Pub Date : 2026-02-01Epub Date: 2025-12-11DOI: 10.1016/j.abb.2025.110702
Qiguo Wang , Qin Wang , Xiangyu Meng , Xiaoman Ji , Ting Wang
Ferroptosis has emerged as a critical mechanism contributing to renal tubular epithelial cell injury in diabetic nephropathy (DN), though its mechanisms require further elucidation. This study investigated the expression and regulatory role of long non-coding RNA small nucleolar RNA host gene 6 (SNHG6) in DN-associated ferroptosis. Bioinformatics analysis confirmed the significant downregulation of SNHG6 in DN and its diagnostic value, while real-time quantitative PCR experiments demonstrated that high glucose treatment for 24 h induced the downregulation of SNHG6 in renal tubular epithelial cells HK-2. Overexpression of SNHG6 alleviated high glucose-triggered ferroptosis of HK-2 cells by promoting the expression of glutathione peroxidase 4 and reducing the expression of acyl-CoA synthetase long chain family member 4 and transferrin receptor, manifested by increased cell viability, decreased lactate dehydrogenase activity, and suppressed lipid peroxidation. Mechanistic studies revealed that SNHG6 stabilized YY1 mRNA by promoting its binding to the FUS RNA-binding protein, subsequently activating the PI3K/AKT/GSK-3β signaling pathway to exert a protective effect. Blocking the YY1-PI3K signaling cascade abolished SNHG6 overexpression-mediated inhibition of high glucose-induced cellular ferroptosis. In summary, SNHG6 exerts renoprotective effects in DN by modulating ferroptosis through the YY1-PI3K/AKT/GSK-3β axis.
{"title":"LncRNA SNHG6 attenuates ferroptosis in high glucose-treated renal tubular epithelial cells by stabilizing YY1 to activate the PI3K/AKT/GSK-3β pathway","authors":"Qiguo Wang , Qin Wang , Xiangyu Meng , Xiaoman Ji , Ting Wang","doi":"10.1016/j.abb.2025.110702","DOIUrl":"10.1016/j.abb.2025.110702","url":null,"abstract":"<div><div>Ferroptosis has emerged as a critical mechanism contributing to renal tubular epithelial cell injury in diabetic nephropathy (DN), though its mechanisms require further elucidation. This study investigated the expression and regulatory role of long non-coding RNA small nucleolar RNA host gene 6 (SNHG6) in DN-associated ferroptosis. Bioinformatics analysis confirmed the significant downregulation of SNHG6 in DN and its diagnostic value, while real-time quantitative PCR experiments demonstrated that high glucose treatment for 24 h induced the downregulation of SNHG6 in renal tubular epithelial cells HK-2. Overexpression of SNHG6 alleviated high glucose-triggered ferroptosis of HK-2 cells by promoting the expression of glutathione peroxidase 4 and reducing the expression of acyl-CoA synthetase long chain family member 4 and transferrin receptor, manifested by increased cell viability, decreased lactate dehydrogenase activity, and suppressed lipid peroxidation. Mechanistic studies revealed that SNHG6 stabilized YY1 mRNA by promoting its binding to the FUS RNA-binding protein, subsequently activating the PI3K/AKT/GSK-3β signaling pathway to exert a protective effect. Blocking the YY1-PI3K signaling cascade abolished SNHG6 overexpression-mediated inhibition of high glucose-induced cellular ferroptosis. In summary, SNHG6 exerts renoprotective effects in DN by modulating ferroptosis through the YY1-PI3K/AKT/GSK-3β axis.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110702"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145740661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The indole monooxygenase system from Acinetobacter baumannii is a two-component flavoprotein that catalyzes the monooxygenation of indole. The system consists of the flavoprotein reductase (IndR) and the oxygenase (IndOx). IndR generates reduced FAD (FADH−) to IndOx using NADH. The pre-equilibration of IndOx with FADH− inhibits the formation of C4a-hydroperoxyflavin. In contrast, the presence of indole facilitates the formation of C4a-hydroperoxyflavin. The structural study reveals a dynamic loop at the active site, which has never been demonstrated in this class of enzyme, resulting in two conformations of IndOx. The closed conformation prevents the formation of the C4a-hydroperoxyflavin, whereas the binding of indole directs the open conformation, allowing for the formation of C4a-hydroperoxyflavin. The kinetic mechanism of both components was elucidated using rapid kinetics. The binding of indole to form a ternary complex is a preferential random-order mechanism in which indole preferentially binds to IndOx:C4a-hydroperoxyflavin, compared with IndOx:FADH− complex. The turnover number in the presence of both components to produce 3-hydroxyindole demonstrated that either the release of oxidized FAD or the release of monooxygenated product from the IndOx active site, or partially both, entirely limits the catalytic reaction. The solvent isotope effect on the step of the structural rearrangement of the monooxygenated product to form 3-hydroxyindole in this study supports the previously proposed epoxide-dihydrodiol model. This step is significantly slower than the turnover number, indicating that the monooxygenated indole is released and then undergoes a non-enzymatic structural rearrangement outside the active site, leading to the formation of 3-hydroxyindole.
