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Milioto A, Corica G, Nista F, Wildemberg LEA, Rossi F, Bignotti B, Gadelha MR, Ferone D, Tagliafico AS, Gatto F. Skeletal Muscle Evaluation in Patients With Acromegaly. J Endocr Soc 2024; 8:bvae032. [PMID: 38434516 PMCID: PMC10907006 DOI: 10.1210/jendso/bvae032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Indexed: 03/05/2024] Open
Abstract
Context Patients with acromegaly are characterized by chronic exposure to high growth hormone (GH) and insulin-like growth factor-1 levels, known for their anabolic effect on skeletal muscle. Therefore, an increased skeletal muscle mass could be hypothesized in these individuals. Herein, we have performed a systematic revision of published evidence regarding skeletal muscle mass, quality, and performance in patients with acromegaly. Evidence Acquisition A systematic review of the literature in the PubMed database up to September 1, 2023, was conducted with the following query: acromegaly AND ("muscle mass" OR "skeletal muscle"). We excluded studies that did not compare different disease states or used nonradiological methods for the skeletal muscle analyses, except for bioelectrical impedance analysis. Evidence Synthesis Fifteen studies met the inclusion criteria. A total of 360 patients were evaluated for skeletal muscle mass, 122 for muscle fatty atrophy, and 192 for muscle performance. No clear evidence of increased skeletal muscle mass in patients with active disease compared to control or healthy individuals emerged. As for skeletal muscle quality, we observed a trend toward higher fatty infiltration among patients with acromegaly compared to healthy participants. Likewise, patients with active disease showed consistently worse physical performance compared to control or healthy individuals. Conclusion Skeletal muscle in acromegaly has lower quality and performance compared to that of healthy individuals. The small number of published studies and multiple confounding factors (eg, use of different radiological techniques) contributed to mixed results, especially regarding skeletal muscle mass. Well-designed prospective studies are needed to investigate skeletal muscle mass in patients with acromegaly.
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Affiliation(s)
- Angelo Milioto
- Endocrinology Unit, Department of Internal Medicine and Medical Specialties (DIMI), University of Genoa, Genoa 16138, Italy
| | - Giuliana Corica
- Endocrinology Unit, Department of Internal Medicine and Medical Specialties (DIMI), University of Genoa, Genoa 16138, Italy
| | - Federica Nista
- Endocrinology Unit, Department of Internal Medicine and Medical Specialties (DIMI), University of Genoa, Genoa 16138, Italy
| | - Luiz Eduardo Armondi Wildemberg
- Neuroendocrinology Research Center/Endocrinology Division, Medical School and Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-913, Brazil
| | - Federica Rossi
- Department of Radiology, Ospedale Santa Corona, Pietra Ligure 17027, Italy
| | - Bianca Bignotti
- Department of Radiology, IRCCS Ospedale Policlinico San Martino, Genoa 16139, Italy
| | - Mônica R Gadelha
- Neuroendocrinology Research Center/Endocrinology Division, Medical School and Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-913, Brazil
| | - Diego Ferone
- Endocrinology Unit, Department of Internal Medicine and Medical Specialties (DIMI), University of Genoa, Genoa 16138, Italy
- Endocrinology Unit, IRCCS Ospedale Policlinico San Martino, Genoa 16139, Italy
| | - Alberto Stefano Tagliafico
- Department of Health Sciences (DISSAL), University of Genoa, Genoa 16138, Italy
- Department of Radiology, IRCCS Ospedale Policlinico San Martino, Genoa 16139, Italy
| | - Federico Gatto
- Endocrinology Unit, IRCCS Ospedale Policlinico San Martino, Genoa 16139, Italy
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Pînzariu O, Georgescu CE. Metabolomics in acromegaly: a systematic review. J Investig Med 2023:10815589231169452. [PMID: 37139720 DOI: 10.1177/10815589231169452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The therapeutic response heterogeneity in acromegaly persists, despite the medical-surgical advances of recent years. Thus, personalized medicine implementation, which focuses on each patient, is justified. Metabolomics would decipher the molecular mechanisms underlying the therapeutic response heterogeneity. Identification of altered metabolic pathways would open new horizons in the therapeutic management of acromegaly. This research aimed to evaluate the metabolomic profile in acromegaly and metabolomics' contributions to understanding disease pathogenesis. A systematic review was carried out by querying four electronic databases and evaluating patients with acromegaly through metabolomic techniques. In all, 21 studies containing 362 patients were eligible. Choline, the ubiquitous metabolite identified in growth hormone (GH)-secreting pituitary adenomas (Pas) by in vivo magnetic resonance spectroscopy (MRS), negatively correlated with somatostatin receptors type 2 expression and positively correlated with magnetic resonance imaging T2 signal and Ki-67 index. Moreover, elevated choline and choline/creatine ratio differentiated between sparsely and densely granulated GH-secreting PAs. MRS detected low hepatic lipid content in active acromegaly, which increased after disease control. The panel of metabolites of acromegaly deciphered by mass spectrometry (MS)-based techniques mainly included amino acids (especially branched-chain amino acids and taurine), glyceric acid, and lipids. The most altered pathways in acromegaly were the metabolism of glucose (particularly the downregulation of the pentose phosphate pathway), linoleic acid, sphingolipids, glycerophospholipids, arginine/proline, and taurine/hypotaurine. Matrix-assisted laser desorption/ionization coupled with MS imaging confirmed the functional nature of GH-secreting PAs and accurately discriminated PAs from healthy pituitary tissue.
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Affiliation(s)
- Oana Pînzariu
- Department of Endocrinology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Carmen Emanuela Georgescu
- Department of Endocrinology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
- Endocrinology Clinic, Cluj County Emergency Clinical Hospital, Cluj-Napoca, Romania
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3
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Kuker AP, Shen W, Jin Z, Chen J, Bruce JN, Freda PU. Long-term Outcome of Body Composition, Ectopic Lipid, and Insulin Resistance Changes With Surgical Treatment of Acromegaly. J Endocr Soc 2023; 7:bvad028. [PMID: 36922916 PMCID: PMC10008673 DOI: 10.1210/jendso/bvad028] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Indexed: 02/25/2023] Open
Abstract
Context Acromegaly presents a unique pattern of lower adiposity and insulin resistance in active disease but reduction in insulin resistance despite a rise in adiposity after surgery. Depot-specific adipose tissue masses and ectopic lipid are important predictors of insulin resistance in other populations, but whether they are in acromegaly is unknown. Long-term persistence of body composition changes after surgery is unknown. Objective To determine how depot-specific body composition and ectopic lipid relate to insulin resistance in active acromegaly and whether their changes with surgery are sustained long-term. Methods Cross-sectional study in patients with active acromegaly and longitudinal study in newly diagnosed patients studied before and in long-term follow-up, 3 (1-8) years (median, range), after surgery. Seventy-one patients with active acromegaly studied cross-sectionally and 28 with newly diagnosed acromegaly studied longitudinally. Main outcome measures were visceral (VAT), subcutaneous (SAT), and intermuscular adipose tissue masses by whole-body magnetic resonance imaging; intrahepatic lipid (IHL) by proton magnetic resonance spectroscopy; insulin resistance measures derived from fasting; and oral glucose tolerance test insulin and glucose levels. Results SAT and insulin-like growth factor 1 level, but not VAT or IHL, were independent predictors of insulin resistance in active acromegaly. VAT, SAT, and IHL gains were sustained long-term after surgery. VAT mass rise with surgery correlated inversely with rise in QUICKI while SAT rise correlated with fall in the Homeostatic Model Assessment score. Conclusion SAT and disease activity are important predictors of insulin resistance in active acromegaly. Adiposity gains are sustained long-term after surgical treatment and impact on the accompanying improvement in insulin resistance.
