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Pan Y, Hatano A, Ohno S, Morita K, Kokaji T, Bai Y, Sugimoto H, Egami R, Terakawa A, Li D, Uematsu S, Maehara H, Fujita S, Inoue H, Inaba Y, Nagano AJ, Hirayama A, Soga T, Kuroda S. Time and dose selective glucose metabolism for glucose homeostasis and energy conversion in the liver. NPJ Syst Biol Appl 2024; 10:107. [PMID: 39349490 PMCID: PMC11443093 DOI: 10.1038/s41540-024-00437-2] [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: 04/20/2024] [Accepted: 09/10/2024] [Indexed: 10/02/2024] Open
Abstract
Hepatic glucose metabolism serves dual purposes: maintaining glucose homeostasis and converting glucose into energy sources; however, the underlying mechanisms are unclear. We quantitatively measured liver metabolites, gene expression, and phosphorylated insulin signaling molecules in mice orally administered varying doses of glucose, and constructed a transomic network. Rapid phosphorylation of insulin signaling molecules in response to glucose intake was observed, in contrast to the more gradual changes in gene expression. Glycolytic and gluconeogenic metabolites and expression of genes involved in glucose metabolism including glucose-6-phosphate, G6pc, and Pck1, demonstrated high glucose dose sensitivity. Whereas, glucokinase expression and glycogen accumulation showed low glucose dose sensitivity. During the early phase after glucose intake, metabolic flux was geared towards glucose homeostasis regardless of the glucose dose but shifted towards energy conversion during the late phase at higher glucose doses. Our research provides a comprehensive view of time- and dose-dependent selective glucose metabolism.
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Affiliation(s)
- Yifei Pan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Atsushi Hatano
- Department of Omics and Systems Biology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
- Laboratory for Integrated Cellular Systems, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Satoshi Ohno
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Department of AI Systems Medicine, M&D Data Science Center, Tokyo Medical and Dental University, Tokyo, Japan
- Molecular Genetics Research Laboratory, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Keigo Morita
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Molecular Genetics Research Laboratory, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Toshiya Kokaji
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Data Science Center, Nara Institute of Science and Technology, Ikoma, Japan
| | - Yunfan Bai
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Hikaru Sugimoto
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Riku Egami
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Akira Terakawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Dongzi Li
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Saori Uematsu
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Hideki Maehara
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Suguru Fujita
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Inoue
- Metabolism and Nutrition Research Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Yuka Inaba
- Metabolism and Nutrition Research Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Atsushi J Nagano
- Faculty of Agriculture, Ryukoku University, Otsu, Shiga, Japan
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
| | - Akiyoshi Hirayama
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
| | - Tomoyoshi Soga
- Human Biology-Microbiome-Quantum Research Center (WPI-Bio2Q), Keio University, 108-8345, Tokyo, Japan
| | - Shinya Kuroda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan.
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
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Bednarski TK, Rahim M, Hasenour CM, Banerjee DR, Trenary IA, Wasserman DH, Young JD. Pharmacological SERCA activation limits diet-induced steatohepatitis and restores liver metabolic function in mice. J Lipid Res 2024; 65:100558. [PMID: 38729350 PMCID: PMC11179628 DOI: 10.1016/j.jlr.2024.100558] [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: 01/25/2024] [Revised: 04/26/2024] [Accepted: 04/28/2024] [Indexed: 05/12/2024] Open
Abstract
Metabolic dysfunction-associated steatotic liver disease is the most common form of liver disease and poses significant health risks to patients who progress to metabolic dysfunction-associated steatohepatitis. Fatty acid overload alters endoplasmic reticulum (ER) calcium stores and induces mitochondrial oxidative stress in hepatocytes, leading to hepatocellular inflammation and apoptosis. Obese mice have impaired liver sarco/ER Ca2+-ATPase (SERCA) function, which normally maintains intracellular calcium homeostasis by transporting Ca2+ ions from the cytoplasm to the ER. We hypothesized that restoration of SERCA activity would improve diet-induced steatohepatitis in mice by limiting ER stress and mitochondrial dysfunction. WT and melanocortin-4 receptor KO (Mc4r-/-) mice were placed on either chow or Western diet (WD) for 8 weeks. Half of the WD-fed mice were administered CDN1163 to activate SERCA, which reduced liver fibrosis and inflammation. SERCA activation also restored glucose tolerance and insulin sensitivity, improved histological markers of metabolic dysfunction-associated steatohepatitis, increased expression of antioxidant enzymes, and decreased expression of oxidative stress and ER stress genes. CDN1163 decreased hepatic citric acid cycle flux and liver pyruvate cycling, enhanced expression of mitochondrial respiratory genes, and shifted hepatocellular [NADH]/[NAD+] and [NADPH]/[NADP+] ratios to a less oxidized state, which was associated with elevated PUFA content of liver lipids. In sum, the data demonstrate that pharmacological SERCA activation limits metabolic dysfunction-associated steatotic liver disease progression and prevents metabolic dysfunction induced by WD feeding in mice.
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Affiliation(s)
- Tomasz K Bednarski
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA
| | - Mohsin Rahim
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA
| | - Clinton M Hasenour
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA
| | - Deveena R Banerjee
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Irina A Trenary
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
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3
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Hilovsky D, Hartsell J, Young JD, Liu X. Stable Isotope Tracing Analysis in Cancer Research: Advancements and Challenges in Identifying Dysregulated Cancer Metabolism and Treatment Strategies. Metabolites 2024; 14:318. [PMID: 38921453 PMCID: PMC11205609 DOI: 10.3390/metabo14060318] [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: 05/07/2024] [Revised: 05/13/2024] [Accepted: 05/28/2024] [Indexed: 06/27/2024] Open
Abstract
Metabolic reprogramming is a hallmark of cancer, driving the development of therapies targeting cancer metabolism. Stable isotope tracing has emerged as a widely adopted tool for monitoring cancer metabolism both in vitro and in vivo. Advances in instrumentation and the development of new tracers, metabolite databases, and data analysis tools have expanded the scope of cancer metabolism studies across these scales. In this review, we explore the latest advancements in metabolic analysis, spanning from experimental design in stable isotope-labeling metabolomics to sophisticated data analysis techniques. We highlight successful applications in cancer research, particularly focusing on ongoing clinical trials utilizing stable isotope tracing to characterize disease progression, treatment responses, and potential mechanisms of resistance to anticancer therapies. Furthermore, we outline key challenges and discuss potential strategies to address them, aiming to enhance our understanding of the biochemical basis of cancer metabolism.
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Affiliation(s)
- Dalton Hilovsky
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA; (D.H.); (J.H.)
| | - Joshua Hartsell
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA; (D.H.); (J.H.)
| | - Jamey D. Young
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37212, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37212, USA
| | - Xiaojing Liu
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA; (D.H.); (J.H.)
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Deja S, Fletcher JA, Kim CW, Kucejova B, Fu X, Mizerska M, Villegas M, Pudelko-Malik N, Browder N, Inigo-Vollmer M, Menezes CJ, Mishra P, Berglund ED, Browning JD, Thyfault JP, Young JD, Horton JD, Burgess SC. Hepatic malonyl-CoA synthesis restrains gluconeogenesis by suppressing fat oxidation, pyruvate carboxylation, and amino acid availability. Cell Metab 2024; 36:1088-1104.e12. [PMID: 38447582 PMCID: PMC11081827 DOI: 10.1016/j.cmet.2024.02.004] [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: 02/01/2023] [Revised: 12/10/2023] [Accepted: 02/09/2024] [Indexed: 03/08/2024]
Abstract
Acetyl-CoA carboxylase (ACC) promotes prandial liver metabolism by producing malonyl-CoA, a substrate for de novo lipogenesis and an inhibitor of CPT-1-mediated fat oxidation. We report that inhibition of ACC also produces unexpected secondary effects on metabolism. Liver-specific double ACC1/2 knockout (LDKO) or pharmacologic inhibition of ACC increased anaplerosis, tricarboxylic acid (TCA) cycle intermediates, and gluconeogenesis by activating hepatic CPT-1 and pyruvate carboxylase flux in the fed state. Fasting should have marginalized the role of ACC, but LDKO mice maintained elevated TCA cycle intermediates and preserved glycemia during fasting. These effects were accompanied by a compensatory induction of proteolysis and increased amino acid supply for gluconeogenesis, which was offset by increased protein synthesis during feeding. Such adaptations may be related to Nrf2 activity, which was induced by ACC inhibition and correlated with fasting amino acids. The findings reveal unexpected roles for malonyl-CoA synthesis in liver and provide insight into the broader effects of pharmacologic ACC inhibition.
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Affiliation(s)
- Stanislaw Deja
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Justin A Fletcher
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Clinical Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Chai-Wan Kim
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Blanka Kucejova
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Xiaorong Fu
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Monika Mizerska
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Morgan Villegas
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Natalia Pudelko-Malik
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Nicholas Browder
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Melissa Inigo-Vollmer
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Cameron J Menezes
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Prashant Mishra
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Eric D Berglund
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Jeffrey D Browning
- Department of Clinical Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - John P Thyfault
- Departments of Cell Biology and Physiology, Internal Medicine and KU Diabetes Institute, Kansas Medical Center, Kansas City, KS, USA
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37235, USA
| | - Jay D Horton
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA.
| | - Shawn C Burgess
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA.
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Martino MR, Habibi M, Ferguson D, Brookheart RT, Thyfault JP, Meyer GA, Lantier L, Hughey CC, Finck BN. Disruption of hepatic mitochondrial pyruvate and amino acid metabolism impairs gluconeogenesis and endurance exercise capacity in mice. Am J Physiol Endocrinol Metab 2024; 326:E515-E527. [PMID: 38353639 PMCID: PMC11193532 DOI: 10.1152/ajpendo.00258.2023] [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: 08/16/2023] [Revised: 01/25/2024] [Accepted: 02/08/2024] [Indexed: 02/23/2024]
Abstract
Exercise robustly increases the glucose demands of skeletal muscle. This demand is met by not only muscle glycogenolysis but also accelerated liver glucose production from hepatic glycogenolysis and gluconeogenesis to fuel mechanical work and prevent hypoglycemia during exercise. Hepatic gluconeogenesis during exercise is dependent on highly coordinated responses within and between muscle and liver. Specifically, exercise increases the rate at which gluconeogenic precursors such as pyruvate/lactate or amino acids are delivered from muscle to the liver, extracted by the liver, and channeled into glucose. Herein, we examined the effects of interrupting hepatic gluconeogenic efficiency and capacity on exercise performance by deleting mitochondrial pyruvate carrier 2 (MPC2) and/or alanine transaminase 2 (ALT2) in the liver of mice. We found that deletion of MPC2 or ALT2 alone did not significantly affect time to exhaustion or postexercise glucose concentrations in treadmill exercise tests, but mice lacking both MPC2 and ALT2 in hepatocytes (double knockout, DKO) reached exhaustion faster and exhibited lower circulating glucose during and after exercise. Use of 2H/1³C metabolic flux analyses demonstrated that DKO mice exhibited lower endogenous glucose production owing to decreased glycogenolysis and gluconeogenesis at rest and during exercise. Decreased gluconeogenesis was accompanied by lower anaplerotic, cataplerotic, and TCA cycle fluxes. Collectively, these findings demonstrate that the transition of the liver to the gluconeogenic mode is critical for preventing hypoglycemia and sustaining performance during exercise. The results also illustrate the need for interorgan cross talk during exercise as described by the Cahill and Cori cycles.NEW & NOTEWORTHY Martino and colleagues examined the effects of inhibiting hepatic gluconeogenesis on exercise performance and systemic metabolism during treadmill exercise in mice. Combined inhibition of gluconeogenesis from lactate/pyruvate and alanine impaired exercise endurance and led to hypoglycemia during and after exercise. In contrast, suppressing either pyruvate-mediated or alanine-mediated gluconeogenesis alone had no effect on these parameters. These findings provide new insight into the molecular nodes that coordinate the metabolic responses of muscle and liver during exercise.
