Downregulation Of Nrf2 Research Articles

EGFR-targeting RNase A-cetuximab antibody-drug conjugate induces ROS-mediated apoptosis to overcome drug resistance in KRAS mutant cancer cells

Antibody-drug conjugates (ADCs) are an emerging strategy in cancer therapy, enhancing precision and efficacy by linking targeted antibodies to potent cytotoxic agents. This study introduces a novel ADC that combines ribonuclease A (RNase A) with cetuximab (Cet), an anti-EGFR monoclonal antibody, through a polyethylene glycol (PEG) linker (RN-PEG-Cet), aimed to induce apoptosis in KRAS mutant colorectal cancer (CRC) via a ROS-mediated pathway. RN-PEG-Cet was successfully synthesized and characterized for its physicochemical properties, retaining full enzymatic activity in RNA degradation and high binding affinity to EGFR. In KRAS mutant SW-480 cells, RN-PEG-Cet significantly reduced cell viability at lower doses, with an IC50 of 11.7 µg/mL at 72 h. Compared to free Cet, RN-PEG-Cet demonstrated a ~ 2-fold increase in apoptosis and a ~ 3.5-fold increase in ROS production. The conjugate also disrupted the Nrf2/Keap1 pathway, with a significant upregulation of Keap1 (FC = 3.7, p ≤ 0.01) and downregulation of Nrf2 (FC = 3.3, p < 0.01), highlighting its role in impairing antioxidant defenses and promoting ROS-mediated cytotoxicity. These findings emphasize the potential of RN-PEG-Cet as a novel therapeutic approach for KRAS mutant CRC, offering superior apoptosis induction and targeted cytotoxicity compared to conventional therapies. This ADC could represent a new strategy for improving CRC treatment outcomes by effectively overcoming resistance mechanisms.

Impact of Diphenyl Diselenide on Acute Ethanol-Induced Disruption of Antioxidant Defense and Inflammatory Gene Expression in Rats

Perturbation in antioxidant status which often leads to inflammation of liver cells and alteration in activities of purinergic enzymes are common outcomes of ethanol intoxication, this makes any compound that is able to prevent or repair the redox imbalances induced by alcohol intoxication a potential therapeutic measure. Hence, this study aims to assess the effect of diphenyl diselenide (DPDSe) on oxidative stress indicators, inflammatory genes and activities of purinergic enzymes in ethanol intoxicated male Wistar rats. 10mg/kg DPDSe was administered orally 30 minutes before and after a single dose of 13 ml/kg (28% ethanol solution) was given to the rats. Thereafter, the antioxidant status, activities of purinergic enzymes and expression of redox-sensitive genes in the rats were evaluated. It was observed that ethanol evoked high production of lipid peroxidation with concomitant decrease in thiol level, increased Nucleotidase and NTPDase activities, it also causes the downregulation of Nrf2 and upregulation of (NF-kB), however, pre- and post-treatment with DPDSe caused a reversal effects on the biochemical parameters and molecular parameters evaluated respectively. The reversal of ethanol-induced changes in biochemical parameters, expression of genes linked to inflammation and antioxidant status in the liver of acute ethanol intoxicated rats by DPDSe suggests that it has high prospect as a suitable therapeutic agent for hepatotoxicity linked with acute ethanol intoxication.

Mechanisms of Nrf2 suppression and Camkk1 upregulation in Echinococcus granulosus-induced bone loss.

Osteoclast differentiation is essential for maintaining bone metabolism, and its dysregulation, particularly in the context of Echinococcus granulosus (CE) infection, can lead to severe bone loss. This study explores a novel mechanism by which CE protoscolices (PSC) drive osteoclast differentiation through the inhibition of Nrf2, followed by the upregulation of Camkk1. Transcriptome sequencing revealed a significant down-regulation of Nrf2 in cells treated with PSC. This was confirmed by Western blot and Q-PCR assays showing reduced Nrf2 protein and gene levels. In vivo studies with Nrf2 knockout mice demonstrated that the absence of Nrf2 exacerbates bone loss induced by PSC in both the spine and lower limbs, as observed through Micro-CT imaging and TRAP staining.Further investigations identified Camkk1 as a key downstream target of Nrf2. Using high-throughput sequencing and CO-IP experiments, we established that Nrf2 directly interacts with and regulates Camkk1. Functional assays indicated that PSC-induced upregulation of Camkk1 is significantly enhanced by Nrf2 knockdown, while silencing Camkk1 alone inhibits osteoclast differentiation.The therapeutic potential of this pathway was evaluated by screening small molecule inhibitors of Camkk1, with Crenolani emerging as a potent compound. In vivo administration of Crenolani in PSC-treated mice significantly alleviated bone loss in a dose-dependent manner.These findings elucidate a crucial molecular mechanism in osteoclast differentiation driven by CE infection and propose a promising therapeutic strategy for combating CE-induced bone destruction. This study advances our understanding of bone.

