Redox Biology最新文献

{"title":"Sphaeropsidin A covalently binds to Cys 151 of Keap1 to attenuate LPS-induced acute pneumonia in mice","authors":"Kang Yang ,&nbsp;Qing-Tong Han ,&nbsp;Rong-Xue Xing ,&nbsp;Zhi-Ying Li ,&nbsp;Lin-Tao Xu ,&nbsp;Lu-Zhou Chen ,&nbsp;Lan Xiang ,&nbsp;Dong-Mei Ren ,&nbsp;Qing-Wen Hu ,&nbsp;Xiao-Ning Wang ,&nbsp;Tao Shen","doi":"10.1016/j.redox.2025.103621","DOIUrl":"10.1016/j.redox.2025.103621","url":null,"abstract":"<div><h3>Introduction</h3><div>Kelch ECH-associating protein 1 (Keap1)-Nuclear factor erythroid 2-related factor 2 (Nrf2) axis is crucial for regulating oxidative stress and inflammatory responses in acute pneumonia. Sphaeropsidin A (SA) is a antioxidant diterpenoid isolated from <em>Sphaeropsis sapinea</em> f. sp. <em>cupressi,</em> discovered as a novel Nrf2 agonist by our research group previously. However, the accurate function and mechanism of SA in treating acute pneumonia are still unknown.</div></div><div><h3>Methods</h3><div>The therapeutic effect of SA was evaluated in LPS-induced acute pneumonia in mice. The underlying mechanism of action was then analyzed by transcriptomics. The direct target of SA was identified through the synthesis of SA-biotin probe, and the binding amino acid residues were found and verified by LC-MS/MS analysis and site-specific mutation. Finally, knockout mice were employed to verify the mechanism of SA.</div></div><div><h3>Results</h3><div>Our data indicated that SA significantly inhibited LPS-induced acute pneumonia in mice via up-regulating Nrf2, inhibiting NLRP3 inflammasome and NF-κB activation, and identified Keap1 as the direct target of SA. Specifically, the effective dose of SA in mice was only 2 mg/kg. SA selectively covalent bound to Keap1 in cysteine 151 residue (Cys151). SA mediated the activation of Nrf2 and reduced the level of ROS, thereby inhibiting the NF-κB and NLRP3 inflammasome. Besides, SA formed hydrogen bond with ASP48 of ASC, blocking its oligomerization and inhibiting the activation of NLRP3 inflammasome.</div></div><div><h3>Conclusion</h3><div>This study indicates that SA might be a new covalent molecule of Keap1 to activate Nrf2, and is a promising drug candidate or lead molecule for the therapy of acute pneumonia through regulating Nrf2/NF-κB/NLRP3 inflammasome axis.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"82 ","pages":"Article 103621"},"PeriodicalIF":10.7,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747331","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":"Decoding ischemic stroke: Perspectives on the endoplasmic reticulum, mitochondria, and their crosstalk","authors":"Chuxin Zhang ,&nbsp;Xin Lan ,&nbsp;Qingguo Wang ,&nbsp;Yuxiao Zheng,&nbsp;Jialin Cheng,&nbsp;Jinhua Han,&nbsp;Changxiang Li ,&nbsp;Fafeng Cheng ,&nbsp;Xueqian Wang","doi":"10.1016/j.redox.2025.103622","DOIUrl":"10.1016/j.redox.2025.103622","url":null,"abstract":"<div><div>Stroke is known for its high disability and mortality rates. Ischemic stroke (IS), the most prevalent form, imposes a considerable burden on affected individuals. Nevertheless, existing treatment modalities are hindered by limitations, including narrow therapeutic windows, substantial adverse effects, and suboptimal neurological recovery. Clarifying the pathological mechanism of IS is a prerequisite for developing new therapeutic strategies. In this context, the functional disruption of mitochondria, the endoplasmic reticulum (ER), and the crosstalk mechanisms between them have garnered increasing attention for their contributory roles in the progression of IS. Therefore, this review provides a comprehensive summary of the current pathomechanisms associated with the involvement of the ER and mitochondria in IS, emphasising Ca²⁺ destabilization homeostasis, ER stress, oxidative stress, disordered mitochondrial quality control, and mitochondrial transfer. Additionally, this article highlights the functional interaction between the ER and mitochondria, as well as the mitochondrial-ER contacts (MERCs) that structurally connect mitochondria and the ER, aiming to provide ideas and references for the research and treatment of IS.