Reduced Glutathione Levels Research Articles

Nebivolol ameliorates sepsis-evoked kidney dysfunction by targeting oxidative stress and TGF-β/Smad/p53 pathway

Sepsis is a potential fetal organ destruction brought on through an overzealous immunologic reaction to infection, causing severe inflammation, septic shock, and damage to different organs. Although there has been progress in the identification and controlling of clinical sepsis, the fatality rates are still significant. This study, for the first time, intended to examine the possible ameliorative impact of Nebivolol, a β1-adrenergic antagonist antihypertensive drug, against nephrotoxicity resulted from cecal ligation and puncture (CLP)-induced sepsis in rats, on molecular basis. Sixty male Wistar albino rats were chosen. Oxidative stress indicators and biochemical markers of kidney activity were evaluated. Inflammatory mediators, fibrosis- and apoptosis-related proteins and gene expressions were investigated. Moreover, renal histopathological investigation was performed. CLP-induced nephrotoxicity characterized by markedly elevated serum levels of creatinine, blood urea nitrogen, uric acid, and renal malondialdhyde. On the other hand, it decreased serum total protein level, renal superoxide dismutase activity and reduced glutathione level. Additionally, it significantly elevated the renal inflammatory mediators (tumor necrosis factor-alpha, ilnerlukin (IL)-6, and IL-1β) and Caspase-3 protein, reduced IL-10 level, amplified the expression of transforming growth factor-beta 1 (TGF-β1), p-Smad2/3 and alpha-smooth-muscle actin proteins, downregulated the B cell lymphoma-2 (Bcl-2) gene and elevated the transcription of Bcl-2-associated X-protein (Bax), p53 and Nuclear factor-kappa B (NF-κB) genes. Furtheremor, kidney tissues exhibited significant histopathological changes with CLP. On the contrary, Nebivolol significantly improved all these biochemical changes and enhanced the histopathological alterations obtained by CLP. This research showed, for the first time, that Nebivolol effectively mitigated the CLP-induced kidney dysfunction via its antioxidant, antifibrotic and anti-apoptotic activity through modulation of oxidative stress, TGF-β/NF-κB and TGF-β/Smad/p53 signaling pathways.

Aging exacerbates oxidative stress and liver fibrosis in an animal model of Down Syndrome.

Down Syndrome (DS) is a common genetic disorder characterized by an extra copy of chromosome 21, leading to dysregulation of various metabolic pathways. Oxidative stress in DS is associated with neurodevelopmental defects, neuronal dysfunction, and a dementia onset resembling Alzheimer's disease. Additionally, chronic oxidative stress contributes to cardiovascular diseases and certain cancers prevalent in DS individuals. This study investigates the impact of ageing on oxidative stress and liver fibrosis using a DS murine model (Ts2Cje mice). Our results show that DS mice show increased liver oxidative stress and impaired antioxidant defenses, as evidenced by reduced glutathione levels and increased lipid peroxidation. Therefore, DS liver exhibits an altered inflammatory response and mitochondrial fitness as we showed by assaying the expression of HMOX1, CLPP, and the heat shock proteins Hsp90 and Hsp60. DS liver also displays dysregulated lipid metabolism, indicated by altered expression of PPARα, PPARγ, FATP5, and CTP2. Consistently, these changes might contribute to non-alcoholic fatty liver disease development, a condition characterized by liver fat accumulation. Consistently, histological analysis of DS liver reveals increased fibrosis and steatosis, as showed by Col1a1 increased expression, indicative of potential progression to liver cirrhosis. Therefore, our findings suggest an increased risk of liver pathologies in DS individuals, particularly when combined with the higher prevalence of obesity and metabolic dysfunctions in DS patients. These results shed a light on the liver's role in DS-associated pathologies and suggest potential therapeutic strategies targeting oxidative stress and lipid metabolism to prevent or mitigate liver-related complications in DS individuals.

Investigating the Nootropic Effects of Shilajit on Hyoscine-Induced Zebrafish Model