{"title":"Structure and reaction mechanisms of a two-component indole monooxygenase from Acinetobacter baumannii","authors":"Kanyarat Suksomjaisaman , Konrawee Thananon , Montisa Mangkalee , Kittisak Thotsaporn , Ruchanok Tinikul , Albert Schulte , Kittikhun Wangkanont , Supaart Sirikantaramas , Jeerus Sucharitakul , Pimchai Chaiyen","doi":"10.1016/j.abb.2025.110681","DOIUrl":"10.1016/j.abb.2025.110681","url":null,"abstract":"<div><div>The indole monooxygenase system from <em>Acinetobacter baumannii</em> is a two-component flavoprotein that catalyzes the monooxygenation of indole. The system consists of the flavoprotein reductase (IndR) and the oxygenase (IndOx). IndR generates reduced FAD (FADH<sup>−</sup>) to IndOx using NADH. The pre-equilibration of IndOx with FADH<sup>−</sup> inhibits the formation of C4a-hydroperoxyflavin. In contrast, the presence of indole facilitates the formation of C4a-hydroperoxyflavin. The structural study reveals a dynamic loop at the active site, which has never been demonstrated in this class of enzyme, resulting in two conformations of IndOx. The closed conformation prevents the formation of the C4a-hydroperoxyflavin, whereas the binding of indole directs the open conformation, allowing for the formation of C4a-hydroperoxyflavin. The kinetic mechanism of both components was elucidated using rapid kinetics. The binding of indole to form a ternary complex is a preferential random-order mechanism in which indole preferentially binds to IndOx:C4a-hydroperoxyflavin, compared with IndOx:FADH<sup>−</sup> complex. The turnover number in the presence of both components to produce 3-hydroxyindole demonstrated that either the release of oxidized FAD or the release of monooxygenated product from the IndOx active site, or partially both, entirely limits the catalytic reaction. The solvent isotope effect on the step of the structural rearrangement of the monooxygenated product to form 3-hydroxyindole in this study supports the previously proposed epoxide-dihydrodiol model. This step is significantly slower than the turnover number, indicating that the monooxygenated indole is released and then undergoes a non-enzymatic structural rearrangement outside the active site, leading to the formation of 3-hydroxyindole.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110681"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145653549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-10DOI: 10.1016/j.abb.2025.110701
Krishna Singh Bisht, Manisha Kumari, Tushar Kanti Maiti
Synucleinopathies, such as Parkinson's Disease, involve widespread intracellular protein aggregates. α-synuclein (αSyn) protein contributes majorly to these aggregates called as Lewy Bodies, which are linked to neurodegeneration. αSyn has been shown to transmit from infected to healthy neurons, thus spreading the pathology. During its transmission, αSyn is also known to activate microglia by interacting with the glial surface receptors such as Toll-Like receptors (TLRs). This activation is implicated in the production of interleukins and proinflammatory cytokines, exacerbating neuronal death through chronic neuroinflammation. However, the mechanism of αSyn and TLR interaction is not well elucidated. In this study, using biophysical methods and in the HEK-TLR2 cells, we demonstrate that αSyn N-terminal has a higher binding affinity with TLR2. This interaction is mediated through the lysine residues in the second and third KTKEGV motifs of αSyn. The lysine to alanine mutations in the N-terminal KTKGEV motifs perturb the αSyn/TLR2 interaction. We also demonstrate that the lysine residues of 2nd and 3rd KTKEGV motifs are critical for αSyn-mediated TLR2 activation. Our study demonstrates that the N-terminal KTKEGV lysine residues facilitate interaction with TLR2, thereby regulating αSyn-mediated neuroinflammation.
