Targeting PPARs in metabolic risk management: A pharmacological and nutritional approach

Abstract

Gene expression profiling can be used to understand the effects of external factors on the metabolic state or condition of specific target tissues. In humans, such studies are complicated by the inaccessibility of these tissues. Therefore, blood cells are used as a surrogate, because blood is more readily accessible. Blood cells circulate through the body and may serve as sentinels, which pick up physiological and pathological changes and capture these changes by altering their transcriptome. This characteristic of blood cells is interesting to understand underlying mechanisms and to identify transcriptional biomarkers of responses to external stimuli, such as nutrition, pharma, toxicological agents, and exercise. In this way, it may be possible to detect metabolic disturbances before a clinical event occurs. Furthermore, gene expression profiling in blood cells may also provide biomarkers for disease diagnosis, disease progression and survival, and the effectiveness of disease treatment. However, more information is needed before it will be possible to widely implement the use of gene expression profiling in blood cells into clinical practice. Little is known, for example, about interand intraindividual variation in blood cell gene expression. Furthermore, sample processing and the resulting complex mixture of cell types affect the gene expression profile, independent of the research question. The purpose of this review is to provide an overview of the use of gene expression profiles in blood cells, with emphasis on the use of Peripheral Blood Mononuclear Cells (PBMCs), and to discuss the applicability of these expression profiles to detect gene expression changes reflecting the condition of specific target tissues and metabolic changes.