Lower GSH Levels Research Articles

Introduced paeoniflorin reduces the main toxicity induced by diosbulbin B, the major toxic compound of Dioscorea bulbifera L.: involved inhibiting inflammation and ferroptosis

Rhizoma Dioscoreae Bulbiferae (HYZ) is a widely utilized herb in clinical practice, known for its significant biological activities. However, the associated hepatotoxicity poses limitations to its application. Our previous research indicated that the effective mitigation of HYZ-induced hepatotoxicity through the concoction with Radix Paeoniae Alba medicinal juice involves the incorporation of paeoniflorin (Pae) and a reduction in diosbulbin B (DB), the primary toxic compound in HYZ. This finding suggests that the introduced Pae may exert a direct attenuating effect on DB. In light of this, this study represents the first investigation into Pae’s detoxification effect against DB-induced hepatotoxicity after administration for 2 months in mice vivo while also exploring underlying mechanisms related to inflammation and ferroptosis based on network pharmacology results. Our findings demonstrate that Pae significantly alleviates DB-induced hepatotoxicity in a dose-dependent manner. Western blotting and ELISA analyses revealed that Pae effectively reversed elevated levels of hepatic inflammation-related markers—such as NF-κB, p38 MAPK, NLRP3, TNF-α, and IL-1β—as well as excessively high concentrations of ferroptosis-related MDA and Fe2+. Furthermore, it restored low levels of GSH, SOD, GPX4, and FTH1. In summary, introduced Pae substantially mitigated DB-induced hepatotoxicity by inhibiting both hepatocyte inflammation and ferroptosis.

Reactivation of MAPK-SOX2 pathway confers ferroptosis sensitivity in KRASG12C inhibitor resistant tumors

The clinical success of KRASG12C inhibitors (G12Ci) including AMG510 and MRTX849 is limited by the eventual development of acquired resistance. A novel and effective treatment to revert or target this resistance is urgent. To this end, we established G12Ci (AMG510 and MRTX849) resistant KRASG12C mutant cancer cell lines and screened with an FDA-approved drug library. We found the ferroptosis inducers including sorafenib and lapatinib stood out with an obvious growth inhibition in the G12Ci resistant cells. Mechanistically, the G12Ci resistant cells exhibited reactivation of MAPK signaling, which repressed SOX2-mediated expression of cystine transporter SLC7A11 and iron exporter SLC40A1. Consequently, the low intracellular GSH level but high iron content engendered hypersensitivity of these resistant tumors to ferroptosis inducers. Ectopic overexpression of SOX2 or SLC7A11 and SLC40A1 conferred resistance to ferroptosis in the G12Ci resistant cells. Ferroptosis induced by sulfasalazine (SAS) achieved obvious inhibition on the tumor growth of xenografts derived from AMG510-resistant KRASG12C-mutant cells. Collectively, our results suggest a novel therapeutic strategy to treat patients bearing G12Ci resistant cancers with ferroptosis inducers.

Protective role of SIRT1 (rs3758391 T > C) polymorphism against T2DM and its complications: Influence on GPx activity

AbstractBackground and AimsSirtuin‐1 (SIRT1) has antidiabetic effects through the regulation of insulin secretion and modulation of inflammation. The SIRT1 rs3758391 gene polymorphism affects the level of SIRT1. The current study aimed to investigate the possible influence of SIRT1 gene variants in relation to oxidative stress parameters on the susceptibility to type 2 diabetes mellitus (T2DM) and its microvascular complications.MethodsIn this case‐control study 398 individuals including 300 patients with T2DM (100 T2DM without complication, 100 diabetic neuropathy patients and 100 patients with diabetic retinopathy) and 98 healthy subjects were studied for SIRT1 rs3758391 T > C variants. Also, the glutathione peroxidase (GPx) activity and the levels of glutathione (GSH), malondialdehyde (MDA), total antioxidant capacity (TAC), and total oxidative status (TOS) were determined by colorimetric methods. SIRT1 genotypes were detected using the polymerase chain reaction‐restriction fragment length polymorphism method.ResultsThe C allele of SIRT1 reduced the risk of T2DM, diabetic neuropathy and diabetic retinopathy. Significantly lower levels of GSH, GPx, and TAC were found in diabetic patients compared to control group. However, the level of MDA was significantly higher in patients compared to healthy individuals. Considering all individuals, the GPx activity increased in the presence of the SIRT1 CC, and TC genotypes compared to the TT genotype. Among all studied individuals the activity of GPx was significantly higher in normal body mass index (BMI) subjects than overweight, and obese individuals. However, among overweight and obese diabetic, diabetic retinopathy and diabetic neuropathy patients the mean level of TOS was significantly higher compared to patients with normal BMI.ConclusionsOur findings suggest a protective role for SIRT1 C allele against T2DM and diabetic neuropathy and diabetic retinopathy. We found in the presence of this allele the GPx activity increased. Also, we detected an enhanced oxidative stress level among overweight and obese patients with diabetes and its complications that could be involved in the pathogenesis of the disease.

