Redox Biology最新文献

{"title":"Branched-chain amino acids alleviate NAFLD via inhibiting de novo lipogenesis and activating fatty acid β-oxidation in laying hens","authors":"Huafeng Jian ,&nbsp;Ru Li ,&nbsp;Xuan Huang ,&nbsp;Jiankui Li ,&nbsp;Yan Li ,&nbsp;Jiangang Ma ,&nbsp;Mingkun Zhu ,&nbsp;Xinyang Dong ,&nbsp;Hua Yang ,&nbsp;Xiaoting Zou","doi":"10.1016/j.redox.2024.103385","DOIUrl":"10.1016/j.redox.2024.103385","url":null,"abstract":"<div><div>The adverse metabolic impacts of branched-chain amino acids (BCAA) have been elucidated are mediated by isoleucine and valine. Dietary restriction of isoleucine promotes metabolic health and increases lifespan. However, a high protein diet enriched in BCAA is presently the most useful therapeutic strategy for nonalcoholic fatty liver disease (NAFLD), yet, its underlying mechanism remains largely unknown. Fatty liver hemorrhagic syndrome (FLHS), a specialized laying hen NAFLD model, can spontaneously develop fatty liver and hepatic steatosis under a high-energy and high-protein dietary background that the pathogenesis of FLHS is similar to human NAFLD. The mechanism underlying dietary BCAA control of NAFLD development in laying hens remains unclear. Herein, we demonstrate that dietary supplementation with 67 % High BCAA has unique mitigative impacts on NAFLD in laying hens. A High BCAA diet alleviates NAFLD, by inhibiting the tryptophan-ILA-AHR axis and MAPK9-mediated <em>de novo</em> lipogenesis (DNL), promoting ketogenesis and energy metabolism, and activating PPAR-RXR and pexophagy to promote fatty acid β-oxidation. Furthermore, we uncover that High BCAA strongly activates ubiquitin-proteasome autophagy via downregulating UFMylation to trigger MAPK9-mediated DNL, fatty acid elongation and lipid droplet formation-related proteins ubiquitination degradation, activating PPAR-RXR and pexophagy mediated fatty acid β-oxidation and lipolysis. Together, our data highlight moderating intake of high BCAA by inhibiting the AHR/MAPK9 are promising new strategies in NAFLD and FLHS treatment.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"77 ","pages":"Article 103385"},"PeriodicalIF":10.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142473470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduced microRNA-744 expression in mast cell-derived exosomes triggers epithelial cell ferroptosis in acute respiratory distress syndrome","authors":"Xiaobin Fang ,&nbsp;Fei Gao ,&nbsp;Ling Zheng ,&nbsp;Fu-Shan Xue ,&nbsp;Tao Zhu ,&nbsp;Xiaochun Zheng","doi":"10.1016/j.redox.2024.103387","DOIUrl":"10.1016/j.redox.2024.103387","url":null,"abstract":"<div><div>Acute respiratory distress syndrome (ARDS) is a critical disorder characterized by immune-related damage to epithelial cells; however, its underlying mechanism remains elusive. This study investigated the effects of alterations in microRNA (miRNA) expression in mast cell-derived exosomes on human bronchial epithelial (HBE) cells and ARDS development in cellular and mouse models challenged with lipopolysaccharide. Lipopolysaccharide-treated mast cell-derived exosomes reduced glutathione peroxidase 4 (<em>GPX4</em>) expression and increased long-chain acyl-CoA synthetase 4 (<em>ACSL4</em>), 15-lipoxygenase (<em>ALOX15</em>), and inflammatory mediator levels in HBE cells. miRNA sequencing revealed a reduction in mast cell-derived exosomal miR-744 levels, which was associated with the regulation of ACSL4, ALOX15, and GPX4 expression. This downregulation of exosomal miR-744 expression reduced miR-744 levels and promoted ferroptosis in HBE cells, whereas the experimental upregulation of miR-744 reversed these adverse effects. Down-regulation of miR-744 induced the expression of markers for ferroptosis and inflammation in HBE cells and promoted pulmonary ferroptosis, inflammation, and injury in LPS-stimulated mice. <em>In vivo</em>, treatment with <em>ACSL4</em>, <em>ALOX15</em>, and <em>GPX4</em> inhibitors mitigated these effects, and experimental miR-744 expression rescued the lipopolysaccharide-induced changes in HBE cells and mouse lungs. Notably, miR-744 levels were reduced in the plasma and exosomes of patients with ARDS. We concluded that decreased mast cell-derived exosomal miR-744 levels trigger epithelial cell ferroptosis, promoting lung inflammation and damage in ARDS. This study provides new mechanistic insights into the development and sustained pulmonary damage associated with ARDS and highlights potential therapeutic strategies.