Nicotine induces negative energy balance through hypothalamic AMP-activated protein kinase.
Smokers around the world commonly report increased body weight after smoking cessation as a major factor that interferes with their attempts to quit. Numerous controlled studies in both humans and rodents have reported that nicotine exerts a marked anorectic action. The effects of nicotine on energy homeostasis have been mostly pinpointed in the central nervous system, but the molecular mechanisms controlling its action are still not fully understood. The aim of this study was to investigate the effect of nicotine on hypothalamic AMP-activated protein kinase (AMPK) and its effect on energy balance. Here we demonstrate that nicotine-induced weight loss is associated with inactivation of hypothalamic AMPK, decreased orexigenic signaling in the hypothalamus, increased energy expenditure as a result of increased locomotor activity, increased thermogenesis in brown adipose tissue (BAT), and alterations in fuel substrate utilization. Conversely, nicotine withdrawal or genetic activation of hypothalamic AMPK in the ventromedial nucleus of the hypothalamus reversed nicotine-induced negative energy balance. Overall these data demonstrate that the effects of nicotine on energy balance involve specific modulation of the hypothalamic AMPK-BAT axis. These targets may be relevant for the development of new therapies for human obesity.
Department of Physiology, School of Medicine-CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, A Coruña, Spain.
Pablo B
PB
Martínez de Morentin
Andrew J
AJ
Whittle
Johan
J
Fernø
Rubén
R
Nogueiras
Carlos
C
Diéguez
Antonio
A
Vidal-Puig
Miguel
M
López
D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001066:Appetite / Q000187:drug effects; D004435:Eating / Q000187:drug effects*; D004734:Energy Metabolism / Q000187:drug effects*; D005786:Gene Expression Regulation / Q000187:drug effects; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009478:Neuropeptide Y / Q000378:metabolism; D009538:Nicotine / Q000494:pharmacology*; D011333:Pro-Opiomelanocortin / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011978:Receptors, Nicotinic / Q000235:genetics / Q000378:metabolism; D013693:Temazepam; D022722:Thermogenesis / Q000187:drug effects
D009478:Neuropeptide Y; D011978:Receptors, Nicotinic; C403530:nicotinic receptor alpha3beta4; D011333:Pro-Opiomelanocortin; D009538:Nicotine; D013693:Temazepam; C543928:Prkaa2 protein, rat; D055372:AMP-Activated Protein Kinases; C568305:Prkaa1 protein, rat