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Affiliation(s)
- Michael R Martino
- Division of Nutritional Sciences and Obesity Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Mohammad Habibi
- Division of Nutritional Sciences and Obesity Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Daniel Ferguson
- Division of Nutritional Sciences and Obesity Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Rita T Brookheart
- Division of Nutritional Sciences and Obesity Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States
| | - John P Thyfault
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, Missouri, United States
| | - Gretchen A Meyer
- Department of Medicine, Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Louise Lantier
- Department of Molecular Physiology and Biophysics, Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Curtis C Hughey
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, United States
| | - Brian N Finck
- Division of Nutritional Sciences and Obesity Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States
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Kasarla SS, Flocke V, Saw NMT, Fecke A, Sickmann A, Gunzer M, Flögel U, Phapale P. In-vivo tracking of deuterium metabolism in mouse organs using LC-MS/MS. J Chromatogr A 2024; 1717:464691. [PMID: 38301333 DOI: 10.1016/j.chroma.2024.464691] [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: 11/09/2023] [Revised: 01/26/2024] [Accepted: 01/27/2024] [Indexed: 02/03/2024]
Abstract
Mass spectrometry-based metabolomics with stable isotope labeling (SIL) is an established tool for sensitive and precise analyses of tissue metabolism, its flux, and pathway activities in diverse models of physiology and disease. Despite the simplicity and broad applicability of deuterium (2H)-labeled precursors for tracing metabolic pathways with minimal biological perturbations, they are rarely employed in LC-MS/MS-guided metabolomics. In this study, we have developed a LC-MS/MS-guided workflow to trace deuterium metabolism in mouse organs following 2H7 -glucose infusion. The workflow includes isotopically labeled glucose infusion, mouse organ isolation and metabolite extraction, zwitterion-based hydrophilic interaction liquid chromatography (HILIC) coupled to high-resolution tandem mass spectrometry, targeted data acquisition for sensitive detection of deuterated metabolites, a spectral library of over 400 metabolite standards, and multivariate data analysis with pathway mapping. The optimized method was validated for matrix effects, normalization, and quantification to provide both tissue metabolomics and tracking the in-vivo metabolic fate of deuterated glucose through key metabolic pathways. We quantified more than 100 metabolites in five major mouse organ tissues (liver, kidney, brain, brown adipose tissue, and heart). Furthermore, we mapped isotopologues of deuterated metabolites from glycolysis, tricarboxylic acid (TCA) cycle, and amino acid pathways, which are significant for studying both health and various diseases. This study will open new avenues in LC-MS based analysis of 2H-labeled tissue metabolism research in animal models and clinical settings.
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Affiliation(s)
- Siva Swapna Kasarla
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Otto-Hahn-Str. 6b, Dortmund 44227, Germany
| | - Vera Flocke
- Experimental Cardiovascular Imaging, Institute for Molecular Cardiology, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany
| | - Nay Min Thaw Saw
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Otto-Hahn-Str. 6b, Dortmund 44227, Germany
| | - Antonia Fecke
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Otto-Hahn-Str. 6b, Dortmund 44227, Germany
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Otto-Hahn-Str. 6b, Dortmund 44227, Germany
| | - Matthias Gunzer
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Otto-Hahn-Str. 6b, Dortmund 44227, Germany; Institute for Experimental Immunology and Imaging, University Hospital, University Duisburg-Essen, Essen 45122, Germany
| | - Ulrich Flögel
- Experimental Cardiovascular Imaging, Institute for Molecular Cardiology, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Düsseldorf 40225, Germany
| | - Prasad Phapale
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Otto-Hahn-Str. 6b, Dortmund 44227, Germany.
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Hughey CC, Bracy DP, Rome FI, Goelzer M, Donahue EP, Viollet B, Foretz M, Wasserman DH. Exercise training adaptations in liver glycogen and glycerolipids require hepatic AMP-activated protein kinase in mice. Am J Physiol Endocrinol Metab 2024; 326:E14-E28. [PMID: 37938177 PMCID: PMC11193517 DOI: 10.1152/ajpendo.00289.2023] [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: 09/01/2023] [Revised: 11/06/2023] [Accepted: 11/06/2023] [Indexed: 11/09/2023]
Abstract
Regular exercise elicits adaptations in glucose and lipid metabolism that allow the body to meet energy demands of subsequent exercise bouts more effectively and mitigate metabolic diseases including fatty liver. Energy discharged during the acute exercise bouts that comprise exercise training may be a catalyst for liver adaptations. During acute exercise, liver glycogenolysis and gluconeogenesis are accelerated to supply glucose to working muscle. Lower liver energy state imposed by gluconeogenesis and related pathways activates AMP-activated protein kinase (AMPK), which conserves ATP partly by promoting lipid oxidation. This study tested the hypothesis that AMPK is necessary for liver glucose and lipid adaptations to training. Liver-specific AMPKα1α2 knockout (AMPKα1α2fl/fl+AlbCre) mice and littermate controls (AMPKα1α2fl/fl) completed sedentary and exercise training protocols. Liver nutrient fluxes were quantified at rest or during acute exercise following training. Liver metabolites and molecular regulators of metabolism were assessed. Training increased liver glycogen in AMPKα1α2fl/fl mice, but not in AMPKα1α2fl/fl+AlbCre mice. The inability to increase glycogen led to lower glycogenolysis, glucose production, and circulating glucose during acute exercise in trained AMPKα1α2fl/fl+AlbCre mice. Deletion of AMPKα1α2 attenuated training-induced declines in liver diacylglycerides. In particular, training lowered the concentration of unsaturated and elongated fatty acids comprising diacylglycerides in AMPKα1α2fl/fl mice, but not in AMPKα1α2fl/fl+AlbCre mice. Training increased liver triacylglycerides and the desaturation and elongation of fatty acids in triacylglycerides of AMPKα1α2fl/fl+AlbCre mice. These lipid responses were independent of differences in tricarboxylic acid cycle fluxes. In conclusion, AMPK is required for liver training adaptations that are critical to glucose and lipid metabolism.NEW & NOTEWORTHY This study shows that the energy sensor and transducer, AMP-activated protein kinase (AMPK), is necessary for an exercise training-induced: 1) increase in liver glycogen that is necessary for accelerated glycogenolysis during exercise, 2) decrease in liver glycerolipids independent of tricarboxylic acid (TCA) cycle flux, and 3) decline in the desaturation and elongation of fatty acids comprising liver diacylglycerides. The mechanisms defined in these studies have implications for use of regular exercise or AMPK-activators in patients with fatty liver.
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Affiliation(s)
- Curtis C Hughey
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, United States
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Deanna P Bracy
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
- Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, Tennessee, United States
| | - Ferrol I Rome
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, United States
| | - Mickael Goelzer
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - E Patrick Donahue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Benoit Viollet
- Université Paris Cité, CNRS, Inserm, Institut Cochin, Paris, France
| | - Marc Foretz
- Université Paris Cité, CNRS, Inserm, Institut Cochin, Paris, France
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
- Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, Tennessee, United States
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8
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Lin TY, Ramsamooj S, Perrier T, Liberatore K, Lantier L, Vasan N, Karukurichi K, Hwang SK, Kesicki EA, Kastenhuber ER, Wiederhold T, Yaron TM, Huntsman EM, Zhu M, Ma Y, Paddock MN, Zhang G, Hopkins BD, McGuinness O, Schwartz RE, Ersoy BA, Cantley LC, Johnson JL, Goncalves MD. Epinephrine inhibits PI3Kα via the Hippo kinases. Cell Rep 2023; 42:113535. [PMID: 38060450 PMCID: PMC10809223 DOI: 10.1016/j.celrep.2023.113535] [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: 08/25/2022] [Revised: 10/23/2023] [Accepted: 11/16/2023] [Indexed: 12/30/2023] Open
Abstract
The phosphoinositide 3-kinase p110α is an essential mediator of insulin signaling and glucose homeostasis. We interrogated the human serine, threonine, and tyrosine kinome to search for novel regulators of p110α and found that the Hippo kinases phosphorylate p110α at T1061, which inhibits its activity. This inhibitory state corresponds to a conformational change of a membrane-binding domain on p110α, which impairs its ability to engage membranes. In human primary hepatocytes, cancer cell lines, and rodent tissues, activation of the Hippo kinases MST1/2 using forskolin or epinephrine is associated with phosphorylation of T1061 and inhibition of p110α, impairment of downstream insulin signaling, and suppression of glycolysis and glycogen synthesis. These changes are abrogated when MST1/2 are genetically deleted or inhibited with small molecules or if the T1061 is mutated to alanine. Our study defines an inhibitory pathway of PI3K signaling and a link between epinephrine and insulin signaling.
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Affiliation(s)
- Ting-Yu Lin
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Weill Cornell Graduate School of Medical Sciences, New York, NY 10021, USA
| | - Shakti Ramsamooj
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Division of Endocrinology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Tiffany Perrier
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Division of Endocrinology, Weill Cornell Medicine, New York, NY 10021, USA
| | | | - Louise Lantier
- Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Neil Vasan
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | | | - Seo-Kyoung Hwang
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Division of Endocrinology, Weill Cornell Medicine, New York, NY 10021, USA
| | | | | | | | - Tomer M Yaron
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Englander Institute for Precision Medicine, Institute for Computational Biomedicine, Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065, USA
| | - Emily M Huntsman
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Englander Institute for Precision Medicine, Institute for Computational Biomedicine, Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065, USA
| | - Mengmeng Zhu
- Proteomics and Metabolomics Core Facility, Weill Cornell Medicine, New York, NY 10021, USA
| | - Yilun Ma
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | - Marcia N Paddock
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | - Guoan Zhang
- Proteomics and Metabolomics Core Facility, Weill Cornell Medicine, New York, NY 10021, USA
| | | | - Owen McGuinness
- Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Robert E Schwartz
- Division of Gastroenterology & Hepatology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Baran A Ersoy
- Division of Gastroenterology & Hepatology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Lewis C Cantley
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | - Jared L Johnson
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA.
| | - Marcus D Goncalves
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Division of Endocrinology, Weill Cornell Medicine, New York, NY 10021, USA.
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9
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Nurjanah S, Gerding A, Vieira-Lara MA, Evers B, Langelaar-Makkinje M, Spiekerkoetter U, Bakker BM, Tucci S. Heptanoate Improves Compensatory Mechanism of Glucose Homeostasis in Mitochondrial Long-Chain Fatty Acid Oxidation Defect. Nutrients 2023; 15:4689. [PMID: 37960342 PMCID: PMC10649308 DOI: 10.3390/nu15214689] [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: 09/22/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023] Open
Abstract
Defects in mitochondrial fatty acid β-oxidation (FAO) impair metabolic flexibility, which is an essential process for energy homeostasis. Very-long-chain acyl-CoA dehydrogenase (VLCADD; OMIM 609575) deficiency is the most common long-chain mitochondrial FAO disorder presenting with hypoglycemia as a common clinical manifestation. To prevent hypoglycemia, triheptanoin-a triglyceride composed of three heptanoates (C7) esterified with a glycerol backbone-can be used as a dietary treatment, since it is metabolized into precursors for gluconeogenesis. However, studies investigating the effect of triheptanoin on glucose homeostasis are limited. To understand the role of gluconeogenesis in the pathophysiology of long-chain mitochondrial FAO defects, we injected VLCAD-deficient (VLCAD-/-) mice with 13C3-glycerol in the presence and absence of heptanoate (C7). The incorporation of 13C3-glycerol into blood glucose was higher in VLCAD-/- mice than in WT mice, whereas the difference disappeared in the presence of C7. The result correlates with 13C enrichment of liver metabolites in VLCAD-/- mice. In contrast, the C7 bolus significantly decreased the 13C enrichment. These data suggest that the increased contribution of gluconeogenesis to the overall glucose production in VLCAD-/- mice increases the need for gluconeogenesis substrate, thereby avoiding hypoglycemia. Heptanoate is a suitable substrate to induce glucose production in mitochondrial FAO defect.
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Affiliation(s)
- Siti Nurjanah
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Centre, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany (U.S.)
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Albert Gerding
- Laboratory of Pediatrics, Systems Medicine of Metabolism and Signaling, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands (M.L.-M.)
- Laboratory of Metabolic Diseases, Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands
| | - Marcel A. Vieira-Lara
- Laboratory of Pediatrics, Systems Medicine of Metabolism and Signaling, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands (M.L.-M.)
| | - Bernard Evers
- Laboratory of Pediatrics, Systems Medicine of Metabolism and Signaling, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands (M.L.-M.)
| | - Miriam Langelaar-Makkinje
- Laboratory of Pediatrics, Systems Medicine of Metabolism and Signaling, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands (M.L.-M.)
| | - Ute Spiekerkoetter
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Centre, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany (U.S.)
| | - Barbara M. Bakker
- Laboratory of Pediatrics, Systems Medicine of Metabolism and Signaling, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands (M.L.-M.)
