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Deja S, Fletcher JA, Kim CW, Kucejova B, Fu X, Mizerska M, Villegas M, Pudelko-Malik N, Browder N, Inigo-Vollmer M, Menezes CJ, Mishra P, Berglund ED, Browning JD, Thyfault JP, Young JD, Horton JD, Burgess SC. Hepatic malonyl-CoA synthesis restrains gluconeogenesis by suppressing fat oxidation, pyruvate carboxylation, and amino acid availability. Cell Metab 2024:S1550-4131(24)00050-0. [PMID: 38447582 DOI: 10.1016/j.cmet.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 12/10/2023] [Accepted: 02/09/2024] [Indexed: 03/08/2024]
Abstract
Acetyl-CoA carboxylase (ACC) promotes prandial liver metabolism by producing malonyl-CoA, a substrate for de novo lipogenesis and an inhibitor of CPT-1-mediated fat oxidation. We report that inhibition of ACC also produces unexpected secondary effects on metabolism. Liver-specific double ACC1/2 knockout (LDKO) or pharmacologic inhibition of ACC increased anaplerosis, tricarboxylic acid (TCA) cycle intermediates, and gluconeogenesis by activating hepatic CPT-1 and pyruvate carboxylase flux in the fed state. Fasting should have marginalized the role of ACC, but LDKO mice maintained elevated TCA cycle intermediates and preserved glycemia during fasting. These effects were accompanied by a compensatory induction of proteolysis and increased amino acid supply for gluconeogenesis, which was offset by increased protein synthesis during feeding. Such adaptations may be related to Nrf2 activity, which was induced by ACC inhibition and correlated with fasting amino acids. The findings reveal unexpected roles for malonyl-CoA synthesis in liver and provide insight into the broader effects of pharmacologic ACC inhibition.
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Affiliation(s)
- Stanislaw Deja
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Justin A Fletcher
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Clinical Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Chai-Wan Kim
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Blanka Kucejova
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Xiaorong Fu
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Monika Mizerska
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Morgan Villegas
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Natalia Pudelko-Malik
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Nicholas Browder
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Melissa Inigo-Vollmer
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Cameron J Menezes
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Prashant Mishra
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Eric D Berglund
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Jeffrey D Browning
- Department of Clinical Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - John P Thyfault
- Departments of Cell Biology and Physiology, Internal Medicine and KU Diabetes Institute, Kansas Medical Center, Kansas City, KS, USA
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37235, USA
| | - Jay D Horton
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA.
| | - Shawn C Burgess
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA.
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Fu X, Fletcher JA, Deja S, Inigo-Vollmer M, Burgess SC, Browning JD. Persistent fasting lipogenesis links impaired ketogenesis with citrate synthesis in humans with non-alcoholic fatty liver. J Clin Invest 2023; 133:167442. [PMID: 36928190 PMCID: PMC10145942 DOI: 10.1172/jci167442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 03/14/2023] [Indexed: 03/17/2023] Open
Abstract
BACKGROUND Hepatic de novo lipogenesis (DNL) and β-oxidation are tightly coordinated, and their dysregulation is thought to contribute to the pathogenesis of non-alcoholic fatty liver (NAFL). Fasting normally relaxes DNL-mediated inhibition of hepatic β-oxidation, dramatically increasing ketogenesis and decreasing reliance on the TCA cycle. Thus, we tested whether aberrant oxidative metabolism in fasting NAFL subjects is related to the inability to halt fasting DNL. METHODS Forty consecutive non-diabetic individuals with and without a history of NAFL were recruited for this observational study. After phenotyping, subjects fasted for 24-hr, and hepatic metabolism was interrogated using a combination of 2H2O and 13C tracers, magnetic resonance spectroscopy, and high-resolution mass spectrometry. RESULTS Within a subset of subjects, DNL was detectable after a 24-hr fast and was more prominent in those with NAFL, though it was poorly correlated with steatosis. However, fasting DNL negatively correlated with hepatic β-oxidation and ketogenesis and positively correlated with citrate synthesis. Subjects with NAFL but undetectable fasting DNL (25th percentile) were comparatively normal. However, those with the highest fasting DNL (75th percentile) were intransigent to the effects of fasting on the concentration of insulin, NEFA, and ketones. Additionally, they sustained glycogenolysis and spared the loss of oxaloacetate to gluconeogenesis in favor of citrate synthesis, which correlated with DNL and diminished ketogenesis. CONCLUSION Metabolic flux analysis in fasted subjects indicates that shared metabolic mechanisms link the dysregulations of hepatic DNL, ketogenesis, and the TCA cycle in NAFL. TRIAL REGISTRATION Data obtained during the enrollment/non-intervention phase of Effect of Vitamin E on Non-Alcoholic Fatty Liver Disease; ClinicalTrials.gov NCT02690792.
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Affiliation(s)
- Xiaorong Fu
- Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas, Dallas, United States of America
| | - Justin A Fletcher
- Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas, Dallas, United States of America
| | - Stanisław Deja
- Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas, Dallas, United States of America
| | - Melissa Inigo-Vollmer
- Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas, Dallas, United States of America
| | - Shawn C Burgess
- Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas, Dallas, United States of America
| | - Jeffrey D Browning
- Departments of Clinical Nutrition, University of Texas Southwestern Medical Center at Dallas, Dallas, United States of America
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Martino MR, Gutiérrez-Aguilar M, Yiew NKH, Lutkewitte AJ, Singer JM, McCommis KS, Ferguson D, Liss KHH, Yoshino J, Renkemeyer MK, Smith GI, Cho K, Fletcher JA, Klein S, Patti GJ, Burgess SC, Finck BN. Silencing alanine transaminase 2 in diabetic liver attenuates hyperglycemia by reducing gluconeogenesis from amino acids. Cell Rep 2022; 39:110733. [PMID: 35476997 PMCID: PMC9121396 DOI: 10.1016/j.celrep.2022.110733] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 02/21/2022] [Accepted: 04/02/2022] [Indexed: 12/13/2022] Open
Abstract
Hepatic gluconeogenesis from amino acids contributes significantly to diabetic hyperglycemia, but the molecular mechanisms involved are incompletely understood. Alanine transaminases (ALT1 and ALT2) catalyze the interconversion of alanine and pyruvate, which is required for gluconeogenesis from alanine. We find that ALT2 is overexpressed in the liver of diet-induced obese and db/db mice and that the expression of the gene encoding ALT2 (GPT2) is downregulated following bariatric surgery in people with obesity. The increased hepatic expression of Gpt2 in db/db liver is mediated by activating transcription factor 4, an endoplasmic reticulum stress-activated transcription factor. Hepatocyte-specific knockout of Gpt2 attenuates incorporation of 13C-alanine into newly synthesized glucose by hepatocytes. In vivo Gpt2 knockdown or knockout in liver has no effect on glucose concentrations in lean mice, but Gpt2 suppression alleviates hyperglycemia in db/db mice. These data suggest that ALT2 plays a significant role in hepatic gluconeogenesis from amino acids in diabetes. Martino et al. find that alanine transaminase 2 (ALT2), which is encoded by Gpt2, is increased in liver of mice and people with obesity by activating transcription factor 4. Suppression of Gpt2 expression in obese, but not lean mice, lowers blood glucose by suppressing alanine-mediated gluconeogenesis.
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Affiliation(s)
- Michael R Martino
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Manuel Gutiérrez-Aguilar
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Nicole K H Yiew
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Andrew J Lutkewitte
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Jason M Singer
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Kyle S McCommis
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Daniel Ferguson
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Kim H H Liss
- Department of Pediatrics, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Jun Yoshino
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - M Katie Renkemeyer
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Gordon I Smith
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Kevin Cho
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Justin A Fletcher
- Center for Human Nutrition, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Samuel Klein
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Gary J Patti
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA; Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA; Siteman Cancer Center, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Shawn C Burgess
- Center for Human Nutrition, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Brian N Finck
- Department of Medicine, Center for Human Nutrition, Washington University in St. Louis, St. Louis, MO 63110, USA.
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Luo F, Smagris E, Martin SA, Vale G, McDonald JG, Fletcher JA, Burgess SC, Hobbs HH, Cohen JC. Hepatic TM6SF2 Is Required for Lipidation of VLDL in a Pre-Golgi Compartment in Mice and Rats. Cell Mol Gastroenterol Hepatol 2021; 13:879-899. [PMID: 34923175 PMCID: PMC8804273 DOI: 10.1016/j.jcmgh.2021.12.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Substitution of lysine for glutamic acid at residu 167 in Transmembrane 6 superfamily member 2 (TM6SF2) is associated with fatty liver disease and reduced plasma lipid levels. Tm6sf2-/- mice replicate the human phenotype but were not suitable for detailed mechanistic studies. As an alternative model, we generated Tm6sf2-/- rats to determine the subcellular location and function of TM6SF2. METHODS Two lines of Tm6sf2-/- rats were established using gene editing. Lipids from tissues and from newly secreted very low density lipoproteins (VLDLs) were quantified using enzymatic assays and mass spectrometry. Neutral lipids were visualized in tissue sections using Oil Red O staining. The rate of dietary triglyceride (TG) absorption and hepatic VLDL-TG secretion were compared in Tm6sf2-/- mice and in their wild-type littermates. The intracellular location of TM6SF2 was determined by cell fractionation. Finally, TM6SF2 was immunoprecipitated from liver and enterocytes to identify interacting proteins. RESULTS Tm6sf2-/- rats had a 6-fold higher mean hepatic TG content (56.1 ± 28.9 9 vs 9.8 ± 3.9 mg/g; P < .0001) and lower plasma cholesterol levels (99.0 ± 10.5 vs 110.6 ± 14.0 mg/dL; P = .0294) than their wild-type littermates. Rates of appearance of dietary and hepatic TG into blood were reduced significantly in Tm6sf2-/- rats (P < .001 and P < .01, respectively). Lipid content of newly secreted VLDLs isolated from perfused livers was reduced by 53% (TG) and 62% (cholesterol) (P = .005 and P = .01, respectively) in Tm6sf2-/- mice. TM6SF2 was present predominantly in the smooth endoplasmic reticulum and endoplasmic reticulum-Golgi intermediate compartments, but not in Golgi. Both apolipoprotein B-48 and acyl-CoA synthetase long chain family member 5 physically interacted with TM6SF2. CONCLUSIONS TM6SF2 acts in the smooth endoplasmic reticulum to promote bulk lipidation of apolipoprotein B-containing lipoproteins, thus preventing fatty liver disease.
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Affiliation(s)
- Fei Luo
- Department of Molecular Genetics, Dallas, Texas,Department of Cardiovascular Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | | | | | - Goncalo Vale
- Department of Molecular Genetics, Dallas, Texas,Center for Human Nutrition, Dallas, Texas
| | - Jeffrey G. McDonald
- Department of Molecular Genetics, Dallas, Texas,Center for Human Nutrition, Dallas, Texas
| | | | | | - Helen H. Hobbs
- Department of Molecular Genetics, Dallas, Texas,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas,Correspondence Address correspondence to: Helen H. Hobbs, MD, or Jonathan C. Cohen, PhD, Department of Molecular Genetics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 07390-9046.fax: (214) 648-7539.
| | - Jonathan C. Cohen
- Center for Human Nutrition, Dallas, Texas,Correspondence Address correspondence to: Helen H. Hobbs, MD, or Jonathan C. Cohen, PhD, Department of Molecular Genetics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 07390-9046.fax: (214) 648-7539.
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Luo F, Smagris E, Fletcher JA, Cohen JC, Hobbs HH. Hypolipidemia associated with inactivation of TM6SF2 is due to decreased VLDL-lipids secretion. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
A missense variant in Transmembrane 6 Superfamily Member 2 [TM6SF2 (E167K)] is associated with reduced plasma lipid levels and protection from coronary atherosclerosis. The substitution of lysine for glutamate at residue 167 is associated with a marked decrease in TM6SF2 protein expression, consistent with a loss-of-function mutation. However the biological role of TM6SF2 is not known, and the mechanism(s) responsible for the hypolipidemia associated with mutation gene has not been fully defined. To elucidate the pathological mechanism for the hypolipidemia associated with TM6SF2 deficiency, we inactivated Tm6sf2 in mice and rats.
Methods
Tm6sf2−/− mice were generated as described previously. Two lines of Tm6sf2−/− rats with different frameshift mutations in exon 1 were generated using CRISPR/Cas9 technology. Primary hepatocytes were isolated from WT and Tm6sf2−/− mice for microscopy. Rats were fasted 16 or 4 hours and tissues were collected on ice for cell fractionation, and in liquid nitrogen for biochemical analyses. Frozen samples were stored at −80°C for subsequent analyses.
Result
In both mice and rats, inactivation of Tm6sf2 recapitulated the phenotype of humans with the E167K substitution: steatosis, reduced plasma lipid levels, and transaminitis. The phenotype was readily apparent in animals fed chow diets. Both species had reduced secretion of VLDL-TG, as determined by TRITON WR1399 injection, with no decrease in secretion of ApoB. Experiments in isolated perfused livers from WT and Tm6sf2−/− mice confirmed that the decreased TG secretion observed in intact animals reflected reduced TG secretion from the liver. Lipidomic analysis of the liver perfusates by by LC-MS indicated that secretion of cholesteryl esters, and phospholipids was also decreased in the KO animals. Taken together, these findings are consistent with a role for TM6SF2 in lipidation of ApoB-containing lipoproteins. To further elucidate the function of TM6SF2, we used fluorescence microscopy and cell fractionation to determine the subcellular localization of the protein. Microscopic analysis showed that TM6SF2 co-localized with ER and Golgi markers, but cell fractionation studies indicated that the protein is located primarily in the smooth ER. The ratio of TG to ApoB was lower in Golgi fractions from TM6sf2−/− rats than in corresponding fractions from WT animals.
Conclusions
Since the sequela of TM6SF2 inactivation are already apparent in the Golgi, we speculate that TM6SF2 promotes lipidation of VLDL in a pre-Golgi compartment. We are currently performing additional studies to further define the specific mechanism whereby TM6SF2 promotes lipidation of ApoB-containing lipoproteins.
Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): National Institutes of Health
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Affiliation(s)
- F Luo
- The Second Xiangya Hospital of Central South University, Department of Cardiovascular Medicine, Changsha, China
| | - E Smagris
- University of Texas Southwestern Medical Center, Department of Molecular Genetics, Dallas, United States of America
| | - J A Fletcher
- University of Texas Southwestern Medical Center, Center for Human Nutrition, Dallas, United States of America
| | - J C Cohen
- University of Texas Southwestern Medical Center, Internal Medicine, Dallas, United States of America
| | - H H Hobbs
- University of Texas Southwestern Medical Center, Department of Molecular Genetics, Dallas, United States of America
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Demetri GD, Antonescu CR, Bjerkehagen B, Bovée JVMG, Boye K, Chacón M, Dei Tos AP, Desai J, Fletcher JA, Gelderblom H, George S, Gronchi A, Haas RL, Hindi N, Hohenberger P, Joensuu H, Jones RL, Judson I, Kang YK, Kawai A, Lazar AJ, Le Cesne A, Maestro R, Maki RG, Martín J, Patel S, Penault-Llorca F, Premanand Raut C, Rutkowski P, Safwat A, Sbaraglia M, Schaefer IM, Shen L, Serrano C, Schöffski P, Stacchiotti S, Sundby Hall K, Tap WD, Thomas DM, Trent J, Valverde C, van der Graaf WTA, von Mehren M, Wagner A, Wardelmann E, Naito Y, Zalcberg J, Blay JY. Diagnosis and management of tropomyosin receptor kinase (TRK) fusion sarcomas: expert recommendations from the World Sarcoma Network. Ann Oncol 2020; 31:1506-1517. [PMID: 32891793 PMCID: PMC7985805 DOI: 10.1016/j.annonc.2020.08.2232] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 12/22/2022] Open
Abstract
Sarcomas are a heterogeneous group of malignancies with mesenchymal lineage differentiation. The discovery of neurotrophic tyrosine receptor kinase (NTRK) gene fusions as tissue-agnostic oncogenic drivers has led to new personalized therapies for a subset of patients with sarcoma in the form of tropomyosin receptor kinase (TRK) inhibitors. NTRK gene rearrangements and fusion transcripts can be detected with different molecular pathology techniques, while TRK protein expression can be demonstrated with immunohistochemistry. The rarity and diagnostic complexity of NTRK gene fusions raise a number of questions and challenges for clinicians. To address these challenges, the World Sarcoma Network convened two meetings of expert adult oncologists and pathologists and subsequently developed this article to provide practical guidance on the management of patients with sarcoma harboring NTRK gene fusions. We propose a diagnostic strategy that considers disease stage and histologic and molecular subtypes to facilitate routine testing for TRK expression and subsequent testing for NTRK gene fusions.
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Affiliation(s)
- G D Demetri
- Dana-Farber Cancer Institute and Ludwig Center at Harvard Medical School, Boston, USA
| | - C R Antonescu
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, USA
| | - B Bjerkehagen
- Department of Pathology, Oslo University Hospital, Oslo, Norway
| | - J V M G Bovée
- Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands
| | - K Boye
- Department of Oncology, Oslo University Hospital, Oslo, Norway
| | - M Chacón
- Oncology Service Chair, Instituto Alexander Fleming, Buenos Aires, Argentina
| | - A P Dei Tos
- Department of Pathology, University of Padua, Padova, Italy
| | - J Desai
- Peter MacCallum Cancer Centre, University of Melbourne, Melbourne, Australia
| | - J A Fletcher
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
| | - H Gelderblom
- Department of Medical Oncology, Leiden University Medical Centre, Leiden, The Netherlands
| | - S George
- Medical Oncology, Dana-Farber Cancer Institute, Boston, USA
| | - A Gronchi
- Department of Surgery, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy
| | - R L Haas
- Department of Radiotherapy, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - N Hindi
- Institute of Biomedicine of Sevilla (IBIS, HUVR, CSIC, Universidad de Sevilla), Sevilla, Spain; Medical Oncology Department, University Hospital Virgen del Rocio, Sevilla, Spain
| | - P Hohenberger
- Division of Surgical Oncology and Thoracic Surgery, Mannheim University Medical Center, Mannheim, Germany
| | - H Joensuu
- Department of Oncology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - R L Jones
- Sarcoma Unit, Royal Marsden NHS Foundation Trust, London, UK; Division of Clinical Studies, Institute of Cancer Research, London, UK
| | - I Judson
- Division of Clinical Studies, Institute of Cancer Research, London, UK
| | - Y-K Kang
- Department of Oncology, University of Ulsan College of Medicine, Seoul, Korea
| | - A Kawai
- Department of Musculoskeletal Oncology, National Cancer Center, Tokyo, Japan
| | - A J Lazar
- Pathology, The University of Texas MD Anderson Cancer Center, Houston, USA
| | - A Le Cesne
- Medical Oncology, Insitut Gustave Roussy, Villejuif, Ile-de-France, France
| | - R Maestro
- Unit of Oncogenetics and Functional Oncogenomics, Centro di Riferimento Oncologico di Aviano (CRO Aviano) IRCCS, National Cancer Institute, Aviano, Italy
| | - R G Maki
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - J Martín
- Institute of Biomedicine of Sevilla (IBIS, HUVR, CSIC, Universidad de Sevilla), Sevilla, Spain; Medical Oncology Department, University Hospital Virgen del Rocio, Sevilla, Spain
| | - S Patel
- Department of Sarcoma Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, USA
| | | | - C Premanand Raut
- Division of Surgical Oncology, Brigham and Women's Hospital, Center for Sarcoma and Bone Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, USA
| | - P Rutkowski
- Department of Soft Tissue/Bone Sarcoma and Melanoma, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - A Safwat
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - M Sbaraglia
- Department of Pathology, University of Padua, Padova, Italy
| | - I-M Schaefer
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
| | - L Shen
- Department of GI Oncology, Peking University Cancer Hospital and Institute, Beijing, China
| | - C Serrano
- Sarcoma Translational Research Program, Vall d'Hebron Institute of Oncology, Barcelona, Spain; Medical Oncology Department, Vall d'Hebron Hospital, Barcelona, Spain
| | - P Schöffski
- Department of General Medical Oncology, Leuven Cancer Institute, University Hospitals Leuven, Leuven, Belgium
| | - S Stacchiotti
- Cancer Medicine Department, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy
| | - K Sundby Hall
- Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - W D Tap
- Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, USA
| | - D M Thomas
- The Kinghorn Cancer Centre and Cancer Theme, Garvan Institute of Medical Research, Darlinghurst, Australia
| | - J Trent
- Sylvester Comprehensive Cancer Center at University of Miami Miller School of Medicine, Miami, USA
| | - C Valverde
- Medical Oncology Department, Vall d'Hebron Hospital, Barcelona, Spain
| | - W T A van der Graaf
- Department of Medical Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands; Department of Medical Oncology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - M von Mehren
- Department of Hematology and Medical Oncology, Fox Chase Cancer Center, Philadelphia, USA
| | - A Wagner
- Dana-Farber Cancer Institute and Harvard Medical School, Boston, USA
| | - E Wardelmann
- Gerhard Domagk Institute of Pathology, University of Münster, Münster, Germany
| | - Y Naito
- National Cancer Center Hospital East, Kashiwa, Japan
| | - J Zalcberg
- Department of Epidemiology and Preventative Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia; Department of Medical Oncology, Alfred Health, Melbourne, Australia
| | - J-Y Blay
- Centre Léon Bérard, Unicancer, LYRICAN and Université Claude Bernard Lyon 1, Lyon, France.
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7
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Deja S, Fu X, Fletcher JA, Kucejova B, Browning JD, Young JD, Burgess SC. Simultaneous tracers and a unified model of positional and mass isotopomers for quantification of metabolic flux in liver. Metab Eng 2019; 59:1-14. [PMID: 31891762 DOI: 10.1016/j.ymben.2019.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 12/12/2019] [Accepted: 12/21/2019] [Indexed: 12/23/2022]
Abstract
Computational models based on the metabolism of stable isotope tracers can yield valuable insight into the metabolic basis of disease. The complexity of these models is limited by the number of tracers and the ability to characterize tracer labeling in downstream metabolites. NMR spectroscopy is ideal for multiple tracer experiments since it precisely detects the position of tracer nuclei in molecules, but it lacks sensitivity for detecting low-concentration metabolites. GC-MS detects stable isotope mass enrichment in low-concentration metabolites, but lacks nuclei and positional specificity. We performed liver perfusions and in vivo infusions of 2H and 13C tracers, yielding complex glucose isotopomers that were assigned by NMR and fit to a newly developed metabolic model. Fluxes regressed from 2H and 13C NMR positional isotopomer enrichments served to validate GC-MS-based flux estimates obtained from the same experimental samples. NMR-derived fluxes were largely recapitulated by modeling the mass isotopomer distributions of six glucose fragment ions measured by GC-MS. Modest differences related to limited fragmentation coverage of glucose C1-C3 were identified, but fluxes such as gluconeogenesis, glycogenolysis, cataplerosis and TCA cycle flux were tightly correlated between the methods. Most importantly, modeling of GC-MS data could assign fluxes in primary mouse hepatocytes, an experiment that is impractical by 2H or 13C NMR.
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Affiliation(s)
- Stanislaw Deja
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Xiaorong Fu
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Justin A Fletcher
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Blanka Kucejova
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jeffrey D Browning
- Department of Clinical Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37235, USA.
| | - Shawn C Burgess
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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Cappel DA, Deja S, Duarte JAG, Kucejova B, Iñigo M, Fletcher JA, Fu X, Berglund ED, Liu T, Elmquist JK, Hammer S, Mishra P, Browning JD, Burgess SC. Pyruvate-Carboxylase-Mediated Anaplerosis Promotes Antioxidant Capacity by Sustaining TCA Cycle and Redox Metabolism in Liver. Cell Metab 2019; 29:1291-1305.e8. [PMID: 31006591 PMCID: PMC6585968 DOI: 10.1016/j.cmet.2019.03.014] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 01/12/2019] [Accepted: 03/26/2019] [Indexed: 01/09/2023]
Abstract
The hepatic TCA cycle supports oxidative and biosynthetic metabolism. This dual responsibility requires anaplerotic pathways, such as pyruvate carboxylase (PC), to generate TCA cycle intermediates necessary for biosynthesis without disrupting oxidative metabolism. Liver-specific PC knockout (LPCKO) mice were created to test the role of anaplerotic flux in liver metabolism. LPCKO mice have impaired hepatic anaplerosis, diminution of TCA cycle intermediates, suppressed gluconeogenesis, reduced TCA cycle flux, and a compensatory increase in ketogenesis and renal gluconeogenesis. Loss of PC depleted aspartate and compromised urea cycle function, causing elevated urea cycle intermediates and hyperammonemia. Loss of PC prevented diet-induced hyperglycemia and insulin resistance but depleted NADPH and glutathione, which exacerbated oxidative stress and correlated with elevated liver inflammation. Thus, despite catalyzing the synthesis of intermediates also produced by other anaplerotic pathways, PC is specifically necessary for maintaining oxidation, biosynthesis, and pathways distal to the TCA cycle, such as antioxidant defenses.
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Affiliation(s)
- David A Cappel
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Stanisław Deja
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - João A G Duarte
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Blanka Kucejova
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Melissa Iñigo
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Justin A Fletcher
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiaorong Fu
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Eric D Berglund
- Center for Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, USA; Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Tiemin Liu
- Sate Key Laboratory of Genetic Engineering, School of Life Sciences, Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, Shanghai 200438, China
| | - Joel K Elmquist
- Center for Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Suntrea Hammer
- Department of Pathology, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Prashant Mishra
- Children's Medical Center Research Institute, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey D Browning
- Department of Clinical Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Shawn C Burgess
- Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, TX, USA.
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9
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Fletcher JA, Deja S, Satapati S, Fu X, Burgess SC, Browning JD. Impaired ketogenesis and increased acetyl-CoA oxidation promote hyperglycemia in human fatty liver. JCI Insight 2019; 5:127737. [PMID: 31012869 DOI: 10.1172/jci.insight.127737] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent, and potentially morbid, disease that affects one-third of the U.S. population. Normal liver safely accommodates lipid excess during fasting or carbohydrate restriction by increasing their oxidation to acetyl-CoA and ketones, yet lipid excess during NAFLD leads to hyperglycemia and, in some, steatohepatitis. To examine potential mechanisms, flux through pathways of hepatic oxidative metabolism and gluconeogenesis were studied using five simultaneous stable isotope tracers in ketotic (24-hour fast) individuals with a wide range of hepatic triglyceride contents (0-52%). Ketogenesis was progressively impaired as hepatic steatosis and glycemia worsened. Conversely, the alternative pathway for acetyl-CoA metabolism, oxidation in the tricarboxylic (TCA) cycle, was upregulated in NAFLD as ketone production diminished and positively correlated with rates of gluconeogenesis and plasma glucose concentrations. Increased respiration and energy generation that occurred in liver when β-oxidation and TCA cycle activity were coupled may explain these findings, inasmuch as oxygen consumption was higher during fatty liver and highly correlated with gluconeogenesis. These findings demonstrate that increased glucose production and hyperglycemia in NAFLD is not a consequence of acetyl-CoA production per se, but how acetyl-CoA is further metabolized in liver.
