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Brunner JS, Vogel A, Lercher A, Caldera M, Korosec A, Pühringer M, Hofmann M, Hajto A, Kieler M, Garrido LQ, Kerndl M, Kuttke M, Mesteri I, Górna MW, Kulik M, Dominiak PM, Brandon AE, Estevez E, Egan CL, Gruber F, Schweiger M, Menche J, Bergthaler A, Weichhart T, Klavins K, Febbraio MA, Sharif O, Schabbauer G. The PI3K pathway preserves metabolic health through MARCO-dependent lipid uptake by adipose tissue macrophages. Nat Metab 2020; 2:1427-1442. [PMID: 33199895 DOI: 10.1038/s42255-020-00311-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 10/09/2020] [Indexed: 12/25/2022]
Abstract
Adipose tissue macrophages (ATMs) display tremendous heterogeneity depending on signals in their local microenvironment and contribute to the pathogenesis of obesity. The phosphoinositide 3-kinase (PI3K) signalling pathway, antagonized by the phosphatase and tensin homologue (PTEN), is important for metabolic responses to obesity. We hypothesized that fluctuations in macrophage-intrinsic PI3K activity via PTEN could alter the trajectory of metabolic disease by driving distinct ATM populations. Using mice harbouring macrophage-specific PTEN deletion or bone marrow chimeras carrying additional PTEN copies, we demonstrate that sustained PI3K activity in macrophages preserves metabolic health in obesity by preventing lipotoxicity. Myeloid PI3K signalling promotes a beneficial ATM population characterized by lipid uptake, catabolism and high expression of the scavenger macrophage receptor with collagenous structure (MARCO). Dual MARCO and myeloid PTEN deficiencies prevent the generation of lipid-buffering ATMs, reversing the beneficial actions of elevated myeloid PI3K activity in metabolic disease. Thus, macrophage-intrinsic PI3K signalling boosts metabolic health by driving ATM programmes associated with MARCO-dependent lipid uptake.
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Affiliation(s)
- Julia S Brunner
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Andrea Vogel
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Alexander Lercher
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Michael Caldera
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Max Perutz Laboratories, Vienna, Austria
| | - Ana Korosec
- Skin and Endothelium Research Division, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Marlene Pühringer
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Melanie Hofmann
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Alexander Hajto
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Markus Kieler
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Lucia Quemada Garrido
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Martina Kerndl
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Mario Kuttke
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | | | - Maria W Górna
- Biological and Chemical Research Centre, Department of Chemistry, University of Warsaw, Warsaw, Poland
| | - Marta Kulik
- Biological and Chemical Research Centre, Department of Chemistry, University of Warsaw, Warsaw, Poland
| | - Paulina M Dominiak
- Biological and Chemical Research Centre, Department of Chemistry, University of Warsaw, Warsaw, Poland
| | - Amanda E Brandon
- Insulin Action and Energy Metabolism Laboratory, Division of Diabetes & Metabolism, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
- Faculty of Medicine and Health, School of Medical Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Emma Estevez
- Cellular & Molecular Metabolism Laboratory, Division of Diabetes & Metabolism, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Casey L Egan
- Cellular & Molecular Metabolism Laboratory, Division of Diabetes & Metabolism, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Florian Gruber
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Martina Schweiger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Jörg Menche
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Max Perutz Laboratories, Vienna, Austria
| | - Andreas Bergthaler
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Thomas Weichhart
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics, Medical University of Vienna, Vienna, Austria
| | - Kristaps Klavins
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre, Riga Technical University, Riga, Latvia
| | - Mark A Febbraio
- Cellular & Molecular Metabolism Laboratory, Division of Diabetes & Metabolism, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Omar Sharif
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria.
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria.
| | - Gernot Schabbauer
- Institute for Vascular Biology, Center for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria.
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria.
