Release of Inflammatory Mediators by Human Adipose Tissue Is Enhanced in Obesity and Primarily by the Nonfat Cells: A Review

Figure 5

The relationship between adipokine release and paracrine signaling in human adipose tissue. The adipokines are divided into those released by fat cells [leptin, FABP-4, adiponectin, and GPX-3] and those by nonfat cells in adipose tissue [IL-6, IL-8, IL-10, ACE, PAI-1, ICAM-1, TNF$\alpha$, TGF$\beta$1, and omentin/intelectin]. Adipokines shown in black are those whose circulating levels are elevated in obesity as well as their release by incubated human adipose tissue explants. Circulating levels of adiponectin and GPX-3 are shown in blue since they are not elevated in obesity. Omentin/intelectin is shown as being secreted by the endothelial cells of the blood vessels of omental but not subcutaneous fat [108]. The arrows depict possible targets of the adipokines as the other cells in adipose tissue, as well as vascular smooth muscle cells (VSMC) and endothelial cells in the blood vessel walls plus release into the circulation (lumen of blood vessel).