Adipose tissue macrophages-derived exosomal MiR-500a-5p under high glucose promotes adipocytes inflammation by suppressing Nrf2 expression

BackgroundType 2 diabetes (T2DM) is a chronic metabolic disorder characterized by insulin resistance and chronic inflammation. Adipose tissue macrophages (ATMs), central players in mediating pro-inflammatory responses within adipose tissue, have been shown to influence insulin sensitivity through exosome secretion. While the role of macrophages-derived exosomal miRNA has been studied in various diseases, their pathogenic roles in T2DM, particularly ATMs-derived exosomal miRNA in adipose tissue inflammation, remain underexplored. ObjectivesThis study focuses specifically on T2DM, investigating the role of ATM-derived exosomal miRNAs in adipose tissue inflammation, a critical factor in the pathogenesis of T2DM. MethodsATM were isolated from visceral adipose tissues in patients with or without diabetes. Differentially expressed miRNAs in ATM-derived exosomes were predicted by high-throughput RNA sequencing. The RAW264.7 macrophages and 3T3-L1 preadipocytes was selected as a model system. Quantitative RT-PCR was used to assess miR-500a-5p expression. The direct binding of miR-500a-5p to Nrf2 mRNA 3′ UTR was verified by dual luciferase assay. ResultsMiR-500a-5p was also enriched in the exosomes of high-glucose-treated macrophages. Furthermore, these exosomes induced high expression of miR-500a-5p and activation of the NLRP3 inflammasome in adipocytes when co-cultured with them. Additionally, the reduction of miR-500a-5p expression in macrophages by using a miR-500a-5p inhibitor ameliorated the pro-inflammatory properties of the exosomes, and co-culturing these exosomes with adipocytes resulted in decreased expression of NLRP3 inflammasome-associated proteins in adipocytes. In contrast, induction of miR-500a-5p expression led to the opposite results. Moreover, the dual-luciferase assay confirmed that miR-500a-5p directly targeted the 3′ UTR of Nrf2 mRNA. Unlike miR-500a-5p, Nrf2 exhibited an anti-inflammatory response. ConclusionThe results indicate that ATM-derived exosomal miR-500a-5p promotes NLRP3 inflammasome activation and adipose tissue inflammation through down-regulation of Nrf2 in adipocytes.

Luciferase-Based Reporter System for Investigating GPx4-Mediated Ferroptosis and Its Therapeutic Implications in Diabetes.

Ferroptosis, a distinct form of regulated cell death, is characterized by iron-dependent lipid peroxide accumulation in cell membranes from dysregulated cellular iron homeostasis and compromised antioxidant defense mechanisms. Glutathione peroxidase 4 (GPx4) is crucial in the regulation of ferroptosis by controlling lipid peroxide accumulation. Recent research established the association of ferroptosis with several diseases, prompting investigation toward ferroptosis-targeted therapeutic approaches. However, there is a lack of sensor systems designed to evaluate ferroptosis modulation in intact cells. In this study, we developed a highly sensitive luciferase-based reporter system to study GPx4-mediated ferroptosis in cells. We constructed a novel vector flanking the GPx4 promoter driving luciferase gene expression, demonstrating ferroptosis-specific luciferase activity in transfected HEK293T cells. We established stable cells expressing the construct and optimized its suitability for high-throughput screening using well-established ferroptosis modulators. We identified eugenol, a phenolic compound, as a potent ferroptosis inhibitor using the developed reporter system. Eugenol demonstrated dose-dependent protection against ferroptosis-induced damage in pancreatic beta cells, as assessed by the expression of the key markers such as GPx4, SLC7A11, NRF2, and HO1. Further, we showed the regulation of iron levels and total iron-binding capacity of beta cells by eugenol in streptozotocin (STZ) -induced diabetic mice. Additionally, the diabetes-induced downregulation of GPx4 and antioxidant Nrf2 in pancreatic tissue was significantly mitigated by eugenol, as evidenced by both immunohistochemistry and gene expression analysis. This research validates the functionality of the ferroptosis sensor and offers an approach to develop antidiabetic therapy by targeting ferroptosis to protect beta-cell viability and function.