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Affiliation(s)
| | | | | | | | | | - Jeffrey D Browning
- Advanced Imaging Research Center.,Department of Internal Medicine, and.,Department of Clinical Nutrition, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
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10
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Fletcher JA, Linden MA, Sheldon RD, Meers GM, Morris EM, Butterfield A, Perfield JW, Rector RS, Thyfault JP. Fibroblast growth factor 21 increases hepatic oxidative capacity but not physical activity or energy expenditure in hepatic peroxisome proliferator-activated receptor γ coactivator-1α-deficient mice. Exp Physiol 2018; 103:408-418. [PMID: 29215172 DOI: 10.1113/ep086629] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 11/28/2017] [Indexed: 02/06/2023]
Abstract
NEW FINDINGS What is the central question of this study? Does a reduction in hepatic peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), which has been observed in an insulin-resistant obese state, impair the ability of fibroblast growth factor 21 (FGF21) to modulate metabolism? What is the main finding and its importance? A deficit in hepatic PGC-1α does not compromise the ability of FGF21 to increase hepatic fatty acid oxidation; however, the effects of FGF21 to regulate whole-body metabolism (i.e. total and resting energy expenditure), as well as ambulatory activity, were altered when hepatic PGC-1α was reduced. ABSTRACT Fibroblast growth factor 21 (FGF21) treatment drives metabolic improvements, including increased metabolic flux and reduced hepatic steatosis, but the mechanisms responsible for these effects remain to be elucidated fully. We tested whether a targeted reduction in hepatic peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), which has been shown to occur with obesity, had a negative impact on the metabolic effects of FGF21. We infused FGF21 (1 mg kg-1 day-1 ) or saline in chow-fed wild-type (WT) and liver-specific PGC-1α heterozygous (LPGC-1α) mice for 4 weeks. Administration of FGF21 lowered serum insulin and cholesterol (P ≤ 0.05) and tended to lower free fatty acids (P = 0.057). The LPGC-1α mice exhibited reduced complete hepatic fatty acid oxidation (FAO; LPGC-1α, 1788 ± 165 nmol g-1 h-1 compared with WT, 2572 ± 437 nmol g-1 h-1 ; P < 0.001), which was normalized by FGF21 treatment (2788 ± 519 nmol g-1 h-1 ; P < 0.001). FGF21 also increased hepatic incomplete FAO by 12% in both groups and extramitochondrial FAO by 89 and 56% in WT and LPGC-1α mice, respectfully (P = 0.001), and lowered hepatic triacylglycerol by 30-40% (P < 0.001). Chronic treatment with FGF21 lowered body weight and fat mass (P < 0.05), while increasing food consumption (P < 0.05), total energy expenditure [7.3 ± 0.60 versus 6.6 ± 0.39 kcal (12 h)-1 in WT mice; P = 0.009] and resting energy expenditure [5.4 ± 0.89 versus 4.6 ± 0.21 kcal (12 h)-1 in WT mice; P = 0.005]. Interestingly, FGF21 only increased ambulatory activity in the WT mice (P = 0.03), without a concomitant increase in non-resting energy expenditure. In conclusion, although reduced hepatic PGC-1α expression was not necessary for FGF21 to increase FAO, it does appear to mediate FGF21-induced changes in total and resting energy expenditure and ambulatory activity in lean mice.
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Affiliation(s)
- Justin A Fletcher
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, USA.,Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, MO, USA.,University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Melissa A Linden
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, USA.,Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, MO, USA
| | - Ryan D Sheldon
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, USA.,Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, MO, USA
| | - Grace M Meers
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, MO, USA.,Medicine - Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO, USA
| | - E Matthew Morris
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | | | - James W Perfield
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - R Scott Rector
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, USA.,Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, MO, USA.,Medicine - Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO, USA
| | - John P Thyfault
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA.,Kansas City Veterans Affairs Medical Center, Research Service, Kansas City, MO, USA
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11
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Porter JW, Rowles JL, Fletcher JA, Zidon TM, Winn NC, McCabe LT, Park YM, Perfield JW, Thyfault JP, Rector RS, Padilla J, Vieira-Potter VJ. Anti-inflammatory effects of exercise training in adipose tissue do not require FGF21. J Endocrinol 2017; 235:97-109. [PMID: 28765264 PMCID: PMC5581275 DOI: 10.1530/joe-17-0190] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 08/01/2017] [Indexed: 12/20/2022]
Abstract
Exercise enhances insulin sensitivity; it also improves adipocyte metabolism and reduces adipose tissue inflammation through poorly defined mechanisms. Fibroblast growth factor 21 (FGF21) is a pleiotropic hormone-like protein whose insulin-sensitizing properties are predominantly mediated via receptor signaling in adipose tissue (AT). Recently, FGF21 has also been demonstrated to have anti-inflammatory properties. Meanwhile, an association between exercise and increased circulating FGF21 levels has been reported in some, but not all studies. Thus, the role that FGF21 plays in mediating the positive metabolic effects of exercise in AT are unclear. In this study, FGF21-knockout (KO) mice were used to directly assess the role of FGF21 in mediating the metabolic and anti-inflammatory effects of exercise on white AT (WAT) and brown AT (BAT). Male FGF21KO and wild-type mice were provided running wheels or remained sedentary for 8 weeks (n = 9-15/group) and compared for adiposity, insulin sensitivity (i.e., HOMA-IR, Adipo-IR) and AT inflammation and metabolic function (e.g., mitochondrial enzyme activity, subunit content). Adiposity and Adipo-IR were increased in FGF21KO mice and decreased by EX. The BAT of FGF21KO animals had reduced mitochondrial content and decreased relative mass, both normalized by EX. WAT and BAT inflammation was elevated in FGF21KO mice, reduced in both genotypes by EX. EX increased WAT Pgc1alpha gene expression, citrate synthase activity, COX I content and total AMPK content in WT but not FGF21KO mice. Collectively, these findings reveal a previously unappreciated anti-inflammatory role for FGF21 in WAT and BAT, but do not support that FGF21 is necessary for EX-mediated anti-inflammatory effects.
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Affiliation(s)
- Jay W Porter
- Department of Nutrition and Exercise PhysiologyUniversity of Missouri, Columbia, Missouri, USA
| | - Joe L Rowles
- Department of Nutrition and Exercise PhysiologyUniversity of Missouri, Columbia, Missouri, USA
- Division of Nutritional SciencesUniversity of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Justin A Fletcher
- Department of Nutrition and Exercise PhysiologyUniversity of Missouri, Columbia, Missouri, USA
- Research Service-Harry S Truman Memorial VA HospitalColumbia, Missouri, USA
- University of Texas Southwestern Medical CenterDallas, Texas, USA
| | - Terese M Zidon
- Department of Nutrition and Exercise PhysiologyUniversity of Missouri, Columbia, Missouri, USA
| | - Nathan C Winn
- Department of Nutrition and Exercise PhysiologyUniversity of Missouri, Columbia, Missouri, USA
| | - Leighton T McCabe
- Department of Nutrition and Exercise PhysiologyUniversity of Missouri, Columbia, Missouri, USA
| | - Young-Min Park
- Department of Nutrition and Exercise PhysiologyUniversity of Missouri, Columbia, Missouri, USA
- University of Colorado Denver - Anschutz Medical CampusDenver, Colorado, USA
| | | | - John P Thyfault
- Department of Molecular and Integrative PhysiologyUniversity of Kansas Medical Center, Kansas City, Kansas, USA
- Kansas City VA Medical CenterKansas City, Missouri, USA
| | - R Scott Rector
- Department of Nutrition and Exercise PhysiologyUniversity of Missouri, Columbia, Missouri, USA
- Research Service-Harry S Truman Memorial VA HospitalColumbia, Missouri, USA
| | - Jaume Padilla
- Department of Nutrition and Exercise PhysiologyUniversity of Missouri, Columbia, Missouri, USA
- Department of Child HealthUniversity of Missouri, Columbia, Missouri, USA
- Dalton Cardiovascular Research CenterUniversity of Missouri, Columbia, Missouri, USA
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12
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Morris EM, McCoin CS, Allen JA, Gastecki ML, Koch LG, Britton SL, Fletcher JA, Fu X, Ding WX, Burgess SC, Rector RS, Thyfault JP. Aerobic capacity mediates susceptibility for the transition from steatosis to steatohepatitis. J Physiol 2017; 595:4909-4926. [PMID: 28504310 DOI: 10.1113/jp274281] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 05/04/2017] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS Low intrinsic aerobic capacity is associated with increased all-cause and liver-related mortality in humans. Low intrinsic aerobic capacity in the low capacity runner (LCR) rat increases susceptibility to acute and chronic high-fat/high-sucrose diet-induced steatosis, without observed increases in liver inflammation. Addition of excess cholesterol to a high-fat/high-sucrose diet produced greater steatosis in LCR and high capacity runner (HCR) rats. However, the LCR rat demonstrated greater susceptibility to increased liver inflammatory and apoptotic markers compared to the HCR rat. The progressive non-alcoholic fatty liver disease observed in the LCR rats following western diet feeding was associated with further declines in liver fatty acid oxidation and mitochondrial respiratory capacity compared to HCR rats. ABSTRACT Low aerobic capacity increases risk for non-alcoholic fatty liver disease and liver-related disease mortality, but mechanisms mediating these effects remain unknown. We recently reported that rats bred for low aerobic capacity (low capacity runner; LCR) displayed susceptibility to high fat diet-induced steatosis in association with reduced hepatic mitochondrial fatty acid oxidation (FAO) and respiratory capacity compared to high aerobic capacity (high capacity runner; HCR) rats. Here we tested the impact of aerobic capacity on susceptibility for progressive liver disease following a 16-week 'western diet' (WD) high in fat (45% kcal), cholesterol (1% w/w) and sucrose (15% kcal). Unlike previously with a diet high in fat and sucrose alone, the inclusion of cholesterol in the WD induced hepatomegaly and steatosis in both HCR and LCR rats, while producing greater cholesterol ester accumulation in LCR compared to HCR rats. Importantly, WD-fed low-fitness LCR rats displayed greater inflammatory cell infiltration, serum alanine transaminase, expression of hepatic inflammatory markers (F4/80, MCP-1, TLR4, TLR2 and IL-1β) and effector caspase (caspase 3 and 7) activation compared to HCR rats. Further, LCR rats had greater WD-induced decreases in complete FAO and mitochondrial respiratory capacity. Intrinsic aerobic capacity had no impact on WD-induced hepatic steatosis; however, rats bred for low aerobic capacity developed greater hepatic inflammation, which was associated with reduced hepatic mitochondrial FAO and respiratory capacity and increased accumulation of cholesterol esters. These results confirm epidemiological reports that aerobic capacity impacts progression of liver disease and suggest that these effects are mediated through alterations in hepatic mitochondrial function.
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Affiliation(s)
- E Matthew Morris
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Colin S McCoin
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Julie A Allen
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Michelle L Gastecki
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, USA
| | - Lauren G Koch
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
| | - Steven L Britton
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
| | - Justin A Fletcher
- Advanced Imaging Research Service, University of Texas Southwestern, Dallas, TX, USA
| | - Xiarong Fu
- Advanced Imaging Research Service, University of Texas Southwestern, Dallas, TX, USA
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA
| | - Shawn C Burgess
- Advanced Imaging Research Service, University of Texas Southwestern, Dallas, TX, USA
| | - R Scott Rector
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, USA.,Harry S. Truman Memorial Veterans Hospital-Research Service, Columbia, MO, USA
| | - John P Thyfault
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA.,Kansas City VA Medical Center-Research Service, Kansas City, MO, USA
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Porter J, Rowles JL, Fletcher JA, Zidon TM, Winn NC, McCabe L, Park YM, Perfield JW, Thyfault JP, Rector RS, Padilla J, Vieira-Potter VJ. Exercise Normalizes Dysfunctional Adipose Tissue Phenotype in FGF21-Null Mice. Med Sci Sports Exerc 2017. [DOI: 10.1249/01.mss.0000519822.07921.89] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Obata Y, Horikawa K, Takahashi T, Akieda Y, Tsujimoto M, Fletcher JA, Esumi H, Nishida T, Abe R. Oncogenic signaling by Kit tyrosine kinase occurs selectively on the Golgi apparatus in gastrointestinal stromal tumors. Oncogene 2017; 36:3661-3672. [PMID: 28192400 PMCID: PMC5500841 DOI: 10.1038/onc.2016.519] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 12/13/2016] [Accepted: 12/27/2016] [Indexed: 02/06/2023]
Abstract
Gastrointestinal stromal tumors (GISTs) are caused by gain-of-function mutations in the Kit receptor tyrosine kinase. Most primary GIST patients respond to the Kit inhibitor imatinib, but this drug often becomes ineffective because of secondary mutations in the Kit kinase domain. The characteristic intracellular accumulation of imatinib-sensitive and -resistant Kit protein is well documented, but its relationship to oncogenic signaling remains unknown. Here, we show that in cancer tissue from primary GIST patients as well as in cell lines, mutant Kit accumulates on the Golgi apparatus, whereas normal Kit localizes to the plasma membrane (PM). In imatinib-resistant GIST with a secondary Kit mutation, Kit localizes predominantly on the Golgi apparatus. Both imatinib-sensitive and imatinib-resistant Kit (Kit(mut)) become fully auto-phosphorylated only on the Golgi and only if in a complex-glycosylated form. Kit(mut) accumulates on the Golgi during the early secretory pathway, but not after endocytosis. The aberrant kinase activity of Kit(mut) prevents its export from the Golgi to the PM. Furthermore, Kit(mut) on the Golgi signals and activates the phosphatidylinositol 3-kinase–Akt (PI3K–Akt) pathway, signal transducer and activator of transcription 5 (STAT5), and the Mek–Erk pathway. Blocking the biosynthetic transport of Kit(mut) to the Golgi from the endoplasmic reticulum inhibits oncogenic signaling. PM localization of Kit(mut) is not required for its signaling. Activation of Src-family tyrosine kinases on the Golgi is essential for oncogenic Kit signaling. These results suggest that the Golgi apparatus serves as a platform for oncogenic Kit signaling. Our study demonstrates that Kit(mut)’s pathogenicity is related to its mis-localization, and may offer a new strategy for treating imatinib-resistant GISTs.
