Collective and individual functions of leptin receptor modulated neurons controlling metabolism and ingestion.
Two known types of leptin-responsive neurons reside within the arcuate nucleus: the agouti gene-related peptide (AgRP)/neuropeptide Y (NPY) neuron and the proopiomelanocortin (POMC) neuron. By deleting the leptin receptor gene (Lepr) specifically in AgRP/NPY and/or POMC neurons of mice, we examined the several and combined contributions of these neurons to leptin action. Body weight and adiposity were increased by Lepr deletion from AgRP and POMC neurons individually, and simultaneous deletion in both neurons (A+P LEPR-KO mice) further increased these measures. Young (periweaning) A+P LEPR-KO mice exhibit hyperphagia and decreased energy expenditure, with increased weight gain, oxidative sparing of triglycerides, and increased fat accumulation. Interestingly, however, many of these abnormalities were attenuated in adult animals, and high doses of leptin partially suppress food intake in the A+P LEPR-KO mice. Although mildly hyperinsulinemic, the A+P LEPR-KO mice displayed normal glucose tolerance and fertility. Thus, AgRP/NPY and POMC neurons each play mandatory roles in aspects of leptin-regulated energy homeostasis, high leptin levels in adult mice mitigate the importance of leptin-responsiveness in these neurons for components of energy balance, suggesting the presence of other leptin-regulated pathways that partially compensate for the lack of leptin action on the POMC and AgRP/NPY neurons.
van de Wall
Esther
E
Departments of Medicine and Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 12461, USA.
Leshan
Rebecca
R
Xu
Allison W
AW
Balthasar
Nina
N
Coppari
Roberto
R
Liu
Shun Mei
SM
Jo
Young Hwan
YH
MacKenzie
Robert G
RG
Allison
David B
DB
Dun
Nae J
NJ
Elmquist
Joel
J
Lowell
Bradford B
BB
Barsh
Gregory S
GS
de Luca
Carl
C
Myers
Martin G
MG
Schwartz
Gary J
GJ
Chua
Streamson C
SC
D054369:Agouti-Related Protein / Q000502:physiology*; D000818:Animals; D001823:Body Composition; D004435:Eating; D004734:Energy Metabolism; D005298:Fertility; D006946:Hyperinsulinism / Q000209:etiology; D006963:Hyperphagia; D007774:Lactation; D008297:Male; D051379:Mice; D009478:Neuropeptide Y / Q000502:physiology; D011333:Pro-Opiomelanocortin / Q000502:physiology*; D054411:Receptors, Leptin / Q000502:physiology*
D054369:Agouti-Related Protein; C515199:Agrp protein, mouse; D009478:Neuropeptide Y; D054411:Receptors, Leptin; C515447:leptin receptor, mouse; D011333:Pro-Opiomelanocortin