1
|
Lee J, Kim WK. Applications of Enteroendocrine Cells (EECs) Hormone: Applicability on Feed Intake and Nutrient Absorption in Chickens. Animals (Basel) 2023; 13:2975. [PMID: 37760373 PMCID: PMC10525316 DOI: 10.3390/ani13182975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/09/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
This review focuses on the role of hormones derived from enteroendocrine cells (EECs) on appetite and nutrient absorption in chickens. In response to nutrient intake, EECs release hormones that act on many organs and body systems, including the brain, gallbladder, and pancreas. Gut hormones released from EECs play a critical role in the regulation of feed intake and the absorption of nutrients such as glucose, protein, and fat following feed ingestion. We could hypothesize that EECs are essential for the regulation of appetite and nutrient absorption because the malfunction of EECs causes severe diarrhea and digestion problems. The importance of EEC hormones has been recognized, and many studies have been carried out to elucidate their mechanisms for many years in other species. However, there is a lack of research on the regulation of appetite and nutrient absorption by EEC hormones in chickens. This review suggests the potential significance of EEC hormones on growth and health in chickens under stress conditions induced by diseases and high temperature, etc., by providing in-depth knowledge of EEC hormones and mechanisms on how these hormones regulate appetite and nutrient absorption in other species.
Collapse
Affiliation(s)
| | - Woo Kyun Kim
- Department of Poultry Science, University of Georgia, Athens, GA 30602, USA;
| |
Collapse
|
2
|
Tu W, Zhang Y, Jiang K, Jiang S. Osteocalcin and Its Potential Functions for Preventing Fatty Liver Hemorrhagic Syndrome in Poultry. Animals (Basel) 2023; 13:ani13081380. [PMID: 37106943 PMCID: PMC10135196 DOI: 10.3390/ani13081380] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/20/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
Osteocalcin (OCN) is synthesized and secreted by differentiating osteoblasts. In addition to its role in bone, OCN acts as a hormone in the pancreas, liver, muscle, fat, and other organs to regulate multiple pathophysiological processes including glucose homeostasis and adipic acid metabolism. Fat metabolic disorder, such as excessive fat buildup, is related to non-alcoholic fatty liver disease (NAFLD) in humans. Similarly, fatty liver hemorrhage syndrome (FLHS) is a metabolic disease in laying hens, resulting from lipid accumulation in hepatocytes. FLHS affects hen health with significant impact on poultry egg production. Many studies have proposed that OCN has protective function in mammalian NAFLD, but its function in chicken FLHS and related mechanism have not been completely clarified. Recently, we have revealed that OCN prevents laying hens from FLHS through regulating the JNK pathway, and some pathways related to the disease progression have been identified through both in vivo and vitro investigations. In this view, we discussed the current findings for predicting the strategy for using OCN to prevent or reduce FLHS impact on poultry production.
Collapse
Affiliation(s)
- Wenjun Tu
- Joint International Research Laboratory of Animal Health and Animal Food Safety, College of Veterinary Medicine, Southwest University, Chongqing 400715, China
| | - Yuhan Zhang
- Joint International Research Laboratory of Animal Health and Animal Food Safety, College of Veterinary Medicine, Southwest University, Chongqing 400715, China
| | - Kunyu Jiang
- Joint International Research Laboratory of Animal Health and Animal Food Safety, College of Veterinary Medicine, Southwest University, Chongqing 400715, China
| | - Sha Jiang
- Joint International Research Laboratory of Animal Health and Animal Food Safety, College of Veterinary Medicine, Southwest University, Chongqing 400715, China
- Immunology Research Center, Medical Research Institute, Southwest University, Chongqing 402460, China
| |
Collapse
|
3
|
Sweazea KL. Revisiting glucose regulation in birds - A negative model of diabetes complications. Comp Biochem Physiol B Biochem Mol Biol 2022; 262:110778. [PMID: 35817273 DOI: 10.1016/j.cbpb.2022.110778] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 07/01/2022] [Accepted: 07/05/2022] [Indexed: 11/19/2022]
Abstract
Birds naturally have blood glucose concentrations that are nearly double levels measured for mammals of similar body size and studies have shown that birds are resistant to insulin-mediated glucose uptake into tissues. While a combination of high blood glucose and insulin resistance is associated with diabetes-related pathologies in mammals, birds do not develop such complications. Moreover, studies have shown that birds are resistant to oxidative stress and protein glycation and in fact, live longer than similar-sized mammals. This review seeks to explore how birds regulate blood glucose as well as various theories that might explain their apparent resistance to insulin-mediated glucose uptake and adaptations that enable them to thrive in a state of relative hyperglycemia.
