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Lane AN, Higashi RM, Fan TWM. Challenges of Spatially Resolved Metabolism in Cancer Research. Metabolites 2024; 14:383. [PMID: 39057706 PMCID: PMC11278851 DOI: 10.3390/metabo14070383] [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: 05/26/2024] [Revised: 06/28/2024] [Accepted: 07/07/2024] [Indexed: 07/28/2024] Open
Abstract
Stable isotope-resolved metabolomics comprises a critical set of technologies that can be applied to a wide variety of systems, from isolated cells to whole organisms, to define metabolic pathway usage and responses to perturbations such as drugs or mutations, as well as providing the basis for flux analysis. As the diversity of stable isotope-enriched compounds is very high, and with newer approaches to multiplexing, the coverage of metabolism is now very extensive. However, as the complexity of the model increases, including more kinds of interacting cell types and interorgan communication, the analytical complexity also increases. Further, as studies move further into spatially resolved biology, new technical problems have to be overcome owing to the small number of analytes present in the confines of a single cell or cell compartment. Here, we review the overall goals and solutions made possible by stable isotope tracing and their applications to models of increasing complexity. Finally, we discuss progress and outstanding difficulties in high-resolution spatially resolved tracer-based metabolic studies.
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Affiliation(s)
- Andrew N. Lane
- Department of Toxicology and Cancer Biology and Markey Cancer Center, University of Kentucky, 789 S. Limestone St., Lexington, KY 40536, USA; (R.M.H.); (T.W.-M.F.)
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2
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Jang J, Kim Y, Song T, Park S, Kim HJ, Koh JH, Cho Y, Park SY, Sadayappan S, Kwak HB, Wolfe RR, Kim IY, Choi CS. Free essential amino acid feeding improves endurance during resistance training via DRP1-dependent mitochondrial remodelling. J Cachexia Sarcopenia Muscle 2024. [PMID: 38881251 DOI: 10.1002/jcsm.13519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 05/15/2024] [Accepted: 05/16/2024] [Indexed: 06/18/2024] Open
Abstract
BACKGROUND Loss of muscle strength and endurance with aging or in various conditions negatively affects quality of life. Resistance exercise training (RET) is the most powerful means to improve muscle mass and strength, but it does not generally lead to improvements in endurance capacity. Free essential amino acids (EAAs) act as precursors and stimuli for synthesis of both mitochondrial and myofibrillar proteins that could potentially confer endurance and strength gains. Thus, we hypothesized that daily consumption of a dietary supplement of nine free EAAs with RET improves endurance in addition to the strength gains by RET. METHODS Male C57BL6J mice (9 weeks old) were assigned to control (CON), EAA, RET (ladder climbing, 3 times a week), or combined treatment of EAA and RET (EAA + RET) groups. Physical functions focusing on strength or endurance were assessed before and after the interventions. Several analyses were performed to gain better insight into the mechanisms by which muscle function was improved. We determined cumulative rates of myofibrillar and mitochondrial protein synthesis using 2H2O labelling and mass spectrometry; assessed ex vivo contractile properties and in vitro mitochondrial function, evaluated neuromuscular junction (NMJ) stability, and assessed implicated molecular singling pathways. Furthermore, whole-body and muscle insulin sensitivity along with glucose metabolism, were evaluated using a hyperinsulinaemic-euglycaemic clamp. RESULTS EAA + RET increased muscle mass (10%, P < 0.05) and strength (6%, P < 0.05) more than RET alone, due to an enhanced rate of integrated muscle protein synthesis (19%, P < 0.05) with concomitant activation of Akt1/mTORC1 signalling. Muscle quality (muscle strength normalized to mass) was improved by RET (i.e., RET and EAA + RET) compared with sedentary groups (10%, P < 0.05), which was associated with increased AchR cluster size and MuSK activation (P < 0.05). EAA + RET also increased endurance capacity more than RET alone (26%, P < 0.05) by increasing both mitochondrial protein synthesis (53%, P < 0.05) and DRP1 activation (P < 0.05). Maximal respiratory capacity increased (P < 0.05) through activation of the mTORC1-DRP1 signalling axis. These favourable effects were accompanied by an improvement in basal glucose metabolism (i.e., blood glucose concentrations and endogenous glucose production vs. CON, P < 0.05). CONCLUSIONS Combined treatment with balanced free EAAs and RET may effectively promote endurance capacity as well as muscle strength through increased muscle protein synthesis, improved NMJ stability, and enhanced mitochondrial dynamics via mTORC1-DRP1 axis activation, ultimately leading to improved basal glucose metabolism.
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Affiliation(s)
- Jiwoong Jang
- Integrative Metabolic Fluxomics Lab, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Department of Internal Medicine, Gil Medical Center, Gachon University, Incheon, Korea
| | - Yeongmin Kim
- Integrative Metabolic Fluxomics Lab, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, Korea
| | - Taejeong Song
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, Center for Cardiovascular Research, University of Cincinnati, Cincinnati, Ohio, USA
| | - Sanghee Park
- Integrative Metabolic Fluxomics Lab, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon, Korea
| | - Hee-Joo Kim
- Integrative Metabolic Fluxomics Lab, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, Korea
| | - Jin-Ho Koh
- Integrative Metabolic Fluxomics Lab, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon, Korea
| | - Yoonil Cho
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, Korea
| | - Shi-Young Park
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Gachon Biomedical Convergence Institute, Gachon University Gil Medical Center, Incheon, Korea
| | - Sakthivel Sadayappan
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, Center for Cardiovascular Research, University of Cincinnati, Cincinnati, Ohio, USA
| | - Hyo-Bum Kwak
- Department of Kinesiology, Inha University, Incheon, Korea
- Institute of Sports & Arts Convergence, Inha University, Incheon, Korea
- Department of Biomedical Science, Program in Biomedical Science & Engineering, Inha University, Incheon, Korea
| | - Robert R Wolfe
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Il-Young Kim
- Integrative Metabolic Fluxomics Lab, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon, Korea
| | - Cheol Soo Choi
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- Department of Internal Medicine, Gil Medical Center, Gachon University, Incheon, Korea
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon, Korea
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3
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Petersen MC, Smith GI, Palacios HH, Farabi SS, Yoshino M, Yoshino J, Cho K, Davila-Roman VG, Shankaran M, Barve RA, Yu J, Stern JH, Patterson BW, Hellerstein MK, Shulman GI, Patti GJ, Klein S. Cardiometabolic characteristics of people with metabolically healthy and unhealthy obesity. Cell Metab 2024; 36:745-761.e5. [PMID: 38569471 PMCID: PMC11025492 DOI: 10.1016/j.cmet.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/06/2024] [Accepted: 03/06/2024] [Indexed: 04/05/2024]
Abstract
There is considerable heterogeneity in the cardiometabolic abnormalities associated with obesity. We evaluated multi-organ system metabolic function in 20 adults with metabolically healthy obesity (MHO; normal fasting glucose and triglycerides, oral glucose tolerance, intrahepatic triglyceride content, and whole-body insulin sensitivity), 20 adults with metabolically unhealthy obesity (MUO; prediabetes, hepatic steatosis, and whole-body insulin resistance), and 15 adults who were metabolically healthy lean. Compared with MUO, people with MHO had (1) altered skeletal muscle biology (decreased ceramide content and increased expression of genes involved in BCAA catabolism and mitochondrial structure/function); (2) altered adipose tissue biology (decreased expression of genes involved in inflammation and extracellular matrix remodeling and increased expression of genes involved in lipogenesis); (3) lower 24-h plasma glucose, insulin, non-esterified fatty acids, and triglycerides; (4) higher plasma adiponectin and lower plasma PAI-1 concentrations; and (5) decreased oxidative stress. These findings provide a framework of potential mechanisms responsible for MHO and the metabolic heterogeneity of obesity. This study was registered at ClinicalTrials.gov (NCT02706262).
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Affiliation(s)
- Max C Petersen
- Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO, USA; Division of Endocrinology, Metabolism, and Lipid Research, Washington University in St. Louis, St. Louis, MO, USA
| | - Gordon I Smith
- Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO, USA
| | - Hector H Palacios
- Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO, USA
| | - Sarah S Farabi
- Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO, USA; Goldfarb School of Nursing at Barnes-Jewish College, St. Louis, MO, USA
| | - Mihoko Yoshino
- Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO, USA
| | - Jun Yoshino
- Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO, USA; Division of Nephrology, Endocrinology and Metabolism, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Kevin Cho
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Victor G Davila-Roman
- Cardiovascular Imaging and Clinical Research Core Laboratory, Cardiovascular Division, Washington University in St. Louis, St. Louis, MO, USA
| | | | - Ruteja A Barve
- Department of Genetics, Washington University in St. Louis, St. Louis, MO, USA
| | - Jinsheng Yu
- Department of Genetics, Washington University in St. Louis, St. Louis, MO, USA
| | - Jennifer H Stern
- Division of Endocrinology, Department of Medicine, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Bruce W Patterson
- Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO, USA
| | | | - Gerald I Shulman
- Departments of Internal Medicine and Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT, USA
| | - Gary J Patti
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Samuel Klein
- Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO, USA.
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Slusher AL, Nouws J, Tokoglu F, Vash-Margita A, Matthews MD, Fitch M, Shankaran M, Hellerstein MK, Caprio S. Altered extracellular matrix dynamics is associated with insulin resistance in adolescent children with obesity. Obesity (Silver Spring) 2024; 32:593-602. [PMID: 38410080 PMCID: PMC11034857 DOI: 10.1002/oby.23974] [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: 10/11/2023] [Revised: 11/27/2023] [Accepted: 11/29/2023] [Indexed: 02/28/2024]
Abstract
OBJECTIVE The objective of this study was to examine the hypothesis that abdominal and gluteal adipocyte turnover, lipid dynamics, and fibrogenesis are dysregulated among insulin-resistant (IR) compared with insulin-sensitive (IS) adolescents with obesity. METHODS Seven IS and seven IR adolescents with obesity participated in a 3-h oral glucose tolerance test and a multi-section magnetic resonance imaging scan of the abdominal region to examine body fat distribution patterns and liver fat content. An 8-week 70% deuterated water (2 H2 O) labeling protocol examined adipocyte turnover, lipid dynamics, and fibrogenesis in vivo from biopsied abdominal and gluteal fat. RESULTS Abdominal and gluteal subcutaneous adipose tissue (SAT) turnover rates of lipid components were similar among IS and IR adolescents with obesity. However, the insoluble collagen (type I, subunit α2) isoform measured from abdominal, but not gluteal, SAT was elevated in IR compared with IS individuals. In addition, abdominal insoluble collagen Iα2 was associated with ratios of visceral-to-total (visceral adipose tissue + SAT) abdominal fat and whole-body and adipose tissue insulin signaling, and it trended toward a positive association with liver fat content. CONCLUSIONS Altered extracellular matrix dynamics, but not expandability, potentially decreases abdominal SAT lipid storage capacity, contributing to the pathophysiological pathways linking adipose tissue and whole-body IR with altered ectopic storage of lipids within the liver among IR adolescents with obesity.
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Affiliation(s)
- Aaron L. Slusher
- Department of Pediatrics, Yale School of Medicine, New Haven, CT, USA
| | - Jessica Nouws
- Pulmonary, Critical Care and Sleep Medicine, Yale School of Medicine, New Haven, CT
| | - Fuyuze Tokoglu
- Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Alla Vash-Margita
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA
| | - Marcy D. Matthews
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, CA, USA
| | - Mark Fitch
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, CA, USA
| | - Mahalakshmi Shankaran
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, CA, USA
| | - Marc K. Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, CA, USA
| | - Sonia Caprio
- Department of Pediatrics, Yale School of Medicine, New Haven, CT, USA
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Gugliucci A. The chylomicron saga: time to focus on postprandial metabolism. Front Endocrinol (Lausanne) 2024; 14:1322869. [PMID: 38303975 PMCID: PMC10830840 DOI: 10.3389/fendo.2023.1322869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/28/2023] [Indexed: 02/03/2024] Open
Abstract
Since statins have had such tremendous therapeutic success over the last three decades, the field of atherosclerosis has become somewhat LDL-centric, dismissing the relevance of triglycerides (TG), particularly chylomicrons, in atherogenesis. Nonetheless, 50% of patients who take statins are at risk of developing atherosclerotic cardiovascular disease (ASCVD) and are unable to achieve their goal LDL-C levels. This residual risk is mediated, in part by triglyceride rich lipoproteins (TRL) and their remnants. Following his seminal investigation on the subject, Zilversmit proposed that atherosclerosis is a postprandial event in 1979 (1-4). In essence, the concept suggests that remnant cholesterol-rich chylomicron (CM) and very-low density lipoprotein (VLDL) particles play a role in atherogenesis. Given the foregoing, this narrative review addresses the most recent improvements in our understanding of postprandial dyslipidemia. The primary metabolic pathways of chylomicrons are discussed, emphasizing the critical physiological role of lipoprotein lipase and apoCIII, the importance of these particles' fluxes in the postprandial period, their catabolic rate, the complexities of testing postprandial metabolism, and the role of angiopoietin-like proteins in the partition of CM during the fed cycle. The narrative is rounded out by the dysregulation of postprandial lipid metabolism in insulin resistance states and consequent CVD risk, the clinical evaluation of postprandial dyslipidemia, current research limits, and potential future study directions.
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Affiliation(s)
- Alejandro Gugliucci
- Glycation, Oxidation and Disease Laboratory, Department of Research, Touro University California, Vallejo, CA, United States
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Dawson MA, Hennigar SR, Shankaran M, Kelley AM, Anderson BJ, Nyangau E, Field TJ, Evans WJ, Hellerstein MK, McClung JP, Pasiakos SM, Berryman CE. Replacement of dietary carbohydrate with protein increases fat mass and reduces hepatic triglyceride synthesis and content in female obese Zucker rats. Physiol Rep 2023; 11:e15885. [PMID: 38036455 PMCID: PMC10689297 DOI: 10.14814/phy2.15885] [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: 11/03/2023] [Revised: 11/15/2023] [Accepted: 11/15/2023] [Indexed: 12/02/2023] Open
Abstract
Previous studies have demonstrated both energy restriction (ER) and higher protein (HP), lower carbohydrate (LC) diets downregulate hepatic de novo lipogenesis. Little is known about the independent and combined impact of ER and HP/LC diets on tissue-specific lipid kinetics in leptin receptor-deficient, obese rodents. This study investigated the effects of ER and dietary macronutrient content on body composition; hepatic, subcutaneous adipose tissue (SAT), and visceral AT (VAT) lipid metabolic flux (2 H2 O-labeling); and blood and liver measures of cardiometabolic health in six-week-old female obese Zucker rats (Leprfa+/fa+ ). Animals were randomized to a 10-week feeding intervention: ad libitum (AL)-HC/LP (76% carbohydrate/15% protein), AL-HP/LC (35% protein/56% carbohydrate), ER-HC/LP, or ER-HP/LC. ER groups consumed 60% of the feed consumed by AL. AL gained more fat mass than ER (P-energy = 0.012) and HP/LC gained more fat mass than HC/LP (P-diet = 0.025). Hepatic triglyceride (TG) concentrations (P-interaction = 0.0091) and absolute hepatic TG synthesis (P-interaction = 0.012) were lower in ER-HP/LC versus ER-HC/LP. ER had increased hepatic, SAT, and VAT de novo cholesterol fractional synthesis, absolute hepatic cholesterol synthesis, and serum cholesterol (P-energy≤0.0035). A HP/LC diet, independent of energy intake, led to greater gains in fat mass. A HP/LC diet, in the context of ER, led to reductions in absolute hepatic TG synthesis and TG content. However, ER worsened cholesterol metabolism. Increased adipose tissue TG retention with the HP/LC diet may reflect improved lipid storage capacity and be beneficial in this genetic model of obesity.
