Gene expression profiling in whole blood identifies distinct biological pathways associated with obesity.

Background: Obesity is reaching epidemic proportions and represents a significant risk factor for cardiovascular disease, diabetes, and cancer.

Methods: To explore the relationship between increased body mass and gene expression in blood, we conducted whole-genome expression profiling of whole blood from seventeen obese and seventeen well matched lean subjects. Gene expression data was analyzed at the individual gene and pathway level and a preliminary assessment of the predictive value of blood gene expression profiles in obesity was carried out.

Peroxisome proliferator-activated receptor gamma 2 and acyl-CoA synthetase 5 polymorphisms influence diet response.

Peroxisome proliferator-activated receptor gamma (PPARgamma) and its response gene, Acyl CoA synthetase 5 (ACSL5), which has an important role in fatty acid metabolism, may affect weight loss in response to caloric restriction. Therefore, we aimed to determine whether these genes were involved in the interindividual response to dietary treatment. Genotypic/phenotypic comparisons were made between selected obese women from the quintiles losing the most (diet responsive, n = 74) and the quintiles losing the least (diet-resistant, n = 67) weight in the first 6 weeks of a 900-kcal formula diet.

Tissue expression profiling using real-time PCR.

The recent development of real-time PCR allows for the rapid and accurate quantitation of gene expression in cells and tissues. Real-time PCR instrumentation is designed for the simultaneous quantitation of gene expression from a few samples up to 384 samples. The normal tissue expression profile of a gene can provide useful insights into its potential role in normal physiological processes.