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Azuma M, Konno N, Sakata I, Koshimizu TA, Kaiya H. Molecular characterization and distribution of motilin and motilin receptor in the Japanese medaka Oryzias latipes. Cell Tissue Res 2024; 397:61-76. [PMID: 38727755 DOI: 10.1007/s00441-024-03896-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 04/30/2024] [Indexed: 07/09/2024]
Abstract
Motilin (MLN) is a peptide hormone originally isolated from the mucosa of the porcine intestine. Its orthologs have been identified in various vertebrates. Although MLN regulates gastrointestinal motility in tetrapods from amphibians to mammals, recent studies indicate that MLN is not involved in the regulation of isolated intestinal motility in zebrafish, at least in vitro. To determine the unknown function of MLN in teleosts, we examined the expression of MLN and the MLN receptor (MLNR) at the cellular level in Japanese medaka (Oryzias latipes). Quantitative PCR revealed that mln mRNA was limitedly expressed in the gut, whereas mlnr mRNA was not detected in the gut but was expressed in the brain and kidney. By in situ hybridization and immunohistochemistry, mlnr mRNA was detected in the dopaminergic neurons of the area postrema in the brain and the noradrenaline-producing cells in the interrenal gland of the kidney. Furthermore, we observed efferent projections of mlnr-expressing dopaminergic neurons in the lobus vagi (XL) and nucleus motorius nervi vagi (NXm) of the medulla oblongata by establishing a transgenic medaka expressing the enhanced green fluorescence protein driven by the mlnr promoter. The expression of dopamine receptor mRNAs in the XL and cholinergic neurons in NXm was confirmed by in situ hybridization. These results indicate novel sites of MLN activity other than the gastrointestinal tract. MLN may exert central and peripheral actions through the regulation of catecholamine release in medaka.
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Affiliation(s)
- Morio Azuma
- Division of Molecular Pharmacology, Department of Pharmacology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, Japan.
| | - Norifumi Konno
- Department of Biological Science, Graduate School of Science and Engineering, University of Toyama, Gofuku, Toyama, 3190, Japan
| | - Ichiro Sakata
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimookubo, Saitama, Japan
| | - Taka-Aki Koshimizu
- Division of Molecular Pharmacology, Department of Pharmacology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, Japan
| | - Hiroyuki Kaiya
- Department of Biological Science, Graduate School of Science and Engineering, University of Toyama, Gofuku, Toyama, 3190, Japan
- Division of Drug Discovery, Grandsoul Research Institute for Immunology, Inc. 8-1 Utano-Matsui, Uda, Nara, Japan
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Tang N, Li Y, Li Y, Xu S, Wang M, Wang B, Liu Y, Zhang S, Wu H, Zhang X, Zhou B, Li Z. Motilin, a Novel Orexigenic Factor, Involved in Feeding Regulation in Yangtze Sturgeon ( Acipenser dabryanus). Biomolecules 2024; 14:433. [PMID: 38672450 PMCID: PMC11048545 DOI: 10.3390/biom14040433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/19/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
Motilin is a gastrointestinal hormone that is mainly produced in the duodenum of mammals, and it is responsible for regulating appetite. However, the role and expression of motilin are poorly understood during starvation and the weaning stage, which is of great importance in the seeding cultivation of fish. In this study, the sequences of Yangtze sturgeon (Acipenser dabryanus Motilin (AdMotilin)) motilin receptor (AdMotilinR) were cloned and characterized. The results of tissue expression showed that by contrast with mammals, AdMotilin mRNA was richly expressed in the brain, whereas AdMotilinR was highly expressed in the stomach, duodenum, and brain. Weaning from a natural diet of T. Limnodrilus to commercial feed significantly promoted the expression of AdMotilin in the brain during the period from day 1 to day 10, and after re-feeding with T. Limnodrilus the change in expression of AdMotilin was partially reversed. Similarly, it was revealed that fasting increased the expression of AdMotilin in the brain (3 h, 6 h) and duodenum (3 h), and the expression of AdMotilinR in the brain (1 h) in a time-dependent manner. Furthermore, it was observed that peripheral injection of motilin-NH2 increased food intake and the filling index of the digestive tract in the Yangtze sturgeon, which was accompanied by the changes of AdMotilinR and appetite factors expression in the brain (POMC, CART, AGRP, NPY and CCK) and stomach (CCK). These results indicate that motilin acts as an indicator of nutritional status, and also serves as a novel orexigenic factor that stimulates food intake in Acipenser dabryanus. This study lays a strong foundation for the application of motilin as a biomarker in the estimation of hunger in juvenile Acipenser dabryanu during the weaning phase, and enhances the understanding of the role of motilin as a novel regulator of feeding in fish.