Changes in serum uric acid, glutathione, and amyloid-β1-42 levels in Parkinson’s disease patients and their association with disease progression and cognitive decline

Objective This study aims to evaluate the diagnostic significance of serum uric acid (UA), glutathione (GSH), and amyloid-β1-42 (Aβ1-42) levels in relation to disease progression and cognitive impairment in patients with Parkinson’s disease (PD). Methods A total of 209 PD patients with disease duration ranging from 4.0 to 6.8 years were enrolled. Based on the Hoehn-Yahr staging system, patients were classified into Early (n = 67), Medium-term (n = 70), and Advanced (n = 72) stages. Cognitive function was assessed using the Mini-Mental State Examination (MMSE), dividing the cohort into CD (cognitive dysfunction, n = 94) and NO-CD (no cognitive dysfunction, n = 115) groups. Serum UA, GSH, and Aβ1-42 levels were analyzed for correlations with clinical data. Independent risk factors and diagnostic value were determined through multivariable logistic regression models and receiver operating characteristic curve analysis. Results Serum UA and GSH levels progressively declined with advancing disease stage, while Aβ1-42 increased. Compared to the NO-CD group, the CD group showed lower serum UA and GSH levels, and higher Aβ1-42 levels. Serum UA and GSH were inversely correlated with disease duration, levodopa equivalent daily dose, and Unified Parkinson's Disease Rating Scale scores, while Aβ1-42 showed positive correlations. UA (p = 0.006), GSH (p < 0.001), and Aβ1-42 (p = 0.040) were independent predictors of disease stage. Similarly, UA (p = 0.003), GSH (p < 0.001), and Aβ1-42 (p < 0.001) were independent predictors of cognitive dysfunction. The combined assessment of these markers demonstrated a higher area under the curve (AUC) than individual markers for disease and cognitive decline identification. Conclusions Serum UA, GSH, and Aβ1-42 are independent predictors of disease progression and cognitive decline in PD patients. Their combined use offers enhanced diagnostic accuracy for disease staging and cognitive impairment in PD.

A CC-Type Glutaredoxins GRX480 Functions in Cadmium Tolerance by Maintaining Redox Homeostasis in Arabidopsis.

Cadmium (Cd) toxicity causes oxidative stress damage in plant cells. Glutaredoxins (GRXs), a type of small oxidoreductase, play a crucial role in modulating thiol redox states. However, whether GRXs act in Cd stress remains to be identified. Here, we reveal that Arabidopsis GRX480, a member of the CC-type family, enhances plant Cd stress tolerance. The GRX480 mutants exhibit enhanced sensitivity to Cd stress, manifested by shortened root, reduced biomass, lower chlorophyll and proline levels, and decreased photosynthetic efficiency compared with the wild type. The Cd concentration in GRX480 mutants is higher than the wild type, resulting from the inhibition of Cd efflux and transport genes transcription. Lower levels of GSH were detected in Cd-treated GRX480 mutants than in the wild type, indicating that GRX480 regulates plant Cd tolerance by influencing the balance between GSH and GSSG. Furthermore, the hyperaccumulation of reactive oxygen species (ROS) is associated with decreased expression of H2O2 scavenging genes in Cd-treated GRX480 mutants. Additionally, more toxic reactive carbonyl species (RCS), produced during oxidative stress, accumulate in Cd-treated GRX480 mutants than in wild type. Overall, our study establishes a critical role of GRX480 in response to Cd stress, highlighting its multifaceted contributions to detoxification and the maintenance of redox homeostasis.