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Affiliation(s)
- Y Obata
- Division of Immunobiology, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - K Horikawa
- Division of Immunobiology, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - T Takahashi
- Department of Surgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan
| | - Y Akieda
- Division of Immunobiology, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - M Tsujimoto
- Department of Diagnostic Pathology, Osaka Police Hospital, Osaka, Osaka, Japan
| | - J A Fletcher
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - H Esumi
- Division of Clinical Research, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - T Nishida
- National Cancer Center Hospital, Chuo-ku, Tokyo, Japan
| | - R Abe
- Division of Immunobiology, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
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15
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Morris EM, Meers GME, Koch LG, Britton SL, Fletcher JA, Fu X, Shankar K, Burgess SC, Ibdah JA, Rector RS, Thyfault JP. Aerobic capacity and hepatic mitochondrial lipid oxidation alters susceptibility for chronic high-fat diet-induced hepatic steatosis. Am J Physiol Endocrinol Metab 2016; 311:E749-E760. [PMID: 27600823 PMCID: PMC5241560 DOI: 10.1152/ajpendo.00178.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 08/30/2016] [Indexed: 12/24/2022]
Abstract
Rats selectively bred for high capacity running (HCR) or low capacity running (LCR) display divergence for intrinsic aerobic capacity and hepatic mitochondrial oxidative capacity, both factors associated with susceptibility for nonalcoholic fatty liver disease. Here, we tested if HCR and LCR rats display differences in susceptibility for hepatic steatosis after 16 wk of high-fat diets (HFD) with either 45% or 60% of kcals from fat. HCR rats were protected against HFD-induced hepatic steatosis, whereas only the 60% HFD induced steatosis in LCR rats, as marked by a doubling of liver triglycerides. Hepatic complete fatty acid oxidation (FAO) and mitochondrial respiratory capacity were all lower in LCR compared with HCR rats. LCR rats also displayed lower hepatic complete and incomplete FAO in the presence of etomoxir, suggesting a reduced role for noncarnitine palmitoyltransferase-1-mediated lipid catabolism in LCR versus HCR rats. Hepatic complete FAO and mitochondrial respiration were largely unaffected by either chronic HFD; however, 60% HFD feeding markedly reduced 2-pyruvate oxidation, a marker of tricarboxylic acid (TCA) cycle flux, and mitochondrial complete FAO only in LCR rats. LCR rats displayed lower levels of hepatic long-chain acylcarnitines than HCR rats but maintained similar levels of hepatic acetyl-carnitine levels, further supporting lower rates of β-oxidation, and TCA cycle flux in LCR than HCR rats. Finally, only LCR rats displayed early reductions in TCA cycle genes after the acute initiation of a HFD. In conclusion, intrinsically high aerobic capacity confers protection against HFD-induced hepatic steatosis through elevated hepatic mitochondrial oxidative capacity.
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Affiliation(s)
- E Matthew Morris
- Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas
| | - Grace M E Meers
- Medicine and Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri
| | - Lauren G Koch
- Anesthesiology, University of Michigan, Ann Arbor, Michigan
| | | | - Justin A Fletcher
- Pharmacology and Advanced Imaging Research, University of Texas Southwestern, Dallas, Texas
| | - Xiaorong Fu
- Pharmacology and Advanced Imaging Research, University of Texas Southwestern, Dallas, Texas
| | - Kartik Shankar
- Arkansas Children's Nutrition Center and the Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Shawn C Burgess
- Pharmacology and Advanced Imaging Research, University of Texas Southwestern, Dallas, Texas
| | - Jamal A Ibdah
- Medicine and Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri
| | - R Scott Rector
- Medicine and Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri; Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Research Service, Harry S. Truman Memorial Veterans Affairs Hospital, Columbia, Missouri
| | - John P Thyfault
- Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas; Research Service, Kansas City Veterans Affairs Medical Center, Kansas City, Missourit; and
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16
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Linden MA, Fletcher JA, Meers GM, Thyfault JP, Laughlin MH, Rector RS. A return to ad libitum feeding following caloric restriction promotes hepatic steatosis in hyperphagic OLETF rats. Am J Physiol Gastrointest Liver Physiol 2016; 311:G387-95. [PMID: 27445343 PMCID: PMC5076013 DOI: 10.1152/ajpgi.00089.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/13/2016] [Indexed: 01/31/2023]
Abstract
Hyperphagic Otsuka Long-Evans Tokushima fatty (OLETF) rats develop obesity, insulin resistance, and nonalcoholic fatty liver disease (NAFLD), but lifestyle modifications, such as caloric restriction (CR), can prevent these conditions. We sought to determine if prior CR had protective effects on metabolic health and NAFLD development following a 4-wk return to ad libitum (AL) feeding. Four-week-old male OLETF rats (n = 8-10/group) were fed AL for 16 wk (O-AL), CR for 16 wk (O-CR; ∼70% kcal of O-AL), or CR for 12 wk followed by 4 wk of AL feeding (O-AL4wk). CR-induced benefit in prevention of NAFLD, including reduced hepatic steatosis, inflammation, and markers of Kupffer cell activation/number, was largely lost in AL4wk rats. These findings occurred in conjunction with a partial loss of CR-induced beneficial effects on obesity and serum triglycerides in O-AL4wk rats, but in the absence of changes in serum glucose or insulin. CR-induced increases in hepatic mitochondrial respiration remained significantly elevated (P < 0.01) in O-AL4wk compared with O-AL rats, while mitochondrial [1-(14)C]palmitate oxidation, citrate synthase activity, and β-hydroxyacyl-CoA dehydrogenase activity did not differ among OLETF groups. NAFLD development in O-AL4wk rats was accompanied by increases in the protein content of the de novo lipogenesis markers fatty acid synthase and stearoyl-CoA desaturase-1 and decreases in phosphorylated acetyl-CoA carboxylase (pACC)/ACC compared with O-CR rats (P < 0.05 for each). The beneficial effects of chronic CR on NAFLD development were largely lost with 4 wk of AL feeding in the hyperphagic OLETF rat, highlighting the importance of maintaining energy balance in the prevention of NAFLD.
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Affiliation(s)
- Melissa A. Linden
- 1Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri; ,3Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri;
| | - Justin A. Fletcher
- 1Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri; ,3Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri;
| | - Grace M. Meers
- 1Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri; ,2Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, Missouri;
| | - John P. Thyfault
- 5Department of Molecular and Integrative Physiology, Kansas University Medical Center, Kansas City, Kansas; and ,6Research Service, Kansas City Veterans Affairs Medical Center, Kansas City, Missouri
| | - M. Harold Laughlin
- 4Department of Biomedical Sciences, University of Missouri, Columbia, Missouri;
| | - R. Scott Rector
- 1Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri; ,2Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, Missouri; ,3Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri;
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Ben-Ami E, Barysauskas CM, von Mehren M, Heinrich MC, Corless CL, Butrynski JE, Morgan JA, Wagner AJ, Choy E, Yap JT, Van den Abbeele AD, Solomon SM, Fletcher JA, Demetri GD, George S. Long-term follow-up results of the multicenter phase II trial of regorafenib in patients with metastatic and/or unresectable GI stromal tumor after failure of standard tyrosine kinase inhibitor therapy. Ann Oncol 2016; 27:1794-9. [PMID: 27371698 DOI: 10.1093/annonc/mdw228] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 05/30/2016] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND This investigator-initiated trial provided the justification for the phase III GRID study resulting in worldwide regulatory approval of regorafenib as a third-line therapy for patients with metastatic gastrointestinal stromal tumors (GIST). We report the genotype analyses, long-term safety, and activity results from this initial trial of regorafenib in GIST. PATIENTS AND METHODS The trial was conducted between February 2010 and January 2014, among adult patients with metastatic GIST, after failure of at least imatinib and sunitinib. Patients received regorafenib orally, 160 mg once daily, days 1-21 of a 28-day cycle. Clinical benefit rate (CBR), defined as complete or partial response (PR), or stable disease lasting ≥16 weeks per RECIST 1.1, progression-free survival (PFS), overall survival (OS), long-term safety data, and metabolic response by functional imaging were assessed. RESULTS Thirty-three patients received at least one dose of regorafenib. The median follow-up was 41 months. CBR was documented in 25 of 33 patients [76%; 95% confidence interval (CI) 58% to 89%], including six PRs. The median PFS was 13.2 months (95% CI 9.2-18.3 months) including four patients who remained progression-free at study closure, each achieving clinical benefit for more than 3 years (range 36.8-43.5 months). The median OS was 25 months (95% CI 13.2-39.1 months). Patients whose tumors harbored a KIT exon 11 mutation demonstrated the longest median PFS (13.4 months), whereas patients with KIT/PDGFRA wild-type, non-SDH-deficient tumors experienced a median 1.6 months PFS (P < 0.0001). Long-term safety profile is consistent with previous reports; hand-foot skin reaction and hypertension were the most common reasons for dose reduction. Notably, regorafenib induced objective responses and durable benefit in SDH-deficient GIST. CONCLUSIONS Long-term follow-up of patients with metastatic GIST treated with regorafenib suggests particular benefit among patients with primary KIT exon 11 mutations and those with SDH-deficient GIST. Dose modifications are frequently required to manage treatment-related toxicities. CLINICAL TRIAL NUMBER NCT01068769.
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Affiliation(s)
- E Ben-Ami
- Center for Sarcoma and Bone Oncology, Dana Farber Cancer Institute, Boston
| | - C M Barysauskas
- Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, Boston
| | - M von Mehren
- Department of Medical Oncology, Fox Chase Cancer Center, Philadelphia
| | - M C Heinrich
- VA Portland Health Care System and Oregon Health and Science University, Portland
| | - C L Corless
- Oregon Health and Science University, Portland
| | - J E Butrynski
- Center for Sarcoma and Bone Oncology, Dana Farber Cancer Institute, Boston
| | - J A Morgan
- Center for Sarcoma and Bone Oncology, Dana Farber Cancer Institute, Boston
| | - A J Wagner
- Center for Sarcoma and Bone Oncology, Dana Farber Cancer Institute, Boston
| | - E Choy
- Division of Hematology Oncology, Massachusetts General Hospital, Boston
| | - J T Yap
- Huntsman Cancer Institute, University of Utah, Salt Lake City Department of Radiology, University of Utah, Salt Lake City
| | - A D Van den Abbeele
- Department of Imaging, Dana Farber Cancer Institute, Boston Department of Radiology
| | - S M Solomon
- Center for Sarcoma and Bone Oncology, Dana Farber Cancer Institute, Boston
| | - J A Fletcher
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston
| | - G D Demetri
- Center for Sarcoma and Bone Oncology, Dana Farber Cancer Institute, Boston Department of Ludwig Center at Dana Farber/Harvard Cancer Center and Harvard Medical School, Boston, USA
| | - S George
- Center for Sarcoma and Bone Oncology, Dana Farber Cancer Institute, Boston
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Fletcher JA, Linden MA, Sheldon RD, Meers GM, Morris EM, Butterfield A, Perfield JW, Thyfault JP, Rector RS. Fibroblast growth factor 21 and exercise-induced hepatic mitochondrial adaptations. Am J Physiol Gastrointest Liver Physiol 2016; 310:G832-43. [PMID: 27012775 PMCID: PMC4895870 DOI: 10.1152/ajpgi.00355.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 03/16/2016] [Indexed: 01/31/2023]
Abstract
Exercise stimulates hepatic mitochondrial adaptations; however, the mechanisms remain largely unknown. Here we tested whether FGF21 plays an obligatory role in exercise induced hepatic mitochondrial adaptations by testing exercise responses in FGF21 knockout mice. FGF21 knockout (FGF21-KO) and wild-type (WT) mice (11-12 wk of age) had access to voluntary running wheels for exercise (EX) or remained sedentary for 8 wk. FGF21 deficiency resulted in greater body weight, adiposity, serum cholesterol, insulin, and glucose concentrations compared with WT mice (P < 0.05). In addition, hepatic mitochondrial complete palmitate oxidation, β-hydroxyacyl-CoA dehydrogenase (β-HAD) activity, and nuclear content of PGC-1α were 30-50% lower in FGF21-KO mice compared with WT mice (P < 0.01). EX effectively lowered body weight, adiposity, serum triglycerides, free fatty acids, and insulin and normalized mitochondrial complete palmitate oxidation in the FGF21-KO mice, whereas the reduced hepatic β-HAD activity and lowered nuclear content of PGC-1α in FGF21-KO mice were not restored by EX. In addition, EX increased hepatic CPT-1α mRNA expression and ACC phosphorylation (a marker of increased AMPK activity) and reduced hepatic triacylglycerol content in both genotypes. However, FGF21-KO mice displayed a lower EX-induced increase in the mRNA expression of the hepatic gluconeogenic gene, PEPCK, compared with WT. In conclusion, FGF21 does not appear necessary for exercise-induced systemic and hepatic mitochondrial adaptations, but the increased adiposity, hyperinsulinemia, and impairments in hepatic mitochondrial function induced by FGF21 deficiency can be partially rescued by daily wheel running exercise.
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Affiliation(s)
- Justin A. Fletcher
- 1Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; ,3Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri;
| | - Melissa A. Linden
- 1Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; ,3Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri;
| | - Ryan D. Sheldon
- 1Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; ,3Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri;
| | - Grace M. Meers
- 2Department of Medicine-Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri; ,3Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri;
| | - E. Matthew Morris
- 5Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas; and
| | | | - James W. Perfield
- 4Lilly Research Laboratories, Eli Lilly and Co., Indianapolis, Indiana;
| | - John P. Thyfault
- 5Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas; and ,6Kansas City Veterans Affairs Medical Center, Research Service, Kansas, City, Missouri
| | - R. Scott Rector
- 1Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; ,2Department of Medicine-Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri; ,3Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri;
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Satapati S, Kucejova B, Duarte JAG, Fletcher JA, Reynolds L, Sunny NE, He T, Nair LA, Livingston KA, Fu X, Merritt ME, Sherry AD, Malloy CR, Shelton JM, Lambert J, Parks EJ, Corbin I, Magnuson MA, Browning JD, Burgess SC. Mitochondrial metabolism mediates oxidative stress and inflammation in fatty liver. J Clin Invest 2016; 126:1605. [PMID: 27035816 PMCID: PMC4811133 DOI: 10.1172/jci86695] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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20
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Sheldon RD, Blaize AN, Fletcher JA, Pearson KJ, Donkin S, Newcomer SC, Rector RS. Gestational exercise protects adult male offspring from high-fat diet-induced hepatic steatosis. J Hepatol 2016; 64:171-8. [PMID: 26325536 PMCID: PMC4691424 DOI: 10.1016/j.jhep.2015.08.022] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/12/2015] [Accepted: 08/17/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS Mounting evidence indicates that maternal exercise confers protection to adult offspring against various diseases. Here we hypothesized that maternal exercise during gestation would reduce high-fat diet (HFD)-induced hepatic steatosis in adult rat offspring. METHODS Following conception, pregnant dams were divided into either voluntary wheel running exercise (GE) or wheel-locked sedentary (GS) groups throughout gestation (days 4-21). Post-weaning, offspring received either normal chow diet (CD; 10% fat, 70% carbohydrate, 20% protein) or HFD (45% fat, 35% carbohydrate, and 20% protein) until sacrificed at 4- or 8-months of age. RESULTS GE did not affect offspring birth weight or litter size. HFD feeding in offspring increased weight gain, body fat percentage, and glucose tolerance test area under the curve (GTT-AUC). Male offspring from GE dams had reduced body fat percentage across all ages (p<0.05). In addition, 8-month male offspring from GE dams were protected against HFD-induced hepatic steatosis, which was associated with increased markers of hepatic mitochondrial biogenesis (PGC-1α and TFAM), autophagic potential (ATG12:ATG5 conjugation) and hepatic triacylglycerol secretion (MTTP). CONCLUSIONS The current study provides the first evidence that gestational exercise can reduce susceptibility to HFD-induced hepatic steatosis in adult male offspring.
