The role of hepatokines in NAFLD-related extrahepatic diseases: culprit or accomplice?

Fibroblast growth factor 21 (FGF21), a hepatokine that is mainly secreted by the liver, has beneficial effects for improving metabolic processes. 2 It has been well recognised that FGF21 plays a pivotal role in the pathogenesis and therapeutic mechanisms of NAFLD. 3 Abnormality in FGF21 would prompt the development of NAFLD. Selenoprotein P, a 42kDa glycoprotein, is produced in the liver. 8 It has been reported that selenoprotein P impairs insulin signalling and glucose metabolism in the liver, whereas decreasing selenoprotein P could elicit beneficial effects on insulin resistance and glucose tolerance. 8 Increased selenoprotein P levels are highly associated with NAFLD. Recently, Ishikura et al 9 demonstrated that selenoprotein P in the physiological concentration range has deleterious effects by inhibiting vascular endothelial growth factor, tubule formation and migration in endothelial cells.