| | - Sara Tucci
- Pharmacy, Medical Center, University of Freiburg, 79106 Freiburg, Germany
- G.E.R.N. Research Center for Tissue Replacement, Regeneration & Neogenesis, Department of Prosthetic Dentistry, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
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10
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Vázquez-Borrego MC, Del Río-Moreno M, Pyatkov M, Sarmento-Cabral A, Mahmood M, Pelke N, Wnek M, Cordoba-Chacon J, Waxman DJ, Puchowicz MA, McGuinness OP, Kineman RD. Direct and systemic actions of growth hormone receptor (GHR)-signaling on hepatic glycolysis, de novo lipogenesis and insulin sensitivity, associated with steatosis. Metabolism 2023; 144:155589. [PMID: 37182789 PMCID: PMC10843389 DOI: 10.1016/j.metabol.2023.155589] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/28/2023] [Accepted: 05/08/2023] [Indexed: 05/16/2023]
Abstract
BACKGROUND Evidence is accumulating that growth hormone (GH) protects against the development of steatosis and progression of non-alcoholic fatty liver disease (NAFLD). GH may control steatosis indirectly by altering systemic insulin sensitivity and substrate delivery to the liver and/or by the direct actions of GH on hepatocyte function. APPROACH To better define the hepatocyte-specific role of GH receptor (GHR) signaling on regulating steatosis, we used a mouse model with adult-onset, hepatocyte-specific GHR knockdown (aHepGHRkd). To prevent the reduction in circulating insulin-like growth factor 1 (IGF1) and the subsequent increase in GH observed after aHepGHRkd, subsets of aHepGHRkd mice were treated with adeno-associated viral vectors (AAV) driving hepatocyte-specific expression of IGF1 or a constitutively active form of STAT5b (STAT5bCA). The impact of hepatocyte-specific modulation of GHR, IGF1 and STAT5b on carbohydrate and lipid metabolism was studied across multiple nutritional states and in the context of hyperinsulinemic:euglycemic clamps. RESULTS Chow-fed male aHepGHRkd mice developed steatosis associated with an increase in hepatic glucokinase (GCK) and ketohexokinase (KHK) expression and de novo lipogenesis (DNL) rate, in the post-absorptive state and in response to refeeding after an overnight fast. The aHepGHRkd-associated increase in hepatic KHK, but not GCK and steatosis, was dependent on hepatocyte expression of carbohydrate response element binding protein (ChREBP), in re-fed mice. Interestingly, under clamp conditions, aHepGHRkd also increased the rate of DNL and expression of GCK and KHK, but impaired insulin-mediated suppression of hepatic glucose production, without altering plasma NEFA levels. These effects were normalized with AAV-mediated hepatocyte expression of IGF1 or STAT5bCA. Comparison of the impact of AAV-mediated hepatocyte IGF1 versus STAT5bCA in aHepGHRkd mice across multiple nutritional states, indicated the restorative actions of IGF1 are indirect, by improving systemic insulin sensitivity, independent of changes in the liver transcriptome. In contrast, the actions of STAT5b are due to the combined effects of raising IGF1 and direct alterations in the hepatocyte gene program that may involve suppression of BCL6 and FOXO1 activity. However, the direct and IGF1-dependent actions of STAT5b cannot fully account for enhanced GCK activity and lipogenic gene expression observed after aHepGHRkd, suggesting other GHR-mediated signals are involved. CONCLUSION These studies demonstrate hepatocyte GHR-signaling controls hepatic glycolysis, DNL, steatosis and hepatic insulin sensitivity indirectly (via IGF1) and directly (via STAT5b). The relative contribution of these indirect and direct actions of GH on hepatocytes is modified by insulin and nutrient availability. These results improve our understanding of the physiologic actions of GH on regulating adult metabolism to protect against NAFLD progression.
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Affiliation(s)
- Mari C Vázquez-Borrego
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Mercedes Del Río-Moreno
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Maxim Pyatkov
- Department of Biology & Bioinformatics Program, Boston University, Boston, MA, United States of America
| | - André Sarmento-Cabral
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Mariyah Mahmood
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Natalie Pelke
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Magdalena Wnek
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Jose Cordoba-Chacon
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - David J Waxman
- Department of Biology & Bioinformatics Program, Boston University, Boston, MA, United States of America
| | - Michelle A Puchowicz
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States of America
| | - Owen P McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States of America
| | - Rhonda D Kineman
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America.
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11
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Moiz B, Sriram G, Clyne AM. Interpreting metabolic complexity via isotope-assisted metabolic flux analysis. Trends Biochem Sci 2023; 48:553-567. [PMID: 36863894 PMCID: PMC10182253 DOI: 10.1016/j.tibs.2023.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 01/22/2023] [Accepted: 02/03/2023] [Indexed: 03/04/2023]
Abstract
Isotope-assisted metabolic flux analysis (iMFA) is a powerful method to mathematically determine the metabolic fluxome from experimental isotope labeling data and a metabolic network model. While iMFA was originally developed for industrial biotechnological applications, it is increasingly used to analyze eukaryotic cell metabolism in physiological and pathological states. In this review, we explain how iMFA estimates the intracellular fluxome, including data and network model (inputs), the optimization-based data fitting (process), and the flux map (output). We then describe how iMFA enables analysis of metabolic complexities and discovery of metabolic pathways. Our goal is to expand the use of iMFA in metabolism research, which is essential to maximizing the impact of metabolic experiments and continuing to advance iMFA and biocomputational techniques.
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Affiliation(s)
- Bilal Moiz
- Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Ganesh Sriram
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742, USA
| | - Alisa Morss Clyne
- Department of Bioengineering, University of Maryland, College Park, MD 20742, USA.
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12
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Lee G, Lee SM, Kim HU. A contribution of metabolic engineering to addressing medical problems: Metabolic flux analysis. Metab Eng 2023; 77:283-293. [PMID: 37075858 DOI: 10.1016/j.ymben.2023.04.008] [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: 02/04/2023] [Revised: 03/20/2023] [Accepted: 04/12/2023] [Indexed: 04/21/2023]
Abstract
Metabolic engineering has served as a systematic discipline for industrial biotechnology as it has offered systematic tools and methods for strain development and bioprocess optimization. Because these metabolic engineering tools and methods are concerned with the biological network of a cell with emphasis on metabolic network, they have also been applied to a range of medical problems where better understanding of metabolism has also been perceived to be important. Metabolic flux analysis (MFA) is a unique systematic approach initially developed in the metabolic engineering community, and has proved its usefulness and potential when addressing a range of medical problems. In this regard, this review discusses the contribution of MFA to addressing medical problems. For this, we i) provide overview of the milestones of MFA, ii) define two main branches of MFA, namely constraint-based reconstruction and analysis (COBRA) and isotope-based MFA (iMFA), and iii) present successful examples of their medical applications, including characterizing the metabolism of diseased cells and pathogens, and identifying effective drug targets. Finally, synergistic interactions between metabolic engineering and biomedical sciences are discussed with respect to MFA.
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Affiliation(s)
- GaRyoung Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Sang Mi Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hyun Uk Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea; BioProcess Engineering Research Center and BioInformatics Research Center, KAIST, Daejeon, 34141, Republic of Korea.
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13
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Shahryari M, Keller S, Meierhofer D, Wallach I, Safraou Y, Guo J, Marticorena Garcia SR, Braun J, Makowski MR, Sack I, Berndt N. On the relationship between metabolic capacities and in vivo viscoelastic properties of the liver. Front Bioeng Biotechnol 2023; 10:1042711. [PMID: 36698634 PMCID: PMC9868178 DOI: 10.3389/fbioe.2022.1042711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 12/21/2022] [Indexed: 01/11/2023] Open
Abstract
The liver is the central metabolic organ. It constantly adapts its metabolic capacity to current physiological requirements. However, the relationship between tissue structure and hepatic function is incompletely understood; this results in a lack of diagnostic markers in medical imaging that can provide information about the liver's metabolic capacity. Therefore, using normal rabbit livers, we combined magnetic resonance elastography (MRE) with proteomics-based kinetic modeling of central liver metabolism to investigate the potential role of MRE for predicting the liver's metabolic function in vivo. Nineteen New Zealand white rabbits were investigated by multifrequency MRE and positron emission tomography (PET). This yielded maps of shear wave speed (SWS), penetration rate (PR) and standardized uptake value (SUV). Proteomic analysis was performed after the scans. Hepatic metabolic functions were assessed on the basis of the HEPATOKIN1 model in combination with a model of hepatic lipid-droplet metabolism using liquid chromatography-mass spectrometry. Our results showed marked differences between individual livers in both metabolic functions and stiffness properties, though not in SUV. When livers were divided into 'stiff' and 'soft' subgroups (cutoff SWS = 1.6 m/s), stiff livers showed a lower capacity for triacylglycerol storage, while at the same time showing an increased capacity for gluconeogenesis and cholesterol synthesis. Furthermore, SWS was correlated with gluconeogenesis and PR with urea production and glutamine exchange. In conclusion, our study indicates a close relationship between the viscoelastic properties of the liver and metabolic function. This could be used in future studies to predict non-invasively the functional reserve capacity of the liver in patients.
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Affiliation(s)
- Mehrgan Shahryari
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Sarah Keller
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - David Meierhofer
- Mass Spectrometry Facility, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Iwona Wallach
- Institute of Computer-Assisted Cardiovascular Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Yasmine Safraou
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jing Guo
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Stephan R. Marticorena Garcia
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jürgen Braun
- Institute of Medical Informatics, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Marcus R. Makowski
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Faculty of Medicine, Munich, Germany
| | - Ingolf Sack
- Department of Radiology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Nikolaus Berndt
- Institute of Computer-Assisted Cardiovascular Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany,*Correspondence: Nikolaus Berndt,
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14
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Hubbard BT, LaMoia TE, Goedeke L, Gaspar RC, Galsgaard KD, Kahn M, Mason GF, Shulman GI. Q-Flux: A method to assess hepatic mitochondrial succinate dehydrogenase, methylmalonyl-CoA mutase, and glutaminase fluxes in vivo. Cell Metab 2023; 35:212-226.e4. [PMID: 36516861 PMCID: PMC9887731 DOI: 10.1016/j.cmet.2022.11.011] [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: 04/12/2022] [Revised: 09/14/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022]
Abstract
The mammalian succinate dehydrogenase (SDH) complex has recently been shown as capable of operating bidirectionally. Here, we develop a method (Q-Flux) capable of measuring absolute rates of both forward (VSDH(F)) and reverse (VSDH(R)) flux through SDH in vivo while also deconvoluting the amount of glucose derived from four discreet carbon sources in the liver. In validation studies, a mitochondrial uncoupler increased net SDH flux by >100% in awake rodents but also increased SDH cycling. During hyperglucagonemia, attenuated pyruvate cycling enhances phosphoenolpyruvate carboxykinase efficiency to drive increased gluconeogenesis, which is complemented by increased glutaminase (GLS) flux, methylmalonyl-CoA mutase (MUT) flux, and glycerol conversion to glucose. During hyperinsulinemic-euglycemic clamp, both pyruvate carboxylase and GLS are suppressed, while VSDH(R) is increased. Unstimulated MUT is a minor anaplerotic reaction but is readily induced by small amounts of propionate, which elicits glucagon-like metabolic rewiring. Taken together, Q-Flux yields a comprehensive picture of hepatic mitochondrial metabolism and should be broadly useful to researchers.
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Affiliation(s)
- Brandon T Hubbard
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Department of Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Traci E LaMoia
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Department of Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Leigh Goedeke
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA
| | - Rafael C Gaspar
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA
| | - Katrine D Galsgaard
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA
| | - Mario Kahn
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA
| | - Graeme F Mason
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT 06510, USA; Departments of Psychiatry & Biomedical Engineering, Yale School of Medicine, New Haven, CT 06510, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Department of Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT 06510, USA.
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15
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Rome FI, Shobert GL, Voigt WC, Stagg DB, Puchalska P, Burgess SC, Crawford PA, Hughey CC. Loss of hepatic phosphoenolpyruvate carboxykinase 1 dysregulates metabolic responses to acute exercise but enhances adaptations to exercise training in mice. Am J Physiol Endocrinol Metab 2023; 324:E9-E23. [PMID: 36351254 PMCID: PMC9799143 DOI: 10.1152/ajpendo.00222.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/07/2022] [Accepted: 11/07/2022] [Indexed: 11/10/2022]
Abstract
Acute exercise increases liver gluconeogenesis to supply glucose to working muscles. Concurrently, elevated liver lipid breakdown fuels the high energetic cost of gluconeogenesis. This functional coupling between liver gluconeogenesis and lipid oxidation has been proposed to underlie the ability of regular exercise to enhance liver mitochondrial oxidative metabolism and decrease liver steatosis in individuals with nonalcoholic fatty liver disease. Herein we tested whether repeated bouts of increased hepatic gluconeogenesis are necessary for exercise training to lower liver lipids. Experiments used diet-induced obese mice lacking hepatic phosphoenolpyruvate carboxykinase 1 (KO) to inhibit gluconeogenesis and wild-type (WT) littermates. 2H/13C metabolic flux analysis quantified glucose and mitochondrial oxidative fluxes in untrained mice at rest and during acute exercise. Circulating and tissue metabolite levels were determined during sedentary conditions, acute exercise, and refeeding postexercise. Mice also underwent 6 wk of treadmill running protocols to define hepatic and extrahepatic adaptations to exercise training. Untrained KO mice were unable to maintain euglycemia during acute exercise resulting from an inability to increase gluconeogenesis. Liver triacylglycerides were elevated after acute exercise and circulating β-hydroxybutyrate was higher during postexercise refeeding in untrained KO mice. In contrast, exercise training prevented liver triacylglyceride accumulation in KO mice. This was accompanied by pronounced increases in indices of skeletal muscle mitochondrial oxidative metabolism in KO mice. Together, these results show that hepatic gluconeogenesis is dispensable for exercise training to reduce liver lipids. This may be due to responses in ketone body metabolism and/or metabolic adaptations in skeletal muscle to exercise.NEW & NOTEWORTHY Exercise training reduces hepatic steatosis partly through enhanced hepatic terminal oxidation. During acute exercise, hepatic gluconeogenesis is elevated to match the heightened rate of muscle glucose uptake and maintain glucose homeostasis. It has been postulated that the hepatic energetic stress induced by elevating gluconeogenesis during acute exercise is a key stimulus underlying the beneficial metabolic responses to exercise training. This study shows that hepatic gluconeogenesis is not necessary for exercise training to lower liver lipids.
