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Maeda K, Yamada H, Munetsuna E, Fujii R, Yamazaki M, Ando Y, Mizuno G, Tsuboi Y, Ishikawa H, Ohashi K, Hashimoto S, Hamajima N, Suzuki K. Serum carotenoid levels are positively associated with DNA methylation of thioredoxin-interacting protein. INT J VITAM NUTR RES 2024; 94:210-220. [PMID: 37735933 DOI: 10.1024/0300-9831/a000791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
Background: Carotenoids have been reported to exert protective effects against age-related diseases via changes in DNA methylation. Although lower thioredoxin-interacting protein (TXNIP) DNA methylation is associated with age-related diseases, only a few studies have investigated the factors influencing TXNIP DNA methylation. Carotenoids may be a factor linking TXNIP to specific pathophysiological functions. The aim of this study was to examine whether serum carotenoid levels are associated with TXNIP DNA methylation levels. Methods: We conducted a cross-sectional study using 376 health examination participants (169 men). DNA methylation levels were determined using a pyrosequencing assay. Serum carotenoid levels were determined by high-performance liquid chromatography. Multivariable regression analyses were performed to examine the associations between TXNIP DNA methylation levels and serum carotenoid levels with adjustment for age, BMI, HbA1c, CRP, smoking habits, alcohol consumption, exercise habits, and percentage of neutrophils. Results: Multiple linear regression analyses showed that TXNIP DNA methylation levels were positively associated with serum levels of zeaxanthin/lutein (β [95%CI]: 1.935 [0.184, 3.685]), β-cryptoxanthin (1.447 [0.324, 2.570]), α-carotene (1.061 [0.044, 2.077]), β-carotene (1.272 [0.319, 2.226]), total carotenes (1.255 [0.040, 2.469]), total xanthophylls (2.133 [0.315, 3.951]), provitamin A (1.460 [0.402, 2.519]), and total carotenoids (1.972 [0.261, 3.683]) in men (all p<0.05). Of these, provitamin A showed the stronger association (standardized β=0.216). No significant association of TXNIP DNA methylation and serum carotenoid was observed in women. Conclusions: The findings of this study suggest that carotenoid intake may protect against age-related diseases by altering TXNIP DNA methylation status in men.
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Affiliation(s)
- Keisuke Maeda
- Department of Clinical Physiology, Fujita Health University School of Medical Sciences, Toyoake, Japan
| | - Hiroya Yamada
- Department of Hygiene, Fujita Health University School of Medicine, Toyoake, Japan
| | - Eiji Munetsuna
- Department of Biochemistry, Fujita Health University School of Medicine, Toyoake, Japan
| | - Ryosuke Fujii
- Department of Preventive Medical Sciences, Fujita Health University School of Medical Sciences, Toyoake, Japan
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Bolzano/Bozen, Italy
| | - Mirai Yamazaki
- Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Takamatsu, Japan
| | - Yoshitaka Ando
- Department of Informative Clinical Medicine, Fujita Health University School of Medical Sciences, Toyoake, Japan
| | - Genki Mizuno
- Department of Medical Technology, School of Health Sciences, Tokyo University of Technology, Tokyo, Japan
| | - Yoshiki Tsuboi
- Department of Preventive Medical Sciences, Fujita Health University School of Medical Sciences, Toyoake, Japan
| | - Hiroaki Ishikawa
- Department of Informative Clinical Medicine, Fujita Health University School of Medical Sciences, Toyoake, Japan
| | - Koji Ohashi
- Department of Informative Clinical Medicine, Fujita Health University School of Medical Sciences, Toyoake, Japan
| | - Shuji Hashimoto
- Department of Hygiene, Fujita Health University School of Medicine, Toyoake, Japan
| | - Nobuyuki Hamajima
- Department of Healthcare Administration, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Koji Suzuki
- Department of Preventive Medical Sciences, Fujita Health University School of Medical Sciences, Toyoake, Japan
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2
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Deng J, Pan T, Liu Z, McCarthy C, Vicencio JM, Cao L, Alfano G, Suwaidan AA, Yin M, Beatson R, Ng T. The role of TXNIP in cancer: a fine balance between redox, metabolic, and immunological tumor control. Br J Cancer 2023; 129:1877-1892. [PMID: 37794178 PMCID: PMC10703902 DOI: 10.1038/s41416-023-02442-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 09/07/2023] [Accepted: 09/14/2023] [Indexed: 10/06/2023] Open
Abstract
Thioredoxin-interacting protein (TXNIP) is commonly considered a master regulator of cellular oxidation, regulating the expression and function of Thioredoxin (Trx). Recent work has identified that TXNIP has a far wider range of additional roles: from regulating glucose and lipid metabolism, to cell cycle arrest and inflammation. Its expression is increased by stressors commonly found in neoplastic cells and the wider tumor microenvironment (TME), and, as such, TXNIP has been extensively studied in cancers. In this review, we evaluate the current literature regarding the regulation and the function of TXNIP, highlighting its emerging role in modulating signaling between different cell types within the TME. We then assess current and future translational opportunities and the associated challenges in this area. An improved understanding of the functions and mechanisms of TXNIP in cancers may enhance its suitability as a therapeutic target.
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Affiliation(s)
- Jinhai Deng
- Richard Dimbleby Laboratory of Cancer Research, School of Cancer & Pharmaceutical Sciences, King's College London, London, UK
- Clinical Research Center (CRC), Clinical Pathology Center (CPC), Chongqing University Three Gorges Hospital, Chongqing University, Wanzhou, Chongqing, China
| | - Teng Pan
- Longgang District Maternity & Child Healthcare Hospital of Shenzhen City (Longgang Maternity and Child Institute of Shantou University Medical College), Shenzhen, 518172, China
| | - Zaoqu Liu
- Department of Interventional Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Caitlin McCarthy
- Richard Dimbleby Laboratory of Cancer Research, School of Cancer & Pharmaceutical Sciences, King's College London, London, UK
| | - Jose M Vicencio
- Richard Dimbleby Laboratory of Cancer Research, School of Cancer & Pharmaceutical Sciences, King's College London, London, UK
| | - Lulu Cao
- Department of Rheumatology and Immunology, Peking University People's Hospital and Beijing Key Laboratory for Rheumatism Mechanism and Immune Diagnosis (BZ0135), Beijing, China
| | - Giovanna Alfano
- Richard Dimbleby Laboratory of Cancer Research, School of Cancer & Pharmaceutical Sciences, King's College London, London, UK
| | - Ali Abdulnabi Suwaidan
- Richard Dimbleby Laboratory of Cancer Research, School of Cancer & Pharmaceutical Sciences, King's College London, London, UK
| | - Mingzhu Yin
- Clinical Research Center (CRC), Clinical Pathology Center (CPC), Chongqing University Three Gorges Hospital, Chongqing University, Wanzhou, Chongqing, China
| | - Richard Beatson
- Richard Dimbleby Laboratory of Cancer Research, School of Cancer & Pharmaceutical Sciences, King's College London, London, UK.
- Centre for Inflammation and Tissue Repair, UCL Respiratory, Division of Medicine, University College London (UCL), Rayne 9 Building, London, WC1E 6JF, UK.
| | - Tony Ng
- Richard Dimbleby Laboratory of Cancer Research, School of Cancer & Pharmaceutical Sciences, King's College London, London, UK.
- UCL Cancer Institute, University College London, London, UK.
- Cancer Research UK City of London Centre, London, UK.
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3
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Singh J, Sah B, Shen Y, Liu L. Histone methyltransferase inhibitor UNC0642 promotes breast cancer cell death by upregulating TXNIP-dependent oxidative stress. Chem Biol Interact 2023; 385:110720. [PMID: 37748637 DOI: 10.1016/j.cbi.2023.110720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/04/2023] [Accepted: 09/18/2023] [Indexed: 09/27/2023]
Abstract
Breast cancer (BC) is one of the most frequent type of cancer in women worldwide. Current therapeutic strategies for BC are not always effective. In this study, we investigated the anticancer activity of an epigenetic compound UNC0642 and its mechanism of action in suppressing BC cell growth and survival. UNC0642 was developed as a selective inhibitor of G9a that is responsible for histone H3K9 methylation. After screening different BC cell lines, we found UNC0642 had the lowest IC-50 against MDA-MB-231 cells, a triple-negative BC cell line. To identify additional UNC0642 targets, we performed RNA-seq analyses in BC cells following UNC0642 treatment. UNC0642 significantly upregulated mRNA expression of thioredoxin-interacting protein (TXNIP), which was also validated by western blotting. We further showed that TXNIP upregulation was associated with dose-dependent elevation of reactive oxygen species, concurrent with loss of mitochondrial membrane potential and activation of caspase-3-dependent apoptosis. Finally, we demonstrated that UNC0642 treatment induced BC cell apoptosis in vitro and suppression of tumor growth in xenograft mouse models that was coupled with TXNIP activation. Taken together, our results show that UNC0642 exerts its antitumor function via upregulating TXNIP expression and oxidative stress to impair mitochondrial function and induce caspase-dependent cell death. This observation could inform future breast cancer therapies by targeting TXNIP-dependent ROS signaling.
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Affiliation(s)
- Jasvinder Singh
- The Hormel Institute, University of Minnesota, Austin, MN, 55912, USA.
| | - Bindeshwar Sah
- The Hormel Institute, University of Minnesota, Austin, MN, 55912, USA
| | - Yao Shen
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Liang Liu
- The Hormel Institute, University of Minnesota, Austin, MN, 55912, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, 55455, USA
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4
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Lim TY, Wilde BR, Thomas ML, Murphy KE, Vahrenkamp JM, Conway ME, Varley KE, Gertz J, Ayer DE. TXNIP loss expands Myc-dependent transcriptional programs by increasing Myc genomic binding. PLoS Biol 2023; 21:e3001778. [PMID: 36930677 PMCID: PMC10058090 DOI: 10.1371/journal.pbio.3001778] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 03/29/2023] [Accepted: 02/13/2023] [Indexed: 03/18/2023] Open
Abstract
The c-Myc protooncogene places a demand on glucose uptake to drive glucose-dependent biosynthetic pathways. To meet this demand, c-Myc protein (Myc henceforth) drives the expression of glucose transporters, glycolytic enzymes, and represses the expression of thioredoxin interacting protein (TXNIP), which is a potent negative regulator of glucose uptake. A Mychigh/TXNIPlow gene signature is clinically significant as it correlates with poor clinical prognosis in triple-negative breast cancer (TNBC) but not in other subtypes of breast cancer, suggesting a functional relationship between Myc and TXNIP. To better understand how TXNIP contributes to the aggressive behavior of TNBC, we generated TXNIP null MDA-MB-231 (231:TKO) cells for our study. We show that TXNIP loss drives a transcriptional program that resembles those driven by Myc and increases global Myc genome occupancy. TXNIP loss allows Myc to invade the promoters and enhancers of target genes that are potentially relevant to cell transformation. Together, these findings suggest that TXNIP is a broad repressor of Myc genomic binding. The increase in Myc genomic binding in the 231:TKO cells expands the Myc-dependent transcriptome we identified in parental MDA-MB-231 cells. This expansion of Myc-dependent transcription following TXNIP loss occurs without an apparent increase in Myc's intrinsic capacity to activate transcription and without increasing Myc levels. Together, our findings suggest that TXNIP loss mimics Myc overexpression, connecting Myc genomic binding and transcriptional programs to the nutrient and progrowth signals that control TXNIP expression.