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Affiliation(s)
- Ni Tang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (N.T.); (Y.L.); (Y.L.); (S.X.); (M.W.); (Y.L.); (S.Z.); (H.W.); (X.Z.)
| | - Ya Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (N.T.); (Y.L.); (Y.L.); (S.X.); (M.W.); (Y.L.); (S.Z.); (H.W.); (X.Z.)
| | - Yingzi Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (N.T.); (Y.L.); (Y.L.); (S.X.); (M.W.); (Y.L.); (S.Z.); (H.W.); (X.Z.)
| | - Shaoqi Xu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (N.T.); (Y.L.); (Y.L.); (S.X.); (M.W.); (Y.L.); (S.Z.); (H.W.); (X.Z.)
| | - Mei Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (N.T.); (Y.L.); (Y.L.); (S.X.); (M.W.); (Y.L.); (S.Z.); (H.W.); (X.Z.)
| | - Bin Wang
- Fisheries Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China;
| | - Yanling Liu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (N.T.); (Y.L.); (Y.L.); (S.X.); (M.W.); (Y.L.); (S.Z.); (H.W.); (X.Z.)
| | - Shupeng Zhang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (N.T.); (Y.L.); (Y.L.); (S.X.); (M.W.); (Y.L.); (S.Z.); (H.W.); (X.Z.)
| | - Hongwei Wu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (N.T.); (Y.L.); (Y.L.); (S.X.); (M.W.); (Y.L.); (S.Z.); (H.W.); (X.Z.)
| | - Xin Zhang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (N.T.); (Y.L.); (Y.L.); (S.X.); (M.W.); (Y.L.); (S.Z.); (H.W.); (X.Z.)
| | - Bo Zhou
- Fisheries Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China;
| | - Zhiqiong Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (N.T.); (Y.L.); (Y.L.); (S.X.); (M.W.); (Y.L.); (S.Z.); (H.W.); (X.Z.)
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Sadig RR, Allende A, Hall G, Tran D, Madigan MC, Watson SL, Ooi KGJ. Motilin Receptor Expression Found in the Human Main and Accessory Lacrimal Glands. Ocul Immunol Inflamm 2022; 30:1553-1558. [PMID: 33974477 DOI: 10.1080/09273948.2021.1903937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/22/2021] [Accepted: 03/09/2021] [Indexed: 12/16/2022]
Abstract
INTRODUCTION In this study, we investigated the presence of motilin receptors (MR) in adnexal tissue including the human main lacrimal gland. METHOD 17 adnexal human specimens comprising of 11 isolated human main lacrimal gland specimens, four full-thickness human eyelid excisions and two exenterations containing full-thickness eyelid and portions of the main lacrimal gland were immunolabelled with a rabbit polyclonal human MR antibody. RESULTS Our results demonstrated that all main lacrimal gland specimens (13/13, 100%) were positive for MR expression with a predominance (10/13 (77%) of grade 1+ punctate distribution. Motilin receptors were not found in eccrine glands, cutaneous sebaceous glands, glands of Zeis or glands of Moll (0/6, 0%). We also confirmed MR expression in the accessory lacrimal gland tissue. CONCLUSION In summary, we discovered the MR receptor in the lacrimal and accessory lacrimal gland - the significance of which, in the lacrimal gland, remains unclear - but motilin may play a role in the muscarinic control of aqueous tear secretion.