Collapse
|
4
|
Zhang JM, Sun YS, Zhao LQ, Chen TT, Fan MN, Jiao HC, Zhao JP, Wang XJ, Li FC, Li HF, Lin H. SCFAs-Induced GLP-1 Secretion Links the Regulation of Gut Microbiome on Hepatic Lipogenesis in Chickens. Front Microbiol 2019; 10:2176. [PMID: 31616396 PMCID: PMC6775471 DOI: 10.3389/fmicb.2019.02176] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 09/05/2019] [Indexed: 12/14/2022] Open
Abstract
The impact of gut microbiota and its metabolites on fat metabolism have been widely reported in human and animals. However, the critical mediators and the signal transductions are not well demonstrated. As ovipara, chicken represents a specific case in lipid metabolism that liver is the main site of lipid synthesis. The aim of this study is to elucidate the linkage of gut microbiota and fat synthesis in broiler chickens. The broilers were subjected to dietary treatments of combined probiotics (Animal bifidobacterium: 4 × 108 cfu/kg; Lactobacillus plantarum: 2 × 108 cfu/kg; Enterococcus faecalis: 2 × 108 cfu/kg; Clostridium butyrate: 2 × 108 cfu/kg, PB) and guar gum (1 g/kg, GG), respectively. Results showed that dietary supplementation of PB and GG changed the cecal microbiota diversity, altered short chain fatty acids (SCFAs) contents, and suppressed lipogenesis. In intestinal epithelial cells (IECs), SCFAs (acetate, propionate, and butyrate) up-regulated the expression of glucagon-like peptide-1 (GLP-1) via mitogen-activated protein kinase (MAPK) pathways, mainly via the phospho - extracellular regulated protein kinase (ERK) and phospho-p38 mitogen activated protein kinase (p38 MAPK) pathways. GLP-1 suppressed lipid accumulation in primary hepatocytes with the involvement of (AMP)-activated protein kinase/Acetyl CoA carboxylase (AMPK/ACC) signaling. In conclusion, the result suggests that SCFAs-induced GLP-1 secretion via MAPK pathway, which links the regulation of gut microbiota on hepatic lipogenesis in chickens.