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"82 ","pages":"Article 103622"},"PeriodicalIF":10.7,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783830","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":"Repression of oxidative phosphorylation by NR2F2, MTERF3 and GDF15 in human skin under high-glucose stress","authors":"S. Ley-Ngardigal ,&nbsp;S. Claverol ,&nbsp;L. Sobilo ,&nbsp;M. Moreau ,&nbsp;C. Hubert ,&nbsp;J. Goupil ,&nbsp;A. Poulignon ,&nbsp;W. Mahfouf ,&nbsp;H. Fatrouni ,&nbsp;L. Dard ,&nbsp;M. Juan ,&nbsp;L. Gales ,&nbsp;A. Merched ,&nbsp;C. Tokarski ,&nbsp;E. Leblanc ,&nbsp;A. Galinier ,&nbsp;D. Lacombe ,&nbsp;H.R. Rezvani ,&nbsp;F. Bellvert ,&nbsp;K. Pays ,&nbsp;R. Rossignol","doi":"10.1016/j.redox.2025.103613","DOIUrl":"10.1016/j.redox.2025.103613","url":null,"abstract":"<div><div>Lifestyle factors such as a Western diet or metabolic diseases like diabetes disrupt glucose homeostasis and induce stress responses, yet their impact on skin metabolism and structural integrity remains poorly understood. Here, we performed multiomic and bioenergetic analyses of human dermal fibroblasts (HDFs), human equivalent dermis (HED), human reconstructed skin (HRS), and skin explants from diabetic patients. We found that 12 mM glucose stress represses oxidative phosphorylation (OXPHOS) through a dual mechanism: the glucose-dependent nuclear receptor NR2F2 activates mitochondrial transcription termination factor 3 (MTERF3) while inhibiting growth-differentiation factor 15 (GDF15). Promoter assays revealed that MTERF3 is regulated by NR2F2 and MYCN, whereas GDF15 is modulated by NR2F2 and FOS. Consequently, OXPHOS proteins and mitochondrial respiration were suppressed, and MTERF3 overexpression additionally interfered with collagen biosynthesis. In contrast, GDF15 supplementation fully rescued hyperglycemia-induced bioenergetic and metabolomic alterations, suggesting a pharmacological strategy to mitigate hyperglycemic damage in the skin. Finally, silencing GDF15 or TFAM impaired fibroblast haptotaxis and skin reconstruction, underscoring the crucial role of mitochondrial energetics in dermal structure and function. Collectively, these findings identify the NR2F2–MTERF3–GDF15 axis as a key mediator of OXPHOS suppression and highlight a potential therapeutic target to preserve skin integrity under hyperglycemic stress.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"82 ","pages":"Article 103613"},"PeriodicalIF":10.7,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747183","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":"Design of anti-depressant phosphodiester amino acidic Keap1-Nrf2 protein-protein interaction inhibitors","authors":"Yi Sun ,&nbsp;Jue Wang ,&nbsp;Wenxin Ding ,&nbsp;Qingqing Qin ,&nbsp;Rui Wang ,&nbsp;Ruizhi Yu ,&nbsp;Jianyu Yan ,&nbsp;Ruilin Hou ,&nbsp;Guodong Liu ,&nbsp;Xiangming Cai ,&nbsp;Zhuo Qu ,&nbsp;Wannian Zhang ,&nbsp;Jianqiang Yu ,&nbsp;Chengguo Xing ,&nbsp;Chunlin Zhuang","doi":"10.1016/j.redox.2025.103620","DOIUrl":"10.1016/j.redox.2025.103620","url":null,"abstract":"<div><div>Inhibiting the protein-protein interaction (PPI) between Keap1 and Nrf2 is theoretically an effective and safe strategy for activation of Nrf2 pathway to treat major depressive disorder (MDD). In this study, through bioinformatic analysis of the brain tissues and peripheral blood of MDD patients and depressive mice, we confirmed the involvement of oxidative stress, inflammation, and the Keap1-Nrf2 pathway in depression. Subsequently, we developed a series of phosphodiester amino acidic diaminonaphthalene compounds as Keap1-Nrf2 PPI inhibitors for the first time. Screening using the LPS-stimulated SH-SY5Y and BV2 cell models identified compound 4–95 showing the best anti-oxidative stress and anti-inflammatory efficacy. The ability of 4–95 to penetrate the blood-brain-barrier was significantly enhanced. In a chronic unpredictable mild stress mouse model, treatment with 4–95 effectively ameliorated anxiety and depression behavior and restored serum neurotransmitter levels by promoting the Nrf2 nuclear translocation. Consequently, oxidative stress was reduced, and the expression of synaptic plasticity biomarkers, such as postsynaptic density protein 95 (PSD95) and synapsin 1 (SYN1) were significantly increased, suggesting the recovery of neuronal function. Collectively, our findings demonstrate that the Keap1-Nrf2 PPI inhibitor holds great promise as a preclinical candidate for the treatment of depression.