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"77 ","pages":"Article 103387"},"PeriodicalIF":10.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142392860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chronic alcohol consumption aggravates acute kidney injury through integrin β1/JNK signaling","authors":"Zhanji Zhan ,&nbsp;Jiongcheng Chen ,&nbsp;Hong Zhou ,&nbsp;Xue Hong ,&nbsp;Li Li ,&nbsp;Xianhui Qin ,&nbsp;Haiyan Fu ,&nbsp;Youhua Liu","doi":"10.1016/j.redox.2024.103386","DOIUrl":"10.1016/j.redox.2024.103386","url":null,"abstract":"<div><div>Alcohol abuse is one of the major public health problems in the world and is associated with various health conditions. However, little is known about the effect of alcohol consumption on acute kidney injury (AKI). In this study, we demonstrate that chronic and binge alcohol feeding with a Lieber-DeCarli diet containing 5 % ethanol for 10 days, followed by a single dose of 31.5 % ethanol by gavage, aggravated AKI after ischemia-reperfusion injury (IRI) in female, but not in male, mice. Kidney dysfunction, histopathology and tubular cell apoptosis were more severe in EtOH-fed female mice after IRI, compared to pair-fed controls. RNA sequencing and experimental validation uncovered that activation of integrin β1 and its downstream c-Jun NH2-terminal kinase (JNK) aggravated AKI in EtOH-fed mice. Knockdown of integrin β1 inhibited JNK phosphorylation and alleviated AKI in EtOH-fed mice, whereas activation of integrin β1 by agonist antibody increased JNK phosphorylation, worsened renal histological injury and tubular cell apoptosis, and aggravated kidney dysfunction. In vitro, activation of integrin β1 increased JNK phosphorylation and induced tubular epithelial cell apoptosis. The detrimental effect of EtOH feeding was primarily mediated by acetaldehyde, as its levels were increased in the blood, liver and kidney of female mice fed with ethanol. Acetaldehyde per se activated integrin β1/JNK signaling and induced tubular cell apoptosis <em>in vitro</em>. These findings suggest that alcohol consumption increases vulnerability to AKI in female mice, which is probably mediated by acetaldehyde/integrin β1/JNK signaling cascade.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"77 ","pages":"Article 103386"},"PeriodicalIF":10.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142392857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A quantitative proteomic approach to evaluate the efficacy of carnosine in a murine model of chronic obstructive pulmonary disease (COPD)","authors":"Alfonsina D’Amato ,&nbsp;Alessandra Altomare ,&nbsp;Ettore Gilardoni ,&nbsp;Giovanna Baron ,&nbsp;Marina Carini ,&nbsp;Elsa Melloni ,&nbsp;Gloria Padoani ,&nbsp;Silvia Vailati ,&nbsp;Giovanni Caponetti ,&nbsp;Giancarlo Aldini","doi":"10.1016/j.redox.2024.103374","DOIUrl":"10.1016/j.redox.2024.103374","url":null,"abstract":"<div><div>The aim of the work was to study a dose-dependent effect of inhaled carnosine (10, 50 or 100 mg/kg/day) in mice exposed to cigarette smoke as a model of chronic obstructive pulmonary disease (COPD). A dose-dependent loading of the dipeptide in lung tissue and bronchoalveolar lavage (BAL) was firstly demonstrated by LC-ESI-MS analysis. Cigarette smoke exposure induced a significant lung inflammation and oxidative stress in mice which was dose-dependently reduced by carnosine. Inflammation was firstly evaluated by measuring the cytokines content in the BAL. All the measured cytokines were found significantly higher in the smoke group in respect to control, although