Gene expression profiling of adipose tissue:: individual, depot-dependent, and sex-dependent variabilities

Abstract

The availability of large numbers of DNA sequences and the development of technologies to analyze the function of these sequences have allowed the simultaneous study of different interactive molecular pathways involved in development and metabolism. One of these technologies uses microarrays to analyze the expression of large numbers of genes simultaneously. The power of this technology has been demonstrated by the discovery of the developmental and cold-regulated appearance of brown adipose tissue (BAT) within the mammary gland.1 Only recently has DNA microarray technology been applied to gene expression profiling of adipose tissue. Adipose tissue is an active player in the regulation of energy homeostasis. It consists of functionally heterogeneous and specialized tissues that can store and mobilize lipids and is able to release a vast number of bioactive molecules, called adipocytokines.2 Adipose tissue metabolism and thus gene expression are greatly influenced by endogenous factors such as sex, hormones, and individual genetic makeup and by exogenous factors, of which dietary and nutrition factors are the most important. We provide an overview of the currently available data on gene expression profiling in adipose tissue, with a special focus on individual, depot-dependent, and gender-dependent variability. Further, we emphasize the need to investigate adipose tissue gene expression on an individual basis because such an investigation should help to relate individual physiologic and nutrition response profiles to gene expression profiles. This link can lead to the identification of previously unknown genetic pathways and help to establish risk profiles for individuals.