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"82 ","pages":"Article 103620"},"PeriodicalIF":10.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747182","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":"Corrigendum to \"Diminished α7 nicotinic acetylcholine receptor (α7nAChR) rescues amyloid-β induced atrial remodeling by oxi-CaMKII/MAPK/AP-1 axis-mediated mitochondrial oxidative stress\" [Redox Biol. 59 (2023) 102594].","authors":"Jikai Zhao, Liming Yu, Xiaodong Xue, Yinli Xu, Tao Huang, Dengyue Xu, Zhishang Wang, Linyu Luo, Huishan Wang","doi":"10.1016/j.redox.2025.103604","DOIUrl":"https://doi.org/10.1016/j.redox.2025.103604","url":null,"abstract":"","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":" ","pages":"103604"},"PeriodicalIF":10.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143731507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coronin 1a-mediated F-actin disassembly controls effector function in murine neutrophils","authors":"Anton Shaverskyi ,&nbsp;Jan Hegermann ,&nbsp;Korbinian Brand ,&nbsp;Kyeong-Hee Lee ,&nbsp;Niko Föger","doi":"10.1016/j.redox.2025.103618","DOIUrl":"10.1016/j.redox.2025.103618","url":null,"abstract":"<div><div>The double-edged role of neutrophils in effective host defense and harmful pathology is an emerging topic in clinical research. Neutrophils release highly potent antimicrobial granule compounds and reactive oxygen species (ROS) that can also be detrimental to the host and promote inflammatory diseases and cancer. Here we show that disassembly of F-actin greatly facilitates ROS production and degranulation in neutrophils. Utilizing neutrophils from Coronin 1a (Coro1a)-deficient mice, our data reveal that the actin-regulatory protein Coro1a controls this spatial F-actin deconstruction and concomitantly forms a signaling complex with Rac-GTPases, thereby promoting activation and translocation of Rac to the membrane during neutrophil activation. This functional activity of Coro1a was critical for neutrophil granule exocytosis and the activation of the NADPH oxidase complex. Consistent with these findings, impaired ROS production in <em>Coro1a</em>-deficient neutrophils was rescued by pharmacological promotion of actin depolymerization or activation of Rac. Together, our findings suggest that the Coro1a/Rac signaling hub acts as a central regulatory element that coordinates actin cytoskeletal reorganization required for the execution of neutrophil effector functions. Since Coro1a is highly conserved between mice and humans and associated with human immunodeficiency, our results are also relevant for human biomedical studies.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"82 ","pages":"Article 103618"},"PeriodicalIF":10.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724111","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":"Targeting PIM1 by Bruceine D attenuates skin fibrosis via myofibroblast ferroptosis","authors":"Jianzhang Wang ,&nbsp;Yajuan Song ,&nbsp;Xiaoying Tan ,&nbsp;Tong Wang ,&nbsp;Yi Shi ,&nbsp;Xingbo Xu ,&nbsp;Juan Du ,&nbsp;Zhou Yu ,&nbsp;Baoqiang Song","doi":"10.1016/j.redox.2025.103619","DOIUrl":"10.1016/j.redox.2025.103619","url":null,"abstract":"<div><div>Skin pan-fibrosis diseases—such as hypertrophic scar (HS), keloid scar (KS), and systemic sclerosis (SSc)—pose significant threats to patients' health and quality of life. In this study, the authors conducted both in vivo and in vitro experiments and discovered that the serine/threonine kinase PIM1 is upregulated in the myofibroblasts of human HS, KS, and SSc tissues, as well as in various animal models of skin fibrosis. Overexpression of PIM1 enhanced the profibrotic phenotypes of human hypertrophic scar fibroblasts (HSFs), which serve as key effector cells in the pathogenesis of skin pan-fibrosis diseases. Through high-throughput screening and subsequent laboratory assays, we identified the small molecule Bruceine D (BD) as a direct binder of PIM1. BD promoted ferroptosis in HSFs by selectively suppressing the PIM1-KEAP1-NRF2 pathway through augmented degradation of PIM1. In various in vivo models-including a hypertrophic scar mouse model, a rabbit ear hypertrophic scar model, and a bleomycin (BLM)-induced skin fibrosis mouse model-BD effectively attenuated fibrotic phenotypes. Collectively, these findings demonstrate that PIM1 serves as a common biomarker and therapeutic target for skin pan-fibrosis diseases. BD mitigates skin fibrosis by activating ferroptosis via PIM1 inhibition, highlighting its great translational potential and high promise to be developed to a clinical drug in treating these conditions, especially those with abnormally elevated PIM1 expression.