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2
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Alexopoulos SJ, Chen SY, Brandon AE, Salamoun JM, Byrne FL, Garcia CJ, Beretta M, Olzomer EM, Shah DP, Philp AM, Hargett SR, Lawrence RT, Lee B, Sligar J, Carrive P, Tucker SP, Philp A, Lackner C, Turner N, Cooney GJ, Santos WL, Hoehn KL. Mitochondrial uncoupler BAM15 reverses diet-induced obesity and insulin resistance in mice. Nat Commun 2020; 11:2397. [PMID: 32409697 PMCID: PMC7224297 DOI: 10.1038/s41467-020-16298-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 04/23/2020] [Indexed: 12/12/2022] Open
Abstract
Obesity is a health problem affecting more than 40% of US adults and 13% of the global population. Anti-obesity treatments including diet, exercise, surgery and pharmacotherapies have so far failed to reverse obesity incidence. Herein, we target obesity with a pharmacotherapeutic approach that decreases caloric efficiency by mitochondrial uncoupling. We show that a recently identified mitochondrial uncoupler BAM15 is orally bioavailable, increases nutrient oxidation, and decreases body fat mass without altering food intake, lean body mass, body temperature, or biochemical and haematological markers of toxicity. BAM15 decreases hepatic fat, decreases inflammatory lipids, and has strong antioxidant effects. Hyperinsulinemic-euglycemic clamp studies show that BAM15 improves insulin sensitivity in multiple tissue types. Collectively, these data demonstrate that pharmacologic mitochondrial uncoupling with BAM15 has powerful anti-obesity and insulin sensitizing effects without compromising lean mass or affecting food intake.
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Affiliation(s)
- Stephanie J Alexopoulos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Sing-Young Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Amanda E Brandon
- Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, NSW, 2006, Australia
| | - Joseph M Salamoun
- Department of Chemistry and Virginia Tech Centre for Drug Discovery, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Frances L Byrne
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Christopher J Garcia
- Department of Chemistry and Virginia Tech Centre for Drug Discovery, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Martina Beretta
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Ellen M Olzomer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Divya P Shah
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Ashleigh M Philp
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Stefan R Hargett
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908, USA
| | - Robert T Lawrence
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908, USA
| | - Brendan Lee
- Biological Resources Imaging Laboratory, University of New South Wales, Sydney, NSW, 2052, Australia
| | - James Sligar
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Pascal Carrive
- Department of Anatomy, School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Simon P Tucker
- Continuum Biosciences Pty Ltd., Sydney, NSW, 2035, Australia
| | - Andrew Philp
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Carolin Lackner
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Nigel Turner
- Department of Pharmacology, School of Medical Science, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Gregory J Cooney
- Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, NSW, 2006, Australia
| | - Webster L Santos
- Department of Chemistry and Virginia Tech Centre for Drug Discovery, Virginia Tech, Blacksburg, VA, 24061, USA.
- Continuum Biosciences Pty Ltd., Sydney, NSW, 2035, Australia.
| | - Kyle L Hoehn
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908, USA.
- Continuum Biosciences Pty Ltd., Sydney, NSW, 2035, Australia.
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3
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Fazakerley DJ, Fritzen AM, Nelson ME, Thorius IH, Cooke KC, Humphrey SJ, Cooney GJ, James DE. Insulin Tolerance Test under Anaesthesia to Measure Tissue-specific Insulin-stimulated Glucose Disposal. Bio Protoc 2019; 9:e3146. [PMID: 33654891 DOI: 10.21769/bioprotoc.3146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 12/16/2018] [Accepted: 12/24/2018] [Indexed: 12/18/2022] Open
Abstract
Insulin resistance is a pathophysiological state defined by impaired responses to insulin and is a risk factor for several metabolic diseases, most notably type 2 diabetes. Insulin resistance occurs in insulin target tissues including liver, adipose and skeletal muscle. Methods such as insulin tolerance tests and hyperinsulinaemic-euglycaemic clamps permit assessment of insulin responses in specific tissues and allow the study of the progression and causes of insulin resistance. Here we detail a protocol for assessing insulin action in adipose and muscle tissues in anesthetized mice administered with insulin intravenously.
