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Chenxu Z, Lidan S, Guoqiang H, Binbin G, Ting W, Xiaoyi S, Qian L. Discovery of novel glucagon-like peptide 1/cholecystokinin 1 receptor dual agonists. Eur J Pharm Sci 2024; 199:106818. [PMID: 38801960 DOI: 10.1016/j.ejps.2024.106818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 05/05/2024] [Accepted: 05/25/2024] [Indexed: 05/29/2024]
Abstract
The combined use of gastrointestinal hormones for treating metabolic diseases is gaining increasing attention. The potential of developing novel dual agonists targeting both cholecystokinin 1 (CCK-1) receptor and glucagon-like peptide 1 (GLP-1) receptor to improve the treatment of type 2 diabetes and obesity have not been fully explored. In this investigation, we reported a series of novel GLP-1/CCK-1 receptor co-agonists constructed by linking the C-terminus of a GLP-1 receptor agonist (bullfrog GLP-1) to the N-terminus of a CCK-1 receptor selective agonist NN9056. In comprehensive in vitro assays, these co-agonists exhibited complete agonistic potency on GLP-1 and CCK-1 receptor. Remarkably, 1f displayed superior hypoglycemic and insulinotropic effects when compared to NN9056 and semaglutide. Evaluation in Kunming and diet-induced obesity (DIO) mice unveiled significant acute and enduring hypoglycemic effects of 1f. Administration of 1f to DIO mice resulted in substantial weight loss, normalized lipid metabolism, and enhanced glucose regulation. These preclinical observations strongly advocate for the therapeutic potential CCK-1 and GLP-1 pathways could be harnessed in a single fusion peptide, yielding a promising combination therapy strategy for treating metabolic disorders.
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Affiliation(s)
- Zhou Chenxu
- College of Medicine, Jiaxing University, Jiaxing 314001, PR China
| | - Sun Lidan
- College of Medicine, Jiaxing University, Jiaxing 314001, PR China; Taizhou Hospital, Zhejiang University, Taigzhou 317000, PR China.
| | - Hu Guoqiang
- Taizhou Hospital, Zhejiang University, Taigzhou 317000, PR China
| | - Gong Binbin
- College of Medicine, Jiaxing University, Jiaxing 314001, PR China; College of Pharmacy, Zhejiang University of Technology, Hangzhou 310000, PR China
| | - Wang Ting
- College of Medicine, Jiaxing University, Jiaxing 314001, PR China; College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, PR China
| | - Sun Xiaoyi
- School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou 221116, PR China
| | - Long Qian
- School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou 221116, PR China
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Yang Q, Zhou F, Tang X, Wang J, Feng H, Jiang W, Jin L, Jiang N, Yuan Y, Han J, Yan Z. Peptide-based long-acting co-agonists of GLP-1 and cholecystokinin 1 receptors as novel anti-diabesity agents. Eur J Med Chem 2022; 233:114214. [DOI: 10.1016/j.ejmech.2022.114214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 02/12/2022] [Accepted: 02/18/2022] [Indexed: 12/13/2022]
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Page AJ. Gastrointestinal Vagal Afferents and Food Intake: Relevance of Circadian Rhythms. Nutrients 2021; 13:nu13030844. [PMID: 33807524 PMCID: PMC7998414 DOI: 10.3390/nu13030844] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/25/2021] [Accepted: 03/03/2021] [Indexed: 01/20/2023] Open
Abstract
Gastrointestinal vagal afferents (VAs) play an important role in food intake regulation, providing the brain with information on the amount and nutrient composition of a meal. This is processed, eventually leading to meal termination. The response of gastric VAs, to food-related stimuli, is under circadian control and fluctuates depending on the time of day. These rhythms are highly correlated with meal size, with a nadir in VA sensitivity and increase in meal size during the dark phase and a peak in sensitivity and decrease in meal size during the light phase in mice. These rhythms are disrupted in diet-induced obesity and simulated shift work conditions and associated with disrupted food intake patterns. In diet-induced obesity the dampened responses during the light phase are not simply reversed by reverting back to a normal diet. However, time restricted feeding prevents loss of diurnal rhythms in VA signalling in high fat diet-fed mice and, therefore, provides a potential strategy to reset diurnal rhythms in VA signalling to a pre-obese phenotype. This review discusses the role of the circadian system in the regulation of gastrointestinal VA signals and the impact of factors, such as diet-induced obesity and shift work, on these rhythms.
