Glucocorticoids induced high fat diet preference via activating hypothalamic AMPK signaling in chicks

Glucocorticoids (GCs) stimulate appetite, contributing to enhanced fat deposition. Our present study was conducted to determine whether GCs could evoke an appetite specifically for fat-rich diets in chicks. Chicks were subjected to a subcutaneous injection of corticosterone (CORT, 2mg/kg body weight/day) or corn oil (control), and food preference was tested. The results showed that CORT-chicks consumed more high-fat diet (HFD) compared with controls. In HFD-fed chicks, hypothalamic phosphorylated AMP-activated protein kinase α (AMPKα) and neuropeptide Y (NPY) mRNA levels were increased by CORT treatment. Activating AMPK with 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside, an AMPK activator, via intracerebroventricular injection further enhanced the CORT-induced HFD consumption and concurrently up-regulated NPY mRNA levels and phosphorylated AMPKα and acetyl-coenzyme A carboxylase levels. The dramatic increase in HFD consumption and upregulation of NPY mRNA levels and phospho-AMPKα levels induced by peripheral CORT injection was not altered by intracerebroventricular infusion of compound C (4-16μg), an AMPK inhibitor. In conclusion, CORT challenge caused a HFD preference by enhancing the AMPK pathway in the hypothalamus.