Influence of Loading Density and Gender on the Welfare and Meat Quality of Horses During Transport for Slaughter.

The aim of this study was to determine the effects of loading density and gender on blood welfare indicators, carcass bruises and horsemeat quality. Data were collected from twelve transports of 89 slaughter horses originating from the same collection centre. The transportation of slaughter horses at high loading densities (>200 kg/m2), especially stallions, resulted in increased levels of lactate (p = 0.021), glucose (p < 0.0001), ceruloplasmin (p < 0.0001) and AOPP (p < 0.0001), but lower GSH levels (p < 0.0001). Compared to stallions and mares, geldings subjected to high loading density (>200 kg/m2) during transport had lower levels of the aforementioned blood metabolites. In addition, stallions exposed to a high load density (>200 kg/m2) had the highest frequency of severe (p = 0.0002), large (p < 0.0001) and circular (p = 0.0001) carcass bruises, which were predominantly located on the abdominal (p = 0.0056) and thoracic (p = 0.0004) wall. In contrast, a higher percentage (p < 0.0001) of undamaged carcasses was found in slaughter horses exposed to a low loading density (≤200 kg/m2) during transport. Stallions exposed to high loading densities (>200 kg/m2) during transport had the highest initial pH (p < 0.0001) and ultimate pH (p = 0.005) in terms of m. longissimus lumborum and redness (p = 0.017), but the lowest drip loss (p = 0.050) and lightness (p < 0.0001), which, consequently, led to the highest (p = 0.0045) proportion of DFD-like defects in the meat quality. In conclusion, the results of this study showed that high loading densities (>200 kg/m2), regardless of gender, negatively affect horse welfare during transport. In addition, stallions were more sensitive to poor pre-slaughter conditions and produced the lowest meat quality, while geldings were the most resistant. To determine the optimal transport density, further research is needed to determine the effects of different loading densities on the behaviour, physiology, carcass and meat quality of slaughter horses.

Glutathione and Selenium Supplementation Attenuates Liver Injury in Diethylnitrosamine-Induced Hepatocarcinogenic Mice by Enhancing Glutathione-Related Antioxidant Capacities.

Excess oxidative stress and inadequate antioxidant capacities are critical features in the development of hepatocellular carcinoma. This study aimed to determine whether supplementation with glutathione (GSH) and/or selenium (Se), as antioxidants, attenuates diethylnitrosamine (DEN)-induced hepatocarcinogenesis in mice. C57BL/6J male mice were randomly assigned to control, DEN, DEN + GSH, DEN + Se, and DEN + GSH + Se groups for 20 weeks. Daily supplementation with GSH and/or Se commenced in the first experimental week and continued throughout the study. DEN was administered in weeks 2-9 and 16-19 of the experimental period. DEN administration induced significant pathological alterations of hepatic foci, evidenced by elevated levels of liver function, accompanied by high malondialdehyde (MDA) levels; low GSH levels; and glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST) activities. Supplementation with GSH and Se significantly ameliorated liver pathological changes, reducing liver function and MDA levels while increasing GSH levels and GPx, GR, and GST activities. Notably, combined supplementation with GSH and Se more effectively increased the GSH/glutathione disulfide ratio and GPx activity than individual supplementation. Supplementation with GSH and Se attenuated liver injury in DEN-induced hepatocarcinogenic mice by enhancing GSH and its related antioxidant capacities, thereby mitigating oxidative damage.