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Affiliation(s)
- Daniel J Fazakerley
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Andreas M Fritzen
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen 2200, Denmark
| | - Marin E Nelson
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Ida H Thorius
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen 2200, Denmark
| | - Kristen C Cooke
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Sean J Humphrey
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Gregory J Cooney
- Charles Perkins Centre, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - David E James
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Charles Perkins Centre, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2006, Australia
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4
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Brandon AE, Liao BM, Diakanastasis B, Parker BL, Raddatz K, McManus SA, O'Reilly L, Kimber E, van der Kraan AG, Hancock D, Henstridge DC, Meikle PJ, Cooney GJ, James DE, Reibe S, Febbraio MA, Biden TJ, Schmitz-Peiffer C. Protein Kinase C Epsilon Deletion in Adipose Tissue, but Not in Liver, Improves Glucose Tolerance. Cell Metab 2019; 29:183-191.e7. [PMID: 30318338 DOI: 10.1016/j.cmet.2018.09.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 07/16/2018] [Accepted: 09/12/2018] [Indexed: 02/02/2023]
Abstract
Protein kinase C epsilon (PKCɛ) activation in the liver is proposed to inhibit insulin action through phosphorylation of the insulin receptor. Here, however, we demonstrated that global, but not liver-specific, deletion of PKCɛ in mice protected against diet-induced glucose intolerance and insulin resistance. Furthermore, PKCɛ-dependent alterations in insulin receptor phosphorylation were not detected. Adipose-tissue-specific knockout mice did exhibit improved glucose tolerance, but phosphoproteomics revealed no PKCɛ-dependent effect on the activation of insulin signaling pathways. Altered phosphorylation of adipocyte proteins associated with cell junctions and endosomes was associated with changes in hepatic expression of several genes linked to glucose homeostasis and lipid metabolism. The primary effect of PKCɛ on glucose homeostasis is, therefore, not exerted directly in the liver as currently posited, and PKCɛ activation in this tissue should be interpreted with caution. However, PKCɛ activity in adipose tissue modulates glucose tolerance and is involved in crosstalk with the liver.
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Affiliation(s)
- Amanda E Brandon
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Bing M Liao
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Barbara Diakanastasis
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Benjamin L Parker
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Katy Raddatz
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Sophie A McManus
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Liam O'Reilly
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Erica Kimber
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | | | - Dale Hancock
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | | | - Peter J Meikle
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
| | - Gregory J Cooney
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - David E James
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Saskia Reibe
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Mark A Febbraio
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia; St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2010, Australia
| | - Trevor J Biden
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia; St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2010, Australia
| | - Carsten Schmitz-Peiffer
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia; St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2010, Australia.
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5
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Takagi H, Ikehara T, Kashiwagi Y, Hashimoto K, Nanchi I, Shimazaki A, Nambu H, Yukioka H. ACC2 Deletion Enhances IMCL Reduction Along With Acetyl-CoA Metabolism and Improves Insulin Sensitivity in Male Mice. Endocrinology 2018; 159:3007-3019. [PMID: 29931154 DOI: 10.1210/en.2018-00338] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/15/2018] [Indexed: 12/13/2022]
Abstract
Intramyocellular lipid (IMCL) accumulation in skeletal muscle greatly contributes to lipid-induced insulin resistance. Because acetyl-coenzyme A (CoA) carboxylase (ACC) 2 negatively modulates mitochondrial fatty acid oxidation (FAO) in skeletal muscle, ACC2 inhibition is expected to reduce IMCL via elevation of FAO and to attenuate insulin resistance. However, the concept of substrate competition suggests that enhanced FAO results in reduced glucose use because of an excessive acetyl-CoA pool in mitochondria. To identify how ACC2-regulated FAO affects IMCL accumulation and glucose metabolism, we generated ACC2 knockout (ACC2-/-) mice and investigated skeletal muscle metabolites associated with fatty acid and glucose metabolism, as well as whole-body glucose metabolism. ACC2-/- mice displayed higher capacity of glucose disposal at the whole-body levels. In skeletal muscle, ACC2-/- mice exhibited enhanced acylcarnitine formation and reduced IMCL levels without alteration in glycolytic intermediate levels. Notably, these changes were accompanied by decreased acetyl-CoA content and enhanced mitochondrial pathways related to acetyl-CoA metabolism, such as the acetylcarnitine production and tricarboxylic acid cycle. Furthermore, ACC2-/- mice exhibited lower levels of IMCL and acetyl-CoA even under HFD conditions and showed protection against HFD-induced insulin resistance. Our findings suggest that ACC2 deletion leads to IMCL reduction without suppressing glucose use via an elevation in acetyl-CoA metabolism even under HFD conditions and offer new mechanistic insight into the therapeutic potential of ACC2 inhibition on insulin resistance.
