High fat diet-induced changes in mouse muscle mitochondrial phospholipids do not impair mitochondrial respiration despite insulin resistance.

Background: Type 2 diabetes mellitus and muscle insulin resistance have been associated with reduced capacity of skeletal muscle mitochondria, possibly as a result of increased intake of dietary fat. Here, we examined the hypothesis that a prolonged high-fat diet consumption (HFD) increases the saturation of muscle mitochondrial membrane phospholipids causing impaired mitochondrial oxidative capacity and possibly insulin resistance.

Methodology: C57BL/6J mice were fed an 8-week or 20-week low fat diet (10 kcal%; LFD) or HFD (45 kcal%).

An 8-week high-fat diet induces obesity and insulin resistance with small changes in the muscle transcriptome of C57BL/6J mice.

Background: Skeletal muscle is responsible for most of the insulin-stimulated glucose uptake and metabolism. Therefore, it plays an important role in the development of insulin resistance, one of the characteristics of the metabolic syndrome (MS). As the prevalence of the MS is increasing, there is an urgent need for more effective intervention strategies.

The embryonic genes Dkk3, Hoxd8, Hoxd9 and Tbx1 identify muscle types in a diet-independent and fiber-type unrelated way.

Background: The mouse skeletal muscle is composed of four distinct fiber types that differ in contractile function, number of mitochondria and metabolism. Every muscle type has a specific composition and distribution of the four fiber types. To find novel genes involved in specifying muscle types, we used microarray analysis to compare the gastrocnemius with the quadriceps from mice fed a low fat diet (LFD) or high fat diet (HFD) for 8 weeks.

Adipophilin protein expression in muscle--a possible protective role against insulin resistance.

Adipophilin is a 50 kDa protein that belongs to the PAT family (perilipin, adipophilin, TIP47, S3-12 and OXPAT), which comprises proteins involved in the coating of lipid droplets. Little is known about the functional role of adipophilin in muscle. Using the C2C12 cell line as a model, we demonstrate that palmitic acid-treated cells highly express the adipophilin protein in a dose-dependent way.