Ghrelin-ghrelin O-acyltransferase system in the pathogenesis of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease(NAFLD) is currently considered as the most common liver disease in Western countries,and is rapidly becoming a serious threat to public health worldwide.However,the underlying mechanisms leading to the development of NAFLD are still not fully understood.The ghrelin-ghrelin O-acyltransferase(GOAT) system has recently been found to play a crucial role in both the development of steatosis and its progression to nonalcoholic steatohepatitis.Ghrelin,the natural ligand of the growth hormone secretagogue receptor,is a 28-amino acid peptide possessing a unique acylation on the serine in position 3 catalyzed by GOAT.The ghrelin-GOAT system is involved in insulin resistance,lipid metabolism dysfunction,and inflammation,all of which play important roles in the pathogenesis of NAFLD.A better understanding of ghrelin-GOAT system biology led to the identification of its potential roles in NAFLD.Molecular targets modulating ghrelin-GOAT levels and the biologic effects are being studied,which provide a new insight into the pathogenesis of NAFLD.This review probes into the possible relationship between the ghrelin-GOAT system and NAFLD,and considers the potential mechanisms by which the ghrelin-GOAT system brings about insulin resistance and other aspects concerning NAFLD.