scholarly journals Central 5-HTR2C in the Control of Metabolic Homeostasis

2021 ◽  
Vol 12 ◽  
Author(s):  
Ting Yao ◽  
Jiehui He ◽  
Zhicheng Cui ◽  
Ruwen Wang ◽  
Kaixuan Bao ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Metabolic Regulation ◽  
Metabolic Disorders ◽  
Energy Homeostasis ◽  
Molecular Pathways ◽  
Metabolic Hormones ◽  
Obesity Drugs ◽  
G Protein Coupled ◽  
The Brain

The 5-hydroxytryptamine 2C receptor (5-HTR2C) is a class G protein-coupled receptor (GPCR) enriched in the hypothalamus and the brain stem, where it has been shown to regulate energy homeostasis, including feeding and glucose metabolism. Accordingly, 5-HTR2C has been the target of several anti-obesity drugs, though the associated side effects greatly curbed their clinical applications. Dissecting the specific neural circuits of 5-HTR2C-expressing neurons and the detailed molecular pathways of 5-HTR2C signaling in metabolic regulation will help to develop better therapeutic strategies towards metabolic disorders. In this review, we introduced the regulatory role of 5-HTR2C in feeding behavior and glucose metabolism, with particular focus on the molecular pathways, neural network, and its interaction with other metabolic hormones, such as leptin, ghrelin, insulin, and estrogens. Moreover, the latest progress in the clinical research on 5-HTR2C agonists was also discussed.

scholarly journals Gpr17 signaling decreases GLP-1 secretion in GLUTag cells

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Katherine Stalbaum ◽  
Shijun Yan ◽  
Hongxia Ren
Keyword(s):  
Metabolic Regulation ◽  
Enteroendocrine Cells ◽  
Incretin Hormone ◽  
Obesity And Diabetes ◽  
The Media ◽  
Glucagon Like Peptide 1 ◽  
The Difference ◽  
G Protein Coupled ◽  
The Brain

Background and Hypothesis: The incidence of obesity and diabetes continues to rise in devastatingly high proportions, making the need for safe, affordable, and effective treatment increasingly apparent. We discovered that the orphan G protein-coupled receptor 17 (Gpr17) is expressed in endocrine cells in the brain and gut and may have an important role in metabolic regulation. Glucagon-like peptide 1 (GLP-1), an incretin hormone secreted from enteroendocrine cells, is a strong insulin secretagogue and suppresses appetite. We hypothesized that Gpr17 signaling decreases GLP-1 secretion in gut enteroendocrine cells. Experimental Design or Project Methods: In order to investigate the role of Gpr17 in GLP-1 secretion, we measured GLP-1 secretion in a murine enteroendocrine cell line (GLUTag cells) that expresses Gpr17 and the proglucagon gene and secretes GLP-1 in a regulated manner. GLUTag cells were stimulated with glucose or lipid, oleoyl-lysophosphatidylcholine (LPC), in the presence or absence of MDL29,951, a synthetic Gpr17 agonist. After a 2-hour incubation, we measured GLP-1 in the media and cell lysates to determine the percentage of secreted GLP-1. Results: Cells treated with glucose and MDL29,951 had decreased GLP-1 secretion compared to glucose alone, however, the difference was not significant. Cells treated with LPC and MDL29,951 had a significant decrease in GLP-1 secretion compared to LPC alone. Conclusion and Potential Impact: Gpr17 activation by MDL29,951 decreased GLP-1 secretion in GLUTag cells stimulated by both glucose and lipid, which supports our hypothesis that Gpr17 signaling regulates GLP-1 secretion. Therefore, Gpr17 may be a potential pharmacological target for combating obesity and diabetes.

scholarly journals Adipose Tissue Immunomodulation and Treg/Th17 Imbalance in the Impaired Glucose Metabolism of Children with Obesity

Children ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 554
Author(s):  
Stefania Croce ◽  
Maria Antonietta Avanzini ◽  
Corrado Regalbuto ◽  
Erika Cordaro ◽  
Federica Vinci ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Glucose Metabolism ◽  
Th17 Cells ◽  
Metabolic Disorders ◽  
Potential Role ◽  
Immune Monitoring ◽  
Metabolic Dysfunction ◽  
Impaired Glucose Metabolism ◽  
T Cell Infiltration

In the last few decades, obesity has increased dramatically in pediatric patients. Obesity is a chronic disease correlated with systemic inflammation, characterized by the presence of CD4 and CD8 T cell infiltration and modified immune response, which contributes to the development of obesity related diseases and metabolic disorders, including impaired glucose metabolism. In particular, Treg and Th17 cells are dynamically balanced under healthy conditions, but imbalance occurs in inflammatory and pathological states, such as obesity. Some studies demonstrated that peripheral Treg and Th17 cells exhibit increased imbalance with worsening of glucose metabolic dysfunction, already in children with obesity. In this review, we considered the role of adipose tissue immunomodulation and the potential role played by Treg/T17 imbalance on the impaired glucose metabolism in pediatric obesity. In the patient care, immune monitoring could play an important role to define preventive strategies of pediatric metabolic disease treatments.