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Affiliation(s)
- Tian-Yeh Lim
- Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
| | - Blake R Wilde
- Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
| | - Mallory L Thomas
- Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
| | - Kristin E Murphy
- Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
| | - Jeffery M Vahrenkamp
- Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
| | - Megan E Conway
- Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
| | - Katherine E Varley
- Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
| | - Jason Gertz
- Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
| | - Donald E Ayer
- Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
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5
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Hukkamlı B, Dağdelen B, Sönmez Aydın F, Budak H. Comparison of the efficacy of the mouse hepatic and renal antioxidant systems against inflammation-induced oxidative stress. Cell Biochem Biophys 2023:10.1007/s12013-023-01126-3. [PMID: 36773183 DOI: 10.1007/s12013-023-01126-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2023] [Indexed: 02/12/2023]
Abstract
This study was conducted to compare the efficacy of the mouse hepatic and renal antioxidant systems against inflammation-induced oxidative stress. Increased Il-1 and Il-6 expressions, markers of inflammation, were represented by inflammation models in mouse liver and kidney tissues injected intraperitoneally with LPS. After establishing the model, the GSH level and the GSH/GSSG ratio, which are oxidative stress markers, were investigated in both tissues treated with LPS and the control group. The expression of Trx1, TrxR, and Txnip genes increased in the liver tissues of LPS-treated mice. In the kidney tissue, while Trx1 expression decreased, no change was observed in TrxR1 expression, and Txnip expression increased. In the kidneys, TRXR1 and GR activities decreased, whereas GPx activity increased. In both tissues, the TRXR1 protein expression decreased significantly, while TXNIP expression increased. In conclusion, different behaviors of antioxidant system members were observed during acute inflammation in both tissues. Additionally, it can be said that the kidney tissue is more sensitive and takes earlier measures than the liver tissue against cellular damage caused by inflammation and inflammation-induced oxidative stress.
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Affiliation(s)
- Berna Hukkamlı
- Department of Molecular Biology and Genetics, Science Faculty, Atatürk University, Erzurum, 25240, Türkiye
- Department of Chemical and Chemical Processing Technologies, Boyabat Vocational School, Sinop University, Sinop, 57200, Türkiye
| | - Burak Dağdelen
- Department of Medical Biology, Faculty of Medicine, Selçuk University, Konya, 42250, Türkiye
| | - Feyza Sönmez Aydın
- Department of Molecular Biology and Genetics, Science Faculty, Atatürk University, Erzurum, 25240, Türkiye
- Department of Pathology Laboratory Techniques, Vocational School, Doğuş University, Istanbul, 34775, Türkiye
| | - Harun Budak
- Department of Molecular Biology and Genetics, Science Faculty, Atatürk University, Erzurum, 25240, Türkiye.
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6
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Wang Y, Liu J, Liu H, Sun X, Chen R, Liao B, Zeng X, Zhang X, Dong S, Xia Z, Yuan J. Slow flow induces endothelial dysfunction by regulating thioredoxin-interacting protein-mediated oxidative metabolism and vascular inflammation. Front Cardiovasc Med 2022; 9:1064375. [PMID: 36465470 PMCID: PMC9708747 DOI: 10.3389/fcvm.2022.1064375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 10/25/2022] [Indexed: 08/30/2023] Open
Abstract
Endothelial cells are highly sensitive to hemodynamic shear stresses, which act in the blood flow's direction on the blood vessel's luminal surface. Thus, endothelial cells on that surface are exposed to various physiological and pathological stimuli, such as disturbed flow-induced shear stress, which may exert effects on adaptive vascular diameter or structural wall remodeling. Here we showed that plasma thioredoxin-interactive protein (TXNIP) and malondialdehyde levels were significantly increased in patients with slow coronary flow. In addition, human endothelial cells exposed to disturbed flow exhibited increased levels of TXNIP in vitro. On the other hand, deletion of human endothelial TXNIP increased capillary formation, nitric oxide production and mitochondrial function, as well as lessened oxidative stress response and endothelial cell inflammation. Additional beneficial impacts from TXNIP deletion were also seen in a glucose utilization study, as reflected by augmented glucose uptake, lactate secretion and extracellular acidification rate. Taken together, our results suggested that TXNIP is a key component involved in mediating shear stress-induced inflammation, energy homeostasis, and glucose utilization, and that TXNIP may serve as a potentially novel endothelial dysfunction regulator.
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Affiliation(s)
- Yongshun Wang
- Department of Cardiology, Shenzhen People’s Hospital, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Jingjin Liu
- Department of Cardiology, Shenzhen People’s Hospital, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Huadong Liu
- Department of Cardiology, Shenzhen People’s Hospital, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Xin Sun
- Department of Cardiology, Shenzhen People’s Hospital, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Ruimian Chen
- Department of Cardiology, Shenzhen People’s Hospital, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Bihong Liao
- Department of Cardiology, Shenzhen People’s Hospital, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Xiaoyi Zeng
- Department of Cardiology, Shenzhen People’s Hospital, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Xiaoxin Zhang
- Department of Cardiology, Shenzhen People’s Hospital, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Shaohong Dong
- Department of Cardiology, Shenzhen People’s Hospital, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Zhengyuan Xia
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Jie Yuan
- Department of Cardiology, Shenzhen People’s Hospital, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College, Jinan University, Shenzhen, China
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7
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Lu B, Chen J, Xu G, Grayson TB, Jing G, Jo S, Shalev A. Alpha Cell Thioredoxin-interacting Protein Deletion Improves Diabetes-associated Hyperglycemia and Hyperglucagonemia. Endocrinology 2022; 163:bqac133. [PMID: 35957590 PMCID: PMC10233251 DOI: 10.1210/endocr/bqac133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Indexed: 11/19/2022]
Abstract
Thioredoxin-interacting protein (TXNIP) has emerged as a key factor in pancreatic beta cell biology, and its upregulation by glucose and diabetes contributes to the impairment in functional beta cell mass and glucose homeostasis. In addition, beta cell deletion of TXNIP protects against diabetes in different mouse models. However, while TXNIP is ubiquitously expressed, its role in pancreatic alpha cells has remained elusive. We generated an alpha cell TXNIP knockout (aTKO) mouse and assessed the effects on glucose homeostasis. While no significant changes were observed on regular chow, after a 30-week high-fat diet, aTKO animals showed improvement in glucose tolerance and lower blood glucose levels compared to their control littermates. Moreover, in the context of streptozotocin (STZ)-induced diabetes, aTKO mice showed significantly lower blood glucose levels compared to controls. While serum insulin levels were reduced in both control and aTKO mice, STZ-induced diabetes significantly increased glucagon levels in control mice, but this effect was blunted in aTKO mice. Moreover, glucagon secretion from aTKO islets was >2-fold lower than from control islets, while insulin secretion was unchanged in aTKO islets. At the same time, no change in alpha cell or beta cell numbers or mass was observed, and glucagon and insulin expression and content were comparable in isolated islets from aTKO and control mice. Thus together the current studies suggest that downregulation of alpha cell TXNIP is associated with reduced glucagon secretion and that this may contribute to the glucose-lowering effects observed in diabetic aTKO mice.
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Affiliation(s)
- Brian Lu
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Junqin Chen
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Guanlan Xu
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Truman B Grayson
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Gu Jing
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - SeongHo Jo
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Anath Shalev
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
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8
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Endothelial thioredoxin interacting protein (TXNIP) modulates endothelium-dependent vasorelaxation in hyperglycemia. Microvasc Res 2022; 143:104396. [PMID: 35644243 DOI: 10.1016/j.mvr.2022.104396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 11/24/2022]
Abstract
Endothelial dysfunction, hallmarked by an imbalance between vasoconstriction and vasorelaxation, is associated with diabetes. Thioredoxin Interacting protein (TXNIP), controlled by an exquisitely glucose sensitive gene, is increasingly recognized for its role in diabetes. However, the role of TXNIP in modulating diabetes-related endothelial dysfunction remains unclear. To elucidate the role of TXNIP, we generated two novel mouse strains; endothelial-specific TXNIP knockout (EKO) and a Tet-O inducible, endothelial-specific TXNIP overexpression (EKI). Hyperglycemia was induced by streptozotocin (STZ) treatment in floxed control (fl/fl) and EKO mice. Doxycycline (DOX) was given to EKI mice to induce endothelial TXNIP overexpression. The ablation of endothelial TXNIP improved glucose tolerance in EKO mice. Acetylcholine-induced, endothelium-dependent vasorelaxation was impaired in STZ-treated fl/fl mice while this STZ impaired vasorelaxation was attenuated in EKO mice. Hyperglycemia induction of NLRP3 and reductions in Akt and eNOS phosphorylation were also mitigated in EKO mice. Overexpression of endothelial TXNIP did not impair glucose tolerance in DOX-treated EKI mice, however induction of endothelial TXNIP led to impaired vasorelaxation in EKI mice. This was associated with increased NLRP3 and reduced Akt and eNOS activation. In conclusion, deletion of endothelial TXNIP is protective against and overexpression of endothelial TXNIP induces endothelial dysfunction; thus, endothelial TXNIP plays a critical role in modulating endothelial dysfunction.
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Abstract
Significance: Thioredoxin-interacting protein (Txnip) is an α-arrestin protein that acts as a cancer suppressor. Txnip is simultaneously a critical regulator of energy metabolism. Other alpha-arrestin proteins also play key roles in cell biology and cancer. Recent Advances: Txnip expression is regulated by multilayered mechanisms, including transcriptional regulation, microRNA, messenger RNA (mRNA) stabilization, and protein degradation. The Txnip-based connection between cancer and metabolism has been widely recognized. Meanwhile, new aspects are proposed for the mechanism of action of Txnip, including the regulation of RNA expression and autophagy. Arrestin domain containing 3 (ARRDC3), another α-arrestin protein, regulates endocytosis and signaling, whereas ARRDC1 and ARRDC4 regulate extracellular vesicle formation. Critical Issues: The mechanism of action of Txnip is yet to be elucidated. The regulation of intracellular protein trafficking by arrestin family proteins has opened an emerging field of biology and medical research, which needs to be examined further. Future Directions: A fundamental understanding of the mechanism of action of Txnip and other arrestin family members needs to be explored in the future to combat diseases such as cancer and diabetes. Antioxid. Redox Signal. 36, 1001-1022.
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Affiliation(s)
- Hiroshi Masutani
- Department of Clinical Laboratory Sciences, Tenri Health Care University, Tenri, Japan.,Department of Infection and Prevention, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
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10
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Lei Z, Chen Y, Wang J, Zhang Y, Shi W, Wang X, Xing D, Li D, Jiao X. Txnip deficiency promotes β-cell proliferation in the HFD-induced obesity mouse model. Endocr Connect 2022; 11:EC-21-0641. [PMID: 35294398 PMCID: PMC9066588 DOI: 10.1530/ec-21-0641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 03/16/2022] [Indexed: 11/25/2022]
Abstract
Elucidating the mechanisms of regulation of β-cell proliferation is key to understanding the pathogenesis of diabetes mellitus. Txnip is a tumor suppressor that is upregulated in diabetes and plays an important role in the regulation of insulin sensitivity; however, its potential effect on pancreatic β-cell proliferation remains unclear. Here, we evaluated the role of Txnip in pancreatic β-cell compensatory proliferation by subjecting WT and Txnip knockout (KO) mice to a high-fat diet (HFD). Our results demonstrate that Txnip deficiency improves glucose tolerance and increases insulin sensitivity in HFD-induced obesity. The antidiabetogenic effect of Txnip deficiency was accompanied by increased β-cell proliferation and enhanced β-cell mass expansion. Furthermore, Txnip deficiency modulated the expression of a set of transcription factors with key roles in β-cell proliferation and cell cycle regulation. Txnip KO in HFD mice also led to activated levels of p-PI3K, p-AKT, p-mTOR and p-GSK3β, suggesting that Txnip may act via PI3K/AKT signaling to suppress β-cell proliferation. Thus, our work provides a theoretical basis for Txnip as a new therapeutic target for the treatment of diabetes mellitus.