{"title":"N-terminal KTKEGV motif lysine residues of α-Synuclein are critical for TLR2 interaction and activation","authors":"Krishna Singh Bisht, Manisha Kumari, Tushar Kanti Maiti","doi":"10.1016/j.abb.2025.110701","DOIUrl":"10.1016/j.abb.2025.110701","url":null,"abstract":"<div><div>Synucleinopathies, such as Parkinson's Disease, involve widespread intracellular protein aggregates. α-synuclein (αSyn) protein contributes majorly to these aggregates called as Lewy Bodies, which are linked to neurodegeneration. αSyn has been shown to transmit from infected to healthy neurons, thus spreading the pathology. During its transmission, αSyn is also known to activate microglia by interacting with the glial surface receptors such as Toll-Like receptors (TLRs). This activation is implicated in the production of interleukins and proinflammatory cytokines, exacerbating neuronal death through chronic neuroinflammation. However, the mechanism of αSyn and TLR interaction is not well elucidated. In this study, using biophysical methods and in the HEK-TLR2 cells, we demonstrate that αSyn N-terminal has a higher binding affinity with TLR2. This interaction is mediated through the lysine residues in the second and third KTKEGV motifs of αSyn. The lysine to alanine mutations in the N-terminal KTKGEV motifs perturb the αSyn/TLR2 interaction. We also demonstrate that the lysine residues of 2nd and 3rd KTKEGV motifs are critical for αSyn-mediated TLR2 activation. Our study demonstrates that the N-terminal KTKEGV lysine residues facilitate interaction with TLR2, thereby regulating αSyn-mediated neuroinflammation.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110701"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145740666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-04DOI: 10.1016/j.abb.2025.110680
Tanmoy Saha , Sayantani Chatterjee , Saurabh Das
Following dissociation of phenolic–OH, quinalizarin generates anions that face repulsion from DNA posing a challenge to its use as an alternative to anthracyclines. An earlier attempt to prevent anion formation by converting all –OH groups to acetyl units had resulted in increased binding with DNA. Although such increase in binding with DNA compared to quinalizarin was observed, owing to a simultaneous increase in steric bulk, a doubt had remained as to whether it was a true manifestation of acetylation. The suspicion being, whether increase in binding constant overcoming repulsion was offset in any way by increase in steric bulk. This in silico DNA binding investigation aims to realize what would be the outcome if one exclusively acetylates the –OH responsible for mono-anion formation. Not having experimental binding information on mono-acetylated species, DNA binding was tried by an in silico approach. Analysis reveals tetra-acetylated quinalizarin was better than the mono-acetylated form; increase due to groove binding, rather than by intercalation being the correct manifestation. Three forms of quinalizarin and the standard drug doxorubicin were investigated by a general DNA model (PDBID:1BNA) and subsequently by intercalation specific (PDBID:1Z3F) and groove binding specific (PDBID:101D) models. ADMET profiles for drug-like properties were done. Information from in silico analysis suggest simpler analogues of anthracyclines are economical and acetylation of all –OH groups of quinalizarin is biologically significant.
{"title":"An in silico DNA binding investigation using DFT, molecular docking and molecular dynamics simulation on mono and tetra acetylated derivatives of quinalizarin to enable a comparison with experimental DNA binding data","authors":"Tanmoy Saha , Sayantani Chatterjee , Saurabh Das","doi":"10.1016/j.abb.2025.110680","DOIUrl":"10.1016/j.abb.2025.110680","url":null,"abstract":"<div><div>Following dissociation of phenolic–OH, quinalizarin generates anions that face repulsion from DNA posing a challenge to its use as an alternative to anthracyclines. An earlier attempt to prevent anion formation by converting all –OH groups to acetyl units had resulted in increased binding with DNA. Although such increase in binding with DNA compared to quinalizarin was observed, owing to a simultaneous increase in steric bulk, a doubt had remained as to whether it was a true manifestation of acetylation. The suspicion being, whether increase in binding constant overcoming repulsion was offset in any way by increase in steric bulk. This <em>in silico</em> DNA binding investigation aims to realize what would be the outcome if one exclusively acetylates the –OH responsible for mono-anion formation. Not having experimental binding information on mono-acetylated species, DNA binding was tried by an <em>in silico</em> approach. Analysis reveals tetra-acetylated quinalizarin was better than the mono-acetylated form; increase due to groove binding, rather than by intercalation being the correct manifestation. Three forms of quinalizarin and the standard drug doxorubicin were investigated by a general DNA model (PDBID:<span><span>1BNA</span><svg><path></path></svg></span>) and subsequently by intercalation specific (PDBID:<span><span>1Z3F</span><svg><path></path></svg></span>) and groove binding specific (PDBID:<span><span>101D</span><svg><path></path></svg></span>) models. ADMET profiles for drug-like properties were done. Information from <em>in silico</em> analysis suggest simpler analogues of anthracyclines are economical and acetylation of all –OH groups of quinalizarin is biologically significant.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110680"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145696006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-22DOI: 10.1016/j.abb.2025.110714
Huiyan Qu , Weidong Xie , Jing Zhang , Zhilin Liu , Shuai Chang , Fangwei Liu
Silicon dioxide (SiO2) is a major occupational hazard causing irreversible pulmonary fibrosis. While epithelial-mesenchymal transition (EMT) is implicated in fibrosis, its regulation remains unclear. This study identified serum exosomal miR-4687-5p as significantly down-regulated in silicosis patients. Dual-luciferase assays confirmed β-catenin as its direct target. Using the exosome inhibitor GW4869, we demonstrated exosome-mediated transfer of miR-4687-5p from macrophages to lung epithelial cells. Treating epithelial cells with a miR-4687-5p mimic revealed its role in modulating EMT by inhibiting β-catenin nuclear translocation. Crucially, silencing β-catenin in murine lung tissue significantly attenuated silica-induced pulmonary fibrosis. Our findings establish that exosomal miR-4687-5p alleviates silicosis-related fibrosis by targeting β-catenin to suppress EMT, highlighting miR-4687-5p as a potential therapeutic target.
