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Vanweert F, Neinast M, Tapia EE, van de Weijer T, Hoeks J, Schrauwen-Hinderling VB, Blair MC, Bornstein MR, Hesselink MKC, Schrauwen P, Arany Z, Phielix E. A randomized placebo-controlled clinical trial for pharmacological activation of BCAA catabolism in patients with type 2 diabetes. Nat Commun 2022; 13:3508. [PMID: 35717342 PMCID: PMC9206682 DOI: 10.1038/s41467-022-31249-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 06/06/2022] [Indexed: 01/07/2023] Open
Abstract
Elevations in plasma branched-chain amino acid (BCAA) levels associate with insulin resistance and type 2 diabetes (T2D). Pre-clinical models suggest that lowering BCAA levels improve glucose tolerance, but data in humans are lacking. Here, we used sodium phenylbutyrate (NaPB), an accelerator of BCAA catabolism, as tool to lower plasma BCAA levels in patients with T2D, and evaluate its effect on metabolic health. This trial (NetherlandsTrialRegister: NTR7426) had a randomized, placebo-controlled, double-blind cross-over design and was performed in the Maastricht University Medical Center (MUMC+), the Netherlands, between February 2019 and February 2020. Patients were eligible for the trial if they were 40-75years, BMI of 25-38 kg/m², relatively well-controlled T2D (HbA1C < 8.5%) and treated with oral glucose-lowering medication. Eighteen participants were randomly assigned to receive either NaPB 4.8 g/m²/day and placebo for 2 weeks via controlled randomization and sixteen participants completed the study. The primary outcome was peripheral insulin sensitivity. Secondary outcomes were ex vivo muscle mitochondrial oxidative capacity, substrate oxidation and ectopic fat accumulation. Fasting blood samples were collected to determine levels of BCAA, their catabolic intermediates, insulin, triglycerides, free fatty acids (FFA) and glucose. NaPB led to a robust 27% improvement in peripheral insulin sensitivity compared to placebo (ΔRd:13.2 ± 1.8 vs. 9.6 ± 1.8 µmol/kg/min, p = 0.02). This was paralleled by an improvement in pyruvate-driven muscle mitochondrial oxidative capacity and whole-body insulin-stimulated carbohydrate oxidation, and a reduction in plasma BCAA and glucose levels. No effects were observed on levels of insulin, triglycerides and FFA, neither did fat accumulation in muscle and liver change. No adverse events were reported. These data establish the proof-of-concept in humans that modulating the BCAA oxidative pathway may represent a potential treatment strategy for patients with T2D.
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Affiliation(s)
- Froukje Vanweert
- grid.5012.60000 0001 0481 6099Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, 6229 ER The Netherlands
| | - Michael Neinast
- grid.25879.310000 0004 1936 8972Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA 19104 USA
| | - Edmundo Erazo Tapia
- grid.5012.60000 0001 0481 6099Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, 6229 ER The Netherlands
| | - Tineke van de Weijer
- grid.5012.60000 0001 0481 6099Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, 6229 ER The Netherlands ,grid.412966.e0000 0004 0480 1382Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, 6229 ER The Netherlands
| | - Joris Hoeks
- grid.5012.60000 0001 0481 6099Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, 6229 ER The Netherlands
| | - Vera B. Schrauwen-Hinderling
- grid.5012.60000 0001 0481 6099Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, 6229 ER The Netherlands ,grid.412966.e0000 0004 0480 1382Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, 6229 ER The Netherlands
| | - Megan C. Blair
- grid.25879.310000 0004 1936 8972Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA 19104 USA
| | - Marc R. Bornstein
- grid.25879.310000 0004 1936 8972Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA 19104 USA
| | - Matthijs K. C. Hesselink
- grid.5012.60000 0001 0481 6099Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, 6229 ER The Netherlands
| | - Patrick Schrauwen
- grid.5012.60000 0001 0481 6099Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, 6229 ER The Netherlands
| | - Zoltan Arany
- grid.25879.310000 0004 1936 8972Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA 19104 USA
| | - Esther Phielix
- grid.5012.60000 0001 0481 6099Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, 6229 ER The Netherlands
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Rossmeislová L, Gojda J, Smolková K. Pancreatic cancer: branched-chain amino acids as putative key metabolic regulators? Cancer Metastasis Rev 2021; 40:1115-1139. [PMID: 34962613 DOI: 10.1007/s10555-021-10016-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/18/2021] [Indexed: 02/06/2023]
Abstract
Branched-chain amino acids (BCAA) are essential amino acids utilized in anabolic and catabolic metabolism. While extensively studied in obesity and diabetes, recent evidence suggests an important role for BCAA metabolism in cancer. Elevated plasma levels of BCAA are associated with an increased risk of developing pancreatic cancer, namely pancreatic ductal adenocarcinoma (PDAC), a tumor with one of the highest 1-year mortality rates. The dreadful prognosis for PDAC patients could be attributable also to the early and frequent development of cancer cachexia, a fatal host metabolic reprogramming leading to muscle and adipose wasting. We propose that BCAA dysmetabolism is a unifying component of several pathological conditions, i.e., obesity, insulin resistance, and PDAC. These conditions are mutually dependent since PDAC ranks among cancers tightly associated with obesity and insulin resistance. It is also well-established that PDAC itself can trigger insulin resistance and new-onset diabetes. However, the exact link between BCAA metabolism, development of PDAC, and tissue wasting is still unclear. Although tissue-specific intracellular and systemic metabolism of BCAA is being intensively studied, unresolved questions related to PDAC and cancer cachexia remain, namely, whether elevated circulating BCAA contribute to PDAC etiology, what is the biological background of BCAA elevation, and what is the role of adipose tissue relative to BCAA metabolism during cancer cachexia. To cover those issues, we provide our view on BCAA metabolism at the intracellular, tissue, and whole-body level, with special emphasis on different metabolic links to BCAA intermediates and the role of insulin in substrate handling.