Collapse
Affiliation(s)
- Jian-Mei Zhang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Key Laboratory of Animal Microecological Agents, Biological Research Institute, Shandong Baolai-Leelai Bioengineering Co., Ltd., Tai'an, China
| | - Yin-Shuang Sun
- Shandong Key Laboratory of Animal Microecological Agents, Biological Research Institute, Shandong Baolai-Leelai Bioengineering Co., Ltd., Tai'an, China
| | - Li-Qin Zhao
- College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Tian-Tian Chen
- Shandong Key Laboratory of Animal Microecological Agents, Biological Research Institute, Shandong Baolai-Leelai Bioengineering Co., Ltd., Tai'an, China
| | - Mei-Na Fan
- Shandong Key Laboratory of Animal Microecological Agents, Biological Research Institute, Shandong Baolai-Leelai Bioengineering Co., Ltd., Tai'an, China
| | - Hong-Chao Jiao
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Jing-Peng Zhao
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Xiao-Juan Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Fu-Chang Li
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Hai-Fang Li
- College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Hai Lin
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| |
Collapse
|
5
|
Abtahi S, Howell E, Salvucci JT, Bastacky JMR, Dunn DP, Currie PJ. Exendin-4 antagonizes the metabolic action of acylated ghrelinergic signaling in the hypothalamic paraventricular nucleus. Gen Comp Endocrinol 2019; 270:75-81. [PMID: 30336120 PMCID: PMC6886705 DOI: 10.1016/j.ygcen.2018.10.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 09/19/2018] [Accepted: 10/14/2018] [Indexed: 12/11/2022]
Abstract
In the current study we investigated the interaction of hypothalamic paraventricular nucleus (PVN) glucagon-like peptide-1 (GLP-1) and ghrelin signaling in the control of metabolic function. We first demonstrated that acylated ghrelin injected directly into the PVN reliably altered the respiratory exchange ratio (RER) of adult male Sprague Dawley rats. All testing was carried out during the initial 2 h of the nocturnal cycle using an indirect open circuit calorimeter. Results indicated that acylated ghrelin induced a robust increase in RER representing a shift toward enhanced carbohydrate oxidation and reduced lipid utilization. In contrast, treatment with comparable dosing of des-acyl ghrelin failed to significantly impact metabolic activity. In separate groups of rats we subsequently investigated the ability of exendin-4 (Ex-4), a GLP-1 analogue, to alter acylated ghrelin's metabolic effects. Rodents were treated with either systemic or direct PVN Ex-4 followed by acyl ghrelin microinjection. While our results showed that both systemic and PVN administration of Ex-4 significantly reduced RER, importantly, Ex-4 pretreatment itself reliably inhibited the impact of ghrelin on RER. Overall, these findings provide increasingly compelling evidence that GLP-1 and ghrelin signaling interact in the neural control of metabolic function within the PVN.
Collapse
Affiliation(s)
- Shayan Abtahi
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, United States
| | - Erin Howell
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, United States
| | - Jack T Salvucci
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, United States
| | - Joshua M R Bastacky
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, United States
| | - David P Dunn
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, United States
| | - Paul J Currie
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, United States.
| |
Collapse
|
6
|
Kooijman S, Wang Y, Parlevliet ET, Boon MR, Edelschaap D, Snaterse G, Pijl H, Romijn JA, Rensen PCN. Central GLP-1 receptor signalling accelerates plasma clearance of triacylglycerol and glucose by activating brown adipose tissue in mice. Diabetologia 2015; 58:2637-46. [PMID: 26254578 PMCID: PMC4589565 DOI: 10.1007/s00125-015-3727-0] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 07/23/2015] [Indexed: 12/21/2022]
Abstract
AIMS/HYPOTHESIS Glucagon-like peptide 1 (GLP-1) receptor (GLP-1R) agonism, used in the treatment of type 2 diabetes, has recently been shown to increase thermogenesis via the brain. As brown adipose tissue (BAT) produces heat by burning triacylglycerol (TG) and takes up glucose for de novo lipogenesis, the aim of this study was to evaluate the potential of chronic central GLP-1R activation by exendin-4 to facilitate clearance of lipids and glucose from the circulation by activating BAT. METHODS Lean and diet-induced obese (DIO) C57Bl/6J mice were used to explore the effect of a 5 day intracerebroventricular infusion of the GLP-1 analogue exendin-4 or vehicle on lipid and glucose uptake by BAT in both insulin-sensitive and insulin-resistant conditions. RESULTS Central administration of exendin-4 in lean mice increased sympathetic outflow towards BAT and white adipose tissue (WAT), resulting in increased thermogenesis as evidenced by increased uncoupling protein 1 (UCP-1) protein levels and decreased lipid content, while the uptake of TG-derived fatty acids was increased in both BAT and WAT. Interestingly, in DIO mice, the effects on WAT were blunted, while exendin-4 still increased sympathetic outflow towards BAT and increased the uptake of plasma TG-derived fatty acids and glucose by BAT. These effects were accompanied by increased fat oxidation, lower plasma TG and glucose concentrations, and reduced body weight. CONCLUSIONS/INTERPRETATION Collectively, our results suggest that BAT activation may be a major contributor to the glucose- and TG-lowering effects of GLP-1R agonism.