Objective: This study uses adult zebrafish as a model organism to explore the possible cognitive-boosting properties of shilajit, a traditional Ayurvedic herbal resin. Shilajit is known for its potential cognitive benefits, and the study focuses on its impact on memory and cognitive function. Methods: The study employs a T-maze apparatus to assess cognitive performance in zebrafish, particularly memory, and uses hyoscine, a memory-deficit-inducing compound, in the experiments. Various doses of shilajit (0.1, 0.2, 0.4, 0.8, 1.6 mg/ml) were administered to zebrafish via water immersion, and lipid peroxidation and reduced glutathione were checked to measure oxidative stress. Results: The results reveal that shilajit positively affects memory in zebrafish with hyoscineinduced amnesia. Zebrafish treated with shilajit exhibited improved memory performance, as indicated by increased entries into the reward arm (yellow) (p<0.05) and reduced latency time (p<0.0001). Different doses of shilajit demonstrated varying effects, with higher doses leading to more pronounced memory improvements. Furthermore, the study examined biochemical parameters in the zebrafish brains, with a specific focus on markers of oxidative stress. Shilajit treatment was associated with a decrease in lipid peroxidation and an increase in reduced glutathione levels, signalling a reduction in oxidative stress (p<0.0001). Discussion: Finally, these findings suggest that shilajit not only alleviates memory deficits in the zebrafish model but also possesses potential antioxidative properties in lowering reactive oxygen species (ROS) levels in the brain. Conclusion: Our result suggests that shilajit counteracted the damage caused to cholinergic neurons in zebrafish brains by reducing ROS levels and improving learning and memory.

Cardio-nephrotoxicity mediated by Echis ocellatus venom and its amelioration through kaempferol’s suppressive effect on oxidative stress, inflammation, and apoptosis expression

BackgroundEchis ocellatus venom toxins have the ability to impact multiple organ systems subsequent to envenomation. Kaempferol have been reported to have several therapeutic benefits. In this study, the therapeutic value of kaempferol was investigated in relation to the cardio-nephrotoxicity in rats resulting from E. ocellatus envenoming.MethodsFifty male wistar rats were allotted unbiased into five groups (n = 10) for this study. Group 1 was the control, while rats in groups 2 to 5 were envenomed with LD50 of E. ocellatus venom (0.22 mg/kg bw; i.p.). Group 2 was not treated after envenomation while groups 3, 4 and 5 were treated with polyvalent antivenom, 4 and 8 mg/kg of kaempferol, respectively.ResultsE. ocellatus envenomation caused considerable reduction in organ weight and relative organ weight in the envenomed untreated rats. The venom induced intense oxidative stress, inflammation, apoptotic damage to the cardiac and renal tissues accompanied with severe histomorphology in the organ tissues of untreated envenomed rats. In contrast, kaempferol treatment post-envenomation attenuated the venom-induced cardio-nephrotoxic responses in a dose dependent effect. Kaempferol substantially (p < 0.05) decreased malondialdehyde levels while enhancing reduced glutathione levels and superoxide dismutase and glutathione peroxidase activities in the heart and kidney of envenomed treated rats. Treatment of envenomed rats with kaempferol successfully decreased nitric oxide levels and myeloperoxidase activity. Overexpression of apoptotic caspase 3 and caspase 9 in cardiac and renal tissues were suppressed by kaempferol (p < 0.05). The histopathological result supports kaempferol’s ameliorative ability by convalescing the severe morphological alterations of cardiac and renal tissues induced by the venom.ConclusionFindings elucidate the significance of kaempferol as promising agent in the management of cardio-nephrotoxicity resulting from snakebite envenoming.

Hypermethylation of GSTM5 and its effect on oxidation in myelodysplastic syndrome

AbstractBackgroundHypermethylation of glutathione‐S‐transferase 5 (GSTM5) and its effect on oxidation in the pathogenesis of myelodysplastic syndrome (MDS) were investigated.MethodsGSTM5 methylation was detected in bone marrow (BM) samples from MDS patients, acute myeloid leukemia (AML) patients, and control individuals using methylation‐specific PCR and MassARRAY analysis. Bisulfite sequencing PCR was performed to verify methylation levels, while mRNA levels were determined using reverse transcription polymerase chain reaction. Correlations between GSTM5 methylation and clinical parameters were analyzed. The MDS cell line, SKM‐1, was treated with decitabine, buthionine sulfoximine, or overexpression of GSTM5, and the glutathione level and cell viability were detected.ResultsThe MassARRAY analysis revealed significant differences in GSTM5 methylation levels between the MDS and control groups. GSTM5 methylation levels were significantly increased in the high‐risk subgroup and showed a significant association with MDS progression to AML (hazard ratio = 3.6). Levels of GSTM5 mRNA were significantly decreased in the MDS group, exhibiting a negative correlation with the GSTM5 gene methylation level. Normal BM HS‐5 cells exhibited significantly lower levels of GSTM5 methylation than SKM‐1 cells. Overexpression of GSTM5 in SKM‐1 cells or treatment with buthionine sulfoximine or decitabine resulted in inhibition of proliferation and significantly decreased glutathione levels.ConclusionsGSTM5 plays an anti‐oxidative role in MDS and the tumor suppressor effect of GSTM5 may be mediated by reducing glutathione levels. GSTM5 hypermethylation and low levels of GSTM5 expression may be prognostic markers for MDS.