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Affiliation(s)
- Zhandong Lei
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, China
- Department of Anatomy, Shanxi Medical University, Taiyuan, China
| | - Yunfei Chen
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, China
| | - Jin Wang
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, China
| | - Yan Zhang
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, China
| | - Wenjuan Shi
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, China
| | - Xuejiao Wang
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, China
| | - Dehai Xing
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, China
| | - Dongxue Li
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, China
| | - Xiangying Jiao
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, China
- Correspondence should be addressed to X Jiao:
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11
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Eraky SM, Ramadan NM, Abo El-Magd NF. Antidiabetic effects of quercetin and liraglutide combination through modulation of TXNIP/IRS-1/PI3K pathway. Cell Biochem Funct 2021; 40:90-102. [PMID: 34855213 DOI: 10.1002/cbf.3678] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/19/2021] [Accepted: 11/08/2021] [Indexed: 12/30/2022]
Abstract
The study was designed to assess the possible augmented antidiabetic effects of combining quercetin and liraglutide in a type 1 diabetes model, with emphasis on the contribution of hepatic thioredoxin interacting protein (TXNIP)/insulin receptor substrate 1 (IRS-1)/phosphatidyl inositol-3 kinase (PI3K) pathway. The wound-healing effects were also examined. Diabetes was induced by a single i.p STZ injection (55 mg/kg). Diabetic rats were treated with either quercetin (100 mg/kg/day, orally) or liraglutide (0.3 mg/kg/twice daily, S.C.) or their combination. Drugs were also applied topically on the wound. Blood glucose levels, serum albumin, total protein, total cholesterol and triglycerides were measured. Histopathological examination of the liver, pancreas and skin tissues was performed using haematoxylin and eosin staining. The hepatic malondialdehyde level was measured spectrophotometrically. Hepatic TXNIP and PI3K levels were measured by enzyme-linked immunsorbent assay (ELISA). Tissue expression of IRS-1 and phospho-IRS-1 (Ser 616) was assessed by immunohistochemistry. Quercetin, liraglutide and their combination effectively decreased blood glucose levels, improved lipid profile, upregulated albumin and total protein serum levels and reduced hepatic oxidative stress with the combination being most effective. Moreover, the combination group showed enhanced wound-healing effects and almost normalized hepatic and pancreatic histopathology. Quercetin and/or liraglutide significantly decreased TXNIP levels and serine phosphorylation of IRS-1 and increased PI3K levels compared to the diabetic untreated group. Interestingly, only the combination therapy normalized hepatic IRS-1 expression. The combination of quercetin and liraglutide showed enhanced antidiabetic effects, possibly through lowering hepatic TXNIP levels, with the resultant up-regulation of the IRS-1/PI3K pathway.
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Affiliation(s)
- Salma M Eraky
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Nehal M Ramadan
- Clinical Pharmacology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Nada F Abo El-Magd
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
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12
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Waldhart AN, Muhire B, Johnson B, Pettinga D, Madaj ZB, Wolfrum E, Dykstra H, Wegert V, Pospisilik JA, Han X, Wu N. Excess dietary carbohydrate affects mitochondrial integrity as observed in brown adipose tissue. Cell Rep 2021; 36:109488. [PMID: 34348139 PMCID: PMC8449951 DOI: 10.1016/j.celrep.2021.109488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 02/05/2021] [Accepted: 07/13/2021] [Indexed: 12/17/2022] Open
Abstract
Hyperglycemia affects over 400 million individuals worldwide. The detrimental health effects are well studied at the tissue level, but the in vivo effects at the organelle level are poorly understood. To establish such an in vivo model, we used mice lacking TXNIP, a negative regulator of glucose uptake. Examining mitochondrial function in brown adipose tissue, we find that TXNIP KO mice have a lower content of polyunsaturated fatty acids (PUFAs) in their membrane lipids, which affects mitochondrial integrity and electron transport chain efficiency and ultimately results in lower mitochondrial heat output. This phenotype can be rescued by a ketogenic diet, confirming the usefulness of this model and highlighting one facet of early cellular damage caused by excess glucose influx.
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Affiliation(s)
| | | | - Ben Johnson
- Van Andel Institute, Grand Rapids, MI 49503, USA
| | | | | | | | | | | | | | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, UT Health San Antonio, San Antonio, TX 78229, USA; Department of Medicine, UT Health San Antonio, San Antonio, TX 78229, USA
| | - Ning Wu
- Van Andel Institute, Grand Rapids, MI 49503, USA.
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Cao X, He W, Pang Y, Cao Y, Qin A. Redox-dependent and independent effects of thioredoxin interacting protein. Biol Chem 2021; 401:1215-1231. [PMID: 32845855 DOI: 10.1515/hsz-2020-0181] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/13/2020] [Indexed: 12/12/2022]
Abstract
Thioredoxin interacting protein (TXNIP) is an important physiological inhibitor of the thioredoxin (TXN) redox system in cells. Regulation of TXNIP expression and/or activity not only plays an important role in redox regulation but also exerts redox-independent physiological effects that exhibit direct pathophysiological consequences including elevated inflammatory response, aberrant glucose metabolism, cellular senescence and apoptosis, cellular immunity, and tumorigenesis. This review provides a brief overview of the current knowledge concerning the redox-dependent and independent roles of TXNIP and its relevance to various disease states. The implications for the therapeutic targeting of TXNIP will also be discussed.
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Affiliation(s)
- Xiankun Cao
- Department of Orthopaedic Surgery, Shanghai Key Laboratory of Orthopedic Implants, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, No. 639, Zhizaoju Road, Shanghai, 200011,People's Republic of China
| | - Wenxin He
- Department of Orthopaedic Surgery, Shanghai Key Laboratory of Orthopedic Implants, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, No. 639, Zhizaoju Road, Shanghai, 200011,People's Republic of China
| | - Yichuan Pang
- Department of Oral Surgery, Shanghai Key Laboratory of Stomatology, National Clinical Research Center of Stomatology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011,People's Republic of China
| | - Yu Cao
- Department of Orthopaedics and Institute of Precision Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, No. 639, Zhizaoju Road, Shanghai, 200011,People's Republic of China
| | - An Qin
- Department of Orthopaedic Surgery, Shanghai Key Laboratory of Orthopedic Implants, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, No. 639, Zhizaoju Road, Shanghai, 200011,People's Republic of China
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14
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Role of Thioredoxin-Interacting Protein in Diseases and Its Therapeutic Outlook. Int J Mol Sci 2021; 22:ijms22052754. [PMID: 33803178 PMCID: PMC7963165 DOI: 10.3390/ijms22052754] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/26/2021] [Accepted: 03/03/2021] [Indexed: 12/11/2022] Open
Abstract
Thioredoxin-interacting protein (TXNIP), widely known as thioredoxin-binding protein 2 (TBP2), is a major binding mediator in the thioredoxin (TXN) antioxidant system, which involves a reduction-oxidation (redox) signaling complex and is pivotal for the pathophysiology of some diseases. TXNIP increases reactive oxygen species production and oxidative stress and thereby contributes to apoptosis. Recent studies indicate an evolving role of TXNIP in the pathogenesis of complex diseases such as metabolic disorders, neurological disorders, and inflammatory illnesses. In addition, TXNIP has gained significant attention due to its wide range of functions in energy metabolism, insulin sensitivity, improved insulin secretion, and also in the regulation of glucose and tumor suppressor activities in various cancers. This review aims to highlight the roles of TXNIP in the field of diabetology, neurodegenerative diseases, and inflammation. TXNIP is found to be a promising novel therapeutic target in the current review, not only in the aforementioned diseases but also in prolonged microvascular and macrovascular diseases. Therefore, TXNIP inhibitors hold promise for preventing the growing incidence of complications in relevant diseases.
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15
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Noblet B, Benhamed F, O-Sullivan I, Zhang W, Filhoulaud G, Montagner A, Polizzi A, Marmier S, Burnol AF, Guilmeau S, Issad T, Guillou H, Bernard C, Unterman T, Postic C. Dual regulation of TxNIP by ChREBP and FoxO1 in liver. iScience 2021; 24:102218. [PMID: 33748706 PMCID: PMC7966993 DOI: 10.1016/j.isci.2021.102218] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 11/17/2020] [Accepted: 02/18/2021] [Indexed: 12/12/2022] Open
Abstract
TxNIP (Thioredoxin-interacting protein) is considered as a potential drug target for type 2 diabetes. Although TxNIP expression is correlated with hyperglycemia and glucotoxicity in pancreatic β cells, its regulation in liver cells has been less investigated. In the current study, we aim at providing a better understanding of Txnip regulation in hepatocytes in response to physiological stimuli and in the context of hyperglycemia in db/db mice. We focused on regulatory pathways governed by ChREBP (Carbohydrate Responsive Element Binding Protein) and FoxO1 (Forkhead box protein O1), transcription factors that play central roles in mediating the effects of glucose and fasting on gene expression, respectively. Studies using genetically modified mice reveal that hepatic TxNIP is up-regulated by both ChREBP and FoxO1 in liver cells and that its expression strongly correlates with fasting, suggesting a major role for this protein in the physiological adaptation to nutrient restriction. TxNIP is considered as a potential candidate drug target for type 2 diabetes We provide better understanding of Txnip regulation and function in liver Hepatic Txnip is up-regulated by both ChREBP and FoxO1 transcription factors We suggest a role for TxNIP in the physiological adaptation to nutrient restriction
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Affiliation(s)
- Benedicte Noblet
- Université de Paris, Institut Cochin, CNRS, INSERM, 75014 Paris, France
| | - Fadila Benhamed
- Université de Paris, Institut Cochin, CNRS, INSERM, 75014 Paris, France
| | - InSug O-Sullivan
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612.,Medical Research Service, Jesse Brown VA Medical Center, Chicago, IL 60612, USA
| | - Wenwei Zhang
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612.,Medical Research Service, Jesse Brown VA Medical Center, Chicago, IL 60612, USA
| | - Gaëlle Filhoulaud
- Université de Paris, Institut Cochin, CNRS, INSERM, 75014 Paris, France
| | - Alexandra Montagner
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France
| | - Arnaud Polizzi
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France
| | - Solenne Marmier
- Université de Paris, Institut Cochin, CNRS, INSERM, 75014 Paris, France
| | | | - Sandra Guilmeau
- Université de Paris, Institut Cochin, CNRS, INSERM, 75014 Paris, France
| | - Tarik Issad
- Université de Paris, Institut Cochin, CNRS, INSERM, 75014 Paris, France
| | - Hervé Guillou
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France
| | | | - Terry Unterman
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612.,Medical Research Service, Jesse Brown VA Medical Center, Chicago, IL 60612, USA
| | - Catherine Postic
- Université de Paris, Institut Cochin, CNRS, INSERM, 75014 Paris, France
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TXNIP/TBP-2: A Master Regulator for Glucose Homeostasis. Antioxidants (Basel) 2020; 9:antiox9080765. [PMID: 32824669 PMCID: PMC7464905 DOI: 10.3390/antiox9080765] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/09/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Identification of thioredoxin binding protein-2 (TBP-2), which is currently known as thioredoxin interacting protein (TXNIP), as an important binding partner for thioredoxin (TRX) revealed that an evolutionarily conserved reduction-oxidation (redox) signal complex plays an important role for pathophysiology. Due to the reducing activity of TRX, the TRX/TXNIP signal complex has been shown to be an important regulator for redox-related signal transduction in many types of cells in various species. In addition to its role in redox-dependent regulation, TXNIP has cellular functions that are performed in a redox-independent manner, which largely rely on their scaffolding function as an ancestral α-Arrestin family. Both the redox-dependent and -independent TXNIP functions serve as regulatory pathways in glucose metabolism. This review highlights the key advances in understanding TXNIP function as a master regulator for whole-body glucose homeostasis. The potential for therapeutic advantages of targeting TXNIP in diabetes and the future direction of the study are also discussed.