Collapse
Affiliation(s)
- Sander Kooijman
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Room C7-Q44, Albinusdreef 2, PO Box 9600, 2300, RC, Leiden, the Netherlands.
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands.
| | - Yanan Wang
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Room C7-Q44, Albinusdreef 2, PO Box 9600, 2300, RC, Leiden, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Edwin T Parlevliet
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Room C7-Q44, Albinusdreef 2, PO Box 9600, 2300, RC, Leiden, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
- Department of Medicine, Academic Medical Center, Amsterdam, the Netherlands
| | - Mariëtte R Boon
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Room C7-Q44, Albinusdreef 2, PO Box 9600, 2300, RC, Leiden, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - David Edelschaap
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Room C7-Q44, Albinusdreef 2, PO Box 9600, 2300, RC, Leiden, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Gido Snaterse
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Room C7-Q44, Albinusdreef 2, PO Box 9600, 2300, RC, Leiden, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Hanno Pijl
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Room C7-Q44, Albinusdreef 2, PO Box 9600, 2300, RC, Leiden, the Netherlands
| | - Johannes A Romijn
- Department of Medicine, Academic Medical Center, Amsterdam, the Netherlands
| | - Patrick C N Rensen
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Room C7-Q44, Albinusdreef 2, PO Box 9600, 2300, RC, Leiden, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| |
Collapse
|
7
|
Honda K, Saneyasu T, Shimatani T, Aoki K, Yamaguchi T, Nakanishi K, Kamisoyama H. Intracerebroventricular administration of chicken glucagon-like peptide-2 potently suppresses food intake in chicks. Anim Sci J 2014; 86:312-8. [DOI: 10.1111/asj.12282] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 06/11/2014] [Indexed: 12/23/2022]
Affiliation(s)
- Kazuhisa Honda
- Department of Bioresource Science; Graduate School of Agricultural Science; Kobe University; Kobe Japan
| | - Takaoki Saneyasu
- Department of Bioresource Science; Graduate School of Agricultural Science; Kobe University; Kobe Japan
| | - Tomohiko Shimatani
- Department of Bioresource Science; Graduate School of Agricultural Science; Kobe University; Kobe Japan
| | - Koji Aoki
- Department of Bioresource Science; Graduate School of Agricultural Science; Kobe University; Kobe Japan
| | - Takuya Yamaguchi
- Department of Bioresource Science; Graduate School of Agricultural Science; Kobe University; Kobe Japan
| | - Kiwako Nakanishi
- Department of Bioresource Science; Graduate School of Agricultural Science; Kobe University; Kobe Japan
| | - Hiroshi Kamisoyama
- Department of Bioresource Science; Graduate School of Agricultural Science; Kobe University; Kobe Japan
| |
Collapse
|
8
|
Honda K, Saneyasu T, Yamaguchi T, Shimatani T, Aoki K, Nakanishi K, Kamisoyama H. Intracerebroventricular administration of novel glucagon-like peptide suppresses food intake in chicks. Peptides 2014; 52:98-103. [PMID: 24361510 DOI: 10.1016/j.peptides.2013.12.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 12/11/2013] [Accepted: 12/11/2013] [Indexed: 11/29/2022]
Abstract
Glucagon-related peptides such as glucagon, glucagon-like peptide-1, and oxyntomodulin suppress food intake in mammals and birds. Recently, novel glucagon-like peptide (GCGL) was identified from chicken brain, and a comparatively high mRNA expression level of GCGL was detected in the hypothalamus. A number of studies suggest that the hypothalamus plays a critical role in the regulation of food intake in mammals and birds. In the present study, we investigated whether GCGL is involved in the central regulation of food intake in chicks. Male 8-day-old chicks (Gallus gallus) were used in all experiments. Intracerebroventricular administration of GCGL in chicks significantly suppressed food intake. Plasma glucose level was significantly decreased by GCGL, whereas plasma corticosterone level was not affected. Central administration of a corticotrophin-releasing factor (CRF) receptor antagonist, α-helical CRF, attenuated GCGL-suppressed food intake. It seems likely that CRF receptor is involved in the GCGL-induced anorexigenic pathway. All our findings suggest that GCGL functions as an anorexigenic peptide in the central nervous system of chicks.