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Affiliation(s)
- Ferrol I Rome
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Gregory L Shobert
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - William C Voigt
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - David B Stagg
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota
| | - Patrycja Puchalska
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Shawn C Burgess
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Peter A Crawford
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota
| | - Curtis C Hughey
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
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16
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Nascentes Melo LM, Lesner NP, Sabatier M, Ubellacker JM, Tasdogan A. Emerging metabolomic tools to study cancer metastasis. Trends Cancer 2022; 8:988-1001. [PMID: 35909026 DOI: 10.1016/j.trecan.2022.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/24/2022] [Accepted: 07/06/2022] [Indexed: 12/24/2022]
Abstract
Metastasis is responsible for 90% of deaths in patients with cancer. Understanding the role of metabolism during metastasis has been limited by the development of robust and sensitive technologies that capture metabolic processes in metastasizing cancer cells. We discuss the current technologies available to study (i) metabolism in primary and metastatic cancer cells and (ii) metabolic interactions between cancer cells and the tumor microenvironment (TME) at different stages of the metastatic cascade. We identify advantages and disadvantages of each method and discuss how these tools and technologies will further improve our understanding of metastasis. Studies investigating the complex metabolic rewiring of different cells using state-of-the-art metabolomic technologies have the potential to reveal novel biological processes and therapeutic interventions for human cancers.
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Affiliation(s)
| | - Nicholas P Lesner
- Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Marie Sabatier
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Jessalyn M Ubellacker
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Alpaslan Tasdogan
- Department of Dermatology, University Hospital Essen and German Cancer Consortium, Partner Site, Essen, Germany.
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17
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Moiz B, Li A, Padmanabhan S, Sriram G, Clyne AM. Isotope-Assisted Metabolic Flux Analysis: A Powerful Technique to Gain New Insights into the Human Metabolome in Health and Disease. Metabolites 2022; 12:1066. [PMID: 36355149 PMCID: PMC9694183 DOI: 10.3390/metabo12111066] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 10/25/2022] [Accepted: 10/27/2022] [Indexed: 04/28/2024] Open
Abstract
Cell metabolism represents the coordinated changes in genes, proteins, and metabolites that occur in health and disease. The metabolic fluxome, which includes both intracellular and extracellular metabolic reaction rates (fluxes), therefore provides a powerful, integrated description of cellular phenotype. However, intracellular fluxes cannot be directly measured. Instead, flux quantification requires sophisticated mathematical and computational analysis of data from isotope labeling experiments. In this review, we describe isotope-assisted metabolic flux analysis (iMFA), a rigorous computational approach to fluxome quantification that integrates metabolic network models and experimental data to generate quantitative metabolic flux maps. We highlight practical considerations for implementing iMFA in mammalian models, as well as iMFA applications in in vitro and in vivo studies of physiology and disease. Finally, we identify promising new frontiers in iMFA which may enable us to fully unlock the potential of iMFA in biomedical research.
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Affiliation(s)
- Bilal Moiz
- Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Andrew Li
- Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Surya Padmanabhan
- Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Ganesh Sriram
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742, USA
| | - Alisa Morss Clyne
- Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
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18
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Affiliation(s)
- Julio E Ayala
- Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Diabetes Research Center, Vanderbilt University, Nashville, TN, USA
- Mouse Diabetes Clinic at Vanderbilt, Vanderbilt University, Nashville, TN, USA
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Louise Lantier
- Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Diabetes Research Center, Vanderbilt University, Nashville, TN, USA
- Mouse Diabetes Clinic at Vanderbilt, Vanderbilt University, Nashville, TN, USA
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Owen P McGuinness
- Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Diabetes Research Center, Vanderbilt University, Nashville, TN, USA
- Mouse Diabetes Clinic at Vanderbilt, Vanderbilt University, Nashville, TN, USA
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, USA
| | - David H Wasserman
- Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN, USA.
- Vanderbilt Diabetes Research Center, Vanderbilt University, Nashville, TN, USA.
- Mouse Diabetes Clinic at Vanderbilt, Vanderbilt University, Nashville, TN, USA.
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, USA.
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19
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Uematsu S, Ohno S, Tanaka KY, Hatano A, Kokaji T, Ito Y, Kubota H, Hironaka KI, Suzuki Y, Matsumoto M, Nakayama KI, Hirayama A, Soga T, Kuroda S. Multi-omics-based label-free metabolic flux inference reveals obesity-associated dysregulatory mechanisms in liver glucose metabolism. iScience 2022; 25:103787. [PMID: 35243212 PMCID: PMC8859528 DOI: 10.1016/j.isci.2022.103787] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 12/01/2021] [Accepted: 01/13/2022] [Indexed: 02/07/2023] Open
Abstract
Glucose homeostasis is maintained by modulation of metabolic flux. Enzymes and metabolites regulate the involved metabolic pathways. Dysregulation of glucose homeostasis is a pathological event in obesity. Analyzing metabolic pathways and the mechanisms contributing to obesity-associated dysregulation in vivo is challenging. Here, we introduce OMELET: Omics-Based Metabolic Flux Estimation without Labeling for Extended Trans-omic Analysis. OMELET uses metabolomic, proteomic, and transcriptomic data to identify relative changes in metabolic flux, and to calculate contributions of metabolites, enzymes, and transcripts to the changes in metabolic flux. By evaluating the livers of fasting ob/ob mice, we found that increased metabolic flux through gluconeogenesis resulted primarily from increased transcripts, whereas that through the pyruvate cycle resulted from both increased transcripts and changes in substrates of metabolic enzymes. With OMELET, we identified mechanisms underlying the obesity-associated dysregulation of metabolic flux in the liver. We developed OMELET to infer metabolic flux from label-free multi-omic data Contributions of metabolites, enzymes, and transcripts for flux were inferred Gluconeogenic flux increased in fasting ob/ob mice by increased transcripts Increased pyruvate cycle fluxes were led by increased transcripts and substrates
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Affiliation(s)
- Saori Uematsu
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Satoshi Ohno
- Molecular Genetic Research Laboratory, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.,Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kaori Y Tanaka
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Atsushi Hatano
- Department of Omics and Systems Biology, Graduate School of Medical and Dental Sciences, Niigata University, 757 Ichibancho, Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan
| | - Toshiya Kokaji
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuki Ito
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.,Division of Integrated Omics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Hiroyuki Kubota
- Division of Integrated Omics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Ken-Ichi Hironaka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yutaka Suzuki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Masaki Matsumoto
- Department of Omics and Systems Biology, Graduate School of Medical and Dental Sciences, Niigata University, 757 Ichibancho, Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan
| | - Keiichi I Nakayama
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Akiyoshi Hirayama
- Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata 997-0052, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata 997-0052, Japan
| | - Shinya Kuroda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.,Molecular Genetic Research Laboratory, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.,Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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20
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Glucose-6-phosphatase catalytic subunit 2 negatively regulates glucose oxidation and insulin secretion in pancreatic β-cells. J Biol Chem 2022; 298:101729. [PMID: 35176280 PMCID: PMC8941207 DOI: 10.1016/j.jbc.2022.101729] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 02/11/2022] [Accepted: 02/12/2022] [Indexed: 12/11/2022] Open
Abstract
Elevated fasting blood glucose (FBG) is associated with increased risks of developing type 2 diabetes (T2D) and cardiovascular-associated mortality. G6PC2 is predominantly expressed in islets, encodes a glucose-6-phosphatase catalytic subunit that converts glucose-6-phosphate (G6P) to glucose, and has been linked with variations in FBG in genome-wide association studies. Deletion of G6pc2 in mice has been shown to lower FBG without affecting fasting plasma insulin levels in vivo. At 5 mM glucose, pancreatic islets from G6pc2 knockout (KO) mice exhibit no glucose cycling, increased glycolytic flux, and enhanced glucose-stimulated insulin secretion (GSIS). However, the broader effects of G6pc2 KO on β-cell metabolism and redox regulation are unknown. Here we used CRISPR/Cas9 gene editing and metabolic flux analysis in βTC3 cells, a murine pancreatic β-cell line, to examine the role of G6pc2 in regulating glycolytic and mitochondrial fluxes. We found that deletion of G6pc2 led to ∼60% increases in glycolytic and citric acid cycle (CAC) fluxes at both 5 and 11 mM glucose concentrations. Furthermore, intracellular insulin content and GSIS were enhanced by approximately two-fold, along with increased cytosolic redox potential and reductive carboxylation flux. Normalization of fluxes relative to net glucose uptake revealed upregulation in two NADPH-producing pathways in the CAC. These results demonstrate that G6pc2 regulates GSIS by modulating not only glycolysis but also, independently, citric acid cycle activity in β-cells. Overall, our findings implicate G6PC2 as a potential therapeutic target for enhancing insulin secretion and lowering FBG, which could benefit individuals with prediabetes, T2D, and obesity.
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21
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Rome FI, Hughey CC. Disrupted Liver Oxidative Metabolism in Glycine N-Methyltransferase-Deficient Mice is Mitigated by Dietary Methionine Restriction. Mol Metab 2022; 58:101452. [PMID: 35121169 PMCID: PMC8866067 DOI: 10.1016/j.molmet.2022.101452] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 01/10/2022] [Accepted: 01/27/2022] [Indexed: 11/25/2022] Open
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22
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Rahim M, Ragavan M, Deja S, Merritt ME, Burgess SC, Young JD. INCA 2.0: A tool for integrated, dynamic modeling of NMR- and MS-based isotopomer measurements and rigorous metabolic flux analysis. Metab Eng 2022; 69:275-285. [PMID: 34965470 PMCID: PMC8789327 DOI: 10.1016/j.ymben.2021.12.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 12/17/2021] [Accepted: 12/22/2021] [Indexed: 01/03/2023]
Abstract
Metabolic flux analysis (MFA) combines experimental measurements and computational modeling to determine biochemical reaction rates in live biological systems. Advancements in analytical instrumentation, such as nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS), have facilitated chemical separation and quantification of isotopically enriched metabolites. However, no software packages have been previously described that can integrate isotopomer measurements from both MS and NMR analytical platforms and have the flexibility to estimate metabolic fluxes from either isotopic steady-state or dynamic labeling experiments. By applying physiologically relevant cardiac and hepatic metabolic models to assess NMR isotopomer measurements, we herein test and validate new modeling capabilities of our enhanced flux analysis software tool, INCA 2.0. We demonstrate that INCA 2.0 can simulate and regress steady-state 13C NMR datasets from perfused hearts with an accuracy comparable to other established flux assessment tools. Furthermore, by simulating the infusion of three different 13C acetate tracers, we show that MFA based on dynamic 13C NMR measurements can more precisely resolve cardiac fluxes compared to isotopically steady-state flux analysis. Finally, we show that estimation of hepatic fluxes using combined 13C NMR and MS datasets improves the precision of estimated fluxes by up to 50%. Overall, our results illustrate how the recently added NMR data modeling capabilities of INCA 2.0 can enable entirely new experimental designs that lead to improved flux resolution and can be applied to a wide range of biological systems and measurement time courses.
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Affiliation(s)
- Mohsin Rahim
- Department of Chemical and Biomolecular, Nashville, TN, 37212, USA
| | - Mukundan Ragavan
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Stanislaw Deja
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Matthew E Merritt
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Shawn C Burgess
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jamey D Young
- Department of Chemical and Biomolecular, Nashville, TN, 37212, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Engineering, Nashville, TN, 37212, USA.
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23
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Jain S, Barella LF, Wess J, Reitman ML, Jacobson KA. Adenosine A 1 receptor is dispensable for hepatocyte glucose metabolism and insulin sensitivity. Biochem Pharmacol 2021; 192:114739. [PMID: 34418353 PMCID: PMC8478863 DOI: 10.1016/j.bcp.2021.114739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 08/13/2021] [Accepted: 08/16/2021] [Indexed: 12/12/2022]
Abstract
Hepatic insulin resistance (IR) and enhanced hepatic glucose production (HGP) are key features of type 2 diabetes (T2D), contributing to fasting hyperglycemia. Adenosine receptors (ARs) are G protein-coupled and expressed in hepatocytes. Here, we explored the role of hepatic Gi/o-coupled A1AR on insulin resistance and glucose fluxes associated with obesity. We generated a mouse model with hepatocyte-specific deletion of A1AR (A1LΔ/Δ), which was compared with whole body knockout of A1AR or A1AR/A3AR (both Gi-coupled). Selective deletion of hepatic A1AR resulted in a modest improvement in insulin sensitivity. In addition, HFD A1LΔ/Δ mice showed decreased fasting glucose levels. Hyperinsulinemic-euglycemic clamp studies demonstrated enhanced insulin sensitivity with no change in HGP in HFD A1LΔ/Δ mice. Similar to A1LΔ/Δ, fasting blood glucose levels were significantly reduced in whole body A1Δ/Δ and A1Δ/ΔA3Δ/Δ compared to wild-type mice. Taken together, our data support the concept that blocking hepatic A1AR may decrease fasting blood glucose levels without directly affecting hepatocyte glucose metabolism and insulin sensitivity.