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Affiliation(s)
- M. Alan Dawson
- Department of Nutrition and Integrative PhysiologyFlorida State UniversityTallahasseeFloridaUSA
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Stephen R. Hennigar
- Department of Nutrition and Integrative PhysiologyFlorida State UniversityTallahasseeFloridaUSA
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
- Oak Ridge Institute for Science and EducationBelcampMarylandUSA
- Pennington Biomedical Research CenterLouisiana State UniversityBaton RougeLouisianaUSA
| | - Mahalakshmi Shankaran
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Alyssa M. Kelley
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
- Oak Ridge Institute for Science and EducationBelcampMarylandUSA
| | - Bradley J. Anderson
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
- Oak Ridge Institute for Science and EducationBelcampMarylandUSA
| | - Edna Nyangau
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Tyler J. Field
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - William J. Evans
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Marc K. Hellerstein
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - James P. McClung
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Stefan M. Pasiakos
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
- Military Performance DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Claire E. Berryman
- Department of Nutrition and Integrative PhysiologyFlorida State UniversityTallahasseeFloridaUSA
- Military Nutrition DivisionUS Army Research Institute of Environmental MedicineNatickMassachusettsUSA
- Oak Ridge Institute for Science and EducationBelcampMarylandUSA
- Pennington Biomedical Research CenterLouisiana State UniversityBaton RougeLouisianaUSA
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Palacios-Marin I, Serra D, Jiménez-Chillarón JC, Herrero L, Todorčević M. Childhood obesity: Implications on adipose tissue dynamics and metabolic health. Obes Rev 2023; 24:e13627. [PMID: 37608466 DOI: 10.1111/obr.13627] [Citation(s) in RCA: 1] [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: 11/11/2022] [Revised: 07/20/2023] [Accepted: 07/23/2023] [Indexed: 08/24/2023]
Abstract
Obesity is the leading risk factor for the development of type 2 diabetes and cardiovascular diseases. Childhood obesity represents an alarming health challenge because children with obesity are prone to remain with obesity throughout their life and have an increased morbidity and mortality risk. The ability of adipose tissue to store lipids and expand in size during excessive calorie intake is its most remarkable characteristic. Cellular and lipid turnovers determine adipose tissue size and are closely related with metabolic status. The mechanisms through which adipose tissue expands and how this affects systemic metabolic homeostasis are still poorly characterized. Furthermore, the mechanism through which increased adiposity extends from childhood to adulthood and its implications in metabolic health are in most part, still unknown. More studies on adipose tissue development in healthy and children with obesity are urgently needed. In the present review, we summarize the dynamics of white adipose tissue, from developmental origins to the mechanisms that allows it to grow and expand throughout lifetime and during obesity in children and in different mouse models used to address this largely unknown field. Specially, highlighting the role that excessive adiposity during the early life has on future's adipose tissue dynamics and individual's health.
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Affiliation(s)
- Ivonne Palacios-Marin
- Endocrinology Department, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona (UB), Barcelona, Spain
| | - Dolors Serra
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona (UB), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Josep C Jiménez-Chillarón
- Endocrinology Department, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Department of Physiological Sciences, School of Medicine, Universitat de Barcelona, L'Hospitalet de Llobregat, Catalonia, Spain
| | - Laura Herrero
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona (UB), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Marijana Todorčević
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona (UB), Barcelona, Spain
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Palacios-Marin I, Serra D, Jimenez-Chillarón J, Herrero L, Todorčević M. Adipose Tissue Dynamics: Cellular and Lipid Turnover in Health and Disease. Nutrients 2023; 15:3968. [PMID: 37764752 PMCID: PMC10535304 DOI: 10.3390/nu15183968] [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: 08/13/2023] [Revised: 08/30/2023] [Accepted: 09/10/2023] [Indexed: 09/29/2023] Open
Abstract
The alarming increase in obesity and its related metabolic health complications, such as type 2 diabetes, has evolved into a global pandemic. Obesity is mainly characterized by excessive accumulation of adipose tissue, primarily due to an imbalance between energy intake and expenditure. Prolonged positive energy balance leads to the expansion of existing adipocytes (hypertrophy) and/or an increase in preadipocyte and adipocyte number (hyperplasia) to accommodate excess energy intake. However, obesity is not solely defined by increases in adipocyte size and number. The turnover of adipose tissue cells also plays a crucial role in the development and progression of obesity. Cell turnover encompasses the processes of cell proliferation, differentiation, and apoptosis, which collectively regulate the overall cell population within adipose tissue. Lipid turnover represents another critical factor that influences how adipose tissue stores and releases energy. Our understanding of adipose tissue lipid turnover in humans remains limited due to the slow rate of turnover and methodological constraints. Nonetheless, disturbances in lipid metabolism are strongly associated with altered adipose tissue lipid turnover. In obesity, there is a decreased rate of triglyceride removal (lipolysis followed by oxidation), leading to the accumulation of triglycerides over time. This review provides a comprehensive summary of findings from both in vitro and in vivo methods used to study the turnover of adipose cells and lipids in metabolic health and disease. Understanding the mechanisms underlying cellular and lipid turnover in obesity is essential for developing strategies to mitigate the adverse effects of excess adiposity.
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Affiliation(s)
- Ivonne Palacios-Marin
- Endocrinology Department, Institut de Recerca Sant Joan de Déu, Esplugues, E-08950 Barcelona, Spain
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, E-08028 Barcelona, Spain
| | - Dolors Serra
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, E-08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, E-28029 Madrid, Spain
| | - Josep Jimenez-Chillarón
- Endocrinology Department, Institut de Recerca Sant Joan de Déu, Esplugues, E-08950 Barcelona, Spain
- Department of Physiological Sciences, School of Medicine, University of Barcelona, E-08907 L’Hospitalet, Spain
| | - Laura Herrero
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, E-08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, E-28029 Madrid, Spain
| | - Marijana Todorčević
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, E-08028 Barcelona, Spain
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9
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Brender JR, Assmann JC, Farthing DE, Saito K, Kishimoto S, Warrick KA, Maglakelidze N, Larus TL, Merkle H, Gress RE, Krishna MC, Buxbaum NP. In vivo deuterium magnetic resonance imaging of xenografted tumors following systemic administration of deuterated water. Sci Rep 2023; 13:14699. [PMID: 37679461 PMCID: PMC10485001 DOI: 10.1038/s41598-023-41163-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 08/23/2023] [Indexed: 09/09/2023] Open
Abstract
In vivo deuterated water (2H2O) labeling leads to deuterium (2H) incorporation into biomolecules of proliferating cells and provides the basis for its use in cell kinetics research. We hypothesized that rapidly proliferating cancer cells would become preferentially labeled with 2H and, therefore, could be visualized by deuterium magnetic resonance imaging (dMRI) following a brief period of in vivo systemic 2H2O administration. We initiated systemic 2H2O administration in two xenograft mouse models harboring either human colorectal, HT-29, or pancreatic, MiaPaCa-2, tumors and 2H2O level of ~ 8% in total body water (TBW). Three schemas of 2H2O administration were tested: (1) starting at tumor seeding and continuing for 7 days of in vivo growth with imaging on day 7, (2) starting at tumor seeding and continuing for 14 days of in vivo growth with imaging on day 14, and (3) initiation of labeling following a week of in vivo tumor growth and continuing until imaging was performed on day 14. Deuterium chemical shift imaging of the tumor bearing limb and contralateral control was performed on either day 7 of 14 after tumor seeding, as described. After 14 days of in vivo tumor growth and 7 days of systemic labeling with 2H2O, a clear deuterium contrast was demonstrated between the xenografts and normal tissue. Labeling in the second week after tumor implantation afforded the highest contrast between neoplastic and healthy tissue in both models. Systemic labeling with 2H2O can be used to create imaging contrast between tumor and healthy issue, providing a non-radioactive method for in vivo cancer imaging.
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Affiliation(s)
- Jeffrey R Brender
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Julian C Assmann
- Experimental Transplantation and Immunotherapy Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Don E Farthing
- Center for Immuno-Oncology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Keita Saito
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Shun Kishimoto
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Kathrynne A Warrick
- Experimental Transplantation and Immunotherapy Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Natella Maglakelidze
- Experimental Transplantation and Immunotherapy Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Terri L Larus
- Center for Immuno-Oncology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Hellmut Merkle
- Laboratory for Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Ronald E Gress
- Experimental Transplantation and Immunotherapy Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Murali C Krishna
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Nataliya P Buxbaum
- Experimental Transplantation and Immunotherapy Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
- Pediatric Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA.
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10
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Kim J, Seo S, Kim TY. Metabolic deuterium oxide (D 2O) labeling in quantitative omics studies: A tutorial review. Anal Chim Acta 2023; 1242:340722. [PMID: 36657897 DOI: 10.1016/j.aca.2022.340722] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/25/2022] [Accepted: 12/13/2022] [Indexed: 12/15/2022]
Abstract
Mass spectrometry (MS) is an invaluable tool for sensitive detection and characterization of individual biomolecules in omics studies. MS combined with stable isotope labeling enables the accurate and precise determination of quantitative changes occurring in biological samples. Metabolic isotope labeling, wherein isotopes are introduced into biomolecules through biosynthetic metabolism, is one of the main labeling strategies. Among the precursors employed in metabolic isotope labeling, deuterium oxide (D2O) is cost-effective and easy to implement in any biological systems. This tutorial review aims to explain the basic principle of D2O labeling and its applications in omics research. D2O labeling incorporates D into stable C-H bonds in various biomolecules, including nucleotides, proteins, lipids, and carbohydrates. Typically, D2O labeling is performed at low enrichment of 1%-10% D2O, which causes subtle changes in the isotopic distribution of a biomolecule, instead of the complete separation between labeled and unlabeled samples in a mass spectrum. D2O labeling has been employed in various omics studies to determine the metabolic flux, turnover rate, and relative quantification. Moreover, the advantages and challenges of D2O labeling and its future prospects in quantitative omics are discussed. The economy, versatility, and convenience of D2O labeling will be beneficial for the long-term omics studies for higher organisms.
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Affiliation(s)
- Jonghyun Kim
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju, 61005, South Korea
| | - Seungwoo Seo
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju, 61005, South Korea
| | - Tae-Young Kim
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju, 61005, South Korea.
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11
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Salvador AF, Shyu CR, Parks EJ. Measurement of lipid flux to advance translational research: evolution of classic methods to the future of precision health. EXPERIMENTAL & MOLECULAR MEDICINE 2022; 54:1348-1353. [PMID: 36075949 PMCID: PMC9534914 DOI: 10.1038/s12276-022-00838-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/22/2022] [Accepted: 07/12/2022] [Indexed: 02/08/2023]
Abstract
Over the past 70 years, the study of lipid metabolism has led to important discoveries in identifying the underlying mechanisms of chronic diseases. Advances in the use of stable isotopes and mass spectrometry in humans have expanded our knowledge of target molecules that contribute to pathologies and lipid metabolic pathways. These advances have been leveraged within two research paths, leading to the ability (1) to quantitate lipid flux to understand the fundamentals of human physiology and pathology and (2) to perform untargeted analyses of human blood and tissues derived from a single timepoint to identify lipidomic patterns that predict disease. This review describes the physiological and analytical parameters that influence these measurements and how these issues will propel the coming together of the two fields of metabolic tracing and lipidomics. The potential of data science to advance these fields is also discussed. Future developments are needed to increase the precision of lipid measurements in human samples, leading to discoveries in how individuals vary in their production, storage, and use of lipids. New techniques are critical to support clinical strategies to prevent disease and to identify mechanisms by which treatments confer health benefits with the overall goal of reducing the burden of human disease. Personalized tracking of how lipid (fat) metabolism changes over time could lead to improvements in the diagnosis and treatment of several diseases. Elizabeth Parks and colleagues from the University of Missouri, Columbia, USA, discuss the ways in which researchers use stable isotope labeling to monitor the kinetics of fatty acids and other lipids in the body. Usually, lipid quantities are measured only at a single timepoint, however the tracking of lipid turnover over time provides further diagnostic information. Aided by new techniques such as high-throughput mass spectrometry and machine learning, researchers are now able to continuously map total lipid contents in individual patients. The transition of measurements of lipid flux from the research laboratory to the doctor’s office will likely play a role in a new era of precision medicine.
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Affiliation(s)
- Amadeo F Salvador
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, 65212, USA.,Department of Medicine, Division of Gastroenterology and Hepatology, School of Medicine, University of Missouri, Columbia, MO, 65212, USA.,Department of Electrical Engineering and Computer Science, Institute for Data Science and Informatics, University of Missouri, Columbia, MO, 65211, USA
| | - Chi-Ren Shyu
- Department of Electrical Engineering and Computer Science, Institute for Data Science and Informatics, University of Missouri, Columbia, MO, 65211, USA
| | - Elizabeth J Parks
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, 65212, USA. .,Department of Medicine, Division of Gastroenterology and Hepatology, School of Medicine, University of Missouri, Columbia, MO, 65212, USA.
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12
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Jang J, Koh JH, Kim Y, Kim HJ, Park S, Chang Y, Jung J, Wolfe RR, Kim IY. Balanced Free Essential Amino Acids and Resistance Exercise Training Synergistically Improve Dexamethasone-Induced Impairments in Muscle Strength, Endurance, and Insulin Sensitivity in Mice. Int J Mol Sci 2022; 23:ijms23179735. [PMID: 36077132 PMCID: PMC9456044 DOI: 10.3390/ijms23179735] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/23/2022] [Accepted: 08/25/2022] [Indexed: 11/16/2022] Open
Abstract
Our previous study shows that an essential amino acid (EAA)-enriched diet attenuates dexamethasone (DEX)-induced declines in muscle mass and strength, as well as insulin sensitivity, but does not affect endurance. In the present study, we hypothesized that the beneficial effects will be synergized by adding resistance exercise training (RET) to EAA, and diet-free EAA would improve endurance. To test hypotheses, mice were randomized into the following four groups: control, EAA, RET, and EAA+RET. All mice except the control were subjected to DEX treatment. We evaluated the cumulative rate of myofibrillar protein synthesis (MPS) using 2H2O labeling and mass spectrometry. Neuromuscular junction (NMJ) stability, mitochondrial contents, and molecular signaling were demonstrated in skeletal muscle. Insulin sensitivity and glucose metabolism using 13C6-glucose tracing during oral glucose tolerance tests were analyzed. We found that EAA and RET synergistically improve muscle mass and/or strength, and endurance capacity, as well as insulin sensitivity, and glucose metabolism in DEX-treated muscle. These improvements are accomplished, in part, through improvements in myofibrillar protein synthesis, NMJ, fiber type preservation, and/or mitochondrial biogenesis. In conclusion, free EAA supplementation, particularly when combined with RET, can serve as an effective means that counteracts the adverse effects on muscle of DEX that are found frequently in clinical settings.