Collapse
Affiliation(s)
- Kazuhisa Honda
- Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan.
| | - Takaoki Saneyasu
- Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| | - Takuya Yamaguchi
- Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| | | | - Koji Aoki
- Faculty of Agriculture, Kobe University, Kobe 657-8501, Japan
| | - Kiwako Nakanishi
- Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| | - Hiroshi Kamisoyama
- Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| |
Collapse
|
9
|
Pirone A, Ding BA, Giannessi E, Coli A, Stornelli MR, di Cossato MMF, Piano I, Lenzi C. Glucagon-like peptide 1 (GLP-1) in the gastrointestinal tract of the pheasant (Phasianus colchicus). Acta Histochem 2012; 114:535-9. [PMID: 22036174 DOI: 10.1016/j.acthis.2011.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 10/07/2011] [Accepted: 10/09/2011] [Indexed: 12/25/2022]
Abstract
The distribution of Glucagon-like peptide 1 (GLP-1) was investigated in the gastrointestinal tract of the pheasant using immunohistochemistry. GLP-1 immunoreactive cells were common in the small intestine, in the proventriculus and in the pancreas. Immunostained cells were not seen in the crop, in the gizzard and in the large intestine. Double labelling demonstrated that GLP-1 and pituitary adenylate cyclase-activating polypeptide (PACAP) were occasionally co-localized only in the duodenal villi. In contrast to what was previously described in the chicken and ostrich, we noted GLP-1 positive cells in the duodenum. These data were consistent with the presence of proglucagon mRNA in the chicken duodenum. Our findings indicate that GLP-1 might have an inhibitory effect on gastric and crop emptying and on acid secretion also in the pheasant. Moreover, the results of the present research regarding the initial region of the small intestine suggest a further direct mechanism of the GLP-1 release during the early digestion phase and an enhancement of its incretin role.
Collapse
|
10
|
Cariou B. Harnessing the incretin system beyond glucose control: potential cardiovascular benefits of GLP-1 receptor agonists in type 2 diabetes. DIABETES & METABOLISM 2012; 38:298-308. [PMID: 22672960 DOI: 10.1016/j.diabet.2012.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 04/14/2012] [Accepted: 04/14/2012] [Indexed: 12/25/2022]
Abstract
The management of type 2 diabetes continues to evolve as new data emerge. Although glycaemic control is still important, other risk factors--such as hypertension, dyslipidaemia and obesity--must also be addressed in order to reduce the long-term risks of cardiovascular complications and mortality. In this context, targeting the incretin system, and glucagon-like peptide-1 (GLP-1) in particular, has generated much interest. GLP-1 is released from the gut in response to food ingestion and plays a crucial role in glucose homeostasis. GLP-1 receptors are expressed in the heart and vasculature, prompting evaluation of their physiological role and pharmacological stimulation, both in healthy and disease states. These studies indicate that GLP-1 and GLP-1-based therapies appear to have direct, beneficial effects on the cardiovascular system, in addition to their glucose-lowering properties, such as modulation of blood pressure, endothelial function, and myocardial contractility. Intriguingly, some of these effects appear to be independent of GLP-1 receptor signalling. Data from clinical studies of the GLP-1 receptor agonists, exenatide and liraglutide on cardiovascular risk factors, in patients with type 2 diabetes are also promising and the results from prospective studies to assess cardiovascular outcomes are eagerly awaited.