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Affiliation(s)
- Shanu Jain
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Luiz F Barella
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Marc L Reitman
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
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24
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Ragavan M, McLeod MA, Giacalone AG, Merritt ME. Hyperpolarized Dihydroxyacetone Is a Sensitive Probe of Hepatic Gluconeogenic State. Metabolites 2021; 11:441. [PMID: 34357335 PMCID: PMC8307483 DOI: 10.3390/metabo11070441] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/23/2021] [Accepted: 07/01/2021] [Indexed: 11/25/2022] Open
Abstract
Type II diabetes and pre-diabetes are widely prevalent among adults. Elevated serum glucose levels are commonly treated by targeting hepatic gluconeogenesis for downregulation. However, direct measurement of hepatic gluconeogenic capacity is accomplished only via tracer metabolism approaches that rely on multiple assumptions, and are clinically intractable due to expense and time needed for the studies. We previously introduced hyperpolarized (HP) [2-13C]dihydroxyacetone (DHA) as a sensitive detector of gluconeogenic potential, and showed that feeding and fasting produced robust changes in the ratio of detected hexoses (6C) to trioses (3C) in the perfused liver. To confirm that this ratio is robust in the setting of treatment and hormonal control, we used ex vivo perfused mouse livers from BLKS mice (glucagon treated and metformin treated), and db/db mice. We confirm that the ratio of signal intensities of 6C to 3C in 13C nuclear magnetic resonance spectra post HP DHA administration is sensitive to hepatic gluconeogenic state. This method is directly applicable in vivo and can be implemented with existing technologies without the need for substantial modifications.
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Affiliation(s)
| | | | | | - Matthew E. Merritt
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; (M.R.); (M.A.M.); (A.G.G.)
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25
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Rahim M, Hasenour CM, Bednarski TK, Hughey CC, Wasserman DH, Young JD. Multitissue 2H/13C flux analysis reveals reciprocal upregulation of renal gluconeogenesis in hepatic PEPCK-C-knockout mice. JCI Insight 2021; 6:e149278. [PMID: 34156032 PMCID: PMC8262479 DOI: 10.1172/jci.insight.149278] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The liver is the major source of glucose production during fasting under normal physiological conditions. However, the kidney may also contribute to maintaining glucose homeostasis in certain circumstances. To test the ability of the kidney to compensate for impaired hepatic glucose production in vivo, we developed a stable isotope approach to simultaneously quantify gluconeogenic and oxidative metabolic fluxes in the liver and kidney. Hepatic gluconeogenesis from phosphoenolpyruvate was disrupted via liver-specific knockout of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C; KO). 2H/13C isotopes were infused in fasted KO and WT littermate mice, and fluxes were estimated from isotopic measurements of tissue and plasma metabolites using a multicompartment metabolic model. Hepatic gluconeogenesis and glucose production were reduced in KO mice, yet whole-body glucose production and arterial glucose were unaffected. Glucose homeostasis was maintained by a compensatory rise in renal glucose production and gluconeogenesis. Renal oxidative metabolic fluxes of KO mice increased to sustain the energetic and metabolic demands of elevated gluconeogenesis. These results show the reciprocity of the liver and kidney in maintaining glucose homeostasis by coordinated regulation of gluconeogenic flux through PEPCK-C. Combining stable isotopes with mathematical modeling provides a versatile platform to assess multitissue metabolism in various genetic, pathophysiological, physiological, and pharmacological settings.
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Affiliation(s)
- Mohsin Rahim
- Department of Chemical and Biomolecular Engineering and
| | | | | | - Curtis C Hughey
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering and.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
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26
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Bednarski TK, Rahim M, Young JD. In vivo 2H/ 13C flux analysis in metabolism research. Curr Opin Biotechnol 2021; 71:1-8. [PMID: 34048994 DOI: 10.1016/j.copbio.2021.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/29/2021] [Accepted: 04/26/2021] [Indexed: 12/12/2022]
Abstract
Identifying the factors and mechanisms that regulate metabolism under normal and diseased states requires methods to quantify metabolic fluxes of live tissues within their physiological milieu. A number of recent developments have expanded the reach and depth of isotope-based in vivo flux analysis, which have in turn challenged existing dogmas in metabolism research. First, minimally invasive techniques of intravenous isotope infusion and sampling have advanced in vivo metabolic tracer studies in animal models and human subjects. Second, recent breakthroughs in analytical instrumentation have expanded the scope of isotope labeling measurements and reduced sample volume requirements. Third, innovative modeling approaches and publicly available software tools have facilitated rigorous analysis of sophisticated experimental designs involving multiple tracers and expansive metabolomics datasets. These developments have enabled comprehensive in vivo quantification of metabolic fluxes in specific tissues and have set the stage for integrated multi-tissue flux assays.
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Affiliation(s)
- Tomasz K Bednarski
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA
| | - Mohsin Rahim
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
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27
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Hasenour CM, Rahim M, Young JD. In Vivo Estimates of Liver Metabolic Flux Assessed by 13C-Propionate and 13C-Lactate Are Impacted by Tracer Recycling and Equilibrium Assumptions. Cell Rep 2021; 32:107986. [PMID: 32755580 PMCID: PMC7451222 DOI: 10.1016/j.celrep.2020.107986] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 06/01/2020] [Accepted: 07/13/2020] [Indexed: 01/08/2023] Open
Abstract
Isotope-based assessment of metabolic flux is achieved through a judicious balance of measurements and assumptions. Recent publications debate the validity of key assumptions used to model stable isotope labeling of liver metabolism in vivo. Here, we examine the controversy surrounding estimates of liver citric acid cycle and gluconeogenesis fluxes using a flexible modeling platform that enables rigorous testing of standard assumptions. Fasted C57BL/6J mice are infused with [13C3]lactate or [13C3]propionate isotopes, and hepatic fluxes are regressed using models with gradually increasing complexity and relaxed assumptions. We confirm that liver pyruvate cycling fluxes are incongruent between different 13C tracers in models with conventional assumptions. When models are expanded to include more labeling measurements and fewer constraining assumptions, however, liver pyruvate cycling is significant, and inconsistencies in hepatic flux estimates using [13C3]lactate and [13C3]propionate isotopes emanate, in part, from peripheral tracer recycling and incomplete isotope equilibration within the citric acid cycle.
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Affiliation(s)
- Clinton M Hasenour
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA
| | - Mohsin Rahim
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37235, USA.
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28
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In Vivo Estimation of Ketogenesis Using Metabolic Flux Analysis-Technical Aspects and Model Interpretation. Metabolites 2021; 11:metabo11050279. [PMID: 33924948 PMCID: PMC8146959 DOI: 10.3390/metabo11050279] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 01/26/2023] Open
Abstract
Ketogenesis occurs in liver mitochondria where acetyl-CoA molecules, derived from lipid oxidation, are condensed into acetoacetate (AcAc) and reduced to β-hydroxybutyrate (BHB). During carbohydrate scarcity, these two ketones are released into circulation at high rates and used as oxidative fuels in peripheral tissues. Despite their physiological relevance and emerging roles in a variety of diseases, endogenous ketone production is rarely measured in vivo using tracer approaches. Accurate determination of this flux requires a two-pool model, simultaneous BHB and AcAc tracers, and special consideration for the stability of the AcAc tracer and analyte. We describe the implementation of a two-pool model using a metabolic flux analysis (MFA) approach that simultaneously regresses liquid chromatography-tandem mass spectrometry (LC-MS/MS) ketone isotopologues and tracer infusion rates. Additionally, 1H NMR real-time reaction monitoring was used to evaluate AcAc tracer and analyte stability during infusion and sample analysis, which were critical for accurate flux calculations. The approach quantifies AcAc and BHB pool sizes and their rates of appearance, disposal, and exchange. Regression analysis provides confidence intervals and detects potential errors in experimental data. Complications for the physiological interpretation of individual ketone fluxes are discussed.
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29
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Pannala VR, Estes SK, Rahim M, Trenary I, O’Brien TP, Shiota C, Printz RL, Reifman J, Shiota M, Young JD, Wallqvist A. Toxicant-Induced Metabolic Alterations in Lipid and Amino Acid Pathways Are Predictive of Acute Liver Toxicity in Rats. Int J Mol Sci 2020; 21:ijms21218250. [PMID: 33158035 PMCID: PMC7663358 DOI: 10.3390/ijms21218250] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 02/07/2023] Open
Abstract
Liver disease and disorders associated with aberrant hepatocyte metabolism can be initiated via drug and environmental toxicant exposures. In this study, we tested the hypothesis that gene and metabolic profiling can reveal commonalities in liver response to different toxicants and provide the capability to identify early signatures of acute liver toxicity. We used Sprague Dawley rats and three classical hepatotoxicants: acetaminophen (2 g/kg), bromobenzene (0.4 g/kg), and carbon tetrachloride (0.3 g/kg), to identify early perturbations in liver metabolism after a single acute exposure dose. We measured changes in liver genes and plasma metabolites at two time points (5 and 10 h) and used genome-scale metabolic models to identify commonalities in liver responses across the three toxicants. We found strong correlations for gene and metabolic profiles between the toxicants, indicative of similarities in the liver response to toxicity. We identified several injury-specific pathways in lipid and amino acid metabolism that changed similarly across the three toxicants. Our findings suggest that several plasma metabolites in lipid and amino acid metabolism are strongly associated with the progression of liver toxicity, and as such, could be targeted and clinically assessed for their potential as early predictors of acute liver toxicity.
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Affiliation(s)
- Venkat R. Pannala
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, MD 21702, USA;
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD 20817, USA
- Correspondence: (V.R.P.); (J.D.Y.); (A.W.); Tel.: +1-301-619-1976 (V.R.P.); +1-615-343-4253 (J.D.Y.); +1-301-619-1989 (A.W.); Fax: +301-619-1983 (A.W. & V.R.P.); +615-343-7951 (J.D.Y.)
| | - Shanea K. Estes
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; (S.K.E.); (T.P.O.); (C.S.); (R.L.P.); (M.S.)
| | - Mohsin Rahim
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN 37232, USA; (M.R.); (I.T.)
| | - Irina Trenary
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN 37232, USA; (M.R.); (I.T.)
| | - Tracy P. O’Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; (S.K.E.); (T.P.O.); (C.S.); (R.L.P.); (M.S.)
| | - Chiyo Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; (S.K.E.); (T.P.O.); (C.S.); (R.L.P.); (M.S.)
| | - Richard L. Printz
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; (S.K.E.); (T.P.O.); (C.S.); (R.L.P.); (M.S.)
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, MD 21702, USA;
| | - Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; (S.K.E.); (T.P.O.); (C.S.); (R.L.P.); (M.S.)
| | - Jamey D. Young
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; (S.K.E.); (T.P.O.); (C.S.); (R.L.P.); (M.S.)
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN 37232, USA; (M.R.); (I.T.)
- Correspondence: (V.R.P.); (J.D.Y.); (A.W.); Tel.: +1-301-619-1976 (V.R.P.); +1-615-343-4253 (J.D.Y.); +1-301-619-1989 (A.W.); Fax: +301-619-1983 (A.W. & V.R.P.); +615-343-7951 (J.D.Y.)
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, MD 21702, USA;
- Correspondence: (V.R.P.); (J.D.Y.); (A.W.); Tel.: +1-301-619-1976 (V.R.P.); +1-615-343-4253 (J.D.Y.); +1-301-619-1989 (A.W.); Fax: +301-619-1983 (A.W. & V.R.P.); +615-343-7951 (J.D.Y.)
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30
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Hui S, Cowan AJ, Zeng X, Yang L, TeSlaa T, Li X, Bartman C, Zhang Z, Jang C, Wang L, Lu W, Rojas J, Baur J, Rabinowitz JD. Quantitative Fluxomics of Circulating Metabolites. Cell Metab 2020; 32:676-688.e4. [PMID: 32791100 PMCID: PMC7544659 DOI: 10.1016/j.cmet.2020.07.013] [Citation(s) in RCA: 152] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/06/2020] [Accepted: 07/20/2020] [Indexed: 12/20/2022]
Abstract
Mammalian organs are nourished by nutrients carried by the blood circulation. These nutrients originate from diet and internal stores, and can undergo various interconversions before their eventual use as tissue fuel. Here we develop isotope tracing, mass spectrometry, and mathematical analysis methods to determine the direct sources of circulating nutrients, their interconversion rates, and eventual tissue-specific contributions to TCA cycle metabolism. Experiments with fifteen nutrient tracers enabled extensive accounting for both circulatory metabolic cycles and tissue TCA inputs, across fed and fasted mice on either high-carbohydrate or ketogenic diet. We find that a majority of circulating carbon flux is carried by two major cycles: glucose-lactate and triglyceride-glycerol-fatty acid. Futile cycling through these pathways is prominent when dietary content of the associated nutrients is low, rendering internal metabolic activity robust to food choice. The presented in vivo flux quantification methods are broadly applicable to different physiological and disease states.
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Affiliation(s)
- Sheng Hui
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA; Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, 655 Huntington Avenue, Boston, MA 02115, USA.
| | - Alexis J Cowan
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Xianfeng Zeng
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Lifeng Yang
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Tara TeSlaa
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Xiaoxuan Li
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Caroline Bartman
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Zhaoyue Zhang
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Cholsoon Jang
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Lin Wang
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Wenyun Lu
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Jennifer Rojas
- Department of Physiology and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Boulevard, Philadelphia, PA 19104, USA
| | - Joseph Baur
- Department of Physiology and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Boulevard, Philadelphia, PA 19104, USA
| | - Joshua D Rabinowitz
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA.