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Affiliation(s)
- Ryan D. Sheldon
- Department of Nutrution and Exercise Physiology, University of Missouri, Columbia, MO, USA.
,Research Service-Harry S Truman Memorial VA Hospital, Columbia, MO, USA.
| | - A. Nicole Blaize
- Department of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.
| | - Justin A. Fletcher
- Department of Nutrution and Exercise Physiology, University of Missouri, Columbia, MO, USA.
,Research Service-Harry S Truman Memorial VA Hospital, Columbia, MO, USA.
| | - Kevin J. Pearson
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY
| | - Shawn Donkin
- Department of Nutrition, Purdue University, West Lafayette, IN, USA.
| | - Sean C. Newcomer
- Department of Kinesiology, California State - San Marcos, San Marcos, CA, USA.
| | - R. Scott Rector
- Department of Nutrution and Exercise Physiology, University of Missouri, Columbia, MO, USA.
,Department of Medicine, University of Missouri, Columbia, MO, USA.
,Research Service-Harry S Truman Memorial VA Hospital, Columbia, MO, USA.
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Satapati S, Kucejova B, Duarte JAG, Fletcher JA, Reynolds L, Sunny NE, He T, Nair LA, Livingston KA, Fu X, Merritt ME, Sherry AD, Malloy CR, Shelton JM, Lambert J, Parks EJ, Corbin I, Magnuson MA, Browning JD, Burgess SC. Mitochondrial metabolism mediates oxidative stress and inflammation in fatty liver. J Clin Invest 2015; 125:4447-62. [PMID: 26571396 DOI: 10.1172/jci82204] [Citation(s) in RCA: 273] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 10/08/2015] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are critical for respiration in all tissues; however, in liver, these organelles also accommodate high-capacity anaplerotic/cataplerotic pathways that are essential to gluconeogenesis and other biosynthetic activities. During nonalcoholic fatty liver disease (NAFLD), mitochondria also produce ROS that damage hepatocytes, trigger inflammation, and contribute to insulin resistance. Here, we provide several lines of evidence indicating that induction of biosynthesis through hepatic anaplerotic/cataplerotic pathways is energetically backed by elevated oxidative metabolism and hence contributes to oxidative stress and inflammation during NAFLD. First, in murine livers, elevation of fatty acid delivery not only induced oxidative metabolism, but also amplified anaplerosis/cataplerosis and caused a proportional rise in oxidative stress and inflammation. Second, loss of anaplerosis/cataplerosis via genetic knockdown of phosphoenolpyruvate carboxykinase 1 (Pck1) prevented fatty acid-induced rise in oxidative flux, oxidative stress, and inflammation. Flux appeared to be regulated by redox state, energy charge, and metabolite concentration, which may also amplify antioxidant pathways. Third, preventing elevated oxidative metabolism with metformin also normalized hepatic anaplerosis/cataplerosis and reduced markers of inflammation. Finally, independent histological grades in human NAFLD biopsies were proportional to oxidative flux. Thus, hepatic oxidative stress and inflammation are associated with elevated oxidative metabolism during an obesogenic diet, and this link may be provoked by increased work through anabolic pathways.
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Linden MA, Fletcher JA, Morris EM, Meers GM, Laughlin MH, Booth FW, Sowers JR, Ibdah JA, Thyfault JP, Rector RS. Treating NAFLD in OLETF rats with vigorous-intensity interval exercise training. Med Sci Sports Exerc 2015; 47:556-67. [PMID: 24983336 DOI: 10.1249/mss.0000000000000430] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND There is increasing use of high-intensity interval-type exercise training in the management of many lifestyle-related diseases. PURPOSE This study aimed to test the hypothesis that vigorous-intensity interval exercise is as effective as traditional moderate-intensity aerobic exercise training for nonalcoholic fatty liver disease (NAFLD) outcomes in obese, Otsuka Long-Evans Tokushima Fatty (OLETF) rats. METHODS OLETF rats (age, 20 wk; n = 8-10 per group) were assigned to sedentary (O-SED), moderate-intensity exercise training (O-MOD EX; 20 m·min(-1), 15% incline, 60 min·d(-1), 5 d·wk(-1) of treadmill running), or vigorous-intensity interval exercise training (O-VIG EX; 40 m·min(-1), 15% incline, 6 × 2.5 min bouts per day, 5 d·wk(-1) of treadmill running) groups for 12 wk. RESULTS Both MOD EX and VIG EX effectively lowered hepatic triglycerides, serum alanine aminotransferase (ALT), perivenular fibrosis, and hepatic collagen 1α1 messenger RNA (mRNA) expression (vs O-SED, P < 0.05). In addition, both interventions increased hepatic mitochondrial markers (citrate synthase activity and fatty acid oxidation) and suppressed markers of de novo lipogenesis (fatty acid synthase, acetyl coenzyme A carboxylase, Elovl fatty acid elongase 6, and steroyl CoA desaturase-1), whereas only MOD EX increased hepatic mitochondrial Beta-hydroxyacyl-CoA dehydrogenase (β-HAD) activity and hepatic triglyceride export marker apoB100 and lowered fatty acid transporter CD36 compared with O-SED. Moreover, whereas total hepatic macrophage population markers (CD68 and F4/80 mRNA) did not differ among groups, MOD EX and VIG EX lowered M1 macrophage polarization markers (CD11c, interleukin-1β, and tumor necrosis factor α mRNA) and MOD EX increased M2 macrophage marker, CD206 mRNA, compared with O-SED. CONCLUSIONS The accumulation of 15 min·d(-1) of VIG EX for 12 wk had similar effectiveness as 60 min·d(-1) of MOD EX in the management of NAFLD in OLETF rats. These findings may have important health outcome implications as we work to design better exercise training programs for patients with NAFLD.
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Affiliation(s)
- Melissa A Linden
- 1Research Service-Harry S. Truman Memorial Veterans Medical Center, Columbia, MO; 2Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO; 3Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO; 4Department of Biomedical Sciences, University of Missouri, Columbia, MO; 5Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO; 6Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO; and 7Department of Medicine, Division of Endocrinology, University of Missouri, Columbia, MO
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23
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Linden MA, Lopez KT, Fletcher JA, Morris EM, Meers GM, Siddique S, Laughlin MH, Sowers JR, Thyfault JP, Ibdah JA, Rector RS. Combining metformin therapy with caloric restriction for the management of type 2 diabetes and nonalcoholic fatty liver disease in obese rats. Appl Physiol Nutr Metab 2015; 40:1038-47. [PMID: 26394261 DOI: 10.1139/apnm-2015-0236] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Weight loss is recommended for patients with nonalcoholic fatty liver disease (NAFLD), while metformin may lower liver enzymes in type 2 diabetics. Yet, the efficacy of the combination of weight loss and metformin in the treatment of NAFLD is unclear. We assessed the effects of metformin, caloric restriction, and their combination on NAFLD in diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Male OLETF rats (age 20 weeks; n = 6-8 per group) were fed ad libitum (AL), given metformin (300 mg·kg(-1)·day(-1); Met), calorically restricted (70% of AL; CR), or calorically restricted and given metformin (CR+Met) for 12 weeks. Met lowered adiposity compared with AL but not to the same magnitude as CR or CR+Met (p < 0.05). Although only CR improved fasting insulin and glucose, the combination of CR+Met was needed to improve post-challenge glucose tolerance. All treatments lowered hepatic triglycerides, but further improvements were observed in the CR groups (p < 0.05, Met vs. CR or CR+Met) and a further reduction in serum alanine aminotransferases was observed in CR+Met rats. CR lowered markers of hepatic de novo lipogenesis (fatty acid synthase, acetyl-CoA carboxylase (ACC), and stearoyl-CoA desaturase-1 (SCD-1)) and increased hepatic mitochondrial activity (palmitate oxidation and β-hydroxyacyl CoA dehydrogenase (β-HAD) activity). Changes were enhanced in the CR+Met group for ACC, SCD-1, β-HAD, and the mitophagy marker BNIP3. Met decreased total hepatic mTOR content and inhibited mTOR complex 1, which may have contributed to Met-induced reductions in de novo lipogenesis. These findings in the OLETF rat suggest that the combination of caloric restriction and metformin may provide a more optimal approach than either treatment alone in the management of type 2 diabetes and NAFLD.
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Affiliation(s)
- Melissa A Linden
- a Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.,b Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211, USA
| | - Kristi T Lopez
- a Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.,c Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA
| | - Justin A Fletcher
- a Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.,b Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211, USA
| | - E Matthew Morris
- a Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.,c Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA
| | - Grace M Meers
- a Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.,c Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA
| | - Sameer Siddique
- a Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.,c Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA
| | - M Harold Laughlin
- e Department of Biomedical Sciences, University of Missouri, Columbia, MO 65211, USA
| | - James R Sowers
- a Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.,d Department of Medicine, Division of Endocrinology, University of Missouri, Columbia, MO 65212, USA
| | - John P Thyfault
- a Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.,b Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211, USA.,c Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA
| | - Jamal A Ibdah
- a Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.,b Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211, USA.,c Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA
| | - R Scott Rector
- a Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201, USA.,b Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211, USA.,c Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA
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Fletcher JA, Meers GM, Linden MA, Kearney ML, Morris EM, Thyfault JP, Rector RS. Impact of various exercise modalities on hepatic mitochondrial function. Med Sci Sports Exerc 2014; 46:1089-97. [PMID: 24263979 DOI: 10.1249/mss.0000000000000223] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE Hepatic mitochondrial adaptations to exercise are largely unknown. In this study, we sought to determine the effects of various exercise modalities on measures of hepatic mitochondrial function and metabolism. METHODS Male Sprague-Dawley rats were randomly assigned (n = 8-10 per group) into sedentary (SED), voluntary wheel running (VWR), VWR with food pulled during the dark cycle (VMR-OF), treadmill endurance exercise (TM-END; 30 m·min, 12% gradient, 60 min·d, 5 d·wk), or treadmill interval sprint training (TM-IST; 50 m·min, 12% gradient, 6 × 2.5 min bouts, 5 d·wk) groups for a 4-wk intervention. RESULTS Hepatic mitochondrial state 3 and maximal uncoupled respiration were significantly (P < 0.05) increased in all four exercise groups compared with SED animals. In addition, hepatic mitochondrial [1-C] pyruvate oxidation to CO2, an index of pyruvate dehydrogenase (PDH) activity, was significantly increased in VWR-OF, TM-END, and TM-IST rats (P < 0.05), whereas exercise-induced increases in [2-C] pyruvate oxidation and [1-C] palmitate oxidation to CO2 did not reach statistical significance. Hepatic mitochondrial sirtuin 3 protein content, which putatively increases activity of mitochondrial proteins, was elevated in the VWR, VWR-OF, and TM-END groups (P < 0.05). In addition, only VWR-OF animals experienced increases in hepatic cytochrome c protein content and phosphoenolpyruvate carboxykinase mRNA, whereas PGC-1α mRNA expression and phospho-CREB protein content was increased in VWR-OF and TM-END groups. CONCLUSION Four weeks of exercise training, regardless of exercise modality, significantly increased hepatic mitochondrial respiration and evoked other unique improvements in mitochondrial metabolism that do not appear to be dependent on increases in mitochondrial content.
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Affiliation(s)
- Justin A Fletcher
- 1Harry S. Truman Memorial Veterans' Hospital, Columbia, MO; 2Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO; and 3Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Missouri, Columbia, MO
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Jiang J, Boyle LJ, Mikus CR, Oberlin DJ, Fletcher JA, Thyfault JP, Hinton PS. The effects of improved metabolic risk factors on bone turnover markers after 12 weeks of simvastatin treatment with or without exercise. Metabolism 2014; 63:1398-408. [PMID: 25151031 DOI: 10.1016/j.metabol.2014.07.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 07/08/2014] [Accepted: 07/22/2014] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Emerging evidence supports an association between metabolic risk factors and bone turnover. Statins and exercise independently improve metabolic risk factors; however whether improvements in metabolic risk factor affects bone turnover is unknown. The purpose of the present study was to: 1) evaluate the relationship between metabolic risk factors and bone turnover; and 2) determine if improvements in metabolic risk factors after 12 weeks of statin treatment, exercise or the combination affect bone turnover. METHODS Fifty participants with ≥2 metabolic syndrome defining characteristics were randomly assigned to one of three groups: statin (STAT: simvastatin, 40 mg/day), exercise (EX: brisk walking and/or slow jogging, 45 minutes/day, 5 days/week), or the combination (STAT+EX). Body composition and whole body bone mineral density were measured with dual energy X-ray absorptiometry. Serum markers of bone formation (bone specific alkaline phosphatase, BAP; osteocalcin, OC), resorption (C-terminal peptide of type I collagen, CTX) and metabolic risk factors were determined. Two-factor (time, group) repeated-measures ANCOVA was used to examine changes of metabolic risk factors and bone turnover. General linear models were used to determine the effect of pre-treatment metabolic risk factors on post-treatment bone turnover marker outcomes. RESULTS Participants with ≥4 metabolic syndrome defining characteristics had lower pre-treatment OC than those with 3 or fewer. OC was negatively correlated with glucose, and CTX was positively correlated with cholesterol. STAT or STAT+EX lowered total and LDL cholesterol. The OC to CTX ratio decreased in all groups with no other significant changes in bone turnover. Higher pre-treatment insulin or body fat predicted a greater CTX reduction and a greater BAP/CTX increase. CONCLUSION Metabolic risk factors were negatively associated with bone turnover markers. Short-term statin treatment with or without exercise lowered cholesterol and all treatments had a small effect on bone turnover.