Collapse
Affiliation(s)
- B Cariou
- Université de Nantes, CHU de Nantes, Hôpital Guillaume et René-Laennec, boulevard Jacques-Monod, Saint-Herblain, 44093 Nantes cedex 1, France.
| |
Collapse
|
11
|
Polakof S, Míguez JM, Soengas JL. Evidence for a gut-brain axis used by glucagon-like peptide-1 to elicit hyperglycaemia in fish. J Neuroendocrinol 2011; 23:508-18. [PMID: 21564347 DOI: 10.1111/j.1365-2826.2011.02137.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In mammals, glucagon-like peptide-1 (GLP-1) produces changes in glucose and energy homeostasis through a gut-pancreas-brain axis. In fish, the effects of GLP-1 are opposed to those described in other vertebrates, such as stimulation of hyperglycaemia and the lack of an effect of incretin. In the present study conducted in a teleost fish such as the rainbow trout, we present evidence of a gut-brain axis used by GLP-1 to exert its actions on glucose and energy homeostasis. We have assessed the effects of GLP-1 on glucose metabolism in the liver as well as the glucose-sensing potential in the hypothalamus and hindbrain. We confirm that peripheral GLP-1 administration elicits sustained hyperglycaemia, whereas, for the first time in a vertebrate species, we report that central GLP-1 treatment increases plasma glucose levels. We have observed (using capsaicin) that at least part of the action of GLP-1 on glucose homeostasis was mediated by vagal and splanchnic afferents. GLP-1 has a direct effect in parameters involved in glucose sensing in the hindbrain, whereas, in the hypothalamus, changes occurred indirectly through hyperglycaemia. Moreover, in the hindbrain, GLP-1 altered the expression of peptides involved in the control of food intake. We have elaborated a model for the actions of GLP-1 in fish in which this peptide uses a mammalian-like ancestral gut-brain axis to elicit the regulation of glucose homeostasis in different manner than the model described in mammals. Finally, it is worth noting that the hyperglycaemia induced by this peptide and the lack of incretin function could be related to the glucose intolerance observed in carnivorous teleost fish species such as the rainbow trout.
Collapse
Affiliation(s)
- S Polakof
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo, Spain.
| | | | | |
Collapse
|
12
|
Tachibana T, Matsuda K, Khan MSI, Ueda H, Cline MA. Feeding and drinking response following central administration of neuromedin S in chicks. Comp Biochem Physiol A Mol Integr Physiol 2010; 157:63-7. [PMID: 20451649 DOI: 10.1016/j.cbpa.2010.04.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 04/28/2010] [Accepted: 04/29/2010] [Indexed: 10/19/2022]
Abstract
Neuromedin S (NMS) is recognized as an anorexigenic peptide in the brain of mammals. In chicks (Gallus gallus), however, the effect of NMS has not been investigated. Therefore, the purpose of the present study was to investigate whether intracerebroventricular (ICV) injection of NMS affected feeding and drinking behavior in chicks. The injection of NMS (0.01-1 nmol) significantly decreased food intake under both ad libitum and food deprivation-induced feeding conditions. However, NMS did not affect water deprivation-induced drinking behavior. ICV injection of NMS stimulated voluntary locomotion and wing-flapping behavior. In addition, we found that those effects of NMS might be related to the hypothalamus-pituitary-adrenal axis because ICV injection of NMS stimulated corticosterone release. The present study suggests that central NMS functions an anorexigenic factor in chicks.
