1
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Li C, Yang Q, Zhang L. Identification of putative allosteric inhibitors of BCKDK via virtual screening and biological evaluation. J Enzyme Inhib Med Chem 2024; 39:2290458. [PMID: 38059302 DOI: 10.1080/14756366.2023.2290458] [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: 06/24/2023] [Accepted: 11/21/2023] [Indexed: 12/08/2023] Open
Abstract
Abnormal accumulation of branched-chain amino acids (BCAAs) can lead to metabolic diseases and cancers. Branched-chain α-keto acid dehydrogenase kinase (BCKDK) is a key negative regulator of BCAA catabolism, and targeting BCKDK provides a promising therapeutic approach for diseases caused by BCAA accumulation. Here, we screened PPHN and POAB as novel putative allosteric inhibitors by integrating allosteric binding site prediction, large-scale ligand database virtual screening, and bioactivity evaluation assays. Both of them showed a high binding affinity to BCKDK, with Kd values of 3.9 μM and 1.86 μM, respectively. In vivo experiments, the inhibitors demonstrated superior kinase inhibitory activity and notable antiproliferative and proapoptotic effects on diverse cancer cells. Finally, bulk RNA-seq analysis revealed that PPHN and POAB suppressed cell growth through a range of signalling pathways. Taken together, our findings highlight two novel BCKDK inhibitors as potent therapeutic candidates for metabolic diseases and cancers associated with BCAA dysfunctional metabolism.
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Affiliation(s)
- Chunqiong Li
- Genomics Center, Chinese Institute for Brain Research, Beijing, China
| | - Quanjun Yang
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Li Zhang
- Genomics Center, Chinese Institute for Brain Research, Beijing, China
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2
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Zhang C, Huang H, Li C, Wei L, Wu J, Wang R, Huang S, Chen Q, Mo P, Yin Y, Chen J. Transcriptomics and UHPLC-QQQ-MS analyses reveal the dysregulation of branched chain amino acids metabolism in renal fibrotic rats. J Pharm Biomed Anal 2024; 245:116197. [PMID: 38723558 DOI: 10.1016/j.jpba.2024.116197] [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] [Received: 01/17/2024] [Revised: 04/16/2024] [Accepted: 05/02/2024] [Indexed: 05/23/2024]
Abstract
The dysregulated levels of branched chain amino acids (BCAA) contribute to renal fibrosis in chronic kidney disease (CKD), yet specific analysis of BCAA contents and how they are regulated still remain unclear. It is therefore of great scientific interest to understand BCAA catabolism in CKD and develop a sensitive method for simultaneous determination of individual BCAA and their metabolites branched chain α-ketoacids (BCKA). In this work, the important role of BCAA metabolism that drives renal fibrosis in the process of CKD was first revealed by using transcriptomics. The key target genes controlling BCAA metabolism were then validated, that is, mRNA levels of BCKDHA and BCKDHB, the regulating rate-limiting enzymes during BCAA metabolism were abnormally reduced by quantitative PCR (qPCR), and a similar drop-off trend of protein expression of BCKDH, HIBCH and MCCC2 that are closely related to BCAA metabolism was also confirmed by western blotting. Furthermore, we established a novel strategy that simultaneously determines 6 individual BCAA and BCKA in serum and tissue. The method based on dansylhydrazine derivatization and ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry (UHPLC-QQQ-MS) achieved to simultaneously determine the contents of BCAA and BCKA, which is efficient and stable. Compared with normal rats, levels of BCAA including leucine, isoleucine and valine in serum and kidney of CKD rats was decreased, while BCKA including α-ketoisocaproic acid, α-ketomethylvaleric acid and α-ketoisovaleric acid was increased. Together, these findings revealed the abnormality of BCAA metabolism in driving the course of kidney fibrosis and CKD. Our current study sheds new light on changes in BCAA metabolism during CKD, and may facilitate development of drugs to treat CKD and renal fibrosis.
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Affiliation(s)
- Chi Zhang
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China
| | - Haipiao Huang
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China
| | - Changhui Li
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China
| | - Lifang Wei
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China
| | - Jingru Wu
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China
| | - Rui Wang
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China
| | - Shiying Huang
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China
| | - Qiugu Chen
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China
| | - Pingli Mo
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China
| | - Yinghao Yin
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China
| | - Jianping Chen
- Shenzhen Key Laboratory of Hospital Chinese Medicine Preparation, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen 518033, China.
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3
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Fine KS, Wilkins JT, Sawicki KT. Circulating Branched Chain Amino Acids and Cardiometabolic Disease. J Am Heart Assoc 2024; 13:e031617. [PMID: 38497460 PMCID: PMC11179788 DOI: 10.1161/jaha.123.031617] [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] [Indexed: 03/19/2024]
Abstract
Branched chain amino acids (BCAAs) are essential for protein homeostasis, energy balance, and signaling pathways. Changes in BCAA homeostasis have emerged as pivotal contributors in the pathophysiology of several cardiometabolic diseases, including type 2 diabetes, obesity, hypertension, atherosclerotic cardiovascular disease, and heart failure. In this review, we provide a detailed overview of BCAA metabolism, focus on molecular mechanisms linking disrupted BCAA homeostasis with cardiometabolic disease, summarize the evidence from observational and interventional studies investigating associations between circulating BCAAs and cardiometabolic disease, and offer valuable insights into the potential for BCAA manipulation as a novel therapeutic strategy for cardiometabolic disease.