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Affiliation(s)
- Jun Jiang
- Department of Nutrition & Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA, 65211
| | - Leryn J Boyle
- Department of Nutrition & Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA, 65211
| | - Catherine R Mikus
- Department of Nutrition & Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA, 65211
| | - Douglas J Oberlin
- Department of Nutrition & Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA, 65211
| | - Justin A Fletcher
- Department of Nutrition & Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA, 65211
| | - John P Thyfault
- Department of Nutrition & Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA, 65211
| | - Pamela S Hinton
- Department of Nutrition & Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA, 65211.
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Morris EM, Jackman MR, Johnson GC, Liu TW, Lopez JL, Kearney ML, Fletcher JA, Meers GME, Koch LG, Britton SL, Rector RS, Ibdah JA, MacLean PS, Thyfault JP. Intrinsic aerobic capacity impacts susceptibility to acute high-fat diet-induced hepatic steatosis. Am J Physiol Endocrinol Metab 2014; 307:E355-64. [PMID: 24961240 PMCID: PMC4137118 DOI: 10.1152/ajpendo.00093.2014] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Aerobic capacity/fitness significantly impacts susceptibility for fatty liver and diabetes, but the mechanisms remain unknown. Herein, we utilized rats selectively bred for high (HCR) and low (LCR) intrinsic aerobic capacity to examine the mechanisms by which aerobic capacity impacts metabolic vulnerability for fatty liver following a 3-day high-fat diet (HFD). Indirect calorimetry assessment of energy metabolism combined with radiolabeled dietary food was employed to examine systemic metabolism in combination with ex vivo measurements of hepatic lipid oxidation. The LCR, but not HCR, displayed increased hepatic lipid accumulation in response to the HFD despite both groups increasing energy intake. However, LCR rats had a greater increase in energy intake and demonstrated greater daily weight gain and percent body fat due to HFD compared with HCR. Additionally, total energy expenditure was higher in the larger LCR. However, controlling for the difference in body weight, the LCR has lower resting energy expenditure compared with HCR. Importantly, respiratory quotient was significantly higher during the HFD in the LCR compared with HCR, suggesting reduced whole body lipid utilization in the LCR. This was confirmed by the observed lower whole body dietary fatty acid oxidation in LCR compared with HCR. Furthermore, LCR liver homogenate and isolated mitochondria showed lower complete fatty acid oxidation compared with HCR. We conclude that rats bred for low intrinsic aerobic capacity show greater susceptibility for dietary-induced hepatic steatosis, which is associated with a lower energy expenditure and reduced whole body and hepatic mitochondrial lipid oxidation.
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Affiliation(s)
| | - Matthew R Jackman
- Departments of Physiology and Biophysics, Medicine - Endocrinology, Diabetes, and Metabolism, University of Colorado School of Medicine, Aurora, Colorado
| | - Ginger C Johnson
- Departments of Physiology and Biophysics, Medicine - Endocrinology, Diabetes, and Metabolism, University of Colorado School of Medicine, Aurora, Colorado
| | - Tzu-Wen Liu
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri
| | - Jordan L Lopez
- Departments of Physiology and Biophysics, Medicine - Endocrinology, Diabetes, and Metabolism, University of Colorado School of Medicine, Aurora, Colorado
| | - Monica L Kearney
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri
| | - Justin A Fletcher
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri
| | - Grace M E Meers
- Department of Medicine - Gastroenterology and Hepatology, and
| | - Lauren G Koch
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan
| | - Stephen L Britton
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan
| | - R Scott Rector
- Department of Medicine - Gastroenterology and Hepatology, and Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Harry S. Truman Memorial Veterans Affairs Hospital-Research Service, Columbia, Missouri
| | - Jamal A Ibdah
- Department of Medicine - Gastroenterology and Hepatology, and Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Harry S. Truman Memorial Veterans Affairs Hospital-Research Service, Columbia, Missouri
| | - Paul S MacLean
- Anschutz Health and Wellness Center, Aurora, Colorado; and Departments of Physiology and Biophysics, Medicine - Endocrinology, Diabetes, and Metabolism, University of Colorado School of Medicine, Aurora, Colorado
| | - John P Thyfault
- Department of Medicine - Gastroenterology and Hepatology, and Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Harry S. Truman Memorial Veterans Affairs Hospital-Research Service, Columbia, Missouri;
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Linden MA, Sheldon RD, Fletcher JA, Meers GM, Harold Laughlin M, Thyfault JP, Scott Rector R. Exercise of Different Intensities Alter Hepatic mRNA Expression of M1/M2 Polarization Markers in OLETF Rats. Med Sci Sports Exerc 2014. [DOI: 10.1249/01.mss.0000496251.42643.cf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zhou S, Liu L, Li H, Eilers G, Kuang Y, Shi S, Yan Z, Li X, Corson JM, Meng F, Zhou H, Sheng Q, Fletcher JA, Ou WB. Multipoint targeting of the PI3K/mTOR pathway in mesothelioma. Br J Cancer 2014; 110:2479-88. [PMID: 24762959 PMCID: PMC4021537 DOI: 10.1038/bjc.2014.220] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/20/2014] [Accepted: 03/27/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Mesothelioma is a notoriously chemotherapy-resistant neoplasm, as is evident in the dismal overall survival for patients with those of asbestos-associated disease. We previously demonstrated co-activation of multiple receptor tyrosine kinases (RTKs), including epidermal growth factor receptor (EGFR), MET, and AXL in mesothelioma cell lines, suggesting that these kinases could serve as novel therapeutic targets. Although clinical trials have not shown activity for EGFR inhibitors in mesothelioma, concurrent inhibition of various activated RTKs has pro-apoptotic and anti-proliferative effects in mesothelioma cell lines. Thus, we hypothesised that a coordinated network of multi-RTK activation contributes to mesothelioma tumorigenesis. METHODS Activation of PI3K/AKT/mTOR, Raf/MAPK, and co-activation of RTKs were evaluated in mesotheliomas. Effects of RTK and downstream inhibitors/shRNAs were assessed by measuring mesothelioma cell viability/growth, apoptosis, activation of signalling intermediates, expression of cell-cycle checkpoints, and cell-cycle alterations. RESULTS We demonstrate activation of the PI3K/AKT/p70S6K and RAF/MEK/MAPK pathways in mesothelioma, but not in non-neoplastic mesothelial cells. The AKT activation, but not MAPK activation, was dependent on coordinated activation of RTKs EGFR, MET, and AXL. In addition, PI3K/AKT/mTOR pathway inhibition recapitulated the anti-proliferative effects of concurrent inhibition of EGFR, MET, and AXL. Dual targeting of PI3K/mTOR by BEZ235 or a combination of RAD001 and AKT knockdown had a greater effect on mesothelioma proliferation and viability than inhibition of individual activated RTKs or downstream signalling intermediates. Inhibition of PI3K/AKT was also associated with MDM2-p53 cell-cycle regulation. CONCLUSIONS These findings show that PI3K/AKT/mTOR is a crucial survival pathway downstream of multiple activated RTKs in mesothelioma, underscoring that PI3K/mTOR is a compelling target for therapeutic intervention.
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Affiliation(s)
- S Zhou
- 1] Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China [2] Department of Bioengineering, College of Biology and Chemical Engineering, Jiaxing University, Jiaxing, China
| | - L Liu
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - H Li
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - G Eilers
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Y Kuang
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - S Shi
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - Z Yan
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - X Li
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - J M Corson
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - F Meng
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - H Zhou
- Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China
| | - Q Sheng
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
| | - J A Fletcher
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - W-B Ou
- 1] Zhejiang Provincial Key Laboratory of Applied Enzymology, Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China [2] Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA [3] Department of Biochemistry and Molecular Biology, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China
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Linden MA, Fletcher JA, Morris EM, Meers GM, Kearney ML, Crissey JM, Laughlin MH, Booth FW, Sowers JR, Ibdah JA, Thyfault JP, Rector RS. Combining metformin and aerobic exercise training in the treatment of type 2 diabetes and NAFLD in OLETF rats. Am J Physiol Endocrinol Metab 2014; 306:E300-10. [PMID: 24326426 PMCID: PMC3920010 DOI: 10.1152/ajpendo.00427.2013] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Here, we sought to compare the efficacy of combining exercise and metformin for the treatment of type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) in hyperphagic, obese, type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. OLETF rats (age: 20 wk, hyperglycemic and hyperinsulinemic; n = 10/group) were randomly assigned to sedentary (O-SED), SED plus metformin (O-SED + M; 300 mg·kg(-1)·day(-1)), moderate-intensity exercise training (O-EndEx; 20 m/min, 60 min/day, 5 days/wk treadmill running), or O-EndEx + M groups for 12 wk. Long-Evans Tokushima Otsuka (L-SED) rats served as nonhyperphagic controls. O-SED + M, O-EndEx, and O-EndEx + M were effective in the management of type 2 diabetes, and all three treatments lowered hepatic steatosis and serum markers of liver injury; however, O-EndEx lowered liver triglyceride content and fasting hyperglycemia more than O-SED + M. In addition, exercise elicited greater improvements compared with metformin alone on postchallenge glycemic control, liver diacylglycerol content, hepatic mitochondrial palmitate oxidation, citrate synthase, and β-HAD activities and in the attenuation of markers of hepatic fatty acid uptake and de novo fatty acid synthesis. Surprisingly, combining metformin and aerobic exercise training offered little added benefit to these outcomes, and in fact, metformin actually blunted exercise-induced increases in complete mitochondrial palmitate oxidation and β-HAD activity. In conclusion, aerobic exercise training was more effective than metformin administration in the management of type 2 diabetes and NAFLD outcomes in obese hyperphagic OLETF rats. Combining therapies offered little additional benefit beyond exercise alone, and findings suggest that metformin potentially impairs exercise-induced hepatic mitochondrial adaptations.
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Affiliation(s)
- Melissa A Linden
- Research Service, Harry S. Truman Memorial Veterans Affairs Hospital
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Abstract
Nonalcoholic fatty liver disease (NAFLD) is now considered the most prevalent chronic liver disease, affecting over 30% of the US adult population. NAFLD is strongly linked to insulin resistance and is considered the hepatic manifestation of the metabolic syndrome. Activation of the renin-angiotensin-aldosterone system (RAAS) is known to play a role in the hypertension observed in the metabolic syndrome and also is thought to play a central role in insulin resistance and NAFLD. Angiotensin II (AngII) is considered the primary effector of the physiological outcomes of RAAS signaling, both at the systemic and local tissue level. Herein, we review data describing the potential involvement of AngII-mediated signaling at multiple levels in the development and progression of NAFLD, including increased steatosis, inflammation, insulin resistance, and fibrosis. Additionally, we present recent work on the potential therapeutic benefits of RAAS and angiotensin II signaling inhibition in rodent models and patients with NAFLD.
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Affiliation(s)
- E Matthew Morris
- Department of Internal Medicine - Division of Gastroenterology and Hepatology, University of Missouri, MO, United States; Harry S Truman Memorial Veterans Medical Center, Columbia, MO 65201, United States.
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Linden MA, Meers GM, Fletcher JA, Siddique S, Laughlin MH, Booth FW, Ibdah JA, Thyfault JP, Rector RS. Metformin, Aerobic Exercise, and the Combination in the Treatment of Type 2 Diabetes and NAFLD in OLETF rats. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1155.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Melissa A Linden
- University of Missouri and Harry S. Truman Memorial Veterans Medical CenterColumbiaMO
| | - Grace M. Meers
- University of Missouri and Harry S. Truman Memorial Veterans Medical CenterColumbiaMO
| | - Justin A. Fletcher
- University of Missouri and Harry S. Truman Memorial Veterans Medical CenterColumbiaMO
| | - Sameer Siddique
- University of Missouri and Harry S. Truman Memorial Veterans Medical CenterColumbiaMO
| | - M. Harold Laughlin
- University of Missouri and Harry S. Truman Memorial Veterans Medical CenterColumbiaMO
| | - Frank W. Booth
- University of Missouri and Harry S. Truman Memorial Veterans Medical CenterColumbiaMO
| | - Jamal A. Ibdah
- University of Missouri and Harry S. Truman Memorial Veterans Medical CenterColumbiaMO
| | - John P. Thyfault
- University of Missouri and Harry S. Truman Memorial Veterans Medical CenterColumbiaMO
| | - R. Scott Rector
- University of Missouri and Harry S. Truman Memorial Veterans Medical CenterColumbiaMO
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Fletcher JA, Meers GM, Laughlin MH, Ibdah JA, Thyfault JP, Rector RS. Modulating fibroblast growth factor 21 in hyperphagic OLETF rats with daily exercise and caloric restriction. Appl Physiol Nutr Metab 2012; 37:1054-62. [PMID: 22891896 DOI: 10.1139/h2012-091] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Chronic treatment with fibroblast growth factor 21 (FGF-21) favorably improves obesity and nonalcoholic fatty liver disease (NAFLD) outcomes; however, FGF-21 expression is paradoxically elevated in obese conditions. Here, we sought to determine the effects of obesity prevention by daily exercise (EX) vs. caloric restriction (CR) on hepatic FGF-21 in the hyperphagic, Otsuka Long-Evans Tokushima Fatty (OLETF) rat. Four-week-old male OLETF rats were randomized into groups (n = 7-8 per group) of ad libitum fed, sedentary (OLETF-SED), voluntary wheel running exercise (OLETF-EX), or CR (OLETF-CR; 70% of SED) until 40 weeks of age. Nonhyperphagic, Long-Evans Tokushima Otsuka (LETO-SED) rats served as controls. Both daily EX and CR prevented obesity and NAFLD development observed in the OLETF-SED animals. This was associated with significantly (p < 0.01) lower serum FGF-21 (~80% lower) and hepatic FGF-21 mRNA expression (~65% lower) in the OLETF-EX and OLETF-CR rats compared with the OLETF-SED rats. However, hepatic FGF-21 protein content was reduced to the greatest extent in the OLETF-EX animals (50% of OLETF-SED) and did not differ between the OLETF-SED and OLETF-CR rats. Hepatic FGF-21 signaling mediators - hepatic FGF-21 receptor 2 (FGFR2, mRNA expression), hepatic FGF-21 receptor substrate 2 (FRS2, protein content), and co-receptor β-Klotho (protein content) - were all elevated (60%-100%, ~40%, and +30%-50%, respectively) in the OLETF-EX and OLETF-CR animals compared with the OLETF-SED animals. Daily exercise and caloric restriction modulate hepatic FGF-21 and its primary signaling mediators in the hyperphagic OLETF rat. Enhanced metabolic action of FGF-21 may partially explain the benefits of exercise and caloric restriction on NAFLD outcomes.