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Affiliation(s)
- Lenka Rossmeislová
- Department of Pathophysiology, Center for Research On Nutrition, Metabolism, and Diabetes, Third Faculty of Medicine, Charles University, Prague, Czech Republic
- Franco-Czech Laboratory for Clinical Research On Obesity, Third Faculty of Medicine, Prague, Czech Republic
| | - Jan Gojda
- Franco-Czech Laboratory for Clinical Research On Obesity, Third Faculty of Medicine, Prague, Czech Republic
- Department of Internal Medicine, Královské Vinohrady University Hospital and Third Faculty of Medicine, Prague, Czech Republic
| | - Katarína Smolková
- Laboratory of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
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3
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Free-amino acid metabolic profiling of visceral adipose tissue from obese subjects. Amino Acids 2020; 52:1125-1137. [PMID: 32757125 DOI: 10.1007/s00726-020-02877-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 07/26/2020] [Indexed: 12/21/2022]
Abstract
Interest in adipose tissue pathophysiology and biochemistry have expanded considerably in the past two decades due to the ever increasing and alarming rates of global obesity and its critical outcome defined as metabolic syndrome (MS). This obesity-linked systemic dysfunction generates high risk factors of developing perilous diseases like type 2 diabetes, cardiovascular disease or cancer. Amino acids could play a crucial role in the pathophysiology of the MS onset. Focus of this study was to fully characterize amino acids metabolome modulations in visceral adipose tissues (VAT) from three adult cohorts: (i) obese patients (BMI 43-48) with metabolic syndrome (PO), (ii) obese subjects metabolically well (O), and (iii) non obese individuals (H). 128 metabolites identified as 20 protein amino acids, 85 related compounds and 13 dipeptides were measured by ultrahigh performance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) and gas chromatography-/mass spectrometry GC/MS, in visceral fat samples from a total of 53 patients. Our analysis indicates a probable enhanced BCAA (leucine, isoleucine, valine) degradation in both VAT from O and PO subjects, while levels of their oxidation products are increased. Also PO and O VAT samples were characterized by: elevated levels of kynurenine, a catabolic product of tryptophan and precursor of diabetogenic substances, a significant increase of cysteine sulfinic acid levels, a decrease of 1-methylhistidine, and an up regulating trend of 3-methylhistidine levels. We hope this profiling can aid in novel clinical strategies development against the progression from obesity to metabolic syndrome.
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Lian K, Guo X, Wang Q, Liu Y, Wang RT, Gao C, Li CY, Li CX, Tao L. PP2Cm overexpression alleviates MI/R injury mediated by a BCAA catabolism defect and oxidative stress in diabetic mice. Eur J Pharmacol 2019; 866:172796. [PMID: 31738932 DOI: 10.1016/j.ejphar.2019.172796] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 11/08/2019] [Accepted: 11/14/2019] [Indexed: 12/31/2022]
Abstract
Diabetic patients are sensitive to myocardial ischemia-reperfusion (MI/R) injury. During diabetes, branched-chain amino acid (BCAA) catabolism is defective and mitochondrial phosphatase 2C (PP2Cm) expression is reduced. This study aims to elucidate the relationship between PP2Cm downregulation and BCAA catabolism defect in diabetic mice against MI/R injury. PP2Cm was significantly downregulated in hearts of diabetic mice. The cardiac function was improved and the myocardial infarct size and apoptosis were decreased in diabetic mice overexpressing PP2Cm after MI/R. In diabetic mice, the cardiac BCAA and its metabolites branched-chain keto-acids (BCKA) levels, and p-BCKDE1α (E1 subunit of BCKA dehydrogenase)/BCKDE1α ratio were increased while the BCKD activity was decreased. Treatment of diabetic mice subjected to MI/R injury with BT2, a BCKD kinase (BDK) inhibitor, alleviated the BCAA catabolism defect, and improved the cardiac function alongside reduced apoptosis. PP2Cm overexpression alleviated the BCAA catabolism defect and MI/R injury. Similarly, MnTBAP ameliorated the oxidative stress and MI/R injury. BCKA treatment of H9C2 cells under simulated ischemia/reperfusion (SI/R) injury significantly decreased cell viability and increased LDH release and apoptosis. These effects were alleviated by BT2 and MnTBAP treatments. These results suggested that PP2Cm directly mediates the BCAA catabolism defect and oxidative stress observed after MI/R in diabetes. Overexpression of PP2Cm alleviates MI/R injury by reducing the catabolism of BCAA and oxidative stress.
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Affiliation(s)
- Kun Lian
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Xiong Guo
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Qin Wang
- Department of Pharmacogenomics, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Yi Liu
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Ru-Tao Wang
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Chao Gao
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Cong-Ye Li
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Cheng-Xiang Li
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China.
| | - Ling Tao
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China.