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Affiliation(s)
- Amanda J. Page
- Adelaide Medical School, University of Adelaide, Adelaide, SA 5000, Australia; ; Tel.: +61-8-8128-4840
- Nutrition, Diabetes and Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institution (SAHMRI), Adelaide, SA 5000, Australia
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Page AJ, Kentish SJ. Plasticity of gastrointestinal vagal afferent satiety signals. Neurogastroenterol Motil 2017; 29. [PMID: 27781333 DOI: 10.1111/nmo.12973] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 09/19/2016] [Indexed: 12/21/2022]
Abstract
The vagal link between the gastrointestinal tract and the central nervous system (CNS) has numerous vital functions for maintaining homeostasis. The regulation of energy balance is one which is attracting more and more attention due to the potential for exploiting peripheral hormonal targets as treatments for conditions such as obesity. While physiologically, this system is well tuned and demonstrated to be effective in the regulation of both local function and promoting/terminating food intake the neural connection represents a susceptible pathway for disruption in various disease states. Numerous studies have revealed that obesity in particularly is associated with an array of modifications in vagal afferent function from changes in expression of signaling molecules to altered activation mechanics. In general, these changes in vagal afferent function in obesity further promote food intake instead of the more desirable reduction in food intake. It is essential to gain a comprehensive understanding of the mechanisms responsible for these detrimental effects before we can establish more effective pharmacotherapies or lifestyle strategies for the treatment of obesity and the maintenance of weight loss.
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Affiliation(s)
- A J Page
- Centre for Nutrition and Gastrointestinal Disease, Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia.,Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.,Department of Gastroenterology and Hepatology, Royal Adelaide Hospital, Adelaide, SA, Australia
| | - S J Kentish
- Centre for Nutrition and Gastrointestinal Disease, Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia.,Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.,School of Medicine, University of Queensland, St Lucia, QLD, Australia
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Shaban H, O’Connor R, Ovsepian SV, Dinan TG, Cryan JF, Schellekens H. Electrophysiological approaches to unravel the neurobiological basis of appetite and satiety: use of the multielectrode array as a screening strategy. Drug Discov Today 2017; 22:31-42. [DOI: 10.1016/j.drudis.2016.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/03/2016] [Accepted: 09/06/2016] [Indexed: 01/10/2023]
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Seow KM, Lee JL, Doong ML, Huang SW, Hwang JL, Huang WJ, Chang FY, Ho LT, Juan CC. Human chorionic gonadotropin regulates gastric emptying in ovariectomized rats. J Endocrinol 2013. [PMID: 23197744 DOI: 10.1530/joe-12-0421] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Prolongation of gastrointestinal transit resulting in nausea and vomiting in pregnancy (NVP) is the most common phenomenon during the first trimester of pregnancy. Increased human chorionic gonadotropin (hCG) concentration during the first trimester is the most likely cause of NVP. The aim of this study was to investigate the effect of hCG on gastrointestinal transit and plasma concentrations of cholecystokinin (CCK) in ovariectomized (Ovx) rats. I.p. injection of hCG was used to evaluate the dose effect of hCG on gastrointestinal transit in Ovx rats. The CCK antagonist lorglumide was used to clarify the role of CCK in regulating gastrointestinal transit. Gastrointestinal transit was assessed 15 min after intragastric gavage of a mixture of 10% charcoal and Na(2)(51)CrO(4) (0.5 μCi/ml). After i.p. administration of hCG, gastric emptying was inhibited in Ovx rats, but intestinal transit was not affected. Plasma CCK concentrations were increased in a dose-dependent manner after hCG treatment, and gastric emptying showed a significant negative correlation with CCK concentrations (P=0.01, r(2)=-0.5104). Peripheral administration (i.p.) of lorglumide, a selective CCK(1) receptor antagonist, attenuated the hCG-induced inhibition of gastric emptying in Ovx rats, whereas central administration via the i.c.v. route did not. hCG treatment of Ovx rats inhibits gastric emptying in a dose-dependent manner via a peripheral mechanism of CCK hypersecretion and activation of CCK(1) receptors.
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Affiliation(s)
- Kok-Min Seow
- Department of Obstetrics and Gynecology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
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Takenaka Y, Shimano T, Mori T, Hou IC, Ohinata K, Yoshikawa M. Enterostatin reduces serum cholesterol levels by way of a CCK(1) receptor-dependent mechanism. Peptides 2008; 29:2175-8. [PMID: 18824202 DOI: 10.1016/j.peptides.2008.08.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Revised: 08/29/2008] [Accepted: 08/29/2008] [Indexed: 11/30/2022]
Abstract
Enterostatin (APGPR), an anorectic pentapeptide derived from the amino terminus of procolipase, significantly reduced serum cholesterol levels after oral administration at a dose of 100 mg/kg for 3 days in mice fed a high-cholesterol-cholic acid diet. The hypocholesterolemic effect of APGPR was inhibited by pretreatment with lorglumide, an antagonist for cholecystokinin 1 (CCK(1)) receptor, even though APGPR does not have any affinity for CCK(1) receptors. Similarly, the hypocholesterolemic activity of VPDPR, an APGPR analogue, was blocked by lorglumide. These results suggest that the hypocholesterolemic effects of APGPR and VPDPR are mediated by a CCK(1) receptor-dependent mechanism.
