Fig. 1.

Adipocytokines during the development of obesity.

Adiposity is influenced by the degrees of food intake and exercise activity. Lean fat expresses markers of the M2 or “alternatively activated” macrophages. Obesity leads to recruitment and accumulation of the M1 or “classically activated” macrophages and T cells in adipose tissue. Adipocytokines including adiponectin, secreted frizzled-related protein 5 (Sfrp5) and adipolin are highly produced by lean adipose tissue. Conversely, obese fat generates a large amount of adipocytokines including leptin, TNF-α, IL-6, IL-18, PAI-1, MCP-1, angiopoietin-like protein 2 (Angptl2).