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Affiliation(s)
- Jiwoong Jang
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea
- Department of Internal Medicine, Gil Medical Center, Gachon University, Incheon 21565, Korea
| | - Jin-Ho Koh
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon 21565, Korea
| | - Yeongmin Kim
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Korea
| | - Hee-Joo Kim
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Korea
| | - Sanghee Park
- Department of Internal Medicine, Gil Medical Center, Gachon University, Incheon 21565, Korea
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon 21565, Korea
| | - Yewon Chang
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Korea
| | - Jiyeon Jung
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Korea
| | - Robert R. Wolfe
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Il-Young Kim
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon 21565, Korea
- Correspondence: ; Tel.: +82-32-899-6685
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Abstract
Recent technological developments have allowed determination of the age of fat cells and their lipids in adult humans. In contrast to prior views, this has demonstrated a high turnover rate of the fat cells (10%/year) and their unilocular lipid droplets (six times/10 years). Fat cell turnover is increased in obesity and when adipose tissue is composed of many but small adipocytes (hyperplasia, a benign adipose phenotype). While fat mass gain increases adipocyte number and size, only the latter is altered (decreased) after weight loss, which may facilitate weight regain. Fat cell lipid turnover is attenuated in subjects with excess body fat. In the subcutaneous region, this dysregulation occurs already in the overweight state while in the visceral depot, it is only observed in severe obesity. This may explain why the latter depot is particularly pernicious in the overweight/obese state as it allows for more rapid lipid fluxes between visceral fat and the liver. Adipose lipid turnover decreases during ageing due to impaired breakdown (lipolysis) of stored triglycerides. If this decline is not compensated by reduced adipocyte lipid uptake, bodyweight will increase over time. In concordance with this, low lipolysis rates are a risk factor for future weight gain and glucose intolerance. Adipose lipid turnover is also decreased in insulin resistance and certain forms of dyslipidemia. Altogether, adult human adipose tissue is in a highly dynamic state. Alterations in the turnover of fat cells and their lipids are therefore novel factors to consider in the pathophysiology of common metabolic disorders.
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Affiliation(s)
- Peter Arner
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Mikael Rydén
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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14
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Ward CP, Peng L, Yuen S, Halstead J, Palacios H, Nyangau E, Mohammed H, Ziari N, Dandan M, Frakes AE, Gildea HK, Dillin A, Hellerstein M. Aging alters the metabolic flux signature of the ER-unfolded protein response in vivo in mice. Aging Cell 2022; 21:e13558. [PMID: 35170180 PMCID: PMC8920450 DOI: 10.1111/acel.13558] [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: 05/20/2021] [Revised: 11/16/2021] [Accepted: 12/25/2021] [Indexed: 01/23/2023] Open
Abstract
Age is a risk factor for numerous diseases, including neurodegenerative diseases, cancers, and diabetes. Loss of protein homeostasis is a central hallmark of aging. Activation of the endoplasmic reticulum unfolded protein response (UPRER ) includes changes in protein translation and membrane lipid synthesis. Using stable isotope labeling, a flux "signature" of the UPRER in vivo in mouse liver was developed by inducing ER stress with tunicamycin and measuring rates of both proteome-wide translation and de novo lipogenesis. Several changes in protein synthesis across ontologies were noted with age, including a more dramatic suppression of translation under ER stress in aged mice as compared with young mice. Binding immunoglobulin protein (BiP) synthesis rates and mRNA levels were increased more in aged than young mice. De novo lipogenesis rates decreased under ER stress conditions in aged mice, including both triglyceride and phospholipid fractions. In young mice, a significant reduction was seen only in the triglyceride fraction. These data indicate that aged mice have an exaggerated metabolic flux response to ER stress, which may indicate that aging renders the UPRER less effective in resolving proteotoxic stress.
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Affiliation(s)
- Catherine P. Ward
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Lucy Peng
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Samuel Yuen
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - John Halstead
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Hector Palacios
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Edna Nyangau
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Hussein Mohammed
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Naveed Ziari
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Mohamad Dandan
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Ashley E. Frakes
- Department of Molecular and Cellular BiologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Holly K. Gildea
- Department of Molecular and Cellular BiologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Andrew Dillin
- Department of Molecular and Cellular BiologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Marc K. Hellerstein
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
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15
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Duncan O, Millar AH. Day and night isotope labelling reveal metabolic pathway specific regulation of protein synthesis rates in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:745-763. [PMID: 34997626 DOI: 10.1111/tpj.15661] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 12/14/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Plants have a diurnal separation of metabolic fluxes and a need for differential maintenance of protein machinery in the day and night. To directly assess the output of the translation process and to estimate the ATP investment involved, the individual rates of protein synthesis and degradation of hundreds of different proteins need to be measured simultaneously. We quantified protein synthesis and degradation through pulse labelling with heavy hydrogen in Arabidopsis thaliana rosettes to allow such an assessment of ATP investment in leaf proteome homeostasis on a gene-by-gene basis. Light-harvesting complex proteins were synthesised and degraded much faster in the day (approximately 10:1), while carbon metabolism and vesicle trafficking components were translated at similar rates day or night. Few leaf proteins changed in abundance between the day and the night despite reduced protein synthesis rates at night, indicating that protein degradation rates are tightly coordinated. The data reveal how the pausing of photosystem synthesis and degradation at night allows the redirection of a decreased energy budget to a selective night-time maintenance schedule.
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Affiliation(s)
- Owen Duncan
- ARC Centre of Excellence in Plant Energy Biology, Perth, WA, Australia
- Western Australian Proteomics, The University Western Australia, Perth, WA, Australia
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, Perth, WA, Australia
- Western Australian Proteomics, The University Western Australia, Perth, WA, Australia
- School of Molecular Sciences, The University of Western Australia, Perth, WA, Australia
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16
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Ward CP, Peng L, Yuen S, Chang M, Karapetyan R, Nyangau E, Mohammed H, Palacios H, Ziari N, Joe LK, Frakes AE, Dandan M, Dillin A, Hellerstein MK. ER Unfolded Protein Response in Liver In Vivo Is Characterized by Reduced, Not Increased, De Novo Lipogenesis and Cholesterol Synthesis Rates with Uptake of Fatty Acids from Adipose Tissue: Integrated Gene Expression, Translation Rates and Metabolic Fluxes. Int J Mol Sci 2022; 23:ijms23031073. [PMID: 35162995 PMCID: PMC8835023 DOI: 10.3390/ijms23031073] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/14/2022] [Accepted: 01/14/2022] [Indexed: 02/06/2023] Open
Abstract
The unfolded protein response in the endoplasmic reticulum (UPRER) is involved in a number of metabolic diseases. Here, we characterize UPRER-induced metabolic changes in mouse livers in vivo through metabolic labeling and mass spectrometric analysis of lipid and proteome-wide fluxes. We induced UPRER by tunicamycin administration and measured synthesis rates of proteins, fatty acids and cholesterol, as well as RNA-seq. Contrary to reports in isolated cells, hepatic de novo lipogenesis and cholesterogenesis were markedly reduced, as were mRNA levels and synthesis rates of lipogenic proteins. H&E staining showed enrichment with lipid droplets while electron microscopy revealed ER morphological changes. Interestingly, the pre-labeling of adipose tissue prior to UPRER induction resulted in the redistribution of labeled fatty acids from adipose tissue to the liver, with replacement by unlabeled glycerol in the liver acylglycerides, indicating that the liver uptake was of free fatty acids, not whole glycerolipids. The redistribution of adipose fatty acids to the liver was not explicable by altered plasma insulin, increased fatty acid levels (lipolysis) or by reduced food intake. Synthesis of most liver proteins was suppressed under UPRER conditions, with the exception of BiP, other chaperones, protein disulfide isomerases, and proteins of ribosomal biogenesis. Protein synthesis rates generally, but not always, paralleled changes in mRNA. In summary, this combined approach, linking static changes with fluxes, revealed an integrated reduction of lipid and cholesterol synthesis pathways, from gene expression to translation and metabolic flux rates, under UPRER conditions. The reduced lipogenesis does not parallel human fatty liver disease. This approach provides powerful tools to characterize metabolic processes underlying hepatic UPRER in vivo.
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Affiliation(s)
- Catherine P. Ward
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
| | - Lucy Peng
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
| | - Samuel Yuen
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
| | - Michael Chang
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
| | - Rozalina Karapetyan
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
| | - Edna Nyangau
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
| | - Hussein Mohammed
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
| | - Hector Palacios
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
| | - Naveed Ziari
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
| | - Larry K. Joe
- Department of Molecular and Cellular Biology, University of California, Berkeley, CA 92093, USA; (L.K.J.); (A.E.F.); (A.D.)
| | - Ashley E. Frakes
- Department of Molecular and Cellular Biology, University of California, Berkeley, CA 92093, USA; (L.K.J.); (A.E.F.); (A.D.)
| | - Mohamad Dandan
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
| | - Andrew Dillin
- Department of Molecular and Cellular Biology, University of California, Berkeley, CA 92093, USA; (L.K.J.); (A.E.F.); (A.D.)
| | - Marc K. Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 92093, USA; (C.P.W.); (L.P.); (S.Y.); (M.C.); (R.K.); (E.N.); (H.M.); (H.P.); (N.Z.); (M.D.)
- Correspondence:
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17
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Baumann A, Denninger AR, Domin M, Demé B, Kirschner DA. Metabolically-incorporated deuterium in myelin localized by neutron diffraction and identified by mass spectrometry. Curr Res Struct Biol 2022; 4:231-245. [PMID: 35941866 PMCID: PMC9356250 DOI: 10.1016/j.crstbi.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 11/25/2022] Open
Abstract
Myelin is a natural and dynamic multilamellar membrane structure that continues to be of significant biological and neurological interest, especially with respect to its biosynthesis and assembly during its normal formation, maintenance, and pathological breakdown. To explore the usefulness of neutron diffraction in the structural analysis of myelin, we investigated the use of in vivo labeling by metabolically incorporating non-toxic levels of deuterium (2H; D) via drinking water into a pregnant dam (D-dam) and her developing embryos. All of the mice were sacrificed when the pups (D-pups) were 55 days old. Myelinated sciatic nerves were dissected, fixed in glutaraldehyde and examined by neutron diffraction. Parallel samples that were unfixed (trigeminal nerves) were frozen for mass spectrometry (MS). The diffraction patterns of the nerves from deuterium-fed mice (D-mice) vs. the controls (H-mice) had major differences in the intensities of the Bragg peaks but no appreciable differences in myelin periodicity. Neutron scattering density profiles showed an appreciable increase in density at the center of the lipid-rich membrane bilayer. This increase was greater in D-pups than in D-dam, and its localization was consistent with deuteration of lipid hydrocarbon, which predominates over transmembrane protein in myelin. MS analysis of the lipids isolated from the trigeminal nerves demonstrated that in the pups the percentage of lipids that had one or more deuterium atoms was uniformly high across lipid species (97.6% ± 2.0%), whereas in the mother the lipids were substantially less deuterated (60.6% ± 26.4%) with levels varying among lipid species and subspecies. The mass distribution pattern of deuterium-containing isotopologues indicated the fraction (in %) of each lipid (sub-)species having one or more deuteriums incorporated: in the D-pups, the pattern was always bell-shaped, and the average number of D atoms ranged from a low of ∼4 in fatty acid to a high of ∼9 in cerebroside. By contrast, in D-dam most lipids had more complex, overlapping distributions that were weighted toward a lower average number of deuteriums, which ranged from a low of ∼3–4 in fatty acid and in one species of sulfatide to a high of 6–7 in cerebroside and sphingomyelin. The consistently high level of deuteration in D-pups can be attributed to their de novo lipogenesis during gestation and rapid, postnatal myelination. The widely varying levels of deuteration in D-dam, by contrast, likely depends on the relative metabolic stability of the particular lipid species during myelin maintenance. Our current findings demonstrate that stably-incorporated D label can be detected and localized using neutron diffraction in a complex tissue such as myelin; and moreover, that MS can be used to screen a broad range of deuterated lipid species to monitor differential rates of lipid turnover. In addition to helping to develop a comprehensive understanding of the de novo synthesis and turnover of specific lipids in normal and abnormal myelin, our results also suggest application to studies on myelin proteins (which constitute only 20–30% by dry mass of the myelin, vs. 70–80% for lipid), as well as more broadly to the molecular constituents of other biological tissues. Deuterium metabolically assimilated into gestating mouse pups via drinking water. Neutron diffraction localized deuterium to middle of myelin membrane bilayers. Mass spectrometry identified 26 deuterated lipid species as myelinic. Myelin of pups substantially more deuterated than that of their dam. Deuterium differentially distributed among lipid species and subspecies. De novo lipid biogenesis vs. steady-state maintenance readily distinguished. Novel paradigm suggests application to animal models of human myelinopathies.
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18
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Beals JW, Smith GI, Shankaran M, Fuchs A, Schweitzer GG, Yoshino J, Field T, Matthews M, Nyangau E, Morozov D, Mittendorfer B, Hellerstein MK, Klein S. Increased Adipose Tissue Fibrogenesis, Not Impaired Expandability, Is Associated With Nonalcoholic Fatty Liver Disease. Hepatology 2021; 74:1287-1299. [PMID: 33743554 PMCID: PMC8559258 DOI: 10.1002/hep.31822] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/07/2021] [Accepted: 03/14/2021] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND AIMS It is proposed that impaired expansion of subcutaneous adipose tissue (SAT) and an increase in adipose tissue (AT) fibrosis causes ectopic lipid accumulation, insulin resistance (IR), and metabolically unhealthy obesity. We therefore evaluated whether a decrease in SAT expandability, assessed by measuring SAT lipogenesis (triglyceride [TG] production), and an increase in SAT fibrogenesis (collagen production) are associated with NAFLD and IR in persons with obesity. APPROACH AND RESULTS In vivo abdominal SAT lipogenesis and fibrogenesis, expression of SAT genes involved in extracellular matrix (ECM) formation, and insulin sensitivity were assessed in three groups of participants stratified by adiposity and intrahepatic TG (IHTG) content: (1) healthy lean with normal IHTG content (Lean-NL; n = 12); (2) obese with normal IHTG content and normal glucose tolerance (Ob-NL; n = 25); and (3) obese with NAFLD and abnormal glucose metabolism (Ob-NAFLD; n = 25). Abdominal SAT TG synthesis rates were greater (P < 0.05) in both the Ob-NL (65.9 ± 4.6 g/wk) and Ob-NAFLD groups (71.1 ± 6.7 g/wk) than the Lean-NL group (16.2 ± 2.8 g/wk) without a difference between the Ob-NL and Ob-NAFLD groups. Abdominal SAT collagen synthesis rate and the composite expression of genes encoding collagens progressively increased from the Lean-NL to the Ob-NL to the Ob-NAFLD groups and were greater in the Ob-NAFLD than the Ob-NL group (P < 0.05). Composite expression of collagen genes was inversely correlated with both hepatic and whole-body insulin sensitivity (P < 0.001). CONCLUSIONS AT expandability is not impaired in persons with obesity and NAFLD. However, SAT fibrogenesis is greater in persons with obesity and NAFLD than in those with obesity and normal IHTG content, and is inversely correlated with both hepatic and whole-body insulin sensitivity.
