1
|
Huang-Doran I, Tomlinson P, Payne F, Gast A, Sleigh A, Bottomley W, Harris J, Daly A, Rocha N, Rudge S, Clark J, Kwok A, Romeo S, McCann E, Müksch B, Dattani M, Zucchini S, Wakelam M, Foukas LC, Savage DB, Murphy R, O'Rahilly S, Barroso I, Semple RK. Insulin resistance uncoupled from dyslipidemia due to C-terminal PIK3R1 mutations. JCI Insight 2016; 1:e88766. [PMID: 27766312 PMCID: PMC5070960 DOI: 10.1172/jci.insight.88766] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [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: 12/23/2022] Open
Abstract
Obesity-related insulin resistance is associated with fatty liver, dyslipidemia, and low plasma adiponectin. Insulin resistance due to insulin receptor (INSR) dysfunction is associated with none of these, but when due to dysfunction of the downstream kinase AKT2 phenocopies obesity-related insulin resistance. We report 5 patients with SHORT syndrome and C-terminal mutations in PIK3R1, encoding the p85α/p55α/p50α subunits of PI3K, which act between INSR and AKT in insulin signaling. Four of 5 patients had extreme insulin resistance without dyslipidemia or hepatic steatosis. In 3 of these 4, plasma adiponectin was preserved, as in insulin receptor dysfunction. The fourth patient and her healthy mother had low plasma adiponectin associated with a potentially novel mutation, p.Asp231Ala, in adiponectin itself. Cells studied from one patient with the p.Tyr657X PIK3R1 mutation expressed abundant truncated PIK3R1 products and showed severely reduced insulin-stimulated association of mutant but not WT p85α with IRS1, but normal downstream signaling. In 3T3-L1 preadipocytes, mutant p85α overexpression attenuated insulin-induced AKT phosphorylation and adipocyte differentiation. Thus, PIK3R1 C-terminal mutations impair insulin signaling only in some cellular contexts and produce a subphenotype of insulin resistance resembling INSR dysfunction but unlike AKT2 dysfunction, implicating PI3K in the pathogenesis of key components of the metabolic syndrome. C-terminal mutations in human PIK3R1 are associated with severe insulin resistance in the absence of dyslipidemia or hepatic steatosis.
Collapse
Affiliation(s)
- Isabel Huang-Doran
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom.,The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Patsy Tomlinson
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom.,The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Felicity Payne
- Metabolic Disease Group, Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Alexandra Gast
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom.,The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Alison Sleigh
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom.,National Institute for Health Research/Wellcome Trust Clinical Research Facility, Cambridge, United Kingdom
| | - William Bottomley
- Metabolic Disease Group, Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Julie Harris
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom.,The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Allan Daly
- Metabolic Disease Group, Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Nuno Rocha
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom.,The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Simon Rudge
- Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom
| | - Jonathan Clark
- Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom
| | - Albert Kwok
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom.,The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Stefano Romeo
- Department of Molecular and Clinical Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.,Clinical Nutrition Unit, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Emma McCann
- Department of Clinical Genetics, Glan Clwyd Hospital, Rhyl, United Kingdom
| | - Barbara Müksch
- Department of Pediatrics, Children's Hospital, Cologne, Germany
| | - Mehul Dattani
- Section of Genetics and Epigenetics in Health and Disease, Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, United Kingdom
| | - Stefano Zucchini
- Pediatric Endocrine Unit, S.Orsola-Malpighi Hospital, Bologna, Italy
| | - Michael Wakelam
- Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom
| | - Lazaros C Foukas
- Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - David B Savage
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom.,The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Rinki Murphy
- Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Stephen O'Rahilly
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom.,The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Inês Barroso
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom.,The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom.,Metabolic Disease Group, Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Robert K Semple
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom.,The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| |
Collapse
|