scholarly journals The deletion of glucagon-like peptide-1 receptors expressing neurons in the dorsomedial hypothalamic nucleus disrupts the diurnal feeding pattern and induces hyperphagia and obesity

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Yuko Maejima ◽  
Shoko Yokota ◽  
Masaru Shimizu ◽  
Shoichiro Horita ◽  
Daisuke Kobayashi ◽  
...  

Abstract Background Feeding rhythm disruption contributes to the development of obesity. The receptors of glucagon-like peptide-1 (GLP-1) are distributed in the wide regions of the brain. Among these regions, GLP-1 receptors (GLP-1R) are expressed in the dorsomedial hypothalamic nucleus (DMH) which are known to be associated with thermogenesis and circadian rhythm development. However, the physiological roles of GLP-1R expressing neurons in the DMH remain elusive. Methods To examine the physiological role of GLP-1R expressing neurons in the DMH, saporin-conjugated exenatide4 was injected into rat brain DMH to delete GLP-1R-positive neurons. Subsequently, locomotor activity, diurnal feeding pattern, amount of food intake and body weight were measured. Results This deletion of GLP-1R-positive neurons in the DMH induced hyperphagia, the disruption of diurnal feeding pattern, and obesity. The deletion of GLP-1R expressing neurons also reduced glutamic acid decarboxylase 67 and cholecystokinin A receptor mRNA levels in the DMH. Also, it reduced the c-fos expression after refeeding in the suprachiasmatic nucleus (SCN). Thirty percent of DMH neurons projecting to the SCN expressed GLP-1R. Functionally, refeeding after fasting induced c-fos expression in the SCN projecting neurons in the DMH. As for the projection to the DMH, neurons in the nucleus tractus solitarius (NTS) were found to be projecting to the DMH, with 33% of those neurons being GLP-1-positive. Refeeding induced c-fos expression in the DMH projecting neurons in the NTS. Conclusion These findings suggest that GLP-1R expressing neurons in the DMH may mediate feeding termination. In addition, this meal signal may be transmitted to SCN neurons and change the neural activities.

2008 ◽  
Vol 1204 ◽  
pp. 77-86 ◽  
Author(s):  
Peter Kobelt ◽  
Anna-Sophia Wisser ◽  
Andreas Stengel ◽  
Miriam Goebel ◽  
Tobias Inhoff ◽  
...  

Endocrinology ◽  
2013 ◽  
Vol 154 (12) ◽  
pp. 4503-4511 ◽  
Author(s):  
Niels-Erik Viby ◽  
Marie S. Isidor ◽  
Katrine B. Buggeskov ◽  
Steen S. Poulsen ◽  
Jacob B. Hansen ◽  
...  

The incretin hormone glucagon-like peptide-1 (GLP-1) is an important insulin secretagogue and GLP-1 analogs are used for the treatment of type 2 diabetes. GLP-1 displays antiinflammatory and surfactant-releasing effects. Thus, we hypothesize that treatment with GLP-1 analogs will improve pulmonary function in a mouse model of obstructive lung disease. Female mice were sensitized with injected ovalbumin and treated with GLP-1 receptor (GLP-1R) agonists. Exacerbation was induced with inhalations of ovalbumin and lipopolysaccharide. Lung function was evaluated with a measurement of enhanced pause in a whole-body plethysmograph. mRNA levels of GLP-1R, surfactants (SFTPs), and a number of inflammatory markers were measured. GLP-1R was highly expressed in lung tissue. Mice treated with GLP-1R agonists had a noticeably better clinical appearance than the control group. Enhanced pause increased dramatically at day 17 in all control mice, but the increase was significantly less in the groups of GLP-1R agonist-treated mice (P < .001). Survival proportions were significantly increased in GLP-1R agonist-treated mice (P < .01). SFTPB and SFTPA were down-regulated and the expression of inflammatory cytokines were increased in mice with obstructive lung disease, but levels were largely unaffected by GLP-1R agonist treatment. These results show that GLP-1R agonists have potential therapeutic potential in the treatment of obstructive pulmonary diseases, such as chronic obstructive pulmonary disease, by decreasing the severity of acute exacerbations. The mechanism of action does not seem to be the modulation of inflammation and SFTP expression.