Collapse
Affiliation(s)
- Tetsuya Tachibana
- Department of Agrobiological Science, Faculty of Agriculture, Ehime University, Matsuyama 790-8566, Japan.
| | | | | | | | | |
Collapse
|
13
|
Richards MP, McMurtry JP. The avian proglucagon system. Gen Comp Endocrinol 2009; 163:39-46. [PMID: 18938167 DOI: 10.1016/j.ygcen.2008.09.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 09/04/2008] [Accepted: 09/25/2008] [Indexed: 10/21/2022]
Abstract
Understanding how the proglucagon system functions in maintaining glycemic control and energy balance in birds, as well as defining its specific roles in regulating metabolism, gastrointestinal tract function and food intake requires detailed knowledge of the components that comprise this system. These include proglucagon, a precursor protein from which glucagon and two glucagon-like peptide hormones (GLP-1 and GLP-2) are derived, and the membrane bound G-protein-coupled receptors that specifically bind glucagon, GLP-1 and GLP-2 to mediate their individual physiological actions. Another key feature of the proglucagon system that is important for regulating its activity in different tissues involves post-translational processing of the proglucagon precursor protein and the individual peptide hormones derived from it. Currently, there is limited information about the proglucagon system in birds with the majority of that coming from studies involving chickens. By summarizing what is currently known about the proglucagon system in birds, this review aims to provide useful background information for future investigations that will explore the nature and actions of this important hormonal system in different avian species.
Collapse
Affiliation(s)
- Mark P Richards
- United States Department of Agriculture, Agricultural Research Service, Animal and Natural Resources Institute, Beltsville Agricultural Research Center, Beltsville, MD 20705-2350, USA.
| | | |
Collapse
|
14
|
Richards MP, McMurtry JP. Expression of proglucagon and proglucagon-derived peptide hormone receptor genes in the chicken. Gen Comp Endocrinol 2008; 156:323-38. [PMID: 18299131 DOI: 10.1016/j.ygcen.2008.01.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 12/13/2007] [Accepted: 01/16/2008] [Indexed: 11/24/2022]
Abstract
To better understand how the proglucagon system functions in birds, we utilized a molecular cloning strategy to sequence and characterize the chicken proglucagon gene that encodes glucagon, glucagon-like peptide (GLP)-1 and GLP-2. This gene has seven exons and six introns with evidence for an additional (alternate) first exon and two promoter regions. We identified two distinct classes of proglucagon mRNA transcripts (PGA and PGB) produced by alternative splicing at their 3'-ends. These were co-expressed in all tissues examined with pancreas and proventriculus showing the highest levels of each. Although both mRNA classes contained coding sequence for glucagon and GLP-1, class A mRNA lacked that portion of the coding region (CDS) containing GLP-2; whereas, class B mRNA had a larger CDS that included GLP-2. Both classes of mRNA transcripts exhibited two variants, each with a different 5'-end arising from alternate promoter and alternate first exon usage. Fasting and refeeding had no effect on proglucagon mRNA expression despite significant changes in plasma glucagon levels. To investigate potential differences in proglucagon precursor processing among tissues, mRNA expression for two prohormone convertase (PC) genes was analyzed. PC2 mRNA was predominantly expressed in pancreas and proventriculus, whereas PC1/3 mRNA was more highly expressed in duodenum and brain. We also determined mRNA expression of the specific receptor genes for glucagon, GLP-1 and GLP-2 to help define major sites of hormone action. Glucagon receptor mRNA was most highly expressed in liver and abdominal fat, whereas GLP-1 and GLP-2 receptor genes were highly expressed in the gastrointestinal tract, brain, pancreas and abdominal fat. These results offer new insights into structure and function of the chicken proglucagon gene, processing of the precursor proteins produced from it and potential activity sites for proglucagon-derived peptide hormones mediated by their cognate receptors.
Collapse
Affiliation(s)
- Mark P Richards
- Animal Biosciences and Biotechnology Laboratory, USDA, ARS, Animal and Natural Resources Institute, Beltsville Agricultural Research Center, BARC-East, Beltsville, MD 20705-2350, USA.
| | | |
Collapse
|