NPC through secreting FGF5 and activating downstream FGFR2/Nrf2 signaling. The therapeutic strategy targeting FGF5/FGFR2 axis from CAFs might augment DDP sensitivity, thus decreasing the side effects of DDP in NPC treatment.

Resveratrol relieves HFD-induced insulin resistance in skeletal muscle tissue through antioxidant capacity enhancement and the Nrf2-Keap1 signaling pathway.

BACKGROUND: Resveratrol has received much attention due to its beneficial effects including antioxidant activity. The purpose of this study was to investigate the therapeutic effects of resveratrol treatment on oxidative stress and insulin resistance in the skeletal muscle of high-fat diet (HFD)-fed animals. METHODS AND RESULTS: A total of 30 six-week-old C57BL/6J mice were randomly allocated to three groups (10 animals in each group): The control group in which mice were fed a normal chow diet (NCD); the HFD group in which mice were fed an HFD for 26 weeks; and the HFD-resveratrol group in which HFD was replaced by a resveratrol supplemented-HFD (400 mg/kg diet) after 10 weeks of HFD feeding. At the end of this period, gastrocnemius muscle samples were examined to determine insulin resistance and the oxidative status in the presence of HFD and resveratrol. Resveratrol supplementation in HFD-fed mice reduced body and adipose tissue weight, improved insulin sensitivity, and decreased oxidative stress as indicated by lower malonaldehyde (MDA) levels and higher total antioxidant capacity. The supplement also increased the expression and activity of antioxidative enzymes in gastrocnemius muscle and modulated Nrf2 and Keap1 expression levels. CONCLUSIONS: These results suggest that resveratrol is effective in improving the antioxidant defense system of the skeletal muscle in HFD-fed mice, indicating its therapeutic potential to combat diseases associated with insulin resistance and oxidative stress.

Role of kidney function on Nrf2 mRNA levels in type 2 diabetes.

INTRODUCTION: Diabetic kidney disease (DKD) is a major complication in patients with diabetes and the main contributor to the chronic kidney disease (CKD) global burden. Oxidative stress is a crucial factor in DKD pathogenesis but the role of the antioxidant nuclear factor erythroid 2-related factor 2 (Nrf2) and its molecular regulators has been poorly investigated in man. RESEARCH DESIGN AND METHODS: In this case-control study, we analyzed the roles of Nrf2, a transcription factor shielding cells from oxidative stress, its repressor Kelch-like ECH-associated protein 1 (Keap1) and six microRNAs (miRNAs) that potentially suppress Nrf2. We categorized 99 participants into 3 groups: 33 non-dialysis patients with type 2 diabetes with DKD, 33 patients with type 2 diabetes without DKD and 33 control subjects and quantified the gene expression (messenger RNA (mRNA)) levels of Nrf2, Keap1 and 6 miRNAs. Moreover, we studied the correlation between gene expression levels and clinical indicators of kidney health. RESULTS: In patients with diabetes with DKD, Nrf2 mRNA levels were significantly lower than in patients without DKD (p=0.01) and controls (p=0.02), whereas no difference in Nrf2 expression levels existed between patients without DKD and controls. Conversely, in patients with and without DKD, Keap1 expression levels were significantly higher than in controls. Of the six miRNAs studied, miRNA 30e-5p showed differential expression, being markedly reduced in patients with DKD (p=0.007). Nrf2 mRNA levels directly correlated with estimated glomerular filtration rate (eGFR) in patients with DKD (r=0.34, p=0.05) and in a formal mediation analysis the eGFR emerged as the first factor in rank for explaining the difference in Nrf2 mRNA levels between patients with and without DKD. CONCLUSIONS: The observed dysregulation in the Nrf2-Keap1 axis and the unique expression pattern of miRNA30e-5p in DKD underscore the need for more focused research in this domain that can help identify novel intervention strategies for DKD in patients with type 2 diabetes.

Shizukaol C alleviates trimethylamine oxide-induced inflammation through activating Keap1-Nrf2-GSTpi pathway in vascular smooth muscle cell.