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31
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Mechanism-based identification of plasma metabolites associated with liver toxicity. Toxicology 2020; 441:152493. [DOI: 10.1016/j.tox.2020.152493] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/01/2020] [Accepted: 05/08/2020] [Indexed: 12/25/2022]
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Boland ML, Laker RC, Mather K, Nawrocki A, Oldham S, Boland BB, Lewis H, Conway J, Naylor J, Guionaud S, Feigh M, Veidal SS, Lantier L, McGuinness OP, Grimsby J, Rondinone CM, Jermutus L, Larsen MR, Trevaskis JL, Rhodes CJ. Resolution of NASH and hepatic fibrosis by the GLP-1R/GcgR dual-agonist Cotadutide via modulating mitochondrial function and lipogenesis. Nat Metab 2020; 2:413-431. [PMID: 32478287 PMCID: PMC7258337 DOI: 10.1038/s42255-020-0209-6] [Citation(s) in RCA: 145] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Non-alcoholic fatty liver disease and steatohepatitis are highly associated with obesity and type 2 diabetes mellitus. Cotadutide, a GLP-1R/GcgR agonist, was shown to reduce blood glycemia, body weight and hepatic steatosis in patients with T2DM. Here, we demonstrate that the effects of Cotadutide to reduce body weight, food intake and improve glucose control are predominantly mediated through the GLP-1 signaling, while, its action on the liver to reduce lipid content, drive glycogen flux and improve mitochondrial turnover and function are directly mediated through Gcg signaling. This was confirmed by the identification of phosphorylation sites on key lipogenic and glucose metabolism enzymes in liver of mice treated with Cotadutide. Complementary metabolomic and transcriptomic analyses implicated lipogenic, fibrotic and inflammatory pathways, which are consistent with a unique therapeutic contribution of GcgR agonism by Cotadutide in vivo. Significantly, Cotadutide also alleviated fibrosis to a greater extent than Liraglutide or Obeticholic acid (OCA), despite adjusting dose to achieve similar weight loss in 2 preclinical mouse models of NASH. Thus Cotadutide, via direct hepatic (GcgR) and extra-hepatic (GLP-1R) effects, exerts multi-factorial improvement in liver function and is a promising therapeutic option for the treatment of steatohepatitis.
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Affiliation(s)
- Michelle L Boland
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Rhianna C Laker
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Karly Mather
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Arkadiusz Nawrocki
- Department of Biochemistry and Molecular Biology, PR group, University of Southern Denmark, Odense, Denmark
| | - Stephanie Oldham
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Brandon B Boland
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Hilary Lewis
- Research and Early Development, Oncology, AstraZeneca, Cambridge, UK
| | - James Conway
- Translational Sciences, AstraZeneca, Gaithersburg, MD, USA
| | - Jacqueline Naylor
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | | | | | | | - Louise Lantier
- Vanderbilt University Mouse Metabolic Phenotyping Center, Nashville, TN, USA
| | - Owen P McGuinness
- Vanderbilt University Mouse Metabolic Phenotyping Center, Nashville, TN, USA
| | - Joseph Grimsby
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Cristina M Rondinone
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Lutz Jermutus
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Martin R Larsen
- Department of Biochemistry and Molecular Biology, PR group, University of Southern Denmark, Odense, Denmark
| | - James L Trevaskis
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
- Gilead Sciences, Foster City, CA, USA
| | - Christopher J Rhodes
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA.
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Alemán JO. Can Brown Fat Activity Improve Cardiovascular Function and Atherosclerosis Risk in Humans? Arterioscler Thromb Vasc Biol 2020; 40:1020-1021. [PMID: 32320294 DOI: 10.1161/atvbaha.120.313978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- José O Alemán
- From the Division of Endocrinology, Department of Medicine, NYU Grossman School of Medicine, New York
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34
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Hasenour CM, Kennedy AJ, Bednarski T, Trenary IA, Eudy BJ, da Silva RP, Boyd KL, Young JD. Vitamin E does not prevent Western diet-induced NASH progression and increases metabolic flux dysregulation in mice. J Lipid Res 2020; 61:707-721. [PMID: 32086244 DOI: 10.1194/jlr.ra119000183] [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: 06/06/2019] [Revised: 02/18/2020] [Indexed: 12/13/2022] Open
Abstract
Fatty liver involves ectopic lipid accumulation and dysregulated hepatic oxidative metabolism, which can progress to a state of elevated inflammation and fibrosis referred to as nonalcoholic steatohepatitis (NASH). The factors that control progression from simple steatosis to NASH are not fully known. Here, we tested the hypothesis that dietary vitamin E (VitE) supplementation would prevent NASH progression and associated metabolic alterations induced by a Western diet (WD). Hyperphagic melanocortin-4 receptor-deficient (MC4R-/-) mice were fed chow, chow+VitE, WD, or WD+VitE starting at 8 or 20 weeks of age. All groups exhibited extensive hepatic steatosis by the end of the study (28 weeks of age). WD feeding exacerbated liver disease severity without inducing proportional changes in liver triglycerides. Eight weeks of WD accelerated liver pyruvate cycling, and 20 weeks of WD extensively upregulated liver glucose and oxidative metabolism assessed by 2H/13C flux analysis. VitE supplementation failed to reduce the histological features of NASH. Rather, WD+VitE increased the abundance and saturation of liver ceramides and accelerated metabolic flux dysregulation compared with 8 weeks of WD alone. In summary, VitE did not limit NASH pathogenesis in genetically obese mice, but instead increased some indicators of metabolic dysfunction.
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Affiliation(s)
- Clinton M Hasenour
- Departments of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN
| | - Arion J Kennedy
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Tomasz Bednarski
- Departments of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN
| | - Irina A Trenary
- Departments of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN
| | - Brandon J Eudy
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL
| | - Robin P da Silva
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL
| | - Kelli L Boyd
- Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, TN
| | - Jamey D Young
- Departments of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN; Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN; Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN. mailto:
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35
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Pannala VR, Vinnakota KC, Estes SK, Trenary I, OˈBrien TP, Printz RL, Papin JA, Reifman J, Oyama T, Shiota M, Young JD, Wallqvist A. Genome-Scale Model-Based Identification of Metabolite Indicators for Early Detection of Kidney Toxicity. Toxicol Sci 2020; 173:293-312. [PMID: 31722432 PMCID: PMC8000070 DOI: 10.1093/toxsci/kfz228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Identifying early indicators of toxicant-induced organ damage is critical to provide effective treatment. To discover such indicators and the underlying mechanisms of toxicity, we used gentamicin as an exemplar kidney toxicant and performed systematic perturbation studies in Sprague Dawley rats. We obtained high-throughput data 7 and 13 h after administration of a single dose of gentamicin (0.5 g/kg) and identified global changes in genes in the liver and kidneys, metabolites in the plasma and urine, and absolute fluxes in central carbon metabolism. We used these measured changes in genes in the liver and kidney as constraints to a rat multitissue genome-scale metabolic network model to investigate the mechanism of gentamicin-induced kidney toxicity and identify metabolites associated with changes in tissue gene expression. Our experimental analysis revealed that gentamicin-induced metabolic perturbations could be detected as early as 7 h postexposure. Our integrated systems-level analyses suggest that changes in kidney gene expression drive most of the significant metabolite alterations in the urine. The analyses thus allowed us to identify several significantly enriched injury-specific pathways in the kidney underlying gentamicin-induced toxicity, as well as metabolites in these pathways that could serve as potential early indicators of kidney damage.
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Affiliation(s)
- Venkat R Pannala
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, Maryland 21702
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland 20817
| | - Kalyan C Vinnakota
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, Maryland 21702
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland 20817
| | - Shanea K Estes
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Irina Trenary
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, Tennessee
| | - Tracy P OˈBrien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Richard L Printz
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jason A Papin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, Maryland 21702
| | - Tatsuya Oyama
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, Maryland 21702
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland 20817
| | - Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jamey D Young
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, Tennessee
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, Maryland 21702
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Deja S, Fu X, Fletcher JA, Kucejova B, Browning JD, Young JD, Burgess SC. Simultaneous tracers and a unified model of positional and mass isotopomers for quantification of metabolic flux in liver. Metab Eng 2019; 59:1-14. [PMID: 31891762 DOI: 10.1016/j.ymben.2019.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 12/12/2019] [Accepted: 12/21/2019] [Indexed: 12/23/2022]
Abstract
Computational models based on the metabolism of stable isotope tracers can yield valuable insight into the metabolic basis of disease. The complexity of these models is limited by the number of tracers and the ability to characterize tracer labeling in downstream metabolites. NMR spectroscopy is ideal for multiple tracer experiments since it precisely detects the position of tracer nuclei in molecules, but it lacks sensitivity for detecting low-concentration metabolites. GC-MS detects stable isotope mass enrichment in low-concentration metabolites, but lacks nuclei and positional specificity. We performed liver perfusions and in vivo infusions of 2H and 13C tracers, yielding complex glucose isotopomers that were assigned by NMR and fit to a newly developed metabolic model. Fluxes regressed from 2H and 13C NMR positional isotopomer enrichments served to validate GC-MS-based flux estimates obtained from the same experimental samples. NMR-derived fluxes were largely recapitulated by modeling the mass isotopomer distributions of six glucose fragment ions measured by GC-MS. Modest differences related to limited fragmentation coverage of glucose C1-C3 were identified, but fluxes such as gluconeogenesis, glycogenolysis, cataplerosis and TCA cycle flux were tightly correlated between the methods. Most importantly, modeling of GC-MS data could assign fluxes in primary mouse hepatocytes, an experiment that is impractical by 2H or 13C NMR.
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Affiliation(s)
- Stanislaw Deja
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Xiaorong Fu
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Justin A Fletcher
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Blanka Kucejova
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jeffrey D Browning
- Department of Clinical Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37235, USA.
| | - Shawn C Burgess
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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Allen DK, Young JD. Tracing metabolic flux through time and space with isotope labeling experiments. Curr Opin Biotechnol 2019; 64:92-100. [PMID: 31864070 PMCID: PMC7302994 DOI: 10.1016/j.copbio.2019.11.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/02/2019] [Accepted: 11/04/2019] [Indexed: 12/11/2022]
Abstract
Metabolism is dynamic and must function in context-specific ways to adjust to changes in the surrounding cellular and ecological environment. When isotopic tracers are used, metabolite flow (i.e. metabolic flux) can be quantified through biochemical networks to assess metabolic pathway operation. The cellular activities considered across multiple tissues and organs result in the observed phenotype and can be analyzed to discover emergent, whole-system properties of biology and elucidate misconceptions about network operation. However, temporal and spatial challenges remain significant hurdles and require novel approaches and creative solutions. We survey current investigations in higher plant and animal systems focused on dynamic isotope labeling experiments, spatially resolved measurement strategies, and observations from re-analysis of our own studies that suggest prospects for future work. Related discoveries will be necessary to push the frontier of our understanding of metabolism to suggest novel solutions to cure disease and feed a growing future world population.
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Affiliation(s)
- Doug K Allen
- United States Department of Agriculture-Agricultural Research Service, Plant Genetics Research Unit, 975 North Warson Road, St. Louis, MO 63132, United States; Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, United States.
| | - Jamey D Young
- Department of Chemical & Biomolecular Engineering, Vanderbilt University, PMB 351604, 2301 Vanderbilt Place, Nashville, TN 37235, United States; Department of Molecular Physiology & Biophysics, Vanderbilt University, PMB 351604, 2301 Vanderbilt Place, Nashville, TN 37235, United States.
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38
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Balcells C, Foguet C, Tarragó-Celada J, de Atauri P, Marin S, Cascante M. Tracing metabolic fluxes using mass spectrometry: Stable isotope-resolved metabolomics in health and disease. Trends Analyt Chem 2019. [DOI: 10.1016/j.trac.2018.12.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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39
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Cappel DA, Deja S, Duarte JAG, Kucejova B, Iñigo M, Fletcher JA, Fu X, Berglund ED, Liu T, Elmquist JK, Hammer S, Mishra P, Browning JD, Burgess SC. Pyruvate-Carboxylase-Mediated Anaplerosis Promotes Antioxidant Capacity by Sustaining TCA Cycle and Redox Metabolism in Liver. Cell Metab 2019; 29:1291-1305.e8. [PMID: 31006591 PMCID: PMC6585968 DOI: 10.1016/j.cmet.2019.03.014] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 01/12/2019] [Accepted: 03/26/2019] [Indexed: 01/09/2023]
Abstract
The hepatic TCA cycle supports oxidative and biosynthetic metabolism. This dual responsibility requires anaplerotic pathways, such as pyruvate carboxylase (PC), to generate TCA cycle intermediates necessary for biosynthesis without disrupting oxidative metabolism. Liver-specific PC knockout (LPCKO) mice were created to test the role of anaplerotic flux in liver metabolism. LPCKO mice have impaired hepatic anaplerosis, diminution of TCA cycle intermediates, suppressed gluconeogenesis, reduced TCA cycle flux, and a compensatory increase in ketogenesis and renal gluconeogenesis. Loss of PC depleted aspartate and compromised urea cycle function, causing elevated urea cycle intermediates and hyperammonemia. Loss of PC prevented diet-induced hyperglycemia and insulin resistance but depleted NADPH and glutathione, which exacerbated oxidative stress and correlated with elevated liver inflammation. Thus, despite catalyzing the synthesis of intermediates also produced by other anaplerotic pathways, PC is specifically necessary for maintaining oxidation, biosynthesis, and pathways distal to the TCA cycle, such as antioxidant defenses.