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Wang J, Liu Y, Lian K, Shentu X, Fang J, Shao J, Chen M, Wang Y, Zhou M, Sun H. BCAA Catabolic Defect Alters Glucose Metabolism in Lean Mice. Front Physiol 2019; 10:1140. [PMID: 31551816 PMCID: PMC6738029 DOI: 10.3389/fphys.2019.01140] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/20/2019] [Indexed: 01/01/2023] Open
Abstract
Recent studies show branched-chain amino acid (BCAA) catabolic pathway is defective in obese animals and humans, contributing to the pathogenesis of insulin resistance and diabetes. However, in the context of obesity, various processes including the dysfunctional lipid metabolism can affect insulin sensitivity and glycemic regulation. It remains unclear how BCAA catabolic defect may exert direct impacts on glucose metabolism without the disturbance of obesity. The current study characterized the glucose metabolism in lean mice in which the genetic deletion of PP2Cm leads to moderate BCAA catabolic defect. Interestingly, compared to the wildtype control, lean PP2Cm deficient mice showed enhanced insulin sensitivity and glucose tolerance, lower body weight, and the preference for carbohydrate over lipids utilization. Metabolomics profiling of plasma and tissues revealed significantly different metabolic patterns in the PP2Cm deficient mice, featured by the marked alterations in glucose metabolic processes, including gluconeogenesis/glycolysis, glycogen metabolism, and tricarboxylic acid cycle. The metabolic changes of glucose were predominantly observed in liver but not skeletal muscle or white adipose tissue. The elevated branched-chain keto acids (BCKAs) resulted from the BCAA catabolic defect may play a critical role in regulating the expression of key regulators of glucose metabolic processes and the activity of respiratory Complex II/succinate dehydrogenase in TCA cycle. Together, these results show BCAA catabolic defect significantly alters glucose metabolism in lean mice with some impacts different or even opposite from those in obese mice, highlighting the critical role of BCAA catabolism in glycemic regulation and the complex interplay between macronutrients in lean and obese animals.
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Affiliation(s)
- Ji Wang
- Department of Pathophysiology, Hongqiao International Institute of Medicine, Tongren Hospital, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yunxia Liu
- Department of Pathophysiology, Hongqiao International Institute of Medicine, Tongren Hospital, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kun Lian
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Xinyi Shentu
- Department of Pathophysiology, Hongqiao International Institute of Medicine, Tongren Hospital, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Junwei Fang
- School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jing Shao
- Department of Pathophysiology, Hongqiao International Institute of Medicine, Tongren Hospital, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mengping Chen
- Department of Pathophysiology, Hongqiao International Institute of Medicine, Tongren Hospital, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yibin Wang
- Departments of Anesthesiology, Medicine and Physiology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA, United States
| | - Meiyi Zhou
- Department of Pathophysiology, Hongqiao International Institute of Medicine, Tongren Hospital, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haipeng Sun
- Department of Pathophysiology, Hongqiao International Institute of Medicine, Tongren Hospital, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Zhou M, Shao J, Wu CY, Shu L, Dong W, Liu Y, Chen M, Wynn RM, Wang J, Wang J, Gui WJ, Qi X, Lusis AJ, Li Z, Wang W, Ning G, Yang X, Chuang DT, Wang Y, Sun H. Targeting BCAA Catabolism to Treat Obesity-Associated Insulin Resistance. Diabetes 2019; 68:1730-1746. [PMID: 31167878 PMCID: PMC6702639 DOI: 10.2337/db18-0927] [Citation(s) in RCA: 179] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 05/29/2019] [Indexed: 12/12/2022]
Abstract
Recent studies implicate a strong association between elevated plasma branched-chain amino acids (BCAAs) and insulin resistance (IR). However, a causal relationship and whether interrupted BCAA homeostasis can serve as a therapeutic target for diabetes remain to be established experimentally. In this study, unbiased integrative pathway analyses identified a unique genetic link between obesity-associated IR and BCAA catabolic gene expression at the pathway level in human and mouse populations. In genetically obese (ob/ob) mice, rate-limiting branched-chain α-keto acid (BCKA) dehydrogenase deficiency (i.e., BCAA and BCKA accumulation), a metabolic feature, accompanied the systemic suppression of BCAA catabolic genes. Restoring BCAA catabolic flux with a pharmacological inhibitor of BCKA dehydrogenase kinase (BCKDK) ( a suppressor of BCKA dehydrogenase) reduced the abundance of BCAA and BCKA and markedly attenuated IR in ob/ob mice. Similar outcomes were achieved by reducing protein (and thus BCAA) intake, whereas increasing BCAA intake did the opposite; this corroborates the pathogenic roles of BCAAs and BCKAs in IR in ob/ob mice. Like BCAAs, BCKAs also suppressed insulin signaling via activation of mammalian target of rapamycin complex 1. Finally, the small-molecule BCKDK inhibitor significantly attenuated IR in high-fat diet-induced obese mice. Collectively, these data demonstrate a pivotal causal role of a BCAA catabolic defect and elevated abundance of BCAAs and BCKAs in obesity-associated IR and provide proof-of-concept evidence for the therapeutic validity of manipulating BCAA metabolism for treating diabetes.