The Role of Tanycytes in the Hypothalamus-Pituitary-Thyroid Axis and the Possibilities for Their Genetic Manipulation

2019 ◽  
Vol 128 (06/07) ◽  
pp. 388-394
Author(s):  
Helge Müller-Fielitz ◽  
Markus Schwaninger
Keyword(s):  
Energy Homeostasis ◽  
Genetic Manipulation ◽  
Heart Function ◽  
Feedback Regulation ◽  
Target Organs ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Hpt Axis ◽  
The Brain

AbstractThyroid hormone (TH) regulation is important for development, energy homeostasis, heart function, and bone formation. To control the effects of TH in target organs, the hypothalamus-pituitary-thyroid (HPT) axis and the tissue-specific availability of TH are highly regulated by negative feedback. To exert a central feedback, TH must enter the brain via specific transport mechanisms and cross the blood-brain barrier. Here, tanycytes, which are located in the ventral walls of the 3rd ventricle in the mediobasal hypothalamus (MBH), function as gatekeepers. Tanycytes are able to transport, sense, and modify the release of hormones of the HPT axis and are involved in feedback regulation. In this review, we focus on the relevance of tanycytes in thyrotropin-releasing hormone (TRH) release and review available genetic tools to investigate the physiological functions of these cells.

scholarly journals The Role of High Fat Diets and Liver Peptidase Activity in the Development of Obesity and Insulin Resistance in Wistar Rats

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 636
Author(s):  
Germán Domínguez-Vías ◽  
Ana Belén Segarra ◽  
Manuel Ramírez-Sánchez ◽  
Isabel Prieto
Keyword(s):  
Glucose Metabolism ◽  
Wistar Rats ◽  
Metabolic Disorders ◽  
Peptidase Activity ◽  
High Fat ◽  
Β Cell ◽  
High Fat Diets ◽  
Glutamyl Transferase ◽  
Fat Diets

High-fat diets (HFD) have been widely associated with an increased risk of metabolic disorders and overweight. However, a high intake of sources that are rich in monounsaturated fatty acids has been suggested as a dietary agent that is able to positively influence energy metabolism and vascular function. The main objective of this study was to analyze the role of dietary fats on hepatic peptidases activities and metabolic disorders. Three diets: standard (S), HFD supplemented with virgin olive oil (VOO), and HFD supplemented with butter plus cholesterol (Bch), were administered over six months to male Wistar rats. Plasma and liver samples were collected for clinical biochemistry and aminopeptidase activities (AP) analysis. The expression of inducible nitric oxide synthase (iNOS) was also determined by Western blot in liver samples. The diet supplement with VOO did not induce obesity, in contrast to the Bch group. Though the VOO diet increased the time that was needed to return to the basal levels of plasma glucose, the fasting insulin/glucose ratio and HOMA2-%B index (a homeostasis model index of insulin secretion and valuation of β-cell usefulness (% β-cell secretion)) were improved. An increase of hepatic membrane-bound dipeptidyl-peptidase 4 (DPP4) activity was found only in VOO rats, even if no differences in fasting plasma glucagon-like peptide 1 (GLP-1) were obtained. Both HFDs induced changes in hepatic pyroglutamyl-AP in the soluble fraction, but only the Bch diet increased the soluble tyrosyl-AP. Angiotensinase activities that are implicated in the metabolism of angiotensin II (AngII) to AngIV increased in the VOO diet, which was in agreement with the higher activity of insulin-regulated-AP (IRAP) in this group. Otherwise, the diet that was enriched with butter increased soluble gamma-glutamyl transferase (GGT) and Leucyl-AP, iNOS expression in the liver, and plasma NO. In summary, VOO increased the hepatic activity of AP that were related to glucose metabolism (DPP4, angiotensinases, and IRAP). However, the Bch diet increased activities that are implicated in the control of food intake (Tyrosine-AP), the index of hepatic damage (Leucine-AP and GGT), and the expression of hepatic iNOS and plasma NO. Taken together, these results support that the source of fat in the diet affects several peptidases activities in the liver, which could be related to alterations in feeding behavior and glucose metabolism.