Empagliflozin Alleviates Carfilzomib-Induced Cardiotoxicity in Mice by Modulating Oxidative Stress, Inflammatory Response, Endoplasmic Reticulum Stress, and Autophagy.

Carfilzomib is an irreversible proteasome inhibitor used for multiple myeloma patients. However, carfilzomib treatment is associated with cardiovascular complications. Empagliflozin, an Sodium Glucose Co-transporter 2 inhibitor (SGLT-2) inhibitor, is an oral antidiabetic drug with proven antioxidant and anti-inflammatory properties. The aim of the present study was to determine the cardioprotective effects of empagliflozin against carfilzomib-induced cardiotoxicity. C57BL/6 mice were randomly divided into four groups: control, empagliflozin, carfilzomib, and carfilzomib + empagliflozin. Empagliflozin prevented carfilzomib-induced cardiotoxicity by ameliorating histological alterations, CK-MB, and troponin-I. Moreover, it inhibited carfilzomib-induced oxidative damage and inflammation via its action on catalase activity, reduced glutathione levels and superoxide dismutase activity, and reduced nuclear factor-κB (p65) and cytokine levels. Mechanistically, empagliflozin abrogated endoplasmic reticulum stress induced by carfilzomib, as evidenced by the effect on the Glucose Regulated Protein-78 (GRP-78)/Activating Transcription Factor 6 (ATF6)/C/EBP homologous protein (CHOP) axis. Intriguingly, carfilzomib significantly induced autophagy, an effect that was further enhanced by empagliflozin, evidenced by increased LC3B and beclin-1 mRNA expression and reduced p62 expression. The effect of empagliflozin on apoptosis was confirmed by reduced expression of active caspase-3. Importantly, empagliflozin did not alter the cytotoxic effect of carfilzomib on human U266B1 multiple myeloma cells. our findings suggest that empagliflozin may provide a new therapeutic strategy to mitigate carfilzomib-induced cardiotoxicity in multiple myeloma patients.

Neuronal glutathione depletion elevates the Aβ42/Aβ40 ratio and tau aggregation in Alzheimer's disease mice.

Alzheimer's disease (AD) involves reduced glutathione levels, causing oxidative stress and contributing to neuronal cell death. Our prior research identified diminished glutamate-cysteine ligase catalytic subunit (GCLC) as linked to cell death. However, the effect of GCLC on AD features such as amyloid and tau pathology remained unclear. To address this, we investigated amyloid pathology and tau pathology in mice by combining neuron-specific conditional GCLC knockout mice with amyloid precursor protein (App) knockin (KI) or microtubule-associated protein tau (MAPT) KI mice. Intriguingly, GCLC knockout resulted in an increased Aβ42/40 ratio. Additionally, GCLC deficiency in MAPT KI mice accelerated the oligomerization of tau through intermolecular disulfide bonds. These findings suggest that the decline in glutathione levels, due to aging or AD pathology, may contribute to the progression of AD.

Paclitaxel Overload Supramolecular Oxidative Stress Nanoamplifier with a CDK12 Inhibitor for Enhanced Cancer Therapy.

Combination therapy has emerged as a promising approach for treating tumors, although there is room for improvement. This study introduced a novel strategy that combined the enhancement of apoptosis, ferroptosis, and DNA damage to improve therapeutic outcomes for prostate cancer. Specifically, we have developed a supramolecular oxidative stress nanoamplifier, which was comprised of β-cyclodextrin, paclitaxel, and ferrocene-poly(ethylene glycol). Paclitaxel within the system disrupted microtubule dynamics, inducing G2/M phase arrest and apoptosis. Concurrently, ferrocene utilized hydrogen peroxide to generate toxic hydroxyl radicals in cells through the Fenton reaction, triggering a cascade of reactive oxygen species expansion, reduction of glutathione levels, lipid peroxidation, and ferroptosis. The increased number of hydroxyl radicals and the inhibitory effect of THZ531 on DNA repair mechanisms exacerbated DNA damage within tumor cells. As expected, the supramolecular nanoparticles demonstrated excellent drug delivery ability to tumor cells or tissues, exhibited favorable biological safety in vivo, and enhanced the killing effect on prostate cancer.