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Affiliation(s)
- Adriana P Kuker
- Department of Medicine, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY 10032, USA
| | - Wei Shen
- Department of Pediatrics, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY 10032, USA
| | - Zhezhen Jin
- Biostatistics, Mailman School of Public Health, Columbia University, New York, NY, 10032, USA
| | - Jun Chen
- Department of Pediatrics, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY 10032, USA
| | - Jeffrey N Bruce
- Department of Neurosurgery, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY, 10032, USA
| | - Pamela U Freda
- Department of Medicine, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY 10032, USA
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4
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Abstract
Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) are essential to normal growth, metabolism, and body composition, but in acromegaly, excesses of these hormones strikingly alter them. In recent years, the use of modern methodologies to assess body composition in patients with acromegaly has revealed novel aspects of the acromegaly phenotype. In particular, acromegaly presents a unique pattern of body composition changes in the setting of insulin resistance that we propose herein to be considered an acromegaly-specific lipodystrophy. The lipodystrophy, initiated by a distinctive GH-driven adipose tissue dysregulation, features insulin resistance in the setting of reduced visceral adipose tissue (VAT) mass and intra-hepatic lipid (IHL) but with lipid redistribution, resulting in ectopic lipid deposition in muscle. With recovery of the lipodystrophy, adipose tissue mass, especially that of VAT and IHL, rises, but insulin resistance is lessened. Abnormalities of adipose tissue adipokines may play a role in the disordered adipose tissue metabolism and insulin resistance of the lipodystrophy. The orexigenic hormone ghrelin and peptide Agouti-related peptide may also be affected by active acromegaly as well as variably by acromegaly therapies, which may contribute to the lipodystrophy. Understanding the pathophysiology of the lipodystrophy and how acromegaly therapies differentially reverse its features may be important to optimizing the long-term outcome for patients with this disease. This perspective describes evidence in support of this acromegaly lipodystrophy model and its relevance to acromegaly pathophysiology and the treatment of patients with acromegaly.
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Affiliation(s)
- Pamela U. Freda
- Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
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5
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Von-Hafe M, Borges-Canha M, Vale C, Leite AR, Sérgio Neves J, Carvalho D, Leite-Moreira A. Nonalcoholic Fatty Liver Disease and Endocrine Axes—A Scoping Review. Metabolites 2022; 12:metabo12040298. [PMID: 35448486 PMCID: PMC9026925 DOI: 10.3390/metabo12040298] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/20/2022] [Accepted: 03/27/2022] [Indexed: 02/07/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease. NAFLD often occurs associated with endocrinopathies. Evidence suggests that endocrine dysfunction may play an important role in NAFLD development, progression, and severity. Our work aimed to explore and summarize the crosstalk between the liver and different endocrine organs, their hormones, and dysfunctions. For instance, our results show that hyperprolactinemia, hypercortisolemia, and polycystic ovary syndrome seem to worsen NAFLD’s pathway. Hypothyroidism and low growth hormone levels also may contribute to NAFLD’s progression, and a bidirectional association between hypercortisolism and hypogonadism and the NAFLD pathway looks likely, given the current evidence. Therefore, we concluded that it appears likely that there is a link between several endocrine disorders and NAFLD other than the typically known type 2 diabetes mellitus and metabolic syndrome (MS). Nevertheless, there is controversial and insufficient evidence in this area of knowledge.
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Affiliation(s)
- Madalena Von-Hafe
- Departamento de Cirurgia e Fisiologia, Faculdade de Medicina da Universidade do Porto, 4200-319 Porto, Portugal; (M.V.-H.); (C.V.); (A.R.L.); (J.S.N.); (A.L.-M.)
| | - Marta Borges-Canha
- Departamento de Cirurgia e Fisiologia, Faculdade de Medicina da Universidade do Porto, 4200-319 Porto, Portugal; (M.V.-H.); (C.V.); (A.R.L.); (J.S.N.); (A.L.-M.)
- Serviço de Endocrinologia, Diabetes e Metabolismo do Centro Hospitalar Universitário de São João, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal;
- Correspondence: ; Tel.: +351-918935390
| | - Catarina Vale
- Departamento de Cirurgia e Fisiologia, Faculdade de Medicina da Universidade do Porto, 4200-319 Porto, Portugal; (M.V.-H.); (C.V.); (A.R.L.); (J.S.N.); (A.L.-M.)
| | - Ana Rita Leite
- Departamento de Cirurgia e Fisiologia, Faculdade de Medicina da Universidade do Porto, 4200-319 Porto, Portugal; (M.V.-H.); (C.V.); (A.R.L.); (J.S.N.); (A.L.-M.)
| | - João Sérgio Neves
- Departamento de Cirurgia e Fisiologia, Faculdade de Medicina da Universidade do Porto, 4200-319 Porto, Portugal; (M.V.-H.); (C.V.); (A.R.L.); (J.S.N.); (A.L.-M.)
- Serviço de Endocrinologia, Diabetes e Metabolismo do Centro Hospitalar Universitário de São João, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal;
| | - Davide Carvalho
- Serviço de Endocrinologia, Diabetes e Metabolismo do Centro Hospitalar Universitário de São João, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal;
- Investigação e Inovação em Saúde (i3s), Faculdade de Medicina da Universidade do Porto, 4200-319 Porto, Portugal
| | - Adelino Leite-Moreira
- Departamento de Cirurgia e Fisiologia, Faculdade de Medicina da Universidade do Porto, 4200-319 Porto, Portugal; (M.V.-H.); (C.V.); (A.R.L.); (J.S.N.); (A.L.-M.)
- Serviço de Cirurgia Cardiotorácica do Centro Hospitalar Universitário de São João, 4200-319 Porto, Portugal
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6
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Kuker AP, Shen W, Jin Z, Singh S, Chen J, Bruce JN, Freda PU. Body Composition Changes with Long-term Pegvisomant Therapy of Acromegaly. J Endocr Soc 2021; 5:bvab004. [PMID: 33553983 PMCID: PMC7853172 DOI: 10.1210/jendso/bvab004] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Indexed: 12/16/2022] Open
Abstract
Context In active acromegaly, the lipolytic and insulin antagonistic effects of growth hormone (GH) excess alter adipose tissue (AT) deposition, reduce body fat, and increase insulin resistance. This pattern reverses with surgical therapy. Pegvisomant treats acromegaly by blocking GH receptor (GHR) signal transduction and lowering insulin-like growth factor 1 (IGF-1) levels. The long-term effects of GHR antagonist treatment of acromegaly on body composition have not been studied. Methods We prospectively studied 21 patients with active acromegaly who were starting pegvisomant. Body composition was examined by whole body magnetic resonance imaging, proton magnetic resonance spectroscopy of liver and muscle and dual-energy x-ray absorptiometry, and endocrine and metabolic markers were measured before and serially during 1.0 to 13.4 years of pegvisomant therapy. The data of patients with acromegaly were compared with predicted and to matched controls. Results Mass of visceral AT (VAT) increased to a peak of 187% (1.56-229%) (P < .001) and subcutaneous AT (SAT) to 109% (–17% to 57%) (P = .04) of baseline. These remained persistently and stably increased, but did not differ from predicted during long-term pegvisomant therapy. Intrahepatic lipid rose from 1.75% to 3.04 % (P = .04). Although lean tissue mass decreased significantly, skeletal muscle (SM) did not change. IGF-1 levels normalized, and homeostasis model assessment insulin resistance and HbA1C were lowered. Conclusion Long-term pegvisomant therapy is accompanied by increases in VAT and SAT mass that do not differ from predicted, stable SM mass and improvements in glucose metabolism. Long-term pegvisomant therapy does not produce a GH deficiency-like pattern of body composition change.