Chlorogenic acid improves urogenital dysfunction induced by exposure to ambient particulate matter.

Oxidative stress is a well-known underlying mechanism for several diseases in response to environmental pollution. Although there is a lack of evidence on the relationship between air pollution and an established risk factor for urogenital dysfunction. The aim of this study was to investigate the mechanism of particulate matter (PM) on urogenital function and evaluate the potential efficacy of chlorogenic acid (CGA) in preventing urogenital damage in rats. Forty Wistar rats were divided into five groups (n = 8): control, particulate matter exposure (animals were exposed to fine dust in an inhalation chamber for 4 weeks, 3 days a week, for 3 h, PM10 concentration adjusted to 500-2000 µg/m3), and particulate matter plus 3 concentrations of chlorogenic acid (100, 200, and 400 mg/kg, gavage, 4 weeks, 3 days a week). At the end of the study, kidney biomarkers, oxidative stress markers, antioxidant enzymes, the oxidation resistance 1 (OXR1) and its downstream gene expression, sperm count, gonadotropin hormones, and the structure of the kidney, epididymis, and seminal vesicle were evaluated in response to PM exposure and CGA treatment in all groups. The data obtained from the current study showed that PM exposure led to kidney dysfunction and inhibition of oligospermia through oxidative stress, as evidenced by an increase in MDA and a decrease in TAC, SOD, CAT, and GSH concentration levels in blood samples. These results were consistent with the down-regulation of OXR1, Nrf2, and P21 gene expression. In contrast, CGA improved urogenital biomarkers and histopathology structures of the kidney, epididymis, and seminal vesicle by enhancing antioxidant defense system enzymes and modulating the OXR1 signaling pathway. Our findings suggest that environmental air pollution contributes to kidney dysfunction and urogenital damage. Modulation of oxidative stress through the OXR1, P21, and Nrf2 signaling pathways may be the underlying mechanism. Furthermore, chlorogenic acid supplementation could be recommended as a new protective or treatment strategy to safeguard urogenital function against exposure to particulate matter.

SNORA71A Downregulation Enhances Gemcitabine Sensitivity in Gallbladder Cancer Cells by Inducing Ferroptosis Through Inhibiting the AKT/NRF2/GPX4 Pathway.

Previous findings have indicated a marked upregulation of SNORA71A in gallbladder cancer (GBC) tissues compared to normal samples. However, the precise role and molecular mechanisms of SNORA71A in GBC remain largely unknown. Moreover, gemcitabine (GEM) drug resistance has been found to lead to unfavorable outcomes and recurrence in GBC patients. Therefore, this study aims to investigate the impact of SNORA71A on GBC and explore its potential effects on the sensitivity of GBC cells to GEM. RT-qPCR was conducted to assess SNORA71A level in matched normal and GBC tissues. Cell proliferation was examined through CCK-8 and 5-ethynyl-2'-deoxyuridine (EdU) assays. Additionally, the expression of proteins in GBC cells was analyzed using western blot assay. The level of SNORA71A was notably higher in GBC tissues relative to normal tissues. SNORA71A overexpression led to increased GBC cell proliferation and invasion. Conversely, SNORA71A deficiency strongly suppressed GBC cell proliferation and invasion and triggered cell apoptosis and ferroptosis. Additionally, downregulation of SNORA71A obviously enhanced the antiproliferative and anti-invasive effects of GEM on GBC cells, whereas these changes were reversed by inhibiting ferroptosis. Furthermore, deficiency of SNORA71A further augmented the GEM-induced downregulation of p-Akt, Nrf2, and GPX4 in NOZ cells; however, these effects were reversed by ferroptosis inhibition. Collectively, these findings suggested that downregulation of SNORA71A may increase the sensitivity of GBC cells to GEM by triggering ferroptosis through inhibiting the AKT/NRF2/GPX4 signaling pathway.