Soot nanoparticles promote ferroptosis in dopaminergic neurons via alteration of m6A RNA methylation in Parkinson’s disease

Soot nanoparticles (SNPs) are black carbon prevalent in atmospheric environment with significant impacts on public health, leading to neurodegenerative diseases including development of Parkinson’s disease (PD). This study investigated the effects of SNPs exposure on PD symptoms, employing both in vivo and in vitro PD models. In the in vivo experiments, animal behavior assessments showed that SNPs exposure exacerbated motor and cognitive impairments in PD mice. Molecular biology techniques further unveiled that SNPs aggravated degeneration of dopaminergic neurons. In vitro experiments revealed that SNPs exposure intensified ferroptosis of PD cells by increasing reactive oxygen species and iron ion levels, while reducing glutathione levels and mitochondrial membrane potential. Sequencing tests indicated elevated N6-methyladenosine (m6A) alteration of the ferroptosis-related protein, acyl-CoA synthetase long chain family member 4 (ACSL4). This study demonstrates that SNPs may exacerbate the onset and progression of PD by recruiting YTH domain-containing family protein 1 (YTHDF1) protein, enhancing m6A methylation in the ACSL4 5′UTR, amplifying ACSL4 protein expression, and accelerating the ferroptosis process in dopaminergic neurons. These molecular mechanisms underlying SNPs exacerbation of PD development may provide crucial insights for formulating environmental safety regulations and potential therapeutic strategies addressing PD in populations residing in regions with varied air quality.

Increase in ascorbate content in leaves of Hordeum vulgare after spraying with cold atmospheric plasma-treated water in combination with waterlogging and re-aeration

Flood events are likely to increase in the near future and are one of the events most threatening to agricultural production. Barley is the fourth most important crop and the cereal most sensitive to excessive moisture stress. Improving the stress tolerance of crops to a variety of stress factors caused by a more volatile climate is an important task for the coming years. The aim of this study was to investigate the efficacy of cold atmospheric plasma-treated water (PTW) as a foliar spray to stimulate the antioxidant system of Hordeum vulgare and thereby improve plant stress tolerance. For this purpose, we analysed the components of the ascorbate-glutathione cycle in barley leaves and roots without stress and under waterlogging conditions. PTW increased the content of total and reduced ascorbate in leaves as well as the content of reduced ascorbate in roots four weeks after treatment. This was observed both, under stress free conditions and after waterlogging and re-aeration. In leaves, enzyme activities also increased after re-aeration, and in roots, total and reduced glutathione levels increased after waterlogging compared to the control. The accumulation of low molecular weight antioxidants may increase tolerance to a variety of stress factors through more efficient scavenging of ROS. Overall, treatment of plants with PTW may trigger an adaptive response that leads to mitigation of the negative effects of stress, and thus, could be used as a priming agent for protection against subsequent more severe stress factors that occur in the plants' natural environment.

Levels of melatonin and some indicators of angiogenesis, antioxidant system and lipid peroxidation in blood plasma in women with uterine leiomyoma

Uterine leiomyoma is one of the most common gynaecological diseases, which often leads to loss of fertility. It is known that in this pathology, damage to the tissues of the uterus is accompanied by oxidative stress, and the mechanisms of its compensation play a decisive role in the process of myometrial regeneration, especially when performing organ-preserving operations. The aim of the study was to determine the levels of melatonin, reproductive hormones and state of angiogenesis, antioxidant system and lipid peroxidation in women of reproductive age who were diagnosed with uterine leiomyoma. Material and methods. 60 women of reproductive age with uterine leiomyoma (study group) were examined. The control group consisted of 20 healthy women of the same age group. Melatonin levels in women's blood were determined once, on an empty stomach, at 8 a.m.; the concentrations of estradiol and progesterone in the follicular phase of the menstrual cycle were also measured. The state of the angiogenesis system was studied by examining the levels of vascular endothelial growth factor (VEGF) and the content of the final metabolites of nitric oxide NO in blood plasma. The activity of the antioxidant system was assessed by blood plasma concentrations of reduced glutathione, glutathione peroxidase, and glutathione transferase. Indicators of lipid peroxidation were investigated by the content of malondialdehyde (MDA) in blood plasma and erythrocytes. Results. It was found that in the patients of the study group with leiomyoma, there was a significantly lower level of melatonin in blood plasma (111.1 ± 18.5 ng/mL) compared to the control group (153.5 ± 8.5 ng/mL), while the concentration of estradiol was almost three times higher (107.4 ± 25.3 pg/mL) compared to the control group (36.2 ± 3.2 pg/mL), and the concentration of progesterone was 1.9 times higher (2.1 ± 0.4 ng/mL compared to 1.1 ± 0.5 ng/mL in the control group). The level of VEGF in blood plasma in women with uterine leiomyoma was also higher (90.4 ± 23.6 pg/mL) compared to the control group (35.1 ± 8.3 pg/mL), as well as the concentration of final metabolites of nitric oxide, which reached 25.3 ± 5.9 pg/mL compared to 9.9 ± 3.9 pg/mL in the control group. The reduced glutathione level in the blood plasma of women with uterine leiomyoma was significantly lower (0.77 ± 0.13 µmol/L) compared to healthy women (1.02 ± 0.14 µmol/L) in the control group, while the concentrations of glutathione-S-transferase and glutathione peroxidase enzymes were higher (161.3 ± 22.3 ng/mL and 235.7 ± 35.9 ng/mL, respectively), whereas in the control group these indicators were 118.9 ± 18.0 ng/mL and 105.3 ± 41.2 ng/mL, respectively. The MDA content in women of the study group was higher, measuring 5.2 ± 0.8 nmol/L in plasma and 10.8 ± 1.1 nmol/L in erythrocytes compared to 2.3 ± 0.8 nmol/L and 5.3 ± 0.8 nmol/L in the control group, respectively. Conclusions. The levels of melatonin and reduced glutathione in the blood plasma of women with uterine leiomyoma were significantly lower, while the concentrations of estradiol, progesterone, glutathione-S-transferase, glutathione peroxidase, VEGF, final metabolites of nitric oxide, as well as the average MDA content in plasma and erythrocytes, were significantly higher compared to healthy women. In the study group, the relationship between the level of progesterone in blood plasma and the content of malondialdehyde in erythrocytes was described using a linear regression equation, which, as we suggest, indicates an activating effect of progesterone on oxidative stress mechanisms in the myometrium. In our opinion, oxidative stress in uterine leiomyoma occurs due to inadequate activity of the antioxidant system, an integral part of which is melatonin, leading to enhanced angiogenesis against the background of estrogen-induced myometrial proliferation.

