University of Massachusetts Medical School Faculty Publications

UMMS Affiliation

Department of Medicine, Division of Endocrinology, Metabolism, and Diabetes; UMass Metabolic Network

Publication Date

4-1-2016

Document Type

Article

Disciplines

Cellular and Molecular Physiology | Endocrinology

Abstract

The phosphatidylinositol 3-kinase (PI3K) signaling pathway is central to the action of insulin and many growth factors. Heterozygous mutations in the gene encoding the p85alpha regulatory subunit of PI3K (PIK3R1) have been identified in patients with SHORT syndrome - a disorder characterized by short stature, partial lipodystrophy, and insulin resistance. Here, we evaluated whether SHORT syndrome-associated PIK3R1 mutations account for the pathophysiology that underlies the abnormalities by generating knockin mice that are heterozygous for the Pik3r1Arg649Trp mutation, which is homologous to the mutation found in the majority of affected individuals. Similar to the patients, mutant mice exhibited a reduction in body weight and length, partial lipodystrophy, and systemic insulin resistance. These derangements were associated with a reduced capacity of insulin and other growth factors to activate PI3K in liver, muscle, and fat; marked insulin resistance in liver and fat of mutation-harboring animals; and insulin resistance in vitro in cells derived from these mice. In addition, mutant mice displayed defective insulin secretion and GLP-1 action on islets in vivo and in vitro. These data demonstrate the ability of this heterozygous mutation to alter PI3K activity in vivo and the central role of PI3K in insulin/growth factor action, adipocyte function, and glucose metabolism.

Rights and Permissions

Citation: J Clin Invest. 2016 Apr 1;126(4):1401-12. doi: 10.1172/JCI84005. Epub 2016 Mar 14. Link to article on publisher's site

Comments

Publisher PDF posted as allowed by the publisher's author rights policy at http://content-assets.jci.org/admin/forms/jcicopyright.pdf.

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

The Journal of clinical investigation

PubMed ID

26974159

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