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Affiliation(s)
- Adriana P Kuker
- Department of Medicine, Columbia University, New York, NY, USA
| | - Wei Shen
- Department of Pediatrics, Columbia University, New York, NY, USA.,Institute of Human Nutrition, Columbia University, New York, NY, USA.,Columbia Magnetic Resonance Research Center (CMRRC), Vagelos College of Physicians & Surgeons, Columbia University, New York, NY, USA
| | - Zhezhen Jin
- Columbia University and Biostatistics, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Simran Singh
- Department of Medicine, Columbia University, New York, NY, USA
| | - Jun Chen
- Department of Pediatrics, Columbia University, New York, NY, USA
| | - Jeffrey N Bruce
- Department of Neurosurgery, Columbia University, New York, NY, USA
| | - Pamela U Freda
- Department of Medicine, Columbia University, New York, NY, USA
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7
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GH/IGF-1 Abnormalities and Muscle Impairment: From Basic Research to Clinical Practice. Int J Mol Sci 2021; 22:ijms22010415. [PMID: 33401779 PMCID: PMC7795003 DOI: 10.3390/ijms22010415] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 12/22/2020] [Accepted: 12/28/2020] [Indexed: 12/29/2022] Open
Abstract
The impairment of skeletal muscle function is one of the most debilitating least understood co-morbidity that accompanies acromegaly (ACRO). Despite being one of the major determinants of these patients’ poor quality of life, there is limited evidence related to the underlying mechanisms and treatment options. Although growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels are associated, albeit not indisputable, with the presence and severity of ACRO myopathies the precise effects attributed to increased GH or IGF-1 levels are still unclear. Yet, cell lines and animal models can help us bridge these gaps. This review aims to describe the evidence regarding the role of GH and IGF-1 in muscle anabolism, from the basic to the clinical setting with special emphasis on ACRO. We also pinpoint future perspectives and research lines that should be considered for improving our knowledge in the field.
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8
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Abstract
Acromegaly is characterized by Growth Hormone (GH) and Insulin-like Growth Factor 1 (IGF-1) excess. Uncontrolled acromegaly is associated with a strongly increased risk of cardiovascular disease (CVD), and numerous cardiovascular risk factors remain present after remission. GH and IGF-1 have numerous effects on the immune and cardiovascular system. Since endothelial damage and systemic inflammation are strongly linked to the development of CVD, and have been suggested to be present in both controlled as uncontrolled acromegaly, they may explain the presence of both micro- and macrovascular dysfunction in these patients. In addition, these changes seem to be only partially reversible after remission, as illustrated by the often reported presence of endothelial dysfunction and microvascular damage in controlled acromegaly. Previous studies suggest that insulin resistance, oxidative stress, and endothelial dysfunction are involved in the development of CVD in acromegaly. Not surprisingly, these processes are associated with systemic inflammation and respond to GH/IGF-1 normalizing treatment.
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Affiliation(s)
- Thalijn L C Wolters
- Department of Internal Medicine, Radboud University Medical Center Nijmegen, Geert Grooteplein Zuid 10, 6525, GA, Nijmegen, The Netherlands.
| | - Mihai G Netea
- Department of Internal Medicine, Radboud University Medical Center Nijmegen, Geert Grooteplein Zuid 10, 6525, GA, Nijmegen, The Netherlands
- Department for Genomics & Immunoregulation, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Niels P Riksen
- Department of Internal Medicine, Radboud University Medical Center Nijmegen, Geert Grooteplein Zuid 10, 6525, GA, Nijmegen, The Netherlands
| | - Adrianus R M M Hermus
- Department of Internal Medicine, Radboud University Medical Center Nijmegen, Geert Grooteplein Zuid 10, 6525, GA, Nijmegen, The Netherlands
| | - Romana T Netea-Maier
- Department of Internal Medicine, Radboud University Medical Center Nijmegen, Geert Grooteplein Zuid 10, 6525, GA, Nijmegen, The Netherlands
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9
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Ren J, Sherry AD, Malloy CR. Modular 31 P wideband inversion transfer for integrative analysis of adenosine triphosphate metabolism, T 1 relaxation and molecular dynamics in skeletal muscle at 7T. Magn Reson Med 2019; 81:3440-3452. [PMID: 30793793 DOI: 10.1002/mrm.27686] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/16/2019] [Accepted: 01/18/2019] [Indexed: 12/13/2022]
Abstract
PURPOSE For efficient and integrative analysis of de novo adenosine triphosphate (ATP) synthesis, creatine-kinase-mediated ATP synthesis, T1 relaxation time, and ATP molecular motion dynamics in human skeletal muscle at rest. METHODS Four inversion-transfer modules differing in center inversion frequency were combined to generate amplified magnetization transfer (MT) effects in targeted MT pathways, including Pi ↔ γ-ATP, PCr ↔ γ-ATP, and 31 Pγ(α)ATP ↔ 31 PβATP . MT effects from both forward and reverse exchange kinetic pathways were acquired to reduce potential bias and confounding factors in integrated data analysis. RESULTS Kinetic data collected using 4 wideband inversion modules (8 minutes each) yielded the forward exchange rate constants, kPCr →γ ATP = 0.31 ± 0.05 s-1 and kPi →γ ATP = 0.064 ± 0.012 s-1 , and the reverse exchange rate constants, kγATP→Pi = 0.034 ± 0.006 s-1 and kγATP→PCr = 1.37 ± 0.22 s-1 , respectively. The cross-relaxation rate constant, σγ(α) ↔ βATP was -0.20 ± 0.03 s-1 , corresponding to ATP rotational correlation time τc of 0.8 ± 0.1 × 10-7 seconds. The intrinsic T1 relaxation times were Pi (9.2 ± 1.4 seconds), PCr (6.2 ± 0.4 seconds), γ-ATP (1.8 ± 0.1 seconds), α-ATP (1.4 ± 0.1 seconds), and β-ATP (1.1 ± 0.1 seconds). Muscle ATP T1 values were found to be significantly longer than those previously measured in the brain using a similar method. CONCLUSION A combination of multiple inversion transfer modules provides a comprehensive and integrated analysis of ATP metabolism and molecular motion dynamics. This relatively fast technique could be potentially useful for studying metabolic disorders in skeletal muscle.
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Affiliation(s)
- Jimin Ren
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - A Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Chemistry, University of Texas at Dallas, Richardson, Texas
| | - Craig R Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas.,VA North Texas Health Care System, Dallas, Texas
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Bakshi I, Suryana E, Small L, Quek LE, Brandon AE, Turner N, Cooney GJ. Fructose bisphosphatase 2 overexpression increases glucose uptake in skeletal muscle. J Endocrinol 2018; 237:101-111. [PMID: 29507044 DOI: 10.1530/joe-17-0555] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 03/05/2018] [Indexed: 12/31/2022]
Abstract
Skeletal muscle is a major tissue for glucose metabolism and can store glucose as glycogen, convert glucose to lactate via glycolysis and fully oxidise glucose to CO2 Muscle has a limited capacity for gluconeogenesis but can convert lactate and alanine to glycogen. Gluconeogenesis requires FBP2, a muscle-specific form of fructose bisphosphatase that converts fructose-1,6-bisphosphate (F-1,6-bisP) to fructose-6-phosphate (F-6-P) opposing the activity of the ATP-consuming enzyme phosphofructokinase (PFK). In mammalian muscle, the activity of PFK is normally 100 times higher than FBP2 and therefore energy wasting cycling between PFK and FBP2 is low. In an attempt to increase substrate cycling between F-6-P and F-1,6-bisP and alter glucose metabolism, we overexpressed FBP2 using a muscle-specific adeno-associated virus (AAV-tMCK-FBP2). AAV was injected into the right tibialis muscle of rats, while the control contralateral left tibialis received a saline injection. Rats were fed a chow or 45% fat diet (HFD) for 5 weeks after which, hyperinsulinaemic-euglycaemic clamps were performed. Infection of the right tibialis with AAV-tMCK-FBP2 increased FBP2 activity 10 fold on average in chow and HFD rats (P < 0.0001). Overexpression of FBP2 significantly increased insulin-stimulated glucose uptake in tibialis of chow animals (control 14.3 ± 1.7; FBP2 17.6 ± 1.6 µmol/min/100 g) and HFD animals (control 9.6 ± 1.1; FBP2 11.2 ± 1.1µmol/min/100 g). The results suggest that increasing the capacity for cycling between F-1,6-bisP and F-6-P can increase the metabolism of glucose by introducing a futile cycle in muscle, but this increase is not sufficient to overcome muscle insulin resistance.