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17
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Li H, Tian S, Qin G. NADPH Oxidase Is Crucial for the Cellular Redox Homeostasis in Fungal Pathogen Botrytis cinerea. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1508-1516. [PMID: 31230563 DOI: 10.1094/mpmi-05-19-0124-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
During interactions, both plants and pathogens produce reactive oxygen species (ROS). Plants generate ROS for defense induction, while pathogens synthesize ROS for growth, sporulation, and virulence. NADPH oxidase (NOX) complex in the plasma membrane represents a main protein complex for ROS production in pathogens. Although NOX plays a crucial role in pathogenicity of pathogens, the underlying molecular mechanisms of NOX, especially the proteins regulated by NOX, remain largely unknown. Here, we applied an iodoacetyl tandem mass tag-based redox proteomic assay to investigate the protein redox dynamics in deletion mutant of bcnoxR, which encodes a regulatory subunit of NOX in the fungal pathogen Botrytis cinerea. In total, 214 unique peptidyl cysteine (Cys) thiols from 168 proteins were identified and quantified in both the wild type and ∆bcnoxR mutant. The Cys thiols in the ∆bcnoxR mutant were generally more oxidized than those in the wild type, suggesting that BcNoxR is essential for maintaining the equilibrium of the redox state in B. cinerea. Site-specific thiol oxidation analysis indicated that 142 peptides containing the oxidized thiols changed abundance significantly in the ∆bcnoxR mutant. Proteins containing these differential peptides are classified into various functional categories. Functional analysis revealed that one of these proteins, 6-phosphate dehydrogenase, played roles in oxidative stress response and pathogenesis of B. cinerea. These results provide insight into the potential target proteins and the ROS signal transduction pathway regulated by NOX.
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Affiliation(s)
- Hua Li
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shiping Tian
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Key Laboratory of Post-Harvest Handing of Fruits, Ministry of Agriculture of China, Hangzhou 310021, China
| | - Guozheng Qin
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Key Laboratory of Post-Harvest Handing of Fruits, Ministry of Agriculture of China, Hangzhou 310021, China
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18
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Deoxynivalenol Affects Cell Metabolism and Increases Protein Biosynthesis in Intestinal Porcine Epithelial Cells (IPEC-J2): DON Increases Protein Biosynthesis. Toxins (Basel) 2018; 10:toxins10110464. [PMID: 30423940 PMCID: PMC6266275 DOI: 10.3390/toxins10110464] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/22/2018] [Accepted: 11/06/2018] [Indexed: 12/16/2022] Open
Abstract
Deoxynivalenol (DON) is a toxin found in cereals as well as in processed products such as pasta, and causes substantial economic losses for stock breeding as it induces vomiting, reduced feeding, and reduced growth rates in piglets. Oxidative phosphorylation, TCA-cycle, transcription, and translation have been hypothesized to be leading pathways that are affected by DON. We used an application of high and low glucose to examine oxidative phosphorylation and anaerobic glycolysis. A change in the metabolic status of IPEC-J2 was observed and confirmed by microarray data. Measurements of oxygen consumption resulted in a significant reduction, if DON attacks from the basolateral. Furthermore, we found a dose-dependent effect with a significant reduction at 2000 ng/mL. In addition, SLC7A11 and PHB, the genes with the highest regulation in our microarray analyses under low glucose supply, were investigated and showed a variable regulation on protein level. Lactate production and glucose consumption was investigated to examine the impact of DON on anaerobic glycolysis and we observed a significant increase in 2000 blhigh and a decrease in 2000 aphigh. Interestingly, both groups as well as 200 blhigh showed a significant higher de novo protein synthesis when compared to the control. These results indicate the direct or indirect impact of DON on metabolic pathways in IPEC-J2.
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19
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Zhong L, Liu Q, Ting YS, Thien VY, Binti Kalong NS, Yang D, Wang MW. Adenine derivatives invert high glucose-induced thioredoxin-interacting protein overexpression. Chem Biol Drug Des 2018; 92:1998-2008. [PMID: 30043441 DOI: 10.1111/cbdd.13371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 07/02/2018] [Accepted: 07/07/2018] [Indexed: 12/21/2022]
Abstract
Overexpression of thioredoxin-interacting protein (TXNIP) is associated with reduced insulin sensitivity and β-cell apoptosis. We have previously shown that W2476 inhibited high glucose-induced TXNIP expression at both mRNA and protein levels in INS-1E cells. In this study, we describe structural modification and optimization of W2476 leading to three more active derivatives, 8d, 8g, and 9h, capable of suppressing TXNIP expression in BG73 and INS-1E cells, increasing insulin production, and reducing high glucose-induced apoptosis in INS-1E cells.
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Affiliation(s)
- Li Zhong
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,The National Center for Drug Screening, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qing Liu
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,The National Center for Drug Screening, Shanghai, China
| | - Yan Sie Ting
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Vun Yien Thien
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | | | - Dehua Yang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,The National Center for Drug Screening, Shanghai, China
| | - Ming-Wei Wang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,The National Center for Drug Screening, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China.,School of Pharmacy, Fudan University, Shanghai, China
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20
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Investigation of the influence of high glucose on molecular and genetic responses: an in vitro study using a human intestine model. GENES AND NUTRITION 2018; 13:11. [PMID: 29736189 PMCID: PMC5928582 DOI: 10.1186/s12263-018-0602-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/06/2018] [Indexed: 01/09/2023]
Abstract
Background Dietary glucose consumption has increased worldwide. Long-term high glucose intake contributes to the development of obesity and type 2 diabetes mellitus (T2DM). Obese people tend to eat glucose-containing foods, which can lead to an addiction to glucose, increased glucose levels in the blood and intestine lumen, and exposure of intestinal enterocytes to high dietary glucose. Recent studies have documented a role for enterocytes in glucose sensing. However, the molecular and genetic relationship between high glucose levels and intestinal enterocytes has not been determined. We aimed to identify relevant target genes and molecular pathways regulated by high glucose in a well-established in vitro epithelial cell culture model of the human intestinal system (Caco-2 cells). Methods Cells were grown in a medium containing 5.5 and 25 mM glucose in a bicameral culture system for 21 days to mimic the human intestine. Transepithelial electrical resistance was used to control monolayer formation and polarization of the cells. Total RNA was isolated, and genome-wide mRNA expression profiles were determined. Molecular pathways were analyzed using the DAVID bioinformatics program. Gene expression levels were confirmed by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Results Microarray gene expression data demonstrated that 679 genes (297 upregulated, 382 downregulated) were affected by high glucose treatment. Bioinformatics analysis indicated that intracellular protein export (p = 0.0069) and ubiquitin-mediated proteolysis (p = 0.024) pathways were induced, whereas glycolysis/gluconeogenesis (p < 0.0001), pentose phosphate (p = 0.0043), and fructose-mannose metabolism (p = 0.013) pathways were downregulated, in response to high glucose. Microarray analysis of gene expression showed that high glucose significantly induced mRNA expression levels of thioredoxin-interacting protein (TXNIP, p = 0.0001) and lipocalin 15 (LCN15, p = 0.0016) and reduced those of ATP-binding cassette, sub-family A member 1 (ABCA1, p = 0.0004), and iroquois homeobox 3 (IRX3, p = 0.0001). Conclusions To our knowledge, this is the first investigation of high glucose-regulated molecular responses in an intestinal enterocyte model. Our findings identify new target genes that may be important in the intestinal glucose absorption and metabolism during high glucose consumption.
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Alhawiti NM, Al Mahri S, Aziz MA, Malik SS, Mohammad S. TXNIP in Metabolic Regulation: Physiological Role and Therapeutic Outlook. Curr Drug Targets 2018; 18:1095-1103. [PMID: 28137209 PMCID: PMC5543564 DOI: 10.2174/1389450118666170130145514] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 01/04/2017] [Accepted: 01/25/2017] [Indexed: 12/20/2022]
Abstract
Background & Objective: Thioredoxin-interacting protein (TXNIP) also known as thioredoxin binding protein-2 is a ubiquitously expressed protein that interacts and negatively regulates expression and function of Thioredoxin (TXN). Over the last few years, TXNIP has attracted considerable attention due to its wide-ranging functions impacting several aspects of energy metabolism. TXNIP acts as an important regulator of glucose and lipid metabolism through pleiotropic actions including regulation of β-cell function, hepatic glucose production, peripheral glucose uptake, adipogenesis, and substrate utilization. Overexpression of TXNIP in animal models has been shown to induce apoptosis of pancreatic β-cells, reduce insulin sensitivity in peripheral tissues like skeletal muscle and adipose, and decrease energy expenditure. On the contrary, TXNIP deficient animals are protected from diet induced insulin resistance and type 2 diabetes. Summary: Consequently, targeting TXNIP is thought to offer novel therapeutic opportunity and TXNIP inhibitors have the potential to become a powerful therapeutic tool for the treatment of diabetes mellitus. Here we summarize the current state of our understanding of TXNIP biology, highlight its role in metabolic regulation and raise critical questions that could help future research to exploit TXNIP as a therapeutic target.
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Affiliation(s)
- Naif Mohammad Alhawiti
- Experimental Medicine, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Saeed Al Mahri
- Experimental Medicine, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Mohammad Azhar Aziz
- Colorectal Cancer Research Program, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Shuja Shafi Malik
- Experimental Medicine, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Sameer Mohammad
- Experimental Medicine, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
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22
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W2476 ameliorates β-cell dysfunction and exerts therapeutic effects in mouse models of diabetes via modulation of the thioredoxin-interacting protein signaling pathway. Acta Pharmacol Sin 2017; 38:1024-1037. [PMID: 28502980 DOI: 10.1038/aps.2017.15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 02/09/2017] [Indexed: 12/18/2022] Open
Abstract
Recent evidence shows that high glucose levels recruit carbohydrate response element-binding protein, which binds the promoter of thioredoxin-interacting protein (txnip), thereby regulating its expression in β-cells. Overexpression of txnip not only induces β-cell apoptosis but also reduces insulin production. Thus, the discovery of compounds that either inhibit TXNIP activity or suppress its expression was the focus of the present study. INS-1E cells stably transfected with either a txnip proximal glucose response element connected to a luciferase reporter plasmid (BG73) or full-length txnip promoter connected to a luciferase reporter plasmid (CL108) were used in primary and secondary high-throughput screening campaigns, respectively. From 256 000 synthetic compounds, a small molecule compound, W2476 [9-((1-(4-acetyl-phenyloxy)-ethyl)-2-)adenine], was identified as a modulator of the TXNIP-regulated signaling pathway following the screening and characterized using a battery of bioassays. The preventive and therapeutic properties of W2476 were further examined in streptozotocin-induced diabetic and diet-induced obese mice. Treatment with W2476 (1, 5, and 15 μmol/L) dose-dependently inhibited high glucose-induced TXNIP expression at the mRNA and protein levels in INS-1E cells and rat pancreatic islets. Furthermore, W2476 treatment prevented INS-1E cells from apoptosis induced by chronic exposure of high glucose and enhanced insulin production in vitro. Oral administration of W2476 (200 mg·kg-1·d-1) rescued streptozotocin-induced diabetic mice by promoting β-cell survival and enhancing insulin secretion. This therapeutic property of W2476 was further demonstrated by its ability to improve glucose homeostasis and insulin sensitivity in diet-induced obese mice. Thus, chemical intervention of the TXNIP-regulated signaling pathway might present a viable approach to manage diabetes.