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Affiliation(s)
- Meiyi Zhou
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jing Shao
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Cheng-Yang Wu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Le Shu
- Department of Integrative Biology and Physiology, University of California at Los Angeles, Los Angeles, CA
| | - Weibing Dong
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yunxia Liu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mengping Chen
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - R Max Wynn
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jiqiu Wang
- Department of Endocrinology and Metabolism, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ji Wang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wen-Jun Gui
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Xiangbing Qi
- Chemistry Center, National Institute of Biological Science, Beijing, China
| | - Aldons J Lusis
- Departments of Medicine, Microbiology, and Human Genetics, University of California at Los Angeles, Los Angeles, CA
| | - Zhaoping Li
- Department of Clinical Nutrition, University of California at Los Angeles, Los Angeles, CA
| | - Weiqing Wang
- Department of Endocrinology and Metabolism, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Guang Ning
- Department of Endocrinology and Metabolism, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xia Yang
- Department of Integrative Biology and Physiology, University of California at Los Angeles, Los Angeles, CA
| | - David T Chuang
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Yibin Wang
- Departments of Anesthesiology, Medicine, and Physiology, University of California at Los Angeles, Los Angeles, CA
| | - Haipeng Sun
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Departments of Anesthesiology, Medicine, and Physiology, University of California at Los Angeles, Los Angeles, CA
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Abstract
The cause of insulin resistance in obesity and type 2 diabetes mellitus (T2DM) is not limited to impaired insulin signalling but also involves the complex interplay of multiple metabolic pathways. The analysis of large data sets generated by metabolomics and lipidomics has shed new light on the roles of metabolites such as lipids, amino acids and bile acids in modulating insulin sensitivity. Metabolites can regulate insulin sensitivity directly by modulating components of the insulin signalling pathway, such as insulin receptor substrates (IRSs) and AKT, and indirectly by altering the flux of substrates through multiple metabolic pathways, including lipogenesis, lipid oxidation, protein synthesis and degradation and hepatic gluconeogenesis. Moreover, the post-translational modification of proteins by metabolites and lipids, including acetylation and palmitoylation, can alter protein function. Furthermore, the role of the microbiota in regulating substrate metabolism and insulin sensitivity is unfolding. In this Review, we discuss the emerging roles of metabolites in the pathogenesis of insulin resistance and T2DM. A comprehensive understanding of the metabolic adaptations involved in insulin resistance may enable the identification of novel targets for improving insulin sensitivity and preventing, and treating, T2DM.
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Biswas D, Duffley L, Pulinilkunnil T. Role of branched‐chain amino acid–catabolizing enzymes in intertissue signaling, metabolic remodeling, and energy homeostasis. FASEB J 2019; 33:8711-8731. [DOI: 10.1096/fj.201802842rr] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Dipsikha Biswas
- Department of Biochemistry and Molecular Biology Faculty of Medicine Dalhousie Medicine New Brunswick Dalhousie University Saint John New Brunswick Canada
| | - Luke Duffley
- Department of Biochemistry and Molecular Biology Faculty of Medicine Dalhousie Medicine New Brunswick Dalhousie University Saint John New Brunswick Canada
| | - Thomas Pulinilkunnil
- Department of Biochemistry and Molecular Biology Faculty of Medicine Dalhousie Medicine New Brunswick Dalhousie University Saint John New Brunswick Canada
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A. R, Agrawal N, Kumar H, Kumar V. Emerging role of branched chain amino acids in metabolic disorders: A mechanistic review. PHARMANUTRITION 2018. [DOI: 10.1016/j.phanu.2018.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Shi T, Yan X, Qiao L, Li B, Cheng L, Pan Y, Jing J, Cao N, Liu W. MiR-330-5p negatively regulates ovine preadipocyte differentiation by targeting branched-chain aminotransferase 2. Anim Sci J 2018; 89:858-867. [DOI: 10.1111/asj.12995] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 01/10/2018] [Indexed: 02/06/2023]
Affiliation(s)
- Tao Shi
- College of Animal Science and Veterinary Medicine; Shanxi Agricultural University; Taigu China
| | - Xiaoru Yan
- College of Animal Science and Veterinary Medicine; Shanxi Agricultural University; Taigu China
| | - Liying Qiao
- College of Animal Science and Veterinary Medicine; Shanxi Agricultural University; Taigu China
| | - Baojun Li
- College of Animal Science and Veterinary Medicine; Shanxi Agricultural University; Taigu China
| | - Lifen Cheng
- Division of Animal and Poultry Breeding; Department of Agriculture of Shanxi Province; Taiyuan China
| | - Yangyang Pan
- College of Animal Science and Veterinary Medicine; Shanxi Agricultural University; Taigu China
| | - Jiongjie Jing
- College of Animal Science and Veterinary Medicine; Shanxi Agricultural University; Taigu China
| | - Ningxian Cao
- Division of Animal and Poultry Breeding; Department of Agriculture of Shanxi Province; Taiyuan China
| | - Wenzhong Liu
- College of Animal Science and Veterinary Medicine; Shanxi Agricultural University; Taigu China
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Goni L, Qi L, Cuervo M, Milagro FI, Saris WH, MacDonald IA, Langin D, Astrup A, Arner P, Oppert JM, Svendstrup M, Blaak EE, Sørensen TI, Hansen T, Martínez JA. Effect of the interaction between diet composition and the PPM1K genetic variant on insulin resistance and β cell function markers during weight loss: results from the Nutrient Gene Interactions in Human Obesity: implications for dietary guidelines (NUGENOB) randomized trial. Am J Clin Nutr 2017; 106:902-908. [PMID: 28768654 DOI: 10.3945/ajcn.117.156281] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/29/2017] [Indexed: 11/14/2022] Open
Abstract