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Affiliation(s)
- Richard R Sadig
- Save Sight Institute, University of Sydney, Sydney, Australia
| | - Alexandra Allende
- Department of Anatomical Pathology, Douglass Hanly Moir Pathology Park Lab, Sydney, Australia
| | - Geoffrey Hall
- Department of Anatomical Pathology, Douglass Hanly Moir Pathology Park Lab, Sydney, Australia
| | - Dinh Tran
- Department of Anatomical Pathology, Douglass Hanly Moir Pathology Park Lab, Sydney, Australia
| | | | | | - Kenneth G-J Ooi
- Save Sight Institute, University of Sydney, Sydney, Australia
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Kitazawa T, Kaiya H. Motilin Comparative Study: Structure, Distribution, Receptors, and Gastrointestinal Motility. Front Endocrinol (Lausanne) 2021; 12:700884. [PMID: 34497583 PMCID: PMC8419268 DOI: 10.3389/fendo.2021.700884] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/16/2021] [Indexed: 12/26/2022] Open
Abstract
Motilin, produced in endocrine cells in the mucosa of the upper intestine, is an important regulator of gastrointestinal (GI) motility and mediates the phase III of interdigestive migrating motor complex (MMC) in the stomach of humans, dogs and house musk shrews through the specific motilin receptor (MLN-R). Motilin-induced MMC contributes to the maintenance of normal GI functions and transmits a hunger signal from the stomach to the brain. Motilin has been identified in various mammals, but the physiological roles of motilin in regulating GI motility in these mammals are well not understood due to inconsistencies between studies conducted on different species using a range of experimental conditions. Motilin orthologs have been identified in non-mammalian vertebrates, and the sequence of avian motilin is relatively close to that of mammals, but reptile, amphibian and fish motilins show distinctive different sequences. The MLN-R has also been identified in mammals and non-mammalian vertebrates, and can be divided into two main groups: mammal/bird/reptile/amphibian clade and fish clade. Almost 50 years have passed since discovery of motilin, here we reviewed the structure, distribution, receptor and the GI motility regulatory function of motilin in vertebrates from fish to mammals.
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Affiliation(s)
- Takio Kitazawa
- Comparative Animal Pharmacology, Department of Veterinary Science, Rakuno Gakuen University, Ebetsu, Japan
| | - Hiroyuki Kaiya
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
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Singaram K, Gold-Smith FD, Petrov MS. Motilin: a panoply of communications between the gut, brain, and pancreas. Expert Rev Gastroenterol Hepatol 2020; 14:103-111. [PMID: 31996050 DOI: 10.1080/17474124.2020.1718492] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Introduction: Motilin was first alluded to nearly a century ago. But it remains a rather abstruse peptide, in the shadow of its younger but more lucid 'cousin' ghrelin.Areas covered: The review aimed to bring to the fore multifarious aspects of motilin research with a view to aiding prioritization of future studies on this gastrointestinal peptide.Expert opinion: Growing evidence indicates that rodents (mice, rats, guinea pigs) do not have functional motilin system and, hence, studies in these species are likely to have a minimal translational impact. Both the active peptide and motilin receptor were initially localized to the upper gastrointestinal tract only but more recently - also to the brain (in both humans and other mammals with functional motilin system). Motilin is now indisputably implicated in interdigestive contractile activity of the gastrointestinal tract (in particular, gastric phase III of the migrating motor complex). Beyond this role, evidence is building that there is a cross-talk between motilin system and the brain-pancreas axis, suggesting that motilin exerts not only contractile but also orexigenic and insulin secretagogue actions.
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Affiliation(s)
| | | | - Maxim S Petrov
- School of Medicine, University of Auckland, Auckland, New Zealand
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Kanoski SE, Grill HJ. Hippocampus Contributions to Food Intake Control: Mnemonic, Neuroanatomical, and Endocrine Mechanisms. Biol Psychiatry 2017; 81:748-756. [PMID: 26555354 PMCID: PMC4809793 DOI: 10.1016/j.biopsych.2015.09.011] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/22/2015] [Accepted: 09/21/2015] [Indexed: 10/23/2022]
Abstract
Food intake is a complex behavior that can occur or cease to occur for a multitude of reasons. Decisions about where, when, what, and how much to eat are not merely reflexive responses to food-relevant stimuli or to changes in energy status. Rather, feeding behavior is modulated by various contextual factors and by previous experiences. The data reviewed here support the perspective that neurons in multiple hippocampal subregions constitute an important neural substrate linking the external context, the internal context, and mnemonic and cognitive information to control both appetitive and ingestive behavior. Feeding behavior is heavily influenced by hippocampal-dependent mnemonic functions, including episodic meal-related memories and conditional learned associations between food-related stimuli and postingestive consequences. These mnemonic processes are undoubtedly influenced by both external and internal factors relating to food availability, location, and physiological energy status. The afferent and efferent neuroanatomical connectivity of the subregions of the hippocampus is reviewed with regard to the integration of visuospatial and olfactory sensory information (the external context) with endocrine and gastrointestinal interoceptive stimuli (the internal context). Also discussed are recent findings demonstrating that peripherally derived endocrine signals act on receptors in hippocampal neurons to reduce (leptin, glucagon-like peptide-1) or increase (ghrelin) food intake and learned food reward-driven responding, thereby highlighting endocrine and neuropeptidergic signaling in hippocampal neurons as a novel substrate of importance in the higher-order regulation of feeding behavior.