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Affiliation(s)
- Joseph W. Beals
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St Louis, MO
| | - Gordon I. Smith
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St Louis, MO
| | | | - Anja Fuchs
- Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - George G. Schweitzer
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St Louis, MO
| | - Jun Yoshino
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St Louis, MO
| | - Tyler Field
- University of California Berkeley, Berkeley, CA
| | | | | | - Darya Morozov
- Department of Radiology, Washington University School of Medicine, St Louis, MO
| | - Bettina Mittendorfer
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St Louis, MO
| | | | - Samuel Klein
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St Louis, MO
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Maharjan P, Beitia A, Weil J, Suesuttajit N, Hilton K, Caldas J, Umberson C, Martinez D, Kong B, Owens CM, Coon C. Woody breast myopathy broiler show age-dependent adaptive differential gene expression in Pectoralis major and altered in-vivo triglyceride kinetics in adipogenic tissues. Poult Sci 2021; 100:101092. [PMID: 34087697 PMCID: PMC8182436 DOI: 10.1016/j.psj.2021.101092] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 02/17/2021] [Accepted: 03/04/2021] [Indexed: 11/26/2022] Open
Abstract
A study was conducted to understand the differentially expressed genes in Pectoralis (P) major under woody breast (WB) myopathy condition in a high yielding broiler strain using RNA-sequencing at the growing (d 21) and finishing (d 42 and d 56) grow-out ages. Follow-up study was conducted to understand the in vivo triglyceride (TG) synthesis (d 49) occurring in adipogenic tissues using deuterium oxide (2H2O) as a metabolic tracer. Results indicated the top physiological systems affected in myopathy broiler were related to the musculo-skeletal system (d 21, 42, and 56) and cardiovascular system (d 42 and 56). Ubiquitin-specific proteases are expressed higher in myopathy broiler at d 21 (OTUD1) and d 42 (SACS) that potentially indicated higher degradation of muscle protein occurring at those ages. While genes related to transcription factors and muscle cell differentiation (ZNF234, BTG2) and muscle growth (IGF1) were upregulated with myopathy broiler suggesting concurrent muscle fiber regeneration. The downregulation of PYGB and MGAM genes related to carbohydrate transport and metabolism at d 42 potentially indicated nutrient-deficient state of myopathy affected fibers; whereas the nutrient-deficient physiological state of cells seemed to be counteracted by up-regulation of genes related to carbohydrate (ALDOB, GPD1L2) at d 56. There was a reduced (P < 0.05) in vivo TG synthesis in liver of the myopathy broiler (0.123 %/hr) compared to non-myopathy broiler (0.197 %/hr). The majority of TG synthesized in liver with myopathy broiler could conceivably be delivered to P. major (rather than to abdominal fat pad storage) to fulfil the increased energy need of muscle cells (via TG lipolysis and fatty acid [FA] oxidation). The increased utilization of FAs in the WB affected muscle could result in reduced secretion of FAs into blood circulation leading to sub-optimal availability of FAs for re-esterification for TG synthesis in liver. Results indicated that myopathy broiler at later age (d 56) of grow-out period were synchronously going through adaptive physiological processes of feedback responses to adverse cellular states.
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Affiliation(s)
- Pramir Maharjan
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | | | - Jordan Weil
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Nawin Suesuttajit
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Katie Hilton
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | | | - Cole Umberson
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Diego Martinez
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Byungwhi Kong
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Casey M Owens
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Craig Coon
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
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20
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Myostatin Inhibition-Induced Increase in Muscle Mass and Strength Was Amplified by Resistance Exercise Training, and Dietary Essential Amino Acids Improved Muscle Quality in Mice. Nutrients 2021; 13:nu13051508. [PMID: 33947024 PMCID: PMC8146053 DOI: 10.3390/nu13051508] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/23/2021] [Accepted: 04/27/2021] [Indexed: 12/16/2022] Open
Abstract
It has been frequently reported that myostatin inhibition increases muscle mass, but decreases muscle quality (i.e., strength/muscle mass). Resistance exercise training (RT) and essential amino acids (EAAs) are potent anabolic stimuli that synergistically increase muscle mass through changes in muscle protein turnover. In addition, EAAs are known to stimulate mitochondrial biogenesis. We have investigated if RT amplifies the anabolic potential of myostatin inhibition while EAAs enhance muscle quality through stimulations of mitochondrial biogenesis and/or muscle protein turnover. Mice were assigned into ACV (myostatin inhibitor), ACV+EAA, ACV+RT, ACV+EAA +RT, or control (CON) over 4 weeks. RT, but not EAA, increased muscle mass above ACV. Despite differences in muscle mass gain, myofibrillar protein synthesis was stimulated similarly in all vs. CON, suggesting a role for changes in protein breakdown in muscle mass gains. There were increases in MyoD expression but decreases in Atrogin-1/MAFbx expression in ACV+EAA, ACV+RT, and ACV+EAA+RT vs. CON. EAA increased muscle quality (e.g., grip strength and maximal carrying load) without corresponding changes in markers of mitochondrial biogenesis and neuromuscular junction stability. In conclusion, RT amplifies muscle mass and strength through changes in muscle protein turnover in conjunction with changes in implicated signaling, while EAAs enhance muscle quality through unknown mechanisms.
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21
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Lin P, Dai L, Crooks DR, Neckers LM, Higashi RM, Fan TWM, Lane AN. NMR Methods for Determining Lipid Turnover via Stable Isotope Resolved Metabolomics. Metabolites 2021; 11:202. [PMID: 33805301 PMCID: PMC8065598 DOI: 10.3390/metabo11040202] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 11/28/2022] Open
Abstract
Lipids comprise diverse classes of compounds that are important for the structure and properties of membranes, as high-energy fuel sources and as signaling molecules. Therefore, the turnover rates of these varied classes of lipids are fundamental to cellular function. However, their enormous chemical diversity and dynamic range in cells makes detailed analysis very complex. Furthermore, although stable isotope tracers enable the determination of synthesis and degradation of complex lipids, the numbers of distinguishable molecules increase enormously, which exacerbates the problem. Although LC-MS-MS (Liquid Chromatography-Tandem Mass Spectrometry) is the standard for lipidomics, NMR can add value in global lipid analysis and isotopomer distributions of intact lipids. Here, we describe new developments in NMR analysis for assessing global lipid content and isotopic enrichment of mixtures of complex lipids for two cell lines (PC3 and UMUC3) using both 13C6 glucose and 13C5 glutamine tracers.
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Affiliation(s)
- Penghui Lin
- Center for Environmental and Systems Biochemistry, University of Kentucky, 789 S. Limestone St, Lexington, KY 40536, USA; (P.L.); (R.M.H.); (T.W-M.F.)
| | - Li Dai
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (L.D.); (D.R.C.); (L.M.N.)
| | - Daniel R. Crooks
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (L.D.); (D.R.C.); (L.M.N.)
| | - Leonard M. Neckers
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (L.D.); (D.R.C.); (L.M.N.)
| | - Richard M. Higashi
- Center for Environmental and Systems Biochemistry, University of Kentucky, 789 S. Limestone St, Lexington, KY 40536, USA; (P.L.); (R.M.H.); (T.W-M.F.)
- Department Toxicology & Cancer Biology, University of Kentucky, 789 S. Limestone St, Lexington, KY 40536, USA
| | - Teresa W-M. Fan
- Center for Environmental and Systems Biochemistry, University of Kentucky, 789 S. Limestone St, Lexington, KY 40536, USA; (P.L.); (R.M.H.); (T.W-M.F.)
- Department Toxicology & Cancer Biology, University of Kentucky, 789 S. Limestone St, Lexington, KY 40536, USA
| | - Andrew N. Lane
- Center for Environmental and Systems Biochemistry, University of Kentucky, 789 S. Limestone St, Lexington, KY 40536, USA; (P.L.); (R.M.H.); (T.W-M.F.)
- Department Toxicology & Cancer Biology, University of Kentucky, 789 S. Limestone St, Lexington, KY 40536, USA
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22
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Downes DP, Kasumov T, Daurio NA, Wood NB, Previs MJ, Sheth PR, McLaren DG, Previs SF. Isotope Fractionation during Gas Chromatography Can Enhance Mass Spectrometry-Based Measures of 2H-Labeling of Small Molecules. Metabolites 2020; 10:E474. [PMID: 33233825 PMCID: PMC7699861 DOI: 10.3390/metabo10110474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/06/2020] [Accepted: 11/12/2020] [Indexed: 11/16/2022] Open
Abstract
Stable isotope tracers can be used to quantify the activity of metabolic pathways. Specifically, 2H-water is quite versatile, and its incorporation into various products can enable measurements of carbohydrate, lipid, protein and nucleic acid kinetics. However, since there are limits on how much 2H-water can be administered and since some metabolic processes may be slow, it is possible that one may be challenged with measuring small changes in isotopic enrichment. We demonstrate an advantage of the isotope fractionation that occurs during gas chromatography, namely, setting tightly bounded integration regions yields a powerful approach for determining isotope ratios. We determined how the degree of isotope fractionation, chromatographic peak width and mass spectrometer dwell time can increase the apparent isotope labeling. Relatively simple changes in the logic surrounding data acquisition and processing can enhance gas chromatography-mass spectrometry measures of low levels of 2H-labeling, this is especially useful when asymmetrical peaks are recorded at low signal:background. Although we have largely focused attention on alanine (which is of interest in studies of protein synthesis), it should be possible to extend the concepts to other analytes and/or hardware configurations.
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Affiliation(s)
- Daniel P. Downes
- Department of Chemistry, Merck & Co., Inc., Kenilworth, NJ 07033, USA; (D.P.D.); (N.A.D.); (P.R.S.); (D.G.M.)
| | - Takhar Kasumov
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH 44272, USA;
| | - Natalie A. Daurio
- Department of Chemistry, Merck & Co., Inc., Kenilworth, NJ 07033, USA; (D.P.D.); (N.A.D.); (P.R.S.); (D.G.M.)
| | - Neil B. Wood
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT 05405, USA; (N.B.W.); (M.J.P.)
| | - Michael J. Previs
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT 05405, USA; (N.B.W.); (M.J.P.)
| | - Payal R. Sheth
- Department of Chemistry, Merck & Co., Inc., Kenilworth, NJ 07033, USA; (D.P.D.); (N.A.D.); (P.R.S.); (D.G.M.)
| | - David G. McLaren
- Department of Chemistry, Merck & Co., Inc., Kenilworth, NJ 07033, USA; (D.P.D.); (N.A.D.); (P.R.S.); (D.G.M.)
| | - Stephen F. Previs
- Department of Chemistry, Merck & Co., Inc., Kenilworth, NJ 07033, USA; (D.P.D.); (N.A.D.); (P.R.S.); (D.G.M.)
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23
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Kim IY, Park S, Jang J, Wolfe RR. Quantifications of Lipid Kinetics In Vivo Using Stable Isotope Tracer Methodology. J Lipid Atheroscler 2020; 9:110-123. [PMID: 32821725 PMCID: PMC7379070 DOI: 10.12997/jla.2020.9.1.110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/19/2019] [Accepted: 12/29/2019] [Indexed: 12/16/2022] Open
Abstract
Like other bodily materials, lipids such as plasma triacylglycerol, cholesterols, and free fatty acids are in a dynamic state of constant turnover (i.e., synthesis, breakdown, oxidation, and/or conversion to other compounds) as essential processes for achieving dynamic homeostasis in the body. However, dysregulation of lipid turnover can lead to clinical conditions such as obesity, fatty liver disease, and dyslipidemia. Assessment of “snap-shot” information on lipid metabolism (e.g., tissue contents of lipids, abundance of mRNA and protein and/or signaling molecules) are often used in clinical and research settings, and can help to understand one's health and disease status. However, such “snapshots” do not provide critical information on dynamic nature of lipid metabolism, and therefore may miss “true” origin of the dysregulation implicated in related diseases. In this regard, stable isotope tracer methodology can provide the in vivo kinetic information of lipid metabolism. Combining with “static” information, knowledge of lipid kinetics can enable the acquisition of in depth understanding of lipid metabolism in relation to various health and disease status. This in turn facilitates the development of effective therapeutic approaches (e.g., exercise, nutrition, and/or drugs). In this review we will discuss 1) the importance of obtaining kinetic information for a better understanding of lipid metabolism, 2) basic principles of stable isotope tracer methodologies that enable exploration of “lipid kinetics” in vivo, and 3) quantification of some aspects of lipid kinetics in vivo with numerical examples.
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Affiliation(s)
- Il-Young Kim
- Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, College of Medicine, Gachon University, Incheon, Korea
| | - Sanghee Park
- Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, College of Medicine, Gachon University, Incheon, Korea
| | - Jiwoong Jang
- Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, College of Medicine, Gachon University, Incheon, Korea
| | - Robert R Wolfe
- Department of Geriatrics, Center for Translational Research in Aging & Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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24
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Milutinović DV, Brkljačić J, Teofilović A, Bursać B, Nikolić M, Gligorovska L, Kovačević S, Djordjevic A, Preitner F, Tappy L, Matić G, Veličković N. Chronic Stress Potentiates High Fructose-Induced Lipogenesis in Rat Liver and Kidney. Mol Nutr Food Res 2020; 64:e1901141. [PMID: 32379936 DOI: 10.1002/mnfr.201901141] [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: 11/06/2019] [Revised: 03/16/2020] [Indexed: 12/15/2022]
Abstract
SCOPE Intake of fructose-sweetened beverages and chronic stress (CS) both increase risk of cardiometabolic diseases. The aim is to investigate whether these factors synergistically perturb lipid metabolism in rat liver and kidney. METHODS AND RESULTS Fractional de novo lipogenesis (fDNL), intrahepatic- and intrarenal-triglycerides (IHTG and IRTG), de novo palmitate (DNPalm) content, FA composition, VLDL-TGs kinetics, and key metabolic gene expression at the end of the feeding and non-feeding phases in rats exposed to standard chow diet, chow diet + CS, 20% liquid high-fructose supplementation (HFr), or HFr+CS are measured. HFr induces hypertriglyceridemia, up-regulates fructose-metabolism and gluconeogenic enzymes, increases IHTG and DNPalm content in IHTG and IRTG, and augments fDNL at the end of the feeding phase. These changes are diminished after the non-feeding phase. CS does not exert such effects, but when combined with HFr, it reduces IHTG and visceral adiposity, enhances lipogenic gene expression and fDNL, and increases VLDL-DNPalm secretion. CONCLUSION Liquid high-fructose supplementation increases IHTG and VLDL-TG secretion after the feeding phase, the latter being the result of stimulated hepatic and renal DNL. Chronic stress potentiates the effects of high fructose on fDNL and export of newly synthesized VLDL-TGs, and decreases fructose-induced intrahepatic TG accumulation after the feeding phase.