Decreased Mrpl42 expression exacerbates myocardial ischemia and reperfusion injury by inhibiting mitochondrial translation

Mammalian mitochondrial DNA (mtDNA) encodes a total of 13 proteins, all of which are subunits of enzyme complexes of the oxidative phosphorylation. The mtDNA-encoded protein synthesis depends on the mitochondrial ribosomal proteins (MRPs), which assemble to form a specialized form of ribosome. Some mtDNA-encoded proteins have been reported to be reduced after myocardial ischemic injury. However, the molecular mechanisms responsible for this decrease and whether this decrease is involved in myocardial ischemia/reperfusion (I/R) injury remains unknown. Here, we found that the mtDNA-encoded protein levels were significantly decreased after I/R injury, while the mRNA levels of these genes were either increased or had no significant change. Subsequently, by querying and analyzing public database resources, we found that the expression of many mitochondrial translation-related proteins tended to decrease after myocardial infarction injury, and the reduction in the expression of these proteins was most obvious for Mrpl42. Furthermore, we found that cardiac Mrpl42 knockdown aggravated I/R-induced cardiac contractile dysfunction and cardiomyocyte death, while restoring Mrpl42 expression in the heart reduced I/R injury. Mrpl42 knockdown impaired the translation of mtDNA-encoded genes, ultimately led to aberrations in mitochondrial morphology and respiratory function. In addition, we found that the decrease in the expression of Mrpl42 after I/R injury was caused by the downregulation of Nrf2, which directly regulates Mrpl42 transcription. Our study revealed that ischemic downregulation of Mrpl42 expression and subsequent inhibition of mitochondrial translation contribute to cardiac I/R injury. Targeting Mrpl42 may be a novel therapeutic intervention for cardiac I/R injury and myocardial infarction.

Vinpocetine attenuates 5-fluorouracil-induced intestinal injury: role of the Keap1/Nrf2/HO-1, NF-κB/TLR4/SOCS3 and RIPK1/RIPK3/MLKL signals

Objectives 5-Fluorouracil (5-FU) is a chemotherapy drug commonly prescribed in cancer management. Unfortunately, intestinal mucositis restricts 5-FU clinical use. Vinpocetine (VNP) is a synthetic alkaloid that is derived from vincamine. Our study was conducted to elucidate the intestinal protective effects of VNP on 5-FU intestinal injury in rats and explore the underlying mechanisms. Materials and methods 5-FU was injected i.p. for five days, while VNP was given P.O (5 and 10 mg/kg). Results VNP effectively mitigates oxidative stress by a significant increase in GSH and SOD and decreasing MDA content mediated by Nrf2, HO-1 upregulation, and significant Keap1 downregulation. VNP mitigated inflammatory perturbations by decreasing MPO, TNF-α, IL-1β, and IL-6 facilitated by downregulating NF-κB and TLR4 and upregulating SOCS3 levels. In addition, the RIPK1, RIPK3, MLKL, and caspase-8 expression levels were significantly decreased, evidenced improvement of intestinal necroptosis by VNP. Conclusion Hence, VNP potently prevents intestinal injury induced by 5-FU by modulating Keap1/Nrf2/HO-1, NF-κB/TLR4/SOCS3, and RIPK1/RIPK3/MLKL signals.

High concentration hydrogen attenuates sepsis-induced acute kidney injury by promoting mitochondrial biogenesis and fusion

Sepsis is a major cause of mortality among critical patients. Acute kidney injury (AKI) is the common complication in patients with sepsis, characterized by rapid deterioration of renal function. The purpose of this study is to assess the impact of inhaling high concentration hydrogen on septic mice with AKI and to examine the involvement of mitochondria in this process. High concentration hydrogen does not cause hypoxia and can alleviate AKI and improve 7-day survival in septic mice. Inflammatory factors are markedly elevated in the serum and renal tissues in CLP group which are dramatically down-regulated by hydrogen. The activities of both antioxidant enzymes are significantly reduced after CLP, whereas hydrogen markedly increases the activities of SOD and CAT. MMP is found to be significantly lower in CLP group whereas this effect is reversed by hydrogen. The trend of ATP content in renal tissues corresponded with that of MMP. There is a substantial downregulation of PGC-1α, Nrf2, and TFAM protein in CLP group. Drp1 expression is significantly higher in CLP group compared to Sham group, while the opposite trend is observed for MFN2. Hydrogen can reverse these changes. Inhalation of high concentration hydrogen can improve acute kidney injury, 7-day survival, inflammatory response and oxidative stress in septic mice. The mechanism may be related to inhibit renal mitochondrial fission and promote mitochondrial fusion and biogenesis.