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Affiliation(s)
- Yasuyuki Takenaka
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan
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Takenaka Y, Shimano T, Yamada Y, Yoshida M, Ohinata K, Yoshikawa M. Enterostatin (APGPR) suppresses the analgesic activity of morphine by a CCK-dependent mechanism. Peptides 2008; 29:559-63. [PMID: 18304696 DOI: 10.1016/j.peptides.2007.12.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 12/21/2007] [Accepted: 12/21/2007] [Indexed: 10/22/2022]
Abstract
Enterostatin (APGPR) found in the gastrointestinal tract and brain is an anorectic pentapeptide. We found that APGPR inhibited morphine-induced analgesia after intracerebroventricular administration in mice at a dose of 10nmol/mouse. The anti-analgesic effect of APGPR was inhibited by pretreatment with lorglumide and LY225910, antagonists for cholecystokinin 1 (CCK1) and cholecystokinin 2 (CCK2) receptors, respectively. The anti-analgesic effect of APGPR may be mediated by CCK release, since APGPR does not have affinity for CCK receptors.
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Affiliation(s)
- Yasuyuki Takenaka
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
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Ohinata K, Sonoda S, Shimano T, Yoshikawa M. Enterostatin (APGPR) enhances memory consolidation in mice. Peptides 2007; 28:719-21. [PMID: 17175068 DOI: 10.1016/j.peptides.2006.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 11/06/2006] [Accepted: 11/07/2006] [Indexed: 11/23/2022]
Abstract
Enterostatin (APGPR) is a pentapeptide released from its precursor protein, procolipase. We found for the first time that enterostatin has memory-enhancing activity. Enterostatin enhanced memory consolidation after central or oral administration at a dose of 10 nmol/mouse or 300 mg/kg, respectively, in a step-through type passive avoidance test in mice. The memory-enhancing activity of enterostatin was inhibited by pretreatment with lorglumide, an antagonist for cholecystokinin 1 (CCK1) receptor. However, enterostatin had no affinity for CCK receptors. These results suggest that enterostatin improves memory retention through CCK release.
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Affiliation(s)
- Kousaku Ohinata
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan
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12
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Lin L, Park M, York DA. Enterostatin inhibition of dietary fat intake is modulated through the melanocortin system. Peptides 2007; 28:643-9. [PMID: 17113194 PMCID: PMC1847607 DOI: 10.1016/j.peptides.2006.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 10/04/2006] [Accepted: 10/05/2006] [Indexed: 10/23/2022]
Abstract
Enterostatin injected into the amygdala selectively reduces dietary fat intake by an action that involves a serotonergic component in the paraventricular nucleus. We have investigated the role of melanocortin signaling in the response to enterostatin by studies in melanocortin 4 receptor (MC4R) knock out mice and by the use of the MC4R and MC3R antagonist SHU9119, and by neurochemical phenotyping of enterostatin activated cells. We also determined the effect of enterostatin in vivo on the expression of AgRP in the hypothalamus and amygdala of rats and in culture on a GT1-7 neuronal cell line. Enterostatin had no effect on food intake in MC4R knock out mice. SHU9119 i.c.v. blocked the feeding response to amygdala enterostatin in rats. Amygdala enterostatin induced fos activation in alpha-melanocyte stimulating hormone (alpha-MSH) neurons in the arcuate nucleus. Enterostatin also reduced the expression of AgRP in the hypothalamus and amygdala and in GT1-7 cells. These data suggest enterostatin inhibits dietary fat intake through a melanocortin signaling pathway.
