Role of Inflammatory Cytokines, Growth Factors and Adipokines in Adipogenesis and Insulin Resistance

Obesity, manifested by increased adiposity, represents a main cause of morbidity in the developed countries, causing increased risk of insulin resistance and type 2 diabetes mellitus. Recruitment of macrophages and activation of innate immunity represent the initial insult, which can be further exacerbated through secretion of chemokines and adipocytokines from activated macrophages and other cells within the adipose tissue. These events can impact adipogenesis, causing dysfunction of the adipose tissue and increased risk of insulin resistance. Various factors mediate adiposity and related insulin resistance including inflammatory and non-inflammatory factors such as pro and anti-inflammatory cytokines, adipokines and growth factors. In this review we will discuss the role of these factors in adipogenesis and development of insulin resistance and type 2 diabetes mellitus in the context of obesity. Understanding the molecular mechanisms that mediate adipogenesis and insulin resistance could help the development of novel therapeutic strategies for individuals at higher risk of insulin resistance and type 2 diabetes mellitus.