A homotrimeric adipokine (AdipoQ, apM1, GBP28, adipocyte complement related protein 30, Acrp30, 244 aa) secreted by adipocytes and involved in the control of fat metabolism and insulin sensitivity, with direct antidiabetic, antiatherogenic, and anti-inflammatory activities. It is secreted following activation of the nuclear receptor PPAR-γ. Normal serum levels are ~5–10 µg/mL, but levels are decreased in both obesity and type 2 diabetes. The serum level of adiponectin as a quantitative trait is associated with variation in the adiponectin gene and by various other loci. The C-terminal globular domain has significant homology to tumour necrosis factor and adiponectin antagonizes TNFα by negatively regulating its expression in various tissues such as liver and macrophages, and also by counteracting its effects. It may also play a role in cell growth, angiogenesis, and tissue remodelling by binding and sequestering various growth factors.
Subjects: Medicine and Health.