Glucagon-like peptide-2 directly regulates hypothalamic neurons expressing neuropeptides linked to appetite control in vivo and in vitro

Endocrinology. 2012 May;153(5):2385-97. doi: 10.1210/en.2011-2089. Epub 2012 Mar 13.

Abstract

Glucagon-like peptide-2 (GLP-2), a proglucagon-derived peptide, has been postulated to affect appetite at the level of the hypothalamus. To gain better insight into this process, a degradation-resistant GLP-2 analog, human (Gly(2))GLP-2(1-33) [h(Gly(2))GLP-2] was intracerebroventricularly injected into mice to examine its action on food and water intake and also activation of hypothalamic anorexigenic α-melanocyte-stimulating hormone/proopiomelanocortin, neurotensin, and orexigenic neuropeptide Y, and ghrelin neurons. Central h(Gly(2))GLP-2 administration significantly suppressed food and water intake with acute weight loss at 2 h. Further, central h(Gly(2))GLP-2 robustly induced c-Fos activation in the hypothalamic arcuate, dorsomedial, ventromedial, paraventricular, and the lateral hypothalamic nuclei. We found differential colocalization of neuropeptides with c-Fos in specific regions of the hypothalamus. To assess whether hypothalamic neuropeptides are directly regulated by GLP-2 in vitro, we used an adult-derived clonal, immortalized hypothalamic cell line, mHypoA-2/30, that endogenously expresses functional GLP-2 receptors (GLP-2R) and two of the feeding-related neuropeptides linked to GLP-2R activation in vivo: neurotensin and ghrelin. Treatment with h(Gly(2))GLP-2 stimulated c-Fos expression and phosphorylation of cAMP response element-binding protein/activating transcription factor-1. In addition, treatment with h(Gly(2))GLP-2 significantly increased neurotensin and ghrelin mRNA transcript levels by 50 and 95%, respectively, at 24 h after treatment in protein kinase A-dependent manner. Taken together, these findings implicate the protein kinase A pathway as the means by which GLP-2 can up-regulate hypothalamic neuropeptide mRNA levels and provide evidence for a link between central GLP-2R activation and specific hypothalamic neuropeptides involved in appetite regulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dose-Response Relationship, Drug
  • Drinking / drug effects
  • Drinking / physiology
  • Eating / drug effects*
  • Eating / physiology
  • Ghrelin / genetics
  • Ghrelin / metabolism
  • Glucagon-Like Peptide 2 / pharmacology*
  • Hypothalamus / drug effects*
  • Hypothalamus / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Microinjections
  • Neurons / drug effects*
  • Neurons / metabolism
  • Neuropeptide Y / genetics
  • Neuropeptide Y / metabolism
  • Neurotensin / genetics
  • Neurotensin / metabolism
  • Pro-Opiomelanocortin / genetics
  • Pro-Opiomelanocortin / metabolism
  • Proto-Oncogene Proteins c-fos / metabolism

Substances

  • Ghrelin
  • Glucagon-Like Peptide 2
  • Neuropeptide Y
  • Proto-Oncogene Proteins c-fos
  • Neurotensin
  • Pro-Opiomelanocortin