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Krieger JP, Santos da Conceição EP, Sanchez-Watts G, Arnold M, Pettersen KG, Mohammed M, Modica S, Lossel P, Morrison SF, Madden CJ, Watts AG, Langhans W, Lee SJ. Glucagon-like peptide-1 regulates brown adipose tissue thermogenesis via the gut-brain axis in rats. Am J Physiol Regul Integr Comp Physiol 2018; 315:R708-R720. [PMID: 29847161 DOI: 10.1152/ajpregu.00068.2018] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Endogenous intestinal glucagon-like peptide-1 (GLP-1) controls satiation and glucose metabolism via vagal afferent neurons (VANs). Recently, VANs have received increasing attention for their role in brown adipose tissue (BAT) thermogenesis. It is, however, unclear whether VAN GLP-1 receptor (GLP-1R) signaling affects BAT thermogenesis and energy expenditure (EE) and whether this VAN mechanism contributes to energy balance. First, we tested the effect of the GLP-1R agonist exendin-4 (Ex4, 0.3 μg/kg ip) on EE and BAT thermogenesis and whether these effects require VAN GLP-1R signaling using a rat model with a selective Glp1r knockdown (kd) in VANs. Second, we examined the role of VAN GLP-1R in energy balance during chronic high-fat diet (HFD) feeding in VAN Glp1r kd rats. Finally, we used viral transsynaptic tracers to identify the possible neuronal substrates of such a gut-BAT interaction. VAN Glp1r kd attenuated the acute suppressive effects of Ex4 on EE and BAT thermogenesis. Consistent with this finding, the VAN Glp1r kd increased EE and BAT activity, diminished body weight gain, and improved insulin sensitivity compared with HFD-fed controls. Anterograde transsynaptic viral tracing of VANs infected major hypothalamic and hindbrain areas involved in BAT sympathetic regulation. Moreover, retrograde tracing from BAT combined with laser capture microdissection revealed that a population of VANs expressing Glp1r is synaptically connected to the BAT. Our findings reveal a novel role of VAN GLP-1R signaling in the regulation of EE and BAT thermogenesis and imply that through this gut-brain-BAT connection, intestinal GLP-1 plays a role in HFD-induced metabolic syndrome.
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Affiliation(s)
- Jean-Philippe Krieger
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | | | - Graciela Sanchez-Watts
- Department of Biological Sciences, University of Southern California , Los Angeles, California
| | - Myrtha Arnold
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Klaus G Pettersen
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Mazher Mohammed
- Department of Neurological Surgery, Oregon Health and Science University , Portland, Oregon
| | - Salvatore Modica
- Translational Nutrition Biology Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Pius Lossel
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Shaun F Morrison
- Department of Neurological Surgery, Oregon Health and Science University , Portland, Oregon
| | - Christopher J Madden
- Department of Neurological Surgery, Oregon Health and Science University , Portland, Oregon
| | - Alan G Watts
- Department of Biological Sciences, University of Southern California , Los Angeles, California
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Shin J Lee
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
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Krieger JP, Arnold M, Pettersen KG, Lossel P, Langhans W, Lee SJ. Knockdown of GLP-1 Receptors in Vagal Afferents Affects Normal Food Intake and Glycemia. Diabetes 2016; 65:34-43. [PMID: 26470787 DOI: 10.2337/db15-0973] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/16/2015] [Indexed: 11/13/2022]
Abstract
Nutrient stimulation of enteroendocrine L cells induces the release of the incretin and satiating peptide glucagon-like peptide 1 (GLP-1). The vagus nerve innervates visceral organs and may contribute to the mediation of gut-derived GLP-1's effects on food intake, energy homeostasis, and glycemic control. To test the hypothesis that vagal afferent neuron (VAN) GLP-1 receptors (GLP-1Rs) are necessary for these effects of endogenous GLP-1, we established a novel bilateral nodose ganglia injection technique to deliver a lentiviral vector and to knock down VAN GLP-1Rs in male Sprague Dawley rats. We found that a full expression of VAN GLP-1Rs is not necessary for the maintenance of long-term energy balance in normal eating conditions. VAN GLP-1R knockdown (kd) did, however, increase meal size and accelerated gastric emptying. Moreover, postmeal glycemia was elevated and insulin release was blunted in GLP-1R kd rats, suggesting that VAN GLP-1Rs are physiological contributors to the neuroincretin effect after a meal. Collectively, our results highlight a crucial role for the VANs in mediating the effects of endogenous GLP-1 on food intake and glycemia and may promote the further development of GLP-1-based therapies.
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Affiliation(s)
- Jean-Philippe Krieger
- Physiology and Behavior Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
| | - Myrtha Arnold
- Physiology and Behavior Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
| | - Klaus G Pettersen
- Physiology and Behavior Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
| | - Pius Lossel
- Physiology and Behavior Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
| | - Shin J Lee
- Physiology and Behavior Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
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