Deciphering the mechanisms underlying the neuroprotective potential of kaempferol: a comprehensive investigation.

Neurodegenerative disorders are characterized by neuronal degradation, dysfunction, or death within the CNS. Oxidative and inflammatory stress play crucial roles in the pathogenesis of various neurodegenerative diseases. The interplay between these stressors and dysregulated cellular signaling pathways contributes to neurodegeneration. Downregulation of NRF-2 compromises antioxidant defense, exacerbating neuronal damage, while increased TLR-4/MAPK and TLR-4/NF-κB signaling promotes neuroinflammation. Excessive ROS production by NADPH oxidase leads to oxidative damage and neuronal apoptosis. The strategies targeting NRF-2, TLR-4-mediated inflammatory stress, and NADPH oxidase activity promise to mitigate neuronal damage and halt the progression of the disease. Kaempferol is a flavonoid polyphenol antioxidant found abundantly in various fruits and vegetables, including apples, grapes, tomatoes, and broccoli. It is widely found in medicinal plants including Equisetum spp., Sophora japonica, Ginkgo biloba, and Euphorbia pekinensis (Rupr.). A substantial body of in vitro and in vivo evidences have demonstrated the neuroprotective potential of kaempferol against neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Kaempferol demonstrates multifaceted potential in mitigating neuroinflammation, apoptosis, and oxidative stress in different neurodegenerative diseases through the modulation of various pathways including NRF-2, NADPH oxidase, TLR-4/MAPK, and TLR-4/NF-κB. This review article was developed through a comprehensive analysis and interpretation of research published between 2009 and 2024, sourced from multiple scientific databases, including PubMed, Scopus, ScienceDirect, and Web of Science. This review aims to provide an in-depth overview of the neuroprotective effects of kaempferol, focusing on its underlying molecular mechanisms. A total of 24 research evidence were included to elucidate the molecular pathways by which kaempferol exerts its protective effects against neurodegenerative diseases.

Maternal Obesity Alters Placental and Umbilical Cord Plasma Oxidative Stress, a Cross-Sectional Study.

Maternal obesity has been shown to impair the oxidative status in the placenta and newborns, potentially leading to adverse pregnancy outcomes and long-term effects on the programming of offspring metabolic status. This study aimed to investigate the impact of maternal obesity on maternal and umbilical cord plasma oxidative status, as well as placental oxidative adaptation. Maternal obesity (n = 20), defined as a pre-pregnancy BMI ≥ 25 kg/m2, and maternal leanness (n = 20), defined as a pre-pregnancy BMI < 23 kg/m2, were the group categories used in this study. Both groups were matched according to gestational age at delivery. Maternal blood, umbilical cord blood, and placental tissue were collected to assess nutritional content (cholesterol, triglyceride, and protein), oxidative stress markers (MDA and protein carbonyl), and antioxidant activity (SOD and catalase). Placental protein expression (SOD2, catalase, UCP2, and Nrf2) was evaluated using Western blot analysis. Catalase activity in maternal plasma significantly increased in the maternal obesity group (p = 0.0200), with a trend toward increased MDA and protein carbonyl levels. In umbilical cord plasma, triglyceride, protein carbonyl, and catalase activity were significantly elevated in the maternal obesity group compared with the lean controls (p = 0.0482, 0.0291, and 0.0347, respectively). Placental protein expression analysis revealed significantly decreased SOD2 (p = 0.0011) and catalase (p < 0.0001), along with Nrf2 downregulation (p < 0.0001). An increase in mitochondrial antioxidant UCP2 expression was observed (p = 0.0117). The neonatal protein carbonyl levels positively correlated with placental protein carbonyl (r = 0.7405, p < 0.0001) and negatively correlated with maternal catalase activity (r = -0.4332, p = 0.0052). This study thus provides evidence that maternal obesity is associated with placental and fetal oxidative stress, alongside a concurrent increase in placental antioxidant UCP2 expression.

Borna disease virus 1 induces ferroptosis, contributing to lethal encephalitis.