2012 ◽  
Vol 48 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Hongjie Zhang ◽  
Jing Li ◽  
Xiangying Liang ◽  
Yun Luo ◽  
Ke Zen ◽  
...  

It is known that endogenous levels of the incretin hormone glucagon-like peptide 1 (GLP1) can be enhanced by various secretagogues, but the mechanism underlying GLP1 secretion is still not fully understood. We assessed the possible effect of uncoupling protein 2 (UCP2) on GLP1 secretion in mouse intestinal tract and NCI-H716 cells, a well-characterized human enteroendocrine L cell model. Localization of UCP2 and GLP1 in the gastrointestinal tract was assessed by immunofluorescence staining. Ucp2 mRNA levels in gut were analyzed by quantitative RT-PCR. Human NCI-H716 cells were transiently transfected with siRNAs targeting UCP2. The plasma and ileum tissue levels of GLP1 (7–36) amide were measured using an ELISA kit. UCP2 was primarily expressed in the mucosal layer and colocalized with GLP1 in gastrointestinal mucosa. L cells secreting GLP1 also expressed UCP2. After glucose administration, UCP2-deficient mice showed increased glucose-induced GLP1 secretion compared with wild-type littermates. GLP1 secretion increased after NCI-H716 cells were transfected with siRNAs targeting UCP2. UCP2 was markedly upregulated in ileum tissue from ob/ob mice, and GLP1 secretion decreased compared with normal mice. Furthermore, GLP1 secretion increased after administration of genipin by oral gavage. Taken together, these results reveal an inhibitory role of UCP2 in glucose-induced GLP1 secretion.


2009 ◽  
Vol 296 (1) ◽  
pp. R51-R56 ◽  
Author(s):  
Lori Asarian

To investigate the role of serotonin 2C receptors (2CR), which are expressed only in the central nervous system, in the satiating actions of the gut peptides CCK and glucagon-like peptide 1 (GLP-1), we examined 1) the effect of null mutations of serotonin 2CR (2CR KO) on the eating-inhibitory potencies of dark-onset intraperitoneal injections of 0.9, 1.7, or 3.5 nmol/kg (1, 2, or 4 μg/kg) CCK and 100, 200, and 400 nmol/kg (33, 66, or 132 μg/kg) GLP-1, and 2) the effects of intraperitoneal injections of 1.7 nmol//kg CCK and 100 nmol/kg GLP-1 on neuronal activation in the brain, as measured by c-Fos expression. All CCK and GLP-1 doses decreased 30-min food intake in wild-type (WT) mice, but none of them did in 2CR KO mice. CCK increased the number of cells expressing c-Fos in the nucleus tractus solitarii (NTS) of WT, but not 2CR KO mice. CCK induced similar degrees of c-Fos expression in the paraventricular (PVN) and arcuate (Arc) nuclei of the hypothalamus of both genotypes. GLP-1, on the other hand, increased c-Fos expression similarly in the NTS of both genotypes and increased c-Fos expression more in the PVN and Arc of 2CR KO mice, but not WT mice. These results indicate that serotonin signaling via serotonin 2CR is necessary for the full satiating effects of CCK and GLP-1. In addition, they suggest that the satiating effects of the two peptides are mediated by different neural mechanisms.


