mTORC1 signaling in Agrp neurons mediates circadian expression of Agrp and NPY but is dispensable for regulation of feeding behavior

Biochem Biophys Res Commun. 2015 Aug 21;464(2):480-6. doi: 10.1016/j.bbrc.2015.06.161. Epub 2015 Jul 6.

Abstract

Orexigenic agouti-related protein/neuropeptide Y (Agrp/NPY) neurons and an orexigenic pro-opiomelanocortin (POMC) neurons of the hypothalamus regulate feeding behavior and energy homeostasis. An understanding of the molecular signaling pathways that regulate Agrp/NPY and POMC function could lead to novel treatments for metabolic disorders. Target of Rapamycin Complex 1 (TORC1) is a nutrient-activated protein kinase and central controller of growth and metabolism. We therefore investigated the role of mammalian TORC1 (mTORC1) in Agrp neurons. We generated and characterized Agrp neuron-specific raptor knockout (Agrp-raptor KO) mice. Agrp-raptor KO mice displayed reduced, non-circadian expression of Agrp and NPY but normal feeding behavior and energy homeostasis on both normal and high fat diet. Thus, mTORC1 in Agrp neurons controls circadian expression of orexigenic neuropeptides but is dispensable for the regulation of feeding behavior and energy metabolism.

Keywords: Agrp; Hypothalamus; Metabolism; NPY; Raptor; mTORC1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Agouti-Related Protein / genetics
  • Agouti-Related Protein / metabolism*
  • Animals
  • Circadian Rhythm*
  • Feeding Behavior*
  • Mechanistic Target of Rapamycin Complex 1
  • Mice
  • Mice, Knockout
  • Multiprotein Complexes / metabolism*
  • Neurons / metabolism*
  • Neuropeptide Y / metabolism*
  • Oxidative Stress
  • Regulatory-Associated Protein of mTOR
  • Signal Transduction
  • TOR Serine-Threonine Kinases / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • Agouti-Related Protein
  • Agrp protein, mouse
  • Multiprotein Complexes
  • Neuropeptide Y
  • Regulatory-Associated Protein of mTOR
  • Rptor protein, mouse
  • Mechanistic Target of Rapamycin Complex 1
  • TOR Serine-Threonine Kinases