Targeted disruption of GPR7, the endogenous receptor for neuropeptides B and W, leads to metabolic defects and adult-onset obesity Academic Article uri icon

Overview

MeSH Major

  • Energy Metabolism
  • Obesity
  • Receptors, Neuropeptide

abstract

  • Gold-thioglucose (GTG) induces lesions in the ventromedial nucleus of the hypothalamus, resulting in hyperphagia and obesity. To identify genes involved in the hypothalamic regulation of energy homeostasis, we used a screen for genes that are dysregulated in GTG-induced obese mice. We found that GPR7, the endogenous G protein-coupled receptor for the recently identified ligands neuropeptide B and neuropeptide W, was down-regulated in hypothalamus after GTG treatment. Here we show that male GPR7-/- mice develop an adult-onset obese phenotype that progressively worsens with age and was greatly exacerbated when animals are fed a high-fat diet. GPR7-/- male mice were hyperphagic and had decreased energy expenditure and locomotor activity. Plasma levels of glucose, leptin, and insulin were also elevated in these mice. GPR7-/- male mice had decreased hypothalamic neuropeptide Y RNA levels and increased proopiomelanocortin RNA levels, a set of effects opposite to those evident in ob/ob mice. Furthermore, ob/ob GPR7-/- and Ay/a GPR7-/- double mutant male mice had an increased body weight compared with normal ob/ob or Ay/a male mice, suggesting that the obesity of GPR7-/- mice is independent of leptin and melanocortin signaling. Female mice did not show any significant weight increase or associated metabolic defects. These data suggest a potential role for GPR7 and its endogenous ligands, neuropeptide B and neuropeptide W, in regulating energy homeostasis independent of leptin and melanocortin signaling in a sexually dimorphic manner.

publication date

  • September 2, 2003

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC193597

Digital Object Identifier (DOI)

  • 10.1073/pnas.1334189100

PubMed ID

  • 12925742

Additional Document Info

start page

  • 10540

end page

  • 5

volume

  • 100

number

  • 18