2013 ◽  
Vol 221 (1) ◽  
pp. T1-T16 ◽  
Author(s):  
L van Bloemendaal ◽  
J S ten Kulve ◽  
S E la Fleur ◽  
R G Ijzerman ◽  
M Diamant

The delivery of nutrients to the gastrointestinal tract after food ingestion activates the secretion of several gut-derived mediators, including the incretin hormone glucagon-like peptide 1 (GLP-1). GLP-1 receptor agonists (GLP-1RA), such as exenatide and liraglutide, are currently employed successfully in the treatment of patients with type 2 diabetes mellitus. GLP-1RA improve glycaemic control and stimulate satiety, leading to reductions in food intake and body weight. Besides gastric distension and peripheral vagal nerve activation, GLP-1RA induce satiety by influencing brain regions involved in the regulation of feeding, and several routes of action have been proposed. This review summarises the evidence for a physiological role of GLP-1 in the central regulation of feeding behaviour and the different routes of action involved. Also, we provide an overview of presently available data on pharmacological stimulation of GLP-1 pathways leading to alterations in CNS activity, reductions in food intake and weight loss.


Author(s):  
Daniel I. Brierley ◽  
Marie K. Holt ◽  
Arashdeep Singh ◽  
Alan de Araujo ◽  
Macarena Vergara ◽  
...  

AbstractThe anorexigenic peptide glucagon-like peptide-1 (GLP-1) is secreted from gut enteroendocrine cells and brain preproglucagon (PPG) neurons, which respectively define the peripheral and central GLP-1 systems. As peripheral satiation signals are integrated in the nucleus tractus solitarius (NTS), PPGNTS neurons are assumed to link the peripheral and central GLP-1 systems, forming a unified GLP-1 gut-brain satiation circuit. This hypothesis, however, remains unsubstantiated. We report that PPGNTS neurons encode satiation in mice, consistent with vagal gastrointestinal distension signalling. However, PPGNTS neurons predominantly receive vagal input from oxytocin receptor-expressing vagal neurons, rather than those expressing GLP-1 receptors. Furthermore, PPGNTS neurons are not necessary for eating suppression induced by the GLP-1 receptor agonists liraglutide or semaglutide, and semaglutide and PPGNTS neuron activation additively suppress eating. Central and peripheral GLP-1 systems thus suppress eating via independent gut-brain circuits, hence PPGNTS neurons represent a rational pharmacological target for anti-obesity combination therapy with GLP-1 receptor agonists.Abstract FigureGraphical Abstract:


2005 ◽  
Vol 185 (3) ◽  
pp. 457-465 ◽  
Author(s):  
Patrice D Cani ◽  
Catherine A Daubioul ◽  
Brigitte Reusens ◽  
Claude Remacle ◽  
Grégory Catillon ◽  
...  

We have evaluated the influence of oligofructose (OFS), a fermentable dietary fibre, on glucose homeostasis, insulin production and intestinal glucagon-like peptide-1 (GLP-1) in streptozotocin-treated diabetic rats. Male Wistar rats received either i.v. streptozotocin (STZ; 40 mg/kg) or vehicle (CT); one week later, they were fed for 6 weeks with either the standard diet (STZ-CT), or with a diet containing 10% oligofructose (STZ-OFS); both diets were available ad libitum. In a second set of experiments (duration 4 weeks), a supplemental group of food-restricted rats (STZ-Res) receiving a similar intake as CT rats, was added. OFS improved glucose tolerance and reduced food intake as compared with STZ-CT rats in both the post-prandial state and after an oral glucose tolerance test. After 6 weeks, portal and pancreatic insulin concentrations were doubled in STZ-OFS rats. Food restriction improved these parameters when compared with STZ-CT rats, but to a lesser extent than in the STZ-OFS group. We have shown that OFS treatment increased portal and colonic GLP-1(7–36) amide levels and doubled colonic proglucagon and prohormone convertase 1 mRNA levels; both OFS and food restriction lowered ileal GLP-1(7–36) amide levels as compared with levels in STZ-CT rats. We propose that OFS, through its fermentation in the colon, promotes the expression and secretion of colonic peptides, namely GLP-1(7–36) amide, with beneficial consequences on glycaemia, insulin secretion and hyperphagia in diabetic rats.


Sign in / Sign up

Export Citation Format

Share Document