the data are affected by a significant variability. Carnosine was found effective only at the highest dose tested and significantly only for keratinocyte-derived cytokine (KC). Due to the high variability of cytokines, a quantitative proteomic approach to better understand the functional effect of carnosine and its molecular mechanisms was used. Proteomic data clearly indicate that smoke exposure had a great impact on lung tissue with 692 proteins differentially expressed above a threshold of 1.5-fold. Protein network analysis identified the activation of some pathways characteristic of COPD, including inflammatory response, fibrosis, induction of immune system by infiltration and migration of leukocyte pathways, altered pathway of calcium metabolism and oxidative stress. Carnosine at the tested dose of 100 mg/kg was found effective in reverting all the pathways evoked by smoke. Only a partial reverse of the dysregulated proteins was evident at low- and mid-tested doses, although, for some specific proteins, indicating an overall dose-dependent effect. Regarding the molecular mechanisms involved, we found that carnosine upregulated some key enzymes related to Nrf2 activation and in particular glutathione peroxidase, reductase, transferase, SOD, thioredoxins, and carbonyl reductase. Such mechanism would explain the antioxidant and anti-inflammatory effects of the dipeptide.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"77 ","pages":"Article 103374"},"PeriodicalIF":10.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142406724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanism of action and impact of thiol homeostasis on efficacy of an enzyme replacement therapy for classical homocystinuria","authors":"Thilo Magnus Philipp ,&nbsp;Teodoro Bottiglieri ,&nbsp;Wilmelenne Clapper ,&nbsp;Kai Liu ,&nbsp;Steve Rodems ,&nbsp;Csaba Szabo ,&nbsp;Tomas Majtan","doi":"10.1016/j.redox.2024.103383","DOIUrl":"10.1016/j.redox.2024.103383","url":null,"abstract":"<div><div>Homocystinuria (HCU) due to cystathionine beta-synthase (CBS) deficiency is characterized by elevated plasma and tissue homocysteine levels. There is no cure, but HCU is typically managed by methionine/protein restriction and vitamin B₆ supplementation. Enzyme replacement therapy (ERT) based on human CBS has been developed and has shown significant efficacy correcting HCU phenotype in several mouse models by bringing plasma total homocysteine below the clinically relevant 100 μM threshold. As the reactive nature of homocysteine promotes disulfide formation and protein binding, and ERT is unable to normalize plasma total homocysteine levels, the mechanism of action of ERT in HCU remains to be further characterized. Here we showed that only a reduced homocysteine serves as a substrate for CBS and its availability restricts the homocysteine-degrading capacity of CBS. We also demonstrated that cells export homocysteine in its reduced form, which is efficiently metabolized by CBS in the culture medium. Availability of serine, a CBS co-substrate, was not a limiting factor in our cell-based model. Biological reductants, such as N-acetylcysteine, MESNA or cysteamine, increased the availability of the reduced homocysteine and thus promoted its subsequent CBS-based elimination. In a transgenic I278T mouse model of HCU, administration of biological reductants significantly increased the proportion of protein-unbound homocysteine in plasma, which improved the efficacy of the co-administered CBS-based ERT, as evidenced by significantly lower plasma total homocysteine levels. These results clarify the mechanism of action of CBS-based ERT and unveil novel pharmacological approaches to further increase its efficacy.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"77 ","pages":"Article 103383"},"PeriodicalIF":10.