Exendin-4 reduces food intake via the PI3K/AKT signaling pathway in the hypothalamus.
Yan YangPique P ChoiWanli W SmithWeijie XuDelin MaZachary A CordnerNu-Chu LiangTimothy H MoranPublished in: Scientific reports (2017)
Exendin-4 (EX-4), a glucagon-like peptide-1 (GLP-1) receptor agonist, has been shown to reduce food intake and to increase proopiomelanocortin (POMC) gene expression in the hypothalamus. In this study, we examined the potential neural mechanisms by which these effects occur. Male Sprague Dawley rats were implanted with a cannula in the third ventricle of the brain through which an inhibitor of phosphatidylinositol-3 kinase (PI3K) (wortmannin) was administered, and EX-4 or vehicle was administered via intraperitoneal (IP) injection. The activity of PI3K/protein kinase B (AKT) and insulin receptor substrate-1 (IRS-1) in the hypothalamic arcuate was determined. We found that EX-4 treatment significantly decreased food intake and body weight. However, there were almost no changes in food intake and body weight when wortmannin injection (into the third ventricle) occurred prior to EX-4 IP injection. EX-4 not only increased the activity of PI3K/AKT, but it also increased IRS-1 activity. These results show that EX-4 likely suppresses food intake due to its ability to enhance insulin signaling.
Keyphrases
- body weight
- signaling pathway
- pi k akt
- protein kinase
- gene expression
- type diabetes
- cell proliferation
- induced apoptosis
- pulmonary artery
- ultrasound guided
- cell cycle arrest
- epithelial mesenchymal transition
- pulmonary hypertension
- dna methylation
- mitral valve
- oxidative stress
- glycemic control
- metabolic syndrome
- heart failure
- resting state
- tyrosine kinase
- left ventricular
- combination therapy
- congenital heart disease
- atrial fibrillation
- brain injury
- functional connectivity
- cerebral ischemia
- blood brain barrier
- smoking cessation
- binding protein