A novel functional iodothyronine analogue,
TRC150094, which has a much lower potency toward
thyroid hormone receptor (α1/β1) activation than
triiodothyronine, has been shown to be effective at reducing adiposity in rats simultaneously receiving a high-fat diet (HFD). Here, by combining metabolic, functional and proteomic analysis, we studied how the hepatic and skeletal muscle phenotypes might respond to
TRC150094 treatment in HFD-fed
overweight rats. Drug treatment increased both the liver and skeletal muscle mitochondrial oxidative capacities without altering mitochondrial efficiency. Coherently, in terms of individual respiratory in-gel activity, blue-native analysis revealed an increased activity of
complex V in the liver and of complexes II and V in tibialis muscle in TCR150094-treated animals. Subsequently, the identification of differentially expressed
proteins and the analysis of their interrelations gave an integrated view of the phenotypic/metabolic adaptations occurring in the liver and muscle
proteomes during drug treatment.
TRC150094 significantly altered the expression of several
proteins involved in key liver metabolic pathways, including
amino acid and
nitrogen metabolism, and
fructose and
mannose metabolism. The canonical pathways most strongly influenced by
TRC150094 in tibialis muscle included glycolysis and gluconeogenesis,
amino acid,
fructose and
mannose metabolism, and cell signaling. The phenotypic/metabolic influence of
TRC150094 on the liver and skeletal muscle of HFD-fed
overweight rats suggests the potential clinical application of this iodothyronine analogue in ameliorating metabolic risk parameters altered by diet regimens.