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Affiliation(s)
- David A Cappel
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Stanisław Deja
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - João A G Duarte
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Blanka Kucejova
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Melissa Iñigo
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Justin A Fletcher
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiaorong Fu
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Eric D Berglund
- Center for Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, USA; Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Tiemin Liu
- Sate Key Laboratory of Genetic Engineering, School of Life Sciences, Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, Shanghai 200438, China
| | - Joel K Elmquist
- Center for Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Suntrea Hammer
- Department of Pathology, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Prashant Mishra
- Children's Medical Center Research Institute, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey D Browning
- Department of Clinical Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Shawn C Burgess
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, TX, USA.
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40
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Daurio NA, Wang Y, Chen Y, Zhou H, Carballo-Jane E, Mane J, Rodriguez CG, Zafian P, Houghton A, Addona G, McLaren DG, Zhang R, Shyong BJ, Bateman K, Downes DP, Webb M, Kelley DE, Previs SF. Spatial and temporal studies of metabolic activity: contrasting biochemical kinetics in tissues and pathways during fasted and fed states. Am J Physiol Endocrinol Metab 2019; 316:E1105-E1117. [PMID: 30912961 DOI: 10.1152/ajpendo.00459.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The regulation of nutrient homeostasis, i.e., the ability to transition between fasted and fed states, is fundamental in maintaining health. Since food is typically consumed over limited (anabolic) periods, dietary components must be processed and stored to counterbalance the catabolic stress that occurs between meals. Herein, we contrast tissue- and pathway-specific metabolic activity in fasted and fed states. We demonstrate that knowledge of biochemical kinetics that is obtained from opposite ends of the energetic spectrum can allow mechanism-based differentiation of healthy and disease phenotypes. Rat models of type 1 and type 2 diabetes serve as case studies for probing spatial and temporal patterns of metabolic activity via [2H]water labeling. Experimental designs that capture integrative whole body metabolism, including meal-induced substrate partitioning, can support an array of research surrounding metabolic disease; the relative simplicity of the approach that is discussed here should enable routine applications in preclinical models.
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Affiliation(s)
- Natalie A Daurio
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Yichen Wang
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Ying Chen
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Haihong Zhou
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Ester Carballo-Jane
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Joel Mane
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Carlos G Rodriguez
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Peter Zafian
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Andrea Houghton
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - George Addona
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - David G McLaren
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Rena Zhang
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Bao Jen Shyong
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Kevin Bateman
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Daniel P Downes
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Maria Webb
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - David E Kelley
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Stephen F Previs
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
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Trefts E, Hughey CC, Lantier L, Lark DS, Boyd KL, Pozzi A, Zent R, Wasserman DH. Energy metabolism couples hepatocyte integrin-linked kinase to liver glucoregulation and postabsorptive responses of mice in an age-dependent manner. Am J Physiol Endocrinol Metab 2019; 316:E1118-E1135. [PMID: 30835508 PMCID: PMC6732653 DOI: 10.1152/ajpendo.00496.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Integrin-linked kinase (ILK) is a critical intracellular signaling node for integrin receptors. Its role in liver development is complex, as ILK deletion at E10.5 (before hepatocyte differentiation) results in biochemical and morphological differences that resolve as mice age. Nevertheless, mice with ILK depleted specifically in hepatocytes are protected from the hepatic insulin resistance during obesity. Despite the potential importance of hepatocyte ILK to metabolic health, it is unknown how ILK controls hepatic metabolism or glucoregulation. The present study tested the role of ILK in hepatic metabolism and glucoregulation by deleting it specifically in hepatocytes, using a cre-lox system that begins expression at E15.5 (after initiation of hepatocyte differentiation). These mice develop the most severe morphological and glucoregulatory abnormalities at 6 wk, but these gradually resolve with age. After identifying when the deletion of ILK caused a severe metabolic phenotype, in depth studies were performed at this time point to define the metabolic programs that coordinate control of glucoregulation that are regulated by ILK. We show that 6-wk-old ILK-deficient mice have higher glucose tolerance and decreased net glycogen synthesis. Additionally, ILK was shown to be necessary for transcription of mitochondrial-related genes, oxidative metabolism, and maintenance of cellular energy status. Thus, ILK is required for maintaining hepatic transcriptional and metabolic programs that sustain oxidative metabolism, which are required for hepatic maintenance of glucose homeostasis.
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Affiliation(s)
- Elijah Trefts
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Curtis C Hughey
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Louise Lantier
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
- Mouse Metabolic Phenotyping Center, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Dan S Lark
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Kelli L Boyd
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Ambra Pozzi
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
- Department of Medicine, Vanderbilt University School of Medicine , Nashville, Tennessee
- Veterans Affairs Medical Center , Nashville, Tennessee
| | - Roy Zent
- Department of Medicine, Vanderbilt University School of Medicine , Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine , Nashville, Tennessee
- Veterans Affairs Medical Center , Nashville, Tennessee
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
- Mouse Metabolic Phenotyping Center, Vanderbilt University School of Medicine , Nashville, Tennessee
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42
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Syring KE, Cyphert TJ, Beck TC, Flynn CR, Mignemi NA, McGuinness OP. Systemic bile acids induce insulin resistance in a TGR5-independent manner. Am J Physiol Endocrinol Metab 2019; 316:E782-E793. [PMID: 30779633 PMCID: PMC6732652 DOI: 10.1152/ajpendo.00362.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 02/04/2019] [Accepted: 02/18/2019] [Indexed: 02/07/2023]
Abstract
Bile acids are involved in the emulsification and absorption of dietary fats, as well as acting as signaling molecules. Recently, bile acid signaling through farnesoid X receptor and G protein-coupled bile acid receptor (TGR5) has been reported to elicit changes in not only bile acid synthesis but also metabolic processes, including the alteration of gluconeogenic gene expression and energy expenditure. A role for bile acids in glucose metabolism is also supported by a correlation between changes in the metabolic state of patients (i.e., obesity or postbariatric surgery) and altered serum bile acid levels. However, despite evidence for a role for bile acids during metabolically challenging settings, the direct effect of elevated bile acids on insulin action in the absence of metabolic disease has yet to be investigated. The present study examines the impact of acutely elevated plasma bile acid levels on insulin sensitivity using hyperinsulinemic-euglycemic clamps. In wild-type mice, elevated bile acids impair hepatic insulin sensitivity by blunting the insulin suppression of hepatic glucose production. The impaired hepatic insulin sensitivity could not be attributed to TGR5 signaling, as TGR5 knockout mice exhibited a similar inhibition of insulin suppression of hepatic glucose production. Canonical insulin signaling pathways, such as hepatic PKB (or Akt) activation, were not perturbed in these animals. Interestingly, bile acid infusion directly into the portal vein did not result in an impairment in hepatic insulin sensitivity. Overall, the data indicate that acute increases in circulating bile acids in lean mice impair hepatic insulin sensitivity via an indirect mechanism.
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Affiliation(s)
- Kristen E Syring
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Travis J Cyphert
- Department of Biological Sciences, Marshall University College of Science, Huntington, West Virginia
| | - Thomas C Beck
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Nicholas A Mignemi
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Owen P McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
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43
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Vinnakota KC, Pannala VR, Wall ML, Rahim M, Estes SK, Trenary I, O'Brien TP, Printz RL, Reifman J, Shiota M, Young JD, Wallqvist A. Network Modeling of Liver Metabolism to Predict Plasma Metabolite Changes During Short-Term Fasting in the Laboratory Rat. Front Physiol 2019; 10:161. [PMID: 30881311 PMCID: PMC6405515 DOI: 10.3389/fphys.2019.00161] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 02/11/2019] [Indexed: 12/20/2022] Open
Abstract
The liver—a central metabolic organ that integrates whole-body metabolism to maintain glucose and fatty-acid regulation, and detoxify ammonia—is susceptible to injuries induced by drugs and toxic substances. Although plasma metabolite profiles are increasingly investigated for their potential to detect liver injury earlier than current clinical markers, their utility may be compromised because such profiles are affected by the nutritional state and the physiological state of the animal, and by contributions from extrahepatic sources. To tease apart the contributions of liver and non-liver sources to alterations in plasma metabolite profiles, here we sought to computationally isolate the plasma metabolite changes originating in the liver during short-term fasting. We used a constraint-based metabolic modeling approach to integrate central carbon fluxes measured in our study, and physiological flux boundary conditions gathered from the literature, into a genome-scale model of rat liver metabolism. We then measured plasma metabolite profiles in rats fasted for 5–7 or 10–13 h to test our model predictions. Our computational model accounted for two-thirds of the observed directions of change (an increase or decrease) in plasma metabolites, indicating their origin in the liver. Specifically, our work suggests that changes in plasma lipid metabolites, which are reliably predicted by our liver metabolism model, are key features of short-term fasting. Our approach provides a mechanistic model for identifying plasma metabolite changes originating in the liver.
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Affiliation(s)
- Kalyan C Vinnakota
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States.,Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, United States
| | - Venkat R Pannala
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States.,Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, United States
| | - Martha L Wall
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN, United States
| | - Mohsin Rahim
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN, United States
| | - Shanea K Estes
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Irina Trenary
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN, United States
| | - Tracy P O'Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Richard L Printz
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, United States
| | - Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN, United States.,Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, United States
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44
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Hughey CC, James FD, Wang Z, Goelzer M, Wasserman DH. Dysregulated transmethylation leading to hepatocellular carcinoma compromises redox homeostasis and glucose formation. Mol Metab 2019; 23:1-13. [PMID: 30850319 PMCID: PMC6479583 DOI: 10.1016/j.molmet.2019.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 02/18/2019] [Accepted: 02/20/2019] [Indexed: 12/24/2022] Open
Abstract
Objective The loss of liver glycine N-methyltransferase (GNMT) promotes liver steatosis and the transition to hepatocellular carcinoma (HCC). Previous work showed endogenous glucose production is reduced in GNMT-null mice with gluconeogenic precursors being used in alternative biosynthetic pathways that utilize methyl donors and are linked to tumorigenesis. This metabolic programming occurs before the appearance of HCC in GNMT-null mice. The metabolic physiology that sustains liver tumor formation in GNMT-null mice is unknown. The studies presented here tested the hypothesis that nutrient flux pivots from glucose production to pathways that incorporate and metabolize methyl groups in GNMT-null mice with HCC. Methods 2H/13C metabolic flux analysis was performed in conscious, unrestrained mice lacking GNMT to quantify glucose formation and associated nutrient fluxes. Molecular analyses of livers from mice lacking GNMT including metabolomic, immunoblotting, and immunochemistry were completed to fully interpret the nutrient fluxes. Results GNMT knockout (KO) mice showed lower blood glucose that was accompanied by a reduction in liver glycogenolysis and gluconeogenesis. NAD+ was lower and the NAD(P)H-to-NAD(P)+ ratio was higher in livers of KO mice. Indices of NAD+ synthesis and catabolism, pentose phosphate pathway flux, and glutathione synthesis were dysregulated in KO mice. Conclusion Glucose precursor flux away from glucose formation towards pathways that regulate redox status increase in the liver. Moreover, synthesis and scavenging of NAD+ are both impaired resulting in reduced concentrations. This metabolic program blunts an increase in methyl donor availability, however, biosynthetic pathways underlying HCC are activated. Loss of glycine N-methyltransferase results in hepatocellular carcinoma. Metabolic reprogramming ensues to attenuate the increased S-adenosylmethionine. The metabolic changes include dysregulated liver NAD+ homeostasis and redox state. Liver glucose formation is reduced and precursors directed to biosynthetic pathways.
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Affiliation(s)
- Curtis C Hughey
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, USA.
| | - Freyja D James
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, USA; Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN, USA
| | - Zhizhang Wang
- Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN, USA
| | - Mickael Goelzer
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, USA
| | - David H Wasserman
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, USA; Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN, USA
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45
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Hunter RW, Hughey CC, Lantier L, Sundelin EI, Peggie M, Zeqiraj E, Sicheri F, Jessen N, Wasserman DH, Sakamoto K. Metformin reduces liver glucose production by inhibition of fructose-1-6-bisphosphatase. Nat Med 2018; 24:1395-1406. [PMID: 30150719 PMCID: PMC6207338 DOI: 10.1038/s41591-018-0159-7] [Citation(s) in RCA: 187] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 07/24/2018] [Indexed: 01/03/2023]
Abstract
Metformin is a first-line drug for the treatment of individuals with type 2 diabetes, yet its precise mechanism of action remains unclear. Metformin exerts its antihyperglycemic action primarily through lowering hepatic glucose production (HGP). This suppression is thought to be mediated through inhibition of mitochondrial respiratory complex I, and thus elevation of 5'-adenosine monophosphate (AMP) levels and the activation of AMP-activated protein kinase (AMPK), though this proposition has been challenged given results in mice lacking hepatic AMPK. Here we report that the AMP-inhibited enzyme fructose-1,6-bisphosphatase-1 (FBP1), a rate-controlling enzyme in gluconeogenesis, functions as a major contributor to the therapeutic action of metformin. We identified a point mutation in FBP1 that renders it insensitive to AMP while sparing regulation by fructose-2,6-bisphosphate (F-2,6-P2), and knock-in (KI) of this mutant in mice significantly reduces their response to metformin treatment. We observe this during a metformin tolerance test and in a metformin-euglycemic clamp that we have developed. The antihyperglycemic effect of metformin in high-fat diet-fed diabetic FBP1-KI mice was also significantly blunted compared to wild-type controls. Collectively, we show a new mechanism of action for metformin and provide further evidence that molecular targeting of FBP1 can have antihyperglycemic effects.