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142375887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A randomized trial of pharmacological ascorbate, gemcitabine, and nab-paclitaxel for metastatic pancreatic cancer","authors":"Kellie L. Bodeker ,&nbsp;Brian J. Smith ,&nbsp;Daniel J. Berg ,&nbsp;Chandrikha Chandrasekharan ,&nbsp;Saima Sharif ,&nbsp;Naomi Fei ,&nbsp;Sandy Vollstedt ,&nbsp;Heather Brown ,&nbsp;Meghan Chandler ,&nbsp;Amanda Lorack ,&nbsp;Stacy McMichael ,&nbsp;Jared Wulfekuhle ,&nbsp;Brett A. Wagner ,&nbsp;Garry R. Buettner ,&nbsp;Bryan G. Allen ,&nbsp;Joseph M. Caster ,&nbsp;Barbara Dion ,&nbsp;Mandana Kamgar ,&nbsp;John M. Buatti ,&nbsp;Joseph J. Cullen","doi":"10.1016/j.redox.2024.103375","DOIUrl":"10.1016/j.redox.2024.103375","url":null,"abstract":"<div><h3>Background</h3><div>Patients with metastatic pancreatic ductal adenocarcinoma (PDAC) have poor 5-year survival. Pharmacological ascorbate (P-AscH^-, high dose, intravenous, vitamin C) has shown promise as an adjunct to chemotherapy. We hypothesized adding P-AscH^- to gemcitabine and <em>nab</em>-paclitaxel would increase survival in patients with metastatic PDAC.</div></div><div><h3>Methods</h3><div>Patients diagnosed with stage IV pancreatic cancer randomized 1:1 to gemcitabine and <em>nab</em>-paclitaxel only (SOC, control) or to SOC with concomitant P-AscH⁻, 75 g three times weekly (ASC, investigational). The primary outcome was overall survival with secondary objectives of determining progression-free survival and adverse event incidence. Quality of life and patient reported outcomes for common oncologic symptoms were captured as an exploratory objective. Thirty-six participants were randomized; of this 34 received their assigned study treatment. All analyses were based on data frozen on December 11, 2023.</div></div><div><h3>Results</h3><div>Intravenous P-AscH^- increased serum ascorbate levels from micromolar to millimolar levels. P-AscH^- added to the gemcitabine + <em>nab</em>-paclitaxel (ASC) increased overall survival to 16 months compared to 8.3 months with gemcitabine + <em>nab</em>-paclitaxel (SOC) (HR = 0.46; 90 % CI 0.23, 0.92; p = 0.030). Median progression free survival was 6.2 (ASC) <em>vs.</em> 3.9 months (SOC) (HR = 0.43; 90 % CI 0.20, 0.92; p = 0.029). Adding P-AscH^- did not negatively impact quality of life or increase the frequency or severity of adverse events.</div></div><div><h3>Conclusions</h3><div>P-AscH⁻ infusions of 75 g three times weekly in patients with metastatic pancreatic cancer prolongs overall and progression free survival without detriment to quality of life or added toxicity (<span><span>ClinicalTrials.gov</span><svg><path></path></svg></span> number NCT02905578).</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"77 ","pages":"Article 103375"},"PeriodicalIF":10.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142381517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FMRP protects breast cancer cells from ferroptosis by promoting SLC7A11 alternative splicing through interacting with hnRNPM","authors":"Nan Wang ,&nbsp;Bin Shi ,&nbsp;Lu Ding ,&nbsp;Xu Zhang ,&nbsp;Xiaolan Ma ,&nbsp;Songlin Guo ,&nbsp;Xia Qiao ,&nbsp;Libin Wang ,&nbsp;Duan Ma ,&nbsp;Jia Cao","doi":"10.1016/j.redox.2024.103382","DOIUrl":"10.1016/j.redox.2024.103382","url":null,"abstract":"<div><div>Ferroptosis is a unique modality of regulated cell death that is driven by iron-dependent phospholipid peroxidation. N6-methyladenosine (m⁶A) RNA modification participates in varieties of cellular processes. However, it remains elusive whether m⁶A reader Fragile X Mental Retardation Protein (FMRP) are involved in the modulation of ferroptosis in breast cancer (BC). In this study, we found that FMRP expression was elevated and associated with poor prognosis and pathological stage in BC patients. Overexpression of FMRP induced ferroptosis resistance and exerted oncogenic roles by positively regulating a critical ferroptosis defense gene SLC7A11. Mechanistically, upregulated FMRP catalyzes m⁶A modification of SLC7A11 mRNA and further influences the SLC7A11 translation through METTL3-dependent manner. Further studies revealed that FMRP interacts with splicing factor hnRNPM to recognize the