Background: Circulating branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) have been shown to be associated with insulin resistance and diabetes risk. The common rs1440581 T allele in the protein phosphatase Mg2+/Mn2+ dependent 1K (PPM1K) gene has been related to elevated BCAA concentrations and risk of type 2 diabetes.Objective: In the present study, we tested whether dietary fat and carbohydrate intakes influenced the association between the rs1440581 PPM1K genetic variant and glucose-metabolism traits during weight loss.Design: The rs1440581 PPM1K genetic variant was genotyped in a total of 757 nondiabetic individuals who were randomly assigned to 1 of 2 energy-restricted diets that differed in macronutrient composition (low-fat diet: 20-25% fat, 15% protein, and 60-65% carbohydrate; high-fat diet: 40-45% fat, 15% protein, and 40-45% carbohydrate). The changes in fasting glucose, fasting insulin, insulin resistance (homeostasis model assessment of insulin resistance) and homeostasis model assessment of β cell function (HOMA-B) were measured after a mean ± SD weight loss of 6.8 ± 3.4 kg over 10 wk and analyzed according to the presence of the T allele of rs1440581.Results: The rs1440581 T allele was associated with a smaller improvement in glucose concentrations after the 10-wk dietary intervention (β ± SE: 0.05 ± 0.02 mg/dL; P = 0.03). In addition, significant gene-diet interactions were shown for the rs1440581 PPM1K genetic variant in relation to changes in insulin and HOMA-B (P-interaction = 0.006 and 0.002, respectively). In response to the high-fat diet, the T allele was associated with a higher reduction of insulin (β ± SE: -0.77 ± 0.40 μU/mL; P = 0.04) and HOMA-B (β ± SE: -13.2 ± 3.81; P = 0.003). An opposite effect was observed in the low-fat diet group, although in this group the T allele was marginally (P = 0.10) and not significantly (P = 0.24) associated with insulin and HOMA-B, respectively.Conclusion:PPM1K rs1440581 may affect changes in glucose metabolism during weight loss, and this effect is dependent on dietary fat and carbohydrate intakes. This trial was registered at controlled-trials.com as ISRCTN25867281.
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Affiliation(s)
- Leticia Goni
- Department of Nutrition, Food Sciences and Physiology, and.,Center for Nutrition Research, Faculty of Pharmacy and Nutrition, University of Navarra, Pamplona, Navarra, Spain
| | - Lu Qi
- Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA.,Departments of Nutrition and.,Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA.,Channing Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Marta Cuervo
- Department of Nutrition, Food Sciences and Physiology, and.,Center for Nutrition Research, Faculty of Pharmacy and Nutrition, University of Navarra, Pamplona, Navarra, Spain.,Biomedical Research Center Network in Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain.,Navarra Institute for Health Research, Pamplona, Navarra, Spain
| | - Fermín I Milagro
- Department of Nutrition, Food Sciences and Physiology, and.,Center for Nutrition Research, Faculty of Pharmacy and Nutrition, University of Navarra, Pamplona, Navarra, Spain.,Biomedical Research Center Network in Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain.,Navarra Institute for Health Research, Pamplona, Navarra, Spain
| | - Wim H Saris
- Department of Human Biology, School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, Netherlands
| | - Ian A MacDonald
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Dominique Langin
- National Institute of Health and Medical Research, UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.,University of Toulouse, UMR1048, Institute of Metabolic and Cardiovascular Diseases, Paul Sabatier University, Toulouse, France.,Laboratory of Clinical Biochemistry, Toulouse University Hospitals, Toulouse, France
| | - Arne Astrup
- Department of Nutrition, Exercise and Sports, and
| | - Peter Arner
- Department of Medicine, Karolinska Institute at Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Jean-Michel Oppert
- Department of Nutrition, Pitie-Salpetriere University Hospital; University Pierre et Marie Curie-Paris 6; Institute of Cardiometabolism and Nutrition; Center for Research on Human Nutrition Ile-de-France; Paris, France
| | - Mathilde Svendstrup
- Novo Nordisk Foundation Center for Basic Metabolic Research and.,Danish Diabetes Academy, Odense, Denmark; and
| | - Ellen E Blaak
- Department of Human Biology, School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, Netherlands
| | - Thorkild Ia Sørensen
- Department of Nutrition, Food Sciences and Physiology, and.,Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Epidemiology (formerly Institute of Preventive Medicine), Bispebjerg and Frederiksberg Hospitals, The Capital Region, Copenhagen, Denmark
| | - Torben Hansen
- Novo Nordisk Foundation Center for Basic Metabolic Research and
| | - J Alfredo Martínez
- Department of Nutrition, Food Sciences and Physiology, and .,Center for Nutrition Research, Faculty of Pharmacy and Nutrition, University of Navarra, Pamplona, Navarra, Spain.,Biomedical Research Center Network in Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain.,Navarra Institute for Health Research, Pamplona, Navarra, Spain
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12
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Yoon MS. The Emerging Role of Branched-Chain Amino Acids in Insulin Resistance and Metabolism. Nutrients 2016; 8:nu8070405. [PMID: 27376324 PMCID: PMC4963881 DOI: 10.3390/nu8070405] [Citation(s) in RCA: 264] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/01/2016] [Accepted: 06/27/2016] [Indexed: 12/12/2022] Open
Abstract
Insulin is required for maintenance of glucose homeostasis. Despite the importance of insulin sensitivity to metabolic health, the mechanisms that induce insulin resistance remain unclear. Branched-chain amino acids (BCAAs) belong to the essential amino acids, which are both direct and indirect nutrient signals. Even though BCAAs have been reported to improve metabolic health, an increased BCAA plasma level is associated with a high risk of metabolic disorder and future insulin resistance, or type 2 diabetes mellitus (T2DM). The activation of mammalian target of rapamycin complex 1 (mTORC1) by BCAAs has been suggested to cause insulin resistance. In addition, defective BCAA oxidative metabolism might occur in obesity, leading to a further accumulation of BCAAs and toxic intermediates. This review provides the current understanding of the mechanism of BCAA-induced mTORC1 activation, as well as the effect of mTOR activation on metabolic health in terms of insulin sensitivity. Furthermore, the effects of impaired BCAA metabolism will be discussed in detail.