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Affiliation(s)
- Justin A Fletcher
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65201, USA
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Affiliation(s)
- Monica L. Kearney
- Nutrition and Exercise PhysiologyUniversity of Missouri-ColumbiaColumbiaMO
| | - E. Matthew Morris
- Internal Medicine-Division of Gastroenterology and HepatologyUniversity of Missouri-ColumbiaColumbiaMO
| | - Grace M. Meers
- Internal Medicine-Division of Gastroenterology and HepatologyUniversity of Missouri-ColumbiaColumbiaMO
| | - Justin A. Fletcher
- Nutrition and Exercise PhysiologyUniversity of Missouri-ColumbiaColumbiaMO
| | - John P. Thyfault
- Nutrition and Exercise PhysiologyUniversity of Missouri-ColumbiaColumbiaMO
- Internal Medicine-Division of Gastroenterology and HepatologyUniversity of Missouri-ColumbiaColumbiaMO
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Rikhof B, van der Graaf WTA, Meijer C, Le PTK, Meersma GJ, de Jong S, Fletcher JA, Suurmeijer AJH. Abundant Fas expression by gastrointestinal stromal tumours may serve as a therapeutic target for MegaFasL. Br J Cancer 2008; 99:1600-6. [PMID: 18941456 PMCID: PMC2584951 DOI: 10.1038/sj.bjc.6604736] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Although the tyrosine kinase inhibitor imatinib has been shown to be an active agent in patients with gastrointestinal stromal tumours (GIST), complete remissions are almost never seen and most patients finally experience disease progression during their course of treatment. An alternative therapeutic option is to target death receptors such as Fas. We showed that a panel of imatinib-sensitive (GIST882) and imatinib-resistant (GIST48, GIST430 and GIST430K-) cell lines expressed Fas. MegaFasL, a recently developed hexameric form of soluble Fas ligand (FasL), appeared to be an active apoptosis-inducing agent in these cell lines. Moreover, MegaFasL potentiated the apoptotic effects of imatinib. Immunohistochemical evaluations, in 45 primary GISTs, underscored the relevance of the Fas pathway: Fas was expressed in all GISTs and was expressed strongly in 93%, whereas FasL was expressed at moderate and strong levels in 35 and 53% of GISTs, respectively. Fas and FasL expression were positively correlated in these primary GISTs, but there was no association between Fas or FasL expression and primary site, histological subtype, tumour size, mitotic index, risk classification, and KIT mutation status. The abundant immunohistochemical Fas and FasL expression were corroborated by western blot analysis. In conclusion, our data implicate Fas as a potential therapeutic target in GIST.
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Affiliation(s)
- B Rikhof
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Liegl B, Kepten I, Le C, Zhu M, Demetri GD, Heinrich MC, Fletcher CDM, Corless CL, Fletcher JA. Heterogeneity of kinase inhibitor resistance mechanisms in GIST. J Pathol 2008; 216:64-74. [PMID: 18623623 DOI: 10.1002/path.2382] [Citation(s) in RCA: 317] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Most GIST patients develop clinical resistance to KIT/PDGFRA tyrosine kinase inhibitors (TKI). However, it is unclear whether clinical resistance results from single or multiple molecular mechanisms in each patient. KIT and PDGFRA mutations were evaluated in 53 GIST metastases obtained from 14 patients who underwent surgical debulking after progression on imatinib or sunitinib. To interrogate possible resistance mechanisms across a broad biological spectrum of GISTs, inter- and intra-lesional heterogeneity of molecular drug-resistance mechanisms were evaluated in the following: conventional KIT (CD117)-positive GISTs with KIT mutations in exon 9, 11 or 13; KIT-negative GISTs; GISTs with unusual morphology; and KIT/PDGFRA wild-type GISTs. Genomic KIT and PDGFRA mutations were characterized systematically, using complementary techniques including D-HPLC for KIT exons 9, 11-18 and PDGFRA exons 12, 14, 18, and mutation-specific PCR (V654A, D820G, N822K, Y823D). Primary KIT oncogenic mutations were found in 11/14 patients (79%). Of these, 9/11 (83%), had secondary drug-resistant KIT mutations, including six (67%) with two to five different secondary mutations in separate metastases, and three (34%) with two secondary KIT mutations in the same metastasis. The secondary mutations clustered in the KIT ATP binding pocket and kinase catalytic regions. FISH analyses revealed KIT amplicons in 2/10 metastases lacking secondary KIT mutations. This study demonstrates extensive intra- and inter-lesional heterogeneity of resistance mutations and gene amplification in patients with clinically progressing GIST. KIT kinase resistance mutations were not found in KIT/PDGFRA wild-type GISTs or in KIT-mutant GISTs showing unusual morphology and/or loss of KIT expression by IHC, indicating that resistance mechanisms are fundamentally different in these tumours. Our observations underscore the heterogeneity of clinical TKI resistance, and highlight the therapeutic challenges involved in salvaging patients after clinical progression on TKI monotherapies.
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Affiliation(s)
- B Liegl
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Liegl B, Kepten I, Le C, Zhu M, Demetri GD, Heinrich MC, Fletcher CDM, Corless CL, Fletcher JA. Heterogeneity of kinase inhibitor resistance mechanisms in GIST. J Pathol 2008. [PMID: 21660972 DOI: 10.1002/path] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Most GIST patients develop clinical resistance to KIT/PDGFRA tyrosine kinase inhibitors (TKI). However, it is unclear whether clinical resistance results from single or multiple molecular mechanisms in each patient. KIT and PDGFRA mutations were evaluated in 53 GIST metastases obtained from 14 patients who underwent surgical debulking after progression on imatinib or sunitinib. To interrogate possible resistance mechanisms across a broad biological spectrum of GISTs, inter- and intra-lesional heterogeneity of molecular drug-resistance mechanisms were evaluated in the following: conventional KIT (CD117)-positive GISTs with KIT mutations in exon 9, 11 or 13; KIT-negative GISTs; GISTs with unusual morphology; and KIT/PDGFRA wild-type GISTs. Genomic KIT and PDGFRA mutations were characterized systematically, using complementary techniques including D-HPLC for KIT exons 9, 11-18 and PDGFRA exons 12, 14, 18, and mutation-specific PCR (V654A, D820G, N822K, Y823D). Primary KIT oncogenic mutations were found in 11/14 patients (79%). Of these, 9/11 (83%), had secondary drug-resistant KIT mutations, including six (67%) with two to five different secondary mutations in separate metastases, and three (34%) with two secondary KIT mutations in the same metastasis. The secondary mutations clustered in the KIT ATP binding pocket and kinase catalytic regions. FISH analyses revealed KIT amplicons in 2/10 metastases lacking secondary KIT mutations. This study demonstrates extensive intra- and inter-lesional heterogeneity of resistance mutations and gene amplification in patients with clinically progressing GIST. KIT kinase resistance mutations were not found in KIT/PDGFRA wild-type GISTs or in KIT-mutant GISTs showing unusual morphology and/or loss of KIT expression by IHC, indicating that resistance mechanisms are fundamentally different in these tumours. Our observations underscore the heterogeneity of clinical TKI resistance, and highlight the therapeutic challenges involved in salvaging patients after clinical progression on TKI monotherapies.
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Affiliation(s)
- B Liegl
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Ou WB, Zhu MJ, Demetri GD, Fletcher CDM, Fletcher JA. Protein kinase C-theta regulates KIT expression and proliferation in gastrointestinal stromal tumors. Oncogene 2008; 27:5624-34. [PMID: 18521081 DOI: 10.1038/onc.2008.177] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Oncogenic KIT or PDGFRA receptor tyrosine kinase mutations are compelling therapeutic targets in gastrointestinal stromal tumors (GISTs), and the KIT/PDGFRA kinase inhibitor, imatinib, is standard of care for patients with metastatic GIST. However, most of these patients eventually develop clinical resistance to imatinib and other KIT/PDGFRA kinase inhibitors and there is an urgent need to identify novel therapeutic strategies. We reported previously that protein kinase C-theta (PKCtheta) is activated in GIST, irrespective of KIT or PDGFRA mutational status, and is expressed at levels unprecedented in other mesenchymal tumors, therefore serving as a diagnostic marker of GIST. Herein, we characterize biological functions of PKCtheta in imatinib-sensitive and imatinib-resistant GISTs, showing that lentivirus-mediated PKCtheta knockdown is accompanied by inhibition of KIT expression in three KIT+/PKCtheta+ GIST cell lines, but not in a comparator KIT+/PKCtheta- Ewing's sarcoma cell line. PKCtheta knockdown in the KIT+ GISTs was associated with inhibition of the phosphatidylinositol-3-kinase/AKT signaling pathway, upregulation of the cyclin-dependent kinase inhibitors p21 and p27, antiproliferative effects due to G(1) arrest and induction of apoptosis, comparable to the effects seen after direct knockdown of KIT expression by KIT short-hairpin RNA. These novel findings highlight that PKCtheta warrants clinical evaluation as a potential therapeutic target in GISTs, including those cases containing mutations that confer resistance to KIT/PDGFRA kinase inhibitors.
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Affiliation(s)
- W-b Ou
- 1Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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Rezk S, Wheelock L, Fletcher JA, Oliveira AM, Keuker CP, Newburger PE, Xu B, Woda BA, Miron PM. Acute lymphocytic leukemia with eosinophilia and unusual karyotype. Leuk Lymphoma 2007; 47:1176-9. [PMID: 16840218 DOI: 10.1080/10428190500508710] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Bauer S, Duensing A, Demetri GD, Fletcher JA. KIT oncogenic signaling mechanisms in imatinib-resistant gastrointestinal stromal tumor: PI3-kinase/AKT is a crucial survival pathway. Oncogene 2007; 26:7560-8. [PMID: 17546049 DOI: 10.1038/sj.onc.1210558] [Citation(s) in RCA: 195] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Most gastrointestinal stromal tumor (GIST) patients respond to KIT inhibition with imatinib, yet will eventually exhibit resistance. Imatinib-resistance mechanisms are heterogeneous, and little is known about KIT functional roles in imatinib-resistant GIST. Biological consequences of biochemical inhibition of KIT, phosphatidyl-inositol-3-kinase (PI3-K), PLCgamma, MAPK/ERK kinase/mitogen-activated protein kinase (MEK/MAPK), mammalian target of rapamycin (mTOR) and JAK were determined by immunoblotting for protein activation, and by cell proliferation and apoptosis assays in GIST cell lines from imatinib-sensitive GIST (GIST882), imatinib-resistant GISTs (GIST430 and GIST48) and KIT-negative GIST (GIST62). KIT activation was 3- to 6-fold higher in GIST430 and GIST48 than in GIST882, whereas total KIT expression was comparable in these three GIST lines. In addition to the higher set point for KIT activation, GIST430 and GIST48 had intrinsic imatinib resistance. After treatment with 1 muM imatinib, residual KIT activation was 6- and 2.8-fold higher in GIST430 and GIST48, respectively, compared to GIST882. In all GIST lines, cell growth arrest resulted from PI3-K inhibition, and - to a lesser extent - from MEK/MAPK and mTOR inhibition. Inhibition of JAK/STAT or PLCgamma did not affect cell proliferation. Similarly, only PI3-K inhibition resulted in substantial apoptosis in the imatinib-resistant GISTs. We conclude that GIST secondary KIT mutations can be associated with KIT hyperactivation and imatinib resistance. Targeting critical downstream signaling proteins, such as PI3-K, is a promising therapeutic strategy in imatinib-resistant GISTs.
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Affiliation(s)
- S Bauer
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02155, USA.
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Zhu MJ, Ou WB, Fletcher CDM, Cohen PS, Demetri GD, Fletcher JA. KIT oncoprotein interactions in gastrointestinal stromal tumors: therapeutic relevance. Oncogene 2007; 26:6386-95. [PMID: 17452978 DOI: 10.1038/sj.onc.1210464] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Most gastrointestinal stromal tumors (GISTs) express oncogenic and constitutively active forms of the KIT or platelet-derived growth factor receptor alpha (PDGFRA) receptor tyrosine kinase proteins, and these kinase oncoproteins serve as targets for effective therapies. Given that mutant KIT oncoproteins serve crucial transforming roles in GISTs, we evaluated interactions with the KIT oncoproteins and determined signaling pathways that are dependent on KIT oncogenic activation in GISTs. Tyrosine-phosphorylated KIT oncoproteins interacted with PDGFRA, PDGFRB, phosphatidylinositol 3-kinase (PI3-K) and PKCtheta in GIST cells, and these interactions were abolished by KIT inhibition with imatinib or PKC412 or KIT RNAi. Notably, tyrosine-phosphorylated PDGFRA was prominent in frozen GIST tumors expressing KIT oncoproteins, suggesting that KIT-mediated PDGFRA phosphorylation is an efficient and biologically consequential mechanism in GISTs. Activated signaling intermediates were identified by immunoaffinity purification of tyrosine-phosphorylated proteins in GIST cells before and after treatment with KIT inhibitors, and these analyses show that GRB2, SHC, CBL and MAPK activation are largely KIT dependent in GISTs, whereas PI3-K, STAT1 and STAT3 activation are partially KIT dependent. In addition, we found that phosphorylation of several tyrosine kinase proteins - including JAK1 and EPHA4 - did not depend on KIT activation. Likewise, paxillin activation was independent of the KIT oncogenic signal. These studies identify signaling pathways that can provide both KIT-dependent and KIT-independent therapeutic synergies in GIST, and thereby highlight clinical strategies that might consolidate GIST therapeutic response to KIT/PDGFRA inhibition.
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Affiliation(s)
- M-J Zhu
- Department of Pathology, Brigham & Women's Hospital, Boston, MA 02115, USA.