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Affiliation(s)
- Hiroyuki Takagi
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
| | - Tatsuya Ikehara
- Biomarker Research and Development Department, Shionogi & Co., Ltd., Osaka, Japan
| | - Yuto Kashiwagi
- Biomarker Research and Development Department, Shionogi & Co., Ltd., Osaka, Japan
| | - Kumi Hashimoto
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
| | - Isamu Nanchi
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
| | - Atsuyuki Shimazaki
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
| | - Hirohide Nambu
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
| | - Hideo Yukioka
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
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Holt LJ, Brandon AE, Small L, Suryana E, Preston E, Wilks D, Mokbel N, Coles CA, White JD, Turner N, Daly RJ, Cooney GJ. Ablation of Grb10 Specifically in Muscle Impacts Muscle Size and Glucose Metabolism in Mice. Endocrinology 2018; 159:1339-1351. [PMID: 29370381 DOI: 10.1210/en.2017-00851] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/17/2018] [Indexed: 12/14/2022]
Abstract
Grb10 is an adaptor-type signaling protein most highly expressed in tissues involved in insulin action and glucose metabolism, such as muscle, pancreas, and adipose. Germline deletion of Grb10 in mice creates a phenotype with larger muscles and improved glucose homeostasis. However, it has not been determined whether Grb10 ablation specifically in muscle is sufficient to induce hypermuscularity or affect whole body glucose metabolism. In this study we generated muscle-specific Grb10-deficient mice (Grb10-mKO) by crossing Grb10flox/flox mice with mice expressing Cre recombinase under control of the human α-skeletal actin promoter. One-year-old Grb10-mKO mice had enlarged muscles, with greater cross-sectional area of fibers compared with wild-type (WT) mice. This degree of hypermuscularity did not affect whole body glucose homeostasis under basal conditions. However, hyperinsulinemic/euglycemic clamp studies revealed that Grb10-mKO mice had greater glucose uptake into muscles compared with WT mice. Insulin signaling was increased at the level of phospho-Akt in muscle of Grb10-mKO mice compared with WT mice, consistent with a role of Grb10 as a modulator of proximal insulin receptor signaling. We conclude that ablation of Grb10 in muscle is sufficient to affect muscle size and metabolism, supporting an important role for this protein in growth and metabolic pathways.
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Affiliation(s)
- Lowenna J Holt
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Amanda E Brandon
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Lewin Small
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Eurwin Suryana
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Elaine Preston
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Donna Wilks
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Nancy Mokbel
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Chantal A Coles
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Jason D White
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
- Department of Veterinary Biosciences, Faculty of Veterinary and Agricultural Science, University of Melbourne, Parkville, Victoria, Australia
| | - Nigel Turner
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Department of Pharmacology, University of New South Wales, Sydney, New South Wales, Australia
| | - Roger J Daly
- Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Gregory J Cooney
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
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7
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Thermoneutral housing temperature regulates T-regulatory cell function and inhibits ovabumin-induced asthma development in mice. Sci Rep 2017; 7:7123. [PMID: 28769099 PMCID: PMC5540912 DOI: 10.1038/s41598-017-07471-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 06/27/2017] [Indexed: 12/12/2022] Open
Abstract
The change in ambient temperature is one of the risk factors for the aggravation of bronchial asthma (BA). Yet, whether the ambient temperature influences the immune functions associated with allergic asthma remains unknown. In this study, we treated asthmatic mice with standard temperature (ST, 20 °C) or thermoneutral temperature (TT, 30 °C). The results showed that the airway inflammatory cell counts in bronchoalveolar lavage fluid (BALF) and airway hyperresponsiveness (AHR) were significantly reduced in the mice treated with TT as compared with the mice treated with ST. The imbalance of Th1/Th2 response in the lung was improved following housing the mice at TT. In addition, the pulmonary Treg cells were increased in asthmatic mice after TT treatment. The temperature stress (29 °C and 41 °C) drove naïve CD4T cells towards Th2 cells. Our data demonstrate that the change of ambient temperature was a risk factor to aggravate experimental asthma.
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