scholarly journals Neural Underpinnings of Obesity: The Role of Oxidative Stress and Inflammation in the Brain

Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1018
Author(s):  
Caitlyn A. Mullins ◽  
Ritchel B. Gannaban ◽  
Md Shahjalal Khan ◽  
Harsh Shah ◽  
Md Abu B. Siddik ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Energy Homeostasis ◽  
Dorsal Striatum ◽  
Brain Regions ◽  
Therapeutic Interventions ◽  
Low Grade ◽  
Obesity Prevalence ◽  
Beneficial Effects ◽  
The Brain

Obesity prevalence is increasing at an unprecedented rate throughout the world, and is a strong risk factor for metabolic, cardiovascular, and neurological/neurodegenerative disorders. While low-grade systemic inflammation triggered primarily by adipose tissue dysfunction is closely linked to obesity, inflammation is also observed in the brain or the central nervous system (CNS). Considering that the hypothalamus, a classical homeostatic center, and other higher cortical areas (e.g. prefrontal cortex, dorsal striatum, hippocampus, etc.) also actively participate in regulating energy homeostasis by engaging in inhibitory control, reward calculation, and memory retrieval, understanding the role of CNS oxidative stress and inflammation in obesity and their underlying mechanisms would greatly help develop novel therapeutic interventions to correct obesity and related comorbidities. Here we review accumulating evidence for the association between ER stress and mitochondrial dysfunction, the main culprits responsible for oxidative stress and inflammation in various brain regions, and energy imbalance that leads to the development of obesity. Potential beneficial effects of natural antioxidant and anti-inflammatory compounds on CNS health and obesity are also discussed.

scholarly journals Evidence of the Role of Omega-3 Polyunsaturated Fatty Acids in Brain Glucose Metabolism

Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1382
Author(s):  
Fabien Pifferi ◽  
Stephen C. Cunnane ◽  
Philippe Guesnet
Keyword(s):  
Fatty Acids ◽  
Glucose Metabolism ◽  
Polyunsaturated Fatty Acids ◽  
Brain Function ◽  
High Energy ◽  
Brain Glucose ◽  
Brain Glucose Metabolism ◽  
Age Related ◽  
The Brain

In mammals, brain function, particularly neuronal activity, has high energy needs. When glucose is supplemented by alternative oxidative substrates under different physiological conditions, these fuels do not fully replace the functions fulfilled by glucose. Thus, it is of major importance that the brain is almost continuously supplied with glucose from the circulation. Numerous studies describe the decrease in brain glucose metabolism during healthy or pathological ageing, but little is known about the mechanisms that cause such impairment. Although it appears difficult to determine the exact role of brain glucose hypometabolism during healthy ageing or during age-related neurodegenerative diseases such as Alzheimer’s disease, uninterrupted glucose supply to the brain is still of major importance for proper brain function. Interestingly, a body of evidence suggests that dietary n-3 polyunsaturated fatty acids (PUFAs) might play significant roles in brain glucose regulation. Thus, the goal of the present review is to summarize this evidence and address the role of n-3 PUFAs in brain energy metabolism. Taken together, these data suggest that ensuring an adequate dietary supply of n-3 PUFAs could constitute an essential aspect of a promising strategy to promote optimal brain function during both healthy and pathological ageing.

scholarly journals The Antiobesity Effects of Centrally Administered Neuromedin U and Neuromedin S Are Mediated Predominantly by the Neuromedin U Receptor 2 (NMUR2)

Endocrinology ◽  
2009 ◽  
Vol 150 (7) ◽  
pp. 3101-3109 ◽  
Author(s):  
Andrea Peier ◽  
Jennifer Kosinski ◽  
Kimberly Cox-York ◽  
Ying Qian ◽  
Kunal Desai ◽  
...  
Keyword(s):  
Food Intake ◽  
Energy Homeostasis ◽  
Central Administration ◽  
Diet Induced Obesity ◽  
Inhibit Food Intake ◽  
Selective Agonists ◽  
Treatment Of Obesity ◽  
The Brain ◽  
Deficient Mice

