Regulation of inflammation-related genes in human adipose tissue

The identification of a moderate increase in circulating inflammatory factors in obese subjects, the description of changes in inflammatory gene expression in adipose tissue (AT) and the discovery that macrophage cells infiltrate AT are observations contributing to the concept that human obesity is a chronic inflammatory illness. This concept has led to some revision of the physiopathology of obesity and of its related metabolic and cardiovascular co-morbidities. Low-grade inflammation in the AT and the subsequent production of specific biomarkers could actually link expanded fat mass to obesity complications. This review aims at providing an overview of the current knowledge brought up by human gene expression studies, notably those performed on a large scale in AT depots. The regulation of specific biomarkers related to inflammation and putative new candidates (i.e. cathepsins and serum amyloid A) is discussed in the context of weight loss programmes based on calorie restriction and physical exercise. The foreseen clinical and technological challenges are also summarized.