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23
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Tyagi SC, Rodriguez W, Patel AM, Roberts AM, Falcone JC, Passmore JC, Fleming JT, Joshua IG. Hyperhomocysteinemic Diabetic Cardiomyopathy: Oxidative Stress, Remodeling, and Endothelial-Myocyte Uncoupling. J Cardiovasc Pharmacol Ther 2016; 10:1-10. [PMID: 15821833 DOI: 10.1177/107424840501000101] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Accumulation of oxidized-matrix (fibrosis) between the endothelium (the endothelial cells embedded among the myocytes) and cardiomyocytes is a hallmark of diabetes mellitus and causes diastolic impairment. In diabetes mellitus, elevated levels of homocysteine activate matrix metalloproteinase and disconnect the endothelium from myocytes. Extracellular matrix functionally links the endothelium to the cardiomyocyte and is important for their synchronization. However, in diabetes mellitus, a disconnection is caused by activated metalloproteinase, with subsequent accumulation of oxidized matrix between the endothelium and myocyte. This contributes to endothelial-myocyte uncoupling and leads to impaired diastolic relaxation of the heart in diabetes mellitus. Elevated levels of homocysteine in diabetes are attributed to impaired homocysteine metabolism by glucose and insulin and decreased renal clearance. Homocysteine induces oxidative stress and is inversely related to the expression of peroxisome proliferators activated receptor (PPAR). Several lines of evidence suggest that ablation of the matrix metalloproteinase (MMP-9) gene ameliorates the endothelial-myocyte uncoupling in diabetes mellitus. Homocysteine competes for, and decreases the PPARγ activity. In diabetes mellitus, endothelial-myocyte uncoupling is associated with matrix metalloproteinase activation and decreased PPARγ activity. The purpose of this review is to discuss the role of endothelial-myocyte uncoupling in diabetes mellitus and increased levels of homocysteine, causing activation of latent metalloproteinases, decreased levels of thioredoxin and peroxiredoxin, and cardiac tissue inhibitor of metalloproteinase (CIMP) in response to antagonizing PPARγ.
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Affiliation(s)
- Suresh C Tyagi
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA.
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Eren E, Aykal G, Sayrac S, Erol O, Ellidag HY, Yilmaz N. Relationship between thioredoxin and thioredoxin-binding protein in patients with gestational diabetes mellitus. J Matern Fetal Neonatal Med 2016; 30:164-168. [PMID: 26955974 DOI: 10.3109/14767058.2016.1163685] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE This study examined the clinical and biological significance of thioredoxin (Trx) and thioredoxin-binding protein (TrxBP), which are redox-active proteins that control multiple biological functions, in gestational diabetes. METHODS We measured serum concentrations of Trx, TrxBP, insulin and other blood parameters, as well as insulin resistance and glucose tolerance in pregnant women with or without gestational dieabetes mellitus (GDM) (34/34) at the early second trimester. RESULTS Contrary to diabetes patients, serum TrxBP levels were lower in women with GDM than healthy pregnant controls. The serum insulin concentrations were higher in GDM, but the difference was not statistically significant. Furthermore, the intracellular redox potential ratio (Trx/TrxBP) of GDM patients was higher than that of the control group. CONCLUSION During pregnancy, the mother is potentially subjected to glucotoxicity as well as oxidative stress (OS) to help the foetus absorb more nutrients. Our results suggest that the Trx/TrxBP system may mediate a compensating mechanism. Reduced TrxBP levels and consequent enhanced Trx activity may alleviate OS and protect the foetus from hypoglycaemia. We hypothesise that the decrease in TrxBP levels is not a consequence of GDM, but rather is an instance of the active functional role of TrxBP in maternal development, unifying redox regulation and glucose metabolism.
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Affiliation(s)
- Esin Eren
- a Department of Clinical Biochemistry , Central Laboratories of Antalya Training and Research Hospital , Antalya , Turkey
| | - Guzin Aykal
- a Department of Clinical Biochemistry , Central Laboratories of Antalya Training and Research Hospital , Antalya , Turkey
| | - Suha Sayrac
- b Research and Development Unit, Antalya Association of Public Hospitals , Antalya , Turkey , and
| | - Onur Erol
- c Department of Gynecology and Obstetrics , Antalya Training and Research Hospital , Antalya , Turkey
| | - Hamit Yasar Ellidag
- a Department of Clinical Biochemistry , Central Laboratories of Antalya Training and Research Hospital , Antalya , Turkey
| | - Necat Yilmaz
- a Department of Clinical Biochemistry , Central Laboratories of Antalya Training and Research Hospital , Antalya , Turkey
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Liu S, Wu X, Zong M, Tempel W, Loppnau P, Liu Y. Structural basis for a novel interaction between TXNIP and Vav2. FEBS Lett 2016; 590:857-65. [DOI: 10.1002/1873-3468.12110] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/08/2016] [Accepted: 02/17/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Shasha Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology; College of Life Science; Central China Normal University; Wuhan China
| | - Xue Wu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology; College of Life Science; Central China Normal University; Wuhan China
| | - Minru Zong
- China-Japan Union Hospital of Jilin University; Changchun China
| | - Wolfram Tempel
- Structural Genomics Consortium; University of Toronto; Ontario Canada
| | - Peter Loppnau
- Structural Genomics Consortium; University of Toronto; Ontario Canada
| | - Yanli Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology; College of Life Science; Central China Normal University; Wuhan China
- Structural Genomics Consortium; University of Toronto; Ontario Canada
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Affiliation(s)
- Ethan J Anderson
- Department of Pharmacology & Toxicology, Center for Health Disparities, East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC
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Byon CH, Han T, Wu J, Hui ST. Txnip ablation reduces vascular smooth muscle cell inflammation and ameliorates atherosclerosis in apolipoprotein E knockout mice. Atherosclerosis 2015; 241:313-21. [PMID: 26062991 DOI: 10.1016/j.atherosclerosis.2015.05.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 05/09/2015] [Accepted: 05/17/2015] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Inflammation of vascular smooth muscle cells (VSMC) is intimately linked to atherosclerosis and other vascular inflammatory disease. Thioredoxin interacting protein (Txnip) is a key regulator of cellular sulfhydryl redox and a mediator of inflammasome activation. The goals of the present study were to examine the impact of Txnip ablation on inflammatory response to oxidative stress in VSMC and to determine the effect of Txnip ablation on atherosclerosis in vivo. METHODS AND RESULTS Using cultured VSMC, we showed that ablation of Txnip reduced cellular oxidative stress and increased protection from oxidative stress when challenged with oxidized phospholipids and hydrogen peroxide. Correspondingly, expression of inflammatory markers and adhesion molecules were diminished in both VSMC and macrophages from Txnip knockout mice. The blunted inflammatory response was associated with a decrease in NF-ĸB nuclear translocation. Loss of Txnip in VSMC also led to a dramatic reduction in macrophage adhesion to VSMC. In vivo data from Txnip-ApoE double knockout mice showed that Txnip ablation led to 49% reduction in atherosclerotic lesion in the aortic root and 71% reduction in the abdominal aorta, compared to control ApoE knockout mice. CONCLUSION Our data show that Txnip plays an important role in oxidative inflammatory response and atherosclerotic lesion development in mice. The atheroprotective effect of Txnip ablation implicates that modulation of Txnip expression may serve as a potential target for intervention of atherosclerosis and inflammatory vascular disease.
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Affiliation(s)
- Chang Hyun Byon
- Division of Cardiology, Department of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Tieyan Han
- Division of Cardiology, Department of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Judy Wu
- Division of Cardiology, Department of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Simon T Hui
- Division of Cardiology, Department of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA.
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Shalev A. Minireview: Thioredoxin-interacting protein: regulation and function in the pancreatic β-cell. Mol Endocrinol 2014; 28:1211-20. [PMID: 24911120 DOI: 10.1210/me.2014-1095] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Pancreatic β-cells are responsible for insulin production, and loss of functional β-cell mass is now recognized as a critical step in the pathogenesis of both type 1 and type 2 diabetes. However, the factors controlling the life and death of the pancreatic β-cell have only started to be elucidated. Discovered as the top glucose-induced gene in a human islet microarray study 12 years ago, thioredoxin-interacting protein (TXNIP) has now emerged as such a key player in pancreatic β-cell biology. Since then, β-cell expression of TXNIP has been found to be tightly regulated by multiple factors and to be dramatically increased in diabetic islets. Elevated TXNIP levels induce β-cell apoptosis, whereas TXNIP deficiency protects against type 1 and type 2 diabetes by promoting β-cell survival. TXNIP interacts with and inhibits thioredoxin and thereby controls the cellular redox state, but it also belongs to the α-arrestin family of proteins and regulates a variety of metabolic processes. Most recently, TXNIP has been discovered to control β-cell microRNA expression, β-cell function, and insulin production. In this review, the current state of knowledge regarding regulation and function of TXNIP in the pancreatic β-cell and the implications for drug development are discussed.
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Affiliation(s)
- Anath Shalev
- Comprehensive Diabetes Center and Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama 35294
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Thioredoxin system regulation in the central nervous system: experimental models and clinical evidence. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:590808. [PMID: 24723994 PMCID: PMC3958682 DOI: 10.1155/2014/590808] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 01/21/2014] [Accepted: 01/23/2014] [Indexed: 02/07/2023]
Abstract
The reactive oxygen species produced continuously during oxidative metabolism are generated at very high rates in the brain. Therefore, defending against oxidative stress is an essential task within the brain. An important cellular system against oxidative stress is the thioredoxin system (TS). TS is composed of thioredoxin, thioredoxin reductase, and NADPH. This review focuses on the evidence gathered in recent investigations into the central nervous system, specifically the different brain regions in which the TS is expressed. Furthermore, we address the conditions that modulate the thioredoxin system in both, animal models and the postmortem brains of human patients associated with the most common neurodegenerative disorders, in which the thioredoxin system could play an important part.
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DeBalsi KL, Wong KE, Koves TR, Slentz DH, Seiler SE, Wittmann AH, Ilkayeva OR, Stevens RD, Perry CGR, Lark DS, Hui ST, Szweda L, Neufer PD, Muoio DM. Targeted metabolomics connects thioredoxin-interacting protein (TXNIP) to mitochondrial fuel selection and regulation of specific oxidoreductase enzymes in skeletal muscle. J Biol Chem 2014; 289:8106-20. [PMID: 24482226 DOI: 10.1074/jbc.m113.511535] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thioredoxin-interacting protein (TXNIP) is an α-arrestin family member involved in redox sensing and metabolic control. Growing evidence links TXNIP to mitochondrial function, but the molecular nature of this relationship has remained poorly defined. Herein, we employed targeted metabolomics and comprehensive bioenergetic analyses to evaluate oxidative metabolism and respiratory kinetics in mouse models of total body (TKO) and skeletal muscle-specific (TXNIP(SKM-/-)) Txnip deficiency. Compared with littermate controls, both TKO and TXNIP(SKM-/-) mice had reduced exercise tolerance in association with muscle-specific impairments in substrate oxidation. Oxidative insufficiencies in TXNIP null muscles were not due to perturbations in mitochondrial mass, the electron transport chain, or emission of reactive oxygen species. Instead, metabolic profiling analyses led to the discovery that TXNIP deficiency causes marked deficits in enzymes required for catabolism of branched chain amino acids, ketones, and lactate, along with more modest reductions in enzymes of β-oxidation and the tricarboxylic acid cycle. The decrements in enzyme activity were accompanied by comparable deficits in protein abundance without changes in mRNA expression, implying dysregulation of protein synthesis or stability. Considering that TXNIP expression increases in response to starvation, diabetes, and exercise, these findings point to a novel role for TXNIP in coordinating mitochondrial fuel switching in response to nutrient availability.
