Figure 5. The Adipocyte Secretome. Fat cells express and release numerous protein, lipid, and nucleic acid factors that can act on other nearby or distant tissues within the body in a paracrine or endocrine manner. Leptin, adiponectin, and resistin are highlighted here because they are exclusively secreted from mouse adipocytes, while the other factors can also be secreted from other cell types. The arrow-headed line representing secretion of resistin is dashed since in humans, macrophages, and not adipocytes, primarily produce this adipokine. Abbreviations are RBP4 – retinol binding protein 4, BMPs – bone morphogenetic proteins, PAI-1 – plasminogen activator inhibitor 1, miRNA – microRNA, FFA – free fatty acid, FAHFA – fatty acid esters of hydroxyl fatty acids, PAHSA – palmitic-acid-hydroxy-steric-acid, FGF21 – fibroblast growth factor 21.