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Affiliation(s)
- Keenan S. Fine
- Northwestern University Feinberg School of MedicineChicagoILUSA
| | - John T. Wilkins
- Northwestern University Feinberg School of MedicineChicagoILUSA
- Division of Cardiology, Department of MedicineNorthwestern University Feinberg School of MedicineChicagoILUSA
| | - Konrad T. Sawicki
- Northwestern University Feinberg School of MedicineChicagoILUSA
- Division of Cardiology, Department of MedicineNorthwestern University Feinberg School of MedicineChicagoILUSA
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4
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Rivera CN, Smith CE, Draper LV, Kee ME, Cook NE, McGovern MR, Watne RM, Wommack AJ, Vaughan RA. The BCKDH kinase inhibitor BT2 promotes BCAA disposal and mitochondrial proton leak in both insulin-sensitive and insulin-resistant C2C12 myotubes. J Cell Biochem 2024; 125:e30520. [PMID: 38226684 DOI: 10.1002/jcb.30520] [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: 05/27/2023] [Revised: 11/29/2023] [Accepted: 12/21/2023] [Indexed: 01/17/2024]
Abstract
Elevated circulating branched-chain amino acids (BCAAs) have been correlated with the severity of insulin resistance, leading to recent investigations that stimulate BCAA metabolism for the potential benefit of metabolic diseases. BT2 (3,6-dichlorobenzo[b]thiophene-2-carboxylic acid), an inhibitor of branched-chain ketoacid dehydrogenase kinase, promotes BCAA metabolism by enhancing BCKDH complex activity. The purpose of this report was to investigate the effects of BT2 on mitochondrial and glycolytic metabolism, insulin sensitivity, and de novo lipogenesis both with and without insulin resistance. C2C12 myotubes were treated with or without low or moderate levels of BT2 with or without insulin resistance. Western blot and quantitative real-time polymerase chain reaction were used to assess protein and gene expression, respectively. Mitochondrial, nuclei, and lipid content were measured using fluorescent staining and microscopy. Cell metabolism was assessed via oxygen consumption and extracellular acidification rate. Liquid chromatography-mass spectrometry was used to quantify BCAA media content. BT2 treatment consistently promoted mitochondrial uncoupling following 24-h treatment, which occurred largely independent of changes in expressional profiles associated with mitochondrial biogenesis, mitochondrial dynamics, BCAA catabolism, insulin sensitivity, or lipogenesis. Acute metabolic studies revealed a significant and dose-dependent effect of BT2 on mitochondrial proton leak, suggesting BT2 functions as a small-molecule uncoupler. Additionally, BT2 treatment consistently and dose-dependently reduced extracellular BCAA levels without altering expression of BCAA catabolic enzymes or pBCKDHa activation. BT2 appears to act as a small-molecule mitochondrial uncoupler that promotes BCAA utilization, though the interplay between these two observations requires further investigation.
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Affiliation(s)
- Caroline N Rivera
- Department of Health and Human Performance, High Point University, High Point, North Carolina, USA
| | - Carly E Smith
- Department of Health and Human Performance, High Point University, High Point, North Carolina, USA
| | - Lillian V Draper
- Department of Health and Human Performance, High Point University, High Point, North Carolina, USA
| | - Madison E Kee
- Department of Health and Human Performance, High Point University, High Point, North Carolina, USA
| | - Norah E Cook
- Department of Health and Human Performance, High Point University, High Point, North Carolina, USA
| | - Macey R McGovern
- Department of Health and Human Performance, High Point University, High Point, North Carolina, USA
| | - Rachel M Watne
- Department of Chemistry, High Point University, High Point, North Carolina, USA
| | - Andrew J Wommack
- Department of Chemistry, High Point University, High Point, North Carolina, USA
| | - Roger A Vaughan
- Department of Health and Human Performance, High Point University, High Point, North Carolina, USA
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Chen L, Zhang H, Chi M, Wang Y, Zhu X, Han L, Xin B, Gan R, Tu Y, Sun X, Lu J, Li J, Huang J, Zhang J, Han Y, Guo C, Yang Q. Bckdk-Mediated Branch Chain Amino Acid Metabolism Reprogramming Contributes to Muscle Atrophy during Cancer Cachexia. Mol Nutr Food Res 2023:e2300577. [PMID: 38150655 DOI: 10.1002/mnfr.202300577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 10/07/2023] [Indexed: 12/29/2023]
Abstract
SCOPE Branched chain amino acids (BCAAs) are essential amino acids and important nutrient signals for energy and protein supplementation. The study uses muscle-specific branched-chain α-keto acid dehydrogenase kinase (Bckdk) conditional knockout (cKO) mice to reveal the contribution of BCAA metabolic dysfunction to muscle wasting. METHOD AND RESULTS Muscle-specific Bckdk-cKO mice are generated through crossbreeding of Bckdkf/f mice with Myf5Cre mice. Lewis lung cancer (LLC) tumor transplantation is used to establish the cancer cachexia model. The occurrence of cancer cachexia is accelerated in the muscle-specific Bckdk-cKO mice after bearing LLC tumor. Wasting skeletal muscle is characterized by increased protein ubiquitination degradation and impaired protein synthesis. The wasting muscle gastrocnemius is mechanized as a distinct BCAA metabolic dysfunction. Based on the atrophy phenotype resulting from BCAA metabolism dysfunction, the optimized BCAA supplementation improves the survival of cancer cachexia in muscle-specific Bckdk-cKO mice bearing LLC tumors, and improves the occurrence of cancer cachexia. The mechanism of BCAA supplementation on muscle mass preservation is based on the promotion of protein synthesis and the inhibition of protein ubiquitination degradation. CONCLUSIONS Dysfunctional BCAA metabolism contributes to the inhibition of protein synthesis and increases protein degradation in the cancer cachexia model of muscle-specific Bckdk-cKO mice bearing LLC tumors. The reprogramming of BCAA catabolism exerts therapeutic effects by stimulating protein synthesis and inhibiting protein degradation in skeletal muscle.
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Affiliation(s)
- Li Chen
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Hong Zhang
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Mengyi Chi
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Yaxian Wang
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Xinting Zhu
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Leng Han
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Bo Xin
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Run Gan
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Yixin Tu
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Xipeng Sun
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Jin Lu
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Jie Li
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Jinlu Huang
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Jianping Zhang
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Yonglong Han
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Cheng Guo
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Quanjun Yang
- Department of Pharmacy, Shanghai Sixth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
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Mangogna A, Di Girolamo FG, Fiotti N, Vinci P, Landolfo M, Mearelli F, Biolo G. High-protein diet with excess leucine prevents inactivity-induced insulin resistance in women. Clin Nutr 2023; 42:2578-2587. [PMID: 37972527 DOI: 10.1016/j.clnu.2023.10.028] [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] [Received: 02/03/2023] [Revised: 09/18/2023] [Accepted: 10/29/2023] [Indexed: 11/19/2023]
Abstract
BACKGROUND AND AIMS Muscle inactivity leads to muscle atrophy and insulin resistance. The branched-chain amino acid (BCAA) leucine interacts with the insulin signaling pathway to modulate glucose metabolism. We have tested the ability of a high-protein BCAA-enriched diet to prevent insulin resistance during long-term bed rest (BR). METHODS Stable isotopes were infused to determine glucose and protein kinetics in the postabsorptive state and during a hyperinsulinemic-euglycemic clamp in combination with amino acid infusion (Clamp + AA) before and at the end of 60 days of BR in two groups of healthy, young women receiving eucaloric diets containing 1 g of protein/kg per day (n = 8) or 1.45 g of protein/kg per day enriched with 0.15 g/kg per day of BCAAs (leucine/valine/isoleucine = 2/1/1) (n = 8). Body composition was determined by Dual X-ray Absorptiometry. RESULTS BR decreased lean body mass by 7.6 ± 0.3 % and 7.2 ± 0.8 % in the groups receiving conventional or high protein-BCAA diets, respectively. Fat mass was unchanged in both groups. At the end of BR, percent changes of insulin-mediated glucose uptake significantly (p = 0.01) decreased in the conventional diet group from 155 ± 23 % to 84 ± 10 % while did not change significantly in the high protein-BCAA diet group from 126 ± 20 % to 141 ± 27 % (BR effect, p = 0.32; BR/diet interaction, p = 0.01; Repeated Measures ANCOVA). In contrast, there were no BR/diet interactions on proteolysis and protein synthesis Clamp + AA changes in the conventional diet and the high protein-BCAA diet groups. CONCLUSION A high protein-BCAA enriched diet prevented inactivity-induced insulin resistance in healthy women.