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"82 ","pages":"Article 103619"},"PeriodicalIF":10.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747180","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":"Effects of Omega-3 PUFAs on lipid profiles and antioxidant response in depressed adolescents: A metabolomic and lipidomic study","authors":"Jinfeng Wang ,&nbsp;Shuhui Li ,&nbsp;Dandan Wang ,&nbsp;Yan Gao ,&nbsp;Qian Wang ,&nbsp;Tianqi Wang ,&nbsp;Guanghai Wang ,&nbsp;Daihui Peng ,&nbsp;Yi Qiao ,&nbsp;Jiansong Zhou ,&nbsp;Lei Feng ,&nbsp;Xiaowen Hu ,&nbsp;Chunling Wan","doi":"10.1016/j.redox.2025.103617","DOIUrl":"10.1016/j.redox.2025.103617","url":null,"abstract":"<div><div>Adolescent depression is a significant global health challenge, with many patients responding inadequately to antidepressant treatments. Omega-3 polyunsaturated fatty acids (ω3 PUFAs) have been proposed as a potential adjunctive treatment, but their precise mechanisms remain poorly understood. This study aimed to explore the mechanisms through which ω3 PUFAs exert their antidepressant effects and to identify potential biomarkers for their therapeutic response. A comprehensive assessment of plasma metabolomic and erythrocyte membrane lipidomic was performed on 51 depressed adolescents who were randomly assigned to received either ω3 PUFAs plus paroxetine (n = 27) or paroxetine alone (n = 24) for 12 weeks. Following ω3 PUFA supplementation, phospholipid metabolism emerged as the most significantly altered pathway. ω3 PUFAs markedly influenced the composition of membrane fatty acids, significantly increasing the ω3 PUFA content, decreasing the ω6/ω3 PUFA ratio, and increasing membrane fluidity. Notably, ω3 PUFAs reduced lipid peroxidation in both plasma and cell membranes while enhancing antioxidant capacity in the membranes. Moreover, alterations in phospholipids and membrane function were significantly correlated with improvements in depressive symptoms and cognitive function. Importantly, ω3 PUFA supplementation resulted in greater improvement in clinical symptoms compared to the non-supplemented group exclusively in the subgroup with high baseline oxidative damage levels. This study suggests that ω3 PUFAs promoted phospholipid integration and alleviated oxidative stress, which may account for their antidepressant effects. Lipid oxidation biomarkers could help identify patients likely to benefit from ω3 PUFA supplementation. These findings advance our understanding of the mechanism and clinical application of ω3 PUFAs in treating adolescent depression.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"82 ","pages":"Article 103617"},"PeriodicalIF":10.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734885","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":"Extracellular vesicle-packaged GBP2 from macrophages aggravates sepsis-induced acute lung injury by promoting ferroptosis in pulmonary vascular endothelial cells","authors":"Zhixi Li ,&nbsp;Yue Bu ,&nbsp;Cheng Wang ,&nbsp;Yongjing Yu ,&nbsp;Lei Han ,&nbsp;Chang Liu ,&nbsp;Guangmin Chen ,&nbsp;Chenglong Li ,&nbsp;Yan Zhang ,&nbsp;Hang Cao ,&nbsp;Zhaoxue Ma ,&nbsp;Ziyong Yue","doi":"10.1016/j.redox.2025.103614","DOIUrl":"10.1016/j.redox.2025.103614","url":null,"abstract":"<div><div>Macrophages play a critical role in the development of sepsis-induced acute lung injury (si-ALI), with extracellular vesicles (EVs) acting as crucial mediators. However, the effects and mechanisms of macrophage-derived EVs on si-ALI remain unclear. This study demonstrated that macrophage-derived EVs induce endothelial ferroptosis and barrier disruption during sepsis. Through proteomic sequencing and reanalysis of transcriptomic and single-cell sequencing data, guanylate-binding protein 2 (GBP2) was identified as a key EV molecule. Elevated GBP2 expression was observed in EVs and monocytes from the peripheral blood of sepsis patients, in LPS-stimulated THP-1 and RAW264.7 