BACKGROUND: Cardiovascular disease is one of the main causes of global mortality, and there is an urgent need for effective treatment strategies. Gut microbiota-dependent metabolite trimethylamine-N-oxide (TMAO) promotes the development of cardiovascular diseases, and shizukaol C, a natural sesquiterpene isolated from Chloranthus multistachys with various biological activities, might exhibit beneficial role in preventing TMAO-induced vascular inflammation. PURPOSE: The purpose of this study was to investigate the anti-inflammatory effects and the underlying mechanisms of shizukaol C on TMAO-induced vascular inflammation. METHODS: The effect and underlying mechanism of shizukaol C on TMAO-induced adhesion molecules expression, bone marrow-derived macrophages (BMDM) adhesion to VSMC were evaluated by western blot, cell adhesion assay, co-immunoprecipitation, immunofluorescence assay, and quantitative Real-Time PCR, respectively. To verify the role of shizukaol C in vivo, TMAO-induced vascular inflammation model were established using guidewire-induced injury on mice carotid artery. Changes in the intima area and the expression of GSTpi, VCAM-1, CD68 were examined using haematoxylin-eosin staining, and immunofluorescence assay. RESULTS: Our data demonstrated that shizukaol C significantly suppressed TMAO-induced adhesion molecule expression and the bone marrow-derived macrophages (BMDM) adhesion in vascular smooth muscle cells (VSMC). Mechanically, shizukaol C inhibited TMAO-induced c-Jun N-terminal kinase (JNK)-nuclear factor-kappa B (NF-κB)/p65 activation, and the JNK inhibition was dependent on the shizukaol C-mediated glutathione-S-transferase pi (GSTpi) expression. By further molecular docking and protein-binding analysis, we demonstrated that shizukaol C directly binds to Keap1 to induce Nrf2 nuclear translocation and upregulated GSTpi expression. Consistently, our in vivo experiment showed that shizukaol C elevated the expression level of GSTpi in carotid arteries and alleviates TMAO-induced vascular inflammation. CONCLUSION: Shizukaol C exerts anti-inflammatory effects in TMAO-treated VSMC by targeting Keap1 and activating Nrf2-GSTpi signaling and resultantly inhibits the downstream JNK-NF-κB/p65 activation and VSMC adhesion, and alleviates TMAO-induced vascular inflammation in vivo, suggesting that shizukaol C may be a potential drug for treating TMAO-induced vascular diseases.

Differential squamous cell fates elicited by NRF2 gain of function versus KEAP1 loss of function.

Clinical evidence has revealed that high-level activation of NRF2 caused by somatic mutations in NRF2 (NFE2L2) is frequently detected in esophageal squamous cell carcinoma (ESCC), whereas that caused by somatic mutations in KEAP1, a negative regulator of NRF2, is not. Here, we aspire to generate a mouse model of NRF2-activated ESCC using the cancer-derived NRF2L30F mutation and cancer driver mutant TRP53R172H. Concomitant expression of NRF2L30F and TRP53R172H results in formation of NRF2-activated ESCC-like lesions. In contrast, while squamous-cell-specific deletion of KEAP1 induces similar NRF2 hyperactivation, the loss of KEAP1 combined with expression of TRP53R172H does not elicit the formation of ESCC-like lesions. Instead, KEAP1-deleted cells disappear from the esophageal epithelium over time. These findings demonstrate that, while cellular NRF2 levels are similarly induced, NRF2 gain of function and KEAP1 loss of function elicits distinct fates of squamous cells. The NRF2L30F mutant mouse model developed here will be instrumental in elucidating the mechanistic basis leading to NRF2-activated ESCC.

Binge alcohol induces NRF2-related antioxidant response in the skeletal muscle of female mice.

BACKGROUND: Chronic alcohol enhances oxidative stress, but the temporal response of antioxidant genes in skeletal muscle following a binge drinking episode remains unknown. METHODS: Experiment 1: C57BL/6Hsd female mice received an IP injection of saline (CON; n = 39) or ethanol (ETOH; n = 39) (5 g/kg). Gastrocnemius muscles were collected from baseline (untreated; n = 3), CON (n = 3), and ETOH (n = 3) mice every 4 h for 48 h. Experiment 2: Gastrocnemius muscles were collected from control-fed (CON-FED; n = 17), control-fasted (CON-FAST; n = 18), or alcohol-fed (ETOH-FED; n = 18) mice every 4hrs for 20hrs after saline or ethanol (5 g/kg). RESULTS: EtOH enhanced Superoxide dismutase 1 (Sod1) and NADPH Oxidase 4 (Nox4) from 24 to 48hr after the binge, while Sod2 and Nox2 were suppressed. Nuclear factor erythroid-derived 2-like 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1) increased 12hrs after intoxication. Cytochrome P450 oxidoreductase (Por), Heme oxygenase 1 (Ho1), Peroxiredoxin 6 (Prdx6), Glutamate-cysteine ligase catalytic subunit (Gclc), Glutamate-cysteine ligase modifier subunit (Gclm), and Glutathione-disulfide reductase (Gsr) were increased by ETOH starting 12-16hrs post-binge. Fasting had similar effects on Nrf2 compared to alcohol, but downstream targets of NRF2, including Por, Ho1, Gclc, and Gclm, were differentially altered with fasting and EtOH. CONCLUSION: These data suggest that acute alcohol intoxication induced markers of oxidative stress and antioxidant signaling through the NRF2 pathway and that there were effects of alcohol independent of a possible decrease in food intake caused by binge intoxication.