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MESH Headings
- Agouti-Related Protein
- Amygdala/drug effects
- Amygdala/physiology
- Animals
- Arcuate Nucleus of Hypothalamus/drug effects
- Arcuate Nucleus of Hypothalamus/physiology
- Base Sequence
- Cell Line
- Colipases/pharmacology
- DNA Primers/genetics
- Dietary Fats/administration & dosage
- Eating/drug effects
- Eating/physiology
- Enzyme Precursors
- Female
- Gene Expression/drug effects
- Hypothalamus/drug effects
- Hypothalamus/physiology
- Intercellular Signaling Peptides and Proteins/genetics
- Intercellular Signaling Peptides and Proteins/physiology
- Melanocyte-Stimulating Hormones/pharmacology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Pro-Opiomelanocortin/genetics
- Protein Precursors/pharmacology
- Receptor, Melanocortin, Type 3/antagonists & inhibitors
- Receptor, Melanocortin, Type 3/physiology
- Receptor, Melanocortin, Type 4/antagonists & inhibitors
- Receptor, Melanocortin, Type 4/deficiency
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/physiology
- Signal Transduction/drug effects
- alpha-MSH/metabolism
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Affiliation(s)
- Ling Lin
- Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808, USA and
| | - MieJung Park
- Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808, USA and
- Center for Advanced Nutrition, Utah State University, 4715 Old Main Hill, Logan, UT 84322, USA
| | - David A. York
- Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808, USA and
- Center for Advanced Nutrition, Utah State University, 4715 Old Main Hill, Logan, UT 84322, USA
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13
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Marczak ED, Ohinata K, Lipkowski AW, Yoshikawa M. Arg-Ile-Tyr (RIY) derived from rapeseed protein decreases food intake and gastric emptying after oral administration in mice. Peptides 2006; 27:2065-8. [PMID: 16647789 DOI: 10.1016/j.peptides.2006.03.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2006] [Revised: 03/16/2006] [Accepted: 03/16/2006] [Indexed: 11/26/2022]
Abstract
We previously reported that a bioactive tripeptide Arg-Ile-Tyr (RIY), which has been isolated as an inhibitor for angiotensin I-converting enzyme from the subtilisin digest of rapeseed protein, decreased blood pressure. In this study, we also found that RIY dose-dependently decreased food intake at a dose of 150 mg/kg after oral administration in fasted ddY male mice. The anorexigenic action of RIY was blocked by a cholecystokinin-1 CCK1 receptor antagonist, lorglumide. RIY also decreased the gastric emptying rate at a dose of 150 mg/kg and the RIY-induced delay of gastric emptying was blocked by lorglumide. However, RIY had no affinity for CCK1 receptor. Taken together, RIY decreased food intake and gastric emptying by stimulating CCK release.
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Affiliation(s)
- Ewa D Marczak
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan
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York DA, Lin L, Thomas SR, Braymer HD, Park M. Procolipase gene expression in the rat brain: source of endogenous enterostatin production in the brain. Brain Res 2006; 1087:52-9. [PMID: 16624258 DOI: 10.1016/j.brainres.2006.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Revised: 02/22/2006] [Accepted: 03/07/2006] [Indexed: 11/29/2022]
Abstract
Enterostatin is a pentapeptide released from its precursor protein procolipase, which is synthesized in the exocrine pancreas and gastric mucosa. As central injection of enterostatin has potent effects on feeding, we hypothesized that the procolipase may also be expressed in the brain. We confirmed the presence of preprocolipase gene expression in amygdala by reverse transcription-polymerase chain reaction and Northern blot analysis and of protein expression by Western blots. Immunohistochemical analysis using antibodies for procolipase and enterostatin identified their immunoreactivity (IR) in rat brain. Procolipase IR was present in the cytoplasm of paraventricular, amygdala, and the dorsal thalamus nucleus. Enterostatin IR was evident in the fibers of the dorsal thalamus and arcuate nucleus. In vivo injection of enterostatin antibody into rat amygdala increased food intake. These data suggest that procolipase and enterostatin are synthesized within specific regions of the brain that function in the regulation of food intake centrally.
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Affiliation(s)
- David A York
- Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA.
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Lin L, Park M, Hulver M, York DA. Different metabolic responses to central and peripheral injection of enterostatin. Am J Physiol Regul Integr Comp Physiol 2006; 290:R909-15. [PMID: 16339388 PMCID: PMC2526557 DOI: 10.1152/ajpregu.00045.2005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Enterostatin, a pentapeptide cleaved from procolipase, suppresses fat intake after peripheral and central administration. Chronic treatment of rats with enterostatin decreases body weight and body fat. The effect was greater than could be accounted by the reduction in food intake alone. Hence, we have investigated the effect of enterostatin on energy metabolism. Male Sprague-Dawley rats adapted to a high-fat diet were implanted with lateral cerebral ventricular or amygdala cannulas. The metabolic effects were determined by indirect calorimetry. After habituation to the test cages, fasted rats were injected with either saline vehicle or enterostatin given either intraperitoneally (100 nmol) or intracerebroventricularly (1 nmol) or into specific brain regions [amygdala (0.01 nmol) or paraventricular nucleus (PVN) (0.1 nmol)]. Respiratory quotient (RQ) and energy expenditure were monitored over 2 h. Intraperitoneal enterostatin reduced RQ (saline: 0.81 +/- 0.02 vs. enterostatin: 0.76 +/- 0.01) and increased energy expenditure by 44%. Intracerebroventricular enterostatin increased the energy expenditure without any effects on RQ, whereas PVN enterostatin increased metabolic rate, while preventing the increase in RQ observed in the control animals. In contrast, neither RQ nor energy expenditure was altered after enterostatin was injected into the amygdala. Enterostatin activated AMP-activated protein kinase in primary cultures of human myocytes in a dose- and time-dependent manner and increased the rate of fatty acid beta-oxidation. These findings suggest that enterostatin regulates energy expenditure and substrate partitioning through both peripheral and central effects.