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Affiliation(s)
- Alessandro Mangogna
- Institute for Maternal and Child Health, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Burlo Garofolo, Trieste, Italy
| | - Filippo Giorgio Di Girolamo
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy; Hospital Pharmacy, Cattinara Hospital, Azienda Sanitaria Universitaria Giuliano Isontina, Trieste, Italy
| | - Nicola Fiotti
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy
| | - Pierandrea Vinci
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy
| | - Matteo Landolfo
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy
| | - Filippo Mearelli
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy
| | - Gianni Biolo
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy.
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Yao H, Li K, Wei J, Lin Y, Liu Y. The contradictory role of branched-chain amino acids in lifespan and insulin resistance. Front Nutr 2023; 10:1189982. [PMID: 37408986 PMCID: PMC10318341 DOI: 10.3389/fnut.2023.1189982] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 05/26/2023] [Indexed: 07/07/2023] Open
Abstract
Branched-chain amino acids (BCAAs; a mixture of leucine, valine and isoleucine) have important regulatory effects on glucose and lipid metabolism, protein synthesis and longevity. Many studies have reported that circulating BCAA levels or dietary intake of BCAAs is associated with longevity, sarcopenia, obesity, and diabetes. Among them, the influence of BCAAs on aging and insulin resistance often present different benefits or harmful effects in the elderly and in animals. Considering the nonobvious correlation between circulating BCAA levels and BCAA uptake, as well as the influence of diseases, diet and aging on the body, some of the contradictory conclusions have been drawn. The regulatory mechanism of the remaining contradictory role may be related to endogenous branched-chain amino acid levels, branched-chain amino acid metabolism and mTOR-related autophagy. Furthermore, the recent discovery that insulin resistance may be independent of longevity has expanded the research thinking related to the regulatory mechanism among the three. However, the negative effects of BCAAs on longevity and insulin resistance were mostly observed in high-fat diet-fed subjects or obese individuals, while the effects in other diseases still need to be studied further. In conclusion, there is still no definite conclusion on the specific conditions under which BCAAs and insulin resistance extend life, shorten life, or do not change lifespan, and there is still no credible and comprehensive explanation for the different effects of BCAAs and insulin resistance on lifespan.
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Affiliation(s)
- He Yao
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Beijing Hospital, National Center of Gerontology, National Health Commission, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Kai Li
- Department of General Surgery, The First People’s Hospital of Taian, Taian, Shandong, China
| | - Jie Wei
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Beijing Hospital, National Center of Gerontology, National Health Commission, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Yajun Lin
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Beijing Hospital, National Center of Gerontology, National Health Commission, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Yinghua Liu
- Department of Nutrition, National Clinical Research Center for Geriatric Diseases, The First Medical Center of Chinese PLA General Hospital, Beijing, China
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Surugihalli C, Muralidaran V, Ryan CE, Patel K, Zhao D, Sunny NE. Branched-chain amino acids alter cellular redox to induce lipid oxidation and reduce de novo lipogenesis in the liver. Am J Physiol Endocrinol Metab 2023; 324:E299-E313. [PMID: 36791321 PMCID: PMC10042599 DOI: 10.1152/ajpendo.00307.2022] [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: 11/17/2022] [Revised: 01/30/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023]
Abstract
Metabolic and molecular interactions between branched-chain amino acid (BCAA) and lipid metabolism are evident in insulin-resistant tissues. However, it remains unclear whether insulin resistance is a prerequisite for these relationships and whether BCAAs or their metabolic intermediates can modulate hepatic lipid oxidation and synthesis. We hypothesized that BCAAs can alter hepatic oxidative function and de novo lipogenesis, independent of them being anaplerotic substrates for the mitochondria. Mice (C57BL/6NJ) were reared on a low-fat (LF), LF diet plus 1.5X BCAAs (LB), high-fat (HF) or HF diet plus 1.5X BCAAs (HB) for 12 wk. Hepatic metabolism was profiled utilizing stable isotopes coupled to mass spectrometry and nuclear magnetic resonance, together with fed-to-fasted changes in gene and protein expression. A greater induction of lipid oxidation and ketogenesis on fasting was evident in the BCAA-supplemented, insulin-sensitive livers from LB mice, whereas their rates of hepatic de novo lipogenesis remained lower than their LF counterparts. Onset of insulin resistance in HF and HB mice livers blunted these responses. Whole body turnover of BCAAs and their ketoacids, their serum concentrations, and the ketogenic flux from BCAA catabolism, all remained similar between fasted LF and LB mice. This suggested that the impact of BCAAs on lipid metabolism can occur independent of them or their degradation products fueling anaplerosis through the liver mitochondria. Furthermore, the greater induction of lipid oxidation in the LB livers accompanied higher mitochondrial NADH/NAD+ ratio and higher fed-to-fasting phosphorylation of AMPKα and ACC. Taken together, our results provide evidence that BCAA supplementation, under conditions of insulin sensitivity, improved the feeding-to-fasting induction of hepatic lipid oxidation through changes in cellular redox, thus providing a favorable biochemical environment for flux through β-oxidation and lower de novo lipogenesis.NEW & NOTEWORTHY Branched-chain amino acids (BCAAs) have been shown to modulate lipid metabolic networks in various tissues, especially during insulin resistance. In this study we show that the dietary supplementation of BCAAs to normal, insulin-sensitive mice resulted in higher mitochondrial NADH:NAD+ ratios and AMPK activation in the liver. This change in the cellular redox status provided an optimal metabolic milieu to increase fatty acid oxidation while keeping the rates of de novo lipogenesis lower in the BCAA-supplemented mice livers.
