Figure 6
From: Mechanism of Interleukin-4 Reducing Lipid Deposit by Regulating Hormone-Sensitive Lipase
Molecular model of IL-4 regulating HSL in adipocytes. IL-4 increases cAMP in adipocytes, then the increased cAMP enhances PKA activity and subsequent phosphorylation of HSL and perilipin. HSL phosphorylated by PKA starts to translocate from cytoplasm to the surface of lipid droplets and degrades triacylglycerol. IL-4 boosts HSL phosphorylation/translocation in the presence of isoproterenol stimulation. After being phosphorylated, perilipin also promotes lipolysis through the interaction with p-HSL. In conclusion, IL-4 promotes lipolysis by enhancing HSL activity through cAMP/PKA pathway, the major route leading to lipolysis.
