Hepatic insulin signaling and glycogen synthesis machinery

The hepatic insulin signaling and glycogen synthesis machinery is a complex network of proteins in the liver responsible for regulating glucose homeostasis in response to insulin (Petersen & Shulman, 2018). Upon insulin binding to the hepatic insulin receptor, a signaling cascade involving insulin receptor substrates (IRS), phosphoinositide 3-kinase (PI3K), and Akt is initiated. This cascade leads to the inhibition of glycogen synthase kinase 3 (GSK3) and the activation of glycogen synthase (GYS2), the rate-limiting enzyme in glycogenesis (Roach et al., 2012). This machinery is critical for the postprandial clearance of blood glucose and its storage as glycogen. Dysregulation of this system is a hallmark of insulin resistance and type 2 diabetes, where the liver fails to suppress glucose production and adequately synthesize glycogen (Adeva-Andany et al., 2016). Therapeutic strategies targeting this machinery include insulin sensitizers, glucokinase activators, and experimental GSK3 inhibitors aimed at restoring normal glucose metabolism.

Other names

Hepatic insulin signaling pathwayInsulin-mediated hepatic glycogenesisLiver glycogen synthesis systemInsulin-regulated hepatic glucose metabolism

Activation of the insulin receptor triggers a phosphorylation cascade (IRS/PI3K/Akt) that inhibits GSK3 and activates glycogen synthase (GYS2), promoting glucose storage as glycogen in the liver.