[PDF][PDF] Intracellular signals mediating the food intake-suppressive effects of hindbrain glucagon-like peptide-1 receptor activation

MR Hayes, TM Leichner, S Zhao, GS Lee… - Cell metabolism, 2011 - cell.com
MR Hayes, TM Leichner, S Zhao, GS Lee, A Chowansky, D Zimmer, BC De Jonghe
Cell metabolism, 2011cell.com
Summary Glucagon-like peptide-1 receptor (GLP-1R) activation within the nucleus tractus
solitarius (NTS) suppresses food intake and body weight (BW), but the intracellular signals
mediating these effects are unknown. Here, hindbrain (fourth icv) GLP-1R activation by
Exendin-4 (Ex-4) increased PKA and MAPK activity and decreased phosphorylation of
AMPK in NTS. PKA and MAPK signaling contribute to food intake and BW suppression by Ex-
4, as inhibitors RpcAMP and U0126 (fourth icv), respectively, attenuated Ex-4's effects …
Summary
Glucagon-like peptide-1 receptor (GLP-1R) activation within the nucleus tractus solitarius (NTS) suppresses food intake and body weight (BW), but the intracellular signals mediating these effects are unknown. Here, hindbrain (fourth i.c.v.) GLP-1R activation by Exendin-4 (Ex-4) increased PKA and MAPK activity and decreased phosphorylation of AMPK in NTS. PKA and MAPK signaling contribute to food intake and BW suppression by Ex-4, as inhibitors RpcAMP and U0126 (fourth i.c.v.), respectively, attenuated Ex-4's effects. Hindbrain GLP-1R activation inhibited feeding by reducing meal number, not meal size. This effect was attenuated with stimulation of AMPK activity by AICAR (fourth i.c.v.). The PKA, MAPK, and AMPK signaling responses by Ex-4 were present in immortalized GLP-1R-expressing neurons (GT1-7). In conclusion, hindbrain GLP-1R activation suppresses food intake and BW through coordinated PKA-mediated suppression of AMPK and activation of MAPK. Pharmacotherapies targeting these signaling pathways, which mediate intake-suppressive effects of CNS GLP-1R activation, may prove efficacious in treating obesity.
cell.com