Borna disease virus 1 (BoDV-1) is a neurotropic RNA virus that has been linked to fatal BoDV-1 encephalitis (BVE) in humans. Ferroptosis represents a newly recognized kind of programmed cell death that marked by iron overload and lipid peroxidation. Various viral infections are closely related to ferroptosis. However, the link between BoDV-1 infection and ferroptosis, as well as its role in BVE pathogenesis, remains inadequately understood. Herein, we used primary rat cortical neurons, human microglial HMC3 cells, and Sprague‒Dawley rats as models. BoDV-1 infection induced ferroptosis, as ferroptosis characteristics were detected (iron overload, reactive oxygen species buildup, decreased antioxidant capacity, lipid peroxidation, and mitochondrial damage). Analysis via qRT-PCR and Western blot demonstrated that BoDV-1-induced ferroptosis was mediated through Nrf2/HO-1/SLC7a11/GPX4 antioxidant pathway suppression. Nrf2 downregulation was due to BoDV-1 infection promoting Nrf2 ubiquitination and degradation. Following BoDV-1-induced ferroptosis, the PTGS2/PGE2 signaling pathway was activated, and various intracellular lipid peroxidation products and damage-associated molecular patterns were released, contributing to BVE occurrence and progression. More importantly, inhibiting ferroptosis or the ubiquitin‒proteasome system effectively alleviated BVE. Collectively, these findings demonstrate the interaction between BoDV-1 infection and ferroptosis and reveal BoDV-1-induced ferroptosis as an underlying pathogenic mechanism of BVE.

Ultrasonic-assisted extraction, structural analysis and antioxidative mechanism of polysaccharide from sunflower disc

The crude sunflower disc polysaccharide (SDP) was obtained by using ultrasonic assist hot water extraction. Homogeneous SDP was separated by DEAE-cellulose column and Sephacryl S-400 HR column. Its physical properties and antioxidant mechanism was studied. Results showed that extraction yield of SDP was 15.3 %, total sugar was 91.3 %, weight molecular weight (Mw) was7.46 × 103 Da, number-average molecular weight (Mn) was 6.16 × 103 Da and polydispersion coefficient (Mw/Mn) was 1.21. SDP was composed of galactose (Gal), fucose (Fuc), xylose (Xyl), glucose (Glc), arabinose (Ara), rhamnose (Rha), glucuronic acid (Gle-UA) and galacturonic acid (Ga-UA), and the ratio of substance were 1.77∶2.00∶4.55∶8.44∶9.57∶14.26∶2.13∶57.28. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results showed that smooth surface and structure of SDP was relatively dense, and some crystallization existed, but the crystallization was weak. Two-dimensional structure of SDP showed that the main chain →4)-α-d-GalpA-(1→, →3)-α-l-Araf-(1→, →2)-α-l-Rhap-(1→, →2, 4)-α-l-Rhap-(1→, →2, 4)-α-d-GlcpA-(1→ and →3, 6)-β-d-Galp-(1→ interconnection form. Results of in vitro and in vivo of SDP and its derivatives showed that a good antioxidant activity. In vitro antioxidant activity, the scavenging rates of ABTS+, ·OH, DPPH and superoxide anions were 95.8 %, 93.9 %, 93.6 % and 92.1 %, respectively, when treated with 3.2 mg/mL of SDP solution. The preliminary antioxidative mechanism results showed that SDP had a regulatory effects on the down-regulation of Nrf2, HO-1 and NQO1 proteins in RAW264.7 cells. Preliminary pharmacokinetic analysis showed that the SDP could be absorbed orally and reached its peak concentration in the blood at about 2 h. The content of polysaccharide in blood reached the peak value at 30 min and reached the lowest value at 8 h after intravenous injection.