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Affiliation(s)
- Ishita Bakshi
- Diabetes and Metabolism DivisionGarvan Institute, Sydney, New South Wales, Australia
| | - Eurwin Suryana
- Diabetes and Metabolism DivisionGarvan Institute, Sydney, New South Wales, Australia
| | - Lewin Small
- Diabetes and Metabolism DivisionGarvan Institute, Sydney, New South Wales, Australia
| | - Lake-Ee Quek
- School of Mathematics and StatisticsUniversity of Sydney, Charles Perkins Centre, Sydney, New South Wales, Australia
| | - Amanda E Brandon
- Diabetes and Metabolism DivisionGarvan Institute, Sydney, New South Wales, Australia
- Sydney Medical SchoolCharles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Nigel Turner
- Department of PharmacologySchool of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Gregory J Cooney
- Diabetes and Metabolism DivisionGarvan Institute, Sydney, New South Wales, Australia
- Sydney Medical SchoolCharles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
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11
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Metabolic disturbances of non-alcoholic fatty liver resemble the alterations typical for type 2 diabetes. Clin Sci (Lond) 2017; 131:1905-1917. [DOI: 10.1042/cs20170261] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 06/12/2017] [Accepted: 06/15/2017] [Indexed: 01/01/2023]
Abstract
Non-alcoholic fatty liver (NAFL) is an independent risk factor for the development of type 2 diabetes (T2DM). We examined metabolic perturbations in patients with NAFL, patients with T2DM, and control (CON) subjects with normal intrahepatic lipid (IHL) content.A two-step (10 mU/m2 /min; 40 mU/m2/min) hyperinsulinemic–euglycemic clamp was performed in 11 NAFL, 13 T2DM, and 11 CON subjects, all matched for BMI, and aerobic fitness. IHL content was measured using proton magnetic resonance spectroscopy. Because of high IHL content variability in T2DM patients, this group was separated into a high IHL content group (IHL ≥ 5.0%, T2DM+NAFL) and a normal IHL content group (IHL < 5.0%, T2DM-non-NAFL) for further analysis.IHL content was increased in NAFL and T2DM+NAFL subjects (P<0.050 versus CON and T2DM-non-NAFL subjects). Adipose tissue insulin sensitivity index (Adipo-IRi) was higher in NAFL (P<0.050 versus CON and T2DM-non-NAFL subjects) and in T2DM+NAFL subjects (P=0.055 versus CON subjects, P<0.050 versus T2DM-non-NAFL subjects). Suppression of plasma-free fatty acids (P=0.046) was lower in NAFL compared with CON subjects, with intermediate values for T2DM-non-NAFL, and T2DM+NAFL subjects. Suppression of endogenous glucose production (EGP) and insulin-stimulated glucose disposal (ΔRd) was comparable between NAFL, T2DM-non-NAFL, and T2DM+NAFL subjects (all P>0.05), and was lower in comparison with CON subjects (all P<0.01). Metabolic flexibility was lower in T2DM-non-NAFL subjects (P=0.047) and NAFL subjects (P=0.059) compared with CON subjects. Adipo-IRi (r=0.652, P<0.001), hepatic insulin resistance index (HIRi) (r=0.576, P=0.001), and ΔRd (r=−0.653, P<0.001) correlated with IHL content.Individuals with NAFL suffer from metabolic perturbations to a similar degree as T2DM patients. NAFL is an important feature leading to severe insulin resistance and should be viewed as a serious health threat for the development of T2DM. ClinicalTrials.gov: NCT01317576
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Fritsch M, Koliaki C, Livingstone R, Phielix E, Bierwagen A, Meisinger M, Jelenik T, Strassburger K, Zimmermann S, Brockmann K, Wolff C, Hwang JH, Szendroedi J, Roden M. Time course of postprandial hepatic phosphorus metabolites in lean, obese, and type 2 diabetes patients. Am J Clin Nutr 2015; 102:1051-8. [PMID: 26423389 DOI: 10.3945/ajcn.115.107599] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 08/26/2015] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Impaired energy metabolism is a possible mechanism that contributes to insulin resistance and ectopic fat storage. OBJECTIVE We examined whether meal ingestion differently affects hepatic phosphorus metabolites in insulin-sensitive and insulin-resistant humans. DESIGN Young, lean, insulin-sensitive humans (CONs) [mean ± SD body mass index (BMI; in kg/m(2)): 23.2 ± 1.5]; insulin-resistant, glucose-tolerant, obese humans (OBEs) (BMI: 34.3 ± 1.7); and type 2 diabetes patients (T2Ds) (BMI: 32.0 ± 2.4) were studied (n = 10/group). T2Ds (61 ± 7 y old) were older (P < 0.001) than were OBEs (31 ± 7 y old) and CONs (28 ± 3 y old). We quantified hepatic γATP, inorganic phosphate (Pi), and the fat content [hepatocellular lipids (HCLs)] with the use of (31)P/(1)H magnetic resonance spectroscopy before and at 160 and 240 min after a high-caloric mixed meal. In a subset of volunteers, we measured the skeletal muscle oxidative capacity with the use of high-resolution respirometry. Whole-body insulin sensitivity (M value) was assessed with the use of hyperinsulinemic-euglycemic clamps. RESULTS OBEs and T2Ds were similarly insulin resistant (M value: 3.5 ± 1.4 and 1.9 ± 2.5 mg · kg(-1) · min(-1), respectively; P = 0.9) and had 12-fold (P = 0.01) and 17-fold (P = 0.002) higher HCLs, respectively, than those of lean persons. Despite comparable fasting hepatic γATP concentrations, the maximum postprandial increase of γATP was 6-fold higher in OBEs (0.7 ± 0.2 mmol/L; P = 0.03) but only tended to be higher in T2Ds (0.6 ± 0.2 mmol/L; P = 0.09) than in CONs (0.1 ± 0.1 mmol/L). However, in the fasted state, muscle complex I activity was 53% lower (P = 0.01) in T2Ds but not in OBEs (P = 0.15) than in CONs. CONCLUSIONS Young, obese, nondiabetic humans exhibit augmented postprandial hepatic energy metabolism, whereas elderly T2Ds have impaired fasting muscle energy metabolism. These findings support the concept of a differential and tissue-specific regulation of energy metabolism, which can occur independently of insulin resistance. This trial was registered at clinicaltrials.gov as NCT01229059.
