GFRAL-expressing neurons suppress food intake via aversive pathways

The TGFβ cytokine family member, GDF-15, reduces food intake and body weight and represents a potential treatment for obesity. Because the brainstem-restricted expression pattern of its receptor, GDNF Family Receptor α–like (GFRAL), presents an exciting opportunity to understand mechanisms of action for area postrema neurons in food intake; we generated GfralCre and conditional GfralCreERT mice to visualize and manipulate GFRAL neurons. We found infection or pathophysiologic states (rather than meal ingestion) stimulate GFRAL neurons. TRAP-Seq analysis of GFRAL neurons revealed their expression of a wide range of neurotransmitters and neuropeptides. Artificially activating GfralCre-expressing neurons inhibited feeding, decreased gastric emptying, and promoted a conditioned taste aversion (CTA). GFRAL neurons most strongly innervate the parabrachial nucleus (PBN), where they target CGRP-expressing (CGRPPBN) neurons. Silencing CGRPPBN neurons abrogated the aversive and anorexic effects of GDF-15. These findings suggest that GFRAL neurons link non–meal-associated pathophysiologic signals to suppress nutrient uptake and absorption.

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Gfral-expressing Neurons Suppress Food Intake via Aversive Pathways

10.1101/2020.05.11.088773 ◽

2020 ◽

Author(s):

Paul V. Sabatini ◽

Henriette Frikke-Schmidt ◽

Joe Arthurs ◽

Desiree Gordian ◽

Anita Patel ◽

...

Keyword(s):

Gastric Emptying ◽

Food Intake ◽

Taste Aversion ◽

Conditioned Taste Aversion ◽

Mechanisms Of Action ◽

Parabrachial Nucleus ◽

Gastric Physiology ◽

Anorexigenic Peptide ◽

Artificial Activation ◽

Meal Ingestion

AbstractTo determine the function and mechanisms of action for hindbrain neurons that express GFRAL, the receptor for the anorexigenic peptide, GDF-15, we generated Gfralcre and conditional GfralCreERT mice. While signals of infection or pathophysiologic states (rather than meal ingestion) stimulate GFRAL neurons, the artificial activation of GfralCre- expressing neurons inhibited feeding, decreased gastric emptying, and promoted a conditioned taste aversion (CTA). Additionally, activation of the smaller population of GFRAL neurons captured by the GfralCreERT allele decreased gastric emptying and produced a CTA without suppressing food intake, suggesting that GFRAL neurons primarily modulate gastric physiology and stimulate aversive responses. GFRAL neurons most strongly innervated the parabrachial nucleus (PBN), where they targeted CGRP-expressing (CGRPPBN) neurons. Silencing CGRPPBN neurons abrogated the aversive and anorexic effects of GDF-15. These findings suggest that GFRAL neurons link non-meal-associated, pathophysiologic signals to the aversive suppression of nutrient uptake and absorption.

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SUN-269 Activation of GFRAL Neurons Decreases Food Intake via Aversive Pathways

Journal of the Endocrine Society ◽

10.1210/jendso/bvaa046.1272 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

Author(s):

Paul Sabatini ◽

Henriette Frikke-Schmidt ◽

Alan Rupp ◽

Desiree Gordian ◽

Martin Myers Jr ◽

...

Keyword(s):

Gastric Emptying ◽

Food Intake ◽

Conditioned Taste Aversion ◽

Area Postrema ◽

Mechanisms Of Action ◽

Parabrachial Nucleus ◽

Peptide Mimetics ◽

Solitary Tract ◽

Promising Candidate ◽

Anorexigenic Peptide

Abstract Growth and differentiation factor 15 (GDF15), an anorexigenic peptide that represents a promising candidate for anti-obesity treatment, acts via GDNF Family Receptor Alpha Like (GFRAL), which is expressed almost exclusively on a subset of neurons in the area postrema (AP). To determine the function and mechanisms of action for GFRAL neurons, we generated Gfralcre and conditional GfralCreERT mice. Although their chemogenetic (DREADD-mediated) activation promoted FOS in a variety of brainstem, hypothalamic, and limbic nuclei, GFRAL neurons projected only to the nucleus of the solitary tract (NTS) and the parabrachial nucleus (PBN), where they innervated and activated aversive/anorexigenic GCRP-expressing cells. Tetanus-toxin-mediated silencing of PBN CGRP neurons abrogated the aversive and anorexic effects of GDF15. Furthermore, while non-gastrointestinal (GI) stimuli (e.g., GDF15 and LPS, but not feeding or gut peptide mimetics) activated GFRAL neurons, chemogenetically activating these cells decreased gastric emptying, suppressed feeding, and promoted a conditioned taste aversion. These findings suggest that GFRAL neurons link non-GI anorexigenic signals to the control of gut physiology and to the aversive suppression of food intake. Additionally, because the chemogenetic activation of GFRAL neurons suppressed food intake more strongly than GDF15 in lean mice, additional modes of activating GFRAL neurons may augment the anorectic potential of GDF15.