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Li Y, Chang Q, Rubin BP, Fletcher C, Morgan TW, Mentzer SJ, Sugarbaker DJ, Fletcher JA, Xiao S. Insulin receptor activation in solitary fibrous tumours. J Pathol 2007; 211:550-554. [PMID: 17299733 DOI: 10.1002/path.2136] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Solitary fibrous tumours (SFTs) are known to overexpress insulin-like growth factor 2 (IGF-2). The down-stream oncogenic pathways of IGF-2, however, are not clear. Here we report uniform activation of the insulin receptor (IR) pathway in SFTs, which are mesenchymal tumours frequently associated with hypoglycaemia. Whereas the IR and its downstream signalling pathways were constitutively activated in SFTs, insulin-like growth factor 1 receptor (IGF-1R) was not expressed in these tumours. We also find that SFT cells secrete IGF-2 and proliferate in serum-free medium, consistent with an IGF-2/IR autocrine loop. The aetiological relevance of IGF-2 is supported by expression of IR-A, the IR isoform with high affinity for IGF-2, in all SFTs. Our studies suggest that IR activation plays an oncogenic role in SFTs.
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Affiliation(s)
- Y Li
- Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
| | - Q Chang
- Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
| | - B P Rubin
- Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
| | - Cdm Fletcher
- Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
| | - T W Morgan
- Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
| | - S J Mentzer
- Department of Surgery, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
| | - D J Sugarbaker
- Department of Surgery, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
| | - J A Fletcher
- Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
| | - S Xiao
- Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
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Affiliation(s)
- J A Fletcher
- Department of Zoology, University of British Columbia, 2370-6270 University Boulevard, Vancouver, BC, Canada V6T 1Z4.
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Abstract
Fatty acid synthase (FASN), a key enzyme for de novo lipogenesis, is overexpressed in many malignant tumours and is associated with aggressive biological behaviour. FASN expression and its possible relationship with more aggressive behaviour in gastrointestinal stromal tumours (GISTs) have not been addressed to date. Here, FASN expression was assessed by immunohistochemistry in 60 primary GISTs (28 low/intermediate risk and 32 high risk) and seven metastatic GISTs. Sixteen smooth muscle gastrointestinal tumours were used as controls. FASN was overexpressed in 36 of 60 GISTs (60%): in 12 of 28 (42%) low/intermediate-risk GISTs and in 24 of 32 (75%) high-risk GISTs (p<0.05). Two primary and seven metastatic GISTs and five GIST cell lines (GIST882, GIST430, GIST522, GIST62, and GIST48), analysed by western blot, showed variable FASN expression. Most metastatic samples expressed high levels of FASN protein. Additionally, seven of 60 GISTs showed a proliferation rate higher than 10% by Ki67 and all of them expressed FASN (p<0.04). Finally, proliferation and apoptosis were investigated after FASN silencing in GIST882 cells, which displayed the highest FASN expression. siRNA-mediated FASN knock-down inhibited expression of the proliferation marker cyclin A, whereas no changes in p27 and cleaved PARP expression were seen. It is concluded that FASN is preferentially overexpressed in high-risk and metastatic GISTs, and that its overexpression likely contributes to cell proliferation.
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Affiliation(s)
- S Rossi
- Department of Pathology, Regional Hospital, Treviso, Italy, and Department of Medical Oncology, Harvard Medical School, Boston, MA, USA
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Rubin BP, Singer S, Tsao C, Duensing A, Lux ML, Ruiz R, Hibbard MK, Chen CJ, Xiao S, Tuveson DA, Demetri GD, Fletcher CD, Fletcher JA. KIT activation is a ubiquitous feature of gastrointestinal stromal tumors. Cancer Res 2001; 61:8118-21. [PMID: 11719439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, and they are generally resistant to chemotherapy and radiation therapy. Most GISTs express the KIT receptor tyrosine kinase protein, and a subset of GISTs contain activating mutations within the KIT juxtamembrane region. We evaluated 48 GISTs, including 10 benign, 10 borderline, and 28 malignant cases, to determine whether KIT expression and activation are general properties of these tumors. Immunohistochemical KIT expression was demonstrated in each case. Somatic KIT mutations were found in 44 tumors (92%), of which 34 (71%) had juxtamembrane region mutations. Other GISTs had KIT mutations in the extracellular region (n = 6) and in two different regions in the tyrosine kinase domain (n = 4). Contrary to previous reports, KIT mutations were not identified preferentially in higher-grade tumors: indeed, they were found in each of 10 histologically benign GISTs. Notably, mutations in all KIT domains were associated with high-level KIT activation/phosphorylation, and KIT activation was also demonstrated in the four GISTs that lacked detectable KIT genomic and cDNA mutations. These studies underscore the role of KIT activation in GIST pathogenesis, and they suggest that activated KIT might represent a universal therapeutic target in GISTs.
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Affiliation(s)
- B P Rubin
- Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
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Vargas SO, French CA, Faul PN, Fletcher JA, Davis IJ, Dal Cin P, Perez-Atayde AR. Upper respiratory tract carcinoma with chromosomal translocation 15;19: evidence for a distinct disease entity of young patients with a rapidly fatal course. Cancer 2001; 92:1195-203. [PMID: 11571733 DOI: 10.1002/1097-0142(20010901)92:5<1195::aid-cncr1438>3.0.co;2-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Carcinoma of the upper respiratory tract is rare in childhood, and cytogenetic aberrations have not been characterized in this population. The chromosomal translocation 15;19 has been reported four times previously. All patients were young and had tumors arising in the thorax. The three reports that provide clinical follow-up all describe superior vena cava syndrome and death soon after presentation. All tumors were diagnosed as carcinoma (three undifferentiated, one mucoepidermoid), and the authors suggested thymus, lung, or germ cell origin. METHODS The authors investigated the clinical and pathologic findings in two patients with poorly differentiated carcinoma showing evidence of t(15;19). This included a 13-year-old girl with a rapidly growing epiglottic mass, leading to superior vena cava syndrome and death and a 12-year-old girl with an aggressive nasopharyngeal mass showing intracranial extension. RESULTS The laryngeal tumor was poorly differentiated, with vesicular nuclei, prominent nucleoli, extensive necrosis, and a lymphoplasmacytic infiltrate; cells were positive for cytokeratin and negative for lymphoma, melanoma, germ cell, and endocrine markers. Electron microscopy showed rare intermediate junctions and basal lamina. The nasopharyngeal tumor was poorly differentiated with areas of obvious squamous differentiation observed histologically, immunophenotypically, and ultrastructurally. Cytogenetic and fluorescent in situ hybridization studies were consistent with t(15;19)(q13;p13.1) in both cases. Both children received chemo- and radiotherapy. The first child died of disease after 36 weeks; autopsy revealed tumor in the larynx with spread to the skin/subcutis (neck and thorax) and lymph nodes (cervical, subcarinal, and pulmonary hilar). The second child developed widespread bony metastases and died of disease after 13 weeks. CONCLUSIONS In conjunction with previous reports, the authors' findings show that t(15;19) is part of a distinct clinicopathologic entity characterized by young age, midline carcinoma of the neck or upper thorax, and a rapidly fatal course. Female gender and superior vena cava syndrome are common. The histogenesis of these distinctive tumors is unknown. The authors' findings suggest origin in the upper airway, perhaps from submucosal glands.
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Affiliation(s)
- S O Vargas
- Department of Pathology, Children's Hospital, Boston, Massachusetts 02115, USA
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Abstract
Pleuropulmonary blastoma, an aggressive tumor that is emerging as a distinct entity of childhood, is characterized by mesenchymal elements (including undifferentiated blastema and often cartilaginous, rhabdomyoblastic, or fibroblastic differentiation) and epithelium-lined spaces. We investigated two patients with pleuropulmonary blastoma, a 3-year-old boy and an 11-year-old girl, both with large cystic masses replacing one lung. In both children, the post-chemotherapy resection specimens showed more maturation of rhabdomyoblasts and more nuclear pleomorphism in all mesenchymal cell lines, compared with biopsies sampled before treatment. Karyotypic analysis demonstrated gains in chromosome 8 in both cases and 17p deletion in one case. Fluorescent in situ hybridization analysis demonstrated that the chromosome 8 gains were present in all mesenchymal elements, including undifferentiated blastematous, rhabdomyoblastic, fibroblastic, and chondroblastic areas. Epithelial cells showed no chromosome 8 gains. The chromosome 8 aberrations were not appreciably different in pre- versus post-chemotherapy tissue. Our findings substantiate previous reports that polysomy of chromosome 8 is a consistent feature of pleuropulmonary blastoma. Further, they indicate that clonal proliferation in pleuropulmonary blastoma is restricted to the malignant mesenchymal elements, supporting the notion that the epithelial components of this tumor are non-neoplastic.
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Affiliation(s)
- S O Vargas
- Department of Pathology, Harvard Medical School, Boston, MA 0211 5, USA
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Steele-Perkins G, Fang W, Yang XH, Van Gele M, Carling T, Gu J, Buyse IM, Fletcher JA, Liu J, Bronson R, Chadwick RB, de la Chapelle A, Zhang X, Speleman F, Huang S. Tumor formation and inactivation of RIZ1, an Rb-binding member of a nuclear protein-methyltransferase superfamily. Genes Dev 2001; 15:2250-62. [PMID: 11544182 PMCID: PMC312773 DOI: 10.1101/gad.870101] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The retinoblastoma protein-interacting zinc finger gene RIZ (PRDM2) is a member, by sequence homology, of a nuclear protein-methyltransferase (MTase) superfamily involved in chromatin-mediated gene expression. The gene produces two protein products, RIZ1 that contains a conserved MTase domain and RIZ2 that lacks the domain. RIZ1 gene expression is frequently silenced in human cancers, and the gene is also a common target of frameshift mutation in microsatellite-unstable cancers. We now report studies of mice with a targeted mutation in the RIZ1 locus. The mutation inactivates RIZ1 but not RIZ2. These RIZ1 mutant mice were viable and fertile but showed a high incidence of diffuse large B-cell lymphomas (DLBL) and a broad spectrum of unusual tumors. RIZ1 deficiency also accelerated tumorigenesis in p53 heterozygous mutant mice. Finally, several missense mutations of RIZ1 were found in human tumor tissues and cell lines; one of these was particularly common in human DLBL tumors. These missense mutations, as well as the previously described frameshift mutation, all mapped to the MTase functional domains. All abolished the capacity of RIZ1 to enhance estrogen receptor activation of transcription. These data suggest a direct link between tumor formation and the MTase domain of RIZ1 and describe for the first time a tumor susceptibility gene among methyltransferases.
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Tuveson DA, Willis NA, Jacks T, Griffin JD, Singer S, Fletcher CD, Fletcher JA, Demetri GD. STI571 inactivation of the gastrointestinal stromal tumor c-KIT oncoprotein: biological and clinical implications. Oncogene 2001; 20:5054-8. [PMID: 11526490 DOI: 10.1038/sj.onc.1204704] [Citation(s) in RCA: 535] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2001] [Revised: 04/12/2001] [Accepted: 04/16/2001] [Indexed: 01/09/2023]
Abstract
Mutations in the c-KIT receptor occur somatically in many sporadic Gastrointestinal Stromal Tumors (GIST), and similar mutations have been identified at the germline level in kindreds with multiple GISTs. These mutations activate the tyrosine kinase activity of c-KIT and induce constitutive signaling. To investigate the function of activated c-KIT in GIST, we established a human GIST cell line, GIST882, which expresses an activating KIT mutation (K642E) in the first part of the cytoplasmic split tyrosine kinase domain. Notably, the K642E substitution is encoded by a homozygous exon 13 missense mutation, and, therefore, GIST882 cells do not express native KIT. GIST882 c-KIT protein is constitutively tyrosine phosphorylated, but tyrosine phosphorylation was rapidly and completely abolished after incubating the cells with the selective tyrosine kinase inhibitor STI571. Furthermore, GIST882 cells evidenced decreased proliferation and the onset of apoptotic cell death after prolonged incubation with STI571. Similar results were obtained after administering STI571 to a primary GIST cell culture that expressed a c-KIT exon 11 juxtamembrane mutation (K558NP). These cell-culture-based studies support an important role for c-KIT signaling in GIST and suggest therapeutic potential for STI571 in patients afflicted by this chemoresistant tumor.
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Affiliation(s)
- D A Tuveson
- MIT Cancer Center and Department of Biology, Cambridge, MA 02139, USA.
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50
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Koontz JI, Soreng AL, Nucci M, Kuo FC, Pauwels P, van Den Berghe H, Dal Cin P, Fletcher JA, Sklar J. Frequent fusion of the JAZF1 and JJAZ1 genes in endometrial stromal tumors. Proc Natl Acad Sci U S A 2001; 98:6348-53. [PMID: 11371647 PMCID: PMC33471 DOI: 10.1073/pnas.101132598] [Citation(s) in RCA: 302] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Endometrial stromal tumors are divided into three types: benign stromal nodules, endometrial stromal sarcomas, and undifferentiated endometrial sarcomas. A variety of cytogenetic abnormalities involving chromosome 7 have been reported in endometrial stromal sarcomas, including a recurrent t(7;17)(p15;q21). We have identified two zinc finger genes, which we have termed JAZF1 and JJAZ1, at the sites of the 7p15 and 17q21 breakpoints. Analyses of tumor RNA indicate that a JAZF1/JJAZ1 fusion is present in all types of endometrial stromal tumors; however, the fusion appears to be rarer among endometrial stromal sarcomas that would be considered high-grade according to certain classification schemes. These findings suggest that the less malignant endometrial stromal tumors may evolve toward more malignant types, but that some endometrial stromal sarcomas with relatively abundant mitotic activity may compose a biologically distinct group.
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MESH Headings
- Amino Acid Sequence
- Artificial Gene Fusion
- Base Sequence
- Blotting, Southern/methods
- Chromosomes, Artificial, Bacterial
- Chromosomes, Artificial, Yeast
- Chromosomes, Human, Pair 17
- Chromosomes, Human, Pair 7
- Co-Repressor Proteins
- DNA, Neoplasm
- DNA-Binding Proteins
- Endometrial Neoplasms/genetics
- Endometrial Neoplasms/pathology
- Female
- Humans
- Middle Aged
- Molecular Sequence Data
- Neoplasm Proteins/genetics
- Sarcoma, Endometrial Stromal/genetics
- Sarcoma, Endometrial Stromal/pathology
- Transcription Factors
- Translocation, Genetic
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Affiliation(s)
- J I Koontz
- Division of Molecular Oncology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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