Tachykinin-1 in the central nervous system regulates adiposity in rodents.
Ghrelin is a circulating hormone that targets the central nervous system to regulate feeding and adiposity. The best-characterized neural system that mediates the effects of ghrelin on energy balance involves the activation of neuropeptide Y/agouti-related peptide neurons, expressed exclusively in the arcuate nucleus of the hypothalamus. However, ghrelin receptors are expressed in other neuronal populations involved in the control of energy balance. We combined laser capture microdissection of several nuclei of the central nervous system expressing the ghrelin receptor (GH secretagoge receptor) with microarray gene expression analysis to identify additional neuronal systems involved in the control of central nervous system-ghrelin action. We identified tachykinin-1 (Tac1) as a gene negatively regulated by ghrelin in the hypothalamus. Furthermore, we identified neuropeptide k as the TAC1-derived peptide with more prominent activity, inducing negative energy balance when delivered directly into the brain. Conversely, loss of Tac1 expression enhances the effectiveness of ghrelin promoting fat mass gain both in male and in female mice and increases the susceptibility to diet-induced obesity in ovariectomized mice. Taken together, our data demonstrate a role TAC1 in the control energy balance by regulating the levels of adiposity in response to ghrelin administration and to changes in the status of the gonadal function.
Metabolic Diseases Institute (C.T., D.K., J.H., S.A., K.H., H.K., D.P.-T.), Department of Medicine, University of Cincinnati, Cincinnati, Ohio 45237; Department of Pharmacology and Toxicology, Zydus Research Centre, Cadila Healthcare Ltd. (C.T.), Ahmedabab 382210, India; and Medical Research Council (MRC) Metabolic Diseases Unit (X.S., Y.-C.L.T., G.S.H.Y.), University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom.
Chitrang
C
Trivedi
Xiaoye
X
Shan
Yi-Chun Loraine
YC
Tung
Dhiraj
D
Kabra
Jenna
J
Holland
Sarah
S
Amburgy
Kristy
K
Heppner
Henriette
H
Kirchner
Giles S H
GS
Yeo
Diego
D
Perez-Tilve
D050154:Adiposity; D000818:Animals; D001921:Brain / Q000378:metabolism*; D059305:Diet, High-Fat; D004734:Energy Metabolism / Q000187:drug effects / Q000235:genetics*; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology*; D005260:Female; D020869:Gene Expression Profiling; D054439:Ghrelin / Q000378:metabolism*; D008297:Male; D051379:Mice; D009765:Obesity / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D054440:Receptors, Ghrelin / Q000378:metabolism*; D015320:Tachykinins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology
D054439:Ghrelin; D012333:RNA, Messenger; D054440:Receptors, Ghrelin; D015320:Tachykinins; C045206:neuropeptide K