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Affiliation(s)
- Danijela Vojnović Milutinović
- Department of Biochemistry, Institute for Biological Research "Siniša Stanković"-National Institute of Republic of Serbia, University of Belgrade, 142 Despot Stefan Blvd., Belgrade, 11000, Serbia
| | - Jelena Brkljačić
- Department of Biochemistry, Institute for Biological Research "Siniša Stanković"-National Institute of Republic of Serbia, University of Belgrade, 142 Despot Stefan Blvd., Belgrade, 11000, Serbia
| | - Ana Teofilović
- Department of Biochemistry, Institute for Biological Research "Siniša Stanković"-National Institute of Republic of Serbia, University of Belgrade, 142 Despot Stefan Blvd., Belgrade, 11000, Serbia
| | - Biljana Bursać
- Department of Biochemistry, Institute for Biological Research "Siniša Stanković"-National Institute of Republic of Serbia, University of Belgrade, 142 Despot Stefan Blvd., Belgrade, 11000, Serbia
| | - Marina Nikolić
- Department of Biochemistry, Institute for Biological Research "Siniša Stanković"-National Institute of Republic of Serbia, University of Belgrade, 142 Despot Stefan Blvd., Belgrade, 11000, Serbia
| | - Ljupka Gligorovska
- Department of Biochemistry, Institute for Biological Research "Siniša Stanković"-National Institute of Republic of Serbia, University of Belgrade, 142 Despot Stefan Blvd., Belgrade, 11000, Serbia
| | - Sanja Kovačević
- Department of Biochemistry, Institute for Biological Research "Siniša Stanković"-National Institute of Republic of Serbia, University of Belgrade, 142 Despot Stefan Blvd., Belgrade, 11000, Serbia
| | - Ana Djordjevic
- Department of Biochemistry, Institute for Biological Research "Siniša Stanković"-National Institute of Republic of Serbia, University of Belgrade, 142 Despot Stefan Blvd., Belgrade, 11000, Serbia
| | - Frederic Preitner
- Mouse Metabolic Facility (MEF), Center for Integrative Genomics, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Luc Tappy
- Department of Physiology, University of Lausanne, UNIL-CHUV, Rue du Bugnon 7, Lausanne, CH-1005, Switzerland
| | - Gordana Matić
- Department of Biochemistry, Institute for Biological Research "Siniša Stanković"-National Institute of Republic of Serbia, University of Belgrade, 142 Despot Stefan Blvd., Belgrade, 11000, Serbia
| | - Nataša Veličković
- Department of Biochemistry, Institute for Biological Research "Siniša Stanković"-National Institute of Republic of Serbia, University of Belgrade, 142 Despot Stefan Blvd., Belgrade, 11000, Serbia
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25
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Miller BF, Reid JJ, Price JC, Lin HJL, Atherton PJ, Smith K. CORP: The use of deuterated water for the measurement of protein synthesis. J Appl Physiol (1985) 2020; 128:1163-1176. [PMID: 32213116 DOI: 10.1152/japplphysiol.00855.2019] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The use of deuterium oxide (D2O) has greatly expanded the scope of what is possible for the measurement of protein synthesis. The greatest asset of D2O labeling is that it facilitates the measurement of synthesis rates over prolonged periods of time from single proteins through integrated tissue-based measurements. Because the ease of administration, the method is amenable for use in a variety of models and conditions. Although the method adheres to the same rules as other isotope methods, the flexibility can create conditions that are not the same as other approaches and thus requires careful execution to maintain validity and reliability. For this CORP article, we provide a history that gave rise to the method and discuss the advantages and disadvantages of the method, the critical assumptions, guidelines, and best practices based on instrumentation, models, and experimental design. The goal of this CORP article is to propagate additional use of D2O in a manner that produces reliable and valid data.
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Affiliation(s)
- Benjamin F Miller
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma
| | - Justin J Reid
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma
| | - John C Price
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
| | - Hsien-Jung L Lin
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
| | - Philip J Atherton
- MRC-ARUK Center for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - Kenneth Smith
- MRC-ARUK Center for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, United Kingdom
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26
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Histone demethylase JMJD1C is phosphorylated by mTOR to activate de novo lipogenesis. Nat Commun 2020; 11:796. [PMID: 32034158 PMCID: PMC7005700 DOI: 10.1038/s41467-020-14617-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 01/20/2020] [Indexed: 01/28/2023] Open
Abstract
Fatty acid and triglyceride synthesis increases greatly in response to feeding and insulin. This lipogenic induction involves coordinate transcriptional activation of various enzymes in lipogenic pathway, including fatty acid synthase and glycerol-3-phosphate acyltransferase. Here, we show that JMJD1C is a specific histone demethylase for lipogenic gene transcription in liver. In response to feeding/insulin, JMJD1C is phosphorylated at T505 by mTOR complex to allow direct interaction with USF-1 for recruitment to lipogenic promoter regions. Thus, by demethylating H3K9me2, JMJD1C alters chromatin accessibility to allow transcription. Consequently, JMJD1C promotes lipogenesis in vivo to increase hepatic and plasma triglyceride levels, showing its role in metabolic adaption for activation of the lipogenic program in response to feeding/insulin, and its contribution to development of hepatosteatosis resulting in insulin resistance. In response to insulin, liver cells increase de novo lipogenesis via the transcription factors USF-1 and SREBP. Here the authors show that USF-1 recruits JMJD1C, after its phosphorylation by mTOR, to lipogenic promoters where JMJD1C demethylates histone H3, contributing to lipogenesis by an epigenetic mechanism.
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27
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Kim J, Kang D, Lee SK, Kim TY. Deuterium Oxide Labeling for Global Omics Relative Quantification: Application to Lipidomics. Anal Chem 2019; 91:8853-8863. [PMID: 31246424 DOI: 10.1021/acs.analchem.9b00086] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel quantitative mass spectrometric method based on partial metabolic deuterium oxide (D2O) labeling, named "Deuterium Oxide Labeling for Global Omics Relative Quantification (DOLGOReQ)", was developed for relative quantification of lipids on a global scale. To assess the precision and robustness of DOLGOReQ, labeled and unlabeled lipids from HeLa cells were mixed in various ratios based on their cell numbers. Using in-house software developed for automated high-throughput data analysis of DOLGOReQ, the number of detectable mass isotopomers and the degree of deuterium labeling were exploited to filter out low quality quantification results. Quantification of an equimolar mixture of HeLa cell lipids exhibited high reproducibility and accuracy across multiple biological and technical replicates. Two orders of magnitude of effective dynamic range for reasonable relative quantification could be established with HeLa cells mixed from 10:1 to 1:10 ratios between labeled and unlabeled samples. The quantification precision of DOLGOReQ was also illustrated with lipids commonly detected in both positive and negative ion modes. Finally, quantification performance of DOLGOReQ was demonstrated in a biological sample by measuring the relative change in the lipidome of HeLa cells under normal and hypoxia conditions.
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Affiliation(s)
- Jonghyun Kim
- School of Earth Sciences and Environmental Engineering , Gwangju Institute of Science and Technology , Gwangju 61005 , Republic of Korea
| | - Dukjin Kang
- Center for Bioanalysis, Division of Chemical and Medical Metrology , Korea Research Institute of Standards and Science , Daejeon 34113 , Republic of Korea
| | - Sung Ki Lee
- Department of Obstetrics and Gynecology , College of Medicine, Konyang University , Daejeon 35365 , Republic of Korea
| | - Tae-Young Kim
- School of Earth Sciences and Environmental Engineering , Gwangju Institute of Science and Technology , Gwangju 61005 , Republic of Korea
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28
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Krois CR, Vuckovic MG, Huang P, Zaversnik C, Liu CS, Gibson CE, Wheeler MR, Obrochta KM, Min JH, Herber CB, Thompson AC, Shah ID, Gordon SP, Hellerstein MK, Napoli JL. RDH1 suppresses adiposity by promoting brown adipose adaptation to fasting and re-feeding. Cell Mol Life Sci 2019; 76:2425-2447. [PMID: 30788515 PMCID: PMC6531335 DOI: 10.1007/s00018-019-03046-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 02/07/2019] [Accepted: 02/11/2019] [Indexed: 12/26/2022]
Abstract
RDH1 is one of the several enzymes that catalyze the first of the two reactions to convert retinol into all-trans-retinoic acid (atRA). Here, we show that Rdh1-null mice fed a low-fat diet gain more weight as adiposity (17% males, 13% females) than wild-type mice by 20 weeks old, despite neither consuming more calories nor decreasing activity. Glucose intolerance and insulin resistance develop following increased adiposity. Despite the increase in white fat pads, epididymal white adipose does not express Rdh1, nor does muscle. Brown adipose tissue (BAT) and liver express Rdh1 at relatively high levels compared to other tissues. Rdh1 ablation lowered body temperatures during ambient conditions. Given the decreased body temperature, we focused on BAT. A lack of differences in BAT adipogenic gene expression between Rdh1-null mice and wild-type mice, including Pparg, Prdm16, Zfp516 and Zfp521, indicated that the phenotype was not driven by brown adipose hyperplasia. Rather, Rdh1 ablation eliminated the increase in BAT atRA that occurs after re-feeding. This disruption of atRA homeostasis increased fatty acid uptake, but attenuated lipolysis in primary brown adipocytes, resulting in increased lipid content and larger lipid droplets. Rdh1 ablation also decreased mitochondrial proteins, including CYCS and UCP1, the mitochondria oxygen consumption rate, and disrupted the mitochondria membrane potential, further reflecting impaired BAT function, resulting in both BAT and white adipose hypertrophy. RNAseq revealed dysregulation of 424 BAT genes in null mice, which segregated predominantly into differences after fasting vs after re-feeding. Exceptions were Rbp4 and Gbp2b, which increased during both dietary conditions. Rbp4 encodes the serum retinol-binding protein-an insulin desensitizer. Gbp2b encodes a GTPase. Because Gbp2b increased several hundred-fold, we overexpressed it in brown adipocytes. This caused a shift to larger lipid droplets, suggesting that GBP2b affects signaling downstream of the β-adrenergic receptor during basal thermogenesis. Thus, Rdh1-generated atRA in BAT regulates multiple genes that promote BAT adaptation to whole-body energy status, such as fasting and re-feeding. These gene expression changes promote optimum mitochondria function and thermogenesis, limiting adiposity. Attenuation of adiposity and insulin resistance suggests that RDH1 mitigates metabolic syndrome.
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Affiliation(s)
- Charles R Krois
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
- Department of Chemistry and Geology, Minnesota State University, 241 Ford Hall, Mankato, MN, 56001, USA
| | - Marta G Vuckovic
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
| | - Priscilla Huang
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
- Arizona College of Osteopathic Medicine, Midwestern University, 19555 North 59th Avenue, Glendale, AZ, 85308, USA
| | - Claire Zaversnik
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
- AgroSup Dijon, 26 Bd Petitjean, 21000, Dijon, France
| | - Conan S Liu
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
- Sidney Kimmel Medical College, 1025 Walnut Street, Philadelphia, PA, 19104, USA
| | - Candice E Gibson
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
| | - Madelyn R Wheeler
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
- UC Davis School of Medicine, 4102 Sherman Way, Sacramento, CA, 95817, USA
| | - Kristin M Obrochta
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
- Biomarin Pharmaceutical Inc., 105 Digital Drive, Novato, CA, 94949, USA
| | - Jin H Min
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
- Nova Southeastern University, 3301 College Avenue, Fort Lauderdale, FL, 33314, USA
| | - Candice B Herber
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
- University of California, San Francisco, Rock Hall 281, 1550 4th Street, San Francisco, CA, 94158, USA
| | - Airlia C Thompson
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
- Stanford University, Lorry Lokey Building Room 164, 337 Campus Drive, Stanford, CA, 94305-5020, USA
| | - Ishan D Shah
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
- Keck School of Medicine, University of Southern California, 1975 Zonal Avenue, Keith Administration (KAM) 100, Los Angeles, CA, 90089-9020, USA
| | - Sean P Gordon
- DOE Joint Genome Institute, 2800 Mitchell Dr # 100, Walnut Creek, CA, 94598, USA
| | - Marc K Hellerstein
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA
| | - Joseph L Napoli
- Graduate Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 119 Morgan Hall, Berkeley, CA, 94720-3104, USA.
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Nouws J, Fitch M, Mata M, Santoro N, Galuppo B, Kursawe R, Narayan D, Vash-Margita A, Pierpont B, Shulman GI, Hellerstein M, Caprio S. Altered In Vivo Lipid Fluxes and Cell Dynamics in Subcutaneous Adipose Tissues Are Associated With the Unfavorable Pattern of Fat Distribution in Obese Adolescent Girls. Diabetes 2019; 68:1168-1177. [PMID: 30936147 PMCID: PMC6610014 DOI: 10.2337/db18-1162] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 03/24/2019] [Indexed: 12/20/2022]
Abstract
Patterns of abdominal fat distribution (for example, a high vs. low visceral adipose tissue [VAT]/[VAT + subcutaneous adipose tissue (SAT)] ratio), independent of obesity, during adolescence carry a high risk for insulin resistance and type 2 diabetes. Longitudinal follow-up of a cohort of obese adolescents has recently revealed that a high ratio (high VAT/[VAT + SAT]) is a major determinant of fatty liver and metabolic impairment over time, with these effects being more pronounced in girls than in boys. To unravel the underlying metabolic alterations associated with the unfavorable VAT/(VAT + SAT) phenotype, we used the 2H2O labeling method to measure the turnover of adipose lipids and cells in the subcutaneous abdominal and gluteal/femoral adipose tissue (SAT) of weight-stable obese adolescent girls with a similar level of obesity but discordant VAT/(VAT + SAT) ratios. Girls with the unfavorable (high VAT/[VAT + SAT]) phenotype exhibited higher in vivo rates of triglyceride (TG) turnover (representing both lipolysis and synthesis at steady state), without significant differences in de novo lipogenesis in both abdominal and gluteal depots, compared with obese girls with the favorable phenotype. Moreover, mature adipocytes had higher turnover, with no difference in stromal vascular cell proliferation in both depots in the metabolically unfavorable phenotype. The higher TG turnover rates were significantly correlated with higher intrahepatic fat stores. These findings are contrary to the hypothesis that impaired capacity to deposit TGs or proliferation of new mature adipocytes are potential mechanisms for ectopic fat distribution in this setting. In summary, these results suggest that increased turnover of TGs (lipolysis) and of mature adipocytes in both abdominal and gluteal SAT may contribute to metabolic impairment and the development of fatty liver, even at this very early stage of disease.
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Affiliation(s)
- Jessica Nouws
- Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Mark Fitch
- Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, CA
| | - Mariana Mata
- Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Nicola Santoro
- Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Brittany Galuppo
- Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Romy Kursawe
- Diabetes and Obesity, The Jackson Laboratory, Farmington, CT
| | - Deepak Narayan
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Yale University School of Medicine, New Haven, CT
| | - Alla Vash-Margita
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT
| | - Bridget Pierpont
- Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Gerald I Shulman
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT
| | - Marc Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, CA
| | - Sonia Caprio
- Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
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30
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González-Granillo M, Savva C, Li X, Fitch M, Pedrelli M, Hellerstein M, Parini P, Korach-André M, Gustafsson JÅ. ERβ activation in obesity improves whole body metabolism via adipose tissue function and enhanced mitochondria biogenesis. Mol Cell Endocrinol 2019; 479:147-158. [PMID: 30342056 DOI: 10.1016/j.mce.2018.10.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 08/13/2018] [Accepted: 10/07/2018] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Estrogens play a key role in the distribution of adipose tissue and have their action by binding to both estrogen receptors (ER), α and β. Although ERβ has a role in the energy metabolism, limited data of the physiological mechanism and metabolic response involved in the pharmacological activation of ERβ is available. METHODS For clinical relevance, non-ovariectomized female mice were subjected to high fat diet together with pharmacological (DIP - 4-(2-(3,5-dimethylisoxazol-4-yl)-1H-indol-3-yl)phenol) interventions to ERβ selective activation. The physiological mechanism was assessed in vivo by magnetic resonance imaging and spectroscopy, and oral glucose and intraperitoneal insulin tolerance test before and after DIP treatment. Liver and adipose tissue metabolic response was measured in HFD + vehicle and HFD + DIP by stable isotope, RNA sequencing and protein content. RESULTS HFD-fed females treated with DIP had a tissue-specific response towards ERβ selective activation. The metabolic profile showed an improved fasting glucose level, insulin sensitivity and reduced liver steatosis. CONCLUSIONS Our data demonstrate that selective activation of ERβ exerts a tissue-specific activity which promotes a beneficial effect on whole body metabolic response to obesity.