Identification of early events in nitrogen mustard pulmonary toxicity that are independent of infiltrating inflammatory cells using precision cut lung slices

Nitrogen mustard (NM; mechlorethamine) is a cytotoxic vesicant known to cause acute lung injury which can progress to chronic disease. Due to the complex nature of NM injury, it has been difficult to analyze early responses of resident lung cells that initiate inflammation and disease progression. To investigate this, we developed a model of acute NM toxicity using murine precision cut lung slices (PCLS), which contain all resident lung cell populations. PCLS were exposed to NM (1–100 μM) for 0.5–3 h and analyzed 1 and 3 d later. NM caused a dose-dependent increase in cytotoxicity and a reduction in metabolic activity, as measured by LDH release and WST-1 activity, respectively. Optimal responses were observed with 50 μM NM after 1 h incubation and these conditions were used in further experiments. Analysis of PCLS bioenergetics using an Agilent Seahorse showed that NM impaired both glycolytic activity and mitochondrial respiration. This was associated with injury to the bronchial epithelium and a reduction in methacholine-induced airway contraction. NM was also found to cause DNA damage in bronchial epithelial cells in PCLS, as measured by expression of γ-H2AX, and to induce oxidative stress, which was evident by a reduction in glutathione levels and upregulation of the antioxidant enzyme catalase. Cleaved caspase-3 was also upregulated in airway smooth muscle cells indicating apoptotic cell death. Characterizing early events in NM toxicity is key in identifying therapeutic targets for the development of efficacious countermeasures.

Cardioprotective Effect of Eugenol Against Cd-Induced Inflammation, Oxidative Stress, and Dyslipidemia in Male Rats: An In Vivo and Molecular Docking Study.

Cadmium, a highly toxic heavy metal, can cause severe damage to several vital organs including the kidney, liver, and brain. Many of the natural compounds found in aromatic plants have beneficial pharmacological properties. Eugenol is one such compound reported to have anti-inflammatory and antioxidant properties. The aim of this study is to investigate whether eugenol, a natural compound found in aromatic plants known for its anti-inflammatory and antioxidant properties, can mitigate the detrimental effects of cadmium exposure on cardiac inflammation, oxidative stress, and dyslipidemia. Male albino rats were subjected to randomization into four groups, each comprising six animals, to investigate the potential of eugenol in mitigating cadmium-induced toxicity. All groups received oral gavage treatment for 21days. Following the treatment regimen, cardiac tissue specimens were collected for analysis. The assessment of cardiac antioxidant status entailed the determination of enzymatic activities including catalase, SOD, GST, and GPx. Additionally, levels of lipid peroxidation, reduced glutathione, protein carbonyl oxidation, and thiol levels were quantified in the cardiac tissue samples. To evaluate cardiac damage, marker enzymes such as LDH and CK-MB were measured. Furthermore, the inflammatory response in the cardiac tissue induced by cadmium exposure was assessed through the quantification of NO, TNF-α, and IL-6 levels. Additionally, molecular docking and dynamics studies were conducted utilizing autodock and GLIDE methodologies. Cadmium administration markedly enhanced the activities of LDH and CK-MB, prominent cardiac markers. Furthermore, cadmium treatment also demonstrated a significant decrease in the reduced glutathione levels and antioxidant enzyme activities. Significant elevation of the inflammatory markers was also observed in the cadmium-treated group. Eugenol treatment effectively ameliorates cadmium-induced biochemical changes. This study underscores the potent anti-inflammatory and antioxidant attributes of eugenol. Co-administration of eugenol alongside cadmium exhibited remarkable protective efficacy against cadmium-induced cardio-toxicity. Eugenol demonstrated the capability to reinstate the cellular redox equilibrium of rats subjected to cadmium treatment to levels akin to those of the normal control group.