{"title":"Exosomal miR-4687-5p alleviates silica-induced fibrosis by inhibiting EMT via β-catenin targeting","authors":"Huiyan Qu , Weidong Xie , Jing Zhang , Zhilin Liu , Shuai Chang , Fangwei Liu","doi":"10.1016/j.abb.2025.110714","DOIUrl":"10.1016/j.abb.2025.110714","url":null,"abstract":"<div><div>Silicon dioxide (SiO<sub>2</sub>) is a major occupational hazard causing irreversible pulmonary fibrosis. While epithelial-mesenchymal transition (EMT) is implicated in fibrosis, its regulation remains unclear. This study identified serum exosomal miR-4687-5p as significantly down-regulated in silicosis patients. Dual-luciferase assays confirmed β-catenin as its direct target. Using the exosome inhibitor GW4869, we demonstrated exosome-mediated transfer of miR-4687-5p from macrophages to lung epithelial cells. Treating epithelial cells with a miR-4687-5p mimic revealed its role in modulating EMT by inhibiting β-catenin nuclear translocation. Crucially, silencing β-catenin in murine lung tissue significantly attenuated silica-induced pulmonary fibrosis. Our findings establish that exosomal miR-4687-5p alleviates silicosis-related fibrosis by targeting β-catenin to suppress EMT, highlighting miR-4687-5p as a potential therapeutic target.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110714"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145826799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-05DOI: 10.1016/j.abb.2025.110694
Huawei Zeng , Bryan D. Safratowich , Zhenhua Liu , Mary Briske-Anderson
High fat diets increase colonic deoxycholic acid (DCA) concentrations, which induce apoptosis, and subsequently enrich a compensatory DCA-resistant mutant colon cell subpopulation. While circadian Bmal1 and Clock genes are key regulators for cell proliferation, little is known about the relationship between DCA-induced apoptosis and circadian gene regulation in normal colon cells. In this study, we employed a noncancerous NCM460 human colon cell model to simulate the effect of DCA on cell proliferation in the colon and hypothesized that DCA-induced apoptosis is regulated by the Bmal1Clock complex in colon cells. Compared to the control cells, the treatment with DCA at 0.3- and 0.4-mM inhibited cell proliferation (via cell cycle arrest and apoptosis) by 19 % and 29 %, respectively. As the Bmal1Clock complex and Wnt signaling pathways are interlinked with apoptotic processes, we identified that 42 genes were differentially expressed in the Wnt signaling pathway; and there was a decrease (≥47 %) in Bmal1, Clock and Wee1 protein levels but an increase (≥172 %) in Rev-Erbα protein levels in DCA-treated cells compared to the control cells. At clinical levels, the mRNA levels of Bmal1 and Rev-Erbα were decreased by (≥) 15 % while Wee1 was increased by 38 % in cancerous colon tissues compared to normal ones. Collectively, DCA inhibits noncancerous NCM460 colon cell proliferation via cell cycle arrest and apoptosis accompanied with a drop of Bmal1Clock gene expression and altered Wnt signaling pathways. The Bmal1Clock regulatory network is relatively normal in the DCA-treated noncancerous NCM460 colon cells but not in colon cancer tissues.
{"title":"Microbial metabolite deoxycholic acid inhibits noncancerous NCM460 human colon cell proliferation: an inverse correlation between Bmal1:Clock gene expression and cell apoptosis","authors":"Huawei Zeng , Bryan D. Safratowich , Zhenhua Liu , Mary Briske-Anderson","doi":"10.1016/j.abb.2025.110694","DOIUrl":"10.1016/j.abb.2025.110694","url":null,"abstract":"<div><div>High fat diets increase colonic deoxycholic acid (DCA) concentrations, which induce apoptosis, and subsequently enrich a compensatory DCA-resistant mutant colon cell subpopulation. While circadian Bmal1 and Clock genes are key regulators for cell proliferation, little is known about the relationship between DCA-induced apoptosis and circadian gene regulation in normal colon cells. In this study, we employed a noncancerous NCM460 human colon cell model to simulate the effect of DCA on cell proliferation in the colon and hypothesized that DCA-induced apoptosis is regulated by the Bmal1Clock complex in colon cells. Compared to the control cells, the treatment with DCA at 0.3- and 0.4-mM inhibited cell proliferation (via cell cycle arrest and apoptosis) by 19 % and 29 %, respectively. As the Bmal1Clock complex and Wnt signaling pathways are interlinked with apoptotic processes, we identified that 42 genes were differentially expressed in the Wnt signaling pathway; and there was a decrease (≥47 %) in Bmal1, Clock and Wee1 protein levels but an increase (≥172 %) in Rev-Erbα protein levels in DCA-treated cells compared to the control cells. At clinical levels, the mRNA levels of Bmal1 and Rev-Erbα were decreased by (≥) 15 % while Wee1 was increased by 38 % in cancerous colon tissues compared to normal ones. Collectively, DCA inhibits noncancerous NCM460 colon cell proliferation via cell cycle arrest and apoptosis accompanied with a drop of Bmal1Clock gene expression and altered Wnt signaling pathways. The Bmal1Clock regulatory network is relatively normal in the DCA-treated noncancerous NCM460 colon cells but not in colon cancer tissues.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110694"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145699396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-11DOI: 10.1016/j.abb.2025.110703
Conghui Guan , Ruilin Han , Lijuan Liu , Jinjin Liu , Songbo Fu , Xulei Tang
Background
The exploration of multi-mechanism therapeutics may represent a key strategy for treating obesity and metabolic dysfunction-associated steatotic liver disease. Hydroxytyrosol (HT), a phenolic compound derived from olive oil in the Mediterranean diet, exhibits potential for obesity treatment; however, its precise mechanisms remain incompletely understood.