Hematopoietic cells emerging from hemogenic endothelium exhibit lineage-specific oxidative stress responses

During human embryogenesis, distinct waves of hematopoiesis give rise to various blood cell types, originating from hemogenic endothelial (HE) cells. As HE cells reside in hypoxic conditions in the embryo, we investigated the role of hypoxia in human EHT and subsequent hematopoiesis. Using single-cell RNA sequencing we describe hypoxia-related transcriptional changes in different HE-derived blood lineages, which reveal that erythroid cells are particularly susceptible to oxidative stress, due to decreased NRF2 activity in hypoxia. In contrast, non-erythroid CD45+ cells exhibit increased proliferative rates in hypoxic conditions and enhanced resilience to oxidative stress. We find that even in normoxia, erythroid cells present a clear predisposition to oxidative stress, with low GSH levels and high lipid peroxidation, in contrast to CD45+ cells. Intriguingly, ROS is produced at different sites in GPA+ and CD45+ cells, revealing differences in OXPHOS and the use of canonical vs. non-canonical TCA cycle in these lineages. Our findings elucidate how hypoxia and oxidative stress distinctly affect HE-derived hematopoietic lineages, uncovering critical transcriptional and metabolic pathways that influence blood cell development.

Punica granatum L. peel extract protects diabetic nephropathy by activating the Nrf-2/HO-1 pathway.

Diabetes raises cardiovascular morbidity and mortality worldwide and causes retinopathy, neuropathy, and nephropathy. Punica granatum L. (Pomegranate) is a fruit that has been used for its medicinal properties in various cultures. This article aims to investigate the antioxidant, anti-inflammatory, anti-apoptotic activity of Punica granatum L. peel ethanol extract (PGE) and its efficacy on NF-κB and Nrf-2/HO-1 signaling pathways in kidney tissue of rats with streptozotocin-induced diabetes. Single dose STZ 60mg/kg/i.p. rats were given to induce diabetes and blood glucose measurements were taken 7 days later. PGE 10mg/kg/p.o. administered to the treatment groups for 20 days. Blood, kidney, and pancreas samples taken from anesthetized rats were analyzed biochemically and histopathologically. It was observed that STZ increased the levels of urea, uric acid and creatine in the blood, while PGE significantly decreased these parameters. The diabetic group had higher MDA and lower renal tissue GSH level, CAT, GPx, and SOD activity than the control group. STZ also enhanced inflammation, apoptosis, Bax, Caspase-3, and NF-κB expression, and decreased Bcl-2, HO-1, and Nrf-2 expression. Experimental results showed that PGE has the potential to alleviate the harmful effects on the kidney and pancreas by altering the mentioned parameters in diabetic rats.

The impact of ACTH levels on neurotransmitters and antioxidants in patients with major depressive disorder: A novel investigation

BackgroundThe relationship between neurotransmitters and oxidative stress in Major Depressive Disorder (MDD) patients, considering HPA axis activity and psychological and cognitive states, is unclear. This study examines changes in neurotransmitters (GABA, Glx) and antioxidants (GSH) in the dorsal anterior cingulate cortex (dACC) of MDD patients under varying levels of ACTH, and their relationship with psychological and cognitive conditions. MethodsForty-five MDD patients were divided into high-ACTH (>65 pg/mL; n = 16) and normal-ACTH (7–65 pg/mL; n = 29) groups based on blood ACTH levels, along with 12 healthy controls (HC). All participants underwent HAM-D, HAM-A assessments, and most completed MMSE and MoCA tests. GABA+, Glx, and GSH levels in the dACC were measured using the MEGA-PRESS sequence. Intergroup differences and correlations between clinical factors, HPA axis activity, and metabolites were analyzed. ResultsCompared to HC, the normal ACTH group showed higher Glx and lower GSH levels. Glx and GSH were negatively correlated with MDD severity. In the high-ACTH MDD group, Glx positively correlated with delayed memory, and GSH positively correlated with abstraction. Factors influencing GABA included ACTH levels, depression duration, and negative events. Predictive factors for HAM-D scores were GSH and GABA. LimitationsThe sample size is small. ConclusionMDD patients exhibit neurochemical differences in the brain related to HPA axis levels, MDD severity, and cognitive function. Clinical factors, neurotransmitters, and neuroendocrine levels significantly influence depression severity.