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Ghrelin in the lateral parabrachial nucleus influences the excitability of glucosensing neurons, increases food intake and body weight

Endocrine Connections ◽

10.1530/ec-20-0285 ◽

2020 ◽

Vol 9 (12) ◽

pp. 1168-1177

Author(s):

Caishun Zhang ◽

Junhua Yuan ◽

Qian Lin ◽

Manwen Li ◽

Liuxin Wang ◽

...

Keyword(s):

Body Weight ◽

Weight Gain ◽

Food Intake ◽

Firing Rate ◽

Body Weight Gain ◽

Parabrachial Nucleus ◽

Growth Hormone Secretagogue Receptor ◽

Growth Hormone Secretagogue ◽

Lateral Parabrachial Nucleus

Ghrelin plays a pivotal role in the regulation of food intake, body weight and energy metabolism. However, these effects of ghrelin in the lateral parabrachial nucleus (LPBN) are unexplored. C57BL/6J mice and GHSR−/− mice were implanted with cannula above the right LPBN and ghrelin was microinjected via the cannula to investigate effect of ghrelin in the LPBN. In vivo electrophysiological technique was used to record LPBN glucose-sensitive neurons to explore potential udnderlying mechanisms. Microinjection of ghrelin in LPBN significantly increased food intake in the first 3 h, while such effect was blocked by [D-Lys3]-GHRP-6 and abolished in GHSR−/− mice. LPBN ghrelin microinjection also significantly increased the firing rate of glucose-excited (GE) neurons and decreased the firing rate of glucose-inhibited (GI) neurons. Additionally, LPBN ghrelin microinjection also significantly increased c-fos expression. Chronic ghrelin administration in the LPBN resulted in significantly increased body weight gain. Meanwhile, no significant changes were observed in both mRNA and protein expression levels of UCP-1 in BAT. These results demonstrated that microinjection of ghrelin in LPBN could increase food intake through the interaction with growth hormone secretagogue receptor (GHSR) in C57BL/6J mice, and its chronic administration could also increase body weight gain. These effects might be associated with altered firing rate in the GE and GI neurons.

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GABA neurons in the nucleus tractus solitarius express GLP-1 receptors and mediate anorectic effects of liraglutide in rats

Science Translational Medicine ◽

10.1126/scitranslmed.aay8071 ◽

2020 ◽

Vol 12 (533) ◽

pp. eaay8071 ◽

Cited By ~ 9

Author(s):

Samantha M. Fortin ◽

Rachele K. Lipsky ◽

Rinzin Lhamo ◽

Jack Chen ◽

Eun Kim ◽

...

Keyword(s):

Body Weight ◽

Food Intake ◽

Nucleus Tractus Solitarius ◽

Area Postrema ◽

Male Rats ◽

Glucagon Like Peptide 1 ◽

Treatment Of Obesity ◽

Cellular Phenotypes ◽

Sites Of Action

The glucagon-like peptide-1 receptor (GLP-1R) agonist liraglutide is approved for the treatment of obesity; however, there is still much to be learned regarding the neuronal sites of action that underlie its suppressive effects on food intake and body weight. Peripherally administered liraglutide in rats acts in part through central GLP-1Rs in both the hypothalamus and the hindbrain. Here, we extend findings supporting a role for hindbrain GLP-1Rs in mediating the anorectic effects of liraglutide in male rats. To dissociate the contribution of GLP-1Rs in the area postrema (AP) and the nucleus tractus solitarius (NTS), we examined the effects of liraglutide in both NTS AAV-shRNA–driven Glp1r knockdown and AP-lesioned animals. Knockdown of NTS GLP-1Rs, but not surgical lesioning of the AP, attenuated the anorectic and body weight–reducing effects of acutely delivered liraglutide. In addition, NTS c-Fos responses were maintained in AP-lesioned animals. Moreover, NTS Glp1r knockdown was sufficient to attenuate the intake- and body weight–reducing effects of chronic daily administered liraglutide over 3 weeks. Development of improved obesity pharmacotherapies requires an understanding of the cellular phenotypes targeted by GLP-1R agonists. Fluorescence in situ hybridization identified Glp1r transcripts in NTS GABAergic neurons, which when inhibited using chemogenetics, attenuated the food intake– and body weight–reducing effects of liraglutide. This work demonstrates the contribution of NTS GLP-1Rs to the anorectic potential of liraglutide and highlights a phenotypically distinct (GABAergic) population of neurons within the NTS that express the GLP-1R and are involved in the mediation of liraglutide signaling.