Objective
This study aimed to elucidate the therapeutic effects of HT in obesity and to uncover its underlying regulatory mechanisms.
Methods
An obesity model was induced in C57BL/6 mice via a high-fat diet (HFD) to evaluate the in vivo effects of HT. Assessments included glucose tolerance test (GTT), insulin tolerance test (ITT) and biochemical analyses of fasting blood glucose (FBG), fasting serum insulin (FINS), uric acid (UA), blood lipid, aspartate aminotransferase (AST), and alanine aminotransferase (ALT). Hepatic, skeletal muscle, myocardial and adipose tissue (AT) morphology were examined via H&E staining. In vitro, 3T3-L1 preadipocytes were used to investigate the effects of HT on adipogenesis and thermogenic capacity. Lipid accumulation was assessed by Oil Red O and BODIPY 493/503 staining. Protein expression levels were determined via immunohistochemistry and Western blot analysis.
Results
HFD feeding led to increased body weight, FBG, FINS, UA, AST, ALT, and the area under the curve (AUC) for GTT and ITT. H&E staining revealed hepatic vacuolization, skeletal muscle fiber hypertrophy, and myocardial disorganization in HFD-fed mice. HT treatment significantly reduced body weight, improved glucose homeostasis, lipid metabolism, and liver function, and restored normal tissue morphology of liver, skeletal muscle, myocardium, and AT. HFD upregulated the expression of PPARγ, C/EBPβ, FABP4, STING1, and NLRP3 proteins in white AT, which were markedly attenuated by HT. HT reversed HFD-induced downregulation of PGC1α and UCP1 in brown AT. In vitro experiments confirmed that HT modulates adipogenesis and thermogenic activation in preadipocyte via the STING1/NLRP3 pathways.
Conclusion
These findings demonstrate that HT acts as a novel anti-obesity agent by targeting the STING1/NLRP3 axis to suppress adipogenesis in adipose tissue and ameliorate obesity-related alterations in AT, liver, skeletal muscle, and myocardium. This study provides a mechanistic foundation for the potential application of HT in obesity intervention.
背景：探索多机制治疗可能是治疗肥胖和代谢功能障碍相关脂肪变性肝病的关键策略。羟基酪醇（HT）是一种从地中海饮食中的橄榄油中提取的酚类化合物，具有治疗肥胖的潜力；然而，它的确切机制仍然不完全清楚。目的：本研究旨在阐明激素对肥胖的治疗作用，并揭示其潜在的调节机制。方法：采用高脂饮食（HFD）诱导C57BL/6小鼠肥胖模型，评价HT的体内效应。评估包括葡萄糖耐量试验（GTT）、胰岛素耐量试验（ITT）和空腹血糖（FBG）、空腹血清胰岛素（FINS）、尿酸（UA）、血脂、天冬氨酸转氨酶（AST）、丙氨酸转氨酶（ALT）生化分析。H&E染色观察大鼠肝脏、骨骼肌、心肌和脂肪组织（AT）形态。体外实验采用3T3-L1前脂肪细胞研究HT对脂肪生成和产热能力的影响。通过Oil Red O和BODIPY 493/503染色评估脂质积累。通过免疫组织化学和western blot分析检测蛋白表达水平。结果：高脂肪饲喂导致大鼠体重、FBG、FINS、UA、AST、ALT和GTT、ITT曲线下面积（AUC）增加。H&E染色显示hfd喂养小鼠肝脏空泡化，骨骼肌纤维肥大，心肌组织紊乱。HT治疗显著降低了体重，改善了葡萄糖稳态、脂质代谢和肝功能，恢复了肝脏、骨骼肌、心肌和AT的正常组织形态。HFD上调白色AT中PPARγ、C/EBPβ、FABP4、STING1和NLRP3蛋白的表达，而这些蛋白被HT显著减弱。高温可逆转hfd诱导的褐色AT中PGC1α和UCP1的下调。体外实验证实，激素通过STING1/NLRP3通路调节前脂肪细胞的脂肪形成和产热激活。结论：这些研究结果表明，HT作为一种新型的抗肥胖药物，通过靶向STING1/NLRP3轴抑制脂肪组织的脂肪生成，改善AT、肝脏、骨骼肌和心肌中与肥胖相关的改变。本研究为HT在肥胖干预中的潜在应用提供了机制基础。
{"title":"Exploring the multiple mechanisms of Hydroxytyrosol in treating obesity","authors":"Conghui Guan , Ruilin Han , Lijuan Liu , Jinjin Liu , Songbo Fu , Xulei Tang","doi":"10.1016/j.abb.2025.110703","DOIUrl":"10.1016/j.abb.2025.110703","url":null,"abstract":"<div><h3>Background</h3><div>The exploration of multi-mechanism therapeutics may represent a key strategy for treating obesity and metabolic dysfunction-associated steatotic liver disease. Hydroxytyrosol (HT), a phenolic compound derived from olive oil in the Mediterranean diet, exhibits potential for obesity treatment; however, its precise mechanisms remain incompletely understood.</div></div><div><h3>Objective</h3><div>This study aimed to elucidate the therapeutic effects of HT in obesity and to uncover its underlying regulatory mechanisms.