Lipid Peroxidation, Reduced Glutathione, and Glutathione Peroxidase Levels in Intervertebral Discs of Patients with Lumbar Degenerative Disc Disease.

BACKGROUND Either a reduction in antioxidant levels or an accumulation of reactive oxygen species can heighten susceptibility to oxidative damage in disc cells. To date, no research has investigated the levels of lipid peroxidation products (thiobarbituric acid reactive substances [TBARs]), reduced glutathione (GSH), and glutathione peroxidase (GPx) in excised human lumbar disc tissues affected by degenerative disease. Therefore, this study aimed to evaluate lipid peroxidation products in excised disc tissues from patients with degenerative disc disease. MATERIAL AND METHODS Forty-two patients were enrolled. Patients were divided into lumbar disc degeneration (LDD) and nonlumbar disc degeneration (nonLDD) groups according to Pfirrmann classification. Intervertebral discs were obtained from all patients during the operation and were homogenized for analysis. TBARs levels were measured using fluorometry. GSH levels and GPx activity were quantified spectrophotometrically using a kinetic method. RESULTS TBARs levels in excised discs from LDD patients (5.18±4.14) were significantly higher than those from nonLDD patients (2.56±1.23, P=0.008). The levels of TBARs tended to increase with the severity of degeneration according to the Pfirrmann classification. However, these 2 groups showed no significant differences in reduced glutathione levels or glutathione peroxidase activity (P>0.05). Patients with LDD exhibited a worse health-related quality of life, reflected in lower utility and EQ-VAS scores and higher Oswestry disability index scores. CONCLUSIONS There was a notable increase in lipid peroxidation products in the excised intervertebral discs of patients with LDD. This finding suggests that oxidative stress may contribute to the development of disc degeneration.

Feasibility study of multimodal imaging for redox status and glucose metabolism in tumor

Understanding the tumor redox status is important for efficient cancer treatment. Here, we noninvasively detected changes in the redox environment of tumors before and after cancer treatment in the same individuals using a novel compact and portable electron paramagnetic resonance imaging (EPRI) device and compared the results with glycolytic information obtained through autoradiography using 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG). Human colon cancer HCT116 xenografts were used in the mice. We used 3-carbamoyl-PROXYL (3CP) as a paramagnetic and redox status probe for the EPRI of tumors. The first EPRI was followed by the intraperitoneal administration of buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis, or X-ray irradiation of the tumor. A second EPRI was performed on the following day. Autoradiography was performed after the second EPRI. After imaging, the tumor sections were evaluated by histological analysis and the amount of reducing substances in the tumor was measured. BSO treatment and X-ray irradiation significantly decreased the rate of 3CP reduction in tumors. Redox maps of tumors obtained from EPRI can be compared with tissue sections of approximately the same cross section. BSO treatment reduced glutathione levels in tumors, whereas X-ray irradiation did not alter the levels of any of the reducing substances. Comparison of the redox map with the autoradiography of [18F]FDG revealed that regions with high reducing power in the tumor were active in glucose metabolism; however, this correlation disappeared after X-ray irradiation. These results suggest that the novel compact and portable EPRI device is suitable for multimodal imaging, which can be used to study tumor redox status and therapeutic efficacy in cancer, and for combined analysis with other imaging modalities.

Leucaena leucocephala succinate based polyelectrolyte complexes for colon delivery of synbiotic in management of inflammatory bowel disease

Polyelectrolyte complexes (PECs) formed by the interaction between oppositely charged polymers have emerged as promising carriers for accomplishing colon-specific release. In this study, we have explored the potential of polyelectrolyte complexes between a succinate derivative of Leucaena leucocephala galactomannan and cationic guar gum for colon delivery of synbiotic. The PECs were prepared using a polyelectrolyte complexation method and characterized. The PECs exhibited excellent stability, with high encapsulation efficiency for both probiotics (95.53 %) and prebiotics (83.33 %). In vitro studies demonstrated enhanced survivability and proliferation of the encapsulated probiotics in the presence of prebiotics (93.29 %). The SEM images revealed a smooth and firm structure with reduced number of pores when both prebiotic and probiotic were encapsulated together. The treatment with synbiotic PECs in acetic acid induced IBD rats significantly relieves colitis symptoms as was evident from colon/body ratio, DAI score and histopathology studies. An increase in the protein and reduced glutathione levels and reduction in superoxide dismutase activity was observed in colitic rats that received synbiotic treatment as compared to colitic rats. Overall, this study highlights the potential of Leucaena leucocephala succinate-cationic guar gum PECs as a promising system for colon-specific synbiotic delivery, with implications for improved gut health and the treatment of various gastrointestinal disorders.

