Microarray skeletal muscle PPARalpha overexpressing mice. Mus musculus

This experiment was conducted to identify target genes of the peroxisome proliferator-activated receptor alpha (PPARa) in skeletal muscle of transgenic mice that overexpressed PPARa. The following abstract from the published manuscript describes the major findings of this work. A potential link between muscle peroxisome proliferator- activated receptor-alpha signaling and obesity-related diabetes.Finck BN, Bernal-Mizrachi C, Han DH, Coleman T, Sambandam N, LaRiviere LL, Holloszy JO, Semenkovich CF, Kelly DP. The role of the peroxisome proliferator-activated receptor-alpha (PPARalpha) in the development of insulin-resistant diabetes was evaluated using gain- and loss-of-function approaches. Transgenic mice overexpressing PPARalpha in muscle (MCK-PPARalpha mice) developed glucose intolerance despite being protected from diet-induced obesity. Conversely, PPARalpha null mice were protected from diet-induced insulin resistance in the context of obesity. In skeletal muscle, MCK-PPARalpha mice exhibited increased fatty acid oxidation rates, diminished AMP-activated protein kinase activity, and reduced insulin-stimulated glucose uptake without alterations in the phosphorylation status of key insulin-signaling proteins. These effects on muscle glucose uptake involved transcriptional repression of the GLUT4 gene. Pharmacologic inhibition of fatty acid oxidation or mitochondrial respiratory coupling prevented the effects of PPARalpha on GLUT4 expression and glucose homeostasis. These results identify PPARalpha-driven alterations in muscle fatty acid oxidation and energetics as a potential link between obesity and the development of glucose intolerance and insulin resistance. Keywords: genetic modification Overall design: RNA from two wild-type (non-transgenic (NTG)) and two PPARalpha overexpressing (MCK-PPARa) mice was analyzed. Two replicates of each are provided.