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Affiliation(s)
- Chaitra Surugihalli
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, United States
| | - Vaishna Muralidaran
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, United States
| | - Caitlin E Ryan
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, United States
| | - Kruti Patel
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, United States
| | - David Zhao
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, United States
| | - Nishanth E Sunny
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, United States
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Gumus Balikcioglu P, Jachthuber Trub C, Balikcioglu M, Ilkayeva O, White PJ, Muehlbauer M, Bain JR, Armstrong S, Freemark M. Branched-chain α-keto acids and glutamate/glutamine: Biomarkers of insulin resistance in childhood obesity. Endocrinol Diabetes Metab 2023; 6:e388. [PMID: 36415168 PMCID: PMC9836245 DOI: 10.1002/edm2.388] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/09/2022] [Accepted: 10/16/2022] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES Insulin resistance (IR) in adolescents with obesity is associated with a sex-dependent metabolic 'signature' comprising the branched-chain amino acids (BCAAs), glutamate/glutamine, C3/C5 acylcarnitines and uric acid. Here, we compared the levels of branched-chain α-keto acids (BCKAs) and glutamate/glutamine, which are the byproducts of BCAA catabolism and uric acid among adolescents with obesity prior to and following a 6-month lifestyle-intervention program. METHODS Fasting plasma samples from 33 adolescents with obesity (16 males, 17 females, aged 12-18 year) were analysed by flow-injection tandem MS and LC-MS/MS. Multiple linear regression models were used to correlate changes in BCKAs, glutamate/glutamine and uric acid with changes in weight and insulin sensitivity as assessed by HOMA-IR, adiponectin and the ratio of triglyceride (TG) to HDL. In predictive models, BCKAs, glutamate/glutamine and uric acid at baseline were used as explanatory variables. RESULTS Baseline BCKAs, glutamate/glutamine and uric acid were higher in males than females despite comparable BMI-metrics. Following lifestyle-intervention, α-keto-β-methylvalerate (α-KMV, a metabolic by product of isoleucine) decreased in males but not in females. The ratio of BCKA/BCAA trended lower in males. In the cohort as a whole, BCKAs correlated positively with the ratio of TG to HDL at baseline and HOMA-IR at 6-month-follow-up. Glutamate/glutamine was positively associated with HOMA-IR at baseline and 6-month-follow-up. A reduction in BCKAs was associated with an increase in adiponectin, and those with higher BCKAs at baseline had higher adiponectin levels at 6-month-follow-up. Interestingly those adolescents with higher uric acid levels at baseline had greater reduction in weight. CONCLUSIONS BCKAs and glutamate/glutamine may serve as biomarkers of IR in adolescents with obesity, and uric acid might serve as a predictor of weight loss in response to lifestyle-intervention. Differential regulation of BCAA catabolism in adolescent males and females implicates critical roles for sex steroids in metabolic homeostasis.
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Affiliation(s)
- Pinar Gumus Balikcioglu
- Division of Pediatric Endocrinology and Diabetes, Duke University Medical Center, Durham, North Carolina, USA.,Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, USA
| | | | - Metin Balikcioglu
- Advanced Analytics Division, SAS Institute Inc, Cary, North Carolina, USA
| | - Olga Ilkayeva
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, USA.,Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Durham, North Carolina, USA
| | - Phillip J White
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, USA.,Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Durham, North Carolina, USA
| | - Michael Muehlbauer
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, USA
| | - James R Bain
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, USA.,Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Durham, North Carolina, USA
| | - Sarah Armstrong
- Division of General Pediatrics and Adolescent Health, Duke University Medical Center, Durham, North Carolina, USA.,Department of Family Medicine and Community Health, Duke University Medical Center, Durham, North Carolina, USA.,Department of Population Health Sciences, Duke University Medical Center, Durham, North Carolina, USA.,Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina, USA
| | - Michael Freemark
- Division of Pediatric Endocrinology and Diabetes, Duke University Medical Center, Durham, North Carolina, USA.,Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, USA
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10
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Branched-Chain Amino Acids and Insulin Resistance, from Protein Supply to Diet-Induced Obesity. Nutrients 2022; 15:nu15010068. [PMID: 36615726 PMCID: PMC9824001 DOI: 10.3390/nu15010068] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/30/2022] [Accepted: 12/09/2022] [Indexed: 12/28/2022] Open
Abstract
For more than a decade, there has been a wide debate about the branched-chain amino acids (BCAA) leucine, valine, and isoleucine, with, on the one hand, the supporters of their anabolic effects and, on the other hand, those who suspect them of promoting insulin resistance. Indeed, the role of leucine in the postprandial activation of protein synthesis has been clearly established, even though supplementation studies aimed at taking advantage of this property are rather disappointing. Furthermore, there is ample evidence of an association between the elevation of their plasma concentrations and insulin resistance or the risk of developing type 2 diabetes, although there are many confounding factors, starting with the level of animal protein consumption. After a summary of their metabolism and anabolic properties, we analyze in this review the factors likely to increase the plasma concentrations of BCAAs, including insulin-resistance. After an analysis of supplementation or restriction studies in search of a direct role of BCAAs in insulin resistance, we discuss an indirect role through some of their metabolites: branched-chain keto acids, C3 and C5 acylcarnitines, and hydroxyisobutyrate. Overall, given the importance of insulin in the metabolism of these amino acids, it is very likely that small alterations in insulin sensitivity are responsible for a reduction in their catabolism long before the onset of impaired glucose tolerance.
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11
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Caloric restriction improves glycaemic control without reducing plasma branched-chain amino acids or keto-acids in obese men. Sci Rep 2022; 12:19273. [PMID: 36369511 PMCID: PMC9652417 DOI: 10.1038/s41598-022-21814-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 10/04/2022] [Indexed: 11/13/2022] Open
Abstract
Higher plasma leucine, isoleucine and valine (BCAA) concentrations are associated with diabetes, obesity and insulin resistance (IR). Here, we evaluated the effects of 6-weeks very-low calorie diet (VLCD) upon fasting BCAA in overweight (OW) non-diabetic men, to explore associations between circulating BCAA and IR, before and after a weight loss intervention. Fasting plasma BCAAs were quantified in an OW (n = 26; BMI 32.4 ± 3 kg/m2; mean age 44 ± 9 y) and a normal-weight (NW) group (n = 26; BMI 24 ± 3.1 kg/m2; mean age 32 ± 12.3 y). Ten of the OW group (BMI 32.2 ± 4 kg/m2; 46 ± 8 y) then underwent 6-weeks of VLCD (600-800 kcal/day). Fasting plasma BCAA (gas chromatography-mass spectrometry), insulin sensitivity (HOMA-IR) and body-composition (DXA) were assessed before and after VLCD. Total BCAA were higher in OW individuals (sum leucine/isoleucine/valine: 457 ± 85 µM) compared to NW control individuals (365 ± 78 µM, p < 0.001). Despite significant weight loss (baseline 103.9 ± 12.3 to 93 ± 9.6 kg and BMI 32.2 ± 4 to 28.9 ± 3.6 kg/m2), no changes were observed in BCAAs after 6-weeks of VLCD. Moreover, although VLCD resulted in a significant reduction in HOMA-IR (baseline 1.19 ± 0.62 to 0.51 ± 0.21 post-VLCD; p < 0.001), Pearson's r revealed no relationships between BCAA and HOMA-IR, either before (leucine R2: 2.49e-005, p = 0.98; isoleucine R2: 1.211-e006, p = 0.9; valine R2: 0.004, p = 0.85) or after VLCD (leucine R2: 0.003, p = 0.86; isoleucine R2: 0.006, p = 0.82; valine R2: 0.002, p = 0.65). Plasma BCAA are higher in OW compared to NW individuals. However, while 6-weeks VLCD reduced body weight and IR in OW individuals, this was not associated with reductions in BCAA. This suggests that studies demonstrating links between BCAA and insulin resistance in OW individuals, are complex and are not normalised by simply losing weight.