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Affiliation(s)
- Maria Fritsch
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Department of Pediatric and Adolescent Medicine, Medical University of Vienna, Vienna, Austria; and
| | - Chrysi Koliaki
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Department of Endocrinology and Diabetology, Medical Faculty, and German Center of Diabetes Research, Partner Düsseldorf, Germany
| | - Roshan Livingstone
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research
| | - Esther Phielix
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research
| | - Alessandra Bierwagen
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, German Center of Diabetes Research, Partner Düsseldorf, Germany
| | - Markus Meisinger
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research
| | - Tomas Jelenik
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, German Center of Diabetes Research, Partner Düsseldorf, Germany
| | - Klaus Strassburger
- Institute for Biometrics and Epidemiology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich-Heine University, Düsseldorf, Germany, German Center of Diabetes Research, Partner Düsseldorf, Germany
| | - Stefanie Zimmermann
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, German Center of Diabetes Research, Partner Düsseldorf, Germany
| | - Katharina Brockmann
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, German Center of Diabetes Research, Partner Düsseldorf, Germany
| | - Christina Wolff
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, German Center of Diabetes Research, Partner Düsseldorf, Germany
| | - Jong-Hee Hwang
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, German Center of Diabetes Research, Partner Düsseldorf, Germany
| | - Julia Szendroedi
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Department of Endocrinology and Diabetology, Medical Faculty, and German Center of Diabetes Research, Partner Düsseldorf, Germany
| | - Michael Roden
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Department of Endocrinology and Diabetology, Medical Faculty, and German Center of Diabetes Research, Partner Düsseldorf, Germany
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Reyes-Vidal CM, Mojahed H, Shen W, Jin Z, Arias-Mendoza F, Fernandez JC, Gallagher D, Bruce JN, Post KD, Freda PU. Adipose Tissue Redistribution and Ectopic Lipid Deposition in Active Acromegaly and Effects of Surgical Treatment. J Clin Endocrinol Metab 2015; 100:2946-55. [PMID: 26037515 PMCID: PMC4524994 DOI: 10.1210/jc.2015-1917] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
CONTEXT GH and IGF-I have important roles in the maintenance of substrate metabolism and body composition. However, when in excess in acromegaly, the lipolytic and insulin antagonistic effects of GH may alter adipose tissue (AT) deposition. OBJECTIVES The purpose of this study was to examine the effect of surgery for acromegaly on AT distribution and ectopic lipid deposition in liver and muscle. DESIGN This was a prospective study before and up to 2 years after pituitary surgery. SETTING The setting was an academic pituitary center. PATIENTS Participants were 23 patients with newly diagnosed, untreated acromegaly. MAIN OUTCOME MEASURES We determined visceral (VAT), subcutaneous (SAT), and intermuscular adipose tissue (IMAT), and skeletal muscle compartments by total-body magnetic resonance imaging, intrahepatic and intramyocellular lipid by proton magnetic resonance spectroscopy, and serum endocrine, metabolic, and cardiovascular risk markers. RESULTS VAT and SAT masses were lower than predicted in active acromegaly, but increased after surgery in male and female subjects along with lowering of GH, IGF-I, and insulin resistance. VAT and SAT increased to a greater extent in men than in women. Skeletal muscle mass decreased in men. IMAT was higher in active acromegaly and decreased in women after surgery. Intrahepatic lipid increased, but intramyocellular lipid did not change after surgery. CONCLUSIONS Acromegaly may present a unique type of lipodystrophy characterized by reduced storage of AT in central depots and a shift of excess lipid to IMAT. After surgery, this pattern partially reverses, but differentially in men and women. These findings have implications for understanding the role of GH in body composition and metabolic risk in acromegaly and other clinical settings of GH use.
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Affiliation(s)
- Carlos M Reyes-Vidal
- Departments of Medicine (C.M.R.-V., W.S., J.C.F., D.G., P.U.F.), Radiology (H.M., F.A.-M.), Biostatistics (Z.J.), and Neurosurgery (J.N.B.), Columbia University, College of Physicians & Surgeons, New York, New York 10032; and Departments of Medicine and Neurosurgery (K.D.P.), Mt. Sinai School of Medicine, New York, New York 10029
| | - Hamed Mojahed
- Departments of Medicine (C.M.R.-V., W.S., J.C.F., D.G., P.U.F.), Radiology (H.M., F.A.-M.), Biostatistics (Z.J.), and Neurosurgery (J.N.B.), Columbia University, College of Physicians & Surgeons, New York, New York 10032; and Departments of Medicine and Neurosurgery (K.D.P.), Mt. Sinai School of Medicine, New York, New York 10029
| | - Wei Shen
- Departments of Medicine (C.M.R.-V., W.S., J.C.F., D.G., P.U.F.), Radiology (H.M., F.A.-M.), Biostatistics (Z.J.), and Neurosurgery (J.N.B.), Columbia University, College of Physicians & Surgeons, New York, New York 10032; and Departments of Medicine and Neurosurgery (K.D.P.), Mt. Sinai School of Medicine, New York, New York 10029
| | - Zhezhen Jin
- Departments of Medicine (C.M.R.-V., W.S., J.C.F., D.G., P.U.F.), Radiology (H.M., F.A.-M.), Biostatistics (Z.J.), and Neurosurgery (J.N.B.), Columbia University, College of Physicians & Surgeons, New York, New York 10032; and Departments of Medicine and Neurosurgery (K.D.P.), Mt. Sinai School of Medicine, New York, New York 10029
| | - Fernando Arias-Mendoza
- Departments of Medicine (C.M.R.-V., W.S., J.C.F., D.G., P.U.F.), Radiology (H.M., F.A.-M.), Biostatistics (Z.J.), and Neurosurgery (J.N.B.), Columbia University, College of Physicians & Surgeons, New York, New York 10032; and Departments of Medicine and Neurosurgery (K.D.P.), Mt. Sinai School of Medicine, New York, New York 10029
| | - Jean Carlos Fernandez
- Departments of Medicine (C.M.R.-V., W.S., J.C.F., D.G., P.U.F.), Radiology (H.M., F.A.-M.), Biostatistics (Z.J.), and Neurosurgery (J.N.B.), Columbia University, College of Physicians & Surgeons, New York, New York 10032; and Departments of Medicine and Neurosurgery (K.D.P.), Mt. Sinai School of Medicine, New York, New York 10029
| | - Dympna Gallagher
- Departments of Medicine (C.M.R.-V., W.S., J.C.F., D.G., P.U.F.), Radiology (H.M., F.A.-M.), Biostatistics (Z.J.), and Neurosurgery (J.N.B.), Columbia University, College of Physicians & Surgeons, New York, New York 10032; and Departments of Medicine and Neurosurgery (K.D.P.), Mt. Sinai School of Medicine, New York, New York 10029
| | - Jeffrey N Bruce
- Departments of Medicine (C.M.R.-V., W.S., J.C.F., D.G., P.U.F.), Radiology (H.M., F.A.-M.), Biostatistics (Z.J.), and Neurosurgery (J.N.B.), Columbia University, College of Physicians & Surgeons, New York, New York 10032; and Departments of Medicine and Neurosurgery (K.D.P.), Mt. Sinai School of Medicine, New York, New York 10029
| | - Kalmon D Post
- Departments of Medicine (C.M.R.-V., W.S., J.C.F., D.G., P.U.F.), Radiology (H.M., F.A.-M.), Biostatistics (Z.J.), and Neurosurgery (J.N.B.), Columbia University, College of Physicians & Surgeons, New York, New York 10032; and Departments of Medicine and Neurosurgery (K.D.P.), Mt. Sinai School of Medicine, New York, New York 10029
| | - Pamela U Freda
- Departments of Medicine (C.M.R.-V., W.S., J.C.F., D.G., P.U.F.), Radiology (H.M., F.A.-M.), Biostatistics (Z.J.), and Neurosurgery (J.N.B.), Columbia University, College of Physicians & Surgeons, New York, New York 10032; and Departments of Medicine and Neurosurgery (K.D.P.), Mt. Sinai School of Medicine, New York, New York 10029
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Das S, Morvan F, Jourde B, Meier V, Kahle P, Brebbia P, Toussaint G, Glass DJ, Fornaro M. ATP citrate lyase improves mitochondrial function in skeletal muscle. Cell Metab 2015; 21:868-76. [PMID: 26039450 DOI: 10.1016/j.cmet.2015.05.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 03/12/2015] [Accepted: 04/29/2015] [Indexed: 12/16/2022]
Abstract
Mitochondrial dysfunction is associated with skeletal muscle pathology, including cachexia, sarcopenia, and the muscular dystrophies. ATP citrate lyase (ACL) is a cytosolic enzyme that catalyzes mitochondria-derived citrate into oxaloacetate and acetyl-CoA. Here we report that activation of ACL in skeletal muscle results in improved mitochondrial function. IGF1 induces activation of ACL in an AKT-dependent fashion. This results in an increase in cardiolipin, thus increasing critical mitochondrial complexes and supercomplex activity, and a resultant increase in oxygen consumption and cellular ATP levels. Conversely, knockdown of ACL in myotubes not only reduces mitochondrial complex I, IV, and V activity but also blocks IGF1-induced increases in oxygen consumption. In vivo, ACL activity is associated with increased ATP. Activation of this IGF1/ACL/cardiolipin pathway combines anabolic signaling with induction of mechanisms needed to provide required ATP.