Lower distress intolerance is associated with higher glutathione levels in adolescent cannabis users

Cannabis (CB) use and psychological stressors increase oxidative stress in the brain. Glutathione (GSH), the most abundant antioxidant in the brain, protects against oxidative stress. Furthermore, distress intolerance, the inability to tolerate psychological or physiological stress is a risk factor for CB use. The relationship between CB use, brain GSH levels and distress intolerance remains unknown. Therefore, we examined GSH levels in the anterior cingulate cortex (ACC), as a measure of oxidative stress, and its relationship with distress intolerance in adolescent CB users and healthy controls (HC).Sixteen HC and 17 CB-using adolescents were included in the analysis. GSH levels were measured in the ACC using a metabolite-edited proton magnetic resonance spectroscopy sequence on a 3T scanner. Distress intolerance was assessed using the Distress Intolerance Index (DII) and CB use was evaluated using a structured clinical interview.In the CB group, lower CSF-corrected GSH levels in the ACC were correlated with higher DII scores. However, no significant between group differences were observed for ACC CSF-corrected GSH levels or on DII scores. No significant correlations were observed in the HC group between GSH levels and DII.Our findings suggests that the association between lower GSH levels and greater distress intolerance in CB users might reflect alterations in the balance between protective and oxidative stress conditions linked to the ability to tolerate distress. Further examination into this relationship can provide important insights into neurobiological correlates and risk factors associated with CB use to help inform preventive and treatment targets in the future.

Bisphenol AF Caused Reproductive Toxicity in Rats and Cineole Co-Treatment Exhibited Protective Effect.

Bisphenol AF (BPAF) is increasingly used and now found in products intended for human consumption. The protective effect of 1,8-cineole (CIN) against BPAF-induced reproductive toxicity was investigated. Four groups were created, with each group consisting of eight rats: control, BPAF (200mg/kg), CIN (200mg/kg), and BPAF + CIN groups. The results demonstrated that the BPAF group exhibited a decline in testosterone levels and a decrease in sperm parameters compared with the control. Additionally, higher levels of MDA were observed, along with lower levels of GSH and GPx activity. CAT activity also decreased slightly. Tnf-α, Nf-κB levels were significantly higher, and caspase-3 expression was elevated, while PCNA expression decreased. BPAF significantly increased tissue degeneration compared with the control. However, the BPAF + CIN group showed statistically significant improvements in sperm parameters, except for concentration. They also exhibited an increase in testosterone levels and an improvement in MDA and GSH levels compared with the BPAF group. However, GPx activity partially enhanced. Tnf-α and Nf-κB levels were significantly reduced, and caspase-3 levels declined while PCNA and Bcl-2 levels increased. The Johnsen Testicular Biopsy score showed a substantial increase. Overall, these results suggest that CIN co-treatment in rats enhanced reproductive health and exhibited antioxidant, antiapoptotic, and anti-inflammatory properties against BPAF-induced testicular damage.

Effectiveness of setarud (IMOD™) in attenuating gentamicin-induced nephrotoxicity in male rats

BackgroundGentamicin (GEN) can have serious adverse effects including nephrotoxicity. Setarud (IMOD™) is a new herbal drug with beneficial immune effects, obtained by mixing Tanacetum vulgare (tansy), Rosa canina and Urtica dioica (nettle) extracts as well as selenium, flavonoids and carotenes. This novel study aims to evaluate the effectiveness of Setarud (IMOD™) in attenuating GEN-induced nephrotoxicity in male rats. Twenty-eight adult male Sprague Dawley rats (weighing 180–200 g) were randomly divided into four groups (7 rats in each group): Control, IMOD treated (20 mg/kg body weight), GEN treated (100 mg/kg body weight), and GEN + IMOD co-treated. Injections were done intraperitoneally for 12 days. Serum urea, creatinine (Cr), Cr clearance, malondialdehyde (MDA), reduced glutathione (GSH) level, and activities of antioxidant enzymes Peroxidase (POD), Catalase (CAT), and Glutathione peroxidase (GPx) were measured by the colorimetric method. Volume density of proximal convoluted tubule (PCT), tubular necrosis, tubular cast formation, and leukocytic infiltration were evaluated histopathologically.ResultsIn the GEN group, there were significantly higher serum urea, Cr, and MDA levels with lower Cr clearance, GSH levels, POD, GPx and CAT activities, and PCT volume density with presence of tubular necrosis compared to the control and IMOD groups (P < 0.05). Treatment with IMOD significantly reduced the levels of urea, Cr and MDA, and increased Cr clearance and the activities of POD and CAT enzymes (P < 0.05). No significant differences in the activity of GSH and GPx were reported in the GEN + IMOD co-treated group compared to the GEN group. Moreover, IMOD significantly ameliorated PCT volume density and renal lesions caused by GEN.ConclusionIMOD (20 mg/kg body weight) can attenuate GEN-induced nephrotoxicity in rats by inhibition of oxidative stress or increasing the normal activity of antioxidant enzymes. Further studies are recommended on the effects of different doses of IMOD.