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Affiliation(s)
- Mee-Sup Yoon
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon 406-840, Korea.
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13
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Branched-chain amino acid catabolism fuels adipocyte differentiation and lipogenesis. Nat Chem Biol 2015; 12:15-21. [PMID: 26571352 PMCID: PMC4684771 DOI: 10.1038/nchembio.1961] [Citation(s) in RCA: 285] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 10/07/2015] [Indexed: 12/29/2022]
Abstract
Adipose tissue plays important roles in regulating carbohydrate and lipid homeostasis, though less is known about the regulation of amino acid metabolism in adipocytes. Here we applied isotope tracing to pre–adipocytes and differentiated adipocytes to quantify the contributions of different substrates to tricarboxylic acid metabolism and lipogenesis. In contrast to proliferating cells that use glucose and glutamine for acetyl–coenzyme A (AcCoA) generation, differentiated adipocytes increased branched chain amino acid (BCAA) catabolic flux such that leucine and isoleucine from media and/or protein catabolism accounted for as much as 30% of lipogenic AcCoA pools. Medium cobalamin deficiency caused methylmalonic acid accumulation and odd–chain fatty acid synthesis. B12 supplementation reduced these metabolites and altered the balance of substrates entering mitochondria. Finally, inhibition of BCAA catabolism compromised adipogenesis. These results quantitatively highlight the contribution of BCAAs to adipocyte metabolism and suggest that BCAA catabolism plays a functional role in adipocyte differentiation.
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14
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Boulet MM, Chevrier G, Grenier-Larouche T, Pelletier M, Nadeau M, Scarpa J, Prehn C, Marette A, Adamski J, Tchernof A. Alterations of plasma metabolite profiles related to adipose tissue distribution and cardiometabolic risk. Am J Physiol Endocrinol Metab 2015; 309:E736-46. [PMID: 26306599 DOI: 10.1152/ajpendo.00231.2015] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 08/11/2015] [Indexed: 12/17/2022]
Abstract
Metabolomic profiling of obese individuals revealed altered concentrations of many metabolites, especially branched-chain amino acids (BCAA), possibly linked to altered adipose tissue BCAA catabolism. We tested the hypothesis that some features of this metabolite signature relate closely to visceral obesity and concomitant alterations in cardiometabolic risk factors. We also postulated that alterations in BCAA-catabolizing enzymes are predominant in visceral adipose tissue. Fifty-nine women (BMI 20-41 kg/m(2)) undergoing gynecologic surgery were recruited and characterized for overall and regional adiposity, blood metabolite levels using targeted metabolomics, and cardiometabolic risk factors. Adipose samples (visceral and subcutaneous) were obtained and used for gene expression and Western blot analyses. Obese women had significantly higher circulating BCAA and kynurenine/tryptophan (Kyn/Trp) ratio than lean or overweight women (P < 0.01). Principal component analysis confirmed that factors related to AA and the Kyn/Trp ratio were positively associated with BMI, fat mass, visceral or subcutaneous adipose tissue area, and subcutaneous adipocyte size (P ≤ 0.05). AA-related factor was positively associated with HOMA-IR (P ≤ 0.01). Factors reflecting glycerophospholipids and sphingolipids levels were mostly associated with altered blood lipid concentrations (P ≤ 0.05). Glutamate level was the strongest independent predictor of visceral adipose tissue area (r = 0.46, P < 0.001). Obese women had lower expression and protein levels of BCAA-catabolizing enzymes in visceral adipose tissue than overweight or lean women (P ≤ 0.05). We conclude that among metabolites altered in obesity plasma concentrations of BCAA and the Kyn/Trp ratio are closely related to increased adiposity. Alterations in expression and protein levels of BCAA-catabolizing enzymes are predominant in visceral adipose tissue.
