Effect of high‐fat diet on the expression of proteins in muscle, adipose tissues, and liver of C57BL/6 mice

Abstract

In the present study, the effect of a high fat diet on the expression of proteins in insulin target tissues was analyzed using a proteomic approach. Gastrocnemius muscle, white and brown adipose tissue, and liver were taken from C57BL/6 mice either fed on a high-fat or a chow diet. Expression levels of approximately 10 000 polypeptides for all the four tissues were assessed by two-dimensional gel electrophoresis (2-DE). Computer-assisted image analysis allowed the detection of 50 significantly (p < 0.05) differentially expressed proteins between obese and lean mice. Interestingly, more than half of these proteins were detected in the brown adipose tissue. The differentially expressed proteins were identified by tandem mass spectrometry. Several stress and redox proteins were modulated in response to the high-fat diet. A key glycolytic enzyme was found to be downregulated in adipose tissues and muscle, suggesting that at elevated plasma fatty acid concentrations, fatty acids compete with glucose as an oxidative fuel source. Furthermore, in brown adipose tissue there were significant changes in mitochondrial enzymes involved in the Krebs tricarboxylic acid (TCA) cycle and in the respiratory chain in response to the high-fat diet. The brown adipose tissue is an energy-dissipating tissue. Our data suggest that the high-fat diet treated mice were increasing energy expenditure to defend against weight gain.

Proteomics in diabetes research

“…In order to detect markers of high fat diet and insulin resistance Schmid et al performed an interesting 2DGE study (Schmid, et al 2004). Muscle, white and brown adipose tissue and liver were taken from normal mice fed a high fat or a normal chow diet.…”

Short Communication Differential expression analysis of porcine MDH1, MDH2 and ME1 genes in adipose tissues

“…ME1 promotes the release of acetyl-coenzyme A and NADPH from the mitochondria into the cytosol for de novo fatty acid biosynthesis. In addition, previous studies have indicated that MDH1, MDH2 and ME1 are associated with type II diabetes (Schmid et al, 2004;Zhong et al, 2010), and the synthesis and secretion of lipids (Bourneuf et al, 2006).…”

“…MDH1 and MDH2 are involved in de novo lipid synthesis by providing extramitochondrial reducing equivalents from the oxidation of malate (Schmid et al, 2004;Bourneuf et al, 2006). ME1 (malic enzyme), an NADP-dependent lipogenic enzyme, is involved in the conversion of L-malate to pyruvate.…”

Characterization of the Human Visceral Adipose Tissue Secretome

“…To date, no studies have been published on the adipose tissue secretome. Several studies investigated the human (10), mouse (11)(12)(13)(14), and rat (15) adipose tissue proteome, mostly using a two-dimensional gel electrophoresis approach. Celis et al (16) analyzed the human mammary adipose tissue proteome.…”