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Affiliation(s)
- Suman Das
- Novartis Institutes for Biomedical Research, Forum 1, Novartis Campus, 4056 Basel, Switzerland
| | - Frederic Morvan
- Novartis Institutes for Biomedical Research, Forum 1, Novartis Campus, 4056 Basel, Switzerland
| | - Benjamin Jourde
- Novartis Institutes for Biomedical Research, Forum 1, Novartis Campus, 4056 Basel, Switzerland
| | - Viktor Meier
- Novartis Institutes for Biomedical Research, Forum 1, Novartis Campus, 4056 Basel, Switzerland
| | - Peter Kahle
- Novartis Institutes for Biomedical Research, Forum 1, Novartis Campus, 4056 Basel, Switzerland
| | - Pascale Brebbia
- Novartis Institutes for Biomedical Research, Forum 1, Novartis Campus, 4056 Basel, Switzerland
| | - Gauthier Toussaint
- Novartis Institutes for Biomedical Research, Forum 1, Novartis Campus, 4056 Basel, Switzerland
| | - David J Glass
- Novartis Institutes for Biomedical Research, 100 Technology Square, Cambridge, MA 02139, USA.
| | - Mara Fornaro
- Novartis Institutes for Biomedical Research, Forum 1, Novartis Campus, 4056 Basel, Switzerland.
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Hatipoglu E, Arici C, Arslan OS, Dikkaya F, Sultan P, Kadioglu P, Gundogdu S. Corneal endothelial cell density and morphology in patients with acromegaly. Growth Horm IGF Res 2014; 24:260-263. [PMID: 25174811 DOI: 10.1016/j.ghir.2014.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/08/2014] [Accepted: 08/11/2014] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Acromegaly has various impacts on many organs. The ophthalmologic effects of acromegaly have not yet been investigated in detail. The aim of the current study was to evaluate qualitative and quantitative changes in corneal endothelial cells and central corneal thickness (CCT) of the patients with acromegaly. DESIGN In this prospective, cross-sectional study, 128 eyes of 64 patients with acromegaly (female/male=40/24) and 208 eyes of 104 age and gender-matched healthy volunteers (female/male=69/35) were included. Endothelial cell density (ECD), cellular area (CA), coefficient of variation (CV) in cell size, percentage of hexagonal cells, and CCT were measured in patients with acromegaly and in healthy volunteers using the noncontact specular microscopy (SP-3000P: Topcon Corporation, Tokyo, Japan). RESULTS ECD and CA were lower in cases with acromegaly than in controls (ECD in acromegaly: 2615.65 cell/mm(2) and in controls: 2700.35 cell/mm(2); p=0.002. CA in acromegaly: 382.30μm(2) and in controls: 400.30μm(2); p=0.02). In the entire group with acromegaly, the time elapsed since diagnosis was positively correlated with CA and was negatively correlated with ECD (r=+0.39, p=0.001 and r=-0.42, p=0.001). CONCLUSIONS The endothelial layer of the cornea may be under risk of impairment with prolonged disease duration in acromegaly. Consistency of the corneal endothelium should be also sought during long-term follow-up of the cases with acromegaly.
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Affiliation(s)
- Esra Hatipoglu
- Edirne State Hospital, Department of Internal Medicine, Division of Endocrinology and Metabolism, Turkey.
| | - Ceyhun Arici
- Istanbul University, Cerrahpasa Medical School, Department of Ophthalmology, Turkey
| | - Osman Sevki Arslan
- Istanbul University, Cerrahpasa Medical School, Department of Ophthalmology, Turkey
| | - Funda Dikkaya
- Istanbul University, Cerrahpasa Medical School, Department of Ophthalmology, Turkey
| | - Pinar Sultan
- Istanbul University, Cerrahpasa Medical School, Department of Ophthalmology, Turkey
| | - Pinar Kadioglu
- Istanbul University, Cerrahpasa Medical School, Department of Internal Medicine, Division of Endocrinology and Metabolism, Turkey
| | - Sadi Gundogdu
- Istanbul University, Cerrahpasa Medical School, Department of Internal Medicine, Division of Endocrinology and Metabolism, Turkey
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16
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Ectopic lipid storage in non-alcoholic fatty liver disease is not mediated by impaired mitochondrial oxidative capacity in skeletal muscle. Clin Sci (Lond) 2014; 127:655-63. [PMID: 24738611 DOI: 10.1042/cs20130404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD), characterized by lipid deposition within the liver [intrahepatocellular lipid (IHCL)], is associated with insulin resistance and the metabolic syndrome (MS). It has been suggested that impaired skeletal muscle mitochondrial function may contribute to ectopic lipid deposition, and the associated MS, by altering post-prandial energy storage. To test this hypothesis, we performed a cross-sectional study of 17 patients with NAFLD [mean±S.D.; age, 45±11 years; body mass index (BMI), 31.6±3.4 kg/m2] and 18 age- and BMI-matched healthy controls (age, 44±11 years; BMI, 30.5±5.2 kg/m2). We determined body composition by MRI, IHCL and intramyocellular (soleus and tibialis anterior) lipids (IMCLs) by proton magnetic resonance spectroscopy (1H-MRS) and skeletal muscle mitochondrial function by dynamic phosphorus magnetic resonance spectroscopy (31P-MRS) of quadriceps muscle. Although matched for BMI and total adiposity, after statistical adjustment for gender, patients with NAFLD (defined by IHCL ≥ 5.5%) had higher IHCLs (25±16% compared with 2±2%; P<0.0005) and a higher prevalence of the MS (76% compared with 28%) compared with healthy controls. Despite this, the visceral fat/subcutaneous fat ratio, IMCLs and muscle mitochondrial function were similar between the NAFLD and control groups, with no significant difference in the rate constants of post-exercise phosphocreatine (PCr) recovery (1.55±0.4 compared with 1.51±0.4 min-1), a measure of muscle mitochondrial function. In conclusion, impaired muscle mitochondrial function does not seem to underlie ectopic lipid deposition, or the accompanying features of the MS, in patients with NAFLD.