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Affiliation(s)
- Marie Michèle Boulet
- Endocrinology and Nephrology, Centre Hospitalier Universitaire de Quebec, Quebec City, Canada; School of Nutrition, Laval University, Quebec City, Canada; Quebec Heart and Lung Institute, Quebec City, Canada
| | | | | | - Mélissa Pelletier
- Endocrinology and Nephrology, Centre Hospitalier Universitaire de Quebec, Quebec City, Canada
| | | | - Julia Scarpa
- Helmholtz Zentrum München, Institute of Experimental Genetics, Genome Analysis Center, Neuherberg, Germany
| | - Cornelia Prehn
- Helmholtz Zentrum München, Institute of Experimental Genetics, Genome Analysis Center, Neuherberg, Germany
| | - André Marette
- Quebec Heart and Lung Institute, Quebec City, Canada
| | - Jerzy Adamski
- Helmholtz Zentrum München, Institute of Experimental Genetics, Genome Analysis Center, Neuherberg, Germany; Lehrstuhl für Experimentelle Genetik, Technische Universität München, Freising-Weihenstephan, Germany; and German Center for Diabetes Research, Neuherberg, Germany
| | - André Tchernof
- Endocrinology and Nephrology, Centre Hospitalier Universitaire de Quebec, Quebec City, Canada; School of Nutrition, Laval University, Quebec City, Canada; Quebec Heart and Lung Institute, Quebec City, Canada;
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15
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Lynch CJ, Kimball SR, Xu Y, Salzberg AC, Kawasawa YI. Global deletion of BCATm increases expression of skeletal muscle genes associated with protein turnover. Physiol Genomics 2015; 47:569-80. [PMID: 26351290 DOI: 10.1152/physiolgenomics.00055.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/04/2015] [Indexed: 01/04/2023] Open
Abstract
Consumption of a protein-containing meal by a fasted animal promotes protein accretion in skeletal muscle, in part through leucine stimulation of protein synthesis and indirectly through repression of protein degradation mediated by its metabolite, α-ketoisocaproate. Mice lacking the mitochondrial branched-chain aminotransferase (BCATm/Bcat2), which interconverts leucine and α-ketoisocaproate, exhibit elevated protein turnover. Here, the transcriptomes of gastrocnemius muscle from BCATm knockout (KO) and wild-type mice were compared by next-generation RNA sequencing (RNA-Seq) to identify potential adaptations associated with their persistently altered nutrient signaling. Statistically significant changes in the abundance of 1,486/∼39,010 genes were identified. Bioinformatics analysis of the RNA-Seq data indicated that pathways involved in protein synthesis [eukaryotic initiation factor (eIF)-2, mammalian target of rapamycin, eIF4, and p70S6K pathways including 40S and 60S ribosomal proteins], protein breakdown (e.g., ubiquitin mediated), and muscle degeneration (apoptosis, atrophy, myopathy, and cell death) were upregulated. Also in agreement with our previous observations, the abundance of mRNAs associated with reduced body size, glycemia, plasma insulin, and lipid signaling pathways was altered in BCATm KO mice. Consistently, genes encoding anaerobic and/or oxidative metabolism of carbohydrate, fatty acids, and branched chain amino acids were modestly but systematically reduced. Although there was no indication that muscle fiber type was different between KO and wild-type mice, a difference in the abundance of mRNAs associated with a muscular dystrophy phenotype was observed, consistent with the published exercise intolerance of these mice. The results suggest transcriptional adaptations occur in BCATm KO mice that along with altered nutrient signaling may contribute to their previously reported protein turnover, metabolic and exercise phenotypes.
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Affiliation(s)
- Christopher J Lynch
- Department of Cellular and Molecular Physiology, College of Medicine, Penn State University, Hershey, Pennsylvania;
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, College of Medicine, Penn State University, Hershey, Pennsylvania
| | - Yuping Xu
- Department of Cellular and Molecular Physiology, College of Medicine, Penn State University, Hershey, Pennsylvania
| | - Anna C Salzberg
- The Institute for Personalized Medicine, College of Medicine, Penn State University, Hershey, Pennsylvania
| | - Yuka Imamura Kawasawa
- The Institute for Personalized Medicine, College of Medicine, Penn State University, Hershey, Pennsylvania; Department of Pharmacology, College of Medicine, Penn State University, Hershey, Pennsylvania; and Department of Biochemistry and Molecular Biology, College of Medicine, Penn State University, Hershey, Pennsylvania
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16
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Abstract
Branched-chain amino acids (BCAAs) are important nutrient signals that have direct and indirect effects. Frequently, BCAAs have been reported to mediate antiobesity effects, especially in rodent models. However, circulating levels of BCAAs tend to be increased in individuals with obesity and are associated with worse metabolic health and future insulin resistance or type 2 diabetes mellitus (T2DM). A hypothesized mechanism linking increased levels of BCAAs and T2DM involves leucine-mediated activation of the mammalian target of rapamycin complex 1 (mTORC1), which results in uncoupling of insulin signalling at an early stage. A BCAA dysmetabolism model proposes that the accumulation of mitotoxic metabolites (and not BCAAs per se) promotes β-cell mitochondrial dysfunction, stress signalling and apoptosis associated with T2DM. Alternatively, insulin resistance might promote aminoacidaemia by increasing the protein degradation that insulin normally suppresses, and/or by eliciting an impairment of efficient BCAA oxidative metabolism in some tissues. Whether and how impaired BCAA metabolism might occur in obesity is discussed in this Review. Research on the role of individual and model-dependent differences in BCAA metabolism is needed, as several genes (BCKDHA, PPM1K, IVD and KLF15) have been designated as candidate genes for obesity and/or T2DM in humans, and distinct phenotypes of tissue-specific branched chain ketoacid dehydrogenase complex activity have been detected in animal models of obesity and T2DM.