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12
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Cai Z, Li W, Brenner M, Bahiraii S, Heiss EH, Weckwerth W. Branched-chain ketoacids derived from cancer cells modulate macrophage polarization and metabolic reprogramming. Front Immunol 2022; 13:966158. [PMID: 36311795 PMCID: PMC9606345 DOI: 10.3389/fimmu.2022.966158] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/12/2022] [Indexed: 11/18/2022] Open
Abstract
Macrophages are prominent immune cells in the tumor microenvironment that can be educated into pro-tumoral phenotype by tumor cells to favor tumor growth and metastasis. The mechanisms that mediate a mutualistic relationship between tumor cells and macrophages remain poorly characterized. Here, we have shown in vitro that different human and murine cancer cell lines release branched-chain α-ketoacids (BCKAs) into the extracellular milieu, which influence macrophage polarization in an monocarboxylate transporter 1 (MCT1)-dependent manner. We found that α-ketoisocaproate (KIC) and α-keto-β-methylvalerate (KMV) induced a pro-tumoral macrophage state, whereas α-ketoisovalerate (KIV) exerted a pro-inflammatory effect on macrophages. This process was further investigated by a combined metabolomics/proteomics platform. Uptake of KMV and KIC fueled macrophage tricarboxylic acid (TCA) cycle intermediates and increased polyamine metabolism. Proteomic and pathway analyses revealed that the three BCKAs, especially KMV, exhibited divergent effects on the inflammatory signal pathways, phagocytosis, apoptosis and redox balance. These findings uncover cancer-derived BCKAs as novel determinants for macrophage polarization with potential to be selectively exploited for optimizing antitumor immune responses.
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Affiliation(s)
- Zhengnan Cai
- Molecular Systems Biology (MOSYS), Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Wan Li
- Molecular Systems Biology (MOSYS), Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Martin Brenner
- Molecular Systems Biology (MOSYS), Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Sheyda Bahiraii
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Elke H. Heiss
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Wolfram Weckwerth
- Molecular Systems Biology (MOSYS), Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
- Vienna Metabolomics Center (VIME), University of Vienna, Vienna, Austria
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13
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Bollinger E, Peloquin M, Libera J, Albuquerque B, Pashos E, Shipstone A, Hadjipanayis A, Sun Z, Xing G, Clasquin M, Stansfield JC, Tierney B, Gernhardt S, Siddall CP, Greizer T, Geoly FJ, Vargas SR, Gao LC, Williams G, Marshall M, Rosado A, Steppan C, Filipski KJ, Zhang BB, Miller RA, Roth Flach RJ. BDK inhibition acts as a catabolic switch to mimic fasting and improve metabolism in mice. Mol Metab 2022; 66:101611. [PMID: 36220546 PMCID: PMC9589198 DOI: 10.1016/j.molmet.2022.101611] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/05/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE Branched chain amino acid (BCAA) catabolic defects are implicated to be causal determinates of multiple diseases. This work aimed to better understand how enhancing BCAA catabolism affected metabolic homeostasis as well as the mechanisms underlying these improvements. METHODS The rate limiting step of BCAA catabolism is the irreversible decarboxylation by the branched chain ketoacid dehydrogenase (BCKDH) enzyme complex, which is post-translationally controlled through phosphorylation by BCKDH kinase (BDK). This study utilized BT2, a small molecule allosteric inhibitor of BDK, in multiple mouse models of metabolic dysfunction and NAFLD including the high fat diet (HFD) model with acute and chronic treatment paradigms, the choline deficient and methionine minimal high fat diet (CDAHFD) model, and the low-density lipoprotein receptor null mouse model (Ldlr-/-). shRNA was additionally used to knock down BDK in liver to elucidate liver-specific effects of BDK inhibition in HFD-fed mice. RESULTS A rapid improvement in insulin sensitivity was observed in HFD-fed and lean mice after BT2 treatment. Resistance to steatosis was assessed in HFD-fed mice, CDAHFD-fed mice, and Ldlr-/- mice. In all cases, BT2 treatment reduced steatosis and/or inflammation. Fasting and refeeding demonstrated a lack of response to feeding-induced changes in plasma metabolites including insulin and beta-hydroxybutyrate and hepatic gene changes in BT2-treated mice. Mechanistically, BT2 treatment acutely altered the expression of genes involved in fatty acid oxidation and lipogenesis in liver, and upstream regulator analysis suggested that BT2 treatment activated PPARα. However, BT2 did not directly activate PPARα in vitro. Conversely, shRNA-AAV-mediated knockdown of BDK specifically in liver in vivo did not demonstrate any effects on glycemia, steatosis, or PPARα-mediated gene expression in mice. CONCLUSIONS These data suggest that BT2 treatment acutely improves metabolism and liver steatosis in multiple mouse models. While many molecular changes occur in liver in BT2-treated mice, these changes were not observed in mice with AAV-mediated shRNA knockdown of BDK. All together, these data suggest that systemic BDK inhibition is required to improve metabolism and steatosis by prolonging a fasting signature in a paracrine manner. Therefore, BCAA may act as a "fed signal" to promote nutrient storage and reduced systemic BCAA levels as shown in this study via BDK inhibition may act as a "fasting signal" to prolong the catabolic state.