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Affiliation(s)
- Marcela González-Granillo
- Department of Medicine, Metabolism Unit and KI/AZ Integrated CardioMetabolic Center (ICMC), Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden; Department of Biosciences and Nutrition Huddinge, Karolinska Institutet, Sweden.
| | - Christina Savva
- Department of Medicine, Metabolism Unit and KI/AZ Integrated CardioMetabolic Center (ICMC), Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden; Department of Biosciences and Nutrition Huddinge, Karolinska Institutet, Sweden
| | - Xidan Li
- Department of Medicine, Metabolism Unit and KI/AZ Integrated CardioMetabolic Center (ICMC), Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Mark Fitch
- Department of Nutritional Sciences & Toxicology, University of California, Berkeley, USA
| | - Matteo Pedrelli
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Sweden
| | - Marc Hellerstein
- Department of Nutritional Sciences & Toxicology, University of California, Berkeley, USA
| | - Paolo Parini
- Department of Medicine and Department of Laboratory Medicine, Karolinska Institutet, Sweden
| | - Marion Korach-André
- Department of Medicine, Metabolism Unit and KI/AZ Integrated CardioMetabolic Center (ICMC), Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden; Department of Biosciences and Nutrition Huddinge, Karolinska Institutet, Sweden.
| | - Jan-Åke Gustafsson
- Department of Biosciences and Nutrition Huddinge, Karolinska Institutet, Sweden; Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signalling, University of Houston, Houston, TX, USA
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31
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White U, Ravussin E. Dynamics of adipose tissue turnover in human metabolic health and disease. Diabetologia 2019; 62:17-23. [PMID: 30267179 PMCID: PMC6476187 DOI: 10.1007/s00125-018-4732-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 07/25/2018] [Indexed: 12/17/2022]
Abstract
White adipose tissue is a highly plastic organ and is an important regulator of whole-body metabolism and energy balance. The magnitude of adipose tissue mass is determined by dynamic changes in the synthesis and breakdown (i.e. turnover) of adipocytes and triacylglycerols (TGs). Obesity is a disorder characterised by excessive adiposity and is a risk factor for diseases, including the metabolic syndrome and type 2 diabetes. Adipose tissue expansion is necessary to accommodate chronic excess energy intake and is characterised by enlargement of existing adipocytes (hypertrophy) and by increase in pre-adipocyte and adipocyte numbers (hyperplasia). Evidence suggests that the manner of subcutaneous adipose expansion can influence metabolic health, as impaired adipogenesis, namely restricted hyperplasia, may lead to ectopic lipid deposition in the liver and skeletal muscle, contributing to the pathogenesis of obesity-related disorders. Despite the plausible role of adipose turnover in human health and pathology, little is known about the in vivo kinetics of adipose tissue components (both adipose cells and TGs). This is due, in part, to the slow turnover rate of adipose tissue and the complexity of directly labelling pathway precursors. This review provides a brief summary of findings derived from in vitro techniques, as well as an overview of two in vivo methods that are being implemented to assess the turnover of adipose cells and TGs. Finally, the role of adipose tissue turnover in metabolic health and disease is discussed.
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Affiliation(s)
- Ursula White
- Physiology of Human Adipose Tissue Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, 70808, USA.
| | - Eric Ravussin
- Human Translational Physiology Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
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32
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Chen Y, Berejnaia O, Liu J, Wang SP, Daurio NA, Yin W, Mayoral R, Petrov A, Kasumov T, Zhang GF, Previs SF, Kelley DE, McLaren DG. Quantifying ceramide kinetics in vivo using stable isotope tracers and LC-MS/MS. Am J Physiol Endocrinol Metab 2018; 315:E416-E424. [PMID: 29509438 DOI: 10.1152/ajpendo.00457.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Numerous studies have implicated dyslipidemia as a key factor in mediating insulin resistance. Ceramides have received special attention since their levels are inversely associated with normal insulin signaling and positively associated with factors that are involved in cardiometabolic disease. Despite the growing literature surrounding ceramide biology, there are limited data regarding the activity of ceramide synthesis and turnover in vivo. Herein, we demonstrate the ability to measure ceramide kinetics by coupling the administration of [2H]water with LC-MS/MS analyses. As a "proof-of-concept" we determined the effect of a diet-induced alteration on ceramide flux; studies also examined the effect of myriocin (a known inhibitor of serine palmitoyltransferase, the first step in sphingosine biosynthesis). Our data suggest that one can estimate ceramide synthesis and draw conclusions regarding the source of fatty acids; we discuss caveats in regards to method development in this area.
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Affiliation(s)
- Ying Chen
- MRL, Merck & Co., Inc., Kenilworth, New Jersey
| | | | - Jinqi Liu
- MRL, Merck & Co., Inc., Kenilworth, New Jersey
| | | | | | - Wu Yin
- MRL, Merck & Co., Inc., Kenilworth, New Jersey
| | | | | | - Takhar Kasumov
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio
| | - Guo-Fang Zhang
- Division of Endocrinology, Metabolism and Nutrition, Duke Molecular Physiology Institute, and Department of Medicine, Duke University , Durham, North Carolina
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33
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White UA, Fitch MD, Beyl RA, Hellerstein MK, Ravussin E. Racial differences in in vivo adipose lipid kinetics in humans. J Lipid Res 2018; 59:1738-1744. [PMID: 29910190 DOI: 10.1194/jlr.p082628] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 05/16/2018] [Indexed: 11/20/2022] Open
Abstract
The storage of lipids in the form of triglycerides (TGs) and the de novo synthesis (lipogenesis) of fatty acids from nonlipid precursors [de novo lipogenesis (DNL)] are important functions of adipose tissue (AT) that influence whole-body metabolism. Yet, few studies have reported in vivo estimates of adipose lipid kinetics in humans. Fifty-two women with obesity (27 African-American and 25 Caucasian; 29.7 ± 5.5 years; BMI 32.2 ± 2.8 kg/m2; 44.3 ± 4.0% body fat) were enrolled in the study. In vivo synthesis (or replacement) of TGs (fTG) as well as the synthesis of the fatty acid, palmitate [a measure of adipose DNL (fDNL)], were assessed using an 8 week incorporation of deuterium into lipids (glycerol and palmitate moieties of TGs) in subcutaneous abdominal (scABD) and subcutaneous femoral (scFEM) AT. We report, for the first time, significant race differences in both TG synthesis and absolute DNL, with Caucasians having higher fTG and fDNL as compared with African-Americans. The DNL contribution to newly synthesized TG (corrected fDNL) was not different between races. Interestingly, our findings also show that the scFEM adipose depot had higher TG replacement rates relative to the scABD. Finally, the replacement rate of TG (fTG) was negatively correlated with changes in body weight over the 8 week labeling period. Our results provide the first evidence that in vivo TG replacement (synthesis and breakdown) rates differ by ethnicity. In addition, TG turnover varies by depot location in humans, implying an increased capacity for TG storage and higher lipolytic activity in the scFEM AT.
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Affiliation(s)
- Ursula A White
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA
| | - Mark D Fitch
- University of California at Berkeley, Berkeley, CA
| | - Robbie A Beyl
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA
| | | | - Eric Ravussin
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA.
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34
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Goh B, Kim J, Seo S, Kim TY. High-Throughput Measurement of Lipid Turnover Rates Using Partial Metabolic Heavy Water Labeling. Anal Chem 2018; 90:6509-6518. [DOI: 10.1021/acs.analchem.7b05428] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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35
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Murphy CH, Shankaran M, Churchward-Venne TA, Mitchell CJ, Kolar NM, Burke LM, Hawley JA, Kassis A, Karagounis LG, Li K, King C, Hellerstein M, Phillips SM. Effect of resistance training and protein intake pattern on myofibrillar protein synthesis and proteome kinetics in older men in energy restriction. J Physiol 2018. [PMID: 29532476 DOI: 10.1113/jp275246] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
KEY POINTS Strategies to enhance the loss of fat while preserving muscle mass during energy restriction are of great importance to prevent sarcopenia in overweight older adults. We show for the first time that the integrated rate of synthesis of numerous individual contractile, cytosolic and mitochondrial skeletal muscle proteins was increased by resistance training (RT) and unaffected by dietary protein intake pattern during energy restriction in free-living, obese older men. We observed a correlation between the synthetic rates of skeletal muscle-derived proteins obtained in serum (creatine kinase M-type, carbonic anhydrase 3) and the synthetic rates of proteins obtained via muscle sampling; and that the synthesis rates of these proteins in serum revealed the stimulatory effects of RT. These results have ramifications for understanding the influence of RT on skeletal muscle and are consistent with the role of RT in maintaining muscle protein synthesis and potentially supporting muscle mass preservation during weight loss. ABSTRACT We determined how the pattern of protein intake and resistance training (RT) influenced longer-term (2 weeks) integrated myofibrillar protein synthesis (MyoPS) during energy restriction (ER). MyoPS and proteome kinetics were measured during 2 weeks of ER alone and 2 weeks of ER plus RT (ER + RT) in overweight/obese older men. Participants were randomized to consume dietary protein in a balanced (BAL: 25% daily protein per meal × 4 meals) or skewed (SKEW: 7:17:72:4% daily protein per meal) pattern (n = 10 per group). Participants ingested deuterated water during the consecutive 2-week periods, and skeletal muscle biopsies and serum were obtained at the beginning and conclusion of ER and ER + RT. Bulk MyoPS (i.e. synthesis of the myofibrillar protein sub-fraction) and the synthetic rates of numerous individual skeletal muscle proteins were quantified. Bulk MyoPS was not affected by protein distribution during ER or ER + RT (ER: BAL = 1.24 ± 0.31%/day, SKEW = 1.26 ± 0.37%/day; ER + RT: BAL = 1.64 ± 0.48%/day, SKEW = 1.52 ± 0.66%/day) but was ∼26% higher during ER + RT than during ER (P = 0.023). The synthetic rates of 175 of 190 contractile, cytosolic and mitochondrial skeletal muscle proteins, as well as synthesis of muscle-derived proteins measured in serum, creatine kinase M-type (CK-M) and carbonic anhydrase 3 (CA-3), were higher during ER + RT than during ER (P < 0.05). In addition, the synthetic rates of CK-M and CA-3 measured in serum correlated with the synthetic rates of proteins obtained via muscle sampling (P < 0.05). This study provides novel data on the skeletal muscle adaptations to RT and dietary protein distribution.
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Affiliation(s)
| | - Mahalakshmi Shankaran
- KineMed, Inc., Emeryville, CA, USA.,Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
| | | | | | | | - Louise M Burke
- Department of Sports Nutrition, Australian Institute of Sport, Canberra, Australia
| | - John A Hawley
- Exercise and Nutrition Research Group, Mary MacKillop Institute for Health Research, Australian Catholic University, Victoria, Australia.,Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, UK
| | - Amira Kassis
- Nestlé Research Center, Nestec Ltd, Lausanne, Switzerland
| | | | - Kelvin Li
- KineMed, Inc., Emeryville, CA, USA.,Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
| | | | - Marc Hellerstein
- KineMed, Inc., Emeryville, CA, USA.,Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
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36
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Wilkinson DJ. Historical and contemporary stable isotope tracer approaches to studying mammalian protein metabolism. MASS SPECTROMETRY REVIEWS 2018; 37:57-80. [PMID: 27182900 PMCID: PMC5763415 DOI: 10.1002/mas.21507] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 04/22/2016] [Indexed: 06/05/2023]
Abstract
Over a century ago, Frederick Soddy provided the first evidence for the existence of isotopes; elements that occupy the same position in the periodic table are essentially chemically identical but differ in mass due to a different number of neutrons within the atomic nucleus. Allied to the discovery of isotopes was the development of some of the first forms of mass spectrometers, driven forward by the Nobel laureates JJ Thomson and FW Aston, enabling the accurate separation, identification, and quantification of the relative abundance of these isotopes. As a result, within a few years, the number of known isotopes both stable and radioactive had greatly increased and there are now over 300 stable or radioisotopes presently known. Unknown at the time, however, was the potential utility of these isotopes within biological disciplines, it was soon discovered that these stable isotopes, particularly those of carbon (13 C), nitrogen (15 N), oxygen (18 O), and hydrogen (2 H) could be chemically introduced into organic compounds, such as fatty acids, amino acids, and sugars, and used to "trace" the metabolic fate of these compounds within biological systems. From this important breakthrough, the age of the isotope tracer was born. Over the following 80 yrs, stable isotopes would become a vital tool in not only the biological sciences, but also areas as diverse as forensics, geology, and art. This progress has been almost exclusively driven through the development of new and innovative mass spectrometry equipment from IRMS to GC-MS to LC-MS, which has allowed for the accurate quantitation of isotopic abundance within samples of complex matrices. This historical review details the development of stable isotope tracers as metabolic tools, with particular reference to their use in monitoring protein metabolism, highlighting the unique array of tools that are now available for the investigation of protein metabolism in vivo at a whole body down to a single protein level. Importantly, it will detail how this development has been closely aligned to the technological development within the area of mass spectrometry. Without the dedicated development provided by these mass spectrometrists over the past century, the use of stable isotope tracers within the field of protein metabolism would not be as widely applied as it is today, this relationship will no doubt continue to flourish in the future and stable isotope tracers will maintain their importance as a tool within the biological sciences for many years to come. © 2016 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc. Mass Spec Rev.
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Affiliation(s)
- Daniel James Wilkinson
- MRC‐ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular PhysiologyUniversity of Nottingham, Royal Derby Hospital CentreDerbyUnited Kingdom
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37
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Iqbal F, Baker WS, Khan MI, Thukuntla S, McKinney KH, Abate N, Tuvdendorj D. Current and future therapies for addressing the effects of inflammation on HDL cholesterol metabolism. Br J Pharmacol 2017; 174:3986-4006. [PMID: 28326542 PMCID: PMC5660004 DOI: 10.1111/bph.13743] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/16/2017] [Accepted: 02/02/2017] [Indexed: 12/11/2022] Open
Abstract
Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Inflammatory processes arising from metabolic abnormalities are known to precipitate the development of CVD. Several metabolic and inflammatory markers have been proposed for predicting the progression of CVD, including high density lipoprotein cholesterol (HDL-C). For ~50 years, HDL-C has been considered as the atheroprotective 'good' cholesterol because of its strong inverse association with the progression of CVD. Thus, interventions to increase the concentration of HDL-C have been successfully tested in animals; however, clinical trials were unable to confirm the cardiovascular benefits of pharmaceutical interventions aimed at increasing HDL-C levels. Based on these data, the significance of HDL-C in the prevention of CVD has been called into question. Fundamental in vitro and animal studies suggest that HDL-C functionality, rather than HDL-C concentration, is important for the CVD-preventive qualities of HDL-C. Our current review of the literature positively demonstrates the negative impact of systemic and tissue (i.e. adipose tissue) inflammation in the healthy metabolism and function of HDL-C. Our survey indicates that HDL-C may be a good marker of adipose tissue health, independently of its atheroprotective associations. We summarize the current findings on the use of anti-inflammatory drugs to either prevent HDL-C clearance or improve the function and production of HDL-C particles. It is evident that the therapeutic agents currently available may not provide the optimal strategy for altering HDL-C metabolism and function, and thus, further research is required to supplement this mechanistic approach for preventing the progression of CVD. LINKED ARTICLES This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.