Neuromedin U (NMU) and neuromedin S (NMS) are structurally related neuropeptides that have been reported to modulate energy homeostasis. Pharmacological data have shown that NMU and NMS inhibit food intake when administered centrally and that NMU increases energy expenditure. Additionally, NMU-deficient mice develop obesity, whereas transgenic mice overexpressing NMU are lean and hypophagic. Two high-affinity NMU/NMS receptors, NMUR1 and NMUR2, have been identified. NMUR1 is predominantly expressed in the periphery, whereas NMUR2 is predominantly expressed in the brain, suggesting that the effects of centrally administered NMU and NMS are mediated by NMUR2. To evaluate the role of NMUR2 in the regulation of energy homeostasis, we characterized NMUR2-deficient (Nmur2−/−) mice. Nmur2−/− mice exhibited a modest resistance to diet-induced obesity that was at least in part due to reduced food intake. Acute central administration of NMU and NMS reduced food intake in wild-type but not in Nmur2−/− mice. The effects on activity and core temperature induced by centrally administered NMU were also absent in Nmur2−/− mice. Moreover, chronic central administration of NMU and NMS evoked significant reductions in body weight and sustained reductions in food intake in mice. In contrast, Nmur2−/− mice were largely resistant to these effects. Collectively, these data demonstrate that the anorectic and weight-reducing actions of centrally administered NMU and NMS are mediated predominantly by NMUR2, suggesting that NMUR2-selective agonists may be useful for the treatment of obesity.

The role of amylin in the control of energy homeostasis

2010 ◽  
Vol 298 (6) ◽  
pp. R1475-R1484 ◽  
Author(s):  
Thomas A. Lutz
Keyword(s):  
Energy Homeostasis ◽  
Area Postrema ◽  
Body Weight Gain ◽  
Direct Action ◽  
Central Administration ◽  
Experimental Conditions ◽  
Hypothalamic Area ◽  
Chronic Infusion ◽  
The Brain

Amylin is an important player in the control of nutrient fluxes. Amylin reduces eating via a meal size effect by promoting meal-ending satiation. This effect seems to depend on a direct action in the area postrema (AP), which is an area rich in amylin receptors. Subsequent to the activation of AP neurons, the neural signal is conveyed to the forebrain via relays involving the nucleus of the solitary tract (NTS) and the lateral parabrachial nucleus (lPBN) to the lateral hypothalamic area (LHA) and other hypothalamic nuclei. While the NTS and lPBN seem to be necessary for amylin's eating inhibitory effect, the role of the LHA has not yet been fully investigated. Amylin may also act as an adiposity signal. Plasma levels of amylin are higher in obese individuals, and chronic infusion of amylin into the brain reduces body weight gain and adiposity; chronic infusion of an amylin receptor antagonist into the brain increases body adiposity. Amylin increases energy expenditure in rats; this effect occurs under various experimental conditions after peripheral and central administration. Together, these animal data, but also clinical data in humans, indicate that amylin is a promising candidate for the treatment of obesity; effects are most pronounced when amylin is combined with leptin. Finally, recent findings indicate that amylin acts as a neurotrophic factor in specific brain stem areas. Whether this effect may be relevant under physiological conditions requires further studies.

scholarly journals Wnt5a Increases the Glycolytic Rate and the Activity of the Pentose Phosphate Pathway in Cortical Neurons

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Pedro Cisternas ◽  
Paulina Salazar ◽  
Carmen Silva-Álvarez ◽  
L. Felipe Barros ◽  
Nibaldo C. Inestrosa
Keyword(s):  
Glucose Metabolism ◽  
Wnt Signaling ◽  
Pentose Phosphate Pathway ◽  
Neurodegenerative Disorders ◽  
Metabolic Flux ◽  
High Energy ◽  
Pentose Phosphate ◽  
The Brain ◽  
Glycolytic Rate

In the last few years, several reports have proposed that Wnt signaling is a general metabolic regulator, suggesting a role for this pathway in the control of metabolic flux. Wnt signaling is critical for several neuronal functions, but little is known about the correlation between this pathway and energy metabolism. The brain has a high demand for glucose, which is mainly used for energy production. Neurons use energy for highly specific processes that require a high energy level, such as maintaining the electrical potential and synthesizing neurotransmitters. Moreover, an important metabolic impairment has been described in all neurodegenerative disorders. Despite the key role of glucose metabolism in the brain, little is known about the cellular pathways involved in regulating this process. We report here that Wnt5a induces an increase in glucose uptake and glycolytic rate and an increase in the activity of the pentose phosphate pathway; the effects of Wnt5a require the intracellular generation of nitric oxide. Our data suggest that Wnt signaling stimulates neuronal glucose metabolism, an effect that could be important for the reported neuroprotective role of Wnt signaling in neurodegenerative disorders.

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