Tissue-specific expression of Sprouty1 in mice protects against high-fat diet-induced fat accumulation, bone loss and metabolic dysfunction

Br J Nutr. 2012 Sep 28;108(6):1025-33. doi: 10.1017/S0007114511006209. Epub 2011 Dec 6.

Abstract

We recently characterised Sprouty1 (Spry1), a growth factor signalling inhibitor as a regulator of marrow progenitor cells promoting osteoblast differentiation at the expense of adipocytes. Adipose tissue-specific Spry1 expression in mice resulted in increased bone mass and reduced body fat, while conditional knockout of Spry1 had the opposite effect with decreased bone mass and increased body fat. Because Spry1 suppresses normal fat development, we tested the hypothesis that Spry1 expression prevents high-fat diet-induced obesity, bone loss and associated lipid abnormalities, and demonstrate that Spry1 has a long-term protective effect on mice fed a high-energy diet. We studied diet-induced obesity in mice with fatty acid binding promoter-driven expression or conditional knockout of Spry1 in adipocytes. Phenotyping was performed by whole-body dual-energy X-ray absorptiometry, microCT, histology and blood analysis. In conditional Spry1-null mice, a high-fat diet increased body fat by 40 %, impaired glucose regulation and led to liver steatosis. However, overexpression of Spry1 led to 35 % (P < 0·05) lower body fat, reduced bone loss and normal metabolic function compared with single transgenics. This protective phenotype was associated with decreased circulating insulin (70 %) and leptin (54 %; P < 0·005) compared with controls on a high-fat diet. Additionally, Spry1 expression decreased adipose tissue inflammation by 45 %. We show that conditional Spry1 expression in adipose tissue protects against high-fat diet-induced obesity and associated bone loss.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Adipose Tissue / immunology
  • Adipose Tissue / metabolism*
  • Adipose Tissue / pathology
  • Adiposity
  • Animals
  • Bone Resorption / etiology
  • Bone Resorption / metabolism
  • Bone Resorption / pathology
  • Bone Resorption / prevention & control*
  • Bone and Bones / immunology
  • Bone and Bones / metabolism
  • Bone and Bones / pathology
  • Crosses, Genetic
  • Diet, High-Fat / adverse effects*
  • Fatty Liver / etiology
  • Fatty Liver / metabolism
  • Fatty Liver / pathology
  • Fatty Liver / prevention & control*
  • Glucose Intolerance / etiology
  • Glucose Intolerance / metabolism
  • Glucose Intolerance / pathology
  • Glucose Intolerance / prevention & control*
  • Integrases / genetics
  • Integrases / metabolism
  • Lipid Metabolism
  • Liver / immunology
  • Liver / metabolism
  • Liver / pathology
  • Macrophages / immunology
  • Macrophages / metabolism
  • Macrophages / pathology
  • Membrane Proteins / biosynthesis
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Obesity / etiology
  • Obesity / metabolism
  • Obesity / pathology
  • Obesity / prevention & control*
  • Organ Specificity
  • Phosphoproteins / biosynthesis
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Membrane Proteins
  • Phosphoproteins
  • Recombinant Proteins
  • Spry1 protein, mouse
  • Cre recombinase
  • Integrases