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Affiliation(s)
- Eliza Bollinger
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Matthew Peloquin
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Jenna Libera
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Bina Albuquerque
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Evanthia Pashos
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Arun Shipstone
- Inflammation & Immunology Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Angela Hadjipanayis
- Inflammation & Immunology Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Zhongyuan Sun
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Gang Xing
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Michelle Clasquin
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | | | | | | | - C. Parker Siddall
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Timothy Greizer
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Frank J. Geoly
- Drug Safety Research and Development, Pfizer Inc, Groton CT 06340, USA
| | - Sarah R. Vargas
- Drug Safety Research and Development, Pfizer Inc, Groton CT 06340, USA
| | - Lily C. Gao
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - George Williams
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | | | - Amy Rosado
- Medicine Design, Pfizer Inc, Groton, CT 06340, USA
| | | | | | - Bei B. Zhang
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Russell A. Miller
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA
| | - Rachel J. Roth Flach
- Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA,Corresponding author. Pfizer Inc, 1 Portland St, Cambridge MA 02139, USA.
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14
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Gong Q, Zhang R, Wei F, Fang J, Zhang J, Sun J, Sun Q, Wang H. SGLT2 inhibitor-empagliflozin treatment ameliorates diabetic retinopathy manifestations and exerts protective effects associated with augmenting branched chain amino acids catabolism and transportation in db/db mice. Biomed Pharmacother 2022; 152:113222. [PMID: 35671581 DOI: 10.1016/j.biopha.2022.113222] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/26/2022] [Accepted: 05/30/2022] [Indexed: 11/28/2022] Open
Abstract
Empagliflozin (EMPA) is the first sodium-glucose co-transporter 2 inhibitor to significantly reduce cardiovascular and kidney complications in type 2 diabetes mellitus. Given this, we speculate that EMPA may have the potential to intervene in diabetic retinopathy (DR), which is another diabetes-specific microvascular complication. Db/db mice were treated with EMPA for different periods to observe the retinas and related mechanisms. EMPA effectively balanced body weight and blood glucose levels, mitigated ocular edema and microaneurysm in db/db mice. EMPA significantly inhibited oxidative stress, apoptosis and recovered tight junction in diabetic retinas. MS/MS analyses showed that EMPA suppressed aberrant branched-chain amino acid (BCAAs) accumulation in db/db retinas, which led to the inhibition of the mammalian target of rapamycin activation, downregulation of inflammation, and angiogenic factors, including TNF-ɑ, IL-6, VCAM-1, and VEGF induced by diabetes. Furthermore, branched-chain α-keto acids (BCKAs), which are catabolites of BCAAs, were increased in diabetic retinas and decreased with EMPA application. Moreover, branched-chain ketoacid dehydrogenase kinase (BCKDK) was enhanced, BCKDHA and BCKDHB were decreased in diabetic retinas. This could be reversed by EMPA treatment, thus promoting BCAAs catabolism to decrease BCAAs and BCKAs accumulation in diabetic retinas. The high levels of BCAAs in the plasma and enhanced L-type amino acid transporter 1 (LAT1) were responsible for the high levels of BCAAs in diabetic retinas, which could be inhibited by EMPA. Overall, EMPA could ameliorate DR manifestations. The normalization of BCAAs catabolism and intake may play a role in this process. This study supports EMPA as a protective drug against DR.
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Affiliation(s)
- Qiaoyun Gong
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Rulin Zhang
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Fang Wei
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Junwei Fang
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Jingfa Zhang
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Jun Sun
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Qian Sun
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Haiyan Wang
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.
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15
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Du C, Liu WJ, Yang J, Zhao SS, Liu HX. The Role of Branched-Chain Amino Acids and Branched-Chain α-Keto Acid Dehydrogenase Kinase in Metabolic Disorders. Front Nutr 2022; 9:932670. [PMID: 35923208 PMCID: PMC9339795 DOI: 10.3389/fnut.2022.932670] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 06/16/2022] [Indexed: 12/16/2022] Open
Abstract
Branched-chain amino acids (BCAAs), composed of leucine, isoleucine, and valine, are important essential amino acids in human physiology. Decades of studies have revealed their roles in protein synthesis, regulating neurotransmitter synthesis, and the mechanistic target of rapamycin (mTOR). BCAAs are found to be related to many metabolic disorders, such as insulin resistance, obesity, and heart failure. Also, many diseases are related to the alteration of the BCAA catabolism enzyme branched-chain α-keto acid dehydrogenase kinase (BCKDK), including maple syrup urine disease, human autism with epilepsy, and so on. In this review, diseases and the corresponding therapies are discussed after the introduction of the catabolism and detection methods of BCAAs and BCKDK. Also, the interaction between microbiota and BCAAs is highlighted.
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Affiliation(s)
- Chuang Du
- Institute of Life Sciences, China Medical University, Shenyang, China
- Health Sciences Institute, China Medical University, Shenyang, China
- Liaoning Key Laboratory of Obesity and Glucose/Lipid Associated Metabolic Diseases, China Medical University, Shenyang, China
- Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Wen-Jie Liu
- Institute of Life Sciences, China Medical University, Shenyang, China
- Health Sciences Institute, China Medical University, Shenyang, China
- Liaoning Key Laboratory of Obesity and Glucose/Lipid Associated Metabolic Diseases, China Medical University, Shenyang, China
| | - Jing Yang
- Institute of Life Sciences, China Medical University, Shenyang, China
- Health Sciences Institute, China Medical University, Shenyang, China
- Liaoning Key Laboratory of Obesity and Glucose/Lipid Associated Metabolic Diseases, China Medical University, Shenyang, China
| | - Shan-Shan Zhao
- Institute of Life Sciences, China Medical University, Shenyang, China
- Health Sciences Institute, China Medical University, Shenyang, China
- Liaoning Key Laboratory of Obesity and Glucose/Lipid Associated Metabolic Diseases, China Medical University, Shenyang, China
- Department of Gynecology, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Shenyang, China
- *Correspondence: Shan-Shan Zhao,
| | - Hui-Xin Liu
- Institute of Life Sciences, China Medical University, Shenyang, China
- Health Sciences Institute, China Medical University, Shenyang, China
- Liaoning Key Laboratory of Obesity and Glucose/Lipid Associated Metabolic Diseases, China Medical University, Shenyang, China
- Hui-Xin Liu,
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16
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Effect of the BCAT2 polymorphism (rs11548193) on plasma branched-chain amino acid concentrations after dietary intervention in subjects with obesity and insulin resistance. Br J Nutr 2022; 128:43-54. [PMID: 34340727 DOI: 10.1017/s0007114521002920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Branched-chain amino acids (BCAA) are considered markers of insulin resistance (IR) in subjects with obesity. In this study, we evaluated whether the presence of the SNP of the branched-chain aminotransferase 2 (BCAT2) gene can modify the effect of a dietary intervention (DI) on the plasma concentration of BCAA in subjects with obesity and IR. A prospective cohort study of adult subjects with obesity, BMI ≥ 30 kg/m2, homeostatic model assessment-insulin resistance (HOMA-IR ≥ 2·5) no diagnosed chronic disease, underwent a DI with an energy restriction of 3140 kJ/d and nutritional education for 1 month. Anthropometric measurements, body composition, blood pressure, resting energy expenditure, oral glucose tolerance test results, serum biochemical parameters and the plasma amino acid profile were evaluated before and after the DI. SNP were assessed by the TaqMan SNP genotyping assay. A total of eighty-two subjects were included, and fifteen subjects with a BCAT2 SNP had a greater reduction in leucine, isoleucine, valine and the sum of BCAA. Those subjects also had a greater reduction in skeletal muscle mass, fat-free mass, total body water, blood pressure, muscle strength and biochemical parameters after 1 month of the DI and adjusting for age and sex. This study demonstrated that the presence of the BCAT2 SNP promotes a greater reduction in plasma BCAA concentration after adjusting for age and sex, in subjects with obesity and IR after a 1-month energy-restricted DI.