cells and their secreted EVs, and in macrophages within the lungs of CLP mice. Additionally, GBP2 expression in EVs showed a positive correlation with vascular barrier injury biomarkers, including ANGPT2, Syndecan-1, and sTM. Modulating GBP2 levels in macrophage-derived EVs affected EV-induced ferroptosis in endothelial cells. The mechanism by which GBP2 binds directly to OTUD5 and promotes GPX4 ubiquitination was elucidated using RNA interference, adeno-associated virus transfection, and endothelial-specific Gpx4 knockout mice. A high-throughput screening of small-molecule compounds targeting GBP2 was conducted. Molecular docking, molecular dynamics simulations, and cellular thermal shift assays further confirmed that Plantainoside D (PD) has a potent binding affinity for GBP2. PD treatment inhibited the interaction between GBP2 and OTUD5, leading to a reduction in GPX4 ubiquitination. Further research revealed that PD treatment enhanced the pulmonary protective effects of GBP2 inhibition. In conclusion, this study explored the role of EV-mediated signaling between macrophages and pulmonary vascular endothelial cells in si-ALI, highlighting the GBP2-OTUD5-GPX4 axis as a driver of endothelial ferroptosis and lung injury. Targeting this signaling axis presents a potential therapeutic strategy for si-ALI.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"82 ","pages":"Article 103614"},"PeriodicalIF":10.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724884","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":"Hemoglobin in the brain frontal lobe tissue of patients with Alzheimer’s disease is susceptible to reactive nitrogen species-mediated oxidative damage","authors":"M.J. Smallwood ,&nbsp;M. Abu Alghayth ,&nbsp;A.R. Knight ,&nbsp;K. Tveen-Jensen ,&nbsp;A.R. Pitt ,&nbsp;C.M. Spickett ,&nbsp;D. Llewellyn ,&nbsp;G. Pula ,&nbsp;A. Wearn ,&nbsp;A. Vanhatalo ,&nbsp;A.M. Jones ,&nbsp;P. Francis ,&nbsp;E. Coulthard ,&nbsp;P.G. Kehoe ,&nbsp;P.G. Winyard","doi":"10.1016/j.redox.2025.103612","DOIUrl":"10.1016/j.redox.2025.103612","url":null,"abstract":"<div><div>Brain inflammation in Alzheimer’s disease (AD) involves reactive nitrogen species (RNS) generation. Protein contents of 3-nitrotyrosine, a product of RNS generation, were assessed in frontal lobe brain homogenates from patients with AD, patients with vascular dementia (VaD) and non-dementia (ND) controls. Western blotting revealed a dominant 15 kDa nitrated protein band in both dementia (AD/VaD) and ND frontal lobe brain tissue. Surprisingly, this protein band was identified by mass spectrometry as hemoglobin, an erythrocytic protein. The same band stained positively when western blotted using an anti-hemoglobin antibody. On western blots, the median (IQR) normalized staining intensity for 3-nitrotyrosine in hemoglobin was increased in both AD [1.71 (1.20–3.05) AU] and VaD [1.50 (0.59–3.04) AU] brain tissue compared to ND controls [0.41 (0.09–0.75) AU] (Mann-Whitney <em>U</em> test: AD v ND, P &lt; 0.0005; VaD v ND, P &lt; 0.05; n = 11). The median normalized staining of the nitrated hemoglobin band was higher in advanced AD patients compared with early-stage AD (P &lt; 0.005). The median brain tissue NO₂⁻ levels (nmol/mg protein) were significantly higher in AD samples than in ND controls (P &lt; 0.05). Image analysis of western blots of lysates from peripheral blood erythrocytes suggested that hemoglobin nitration was increased in AD compared to ND (P &lt; 0.05; n = 4 in each group). Total protein-associated 3-nitrotyrosine was measured by an electrochemiluminescence-based immunosorbent assay, but showed no statistically significant differences between AD, VaD and ND. Females showed larger increases in hemoglobin nitration and NO₂⁻ levels between disease and control groups compared to males, although the group sizes in these sub-analyses were small. In conclusion, the extent of hemoglobin nitration was increased in AD and VaD brain frontal lobe tissue compared with ND. We propose that reactive nitrogen species-mediated damage to hemoglobin may be involved in the pathogenesis of AD.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"82 ","pages":"Article 103612"},"PeriodicalIF":10.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143759611","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}