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Level of satiety: in vitro energy metabolism in brain during hypophagic and hyperphagic body weight recovery

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1989.257.6.r1322 ◽

1989 ◽

Vol 257 (6) ◽

pp. R1322-R1327 ◽

Cited By ~ 2

Author(s):

T. R. Kasser ◽

R. B. Harris ◽

R. J. Martin

Keyword(s):

Weight Loss ◽

Body Weight ◽

Fatty Acid ◽

Food Intake ◽

Fatty Acid Oxidation ◽

Glucose Oxidation ◽

Area Postrema ◽

Tube Feeding ◽

Acid Oxidation

Rates of in vitro glucose and fatty acid oxidation were examined in four brain sites during hypophagic and hyperphagic recovery of normal body weight. Rats were fed 40, 100, or 160% of normal intake, via gastric intubation, for 3 wk. Another group of rats was starved until body weight loss was equivalent to weight loss in 40%-fed rats. Groups of rats were killed at the conclusion of tube feeding or fasting and at specific periods during recovery of body weight. Brain sites examined were the ventrolateral hypothalamus (VLH), ventromedial hypothalamus (VMH), a caudal brain stem site encompassing the area postrema-nucleus of the solitary tract (AP-NTS), and cortex. During recovery, rats previously fed 160% of normal intake (anorectic) maintained low rates of VLH fatty acid oxidation and were hypophagic until most excess fat was depleted. Conversely, rats previously fed 40% of normal intake (hungry) maintained high rates of VLH fatty acid oxidation and were hyperphagic until most deficient fat was repleted. Rats previously starved maintained high rates of VLH fatty acid oxidation during hyperphagic recovery, although levels of VLH fatty acid oxidation and food intake were initially low on refeeding. Rates of glucose oxidation in the brain sites examined did not relate well to energy balance status and the needed adjustments in food intake. The results indicated that the level of glucose oxidation in the VLH and AP-NTS responded to the level of energy immediately coming into the system (food intake).(ABSTRACT TRUNCATED AT 250 WORDS)

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Area postrema mediates tumor effects on food intake, body weight, and learned aversions

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1985.249.3.r296 ◽

1985 ◽

Vol 249 (3) ◽

pp. R296-R300 ◽

Cited By ~ 1

Author(s):

I. L. Bernstein ◽

C. M. Treneer ◽

J. N. Kott

Keyword(s):

Body Weight ◽

Food Intake ◽

Leydig Cell ◽

Area Postrema ◽

Solitary Tract ◽

Medial Area

Growth of a Leydig cell [LTW (m)] tumor in rats is associated with the development of significant hypophagia and severe aversions to the available diet. Lesions of the area postrema and nearby caudal medial area of the solitary tract were found to block or greatly attenuate the anorexia and food aversions that typically accompany the growth of this tumor. Thus these tumor-induced symptoms may be associated with the detection of blood-borne chemicals by cells located in or near the area postrema.

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Functional and Neurochemical Identification of Ghrelin Receptor (GHSR)-Expressing Cells of the Lateral Parabrachial Nucleus in Mice

Frontiers in Neuroscience ◽

10.3389/fnins.2021.633018 ◽

2021 ◽

Vol 15 ◽

Author(s):

Marie V. Le May ◽

Fiona Peris-Sampedro ◽

Iris Stoltenborg ◽

Erik Schéle ◽

Tina Bake ◽

...

Keyword(s):

