Nicotine' actions on energy balance: friend or foe?

Abstract

Teixit adipós; Receptors nicotínics; Obesitat

Tejido adiposo; Receptores nicotínicos; Obesidad

Adipose tissue; Nicotinic receptors; Obesity

Obesity has reached pandemic proportions and is associated with severe comorbidities, such as type 2 diabetes mellitus, hepatic and cardiovascular diseases, and certain cancer types. However, the therapeutic options to treat obesity are limited. Extensive epidemiological studies have shown a strong relationship between smoking and body weight, with non-smokers weighing more than smokers at any age. Increased body weight after smoking cessation is a major factor that interferes with their attempts to quit smoking. Numerous controlled studies in both humans and rodents have reported that nicotine, the main bioactive component of tobacco, exerts a marked anorectic action. Furthermore, nicotine is also known to modulate energy expenditure, by regulating the thermogenic activity of brown adipose tissue (BAT) and the browning of white adipose tissue (WAT), as well as glucose homeostasis. Many of these actions occur at central level, by controlling the activity of hypothalamic neuropeptide systems such as proopiomelanocortin (POMC), or energy sensors such as AMP-activated protein kinase (AMPK). However, direct impact of nicotine on metabolic tissues, such as BAT, WAT, liver and pancreas has also been described. Here, we review the actions of nicotine on energy balance. The relevance of this interaction is interesting, because considering the restricted efficiency of obesity treatments, a possible complementary approach may focus on compounds with known pharmacokinetic profile and pharmacological actions, such as nicotine or nicotinic acetylcholine receptors signaling.

Xunta de Galicia (RN: 2016-PG057; ML: 2016-PG068); Ministerio de Economía y Competitividad (MINECO) co-funded by the FEDER Program of EU (RN: RTI2018-099413-B-I00; CD: BFU2017- 87721-P; ML: RTI2018-101840-B-I00; JMF-R and ML: BFU2017- 90578-REDT/Adipoplast); Instituto de Salud Carlos III (JMF-R: PI15–01934); Atresmedia Corporación (RN and ML); Fundación BBVA (RN); “la Caixa” Foundation (ID 100010434), under the agreement LCF/PR/HR19/52160022 (ML); European Foundation for the Study of Diabetes (RN); ERC Synergy Grant-2019-WATCH- 810331 (RN); US Na- tional Institutes of Health (KR: HL084207); the US Department of Vet- erans Affairs (KR: I01BX004249); The University of Iowa Fraternal Order of Eagles Diabetes Research Center (KR). PS-C is recipient of a fel- lowship from Xunta de Galicia (ED481B 2018/050). The CiMUS is sup- ported by the Xunta de Galicia (2016-2019, ED431G/05). CIBER de Fisiopatología de la Obesidad y Nutrición is an initiative of ISCIII.