Accumulation of advanced glycation end-products and activation of the SCAP/SREBP Lipogenetic pathway occur in diet-induced obese mouse skeletal muscle

PLoS One. 2015 Mar 9;10(3):e0119587. doi: 10.1371/journal.pone.0119587. eCollection 2015.

Abstract

Aim of this study was to investigate whether advanced glycation end-products (AGEs) accumulate in skeletal myofibers of two different animal models of diabesity and whether this accumulation could be associated to myosteatosis. Male C57Bl/6j mice and leptin-deficient ob/ob mice were divided into three groups and underwent 15 weeks of dietary manipulation: standard diet-fed C57 group (C57, n = 10), high-fat high-sugar diet-fed C57 group (HFHS, n = 10), and standard diet-fed ob/ob group (OB/OB, n = 8). HFHS mice and OB/OB mice developed glycometabolic abnormalities in association with decreased mass of the gastrocnemius muscle, fast-to-slow transition of muscle fibers, and lipid accumulation (that occurred preferentially in slow compared to fast fibers). Moreover, we found in muscle fibers of HFHS and OB/OB mice accumulation of AGEs that was preferential for the lipid-accumulating cells, increased expression of the lipogenic pathway SCAP/SREBP, and co-localisation between AGEs and SCAP-(hyper)expressing cells (suggestive for SCAP glycosylation). The increased expression of the SCAP/SREBP lipogenic pathway in muscle fibers is a possible mechanism underlying lipid accumulation and linking myosteatosis to muscle fiber atrophy and fast-to-slow transition that occur in response to diabesity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diet, High-Fat / adverse effects*
  • Glycation End Products, Advanced / blood*
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Lipogenesis*
  • Membrane Proteins / metabolism
  • Mice, Inbred C57BL
  • Muscle, Skeletal / metabolism*
  • Myosin Heavy Chains / metabolism
  • Obesity / blood*
  • Obesity / etiology
  • Sterol Regulatory Element Binding Proteins / metabolism

Substances

  • Glycation End Products, Advanced
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • SREBP cleavage-activating protein
  • Sterol Regulatory Element Binding Proteins
  • Myosin Heavy Chains

Grants and funding

This study was supported by the bank foundation “Fondazione CARIPLO” of Milano, Italy (Project: “Steroid myopathy: Molecular, Histopathological, and Electrophysiological Characterization”) and by a grant (ex 60%) from the University of Turin. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.