splice site and then modulated the exon skip splicing event of SLC7A11 transcript. Interestingly, SLC7A11-S splicing variant can effectively promote FMRP overexpression-induced ferroptosis resistance in BC cells. Moreover, our clinical data suggested that FMRP/hnRNPM/SLC7A11 expression were significantly increased in the tumor tissues, and this signal axis was important evaluation factors closely related to the worse survival and prognosis of BC patients. Overall, our results uncovered a novel regulatory mechanism by which high FMRP expression protects BC cells from undergoing ferroptosis. Targeting the FMRP–SLC7A11 axis has a dual effect of inhibiting ferroptosis resistance and tumor growth, which could be a promising therapeutic target for treating BC.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"77 ","pages":"Article 103382"},"PeriodicalIF":10.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142401121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxidative stress-related biomarkers as promising indicators of inflammatory bowel disease activity: A systematic review and meta-analysis","authors":"Armando Tratenšek ,&nbsp;Igor Locatelli ,&nbsp;Iztok Grabnar ,&nbsp;David Drobne ,&nbsp;Tomaž Vovk","doi":"10.1016/j.redox.2024.103380","DOIUrl":"10.1016/j.redox.2024.103380","url":null,"abstract":"<div><div>Oxidative stress is believed to play an important role in the pathogenesis of inflammatory bowel disease (IBD), specifically Crohn's disease (CD) and ulcerative colitis (UC). This meta-analysis aimed to identify and quantify the oxidative stress-related biomarkers in IBD and their associations with disease activity. We systematically searched Ovid MEDLINE, Ovid Embase, and Web of Science databases, identifying 54 studies for inclusion. Comparisons included: (i) active IBD versus healthy controls; (ii) inactive IBD versus healthy controls; (iii) active CD versus inactive CD; and (iv) active UC versus inactive UC. Our analysis revealed a significant accumulation of biomarkers of oxidative damage to biomacromolecules, coupled with reductions in various antioxidants, in both patients with active and inactive IBD compared to healthy controls. Additionally, we identified biomarkers that differentiate between active and inactive CD, including malondialdehyde, Paraoxonase 1, catalase, albumin, transferrin, and total antioxidant capacity. Similarly, levels of Paraoxonase 1, erythrocyte glutathione peroxidase, catalase, albumin, transferrin, and free thiols differed between active and inactive UC. Vitamins and carotenoids also emerged as potential disease activity biomarkers for CD and UC, but their intake should be monitored to obtain meaningful results. These findings emphasize the involvement of oxidative stress in the pathogenesis of IBD and highlight the potential of oxidative stress-related biomarkers as a minimally invasive and additional tool for monitoring the activity of IBD.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"77 ","pages":"Article 103380"},"PeriodicalIF":10.7,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142378220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of plasma-induced oxidation on NK cell immune checkpoint ligands: A computational-experimental approach","authors":"Pepijn Heirman ,&nbsp;Hanne Verswyvel ,&nbsp;Mauranne Bauwens ,&nbsp;Maksudbek Yusupov ,&nbsp;Jorrit De Waele ,&nbsp;Abraham Lin ,&nbsp;Evelien Smits ,&nbsp;Annemie Bogaerts","doi":"10.1016/j.redox.2024.103381","DOIUrl":"10.1016/j.redox.2024.103381","url":null,"abstract":"<div><div>Non-thermal plasma (NTP) shows promise as a potent anti-cancer therapy with both cytotoxic and immunomodulatory effects. In this study, we investigate the chemical and biological effects of NTP-induced oxidation on several key, determinant immune checkpoints of natural killer (NK) cell function. We used molecular dynamics (MD) and umbrella sampling simulations to investigate the effect of NTP-induced oxidative changes on the MHC-I complexes HLA-Cw4 and HLA-E. Our simulations indicate