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Abdelsaid MA, Matragoon S, El-Remessy AB. Thioredoxin-interacting protein expression is required for VEGF-mediated angiogenic signal in endothelial cells. Antioxid Redox Signal 2013; 19:2199-212. [PMID: 23718729 PMCID: PMC3869450 DOI: 10.1089/ars.2012.4761] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
AIMS Thioredoxin-interacting protein (TXNIP) contributes to cellular redox-state homeostasis via binding and inhibiting thioredoxin (TRX). Increasing evidence suggests that cellular redox homeostasis regulates vascular endothelial growth factor (VEGF)-mediated signaling. This study aims to examine the redox-dependant role of TXNIP in regulating VEGF-mediated S-glutathionylation and angiogenic signaling. TXNIP-knockout mice (TKO) or wild-type (WT) treated with the reduced glutathione (GSH)-precursor, N-acetyl cysteine (WT-NAC, 500 mg/kg) were compared to WT using hypoxia-induced neovascularization model. RESULTS In response to hypoxia, retinas from TKO and WT-NAC mice showed significant decreases in reparative revascularization and pathological neovascularization with similar VEGF expression compared with WT. VEGF failed to stimulate vascular sprouting from aortic rings of TKO compared to WT mice. TKO mice or WT+NAC experienced reductive stress as indicated by twofold increase in TRX reductase activity and fourfold increase in reduced-GSH levels compared with WT. In human microvascular endothelial (HME) cells, VEGF stimulated co-precipitation between vascular endothelial growth factor receptor 2 (VEGFR2) with low molecular weight protein tyrosine phosphatase (LMW-PTP). Silencing TXNIP expression blunted VEGF-induced oxidation of GSH and S-glutathionylation of the LMW-PTP in HME cells. These effects were associated with impaired VEGFR2 phosphorylation that culminated in inhibiting cell migration and tube formation. Overexpression of TXNIP restored VEGFR2 phosphorylation and cell migration in TKO-endothelial cells. INNOVATION TXNIP expression is required for VEGF-mediated VEGFR2 activation and angiogenic response in vivo and in vitro. TXNIP expression regulates VEGFR-2 phosphorylation via S-glutathionylation of LMW-PTP in endothelial cells. CONCLUSION Our results provide novel mechanistic insight into modulating TXNIP expression as a potential therapeutic target in diseases characterized by aberrant angiogenesis.
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Affiliation(s)
- Mohammed A Abdelsaid
- 1 Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia , Augusta, Georgia
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Mahmood DFD, Abderrazak A, El Hadri K, Simmet T, Rouis M. The thioredoxin system as a therapeutic target in human health and disease. Antioxid Redox Signal 2013; 19:1266-303. [PMID: 23244617 DOI: 10.1089/ars.2012.4757] [Citation(s) in RCA: 225] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The thioredoxin (Trx) system comprises Trx, truncated Trx (Trx-80), Trx reductase, and NADPH, besides a natural Trx inhibitor, the thioredoxin-interacting protein (TXNIP). This system is essential for maintaining the balance of the cellular redox status, and it is involved in the regulation of redox signaling. It is also pivotal for growth promotion, neuroprotection, inflammatory modulation, antiapoptosis, immune function, and atherosclerosis. As an ubiquitous and multifunctional protein, Trx is expressed in all forms of life, executing its function through its antioxidative, protein-reducing, and signal-transducing activities. In this review, the biological properties of the Trx system are highlighted, and its implications in several human diseases are discussed, including cardiovascular diseases, heart failure, stroke, inflammation, metabolic syndrome, neurodegenerative diseases, arthritis, and cancer. The last chapter addresses the emerging therapeutic approaches targeting the Trx system in human diseases.
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Lekva T, Bollerslev J, Sahraoui A, Scholz H, Bøyum H, Evang JA, Godang K, Aukrust P, Ueland T. Thioredoxin interacting protein is a potential regulator of glucose and energy homeostasis in endogenous Cushing's syndrome. PLoS One 2013; 8:e64247. [PMID: 23691179 PMCID: PMC3656831 DOI: 10.1371/journal.pone.0064247] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 04/10/2013] [Indexed: 12/13/2022] Open
Abstract
Recent studies have described bone as an endocrine organ regulating glucose metabolism, with insulin signaling regulating osteocalcin secretion and osteocalcin regulating β cell function. We have previously demonstrated increased bone expression of TXNIP in patients with endogenous Cushing's syndrome (CS), and we hypothesized that TXNIP could contribute to the dysregulated glucose metabolism in CS. We studied 33 CS patients and 29 matched controls, with bone biopsies from nine patients, before and after surgical treatment. In vitro, the effect of silencing TXNIP (siTXNIP) in osteoblasts, including its effect on human islet cells, was examined. Our major findings were: (i) The high mRNA levels of TXNIP in bone from CS patients were significantly associated with high levels of glucose and insulin, increased insulin resistance, and decreased insulin sensitivity in these patients. (ii) Silencing TXNIP in osteoblasts enhanced their OC response to insulin and glucose and down-regulated interleukin (IL)-8 levels in these cells. (iii) Conditional media from siTXNIP-treated osteoblasts promoted insulin content and anti-inflammatory responses in human islet cells. We recently demonstrated that the thioredoxin/TXNIP axis may mediate some detrimental effects of glucocorticoid excess on bone tissue in CS. Here we show that alterations in this axis also may affect glucose metabolism in these patients.
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Affiliation(s)
- Tove Lekva
- Section of Specialized Endocrinology, Department of Endocrinology, Oslo University Hospital, Oslo, Norway.
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Lee S, Kim SM, Lee RT. Thioredoxin and thioredoxin target proteins: from molecular mechanisms to functional significance. Antioxid Redox Signal 2013; 18:1165-207. [PMID: 22607099 PMCID: PMC3579385 DOI: 10.1089/ars.2011.4322] [Citation(s) in RCA: 268] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The thioredoxin (Trx) system is one of the central antioxidant systems in mammalian cells, maintaining a reducing environment by catalyzing electron flux from nicotinamide adenine dinucleotide phosphate through Trx reductase to Trx, which reduces its target proteins using highly conserved thiol groups. While the importance of protecting cells from the detrimental effects of reactive oxygen species is clear, decades of research in this field revealed that there is a network of redox-sensitive proteins forming redox-dependent signaling pathways that are crucial for fundamental cellular processes, including metabolism, proliferation, differentiation, migration, and apoptosis. Trx participates in signaling pathways interacting with different proteins to control their dynamic regulation of structure and function. In this review, we focus on Trx target proteins that are involved in redox-dependent signaling pathways. Specifically, Trx-dependent reductive enzymes that participate in classical redox reactions and redox-sensitive signaling molecules are discussed in greater detail. The latter are extensively discussed, as ongoing research unveils more and more details about the complex signaling networks of Trx-sensitive signaling molecules such as apoptosis signal-regulating kinase 1, Trx interacting protein, and phosphatase and tensin homolog, thus highlighting the potential direct and indirect impact of their redox-dependent interaction with Trx. Overall, the findings that are described here illustrate the importance and complexity of Trx-dependent, redox-sensitive signaling in the cell. Our increasing understanding of the components and mechanisms of these signaling pathways could lead to the identification of new potential targets for the treatment of diseases, including cancer and diabetes.
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Affiliation(s)
- Samuel Lee
- The Harvard Stem Cell Institute, Cambridge, MA, USA
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Wu N, Zheng B, Shaywitz A, Dagon Y, Tower C, Bellinger G, Shen CH, Wen J, Asara J, McGraw TE, Kahn BB, Cantley LC. AMPK-dependent degradation of TXNIP upon energy stress leads to enhanced glucose uptake via GLUT1. Mol Cell 2013; 49:1167-75. [PMID: 23453806 PMCID: PMC3615143 DOI: 10.1016/j.molcel.2013.01.035] [Citation(s) in RCA: 457] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 12/06/2012] [Accepted: 01/25/2013] [Indexed: 12/25/2022]
Abstract
Thioredoxin-interacting protein (TXNIP) is an α-arrestin family protein that is induced in response to glucose elevation. It has been shown to provide a negative feedback loop to regulate glucose uptake into cells, though the biochemical mechanism of action has been obscure. Here, we report that TXNIP suppresses glucose uptake directly, by binding to the glucose transporter GLUT1 and inducing GLUT1 internalization through clathrin-coated pits, as well as indirectly, by reducing the level of GLUT1 messenger RNA (mRNA). In addition, we show that energy stress results in the phosphorylation of TXNIP by AMP-dependent protein kinase (AMPK), leading to its rapid degradation. This suppression of TXNIP results in an acute increase in GLUT1 function and an increase in GLUT1 mRNA (hence the total protein levels) for long-term adaptation. The glucose influx through GLUT1 restores ATP-to-ADP ratios in the short run and ultimately induces TXNIP protein production to suppress glucose uptake once energy homeostasis is reestablished.
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Affiliation(s)
- Ning Wu
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, MA 02115
| | - Bin Zheng
- Institute for Cancer Genetics, Columbia University Medical Center, New York, NY 10032
| | - Adam Shaywitz
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, MA 02115
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02115
| | - Yossi Dagon
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02115
| | - Christine Tower
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, MA 02115
| | - Gary Bellinger
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, MA 02115
| | - Che-Hung Shen
- Institute for Cancer Genetics, Columbia University Medical Center, New York, NY 10032
| | - Jennifer Wen
- Department of Biochemistry, Weill Medical College of Cornell University, New York, NY 10065
| | - John Asara
- Mass Spectrometry Core, Beth Israel Deaconess Medical Center, Boston, MA 02115
| | - Timothy E. McGraw
- Department of Biochemistry, Weill Medical College of Cornell University, New York, NY 10065
| | - Barbara B. Kahn
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02115
| | - Lewis C. Cantley
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, MA 02115
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Polekhina G, Ascher DB, Kok SF, Beckham S, Wilce M, Waltham M. Structure of the N-terminal domain of human thioredoxin-interacting protein. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:333-44. [PMID: 23519408 DOI: 10.1107/s0907444912047099] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 11/15/2012] [Indexed: 11/10/2022]
Abstract
Thioredoxin-interacting protein (TXNIP) is one of the six known α-arrestins and has recently received considerable attention owing to its involvement in redox signalling and metabolism. Various stress stimuli such as high glucose, heat shock, UV, H2O2 and mechanical stress among others robustly induce the expression of TXNIP, resulting in the sequestration and inactivation of thioredoxin, which in turn leads to cellular oxidative stress. While TXNIP is the only α-arrestin known to bind thioredoxin, TXNIP and two other α-arrestins, Arrdc4 and Arrdc3, have been implicated in metabolism. Furthermore, owing to its roles in the pathologies of diabetes and cardiovascular disease, TXNIP is considered to be a promising drug target. Based on their amino-acid sequences, TXNIP and the other α-arrestins are remotely related to β-arrestins. Here, the crystal structure of the N-terminal domain of TXNIP is reported. It provides the first structural information on any of the α-arrestins and reveals that although TXNIP adopts a β-arrestin fold as predicted, it is structurally more similar to Vps26 proteins than to β-arrestins, while sharing below 15% pairwise sequence identity with either.
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Affiliation(s)
- Galina Polekhina
- Centre for Cancer Research, Monash Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton, VIC 3168, Australia.
