FIGURE 2.

Insulin effects on the sebaceous gland. Insulin binding to IR/IGF-1R triggers the PI3K/Akt pathway and the critical downstream element mTORC1, which in turn activates the key lipogenic transcription factor SREBP1 and induces hyperproliferation. Moreover, insulin signaling enhances androgen synthesis as well as inflammatory response. A high glycemic diet and a sebocyte low differentiation grade exacerbate insulin stimulus. TG, triglycerides; FFA, free fatty acids; WE, wax esters; CE, cholesterol esters; CH, cholesterol. Parts of Figure 2 were drawn using images from Servier Medical Art, provided by Servier, licensed under a Creative Commons Attribution 3.0 unported license.