Body Weight ◽

Weight Gain ◽

Food Intake ◽

Food Choice ◽

Viral Vector ◽

Sucrose Solution ◽

Parabrachial Nucleus ◽

Growth Hormone Secretagogue ◽

Lateral Parabrachial Nucleus ◽

Obesogenic Diet

The lateral parabrachial nucleus (lPBN), located in the pons, is a well-recognized anorexigenic center harboring, amongst others, the calcitonin gene-related peptide (CGRP)-expressing neurons that play a key role. The receptor for the orexigenic hormone ghrelin (the growth hormone secretagogue receptor, GHSR) is also abundantly expressed in the lPBN and ghrelin delivery to this site has recently been shown to increase food intake and alter food choice. Here we sought to explore whether GHSR-expressing cells in the lPBN (GHSRlPBN cells) contribute to feeding control, food choice and body weight gain in mice offered an obesogenic diet, involving studies in which GHSRlPBN cells were silenced. We also explored the neurochemical identity of GHSRlPBN cells. To silence GHSRlPBN cells, Ghsr-IRES-Cre male mice were bilaterally injected intra-lPBN with a Cre-dependent viral vector expressing tetanus toxin-light chain. Unlike control wild-type littermates that significantly increased in body weight on the obesogenic diet (i.e., high-fat high-sugar free choice diet comprising chow, lard and 9% sucrose solution), the heterozygous mice with silenced GHSRlPBN cells were resistant to diet-induced weight gain with significantly lower food intake and fat weight. The lean phenotype appeared to result from a decreased food intake compared to controls and caloric efficiency was unaltered. Additionally, silencing the GHSRlPBN cells altered food choice, significantly reducing palatable food consumption. RNAscope and immunohistochemical studies of the lPBN revealed considerable co-expression of GHSR with glutamate and pituitary adenylate cyclase-activating peptide (PACAP), and much less with neurotensin, substance P and CGRP. Thus, the GHSRlPBN cells are important for diet-induced weight gain and adiposity, as well as in the regulation of food intake and food choice. Most GHSRlPBN cells were found to be glutamatergic and the majority (76%) do not belong to the well-characterized anorexigenic CGRP cell population.

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GIP Receptor Agonism Attenuates GLP-1 Receptor Agonist Induced Nausea and Emesis in Preclinical Models

10.2337/figshare.15125112 ◽

2021 ◽

Author(s):

Tito Borner ◽

Caroline E. Geisler ◽

Samantha M. Fortin ◽

Richard Cosgrove ◽

Jorge Alsina-Fernandez ◽

...

Keyword(s):

Body Weight ◽

Food Intake ◽

Nucleus Tractus Solitarius ◽

Area Postrema ◽

Body Weight Loss ◽

Diabetes Patient ◽

Obesity And Diabetes ◽

Nausea And Emesis ◽

Glucagon Like Peptide 1 ◽

Cellular Phenotypes

Glucagon-like peptide-1 receptor (GLP-1R) agonists decrease body weight and improve glycemic control in obesity and diabetes. Patient compliance and maximal efficacy of GLP-1 therapeutics are limited by side effects including nausea and emesis. In three different species (i.e., mice, rats, and musk shrews), we show that glucose-dependent insulinotropic polypeptide receptor (GIPR) signaling blocks emesis and attenuates illness behaviors elicited by GLP-1R activation, while maintaining reduced food intake, body weight loss, and improved glucose tolerance. The area postrema and nucleus tractus solitarius (AP/NTS) of the hindbrain are required for food intake and body weight suppression by GLP-1R ligands and processing of emetic stimuli. Utilizing single-nuclei RNA-sequencing, we identified the cellular phenotypes of AP/NTS GIPR- and GLP-1R-expressing cells on distinct populations of inhibitory and excitatory neurons, with the greatest expression of GIPR in GABAergic neurons. This work suggests that combinatorial pharmaceutical targeting of GLP-1R and GIPR will increase efficacy in treating obesity and diabetes by reducing nausea and vomiting.

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The cytokine GDF15 signals through a population of brainstem cholecystokinin neurons to mediate anorectic signalling

eLife ◽

10.7554/elife.55164 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 2

Author(s):

Amy A Worth ◽

Rosemary Shoop ◽

Katie Tye ◽

Claire H Feetham ◽

Giuseppe D'Agostino ◽

...

Keyword(s):

Monoclonal Antibody ◽

Body Weight ◽

Food Intake ◽

Weight Reduction ◽

Area Postrema ◽

Metabolic Effects ◽

Therapeutic Drug ◽

Neutralising Antibodies ◽

Neuronal Signalling ◽

Pre Treatment

The cytokine, GDF15, is produced in pathological states which cause cellular stress, including cancer. When over expressed, it causes dramatic weight reduction, suggesting a role in disease-related anorexia. Here, we demonstrate that the GDF15 receptor, GFRAL, is located in a subset of cholecystokinin neurons which span the area postrema and the nucleus of the tractus solitarius of the mouse. GDF15 activates GFRALAP/NTS neurons and supports conditioned taste and place aversions, while the anorexia it causes can be blocked by a monoclonal antibody directed at GFRAL or by disrupting CCK neuronal signalling. The cancer-therapeutic drug, cisplatin, induces the release of GDF15 and activates GFRALAP/NTS neurons, as well as causing significant reductions in food intake and body weight in mice. These metabolic effects of cisplatin are abolished by pre-treatment with the GFRAL monoclonal antibody. Our results suggest that GFRAL neutralising antibodies or antagonists may provide a co-treatment opportunity for patients undergoing chemotherapy.

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