Upregulation of Nrf2 signaling: A key molecular mechanism of Baicalin's neuroprotective action against diabetes-induced cognitive impairment.

BACKGROUND AND AIM: Diabetes-associated cognitive impairment (DCI) is a prevalent complication of diabetes. However, there is a lack of viable strategies for preventing and treating DCI. This study aims to explore the efficacy of baicalin (Bai) in attenuating DCI and elucidating the underlying mechanisms. EXPERIMENTAL PROCEDURE: GK rats fed a high-fat and high-glucose diet were utilized to investigate the therapeutic potential of Bai. Cognitive function was assessed using the Morris water maze and novel object recognition tests. To gain insight into the molecular mechanisms underlying Bai's neuro-protective effects, co-cultured BV2/HT22 cells were established under high-glucose (HG) stimulation. The modes of action of Bai were subsequently confirmed in vivo using the DCI model in db/db mice. KEY RESULTS: Bai restored cognitive and spatial memory and attenuated neuron loss, along with reducing expressions of Aß and phosphorylated Tau protein in diabetic GK rats. At the cellular level, Bai exhibited potent antioxidant and anti-inflammatory effects against HG stimulation. These effects were associated with the upregulation of Nrf2 and supressed Keap1 levels. Consistent with these in vitro findings, similar mechanisms were observed in db/db mice. The significant neuroprotective effects of Bai were abolished when co-administered with ATRA, a Nrf2 blocker, in db/db mice, confirming that KEAP1-Nrf2 signaling pathway was responsible for the observed effect. CONCLUSIONS AND IMPLICATIONS: Bai demonstrates a great therapeutic potential for attenuating DCI. The antioxidant defense and anti-inflammatory actions of Bai were mediated through the KEAP1-Nrf2 axis. These findings advance our understanding of potential treatment approaches for DCI, a common complication associated with diabetes.

Αnti-prion effects of anthocyanins.

Prion diseases, also known as Transmissible Spongiform Encephalopathies (TSEs), are protein-based neurodegenerative disorders (NDs) affecting humans and animals. They are characterized by the conformational conversion of the normal cellular prion protein, PrPC, into the pathogenic isoform, PrPSc. Prion diseases are invariably fatal and despite ongoing research, no effective prophylactic or therapeutic avenues are currently available. Anthocyanins (ACNs) are unique flavonoid compounds and interest in their use as potential neuroprotective and/or therapeutic agents against NDs, has increased significantly in recent years. Therefore, we investigated the potential anti-oxidant and anti-prion effects of Oenin and Myrtillin, two of the most common anthocyanins, using the most accepted in the field overexpressing PrPScin vitro model and a cell free protein aggregation model. Our results, indicate both anthocyanins as strong anti-oxidant compounds, upregulating the expression of genes involved in the anti-oxidant response, and reducing the levels of Reactive Oxygen Species (ROS), produced due to pathogenic prion infection, through the activation of the Keap1-Nrf2 pathway. Importantly, they showcased remarkable anti-prion potential, as they not only caused the clearance of pathogenic PrPSc aggregates, but also completely inhibited the formation of PrPSc fibrils in the Cerebrospinal Fluid (CSF) of patients with Creutzfeldt-Jakob disease (CJD). Therefore, Oenin and Myrtillin possess pleiotropic effects, suggesting their potential use as promising preventive and/or therapeutic agents in prion diseases and possibly in the spectrum of neurodegenerative proteinopathies.

Meningioma achieves malignancy and erastin-induced ferroptosis resistance through FOXM1-AURKA-NRF2 axis.

The oncogene Aurora kinase A (AURKA) has been implicated in various tumor, yet its role in meningioma remains unexplored. Recent studies have suggested a potential link between AURKA and ferroptosis, although the underlying mechanisms are unclear. This study presented evidence of AURKA upregulation in high grade meningioma and its ability to enhance malignant characteristics. We identified AURKA as a suppressor of erastin-induced ferroptosis in meningioma. Mechanistically, AURKA directly interacted with and phosphorylated kelch-like ECH-associated protein 1 (KEAP1), thereby activating nuclear factor erythroid 2 related factor 2 (NFE2L2/NRF2) and target genes transcription. Additionally, forkhead box protein M1 (FOXM1) facilitated the transcription of AURKA. Suppression of AURKA, in conjunction with erastin, yields significant enhancements in the prognosis of a murine model of meningioma. Our study elucidates an unidentified mechanism by which AURKA governs ferroptosis, and strongly suggests that the combination of AURKA inhibition and ferroptosis-inducing agents could potentially provide therapeutic benefits for meningioma treatment.