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Winhofer Y, Wolf P, Krššák M, Wolfsberger S, Tura A, Pacini G, Gessl A, Raber W, Kukurova IJ, Kautzky-Willer A, Knosp E, Trattnig S, Krebs M, Luger A. No evidence of ectopic lipid accumulation in the pathophysiology of the acromegalic cardiomyopathy. J Clin Endocrinol Metab 2014; 99:4299-306. [PMID: 25148232 DOI: 10.1210/jc.2014-2242] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT PATIENTS with acromegaly frequently display disturbances of glucose and lipid metabolism, which might contribute to their increased cardiovascular risk. Because insulin resistance and increased lipolysis have been linked to ectopic lipid deposition, altered lipid accumulation in the liver and the myocardium might contribute to metabolic and cardiac complications in these patients. OBJECTIVE The aim of this study was to investigate myocardial (MYCL) and hepatic lipid content (HCL), insulin sensitivity, and cardiac function in active acromegaly and after control of GH excess through transsphenoidal surgery. PATIENTS Ten patients with newly diagnosed acromegaly (ACRO_active) were compared with 12 healthy controls (CON), matched for age, body mass index, and gender. In seven patients GH excess was controlled, and they were compared with their active state. METHODS MYCL and HCL were assessed by (1)H-magnetic resonance spectroscopy, pericardial fat and cardiac function by (1)H-magnetic resonance imaging, and insulin sensitivity and secretion by an oral glucose tolerance test. RESULTS Although MYCL tended to be lower, HCL was significantly lower in ACRO_active compared with CON (HCL: 1.2% ± 1.2% vs 4.3% ± 3.5% of (1)H-magnetic resonance spectroscopy signal, P < .02). Parameters of systolic function and hypertrophy were significantly increased in ACRO_active compared with CON, as were insulin secretion and resistance. After the control of GH excess, HCL and MYCL remained unchanged, but pericardial fat was increased in the patients in whom GH excess was controlled (from 11.6 ± 5.5 to 14.7 ± 6.2 cm(2), P = .02). CONCLUSION Acromegaly represents a unique condition characterized by low myocardial and hepatic lipid content despite decreased insulin sensitivity, hyperinsulinemia, and hyperglycemia. Hence, ectopic lipid accumulation does not appear to contribute to cardiac morbidity, and increased lipid oxidation might counteract ectopic lipid accumulation in GH excess.
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Affiliation(s)
- Yvonne Winhofer
- Department of Internal Medicine III, Division of Endocrinology and Metabolism (Y.W., P.W., M.Krš., A.G., W.R., A.K.-W., M.Kre., A.L.), Department of Biomedical Imaging and Image Guided therapy, Centre of Excellence High-field MR (M.Krš., I.J.K., S.T.), and Department of Neurosurgery (S.W., E.K.), Medical University of Vienna, A-1090 Vienna, Austria; and Institute of Biomedical Engineering (A.T., G.P.), National Research Council, Metabolic Unit, I-35127 Padova, Italy
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Szendroedi J, Kaul K, Kloock L, Straßburger K, Schmid AI, Chmelik M, Kacerovsky M, Kacerovsky-Bielesz G, Prikoszovich T, Brehm A, Krssák M, Gruber S, Krebs M, Kautzky-Willer A, Moser E, Pacini G, Roden M. Lower fasting muscle mitochondrial activity relates to hepatic steatosis in humans. Diabetes Care 2014; 37:468-74. [PMID: 24026561 DOI: 10.2337/dc13-1359] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Muscle insulin resistance has been implicated in the development of steatosis and dyslipidemia by changing the partitioning of postprandial substrate fluxes. Also, insulin resistance may be due to reduced mitochondrial function. We examined the association between mitochondrial activity, insulin sensitivity, and steatosis in a larger human population. RESEARCH DESIGN AND METHODS We analyzed muscle mitochondrial activity from ATP synthase flux (fATP) and ectopic lipids by multinuclei magnetic resonance spectroscopy from 113 volunteers with and without diabetes. Insulin sensitivity was assessed from M values using euglycemic-hyperinsulinemic clamps and/or from oral glucose insulin sensitivity (OGIS) using oral glucose tolerance tests. RESULTS Muscle fATP correlated negatively with hepatic lipid content and HbA1c. After model adjustment for study effects and other confounders, fATP showed a strong negative correlation with hepatic lipid content and a positive correlation with insulin sensitivity and fasting C-peptide. The negative correlation of muscle fATP with age, HbA1c, and plasma free fatty acids was weakened after adjustment. Body mass, muscle lipid contents, plasma lipoproteins, and triglycerides did not associate with fATP. CONCLUSIONS The association of impaired muscle mitochondrial activity with hepatic steatosis supports the concept of a close link between altered muscle and liver energy metabolism as early abnormalities promoting insulin resistance.
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Befroy DE, Rothman DL, Petersen KF, Shulman GI. ³¹P-magnetization transfer magnetic resonance spectroscopy measurements of in vivo metabolism. Diabetes 2012; 61:2669-78. [PMID: 23093656 PMCID: PMC3478545 DOI: 10.2337/db12-0558] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Magnetic resonance spectroscopy offers a broad range of noninvasive analytical methods for investigating metabolism in vivo. Of these, the magnetization-transfer (MT) techniques permit the estimation of the unidirectional fluxes associated with metabolic exchange reactions. Phosphorus (³¹P) MT measurements can be used to examine the bioenergetic reactions of the creatine-kinase system and the ATP synthesis/hydrolysis cycle. Observations from our group and others suggest that the inorganic phosphate (P(i)) → ATP flux in skeletal muscle may be modulated by certain conditions, including aging, insulin resistance, and diabetes, and may reflect inherent alterations in mitochondrial metabolism. However, such effects on the P(i) → ATP flux are not universally observed under conditions in which mitochondrial function, assessed by other techniques, is impaired, and recent articles have raised concerns about the absolute magnitude of the measured reaction rates. As the application of ³¹P-MT techniques becomes more widespread, this article reviews the methodology and outlines our experience with its implementation in a variety of models in vivo. Also discussed are potential limitations of the technique, complementary methods for assessing oxidative metabolism, and whether the P(i) → ATP flux is a viable biomarker of metabolic function in vivo.
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Affiliation(s)
- Douglas E Befroy
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA.
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Abstract
Magnetic resonance spectroscopy (MRS) methods offer a potentially valuable window into cellular metabolism. Measurement of flux between inorganic phosphate (Pi) and ATP using (31)P MRS magnetization transfer has been used in resting muscle to assess what is claimed to be mitochondrial ATP synthesis and has been particularly popular in the study of insulin effects and insulin resistance. However, the measured Pi→ATP flux in resting skeletal muscle is far higher than the true rate of oxidative ATP synthesis, being dominated by a glycolytically mediated Pi↔ATP exchange reaction that is unrelated to mitochondrial function. Furthermore, even if measured accurately, the ATP production rate in resting muscle has no simple relationship to mitochondrial capacity as measured either ex vivo or in vivo. We summarize the published measurements of Pi→ATP flux, concentrating on work relevant to diabetes and insulin, relate it to current understanding of the physiology of mitochondrial ATP synthesis and glycolytic Pi↔ATP exchange, and discuss some possible implications of recently reported correlations between Pi→ATP flux and other physiological measures.
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Affiliation(s)
- Graham J Kemp
- Department of Musculoskeletal Biology and Magnetic Resonance and Image Analysis Research Centre, University of Liverpool, Liverpool, UK.
