[The role of peroxisome proliferator-activated receptors γ (PPARγ) in obesity and insulin resistance].

Obesity, defined as abnormal or excessive fat accumulation, is currently believed to be a major public health problem worldwide. Over the past 20 years, the prevalence of obesity has increased rapidly in both industrialized and developing countries, resulting in a considerably increased risk of type 2 diabetes mellitus (T2DM) and metabolic syndrome. Although the exact pathophysiological mechanisms underlying these diseases remain unclear, clinical and epidemiological studies support the existence of a relationship between obesity-induced inflammation and insulin resistance linked with the development and progression of metabolic diseases. Adipokines, produced and released by adipose tissue, are considered as factors linking obesity-induced inflammation with insulin resistance, and their regulation through peroxisome proliferator-activated receptors γ (PPARγ also known as NR1C3) is essential in these processes. PPARγ are transcriptional factors belonging to the ligand-activated nuclear receptor superfamily which directly regulate the expression of a large number of genes involved in adipocyte differentiation, lipid and carbohydrate metabolism as well as adipokine synthesis; thereby they are implicated in various metabolic disorders, including obesity, insulin resistance, dyslipidemia, and hypertension. This review summarizes the current literature on a functional relationship of PPARγ with obesity and insulin resistance and, moreover, highlights the significance of synthetic ligands of these receptors in the mentioned metabolic disorders.