Overexpressing the PRSS1 Protein Specifically in the Pancreatic Islets by Nano-Celery Provided Protection against Streptozotocin-Induced Diabetes Mellitus in Male Rat

The goal of this study was to find out how giving whole barley grain to rats that had been given streptozotocin (STZ) affected lipid peroxidation (LPO), the activities of antioxidant enzymes in erythrocytes, and the production of insulin genes in the pancreas. A single shot of STZ (60 mg/kg, i.p.) caused diabetes in the experiment. The oxidative stress was measured by the amount of LPO in the tissue, the amount of reduced glutathione (GSH), and the activities of SOD, CAT, GPx, and GR enzymes in erythrocytes. The most important things that were seen in diabetic control rats were higher blood sugar and LPO levels, lower GSH levels, and lower enzyme functions. When diabetic rats (group G2) were given barley seed whole grain by mouth for 30 days, their LPO level dropped significantly compared to rats that were given STZ (group G3). Furthermore, diabetic rats (group G4) that were fed barley had higher levels of both enzyme- and non-enzymatic antioxidants, as well as higher levels of insulin and regeneration (PRSS1) genes, compared to diabetic normal rats (group G2). The results make it clear that oxidative stress plays a part in causing diabetes and suggest that adding barley to an animal's diet might help protect them.

From balance to imbalance: disruption of plasma glutathione concentration in micropapillary thyroid carcinoma

BackgroundDespite the presence of evidence that establishes a strong correlation between oxidative stress and thyroid cancer, there exists a scarcity of research that investigates the specific role of glutathione as an important antioxidant in this particular context. The objective of this study was to assess the altered balance of oxidative stress in cases of thyroid cancer, which includes both papillary thyroid carcinoma (PTC) and micro PTC (mPTC), by examining and comparing the total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), reduced glutathione (GSH), oxidized glutathione (GSSG), and GSSG/GSH ratio with those of individuals diagnosed with multinodular goiter (MNG) as well as Healthy subjects.Materials and methodsPlasma samples were collected from 92 patients (23 mPTC, 23 PTC, 23 MNG, 23 Healthy). The levels of TAC, TOS, GSH, and GSSG were measured using a commercial assay kits, and the OSI and GSSG/GSH ratio were calculated for each sample. Statistical analyses were performed to compare the oxidative stress between the groups.ResultsThe plasma levels of TOS were significantly higher in the mPTC, PTC, and MNG groups compared to the Healthy individuals (p < 0.05). The OSI in the mPTC and PTC groups showed a significant increase compared to the Healthy group (p < 0.05). The levels of GSH in mPTC and PTC were markedly lower compared to the Healthy subjects (p < 0.01). Interestingly, the concentration of GSH in mPTC was found to be considerably lower than in PTC and MNG patients (p < 0.01).ConclusionThese findings indicate that GSH may be a useful biomarker for evaluating oxidative stress and antioxidant system status in patients with PTC, especially mPTC. Low levels of GSH may indicate increased levels of oxidative stress, which may contribute to the development and progression of mPTC to PTC.

Pro-Oxidant Auranofin and Glutathione-Depleting Combination Unveils Synergistic Lethality in Glioblastoma Cells with Aberrant Epidermal Growth Factor Receptor Expression.