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Gahete MD, Córdoba-Chacón J, Anadumaka CV, Lin Q, Brüning JC, Kahn CR, Luque RM, Kineman RD. Elevated GH/IGF-I, due to somatotrope-specific loss of both IGF-I and insulin receptors, alters glucose homeostasis and insulin sensitivity in a diet-dependent manner. Endocrinology 2011; 152:4825-37. [PMID: 21990313 PMCID: PMC3230054 DOI: 10.1210/en.2011-1447] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A unique mouse model was developed with elevated endogenous GH (2- to 3-fold) and IGF-I (1.2- to 1.4-fold), due to somatotrope-specific Cre-mediated inactivation of IGF-I receptor (IgfIr) and insulin receptor (Insr) genes (IgfIr,Insr(rGHpCre), referred to as HiGH mice). We demonstrate that the metabolic phenotype of HiGH mice is diet dependent and differs from that observed in other mouse models of GH excess due to ectopic heterologous transgene expression or pituitary tumor formation. Elevated endogenous GH promotes lean mass and whole-body lipid oxidation but has minimal effects on adiposity, even in response to diet-induced obesity. When caloric intake is moderated, elevated GH improves glucose clearance, despite low/normal insulin sensitivity, which may be explained in part by enhanced IGF-I and insulin output. However, when caloric intake is in excess, elevated GH promotes hepatic lipid accumulation, insulin resistance, hyperglycemia, and ketosis. The HiGH mouse model represents a useful tool to study the role endogenous circulating GH levels play in regulating health and disease.
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Affiliation(s)
- Manuel D Gahete
- Jesse Brown Veterans Affairs Medical Center, Research and Development Division, 820 South Damen Avenue, Chicago, Illinois 60612, USA
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Szendroedi J, Phielix E, Roden M. The role of mitochondria in insulin resistance and type 2 diabetes mellitus. Nat Rev Endocrinol 2011; 8:92-103. [PMID: 21912398 DOI: 10.1038/nrendo.2011.138] [Citation(s) in RCA: 415] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Type 2 diabetes mellitus (T2DM) has been related to alterations of oxidative metabolism in insulin-responsive tissues. Overt T2DM can present with acquired or inherited reductions of mitochondrial oxidative phosphorylation capacity, submaximal ADP-stimulated oxidative phosphorylation and plasticity of mitochondria and/or lower mitochondrial content in skeletal muscle cells and potentially also in hepatocytes. Acquired insulin resistance is associated with reduced insulin-stimulated mitochondrial activity as the result of blunted mitochondrial plasticity. Hereditary insulin resistance is frequently associated with reduced mitochondrial activity at rest, probably due to diminished mitochondrial content. Lifestyle and pharmacological interventions can enhance the capacity for oxidative phosphorylation and mitochondrial content and improve insulin resistance in some (pre)diabetic cases. Various mitochondrial features can be abnormal but are not necessarily responsible for all forms of insulin resistance. Nevertheless, mitochondrial abnormalities might accelerate progression of insulin resistance and subsequent organ dysfunction via increased production of reactive oxygen species. This Review discusses the association between mitochondrial function and insulin sensitivity in various tissues, such as skeletal muscle, liver and heart, with a main focus on studies in humans, and addresses the effects of therapeutic strategies that affect mitochondrial function and insulin sensitivity.
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Affiliation(s)
- Julia Szendroedi
- Institute for Clinical Diabetology, German Diabetes Center, D-40225 Düsseldorf, Germany
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Vijayakumar A, Yakar S, LeRoith D. The intricate role of growth hormone in metabolism. Front Endocrinol (Lausanne) 2011; 2:32. [PMID: 22654802 PMCID: PMC3356038 DOI: 10.3389/fendo.2011.00032] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 08/30/2011] [Indexed: 11/18/2022] Open
Abstract
Growth hormone (GH), a master regulator of somatic growth, also regulates carbohydrate and lipid metabolism via complex interactions with insulin and insulin-like growth factor-1 (IGF-1). Data from human and rodent studies reveal the importance of GH in insulin synthesis and secretion, lipid metabolism and body fat remodeling. In this review, we will summarize the tissue-specific metabolic effects of GH, with emphasis on recent targets identified to mediate these effects. Furthermore, we will discuss what role GH plays in obesity and present possible mechanisms by which this may occur.
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Affiliation(s)
- Archana Vijayakumar
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine, Mount Sinai School of MedicineNew York, NY, USA
| | - Shoshana Yakar
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine, Mount Sinai School of MedicineNew York, NY, USA
| | - Derek LeRoith
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine, Mount Sinai School of MedicineNew York, NY, USA
- *Correspondence: Derek LeRoith, Division of Endocrinology, Diabetes and Bone Disease, Mount Sinai School of Medicine, One Gustav Levy Place, Box 1055, New York, NY 10029-6574, USA. e-mail:
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Vijayakumar A, Novosyadlyy R, Wu Y, Yakar S, LeRoith D. Biological effects of growth hormone on carbohydrate and lipid metabolism. Growth Horm IGF Res 2010; 20:1-7. [PMID: 19800274 PMCID: PMC2815161 DOI: 10.1016/j.ghir.2009.09.002] [Citation(s) in RCA: 186] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 09/01/2009] [Accepted: 09/04/2009] [Indexed: 01/05/2023]
Abstract
This review will summarize the metabolic effects of growth hormone (GH) on the adipose tissue, liver, and skeletal muscle with focus on lipid and carbohydrate metabolism. The metabolic effects of GH predominantly involve the stimulation of lipolysis in the adipose tissue resulting in an increased flux of free fatty acids (FFAs) into the circulation. In the muscle and liver, GH stimulates triglyceride (TG) uptake, by enhancing lipoprotein lipase (LPL) expression, and its subsequent storage. The effects of GH on carbohydrate metabolism are more complicated and may be mediated indirectly via the antagonism of insulin action. Furthermore, GH has a net anabolic effect on protein metabolism although the molecular mechanisms of its actions are not completely understood. The major questions that still remain to be answered are (i) What are the molecular mechanisms by which GH regulates substrate metabolism? (ii) Does GH affect substrate metabolism directly or indirectly via IGF-1 or antagonism of insulin action?
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Affiliation(s)
- Archana Vijayakumar
- Division of Endocrinology, Diabetes and Bone Diseases, The Samuel Bronfman Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA
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Structure-function relationships in feedback regulation of energy fluxes in vivo in health and disease: mitochondrial interactosome. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:678-97. [PMID: 20096261 DOI: 10.1016/j.bbabio.2010.01.011] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2009] [Revised: 01/08/2010] [Accepted: 01/12/2010] [Indexed: 12/13/2022]
Abstract
The aim of this review is to analyze the results of experimental research of mechanisms of regulation of mitochondrial respiration in cardiac and skeletal muscle cells in vivo obtained by using the permeabilized cell technique. Such an analysis in the framework of Molecular Systems Bioenergetics shows that the mechanisms of regulation of energy fluxes depend on the structural organization of the cells and interaction of mitochondria with cytoskeletal elements. Two types of cells of cardiac phenotype with very different structures were analyzed: adult cardiomyocytes and continuously dividing cancerous HL-1 cells. In cardiomyocytes mitochondria are arranged very regularly, and show rapid configuration changes of inner membrane but no fusion or fission, diffusion of ADP and ATP is restricted mostly at the level of mitochondrial outer membrane due to an interaction of heterodimeric tubulin with voltage dependent anion channel, VDAC. VDAC with associated tubulin forms a supercomplex, Mitochondrial Interactosome, with mitochondrial creatine kinase, MtCK, which is structurally and functionally coupled to ATP synthasome. Due to selectively limited permeability of VDAC for adenine nucleotides, mitochondrial respiration rate depends almost linearly upon the changes of cytoplasmic ADP concentration in their physiological range. Functional coupling of MtCK with ATP synthasome amplifies this signal by recycling adenine nucleotides in mitochondria coupled to effective phosphocreatine synthesis. In cancerous HL-1 cells this complex is significantly modified: tubulin is replaced by hexokinase and MtCK is lacking, resulting in direct utilization of mitochondrial ATP for glycolytic lactate production and in this way contributing in the mechanism of the Warburg effect. Systemic analysis of changes in the integrated system of energy metabolism is also helpful for better understanding of pathogenesis of many other diseases.
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