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Affiliation(s)
- Christopher J Lynch
- Cellular and Molecular Physiology Department, The Pennsylvania State University, 500 University Drive, MC-H166, Hershey, PA 17033, USA
| | - Sean H Adams
- Arkansas Children's Nutrition Center, and Department of Pediatrics, University of Arkansas for Medical Sciences, 15 Children's Way, Little Rock, AR 72202, USA
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17
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Olson KC, Chen G, Xu Y, Hajnal A, Lynch CJ. Alloisoleucine differentiates the branched-chain aminoacidemia of Zucker and dietary obese rats. Obesity (Silver Spring) 2014; 22:1212-5. [PMID: 24415721 PMCID: PMC4008669 DOI: 10.1002/oby.20691] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 01/02/2014] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Circulating branched-chain amino acids (BCAAs) are elevated in obesity and this has been linked to obesity comorbidities. However it is unclear how obesity affects alloisoleucine, a BCAA and pathognomonic marker of branched-chain keto acid dehydrogenase complex (BCKDC) disorders. It has been previously established that obese Zucker rats exhibit BCKDC impairments in fat and other tissues, whereas BCKDC impairments in adipose tissue of DIO rats are compensated by increased hepatic BCKDC activity. Therefore, alloisoleucine was investigated in these two obesity models. METHODS Amino acids were extracted from plasma and measured using ultra performance liquid chromatography mass spectrometry. RESULTS Plasma alloisoleucine was 238% higher in obese compared to lean Zucker rats. This elevation was greater than that of other BCAAs (107-124%). DIO rats had no significant change in alloisoleucine, despite elevations in other BCAAs (15-66%). CONCLUSIONS Alloisoleucine was elevated in obese Zucker but not DIO rats consistent with known global impairments of BCKDC in Zucker but not DIO rats. Cytotoxic branched-chain ketoacids (BCKAs) accumulate in genetic disorders affecting BCKDC. BCKAs increase reactive oxygen species, stress kinase activation, and mitochondrial dysfunction. Inasmuch as these factors underlie obesity comorbidities, it may important to identify obese individuals with elevated alloisoleucine.
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Affiliation(s)
- Kristine C. Olson
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA
| | - Gang Chen
- Department of Public Health Sciences, Penn State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA
- The Macromolecular Core Facility, Penn State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA
| | - Yuping Xu
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA
| | - Andras Hajnal
- Department of Neural and Behavioral Sciences, Penn State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA
| | - Christopher J. Lynch
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA
- Correspondence: Christopher J. Lynch, Ph.D., Dept. of Cellular & Molecular Physiology, Penn State College of Medicine. 500 University Drive, MC-H166, Hershey, PA 17033, USA, FAX: +1 717 531 7667,
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18
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Burrage LC, Nagamani SCS, Campeau PM, Lee BH. Branched-chain amino acid metabolism: from rare Mendelian diseases to more common disorders. Hum Mol Genet 2014; 23:R1-8. [PMID: 24651065 DOI: 10.1093/hmg/ddu123] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Branched-chain amino acid (BCAA) metabolism plays a central role in the pathophysiology of both rare inborn errors of metabolism and the more common multifactorial diseases. Although deficiency of the branched-chain ketoacid dehydrogenase (BCKDC) and associated elevations in the BCAAs and their ketoacids have been recognized as the cause of maple syrup urine disease (MSUD) for decades, treatment options for this disorder have been limited to dietary interventions. In recent years, the discovery of improved leucine tolerance after liver transplantation has resulted in a new therapeutic strategy for this disorder. Likewise, targeting the regulation of the BCKDC activity may be an alternative potential treatment strategy for MSUD. The regulation of the BCKDC by the branched-chain ketoacid dehydrogenase kinase has also been implicated in a new inborn error of metabolism characterized by autism, intellectual disability and seizures. Finally, there is a growing body of literature implicating BCAA metabolism in more common disorders such as the metabolic syndrome, cancer and hepatic disease. This review surveys the knowledge acquired on the topic over the past 50 years and focuses on recent developments in the field of BCAA metabolism.
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Affiliation(s)
- Lindsay C Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Sandesh C S Nagamani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Brendan H Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA Howard Hughes Medical Institute, Houston, TX 77030, USA
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Verbicaro T, Giovanini AF, Zielak JC, Baratto Filho F, Araujo MRD, Deliberador TM. Osteocalcin Immunohistochemical Expression During Repair of Critical-Sized Bone Defects Treated with Subcutaneous Adipose Tissue in Rat and Rabbit Animal Model. Braz Dent J 2013; 24:559-64. [DOI: 10.1590/0103-6440201302362] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 11/22/2013] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to evaluate the osteocalcin immunoexpression during the bone repair treated with subcutaneous adipose tissue in rats and rabbits. Fourteen rats and 14 rabbits were used in the study. A critical-sized calvarial defect was created in each animal. The animals were divided into 4 experimental groups: RC (rat control), RbC (rabbit control), RAT (rat adipose tissue), RbAT (rabbit adipose tissue). In the groups RC and RbC the defect was filled with a blood clot. In groups RAT and RbAT, the defect was filled with macerated subcutaneous adipose tissue. The euthanasia was performed at 30 days (RC and RAT) and 40 days (RbC and RbAT). Histological analysis and immunohistochemical analysis of osteocalcin protein expression were performed. Data were submitted to descriptive statistical analysis (mode). Osteocalcin immunoexpression was detected in the experimental models. Notwithstanding, RbAT showed higher positivity, especially in the adipocytes, than the group RAT group. In groups RC and RbC, the surgical wound was filled by collagen fibers. In Group RAT, the defect was composed by collagen fibers and adipocytes in the reparative sites. Similarly, in RbAT, the defect also was partially filled by collagen fibers and presence of adipocytes dispersed among the fibers. Additionally, chronic inflammatory process and areas of bone matrix deposition were observed. It may be concluded that in both animal models the adipose tissue demonstrated low osteogenic capacity. However, the rabbit animal model exhibited a more evident osteocalcin immunoexpression and a greater amount of newly formed bone matrix.
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