TIGAR relieves PCOS by inhibiting granulosa cell apoptosis and oxidative stress through activating Nrf2

This study aimed to elucidate the role of TP53-induced glycolysis and apoptosis regulator (TIGAR) in polycystic ovary syndrome (PCOS). A rat model PCOS was constructed by subcutaneous injection with dehydroepiandrosterone (DHEA). Follicular atresia and reduced granular cells (GCs) in ovaries suggested successful modeling. The low expression of TIGAR was observed in ovarian tissue of PCOS rat. To explore the role of TIGAR in PCOS, lentivirus carrying the TIGAR were used to up-regulate TIGAR expression. TIGAR overexpression reduced the DHEA-induced increase of ovarian weight, the levels of estradiol (E2), and the ratio of luteinizing hormone/follicle-stimulating hormone (LH/FSH) in the serum, as well as improved the morphology of the follicle, especially increased the thickness of the GC layer, which attributed to the inhibition of apoptosis by TIGAR. In addition, high expression of TIGAR inhibited oxidative stress in ovaries of PCOS rat, as evidenced by decreased level of malondialdehyde (MDA), and reactive oxygen species (ROS), and enhanced activity of glutathione peroxidase (GPX) and superoxide dismutase (SOD). Mechanically, Nrf2/OH-1 signal pathway was activated by TIGAR. The effect of TIGAR on PCOS were verified in the primary rat GCs treated with dihydrotestosterone, but also the rescue experiment was performed. Downregulation of Nrf2 reversed the effects of TIGAR, indicating that TIGAR suppressed oxidative stress and GC apoptosis by activating Nrf2/OH-1 pathway in PCOS. Finally, non-targeted metabolomics revealed that TIGAR might affect the energy metabolic pathway, thereby altering the metabolic profile of primary rat GCs. This study provided new insights into the prevention and treatment of PCOS.

Tamarixetin Protects Chondrocytes against IL-1β-Induced Osteoarthritis Phenotype by Inhibiting NF-κB and Activating Nrf2 Signaling.

Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage breakdown and chronic inflammation in joints. As the most prevalent form of arthritis, OA affects around 600 million people globally. Despite the increasing number of individuals with OA risk factors, such as aging and obesity, there is currently no effective cure for the disease. In this context, this study investigated the therapeutic effects of tamarixetin, a flavonoid with antioxidative and anti-inflammatory properties, against OA pathology and elucidated the underlying molecular mechanism. In interleukin-1β (IL-1β)-treated chondrocytes, tamarixetin inhibited the OA phenotypes, restoring cell viability and chondrogenic properties while reducing hypertrophic differentiation and dedifferentiation. Tamarixetin alleviated oxidative stress via the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway activation and inhibited mitogen-activated protein kinase and nuclear factor-κB (NF-κB). Furthermore, tamarixetin attenuated pyroptosis, a programmed cell death caused by excessive inflammation, by suppressing inflammasome activation. We confirmed that the chondroprotective effects of tamarixetin are mediated by the concurrent upregulation of Nrf2 signaling and downregulation of NF-κB signaling, which are key players in balancing antioxidative and inflammatory responses. Overall, our study demonstrated that tamarixetin possesses chondroprotective properties by alleviating IL-1β-induced cellular stress in chondrocytes, suggesting its therapeutic potential to relieve OA phenotype.

Impacts of gentamycin toxicity: nephroprotective role of guarana through different signaling pathways.

Gentamicin is a widely used aminoglycosidic antibiotic since its discovery. Like any other medication gentamicin causes unwanted side effects such as hepatotoxicity and nephrotoxicity. This study aims to examine the antioxidant effect of the guarana seed extract in protecting renal tissue. Forty male mice were divided into four groups (group one was control with free access to food and water, group two was treated orally with 300mg/kg of guarana seed extract daily, group three was injected intraperitoneally with 100mg/kg of gentamicin daily and the fourth group was co-treated with both 300mg/kg of guarana seed extract orally and injected intraperitoneally with 100mg/kg of gentamicin daily) for two weeks. Serum levels of urea, creatinine, AST, ALT, IL-1β and IL-6 have significantly elevated in the gentamicin treated group and those changes were not found in the guarana co-treated group. In gentamicin treated mice, a significant reduction was observed in two antioxidants SOD and GPX accompanied by downregulation of Ho-1 and Nrf2 while, that did not happen in the guarana seed extract co-treated group. Histopathology and immunohistochemistry slides show that the guarana seed extract prevents degenerative and necrotic events in tubular epithelial tissues caused by gentamicin toxicity. In conclusion, current data suggest that gentamicin can damage renal tissues when given at 100mg/kg/day, however, the guarana seed extract may be capable of preventing that event when cotreated with the gentamicin as a supplement.

Chrysomycin A Reshapes Metabolism and Increases Oxidative Stress to Hinder Glioblastoma Progression.