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TXNIP in Agrp neurons regulates adiposity, energy expenditure, and central leptin sensitivity. J Neurosci 2012; 32:9870-7. [PMID: 22815502 DOI: 10.1523/jneurosci.0353-12.2012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Thioredoxin interacting protein (TXNIP) has recently been described as a key regulator of energy metabolism through pleiotropic actions that include nutrient sensing in the mediobasal hypothalamus (MBH). However, the role of TXNIP in neurochemically specific hypothalamic subpopulations and the circuits downstream from MBH TXNIP engaged to regulate energy homeostasis remain unexplored. To evaluate the metabolic role of TXNIP activity specifically within arcuate Agrp neurons, we generated Agrp-specific TXNIP gain-of-function and loss-of-function mouse models using Agrp-Ires-cre mice, TXNIP (flox/flox) mice, and a lentivector expressing the human TXNIP isoform conditionally in the presence of Cre recombinase. Overexpression of TXNIP in Agrp neurons predisposed to diet-induced obesity and adipose tissue storage by decreasing energy expenditure and spontaneous locomotion, without affecting food intake. Conversely, Agrp neuronal TXNIP deletion protected against diet-induced obesity and adipose tissue storage by increasing energy expenditure and spontaneous locomotion, also without affecting food intake. TXNIP overexpression in Agrp neurons did not primarily affect glycemic control, whereas deletion of TXNIP in Agrp neurons improved fasting glucose levels and glucose tolerance independently of its effects on body weight and adiposity. Bidirectional manipulation of TXNIP expression induced reciprocal changes in central leptin sensitivity and the neural regulation of lipolysis. Together, these results identify a critical role for TXNIP in Agrp neurons in mediating diet-induced obesity through the regulation of energy expenditure and adipose tissue metabolism, independently of food intake. They also reveal a previously unidentified role for Agrp neurons in the brain-adipose axis.
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Lerner AG, Upton JP, Praveen PVK, Ghosh R, Nakagawa Y, Igbaria A, Shen S, Nguyen V, Backes BJ, Heiman M, Heintz N, Greengard P, Hui S, Tang Q, Trusina A, Oakes SA, Papa FR. IRE1α induces thioredoxin-interacting protein to activate the NLRP3 inflammasome and promote programmed cell death under irremediable ER stress. Cell Metab 2012; 16:250-64. [PMID: 22883233 PMCID: PMC4014071 DOI: 10.1016/j.cmet.2012.07.007] [Citation(s) in RCA: 647] [Impact Index Per Article: 53.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 06/05/2012] [Accepted: 07/17/2012] [Indexed: 12/12/2022]
Abstract
When unfolded proteins accumulate to irremediably high levels within the endoplasmic reticulum (ER), intracellular signaling pathways called the unfolded protein response (UPR) become hyperactivated to cause programmed cell death. We discovered that thioredoxin-interacting protein (TXNIP) is a critical node in this "terminal UPR." TXNIP becomes rapidly induced by IRE1α, an ER bifunctional kinase/endoribonuclease (RNase). Hyperactivated IRE1α increases TXNIP mRNA stability by reducing levels of a TXNIP destabilizing microRNA, miR-17. In turn, elevated TXNIP protein activates the NLRP3 inflammasome, causing procaspase-1 cleavage and interleukin 1β (IL-1β) secretion. Txnip gene deletion reduces pancreatic β cell death during ER stress and suppresses diabetes caused by proinsulin misfolding in the Akita mouse. Finally, small molecule IRE1α RNase inhibitors suppress TXNIP production to block IL-1β secretion. In summary, the IRE1α-TXNIP pathway is used in the terminal UPR to promote sterile inflammation and programmed cell death and may be targeted to develop effective treatments for cell degenerative diseases.
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Affiliation(s)
- Alana G Lerner
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
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Masaki S, Masutani H, Yoshihara E, Yodoi J. Deficiency of thioredoxin binding protein-2 (TBP-2) enhances TGF-β signaling and promotes epithelial to mesenchymal transition. PLoS One 2012; 7:e39900. [PMID: 22768160 PMCID: PMC3387201 DOI: 10.1371/journal.pone.0039900] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 05/28/2012] [Indexed: 12/29/2022] Open
Abstract
Background Transforming growth factor beta (TGF-β) has critical roles in regulating cell growth, differentiation, apoptosis, invasion and epithelial-mesenchymal transition (EMT) of various cancer cells. TGF-β-induced EMT is an important step during carcinoma progression to invasion state. Thioredoxin binding protein-2 (TBP-2, also called Txnip or VDUP1) is downregulated in various types of human cancer, and its deficiency results in the earlier onset of cancer. However, it remains unclear how TBP-2 suppresses the invasion and metastasis of cancer. Principal Findings In this study, we demonstrated that TBP-2 deficiency increases the transcriptional activity in response to TGF-β and also enhances TGF-β-induced Smad2 phosphorylation levels. Knockdown of TBP-2 augmented the TGF-β-responsive expression of Snail and Slug, transcriptional factors related to TGF-β-mediated induction of EMT, and promoted TGF-β-induced spindle-like morphology consistent with the depletion of E-Cadherin in A549 cells. Conclusions/Significance Our results indicate that TBP-2 deficiency enhances TGF-β signaling and promotes TGF-β-induced EMT. The control of TGF-β-induced EMT is critical for the inhibition of the invasion and metastasis. Thus TBP-2, as a novel regulatory molecule of TGF-β signaling, is likely to be a prognostic indicator or a potential therapeutic target for preventing tumor progression.
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Affiliation(s)
- So Masaki
- Laboratory of Infection and Prevention, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Hiroshi Masutani
- Laboratory of Infection and Prevention, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Eiji Yoshihara
- Laboratory of Infection and Prevention, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Junji Yodoi
- Laboratory of Infection and Prevention, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto, Japan
- Department of Bioinspired Sciences, Center for Cell Signaling Research, Ewha Womans University, Seoul, South Korea
- * E-mail:
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Patwari P, Lee RT. An expanded family of arrestins regulate metabolism. Trends Endocrinol Metab 2012; 23:216-22. [PMID: 22520962 PMCID: PMC3348262 DOI: 10.1016/j.tem.2012.03.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 03/13/2012] [Accepted: 03/13/2012] [Indexed: 11/24/2022]
Abstract
The classical visual and β-arrestins belong to a larger family of proteins that likely share structural similarity. Humans have an additional six related proteins sometimes termed the α-arrestins, whose functions are now emerging. Surprisingly, several α-arrestins play prominent roles in the regulation of metabolism and obesity. One α-arrestin, thioredoxin-interacting protein (Txnip), has crucial functions in regulating glucose uptake and glycolytic flux through the mitochondria. Another α-arrestin, Arrdc3, is linked to obesity in men and was recently identified in mice as a regulator of body mass, adiposity, and energy expenditure. Here we discuss recent evidence suggesting potential common themes for all arrestins, including physiological roles for classical arrestins in metabolism and the functions of α-arrestins in receptor signaling and endocytosis.
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Affiliation(s)
- Parth Patwari
- Harvard Stem Cell Institute and the Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Cambridge, MA 02139, USA
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Spindel ON, World C, Berk BC. Thioredoxin interacting protein: redox dependent and independent regulatory mechanisms. Antioxid Redox Signal 2012; 16:587-96. [PMID: 21929372 PMCID: PMC3270053 DOI: 10.1089/ars.2011.4137] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 09/19/2011] [Accepted: 09/19/2011] [Indexed: 12/18/2022]
Abstract
SIGNIFICANCE The thioredoxin-interacting protein (TXNIP, also termed VDUP1 for vitamin D upregulated protein or TBP2 for thioredoxin-binding protein) was originally discovered by virtue of its strong regulation by vitamin D. Recently, TXNIP has been found to regulate the cellular reduction-oxidation (redox) state by binding to and inhibiting thioredoxin (TRX) in a redox-dependent fashion. RECENT ADVANCES Studies of the Hcb-19 mouse, TXNIP nonsense mutated mouse, demonstrate redox-mediated roles in lipid and glucose metabolism, cardiac function, inflammation, and carcinogenesis. Exciting recent data indicate important roles for TXNIP in redox independent signaling. Specifically, sequence analysis revealed that TXNIP is a member of the classical visual/β-arrestin superfamily, and is one of the six members of the arrestin domain-containing (ARRDC, or α-arrestin) family. CRITICAL ISSUES Although the function of α-arrestins is not well known, recent studies suggest roles in endocytosis and protein ubiquitination through PPxY motifs in their C-terminal tails. Importantly, the ability of TXNIP to inhibit glucose uptake was found to be independent of TRX binding. Further investigation showed that several metabolic functions of TXNIP were due to the arrestin domains, thus further supporting the importance of redox independent functions of TXNIP. FUTURE DIRECTIONS Since TXNIP transcription and protein stability are highly regulated by multiple tissue-specific stimuli, it appears that TXNIP should be a good therapeutic target for metabolic diseases.
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Affiliation(s)
- Oded N. Spindel
- Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York
- Department of Pharmacology and Physiology, Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Cameron World
- Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Bradford C. Berk
- Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York
- Department of Pharmacology and Physiology, Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, New York
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Spindel ON, Yan C, Berk BC. Thioredoxin-interacting protein mediates nuclear-to-plasma membrane communication: role in vascular endothelial growth factor 2 signaling. Arterioscler Thromb Vasc Biol 2012; 32:1264-70. [PMID: 22345166 DOI: 10.1161/atvbaha.111.244681] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Thioredoxin-interacting protein (TXNIP) and poly-ADP-ribose polymerase 1 (PARP1) are both regulated by changes in cellular reduction-oxidation (redox) state and localize to the nucleus basally in human umbilical vein endothelial cells (HUVEC). Previously we showed a novel mechanism for PARP1 inhibition-mediated HUVEC survival through activation of vascular endothelial growth factor receptor 2 (VEGFR2) signaling in response to stress-induced apoptosis. In addition, we showed TXNIP translocation to the plasma membrane (PM) and activation of VEGFR2 in response to physiological stimuli. Because TXNIP is an α-arrestin that regulates VEGFR2 signaling, we hypothesized that PARP1 regulates TXNIP localization and function that might affect HUVEC stress-induced apoptosis. METHODS AND RESULTS HUVEC treated with 10 μmol/L PARP1 inhibitor (PJ34) were protected from TNF (10 ng/mL) or H(2)O(2) (300 μmol/L) mediated cell death. HUVEC transfected with TXNIP siRNA lost the protective effect of PARP1 inhibition, suggesting a protective role for TXNIP. Using immunofluorescence, cell fractionation analysis, and plasma membrane sheet assay, TXNIP was shown to translocate to the plasma membrane after PARP1 inhibition. TXNIP translocation was associated with activation of VEGFR2 signaling. Functionally, TXNIP-PARP1 interaction was decreased on PJ34 treatment, suggesting PARP1 as a novel regulator of TXNIP localization and function. CONCLUSIONS These findings demonstrate a novel regulatory mechanism of TXNIP by PARP1 to mediate activation of plasma membrane signaling and cell survival.
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Affiliation(s)
- Oded N Spindel
- Department of Medicine, University of Rochester School of Medicine and Dentistry, Aab Cardiovascular Research Institute, Rochester, NY 14642, USA
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Styskal J, Van Remmen H, Richardson A, Salmon AB. Oxidative stress and diabetes: what can we learn about insulin resistance from antioxidant mutant mouse models? Free Radic Biol Med 2012; 52:46-58. [PMID: 22056908 PMCID: PMC3249484 DOI: 10.1016/j.freeradbiomed.2011.10.441] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 10/12/2011] [Accepted: 10/13/2011] [Indexed: 01/18/2023]
Abstract
The development of metabolic dysfunctions like diabetes and insulin resistance in mammals is regulated by a myriad of factors. Oxidative stress seems to play a central role in this process as recent evidence shows a general increase in oxidative damage and a decrease in oxidative defense associated with several metabolic diseases. These changes in oxidative stress can be directly correlated with increased fat accumulation, obesity, and consumption of high-calorie/high-fat diets. Modulation of oxidant protection through either genetic mutation or treatment with antioxidants can significantly alter oxidative stress resistance and accumulation of oxidative damage in laboratory rodents. Antioxidant mutant mice have previously been utilized to examine the role of oxidative stress in other disease models, but have been relatively unexplored as models to study the regulation of glucose metabolism. In this review, we will discuss the evidence for oxidative stress as a primary mechanism linking obesity and metabolic disorders and whether alteration of antioxidant status in laboratory rodents can significantly alter the development of insulin resistance or diabetes.