Glioblastoma (GBM) is the most prevalent and advanced malignant primary brain tumor in adults. GBM frequently harbors epidermal growth factor receptor (EGFR) wild-type (EGFRwt) gene amplification and/or EGFRvIII activating mutation. EGFR-driven GBM relies on the thioredoxin (Trx) and/or glutathione (GSH) antioxidant systems to withstand the excessive production of reactive oxygen species (ROS). The impact of EGFRwt or EGFRvIII overexpression on the response to a Trx/GSH co-targeting strategy is unknown. In this study, we investigated Trx/GSH co-targeting in the context of EGFR overexpression in GBM. Auranofin is a thioredoxin reductase (TrxR) inhibitor, FDA-approved for rheumatoid arthritis. L-buthionine-sulfoximine (L-BSO) inhibits GSH synthesis by targeting the glutamate-cysteine ligase catalytic (GCLC) enzyme subunit. We analyzed the mechanisms of cytotoxicity of auranofin and the interaction between auranofin and L-BSO in U87MG, U87/EGFRwt, and U87/EGFRvIII GBM isogenic GBM cell lines. ROS-dependent effects were assessed using the antioxidant N-acetylsteine. We show that auranofin decreased TrxR1 activity and increased ROS. Auranofin decreased cell vitality and colony formation and increased protein polyubiquitination through ROS-dependent mechanisms, suggesting the role of ROS in auranofin-induced cytotoxicity in the three cell lines. ROS-dependent PARP-1 cleavage was associated with EGFRvIII downregulation in U87/EGFRvIII cells. Remarkably, the auranofin and L-BSO combination induced the significant depletion of intracellular GSH and synergistic cytotoxicity regardless of EGFR overexpression. Nevertheless, molecular mechanisms associated with cytotoxicity were modulated to a different extent among the three cell lines. U87/EGFRvIII exhibited the most prominent ROS increase, P-AKT(Ser-473), and AKT decrease along with drastic EGFRvIII downregulation. U87/EGFRwt and U87/EGFRvIII displayed lower basal intracellular GSH levels and synergistic ROS-dependent DNA damage compared to U87MG cells. Our study provides evidence for ROS-dependent synergistic cytotoxicity of auranofin and L-BSO combination in GBM in vitro. Unraveling the sensitivity of EGFR-overexpressing cells to auranofin alone, and synergistic auranofin and L-BSO combination, supports the rationale to repurpose this promising pro-oxidant treatment strategy in GBM.

Antioxidant Complex of the Black Sea Bivalve &lt;i&gt;Flexopecten glaber ponticus&lt;/i&gt; (Bucquoy, Dautzenberg et Dollfus, 1889) in Natural Habitat

The antioxidant (AO) defense complex in tissues of the scallop Flexopecten glaber ponticus (Bucquoy, Dautzenberg et Dollfus, 1889) from a natural habitat in the Black Sea was studied for the first time. The results indicated a pronounced tissue specificity of the scallop AO complex along with close levels of TBA-reactive substances in all the studied organs. In the gills of the scallop, the activity of glutathione reductase (GR), superoxide dismutase (SOD), and catalase was higher compared to the hepatopancreas. The activity of glutathione peroxidase (GP), GR, and catalase in the gills was higher than in the muscle. The reduced glutathione (GSH) reserve in the gills was lower than in the hepatopancreas. This indicated that both the glutathione system and the key antioxidant enzymes, SOD and catalase, significantly contributed to the antioxidant defense of the scallop gills. In the hepatopancreas, the level of glutathione was the highest and the activity of GP was high and similar to that in the gills. This reflects their significant role in the AO defense of this organ. However, the activity of GR, SOD, and catalase in the hepatopancreas was significantly lower than in the gills. The scallop muscle was characterized by the lowest GP activity and a low GSH level, close to that in the gills. The SOD activity in the muscle was comparable to its value in the gills, and the activity of catalase and GR was comparable to the values in the scallop hepatopancreas.