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17
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Yahsi B, Gunaydin G. Immunometabolism – The Role of Branched-Chain Amino Acids. Front Immunol 2022; 13:886822. [PMID: 35812393 PMCID: PMC9259854 DOI: 10.3389/fimmu.2022.886822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 05/16/2022] [Indexed: 12/12/2022] Open
Abstract
Immunometabolism has been the focus of extensive research over the last years, especially in terms of augmenting anti-tumor immune responses. Regulatory T cells (Tregs) are a subset of CD4+ T cells, which have been known for their immunosuppressive roles in various conditions including anti-tumor immune responses. Even though several studies aimed to target Tregs in the tumor microenvironment (TME), such approaches generally result in the inhibition of the Tregs non-specifically, which may cause immunopathologies such as autoimmunity. Therefore, specifically targeting the Tregs in the TME would be vital in terms of achieving a successful and specific treatment. Recently, an association between Tregs and isoleucine, which represents one type of branched-chain amino acids (BCAAs), has been demonstrated. The presence of isoleucine seems to affect majorly Tregs, rather than conventional T cells. Considering the fact that Tregs bear several distinct metabolic features in the TME, targeting their immunometabolic pathways may be a rational approach. In this Review, we provide a general overview on the potential distinct metabolic features of T cells, especially focusing on BCAAs in Tregs as well as in their subtypes.
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Affiliation(s)
- Berkay Yahsi
- School of Medicine, Hacettepe University, Ankara, Turkey
| | - Gurcan Gunaydin
- Department of Basic Oncology, Cancer Institute, Hacettepe University, Ankara, Turkey
- *Correspondence: Gurcan Gunaydin,
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18
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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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19
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Uddin GM, Karwi QG, Pherwani S, Gopal K, Wagg CS, Biswas D, Atnasious M, Wu Y, Wu G, Zhang L, Ho KL, Pulinilkunnil T, Ussher JR, Lopaschuk GD. Deletion of BCATm increases insulin-stimulated glucose oxidation in the heart. Metabolism 2021; 124:154871. [PMID: 34478752 DOI: 10.1016/j.metabol.2021.154871] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 08/21/2021] [Accepted: 08/27/2021] [Indexed: 02/01/2023]
Abstract
BACKGROUNDS Branched chain amino acid (BCAA) oxidation is impaired in cardiac insulin resistance, leading to the accumulation of BCAAs and the first products of BCAA oxidation, the branched chain ketoacids. However, it is not clear whether it is the BCAAs, BCKAs or both that are mediating cardiac insulin resistance. To determine this, we produced mice with a cardiac-specific deletion of BCAA aminotransferase (BCATm-/-), the first enzyme in the BCAA oxidation pathway that is responsible for converting BCAAs to BCKAs. METHODS Eight-week-old BCATm cardiac specific knockout (BCATm-/-) male mice and their α-MHC (myosin heavy chain) - Cre expressing wild type littermates (WT-Cre+/+) received tamoxifen (50 mg/kg i.p. 6 times over 8 days). At 16-weeks of age, cardiac energy metabolism was assessed in isolated working hearts. RESULTS BCATm-/- mice have decreased cardiac BCAA oxidation rates, increased cardiac BCAAs and a reduction in cardiac BCKAs. Hearts from BCATm-/- mice showed an increase in insulin stimulation of glucose oxidation and an increase in p-AKT. To determine the impact of reversing these events, we perfused isolated working mice hearts with high levels of BCKAs, which completely abolished insulin-stimulated glucose oxidation rates, an effect associated with decreased p-AKT and inactivation of pyruvate dehydrogenase (PDH), the rate-limiting enzyme in glucose oxidation. CONCLUSION This implicates the BCKAs, and not BCAAs, as the actual mediators of cardiac insulin resistance and suggests that lowering cardiac BCKAs can be used as a therapeutic strategy to improve insulin sensitivity in the heart.
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Affiliation(s)
- Golam M Uddin
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Qutuba G Karwi
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada; Department of Pharmacology, College of Medicine, University of Diyala, Diyala, Iraq
| | - Simran Pherwani
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Keshav Gopal
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, Canada; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
| | - Cory S Wagg
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Dipsikha Biswas
- Department of Biochemistry Molecular Biology, Dalhousie University, Canada
| | - Mariam Atnasious
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Yikuan Wu
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Guoqing Wu
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada; State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China
| | - Liyan Zhang
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Kim L Ho
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | | | - John R Ussher
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, Canada; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
| | - Gary D Lopaschuk
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada; Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, Canada.
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Supruniuk E, Żebrowska E, Chabowski A. Branched chain amino acids-friend or foe in the control of energy substrate turnover and insulin sensitivity? Crit Rev Food Sci Nutr 2021; 63:2559-2597. [PMID: 34542351 DOI: 10.1080/10408398.2021.1977910] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Branched chain amino acids (BCAA) and their derivatives are bioactive molecules with pleiotropic functions in the human body. Elevated fasting blood BCAA concentrations are considered as a metabolic hallmark of obesity, insulin resistance, dyslipidaemia, nonalcoholic fatty liver disease, type 2 diabetes and cardiovascular disease. However, since increased BCAA amount is observed both in metabolically healthy and obese subjects, a question whether BCAA are mechanistic drivers of insulin resistance and its morbidities or only markers of metabolic dysregulation, still remains open. The beneficial effects of BCAA on body weight and composition, aerobic capacity, insulin secretion and sensitivity demand high catabolic potential toward amino acids and/or adequate BCAA intake. On the opposite, BCAA-related inhibition of lipogenesis and lipolysis enhancement may preclude impairment in insulin sensitivity. Thereby, the following review addresses various strategies pertaining to the modulation of BCAA catabolism and the possible roles of BCAA in energy homeostasis. We also aim to elucidate mechanisms behind the heterogeneity of ramifications associated with BCAA modulation.