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Affiliation(s)
- Jennalynn Styskal
- The Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA
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Esposito M, Pellinen J, Kapás L, Szentirmai É. Impaired wake-promoting mechanisms in ghrelin receptor-deficient mice. Eur J Neurosci 2011; 35:233-43. [PMID: 22211783 DOI: 10.1111/j.1460-9568.2011.07946.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ghrelin receptors are expressed by key components of the arousal system. Exogenous ghrelin induces behavioral activation, promotes wakefulness and stimulates eating. We hypothesized that ghrelin-sensitive mechanisms play a role in the arousal system. To test this, we investigated the responsiveness of ghrelin receptor knockout (KO) mice to two natural wake-promoting stimuli. Additionally, we assessed the integrity of their homeostatic sleep-promoting system using sleep deprivation. There was no significant difference in the spontaneous sleep-wake activity between ghrelin receptor KO and wild-type (WT) mice. WT mice mounted robust arousal responses to a novel environment and food deprivation. Wakefulness increased for 6 h after cage change accompanied by increases in body temperature and locomotor activity. Ghrelin receptor KO mice completely lacked the wake and body temperature responses to new environment. When subjected to 48 h food deprivation, WT mice showed marked increases in their waking time during the dark periods of both days. Ghrelin receptor KO mice failed to mount an arousal response on the first night and wake increases were attenuated on the second day. The responsiveness to sleep deprivation did not differ between the two genotypes. These results indicate that the ghrelin-receptive mechanisms play an essential role in the function of the arousal system but not in homeostatic sleep-promoting mechanisms.
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Affiliation(s)
- Matthew Esposito
- Washington, Wyoming, Alaska, Montana and Idaho (WWAMI) Medical Education Program, Washington State University, PO Box 1495, Spokane, WA 99210-1495, USA
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Elgort MG, O'Shea JM, Jiang Y, Ayer DE. Transcriptional and Translational Downregulation of Thioredoxin Interacting Protein Is Required for Metabolic Reprogramming during G(1). Genes Cancer 2011; 1:893-907. [PMID: 21779470 DOI: 10.1177/1947601910389604] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 10/12/2010] [Accepted: 10/16/2010] [Indexed: 12/21/2022] Open
Abstract
Growth factor signaling drives increased glucose uptake and glycolysis-the Warburg effect-that supports macromolecular synthesis necessary for cell growth and proliferation. Thioredoxin interacting protein (TXNIP), a direct and glucose-induced transcriptional target of MondoA, is a potent negative regulator of glucose uptake and utilization. Thus, TXNIP may inhibit cell growth by restricting substrate availability for macromolecular synthesis. To determine TXNIP's contribution to metabolic reprogramming, we examined MondoA and TXNIP as cells exit quiescence and enter G(1). Serum stimulation of quiescent immortal diploid fibroblasts resulted in an acute upregulation of glucose uptake and glycolysis coinciding with downregulation of TXNIP expression. Ectopic expression of either MondoA or TXNIP restricted cell growth by blocking glucose uptake. Mechanistically, Ras-MAPK and PI3K/Akt signaling inhibit TXNIP translation and MondoA-dependent TXNIP transcription, respectively. We propose that the coordinated downregulation of MondoA transcriptional activity at the TXNIP promoter and inhibition of TXNIP translation are key components of metabolic reprogramming required for cells to exit quiescence.
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Affiliation(s)
- Marc G Elgort
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
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Masutani H, Yoshihara E, Masaki S, Chen Z, Yodoi J. Thioredoxin binding protein (TBP)-2/Txnip and α-arrestin proteins in cancer and diabetes mellitus. J Clin Biochem Nutr 2011; 50:23-34. [PMID: 22247597 PMCID: PMC3246179 DOI: 10.3164/jcbn.11-36sr] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 05/05/2011] [Indexed: 01/05/2023] Open
Abstract
Thioredoxin binding protein -2/ thioredoxin interacting protein is an α-arrestin protein that has attracted much attention as a multifunctional regulator. Thioredoxin binding protein -2 expression is downregulated in tumor cells and the level of thioredoxin binding protein is correlated with clinical stage of cancer. Mice with mutations or knockout of the thioredoxin binding protein -2 gene are much more susceptible to carcinogenesis than wild-type mice, indicating a role for thioredoxin binding protein -2 in cancer suppression. Studies have also revealed roles for thioredoxin binding protein -2 in metabolic control. Enhancement of thioredoxin binding protein -2 expression causes impairment of insulin sensitivity and glucose-induced insulin secretion, and β-cell apoptosis. These changes are important characteristics of type 2 diabetes mellitus. Thioredoxin binding protein -2 regulates transcription of metabolic regulating genes. Thioredoxin binding protein -2-like inducible membrane protein/ arrestin domain containing 3 regulates endocytosis of receptors such as the β(2)-adrenergic receptor. The α-arrestin family possesses PPXY motifs and may function as an adaptor/scaffold for NEDD family ubiquitin ligases. Elucidation of the molecular mechanisms of α-arrestin proteins would provide a new pharmacological basis for developing approaches against cancer and type 2 diabetes mellitus.
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Affiliation(s)
- Hiroshi Masutani
- Institute for Virus Research, Graduate School of Biostudies, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo, Kyoto 606-8507, Japan
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Abstract
Nutrient excess in obesity and diabetes is emerging as a common putative cause for multiple deleterious effects across diverse cell types, responsible for a variety of metabolic dysfunctions. The hypothalamus is acknowledged as an important regulator of whole-body energy homeostasis, through both detection of nutrient availability and coordination of effectors that determine nutrient intake and utilization, thus preventing cellular and whole-body nutrient excess. However, the mechanisms underlying hypothalamic nutrient detection and its impact on peripheral nutrient utilization remain poorly understood. Recent data suggest a role for thioredoxin-interacting protein (TXNIP) as a molecular nutrient sensor important in the regulation of energy metabolism, but the role of hypothalamic TXNIP in the regulation of energy balance has not been evaluated. Here we show in mice that TXNIP is expressed in nutrient-sensing neurons of the mediobasal hypothalamus, responds to hormonal and nutrient signals, and regulates adipose tissue metabolism, fuel partitioning, and glucose homeostasis. Hypothalamic expression of TXNIP is induced by acute nutrient excess and in mouse models of obesity and diabetes, and downregulation of mediobasal hypothalamic TXNIP expression prevents diet-induced obesity and insulin resistance. Thus, mediobasal hypothalamic TXNIP plays a critical role in nutrient sensing and the regulation of fuel utilization.
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Chutkow WA, Lee RT. Thioredoxin regulates adipogenesis through thioredoxin-interacting protein (Txnip) protein stability. J Biol Chem 2011; 286:29139-29145. [PMID: 21705327 DOI: 10.1074/jbc.m111.267666] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Txnip (thioredoxin-interacting protein) is a critical mediator of metabolism and adipogenesis in vivo. The mechanisms of action of Txnip are believed to operate at least in part by inhibiting the redox signaling functions of thioredoxin. We tested here whether Txnip suppressed adipogenesis by inhibiting thioredoxin and discovered a reversal of roles; Txnip inhibits adipogenesis directly, and thioredoxin binding regulates Txnip by enhancing Txnip protein stability. Unlike Txnip, a Txnip mutant that cannot bind thioredoxin (C247S) did not prevent adipocyte differentiation, but was degraded more quickly by proteasomal targeting. Finding that endogenous Txnip protein is also rapidly degraded at the onset of adipogenesis suggested that Txnip degradation is required for adipocyte differentiation. Thioredoxin overexpression stabilized Txnip protein levels to inhibit adipogenesis, and adipogenic stimulants such as insulin promoted Txnip-thioredoxin dissociation to the more labile free Txnip state. As an α-arrestin protein, Txnip has two C-terminal tail PPXY motifs that mediate E3 ubiquitin ligase binding and Txnip protein stability. Mutating the PPXY motifs prevented Txnip degradation, even when thioredoxin binding was lost, and restored the ability of C247S Txnip to inhibit adipogenesis. These studies present a novel reconsideration of Txnip-thioredoxin signaling by showing that thioredoxin regulates the intrinsic function of Txnip as an inhibitor of adipogenesis through protein stabilization.
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Affiliation(s)
- William A Chutkow
- Harvard Stem Cell Institute and the Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115 and; Veterans Healthcare System, West Roxbury, Massachusetts 02132.
| | - Richard T Lee
- Harvard Stem Cell Institute and the Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115 and
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Polekhina G, Ascher DB, Kok SF, Waltham M. Crystallization and preliminary X-ray analysis of the N-terminal domain of human thioredoxin-interacting protein. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:613-7. [PMID: 21543874 PMCID: PMC3087653 DOI: 10.1107/s1744309111010347] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Accepted: 03/18/2011] [Indexed: 11/10/2022]
Abstract
Thioredoxin-interacting protein (TXNIP) is a negative regulator of thioredoxin and its roles in the pathologies of diabetes and cardiovascular diseases have marked it out as a potential drug target. Expression of TXNIP is robustly induced under various stress conditions such as high glucose, heat shock, UV, H(2)O(2) and mechanical stress amongst others. Elevated levels of TXNIP result in the sequestration and inactivation of thioredoxin, leading to cellular oxidative stress. For some time, this was the only known function of TXNIP; however, more recently the protein has been shown to play a role in regulation of glucose uptake and activation of the inflammasome. Based on the primary sequence, TXNIP is remotely related to β-arrestins, which include the visual arrestins. TXNIP has thus been classified as a member of the α-arrestin family, which to date includes five other members. None of the other α-arrestins are known to interact with thioredoxin, although curiously one has been implicated in glucose uptake. In order to gain insight into the structure-function relationships of the α-arrestin protein family, and particularly that of TXNIP, the N-terminal domain of TXNIP has been crystallized. The crystals belonged to a monoclinic space group and diffracted to 3 Å resolution using synchrotron radiation.
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Affiliation(s)
- Galina Polekhina
- Structural Biology, Monash Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton, Victoria 3168, Australia.
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Andres AM, Ratliff EP, Sachithanantham S, Hui ST. Diminished AMPK signaling response to fasting in thioredoxin-interacting protein knockout mice. FEBS Lett 2011; 585:1223-30. [PMID: 21439280 DOI: 10.1016/j.febslet.2011.03.042] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/07/2011] [Accepted: 03/18/2011] [Indexed: 01/11/2023]
Abstract
Thioredoxin-interacting protein (Txnip) knockout (TKO) mice exhibit impaired response to fasting. Herein, we showed that activation of adenine monophosphate-activated protein kinase and cellular AMP levels were diminished in the heart and soleus muscle but not in gastrocnemius muscle of fasting TKO mice. Similarly, glycogen content in fasted TKO mice was increased in oxidative muscles but was not different in glycolytic muscles. These data suggest Txnip deficiency has a higher impact on oxidative muscle than glycolytic muscles and provide new insights into the metabolic role of Txnip.
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Affiliation(s)
- Allen M Andres
- Department of Biology, BioScience Center, San Diego State University, San Diego, CA 92182, USA
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