Hepatoprotective effect of jojoba oil against lead-induced toxicity in rats

Background Previous investigations showed that jojoba oil exhibited a protective effect against hepatotoxicity caused by different toxicants, however, to the best of our knowledge, no prior research has been done to determine the effectiveness of jojoba oil in protecting against lead toxicity. Objective This study assessed the hepatoprotective properties of jojoba oil against lead toxicity in rats. Materials and methods The study included four groups, each consisting of six Sprague Dawley male rats, and orally administered jojoba oil (JO group), lead acetate (LA group), and lead acetate plus jojoba oil (protective group) Results and conclusion The results showed that lead acetate-induced hepatotoxic effects were revealed by increased serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activities with hepatic histomorphological changes. There was a significant increase in serum total cholesterol, triglycerides, and low-density lipoprotein-cholesterol, while levels of high-density lipoprotein-cholesterol significantly declined compared to normal rats. Additionally, lead acetate triggered oxidative damage of hepatocytes, evidenced by a significant increase of malondialdehyde levels and a decrease of reduced glutathione levels and activities of superoxide dismutase and glutathione S-transferase. Administration of lead was associated with a change in the distribution of cells over different cell cycle phases, characterized by a marked increase in the sub G1 cell population and a significant decrease in the G0/G1 cell population. Supplementation of jojoba oil with lead acetate relieved the toxic impacts of lead acetate with an enhancement of the liver enzyme activities, antioxidant status, lipid profile parameters, and histopathological alterations. In conclusion, jojoba oil might be an effective natural product that offers a promising preventive action towards lead-induced liver damage in rats.

Abstract 5962: Novel xCT-targeted biologics significantly suppress metastasis, improve survival, and sensitize primary tumors to chemotherapy in TNBC xenograft models

Abstract Background: Triple negative breast cancer (TNBC) is a highly heterogeneous subset of breast cancer, which has the worst prognosis and lacks specifically targeted therapeutic options. The TNBC subtype termed M/MSL is enriched with cells of high mesenchymal state and increased stemness, and is particularly resistant to current therapies1,2. But this cancer cell phenotype is susceptible to ferroptosis, hence targeting these aggressive tumors with ferroptosis inducers such as xCT inhibitors (xCTi) is an attractive alternative. The cystine/glutamate exchanger xCT/SLC7A11 plays a key role in maintaining redox homeostasis in cancer cells. xCT is expressed on subsets of most solid tumors, including stem/progenitor and metastatic tumor cells. xCT inhibition yields a variety of anti-proliferative phenotypes including death by ferroptosis3. xCT knockout mice exhibit normal development and lifespan. Altogether, targeting xCT outside of CNS may potentially have widespread clinical utility in cancer treatment. Results: We present preclinical data demonstrating development of novel, first-in-class xCT-targeted biotherapeutics (AX68c, AX76c) using studies in TNBC cell lines in vitro and in xenograft. We find that these agents have highly favorable pharmacokinetics, with FcRn-dependent serum half-lives greatly exceeding those of known small molecule xCTi. In vitro, AX68c or AX76c reduces glutathione levels in TNBC cells in accord with inhibition of xCT function. Analysis of anti-proliferative effects in a panel of TNBC cell lines revealed particular potency against those of M/MSL phenotype (IC50s 0.3-1uM). We further tested the susceptibility of the mesenchymal phenotype to AX68c and found that EMT induction in epithelial cancer cells significantly increased sensitivity in a ferroptosis-dependent manner. In wildtype and immunodeficient mice, AX68c is well tolerated at steady-state serum concentrations that are 15-300 fold of its in vitro IC50s in tested TNBC cells. In orthotopic MDA-MB-231 xenografts, AX68c treatment significantly reduced tumor metastasis and sensitized primary tumors to cisplatin and paclitaxel. Bulk RNAseq and GSEA analysis on primary tumors revealed treatment associated alterations in key cancer signaling pathways such as TGFβ, INFγ and TNFα/NFκB. In MDA-MB-436 orthotopic xenografts, AX68c alone led to significantly improved survival primarily through abrogating metastasis. Combining AX68c and cisplatin further prolonged survival through concurrent suppression of metastasis and primary tumor growth. Conclusions: We conclude that our anti-xCT biologics may provide novel targeted therapies for M/MSL-subtype TNBC and metastatic tumors with a large mesenchymal component. 1. Viswanathan, et al., Nature, 2017; 2. Wang, et al., npj Precision Oncology, 2021; 3. Koppula, et al., Protein and Cell, 2021 (review). Citation Format: He Gong, Jun Li, Cyrus Becker, Luika Timmerman, Shaheen Sikandar, Yong Huang. Novel xCT-targeted biologics significantly suppress metastasis, improve survival, and sensitize primary tumors to chemotherapy in TNBC xenograft models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5962.