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Affiliation(s)
- Elżbieta Supruniuk
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Ewa Żebrowska
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
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21
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Inhibiting BCKDK in triple negative breast cancer suppresses protein translation, impairs mitochondrial function, and potentiates doxorubicin cytotoxicity. Cell Death Discov 2021; 7:241. [PMID: 34526485 PMCID: PMC8443725 DOI: 10.1038/s41420-021-00602-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/25/2021] [Accepted: 07/26/2021] [Indexed: 02/06/2023] Open
Abstract
Triple-negative breast cancers (TNBCs) are characterized by poor survival, prognosis, and gradual resistance to cytotoxic chemotherapeutics, like doxorubicin (DOX). The clinical utility of DOX is limited by its cardiotoxic and chemoresistant effects that manifest over time. To induce chemoresistance, TNBC rewires oncogenic gene expression and cell signaling pathways. Recent studies have demonstrated that reprogramming of branched-chain amino acids (BCAAs) metabolism facilitates tumor growth and survival. Branched-chain ketoacid dehydrogenase kinase (BCKDK), a regulatory kinase of the rate-limiting enzyme of the BCAA catabolic pathway, is reported to activate RAS/RAF/MEK/ERK signaling to promote tumor cell proliferation. However, it remains unexplored if BCKDK action remodels TNBC proliferation and survival per se and influences susceptibility to DOX-induced genotoxic stress. TNBC cells treated with DOX exhibited reduced BCKDK expression and intracellular BCKAs. Genetic and pharmacological inhibition of BCKDK in TNBC cell lines also showed a similar reduction in intracellular and secreted BCKAs. BCKDK silencing in TNBC cells downregulated mitochondrial metabolism genes, reduced electron complex protein expression, oxygen consumption, and ATP production. Transcriptome analysis of BCKDK silenced cells confirmed dysregulation of mitochondrial metabolic networks and upregulation of the apoptotic signaling pathway. Furthermore, BCKDK inhibition with concurrent DOX treatment exacerbated apoptosis, caspase activity, and loss of TNBC proliferation. Inhibition of BCKDK in TNBC also upregulated sestrin 2 and concurrently decreased mTORC1 signaling and protein synthesis. Overall, loss of BCKDK action in TNBC remodels BCAA flux, reduces protein translation triggering cell death, ATP insufficiency, and susceptibility to genotoxic stress. Proposed mechanism. A Doxorubicin (DOX) targets the BCAA catabolic pathway in TNBCs, by downregulating BCKDK and augmenting clearance of intracellular BCKAs. B Genetic or pharmacological (high BT2 concentration) inhibition of BCKDK results in increased cell death, decreased intracellular BCKAs, dysregulated mitochondrial function, ATP insufficiency, SESN2 activation, and inhibition of mTORC1 signaling and protein synthesis. C BCKDK inhibition (siRNA mediated or low-BT2 concentration) exacerbates DOX-induced cytotoxicity and caspase activity. ![]()
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White JP. Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand. Front Cell Dev Biol 2021; 9:656604. [PMID: 34136478 PMCID: PMC8201612 DOI: 10.3389/fcell.2021.656604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 04/28/2021] [Indexed: 11/20/2022] Open
Abstract
Skeletal muscle protein synthesis is a highly complex process, influenced by nutritional status, mechanical stimuli, repair programs, hormones, and growth factors. The molecular aspects of protein synthesis are centered around the mTORC1 complex. However, the intricacies of mTORC1 regulation, both up and downstream, have expanded overtime. Moreover, the plastic nature of skeletal muscle makes it a unique tissue, having to coordinate between temporal changes in myofiber metabolism and hypertrophy/atrophy stimuli within a tissue with considerable protein content. Skeletal muscle manages the push and pull between anabolic and catabolic pathways through key regulatory proteins to promote energy production in times of nutrient deprivation or activate anabolic pathways in times of nutrient availability and anabolic stimuli. Branched-chain amino acids (BCAAs) can be used for both energy production and signaling to induce protein synthesis. The metabolism of BCAAs occur in tandem with energetic and anabolic processes, converging at several points along their respective pathways. The fate of intramuscular BCAAs adds another layer of regulation, which has consequences to promote or inhibit muscle fiber protein anabolism. This review will outline the general mechanisms of muscle protein synthesis and describe how metabolic pathways can regulate this process. Lastly, we will discuss how BCAA availability and demand coordinate with synthesis mechanisms and identify key factors involved in intramuscular BCAA trafficking.
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Affiliation(s)
- James P White
- Department of Medicine, Duke University School of Medicine, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, United States.,Duke Center for the Study of Aging and Human Development, Duke University School of Medicine, Durham, NC, United States
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Whole-body metabolic fate of branched-chain amino acids. Biochem J 2021; 478:765-776. [PMID: 33626142 DOI: 10.1042/bcj20200686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/01/2021] [Accepted: 02/03/2021] [Indexed: 12/12/2022]
Abstract
Oxidation of branched-chain amino acids (BCAAs) is tightly regulated in mammals. We review here the distribution and regulation of whole-body BCAA oxidation. Phosphorylation and dephosphorylation of the rate-limiting enzyme, branched-chain α-ketoacid dehydrogenase complex directly regulates BCAA oxidation, and various other indirect mechanisms of regulation also exist. Most tissues throughout the body are capable of BCAA oxidation, and the flux of oxidative BCAA disposal in each tissue is influenced by three key factors: 1. tissue-specific preference for BCAA oxidation relative to other fuels, 2. the overall oxidative activity of mitochondria within a tissue, and 3. total tissue mass. Perturbations in BCAA oxidation have been implicated in many disease contexts, underscoring the importance of BCAA homeostasis in overall health.
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Biswas D, Pulinilkunnil T. Disrupted branched-chain amino acid catabolism impair cardiac insulin signaling and is associated with adverse cardiometabolic outcomes. J Mol Cell Cardiol 2020; 153:93-94. [PMID: 33378687 DOI: 10.1016/j.yjmcc.2020.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/26/2020] [Accepted: 12/18/2020] [Indexed: 10/22/2022]
Affiliation(s)
- Dipsikha Biswas
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada.
| | - Thomas Pulinilkunnil
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
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