Glioblastoma represents the predominant and a highly aggressive primary neoplasm of the central nervous system that has an abnormal metabolism. Our previous study showed that chrysomycin A (Chr-A) curbed glioblastoma progression in vitro and in vivo. However, whether Chr-A could inhibit orthotopic glioblastoma and how it reshapes metabolism are still unclear. In this study, Chr-A markedly suppressed the development of intracranial U87 gliomas. The results from airflow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) indicated that Chr-A improved the abnormal metabolism of mice with glioblastoma. Key enzymes including glutaminase (GLS), glutamate dehydrogenases 1 (GDH1), hexokinase 2 (HK2) and glucose-6-phosphate dehydrogenase (G6PD) were regulated by Chr-A. Chr-A further altered the level of nicotinamide adenine dinucleotide phosphate (NADPH), thus causing oxidative stress with the downregulation of Nrf-2 to inhibit glioblastoma. Our study offers a novel perspective for comprehending the anti-glioma mechanism of Chr-A, highlighting its potential as a promising chemotherapeutic agent for glioblastoma.

ShRNA-interfered of Nrf2 reveals a critical role for Keap1-Nrf2 signaling pathway during effects of zearalenone induced oxidative stress in IPEC-J2 cells.

This study aims to verify the protective effect of the Kelch-like ECH-associated protein1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways by studying the effect of plasmids containing Nrf2-small hairpin RNA (shRNA) interference down-regulation of Nrf2 on zearalenone (ZEA)-induced intestinal porcine epithelial cells (IPEC-J2) oxidative stress. We constructed an IPEC-J2 model that interferes with Nrf2 expression, set blank (control), negative control group (Sh-control), positive control group (Sh-Nrf2), and added 10, 20, and 40 μmol/L ZEA experimental group (Sh-Nrf2+ZEA10, Sh-Nrf2+ZEA20, and Sh-Nrf2+ZEA40). The study results showed that, compared with the Sh-Nrf2 group, ZEA significantly increased the apoptosis rate of IPEC-J2 in a time- and dose-dependent manner. Compared with the Sh-Nrf2 group, the activities of total superoxide dismutase and glutathione peroxidase and relative expressions of Keap1 at mRNA and protein level in the Sh-Nrf2+ZEA20 and Sh-Nrf2+ZEA40 groups were significantly reduced, the malondialdehyde level, and the fluorescence intensity around and within the nucleus of reactive oxygen species and Nrf2, and the relative expressions of Nrf2, quinone oxidoreductase 1, and hemeoxygenase 1 at mRNA and protein level significantly increased. These results further prove that interfering with the expression of Nrf2 in IPEC-J2 cells affected the activation of the Keap1-Nrf2 signaling pathway and reduced the ability of cells to resist ZEA-induced oxidative stress. Therefore, the Keap1-Nrf2 signaling pathway had an important protective effect in ZEA-induced intestinal oxidative stress.

Sofalcone attenuates neurodegeneration in MPTP-induced mouse model of Parkinson's disease by inhibiting oxidative stress and neuroinflammation.

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by oxidative stress and neuroinflammation. Sofalcone (SFC), a chalcone derivative known for its antioxidative and anti-inflammatory properties, is widely used clinically as a gastric mucosa protective agent. However, its therapeutic potential in PD remains to be fully explored. In this study, we investigated the neuroprotective effects of SFC in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model. We found that SFC ameliorated MPTP-induced motor impairments in mice, as assessed by the rotarod and wire tests. Moreover, SFC administration prevented the loss of dopaminergic neurons and striatal degeneration induced by MPTP. Subsequent investigations revealed that SFC reversed MPTP-induced downregulation of NRF2, reduced elevated levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and increased total antioxidant capacity (TAOC). Furthermore, SFC suppressed MPTP-induced activation of microglia and astrocytes, downregulated the pro-inflammatory cytokine TNF-α, and upregulated the anti-inflammatory cytokine IL-4. Additionally, SFC ameliorated the MPTP-induced downregulation of phosphorylation of Akt at Ser473. This study provides evidence for the neuroprotective effects of SFC, highlighting its antioxidative and anti-inflammatory properties and its role in Akt activation in the PD model. These findings underscore SFC's potential as a promising therapeutic candidate for PD, warranting further clinical investigation.