</div></div><div><h3>Methods</h3><div>An obesity model was induced in C57BL/6 mice via a high-fat diet (HFD) to evaluate the in vivo effects of HT. Assessments included glucose tolerance test (GTT), insulin tolerance test (ITT) and biochemical analyses of fasting blood glucose (FBG), fasting serum insulin (FINS), uric acid (UA), blood lipid, aspartate aminotransferase (AST), and alanine aminotransferase (ALT). Hepatic, skeletal muscle, myocardial and adipose tissue (AT) morphology were examined via H&E staining. In vitro, 3T3-L1 preadipocytes were used to investigate the effects of HT on adipogenesis and thermogenic capacity. Lipid accumulation was assessed by Oil Red O and BODIPY 493/503 staining. Protein expression levels were determined via immunohistochemistry and Western blot analysis.</div></div><div><h3>Results</h3><div>HFD feeding led to increased body weight, FBG, FINS, UA, AST, ALT, and the area under the curve (AUC) for GTT and ITT. H&E staining revealed hepatic vacuolization, skeletal muscle fiber hypertrophy, and myocardial disorganization in HFD-fed mice. HT treatment significantly reduced body weight, improved glucose homeostasis, lipid metabolism, and liver function, and restored normal tissue morphology of liver, skeletal muscle, myocardium, and AT. HFD upregulated the expression of PPARγ, C/EBPβ, FABP4, STING1, and NLRP3 proteins in white AT, which were markedly attenuated by HT. HT reversed HFD-induced downregulation of PGC1α and UCP1 in brown AT. In vitro experiments confirmed that HT modulates adipogenesis and thermogenic activation in preadipocyte via the STING1/NLRP3 pathways.</div></div><div><h3>Conclusion</h3><div>These findings demonstrate that HT acts as a novel anti-obesity agent by targeting the STING1/NLRP3 axis to suppress adipogenesis in adipose tissue and ameliorate obesity-related alterations in AT, liver, skeletal muscle, and myocardium. This study provides a mechanistic foundation for the potential application of HT in obesity intervention.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110703"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145751439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-17DOI: 10.1016/j.abb.2025.110707
Gustavo Pelicoli Riboldi , Samantha J. Firth , Arnaud Baslé , Kevin J. Waldron
Copper is an essential micronutrient for bacteria, needed for important copper enzymes such as terminal respiratory oxidases. However, in excess, copper is toxic to bacteria. This toxicity is caused by its ability to bind tightly to proteins through the formation of Cu-Cys and Cu-His bonds. To control toxicity, bacteria have evolved homeostatic systems to safely handle the copper they need while efficiently sequestering and effluxing excess copper ions. We previously found that GapA, the abundant glycolytic glyceraldehyde-3-phosphate dehydrogenase enzyme in the Staphylococcus aureus cytosol, becomes associated with copper within cells cultured in medium containing excess copper. We found that this association of GapA with copper resulted in inhibition of its enzyme activity. Here, we have characterised this binding of copper ions to S. aureus GapA in vitro to determine the mechanism of copper inhibition of GapA. We found that purified recombinant GapA binds a single Cu(I) ion with high affinity. Crystallographic structural determination showed association of this copper ion with two active site residues, Cys151 and His178, known to be important for catalysis. This observation was confirmed by characterisation of mutated variants lacking these residues, which showed reduced ability to bind Cu(I) ions. Finally, we demonstrated that the cytosolic copper metallochaperone, CopZ, exhibits a tighter affinity for Cu(I) and can remove copper from GapA in vitro. Together, our data demonstrate the mechanism by which excess copper binds to the S. aureus GapA enzyme and irreversibly inhibit its activity and how the cellular homeostasis system is capable of resolving this inhibition.