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Affiliation(s)
- Fatima Iqbal
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Wendy S Baker
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Madiha I Khan
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Shwetha Thukuntla
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Kevin H McKinney
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Nicola Abate
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
| | - Demidmaa Tuvdendorj
- Division of Endocrinology, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTXUSA
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38
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Wang L, Zhang T, Wang L, Cai Y, Zhong X, He X, Hu L, Tian S, Wu M, Hui L, Zhang H, Gao P. Fatty acid synthesis is critical for stem cell pluripotency via promoting mitochondrial fission. EMBO J 2017; 36:1330-1347. [PMID: 28377463 DOI: 10.15252/embj.201695417] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 02/22/2017] [Accepted: 02/28/2017] [Indexed: 12/17/2022] Open
Abstract
Pluripotent stem cells are known to display distinct metabolic phenotypes than their somatic counterparts. While accumulating studies are focused on the roles of glucose and amino acid metabolism in facilitating pluripotency, little is known regarding the role of lipid metabolism in regulation of stem cell activities. Here, we show that fatty acid (FA) synthesis activation is critical for stem cell pluripotency. Our initial observations demonstrated enhanced lipogenesis in pluripotent cells and during cellular reprogramming. Further analysis indicated that de novo FA synthesis controls cellular reprogramming and embryonic stem cell pluripotency through mitochondrial fission. Mechanistically, we found that de novo FA synthesis regulated by the lipogenic enzyme ACC1 leads to the enhanced mitochondrial fission via (i) consumption of AcCoA which affects acetylation-mediated FIS1 ubiquitin-proteasome degradation and (ii) generation of lipid products that drive the mitochondrial dynamic equilibrium toward fission. Moreover, we demonstrated that the effect of Acc1 on cellular reprogramming via mitochondrial fission also exists in human iPSC induction. In summary, our study reveals a critical involvement of the FA synthesis pathway in promoting ESC pluripotency and iPSC formation via regulating mitochondrial fission.
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Affiliation(s)
- Lihua Wang
- CAS Key Laboratory of Innate Immunity and Chronic Disease, Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, China
| | - Tong Zhang
- CAS Key Laboratory of Innate Immunity and Chronic Disease, Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, China
| | - Lin Wang
- CAS Key Laboratory of Innate Immunity and Chronic Disease, Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, China
| | - Yongping Cai
- Department of Pathology, School of Medicine, Anhui Medical University, Hefei, China
| | - Xiuying Zhong
- CAS Key Laboratory of Innate Immunity and Chronic Disease, Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, China
| | - Xiaoping He
- CAS Key Laboratory of Innate Immunity and Chronic Disease, Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, China
| | - Lan Hu
- CAS Key Laboratory of Innate Immunity and Chronic Disease, Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, China
| | - Shengya Tian
- CAS Key Laboratory of Innate Immunity and Chronic Disease, Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, China
| | - Mian Wu
- CAS Key Laboratory of Innate Immunity and Chronic Disease, Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, China
| | - Lijian Hui
- Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy for Sciences, Shanghai, China
| | - Huafeng Zhang
- CAS Key Laboratory of Innate Immunity and Chronic Disease, Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, China
| | - Ping Gao
- CAS Key Laboratory of Innate Immunity and Chronic Disease, Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, China
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Guillermier C, Fazeli PK, Kim S, Lun M, Zuflacht JP, Milian J, Lee H, Francois-Saint-Cyr H, Horreard F, Larson D, Rosen ED, Lee RT, Lechene CP, Steinhauser ML. Imaging mass spectrometry demonstrates age-related decline in human adipose plasticity. JCI Insight 2017; 2:e90349. [PMID: 28289709 DOI: 10.1172/jci.insight.90349] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Quantification of stable isotope tracers has revealed the dynamic state of living tissues. A new form of imaging mass spectrometry quantifies isotope ratios in domains much smaller than a cubic micron, enabling measurement of cell turnover and metabolism with stable isotope tracers at the single-cell level with a methodology we refer to as multi-isotope imaging mass spectrometry. In a first-in-human study, we utilize stable isotope tracers of DNA synthesis and de novo lipogenesis to prospectively measure cell birth and adipocyte lipid turnover. In a study of healthy adults, we elucidate an age-dependent decline in new adipocyte generation and adipocyte lipid turnover. A linear regression model suggests that the aging effect could be mediated by a decline in insulin-like growth factor-1 (IGF-1). This study therefore establishes a method for measurement of cell turnover and metabolism in humans with subcellular resolution while implicating the growth hormone/IGF-1 axis in adipose tissue aging.
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Affiliation(s)
- Christelle Guillermier
- Department of Medicine, Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Center for NanoImaging, Brigham and Women's Hospital, Cambridge, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| | - Pouneh K Fazeli
- Harvard Medical School, Boston, Massachusetts, USA.,Department of Medicine, Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Soomin Kim
- Department of Medicine, Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Mingyue Lun
- Department of Medicine, Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Jonah P Zuflacht
- Department of Medicine, Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Jessica Milian
- Department of Medicine, Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Hang Lee
- Harvard Medical School, Boston, Massachusetts, USA.,Biostatistics Center, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | | | | | - Evan D Rosen
- Harvard Medical School, Boston, Massachusetts, USA.,Department of Medicine, Division of Endocrinology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Richard T Lee
- Harvard Medical School, Boston, Massachusetts, USA.,Department of Medicine, Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.,Harvard Stem Cell Institute and.,Department of Stem Cell and Regenerative Medicine, Harvard University, Cambridge, Massachusetts, USA
| | - Claude P Lechene
- Department of Medicine, Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Center for NanoImaging, Brigham and Women's Hospital, Cambridge, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew L Steinhauser
- Department of Medicine, Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Center for NanoImaging, Brigham and Women's Hospital, Cambridge, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA.,Department of Medicine, Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.,Harvard Stem Cell Institute and
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40
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Analysis of Mammalian Cell Proliferation and Macromolecule Synthesis Using Deuterated Water and Gas Chromatography-Mass Spectrometry. Metabolites 2016; 6:metabo6040034. [PMID: 27754354 PMCID: PMC5192440 DOI: 10.3390/metabo6040034] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 10/10/2016] [Accepted: 10/10/2016] [Indexed: 11/16/2022] Open
Abstract
Deuterated water (²H₂O), a stable isotopic tracer, provides a convenient and reliable way to label multiple cellular biomass components (macromolecules), thus permitting the calculation of their synthesis rates. Here, we have combined ²H₂O labelling, GC-MS analysis and a novel cell fractionation method to extract multiple biomass components (DNA, protein and lipids) from the one biological sample, thus permitting the simultaneous measurement of DNA (cell proliferation), protein and lipid synthesis rates. We have used this approach to characterize the turnover rates and metabolism of a panel of mammalian cells in vitro (muscle C2C12 and colon cancer cell lines). Our data show that in actively-proliferating cells, biomass synthesis rates are strongly linked to the rate of cell division. Furthermore, in both proliferating and non-proliferating cells, it is the lipid pool that undergoes the most rapid turnover when compared to DNA and protein. Finally, our data in human colon cancer cell lines reveal a marked heterogeneity in the reliance on the de novo lipogenic pathway, with the cells being dependent on both 'self-made' and exogenously-derived fatty acid.
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41
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Wilkinson DJ, Brook MS, Smith K, Atherton PJ. Stable isotope tracers and exercise physiology: past, present and future. J Physiol 2016; 595:2873-2882. [PMID: 27610950 DOI: 10.1113/jp272277] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/23/2016] [Indexed: 12/16/2022] Open
Abstract
Stable isotope tracers have been invaluable assets in physiological research for over 80 years. The application of substrate-specific stable isotope tracers has permitted exquisite insight into amino acid, fatty-acid and carbohydrate metabolic regulation (i.e. incorporation, flux, and oxidation, in a tissue-specific and whole-body fashion) in health, disease and response to acute and chronic exercise. Yet, despite many breakthroughs, there are limitations to 'substrate-specific' stable isotope tracers, which limit physiological insight, e.g. the need for intravenous infusions and restriction to short-term studies (hours) in controlled laboratory settings. In recent years significant interest has developed in alternative stable isotope tracer techniques that overcome these limitations, in particular deuterium oxide (D2 O or heavy water). The unique properties of this tracer mean that through oral administration, the turnover and flux through a number of different substrates (muscle proteins, lipids, glucose, DNA (satellite cells)) can be monitored simultaneously and flexibly (hours/weeks/months) without the need for restrictive experimental control. This makes it uniquely suited for the study of 'real world' human exercise physiology (amongst many other applications). Moreover, using D2 O permits evaluation of turnover of plasma and muscle proteins (e.g. dynamic proteomics) in addition to metabolomics (e.g. fluxomics) to seek molecular underpinnings, e.g. of exercise adaptation. Here, we provide insight into the role of stable isotope tracers, from substrate-specific to novel D2 O approaches, in facilitating our understanding of metabolism. Further novel potential applications of stable isotope tracers are also discussed in the context of integration with the snowballing field of 'omic' technologies.
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Affiliation(s)
- Daniel J Wilkinson
- MRC-ARUK Centre for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - Matthew S Brook
- MRC-ARUK Centre for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - Kenneth Smith
- MRC-ARUK Centre for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - Philip J Atherton
- MRC-ARUK Centre for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
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42
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Srivastava A, Kowalski GM, Callahan DL, Meikle PJ, Creek DJ. Strategies for Extending Metabolomics Studies with Stable Isotope Labelling and Fluxomics. Metabolites 2016; 6:metabo6040032. [PMID: 27706078 PMCID: PMC5192438 DOI: 10.3390/metabo6040032] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 09/21/2016] [Accepted: 09/28/2016] [Indexed: 12/13/2022] Open
Abstract
This is a perspective from the peer session on stable isotope labelling and fluxomics at the Australian & New Zealand Metabolomics Conference (ANZMET) held from 30 March to 1 April 2016 at La Trobe University, Melbourne, Australia. This report summarizes the key points raised in the peer session which focused on the advantages of using stable isotopes in modern metabolomics and the challenges in conducting flux analyses. The session highlighted the utility of stable isotope labelling in generating reference standards for metabolite identification, absolute quantification, and in the measurement of the dynamic activity of metabolic pathways. The advantages and disadvantages of different approaches of fluxomics analyses including flux balance analysis, metabolic flux analysis and kinetic flux profiling were also discussed along with the use of stable isotope labelling in in vivo dynamic metabolomics. A number of crucial technical considerations for designing experiments and analyzing data with stable isotope labelling were discussed which included replication, instrumentation, methods of labelling, tracer dilution and data analysis. This report reflects the current viewpoint on the use of stable isotope labelling in metabolomics experiments, identifying it as a great tool with the potential to improve biological interpretation of metabolomics data in a number of ways.
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Affiliation(s)
- Anubhav Srivastava
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Melbourne, Victoria, Australia.
| | - Greg M Kowalski
- Institute for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood 3125, Victoria, Australia.
| | - Damien L Callahan
- Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Burwood 3125, Victoria, Australia.
| | - Peter J Meikle
- Baker IDI Heart and Diabetes Institute, Melbourne 3004, Victoria, Australia.
| | - Darren J Creek
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Melbourne, Victoria, Australia.
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43
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Li L, Zhang GF, Lee K, Lopez R, Previs SF, Willard B, McCullough A, Kasumov T. A Western diet induced NAFLD in LDLR(-/)(-) mice is associated with reduced hepatic glutathione synthesis. Free Radic Biol Med 2016; 96:13-21. [PMID: 27036364 PMCID: PMC5297627 DOI: 10.1016/j.freeradbiomed.2016.03.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/24/2016] [Accepted: 03/25/2016] [Indexed: 12/11/2022]
Abstract
Oxidative stress plays a key role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Glutathione is the major anti-oxidant involved in cellular oxidative defense, however there are currently no simple non-invasive methods for assessing hepatic glutathione metabolism in patients with NAFLD. As a primary source of plasma glutathione, liver plays an important role in interorgan glutathione homeostasis. In this study, we have tested the hypothesis that measurements of plasma glutathione turnover could be used to assess the hepatic glutathione metabolism in LDLR(-/)(-) mice, a mouse model of diet-induced NAFLD. Mice were fed a standard low fat diet (LFD) or a high fat diet containing cholesterol (a Western type diet (WD)). The kinetics of hepatic and plasma glutathione were quantified using the (2)H2O metabolic labeling approach. Our results show that a WD leads to reduced fractional synthesis rates (FSR) of hepatic (25%/h in LFD vs. 18%/h in WD, P<0.05) and plasma glutathione (43%/h in LFD vs. 21%/h in WD, P<0.05), without any significant effect on their absolute production rates (PRs). WD-induced concordant changes in both hepatic and plasma glutathione turnover suggest that the plasma glutathione turnover measurements could be used to assess hepatic glutathione metabolism. The safety, simplicity, and low cost of the (2)H2O-based glutathione turnover approach suggest that this method has the potential for non-invasive probing of hepatic glutathione metabolism in patients with NAFLD and other diseases.
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Affiliation(s)
- Ling Li
- Department of Research Core Services, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Guo-Fang Zhang
- Department of Nutrition, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Kwangwon Lee
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH 44272, USA
| | - Rocio Lopez
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Stephen F Previs
- Merck Research Laboratories, 2000 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Belinda Willard
- Department of Research Core Services, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Arthur McCullough
- Department of Hepatology and Gastroenterology, Digestive Disease Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Takhar Kasumov
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH 44272, USA; Department of Hepatology and Gastroenterology, Digestive Disease Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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44
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In vivo triglyceride synthesis in subcutaneous adipose tissue of humans correlates with plasma HDL parameters. Atherosclerosis 2016; 251:147-152. [PMID: 27323227 DOI: 10.1016/j.atherosclerosis.2016.06.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 06/07/2016] [Accepted: 06/10/2016] [Indexed: 11/20/2022]
Abstract
BACKGROUNDS AND AIMS Low concentrations of plasma HDL-C are associated with the development of atherosclerotic cardiovascular diseases and type 2 diabetes. Here we aimed to explore the relationship between the in vivo fractional synthesis of triglycerides (fTG) in subcutaneous (s.q.) abdominal adipose tissue (AT), HDL-C concentrations and HDL particle size composition in non-diabetic humans. METHODS The fTG in s.q. abdominal AT was measured in 16 non-diabetic volunteers (7 women, 9 men; Age: 49 ± 20 years; BMI: 31 ± 5 kg/m; Fasting Plasma Glucose: 90 ± 10 mg/dl) after (2)H2O labeling. HDL-C concentration and subclasses, large (L-HDL), intermediate (I-HDL) and small (S-HDL) were measured. RESULTS Linear regression analyses demonstrated significant associations of fTG with plasma concentration of HDL-C (r = 0.625,p = 0.009) and percent contribution of L-HDL (r = 0.798,p < 0.001), I-HDL (r = -0.765,p < 0.001) and S-HDL (r = -0.629, p = 0.009). When analyses were performed by gender, the associations remained significant in women (HDL-C: r = 0.822,p = 0.023; L-HDL: r = 0.892,p = 0.007; I-HDL: r = -0.927,p = 0.003) but not men. CONCLUSIONS Our study demonstrated an in vivo association between subcutaneous abdominal adipose tissue lipid dynamics and HDL parameters in humans, but this was true for women not men. Positive association with L-HDL and negative with I-HDL suggest that subcutaneous abdominal adipose tissue lipid dynamics may play an important role in production of mature functional HDL particles. Further studies evaluating the mechanism responsible for these associations and the observed gender differences are important and warranted to identify potential novel targets of intervention to increase the production of atheroprotective subclasses of HDL-Cs and thus decreasing the risks of development of atherosclerotic conditions.