that these chemical alterations do not significantly affect the binding affinity of these markers to their corresponding NK cell receptor, which is supported with experimental read-outs of ligand expression on human head and neck squamous cell carcinoma cells after NTP application. Broadening our scope to other key ligands for NK cell reactivity, we demonstrate rapid reduction in CD155 and CD112, target ligands of the inhibitory TIGIT axis, and in immune checkpoint CD73 immediately after treatment. Besides these transient chemical alterations, the reactive species in NTP cause a cascade of downstream cellular reactions. This is underlined by the upregulation of the stress proteins MICA/B, potent ligands for NK cell activation, 24 h post treatment. Taken together, this work corroborates the immunomodulatory potential of NTP, and sheds light on the interaction mechanisms between NTP and cancer cells.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"77 ","pages":"Article 103381"},"PeriodicalIF":10.7,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of alternative oxidase (AOX) expression on mouse cerebral mitochondria bioenergetics","authors":"Belem Yoval-Sánchez ,&nbsp;Ivan Guerrero ,&nbsp;Fariha Ansari ,&nbsp;Zoya Niatsetskaya ,&nbsp;Max Siragusa ,&nbsp;Jordi Magrane ,&nbsp;Vadim Ten ,&nbsp;Csaba Konrad ,&nbsp;Marten Szibor ,&nbsp;Alexander Galkin","doi":"10.1016/j.redox.2024.103378","DOIUrl":"10.1016/j.redox.2024.103378","url":null,"abstract":"<div><div>Alternative oxidase (AOX) is an enzyme that transfers electrons from reduced quinone directly to oxygen without proton translocation. When AOX from <em>Ciona intestinalis</em> is xenotopically expressed in mice, it can substitute the combined electron-transferring activity of mitochondrial complexes III/IV. Here, we used brain mitochondria from AOX-expressing mice with such a chimeric respiratory chain to study respiratory control bioenergetic mechanisms.</div><div>AOX expression did not compromise the function of the mammalian respiratory chain at physiological conditions, however the complex IV inhibitor cyanide only partially blocked respiration by AOX-containing mitochondria. The relative fraction of cyanide-insensitive respiration increased at lower temperatures, indicative of a temperature-controlled attenuation of mammalian respiratory enzyme activity.</div><div>As AOX does not translocate protons, the mitochondrial transmembrane potential in AOX-containing mitochondria was more sensitive to cyanide during succinate oxidation than during malate/pyruvate-supported respiration. High concentrations of cyanide fully collapsed membrane potential during oxidation of either succinate or glycerol 3-phosphate, but not during malate/pyruvate-supported respiration. This confirms AOX's electroneutral redox activity and indicates differences in the proton-translocating capacity of dehydrogenases upstream of the ubiquinone pool. Our respiration data refutes previous proposals for quinone partitioning within the supercomplexes of the respiratory chain, instead supporting the concept of a single homogeneous, freely diffusing quinone pool.</div><div>Respiration with either succinate or glycerol 3-phosphate promotes reverse electron transfer (RET) towards complex I. AOX expression significantly decreased RET-induced ROS generation, with the effect more pronounced at low temperatures. Inhibitor-sensitivity analysis showed that the AOX-induced decrease in H₂O₂ release is due to the lower contribution of complex I to net ROS production during RET.</div><div>Overall, our findings provide new insights into the role of temperature as a mechanism to control respiration and highlight the utility of AOX as a genetic tool to characterize both the distinct pathways of oxygen reduction and the role of redox control in RET.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"77 ","pages":"Article 103378"},"PeriodicalIF":10.7,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142378219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}