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Affiliation(s)
- Roger W Hunter
- Nestlé Institute of Health Sciences SA, Lausanne, Switzerland
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK
| | - Curtis C Hughey
- Department of Molecular Physiology and Biophysics and the Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN, USA
| | - Louise Lantier
- Department of Molecular Physiology and Biophysics and the Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN, USA
| | - Elias I Sundelin
- Departments of Clinical Medicine and Biomedicine, Aarhus University, Aarhus, Denmark
| | - Mark Peggie
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee, UK
| | - Elton Zeqiraj
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Frank Sicheri
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
- Departments of Biochemistry and Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Niels Jessen
- Departments of Clinical Medicine and Biomedicine, Aarhus University, Aarhus, Denmark
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics and the Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN, USA
| | - Kei Sakamoto
- Nestlé Institute of Health Sciences SA, Lausanne, Switzerland.
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46
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Pannala VR, Wall ML, Estes SK, Trenary I, O'Brien TP, Printz RL, Vinnakota KC, Reifman J, Shiota M, Young JD, Wallqvist A. Metabolic network-based predictions of toxicant-induced metabolite changes in the laboratory rat. Sci Rep 2018; 8:11678. [PMID: 30076366 PMCID: PMC6076258 DOI: 10.1038/s41598-018-30149-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 07/23/2018] [Indexed: 12/11/2022] Open
Abstract
In order to provide timely treatment for organ damage initiated by therapeutic drugs or exposure to environmental toxicants, we first need to identify markers that provide an early diagnosis of potential adverse effects before permanent damage occurs. Specifically, the liver, as a primary organ prone to toxicants-induced injuries, lacks diagnostic markers that are specific and sensitive to the early onset of injury. Here, to identify plasma metabolites as markers of early toxicant-induced injury, we used a constraint-based modeling approach with a genome-scale network reconstruction of rat liver metabolism to incorporate perturbations of gene expression induced by acetaminophen, a known hepatotoxicant. A comparison of the model results against the global metabolic profiling data revealed that our approach satisfactorily predicted altered plasma metabolite levels as early as 5 h after exposure to 2 g/kg of acetaminophen, and that 10 h after treatment the predictions significantly improved when we integrated measured central carbon fluxes. Our approach is solely driven by gene expression and physiological boundary conditions, and does not rely on any toxicant-specific model component. As such, it provides a mechanistic model that serves as a first step in identifying a list of putative plasma metabolites that could change due to toxicant-induced perturbations.
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Affiliation(s)
- Venkat R Pannala
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD, 21702, USA.
| | - Martha L Wall
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN, 37232, USA
| | - Shanea K Estes
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Irina Trenary
- Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN, 37232, USA
| | - Tracy P O'Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Richard L Printz
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Kalyan C Vinnakota
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD, 21702, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD, 21702, USA
| | - Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Jamey D Young
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA. .,Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN, 37232, USA.
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD, 21702, USA.
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47
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d'Avignon DA, Puchalska P, Ercal B, Chang Y, Martin SE, Graham MJ, Patti GJ, Han X, Crawford PA. Hepatic ketogenic insufficiency reprograms hepatic glycogen metabolism and the lipidome. JCI Insight 2018; 3:99762. [PMID: 29925686 DOI: 10.1172/jci.insight.99762] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 05/17/2018] [Indexed: 02/06/2023] Open
Abstract
While several molecular targets are under consideration, mechanistic underpinnings of the transition from uncomplicated nonalcoholic fatty liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH) remain unresolved. Here we apply multiscale chemical profiling technologies to mouse models of deranged hepatic ketogenesis to uncover potential NAFLD driver signatures. Use of stable-isotope tracers, quantitatively tracked by nuclear magnetic resonance (NMR) spectroscopy, supported previous observations that livers of wild-type mice maintained long term on a high-fat diet (HFD) exhibit a marked increase in hepatic energy charge. Fed-state ketogenesis rates increased nearly 3-fold in livers of HFD-fed mice, a greater proportionate increase than that observed for tricarboxylic acid (TCA) cycle flux, but both of these contributors to overall hepatic energy homeostasis fueled markedly increased hepatic glucose production (HGP). Thus, to selectively determine the role of the ketogenic conduit on HGP and oxidative hepatic fluxes, we studied a ketogenesis-insufficient mouse model generated by knockdown of the mitochondrial isoform of 3-hydroxymethylglutaryl-CoA synthase (HMGCS2). In response to ketogenic insufficiency, TCA cycle flux in the fed state doubled and HGP increased more than 60%, sourced by a 3-fold increase in glycogenolysis. Finally, high-resolution untargeted metabolomics and shotgun lipidomics performed using ketogenesis-insufficient livers in the fed state revealed accumulation of bis(monoacylglycero)phosphates, which also accumulated in livers of other models commonly used to study NAFLD. In summary, natural and interventional variations in ketogenesis in the fed state strongly influence hepatic energy homeostasis, glucose metabolism, and the lipidome. Importantly, HGP remains tightly linked to overall hepatic energy charge, which includes both terminal fat oxidation through the TCA cycle and partial oxidation via ketogenesis.
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Affiliation(s)
- D André d'Avignon
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.,Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA
| | - Patrycja Puchalska
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.,Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA
| | - Baris Ercal
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA.,Department of Psychiatry, Washington University, St. Louis, Missouri, USA
| | - YingJu Chang
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.,Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA
| | - Shannon E Martin
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA.,Pathobiology Graduate Program, Brown University, Providence, Rhode Island, USA
| | | | - Gary J Patti
- Department of Chemistry, Washington University, St. Louis, Missouri, USA
| | - Xianlin Han
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA.,Barshop Institute for Longevity and Aging Studies, Department of Medicine, Division of Diabetes, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Peter A Crawford
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.,Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA.,Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
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48
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Hughey CC, Trefts E, Bracy DP, James FD, Donahue EP, Wasserman DH. Glycine N-methyltransferase deletion in mice diverts carbon flux from gluconeogenesis to pathways that utilize excess methionine cycle intermediates. J Biol Chem 2018; 293:11944-11954. [PMID: 29891549 DOI: 10.1074/jbc.ra118.002568] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 05/17/2018] [Indexed: 12/19/2022] Open
Abstract
Glycine N-methyltransferase (GNMT) is the most abundant liver methyltransferase regulating the availability of the biological methyl donor, S-adenosylmethionine (SAM). Moreover, GNMT has been identified to be down-regulated in hepatocellular carcinoma (HCC). Despite its role in regulating SAM levels and association of its down-regulation with liver tumorigenesis, the impact of reduced GNMT on metabolic reprogramming before the manifestation of HCC has not been investigated in detail. Herein, we used 2H/13C metabolic flux analysis in conscious, unrestrained mice to test the hypothesis that the absence of GNMT causes metabolic reprogramming. GNMT-null (KO) mice displayed a reduction in blood glucose that was associated with a decline in both hepatic glycogenolysis and gluconeogenesis. The reduced gluconeogenesis was due to a decrease in liver gluconeogenic precursors, citric acid cycle fluxes, and anaplerosis and cataplerosis. A concurrent elevation in both hepatic SAM and metabolites of SAM utilization pathways was observed in the KO mice. Specifically, the increase in metabolites of SAM utilization pathways indicated that hepatic polyamine synthesis and catabolism, transsulfuration, and de novo lipogenesis pathways were increased in the KO mice. Of note, these pathways utilize substrates that could otherwise be used for gluconeogenesis. Also, this metabolic reprogramming occurs before the well-documented appearance of HCC in GNMT-null mice. Together, these results indicate that GNMT deletion promotes a metabolic shift whereby nutrients are channeled away from glucose formation toward pathways that utilize the elevated SAM.
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Affiliation(s)
- Curtis C Hughey
- From the Department of Molecular Physiology and Biophysics and
| | - Elijah Trefts
- From the Department of Molecular Physiology and Biophysics and
| | - Deanna P Bracy
- From the Department of Molecular Physiology and Biophysics and.,the Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, Tennessee 37232
| | - Freyja D James
- From the Department of Molecular Physiology and Biophysics and.,the Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, Tennessee 37232
| | | | - David H Wasserman
- From the Department of Molecular Physiology and Biophysics and.,the Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, Tennessee 37232
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49
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A guide to 13C metabolic flux analysis for the cancer biologist. Exp Mol Med 2018; 50:1-13. [PMID: 29657327 PMCID: PMC5938039 DOI: 10.1038/s12276-018-0060-y] [Citation(s) in RCA: 162] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 12/21/2017] [Indexed: 01/15/2023] Open
Abstract
Cancer metabolism is significantly altered from normal cellular metabolism allowing cancer cells to adapt to changing microenvironments and maintain high rates of proliferation. In the past decade, stable-isotope tracing and network analysis have become powerful tools for uncovering metabolic pathways that are differentially activated in cancer cells. In particular, 13C metabolic flux analysis (13C-MFA) has emerged as the primary technique for quantifying intracellular fluxes in cancer cells. In this review, we provide a practical guide for investigators interested in getting started with 13C-MFA. We describe best practices in 13C-MFA, highlight potential pitfalls and alternative approaches, and conclude with new developments that can further enhance our understanding of cancer metabolism. Tracing tagged molecules can help researchers understand the altered metabolism of cancer cells. The abilities of cancer cells to multiply rapidly and invade new tissues are supported by metabolic alterations, which can be investigated by feeding tagged molecules to cells and tracing how they are metabolized. These techniques, such as 13C metabolic flux analysis (13C-MFA), have been perceived as difficult to use, but recent advances are making them more accessible. Maciek Antoniewicz, University of Delaware, Newark, USA, has published a practical guide for researchers wanting to use 13C-MFA. The review includes best practices, pitfalls, alternative approaches, and new developments, especially new user-friendly software that allows researchers without extensive training in mathematics, statistics, or coding to perform 13C-MFA. Broadening access to tools for investigating altered metabolic pathways may spur development of new cancer therapies targeting these pathways.
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50
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Rossi M, Zhu L, McMillin SM, Pydi SP, Jain S, Wang L, Cui Y, Lee RJ, Cohen AH, Kaneto H, Birnbaum MJ, Ma Y, Rotman Y, Liu J, Cyphert TJ, Finkel T, McGuinness OP, Wess J. Hepatic Gi signaling regulates whole-body glucose homeostasis. J Clin Invest 2018; 128:746-759. [PMID: 29337301 PMCID: PMC5785257 DOI: 10.1172/jci94505] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 11/17/2017] [Indexed: 01/12/2023] Open
Abstract
An increase in hepatic glucose production (HGP) is a key feature of type 2 diabetes. Excessive signaling through hepatic Gs-linked glucagon receptors critically contributes to pathologically elevated HGP. Here, we tested the hypothesis that this metabolic impairment can be counteracted by enhancing hepatic Gi signaling. Specifically, we used a chemogenetic approach to selectively activate Gi-type G proteins in mouse hepatocytes in vivo. Unexpectedly, activation of hepatic Gi signaling triggered a pronounced increase in HGP and severely impaired glucose homeostasis. Moreover, increased Gi signaling stimulated glucose release in human hepatocytes. A lack of functional Gi-type G proteins in hepatocytes reduced blood glucose levels and protected mice against the metabolic deficits caused by the consumption of a high-fat diet. Additionally, we delineated a signaling cascade that links hepatic Gi signaling to ROS production, JNK activation, and a subsequent increase in HGP. Taken together, our data support the concept that drugs able to block hepatic Gi-coupled GPCRs may prove beneficial as antidiabetic drugs.
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Affiliation(s)
- Mario Rossi
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Lu Zhu
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Sara M. McMillin
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Sai Prasad Pydi
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Shanu Jain
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Lei Wang
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Yinghong Cui
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Regina J. Lee
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Amanda H. Cohen
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Hideaki Kaneto
- Osaka University Graduate School of Medicine, Osaka, Japan
| | - Morris J. Birnbaum
- Cardiovascular and Metabolic Diseases (CVMED), Pfizer Inc., Cambridge, Massachusetts, USA
| | - Yanling Ma
- Liver and Energy Metabolism Unit, Liver Diseases Branch, NIDDK, Bethesda, Maryland, USA
| | - Yaron Rotman
- Liver and Energy Metabolism Unit, Liver Diseases Branch, NIDDK, Bethesda, Maryland, USA
| | - Jie Liu
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), Bethesda, Maryland, USA
| | - Travis J. Cyphert
- Departments of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Toren Finkel
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), Bethesda, Maryland, USA
| | - Owen P. McGuinness
- Departments of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
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