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45
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Kowalski GM, Hamley S, Selathurai A, Kloehn J, De Souza DP, O'Callaghan S, Nijagal B, Tull DL, McConville MJ, Bruce CR. Reversing diet-induced metabolic dysregulation by diet switching leads to altered hepatic de novo lipogenesis and glycerolipid synthesis. Sci Rep 2016; 6:27541. [PMID: 27273128 PMCID: PMC4895138 DOI: 10.1038/srep27541] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/18/2016] [Indexed: 02/02/2023] Open
Abstract
In humans, low-energy diets rapidly reduce hepatic fat and improve/normalise glycemic control. Due to difficulties in obtaining human liver, little is known about changes to the lipid species and pathway fluxes that occur under these conditions. Using a combination of stable isotope, and targeted metabolomic approaches we investigated the acute (7-9 days) hepatic effects of switching high-fat high-sucrose diet (HFD) fed obese mice back to a chow diet. Upon the switch, energy intake was reduced, resulting in reductions of fat mass and hepatic triacyl- and diacylglycerol. However, these parameters were still elevated compared to chow fed mice, thus representing an intermediate phenotype. Nonetheless, glucose intolerance and hyperinsulinemia were completely normalized. The diet reversal resulted in marked reductions in hepatic de novo lipogenesis when compared to the chow and HFD groups. Compared with HFD, glycerolipid synthesis was reduced in the reversal animals, however it remained elevated above that of chow controls, indicating that despite experiencing a net loss in lipid stores, the liver was still actively esterifying available fatty acids at rates higher than that in chow control mice. This effect likely promotes the re-esterification of excess free fatty acids released from the breakdown of adipose depots during the weight loss period.
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Affiliation(s)
- Greg M Kowalski
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
| | - Steven Hamley
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
| | - Ahrathy Selathurai
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
| | - Joachim Kloehn
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, Parkville, Australia
| | - David P De Souza
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, Parkville, Australia
| | - Sean O'Callaghan
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, Parkville, Australia
| | - Brunda Nijagal
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, Parkville, Australia
| | - Dedreia L Tull
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, Parkville, Australia
| | - Malcolm J McConville
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, Parkville, Australia
| | - Clinton R Bruce
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
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46
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An LC-MRM method for measuring intestinal triglyceride assembly using an oral stable isotope-labeled fat challenge. Bioanalysis 2016; 8:1265-77. [DOI: 10.4155/bio-2016-0024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Aim: A traditional oral fatty acid challenge assesses absorption of triacylglycerol (TG) into the periphery through the intestines, but cannot distinguish the composition or source of fatty acid in the TG. Stable isotope-labeled tracers combined with LC-MRM can be used to identify and distinguish TG synthesized with dietary and stored fatty acids. Results: Concentrations of three abundant TGs (52:2, 54:3 and 54:4) were monitored for incorporation of one or two 2H11-oleate molecules per TG. This method was subjected to routine assay validation and meets typical requirements for an assay to be used to support clinical studies. Conclusion: Calculations for the fractional appearance rate of TG in plasma are presented along with the intracellular enterocyte precursor pool for 12 study participants.
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47
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Wang CY, Shie SS, Wen MS, Hung KC, Hsieh IC, Yeh TS, Wu D. Loss of FTO in adipose tissue decreases Angptl4 translation and alters triglyceride metabolism. Sci Signal 2015; 8:ra127. [PMID: 26671148 DOI: 10.1126/scisignal.aab3357] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A common variant of the FTO (fat mass- and obesity-associated) gene is a risk factor for obesity. We found that mice with an adipocyte-specific deletion of FTO gained more weight than control mice on a high-fat diet. Analysis of mice lacking FTO in adipocytes fed a normal diet or adipocytes from these mice revealed alterations in triglyceride metabolism that would be expected to favor increased fatty acid storage by adipose tissue. Mice lacking FTO in adipocytes showed increased serum triglyceride breakdown and clearance, which was associated with lower serum triglyceride concentrations. In addition, lipolysis in response to β-adrenergic stimulation was decreased in adipocytes and ex vivo adipose explants from the mutant mice. FTO is a nucleic acid demethylase that removes N(6)-methyladenosine (m(6)A) from mRNAs. We found that FTO bound to Angptl4, which encodes an adipokine that stimulates intracellular lipolysis in adipocytes. Unexpectedly, the adipose tissue of fasted or fed mice lacking FTO in adipocytes had greater Angptl4 mRNA abundance. However, after high-fat feeding, the mutant mice had less Angptl4 protein and more m(6)A-modified Angptl4 than control mice, suggesting that lack of FTO prevented the translation of Angptl4. Injection of Angptl4-encoding adenovirus into mice lacking FTO in adipocytes restored serum triglyceride concentrations and lipolysis to values similar to those in control mice and abolished excessive weight gain from a high-fat diet. These results reveal that FTO regulates fatty acid mobilization in adipocytes and thus body weight in part through posttranscriptional regulation of Angptl4.
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Affiliation(s)
- Chao-Yung Wang
- Department of Cardiology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan 33302, Taiwan.
| | - Shian-Sen Shie
- Department of Infectious Diseases, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
| | - Ming-Shien Wen
- Department of Cardiology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
| | - Kuo-Chun Hung
- Department of Cardiology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
| | - I-Chang Hsieh
- Department of Cardiology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
| | - Ta-Sen Yeh
- Department of General Surgery, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
| | - Delon Wu
- Department of Cardiology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
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Allen DK, Bates PD, Tjellström H. Tracking the metabolic pulse of plant lipid production with isotopic labeling and flux analyses: Past, present and future. Prog Lipid Res 2015; 58:97-120. [PMID: 25773881 DOI: 10.1016/j.plipres.2015.02.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 01/30/2015] [Accepted: 02/11/2015] [Indexed: 11/25/2022]
Abstract
Metabolism is comprised of networks of chemical transformations, organized into integrated biochemical pathways that are the basis of cellular operation, and function to sustain life. Metabolism, and thus life, is not static. The rate of metabolites transitioning through biochemical pathways (i.e., flux) determines cellular phenotypes, and is constantly changing in response to genetic or environmental perturbations. Each change evokes a response in metabolic pathway flow, and the quantification of fluxes under varied conditions helps to elucidate major and minor routes, and regulatory aspects of metabolism. To measure fluxes requires experimental methods that assess the movements and transformations of metabolites without creating artifacts. Isotopic labeling fills this role and is a long-standing experimental approach to identify pathways and quantify their metabolic relevance in different tissues or under different conditions. The application of labeling techniques to plant science is however far from reaching it potential. In light of advances in genetics and molecular biology that provide a means to alter metabolism, and given recent improvements in instrumentation, computational tools and available isotopes, the use of isotopic labeling to probe metabolism is becoming more and more powerful. We review the principal analytical methods for isotopic labeling with a focus on seminal studies of pathways and fluxes in lipid metabolism and carbon partitioning through central metabolism. Central carbon metabolic steps are directly linked to lipid production by serving to generate the precursors for fatty acid biosynthesis and lipid assembly. Additionally some of the ideas for labeling techniques that may be most applicable for lipid metabolism in the future were originally developed to investigate other aspects of central metabolism. We conclude by describing recent advances that will play an important future role in quantifying flux and metabolic operation in plant tissues.
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Affiliation(s)
- Doug K Allen
- United States Department of Agriculture, Agricultural Research Service, 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.
| | - Philip D Bates
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS 39406, United States
| | - Henrik Tjellström
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, United States; Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, United States
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49
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Frikke-Schmidt H, Pedersen TÅ, Fledelius C, Olsen GS, Bouman SD, Fitch M, Hellerstein M. Treatment of diabetic rats with insulin or a synthetic insulin receptor agonist peptide leads to divergent metabolic responses. Diabetes 2015; 64:1057-66. [PMID: 25315006 DOI: 10.2337/db14-0914] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In addition to lowering of blood glucose, treatment with insulin also induces lipid synthesis and storage. Patients with type 2 diabetes often suffer from lipid-related comorbidities including dyslipidemia, obesity, and fatty liver disease. We examined here in two separate studies changes in lipid dynamics in Zucker diabetic fatty (ZDF) rats, in response to 7 days of treatment with either insulin or the insulin receptor agonist peptide S597. In concert with blood glucose normalization, the treated rats displayed large increases in hepatic de novo lipid synthesis and deposition of newly synthesized lipids in adipose tissue depots, accompanied by weight gain and expansion of adipose depots. In both treatment groups, heavy water labeling revealed that after 2 h (study A), de novo lipogenesis was responsible for 80% of newly stored hepatic triglyceride (TG)-palmitate, and after 5 days (study B), ∼60% of newly deposited TG-palmitate in adipose tissues originated from this pathway. Interestingly, in both studies, treatment with the insulin mimetic peptide resulted in significantly lower blood TG levels, plasma TG production rates, and hepatic de novo synthesized fatty acid in plasma TG compared with insulin. There were no differences in plasma TG turnover (clearance rate) in response to either treatment, consistent with differential actions on the liver. These results show that in ZDF rats, treatment with a synthetic insulin-receptor-activating peptide or with insulin to lower blood glucose is accompanied by different effects on hepatic lipid anabolism and blood TG profiles.
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Affiliation(s)
- Henriette Frikke-Schmidt
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA Department of Insulin Biology, Novo Nordisk, Maaloev, Denmark
| | | | | | - Grith S Olsen
- Department of Insulin Biology, Novo Nordisk, Maaloev, Denmark
| | - Stephan D Bouman
- Department of Insulin Pharmacology, Novo Nordisk, Maaloev, Denmark
| | - Mark Fitch
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA
| | - Marc Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA KineMed, Inc., Emeryville, CA
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Lee JJ, Lambert JE, Hovhannisyan Y, Ramos-Roman MA, Trombold JR, Wagner DA, Parks EJ. Palmitoleic acid is elevated in fatty liver disease and reflects hepatic lipogenesis. Am J Clin Nutr 2015; 101:34-43. [PMID: 25527748 PMCID: PMC4266891 DOI: 10.3945/ajcn.114.092262] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Biochemical evidence has linked the coordinate control of fatty acid (FA) synthesis with the activity of stearoyl-CoA desaturase-1 (SCD1). The ratio of 16:1n-7 to 16:0 [SCD1₁₆] in plasma triacylglycerol FA has been used as an index to reflect liver SCD1₁₆ activity and has been proposed as a biomarker of FA synthesis, although this use has not been validated by comparison with isotopically measured de novo lipogenesis (DNL(Meas)). OBJECTIVE We investigated plasma lipid 16:1n-7 and FA indexes of elongation and desaturation in relation to lipogenesis. DESIGN In this cross-sectional investigation of metabolism, 24 overweight adults, who were likely to have elevated DNL, consumed D2O for 10 d and had liver fat (LF) measured by magnetic resonance spectroscopy. Very-low-density lipoprotein (VLDL)-triacylglycerols and plasma free FA [nonesterified fatty acids (NEFAs)] were analyzed by using gas chromatography for the FA composition (molar percentage) and gas chromatography-mass spectrometry and gas chromatography-combustion isotope ratio mass spectrometry for deuterium enrichment. RESULTS In all subjects, VLDL-triacylglycerol 16:1n-7 was significantly (P < 0.01) related to DNL(Meas) (r = 0.56), liver fat (r = 0.53), and adipose insulin resistance (r = 0.56); similar positive relations were shown with the SCD1₁₆ index, and the pattern in NEFAs echoed that of VLDL-triacylglycerols. Compared with subjects with low LF (3.1 ± 2.7%; n = 11), subjects with high LF (18.4 ± 3.6%; n = 13) exhibited a 45% higher VLDL-triacylglycerol 16:1n-7 molar percentage (P < 0.01), 16% of subjects had lower 18:2n-6 (P = 0.01), and 27% of subjects had higher DNL as assessed by using a published DNL index (ratio of 16:0 to 18:2n-6; P = 0.03), which was isotopically confirmed by DNL(Meas) (increased 2.5-fold; P < 0.01). Compared with 16:0 in the diet, the low amount of dietary 16:1n-7 in VLDL-triacylglycerols corresponded to a stronger signal of elevated DNL. CONCLUSION The current data provide support for the use of the VLDL-triacylglycerol 16:1n-7 molar percentage as a biomarker for elevated liver fat when isotope use is not feasible; however, larger-scale confirmatory studies are needed.
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Affiliation(s)
- Joseph J Lee
- From the Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX (JJL, JEL, YH, and JRT); the Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (MAR-R); Metabolic Solutions Inc., Nashua, NH (DAW); and the Department of Nutrition and Exercise Physiology, School of Medicine, University of Missouri, Columbia, MO (EJP)
| | - Jennifer E Lambert
- From the Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX (JJL, JEL, YH, and JRT); the Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (MAR-R); Metabolic Solutions Inc., Nashua, NH (DAW); and the Department of Nutrition and Exercise Physiology, School of Medicine, University of Missouri, Columbia, MO (EJP)
| | - Yelena Hovhannisyan
- From the Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX (JJL, JEL, YH, and JRT); the Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (MAR-R); Metabolic Solutions Inc., Nashua, NH (DAW); and the Department of Nutrition and Exercise Physiology, School of Medicine, University of Missouri, Columbia, MO (EJP)
| | - Maria A Ramos-Roman
- From the Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX (JJL, JEL, YH, and JRT); the Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (MAR-R); Metabolic Solutions Inc., Nashua, NH (DAW); and the Department of Nutrition and Exercise Physiology, School of Medicine, University of Missouri, Columbia, MO (EJP)
| | - Justin R Trombold
- From the Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX (JJL, JEL, YH, and JRT); the Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (MAR-R); Metabolic Solutions Inc., Nashua, NH (DAW); and the Department of Nutrition and Exercise Physiology, School of Medicine, University of Missouri, Columbia, MO (EJP)
| | - David A Wagner
- From the Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX (JJL, JEL, YH, and JRT); the Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (MAR-R); Metabolic Solutions Inc., Nashua, NH (DAW); and the Department of Nutrition and Exercise Physiology, School of Medicine, University of Missouri, Columbia, MO (EJP)
| | - Elizabeth J Parks
- From the Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX (JJL, JEL, YH, and JRT); the Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (MAR-R); Metabolic Solutions Inc., Nashua, NH (DAW); and the Department of Nutrition and Exercise Physiology, School of Medicine, University of Missouri, Columbia, MO (EJP)
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