{"title":"Glyceraldehyde-3-phosphate dehydrogenase is inhibited by binding of Cu(I) to the essential active site cysteine","authors":"Gustavo Pelicoli Riboldi , Samantha J. Firth , Arnaud Baslé , Kevin J. Waldron","doi":"10.1016/j.abb.2025.110707","DOIUrl":"10.1016/j.abb.2025.110707","url":null,"abstract":"<div><div>Copper is an essential micronutrient for bacteria, needed for important copper enzymes such as terminal respiratory oxidases. However, in excess, copper is toxic to bacteria. This toxicity is caused by its ability to bind tightly to proteins through the formation of Cu-Cys and Cu-His bonds. To control toxicity, bacteria have evolved homeostatic systems to safely handle the copper they need while efficiently sequestering and effluxing excess copper ions. We previously found that GapA, the abundant glycolytic glyceraldehyde-3-phosphate dehydrogenase enzyme in the <em>Staphylococcus aureus</em> cytosol, becomes associated with copper within cells cultured in medium containing excess copper. We found that this association of GapA with copper resulted in inhibition of its enzyme activity. Here, we have characterised this binding of copper ions to <em>S. aureus</em> GapA <em>in vitro</em> to determine the mechanism of copper inhibition of GapA. We found that purified recombinant GapA binds a single Cu(I) ion with high affinity. Crystallographic structural determination showed association of this copper ion with two active site residues, Cys151 and His178, known to be important for catalysis. This observation was confirmed by characterisation of mutated variants lacking these residues, which showed reduced ability to bind Cu(I) ions. Finally, we demonstrated that the cytosolic copper metallochaperone, CopZ, exhibits a tighter affinity for Cu(I) and can remove copper from GapA <em>in vitro</em>. Together, our data demonstrate the mechanism by which excess copper binds to the <em>S. aureus</em> GapA enzyme and irreversibly inhibit its activity and how the cellular homeostasis system is capable of resolving this inhibition.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110707"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145793148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-24DOI: 10.1016/j.abb.2025.110715
Brittnee Cagle-White , Shrijan Bhattarai , Allison Sunderhaus , Emerald Scott , Araceli Solis , Lane Marsh , Kristina L. Catague , Aurijit Sarkar , May H. Abdel Aziz
Staphylococcus aureus (S. aureus) is a highly pathogenic bacterium that utilizes the VraSR two-component system to regulate cell wall synthesis and facilitate resistance against antibiotics. Resistant S. aureus isolates were shown to harbor several single-nucleotide polymorphisms in VraS; however, their effect on VraS functionality is not clear. We have investigated the effect of seven mutations in the VraS intracellular domain reported in clinically resistant strains on autophosphorylation rate, stability, and VraS–VraR equilibrium binding affinity (KD). The expression of wild-type VraS and mutants was optimized, and the proteins were purified using affinity chromatography. A coupled kinase assay was used to assess the autophosphorylation kinetic constants. The stability of the purified proteins was assessed using differential scanning fluorimetry, and surface plasmon resonance was used to measure the KD of the constructs to VraR. The results show that several mutations enhanced the catalytic efficiency of VraS and led to an increase in protein stability. All the mutants retained the same affinity to VraR as the wild type, except D242G, which showed a 17-fold decrease in affinity. Molecular dynamics simulation of a generated dimeric VraS homology model shows that the M192I mutant may have an increased possibility of forming the Michaelis complex. This study investigated the effect of VraS mutations on the enzymatic activity, stability, and affinity to its cognate response regulator, which can translate to a modified bacterial response to stress. The results highlight the importance of studying bacterial kinase mutations as an underlying mechanism of antibiotic resistance in S. aureus.