Abstract 384: SLC7A11 modulates sensitivity to the first-in-class mitochondrial peroxiredoxin 3 inhibitor thiostrepton (RSO-021) via a ferroptosis independent pathway

Abstract Mitochondrial peroxiredoxin 3 (PRX3) has been identified as an actionable cancer vulnerability that is currently being investigated in the first-in-human phase 1 clinical trial, MITOPE (NCT05278975). RSO-021 (thiostrepton or TS) is a redox-active drug that inhibits PRX3’s peroxidase activity via covalent adduction of its active site peroxidatic and resolving cysteine residues, forming an irreversible crosslink across the protein dimer. Covalent inhibition of PRX3 results in tumor cell death due to a diminished ability to remove high levels of mitochondrial reactive oxygen species (ROS) in cancer cells. To better understand the mechanism underpinning sensitivity and resistance, TS-tolerant human mesothelioma cell lines were generated under constant TS pressure and subjected to a drug-screen comprising chemotherapeutic agents, metabolic inhibitors, ROS modulating agents and ferroptosis-inducing compounds, to identify synergistic interactions compared with TS- sensitive cell lines. Erastin, an SLC7A11 inhibitor exhibited the greatest synergy when combined with TS, potentiated PRX3 covalent crosslinking and cellular ROS levels. Synergy with TS was enhanced by cystine depletion and could be phenocopied by siRNA knockdown of SLC7A11. SLC7A11 was up-regulated in TS-tolerant cells and resistance could be overcome with erastin. TS-tolerant cell lines have significantly reduced glutathione levels and slowed proliferation. Ferroptosis inhibitors ferrostatin-1 and liproxstatin-1 did not inhibit TS or TS in combination with erastin. In summary, SLC7A11 up-regulation confers tolerance to TS through a mechanism involving a cysteine-dependent modulation of the redox state independent of canonical ferroptosis, that can be overcome by the addition of an SLC7A11 inhibitor. The correlation between SLC7A11 with response to TS in a 33-patient primary mesothelioma explant co-clinical trial, and patients enrolled into the MITOPE phase 1/2 trial will be presented. Citation Format: Terri Messier, Victoria Gibson, Aleksandra Bzura, Joanna Dzialo, Charlotte Poile, Stephanie Stead, Alexis Saaman, George N. Naumov, Dean A. Fennell, Brian Cunniff. SLC7A11 modulates sensitivity to the first-in-class mitochondrial peroxiredoxin 3 inhibitor thiostrepton (RSO-021) via a ferroptosis independent pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 384.

Disturbances in mitochondrial bioenergetics and control quality and unbalanced redox homeostasis in the liver of a mouse model of mucopolysaccharidosis type II.

Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is a lysosomal storage disease caused by mutations in the gene encoding the enzyme iduronate 2-sulfatase (IDS) and biochemically characterized by the accumulation of glycosaminoglycans (GAGs) in different tissues. It is a multisystemic disorder that presents liver abnormalities, the pathophysiology of which is not yet established. In the present study, we evaluated bioenergetics, redox homeostasis, and mitochondrial dynamics in the liver of 6-month-old MPS II mice (IDS-). Our findings show a decrease in the activity of α-ketoglutarate dehydrogenase and an increase in the activities of succinate dehydrogenase and malate dehydrogenase. The activity of mitochondrial complex I was also increased whereas the other complex activities were not affected. In contrast, mitochondrial respiration, membrane potential, ATP production, and calcium retention capacity were not altered. Furthermore, malondialdehyde levels and 2',7'-dichlorofluorescein oxidation were increased in the liver of MPS II mice, indicating lipid peroxidation and increased ROS levels, respectively. Sulfhydryl and reduced glutathione levels, as well as glutathione S-transferase, glutathione peroxidase (GPx), superoxide dismutase, and catalase activities were also increased. Finally, the levels of proteins involved in mitochondrial mass and dynamics were decreased in knockout mice liver. Taken together, these data suggest that alterations in energy metabolism, redox homeostasis, and mitochondrial dynamics can be involved in the pathophysiology of liver abnormalities observed in MPS II.