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Affiliation(s)
- Ling Lin
- Pennington Biomedical Research Center, 6400 Perkins Rd., Baton Rouge, LA 70808, USA
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Affiliation(s)
- W A Cupples
- Centre for Biomedical Research, Department of Biology, University of Victoria, PO Box 3020, STN CSC Victoria, British Columbia, Canada V8W 3N5.
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Berger K, Winzell MS, Mei J, Erlanson-Albertsson C. Enterostatin and its target mechanisms during regulation of fat intake. Physiol Behav 2005; 83:623-30. [PMID: 15621068 DOI: 10.1016/j.physbeh.2004.08.040] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Accepted: 08/02/2004] [Indexed: 10/26/2022]
Abstract
A high-fat diet easily promotes hyperphagia giving an impression of an uncontrolled process. Fat digestion itself however provides control of fat intake through the digestion itself, carried out by pancreatic lipase and its protein cofactor colipase, and through enterostatin, a peptide released from procolipase during fat digestion. Procolipase (-/-) knockout mice have a severely reduced fat digestion and fat uptake, pointing to a major role of the digestive process itself. With a normal fat digestion, enterostatin basically restricts fat intake by preventing the overconsumption of fat. The mechanism for enterostatin might be an inhibition of a mu-opioid-mediated pathway, demonstrated through binding studies on SK-N-MC-cells and crude brain membranes. Another target protein of enterostatin is the beta-subunit of F1F0-ATPase, displaying a distinct binding of enterostatin, established through an aqueous two-phase partition system. The binding of enterostatin to F1-ATPase was partially displaced by beta-casomorphin, a peptide stimulating fat intake and acting competitively to enterostatin. We frame a hypothesis that regulation of fat intake through enterostatin contains a reward component, which is an F1-ATPase-mediated pathway, possibly complemented with an opioidergic pathway.
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Affiliation(s)
- Karin Berger
- Department of Cell and Molecular Biology, Biomedical Center BMC, C11, Lund University, SE-221 84 Lund, Sweden
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Thorens B, Larsen PJ. Gut-derived signaling molecules and vagal afferents in the control of glucose and energy homeostasis. Curr Opin Clin Nutr Metab Care 2004; 7:471-8. [PMID: 15192452 DOI: 10.1097/01.mco.0000134368.91900.84] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE OF REVIEW The control of glucose and energy homeostasis, including feeding behaviour, is tightly regulated by gut-derived peptidic and nonpeptidic endocrine mediators, autonomic nervous signals, as well as nutrients such as glucose. We will review recent findings on the role of the gastrointestinal tract innervation and of portal vein glucose sensors; we will review selected data on the action of gastrointestinally released hormones. RECENT FINDINGS The involvement of mechanosensory vagal afferents in postprandial meal termination has been clarified using mouse models with selective impairments of genes required for development of mechanosensory fibres. These activate central glucogen-like peptide-1/glucogen-like peptide-2 containing ascending pathways linking the visceroceptive brainstem neurons to hypothalamic nuclei. Mucosal terminals comprise the chemosensory vagal afferents responsive to postprandially released gastrointestinal hormones. The mechanism by which the hepatoportal glucose sensor stimulates glucose utilization by muscles was demonstrated, using genetically modified mice, to be insulin-independent but to require GLUT4 and AMP-kinase. This sensor is a key site of glucogen-like peptide-1 action and plays a critical role in triggering first phase insulin secretion. PeptideYY and ghrelin target intracerebral receptors as they are bidirectionally transported across the blood brain barrier. The anorectic functions of peripherally released peptideYY may however be mediated both via vagal afferents and intracerebral Y2 receptors in the brainstem and arcuate nucleus. SUMMARY These recent findings demonstrate that the use of improved anatomical and physiological techniques and animal models with targeted gene modifications lead to an improved understanding of the complex role of gastrointestinal signals in the control of energy homeostasis.
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