{"title":"Staphylococcus aureus sensor histidine kinase VraS mutations linked to antibiotic resistance affect enzymatic catalysis, stability, and substrate interactions","authors":"Brittnee Cagle-White , Shrijan Bhattarai , Allison Sunderhaus , Emerald Scott , Araceli Solis , Lane Marsh , Kristina L. Catague , Aurijit Sarkar , May H. Abdel Aziz","doi":"10.1016/j.abb.2025.110715","DOIUrl":"10.1016/j.abb.2025.110715","url":null,"abstract":"<div><div><em>Staphylococcus aureus</em> (<em>S. aureus</em>) is a highly pathogenic bacterium that utilizes the VraSR two-component system to regulate cell wall synthesis and facilitate resistance against antibiotics. Resistant <em>S. aureus</em> isolates were shown to harbor several single-nucleotide polymorphisms in VraS; however, their effect on VraS functionality is not clear. We have investigated the effect of seven mutations in the VraS intracellular domain reported in clinically resistant strains on autophosphorylation rate, stability, and VraS–VraR equilibrium binding affinity (K<sub>D</sub>). The expression of wild-type VraS and mutants was optimized, and the proteins were purified using affinity chromatography. A coupled kinase assay was used to assess the autophosphorylation kinetic constants. The stability of the purified proteins was assessed using differential scanning fluorimetry, and surface plasmon resonance was used to measure the K<sub>D</sub> of the constructs to VraR. The results show that several mutations enhanced the catalytic efficiency of VraS and led to an increase in protein stability. All the mutants retained the same affinity to VraR as the wild type, except D242G, which showed a 17-fold decrease in affinity. Molecular dynamics simulation of a generated dimeric VraS homology model shows that the M192I mutant may have an increased possibility of forming the Michaelis complex. This study investigated the effect of VraS mutations on the enzymatic activity, stability, and affinity to its cognate response regulator, which can translate to a modified bacterial response to stress. The results highlight the importance of studying bacterial kinase mutations as an underlying mechanism of antibiotic resistance in <em>S. aureus.</em></div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110715"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-03DOI: 10.1016/j.abb.2025.110691
Tai Dou , Lijie Qin , Peirong Zhang, Lijun Xu, Yanwei Cheng, Peng Wang
Aims
To investigate the expression characteristics, clinical implications, and underlying mechanisms of miR-491-3p in patients with acute myocardial infarction (AMI).
Methods
Serum samples were collected from patients with AMI and healthy controls. miR-491-3p expression was measured using reverse transcription quantitative polymerase chain reaction (RT-qPCR). Receiver operating characteristic (ROC) curves evaluated its diagnostic accuracy for AMI. Correlations between miR-491-3p levels and myocardial injury markers or inflammatory factors were analyzed. A one-year follow-up assessed its predictive value for major adverse cardiovascular events (MACE). A hypoxia/reoxygenation (H/R) model of human AC16 cardiomyocytes was established to explore the mechanism of miR-491-3p in H/R-induced injury via targeting aquaporin 9 (AQP9).
Results
Serum miR-491-3p was significantly downregulated in AMI patients, with an AUC of 0.893 for AMI diagnosis (sensitivity 83 %, specificity 79.5 %). Levels were negatively correlated with myocardial injury markers and inflammatory factors. AMI patients with low miR-491-3p expression had a higher incidence of MACE, and low expression was identified as a risk factor. In the H/R model, miR-491-3p was downregulated. Overexpression of miR-491-3p improved cell proliferation, reduced apoptosis, and decreased inflammatory factors by targeting and inhibiting AQP9.
Conclusions
miR-491-3p may be involved in the pathological process of AMI by targeting and regulating AQP9. This makes it a promising candidate as both a diagnostic and prognostic marker for AMI, as well as a potential therapeutic target.
{"title":"The role of miR-491-3p in early diagnosis and prognosis evaluation of acute myocardial infarction","authors":"Tai Dou , Lijie Qin , Peirong Zhang, Lijun Xu, Yanwei Cheng, Peng Wang","doi":"10.1016/j.abb.2025.110691","DOIUrl":"10.1016/j.abb.2025.110691","url":null,"abstract":"<div><h3>Aims</h3><div>To investigate the expression characteristics, clinical implications, and underlying mechanisms of miR-491-3p in patients with acute myocardial infarction (AMI).</div></div><div><h3>Methods</h3><div>Serum samples were collected from patients with AMI and healthy controls. miR-491-3p expression was measured using reverse transcription quantitative polymerase chain reaction (RT-qPCR). Receiver operating characteristic (ROC) curves evaluated its diagnostic accuracy for AMI. Correlations between miR-491-3p levels and myocardial injury markers or inflammatory factors were analyzed. A one-year follow-up assessed its predictive value for major adverse cardiovascular events (MACE). A hypoxia/reoxygenation (H/R) model of human AC16 cardiomyocytes was established to explore the mechanism of miR-491-3p in H/R-induced injury via targeting aquaporin 9 (AQP9).</div></div><div><h3>Results</h3><div>Serum miR-491-3p was significantly downregulated in AMI patients, with an AUC of 0.893 for AMI diagnosis (sensitivity 83 %, specificity 79.5 %). Levels were negatively correlated with myocardial injury markers and inflammatory factors. AMI patients with low miR-491-3p expression had a higher incidence of MACE, and low expression was identified as a risk factor. In the H/R model, miR-491-3p was downregulated. Overexpression of miR-491-3p improved cell proliferation, reduced apoptosis, and decreased inflammatory factors by targeting and inhibiting AQP9.</div></div><div><h3>Conclusions</h3><div>miR-491-3p may be involved in the pathological process of AMI by targeting and regulating AQP9. This makes it a promising candidate as both a diagnostic and prognostic marker for AMI, as well as a potential therapeutic target.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"776 ","pages":"Article 110691"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145686944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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