Abstract IA019: Identification of metabolic adaptation mechanisms that confer resistance to glutathione depletion in Ewing sarcoma

Abstract Aggressive cancer cells must overcome diverse stress forms in the tumor microenvironment and circulation, such as oxidative stress, to survive and metastasize. One adaptive process to counter oxidative stress is to upregulate glutathione (GSH), a tripeptide consisting of glutamate, cysteine, and glycine, which is a powerful antioxidant in cells, including in tumor cells. A rate-liming step in GSH production is the availability of the amino acid, cysteine. Tumor cells can either import cystine, a dimer of cysteine, through the xCT antiporter system, for conversion to the reduced cysteine monomer, or in some tumor types, they can synthesize cysteine de novo from methionine and serine through the transsulfuration pathway. GSH is not only critical for redox homeostasis, but is taken up into mitochondria where is acts as a source of sulphur to generate iron-sulphur (Fe-S) clusters that are essential for many mitochondrial enzymes including electron transport complexes. We wished to determine if Ewing sarcoma cells could tolerate reduced levels of GSH, using either xCT genetic or pharmacologic inhibition, or by blocking downstream enzymes in the GSH synthesis pathway, including GCLC using buthionine sulfoximine (BSO), or glutaminase using CB-839. To our surprise, we were able to generate BSO and CB-839 resistant cells with vanishingly low levels of GSH. These cells somehow maintained not only redox homeostasis, but also showed functional mitochondrial respiration (oxidative phosphorylation). We then performed CRISPR dropout screens to identify how these cells might be surviving in the absence of GSH, and to tease out specific dependencies of these BSO and CB-839 resistant cells. These studies revealed unexpected dependencies, and opportunities for synthetic lethal interventions, as will be discussed. Citation Format: Poul H. Sorensen, Hai-Feng Zhang, Christopher Hughes, Alberto Delaidelli, Samuel Aparicio. Identification of metabolic adaptation mechanisms that confer resistance to glutathione depletion in Ewing sarcoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr IA019.

Cu(II) complex that synergistically potentiates cytotoxicity and an antitumor immune response by targeting cellular redox homeostasis

Developing anticancer drugs with low side effects is an ongoing challenge. Immunogenic cell death (ICD) has received extensive attention as a potential synergistic modality for cancer immunotherapy. However, only a limited set of drugs or treatment modalities can trigger an ICD response and none of them have cytotoxic selectivity. This provides an incentive to explore strategies that might provide more effective ICD inducers free of adverse side effects. Here, we report a metal-based complex (Cu-1) that disrupts cellular redox homeostasis and effectively stimulates an antitumor immune response with high cytotoxic specificity. Upon entering tumor cells, this Cu(II) complex enhances the production of intracellular radical oxidative species while concurrently depleting glutathione (GSH). As the result of heightening cellular oxidative stress, Cu-1 gives rise to a relatively high cytotoxicity to cancer cells, whereas normal cells with low levels of GSH are relatively unaffected. The present Cu(II) complex initiates a potent ferroptosis-dependent ICD response and effectively inhibits in vivo tumor growth in an animal model (c57BL/6 mice challenged with colorectal cancer). This study presents a strategy to develop metal-based drugs that could synergistically potentiate cytotoxic selectivity and promote apoptosis-independent ICD responses through perturbations in redox homeostasis.

Chitosan and Grifola Frondosa nanoparticles insulate liver dysfunction in EAC-bearing mice.

Ehrlich ascites carcinoma (EAC) is a rapidly growing and undifferentiated tumor that can prompt oxidative stress and liver toxicity, whereas chitosan and Grifola Frondosa have widely recognized biological qualities. Therefore, our study designed to assess the potential ameliorative ability of chitosan nanoparticles (CS NPs) and Grifola Frondosa nanoparticles (GF-loaded casein NPs) on EAC-induced hepatic injury in mice. A total of 60 female albino mice were segregated into 6 groups (10 mice each), G1, control group; G2, CS NPs group; G3, GF-loaded casein NPs group; G4, EAC group; G5, EAC treated with CS NPs; G6, EAC treated with GF-loaded casein NPs. According to the findings, EAC considerably increased serum activities of ALT, AST, ALP as well as LDL, cholesterol, and triglycerides levels coincided with marked decrease in albumin and total protein content in liver tissue. At the same time, it drastically lowered GSH levels and catalase activity while significantly elevating MDA levels. In addition, EAC caused DNA damage and apoptosis by decreasing Bcl-2 while increasing p53 expressions. However, either CS NPs or GF-loaded casein NPs therapy improved liver architecture and functioning, increased antioxidant parameters, and prevented hepatocyte death in EAC mice. Our findings concluded that CS NPs and GF-loaded casein NPs have insulating functions against EAC-induced hepatic damage in mice.