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Affiliation(s)
- Scott E. Kanoski
- Department of Biological Sciences, University of Southern California
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Deloose E, Vos R, Janssen P, Van den Bergh O, Van Oudenhove L, Depoortere I, Tack J. The motilin receptor agonist erythromycin stimulates hunger and food intake through a cholinergic pathway. Am J Clin Nutr 2016; 103:730-7. [PMID: 26817505 DOI: 10.3945/ajcn.115.113456] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 12/16/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Motilin-induced phase III contractions have been identified as a hunger signal. These phase III contractions occur as part of the migrating motor complex (MMC), a contractility pattern of the gastrointestinal tract during fasting. The mechanism involved in this association between subjective hunger feelings and gastrointestinal motility during the MMC is largely unknown, however, as is its ability to stimulate food intake. OBJECTIVES We sought to 1) investigate the occurrence of hunger peaks and their relation to phase III contractions, 2) evaluate whether this relation was cholinergically driven, and 3) assess the ability of the motilin receptor agonist erythromycin to induce food intake. DESIGN An algorithm was developed to detect hunger peaks. The association with phase III contractions was studied in 14 healthy volunteers [50% men; mean ± SEM age: 25 ± 2 y; mean ± SEM body mass index (BMI; in kg/m(2)): 23 ± 1]. The impact of pharmacologically induced phase III contractions on the occurrence of hunger peaks and the involvement of a cholinergic pathway were assessed in 14 healthy volunteers (43% men; age: 29 ± 3 y; BMI: 23 ± 1). Last, the effect of erythromycin administration on food intake was examined in 15 healthy volunteers (40% men; age: 28 ± 3 y; BMI: 22 ± 1). RESULTS The occurrence of hunger peaks and their significant association with phase III contractions was confirmed (P < 0.0001). Pharmacologically induced phase III contractions were also significantly associated with hunger peaks (P < 0.05), and this association involved a cholinergic pathway. Administering erythromycin significantly stimulated food intake compared with placebo (53% ± 13% compared with 10% ± 5%; P < 0.05). CONCLUSIONS Motilin-induced phase III contractions induced hunger feelings through a cholinergic pathway. Moreover, erythromycin stimulated food intake, suggesting a physiologic role of motilin as an orexigenic signal from the gastrointestinal tract. This trial was registered at www.clinicaltrials.gov as NCT02633579.
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Affiliation(s)
- Eveline Deloose
- Translational Research Centre for Gastrointestinal Disorders (TARGID) and
| | - Rita Vos
- Translational Research Centre for Gastrointestinal Disorders (TARGID) and
| | - Pieter Janssen
- Translational Research Centre for Gastrointestinal Disorders (TARGID) and
| | - Omer Van den Bergh
- Research Group on Health Psychology, Department of Psychology, Catholic University of Leuven, Leuven, Belgium
| | | | - Inge Depoortere
- Translational Research Centre for Gastrointestinal Disorders (TARGID) and
| | - Jan Tack
- Translational Research Centre for Gastrointestinal Disorders (TARGID) and
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Lu Y, Zhong F, Wang X, Li H, Zhu Z, Kong X, Zhao J, Wu Q. Mechanism of motilin-mediated inhibition on voltage-dependent potassium currents in hippocampal neurons. Neuroscience 2014; 284:374-380. [PMID: 25168724 DOI: 10.1016/j.neuroscience.2014.08.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 07/11/2014] [Accepted: 08/11/2014] [Indexed: 01/30/2023]
Abstract
OBJECTIVE The effects of motilin on voltage-dependent K+ currents in hippocampal neurons with the addition of L-arginine (L-AA), D-arginine (D-AA) and N-nitro-L-arginine methyl ester (L-NAME) were investigated in this study. METHODS Mice (1-3 days old) were randomly assigned to different groups according to the addition of motilin, L-AA, D-AA, and L-NAME. The K+ current signals were detected by the whole-cell patch-clamp technique. RESULTS Compared with the control group, the transient outward voltage-dependent K+ current was significantly inhibited by motilin added with L-AA. In contrast, the addition of motilin and L-NAME significantly increased the K+ current, while no significant change was detected by the addition of motilin accompanied with D-AA. CONCLUSION The inhibiting effects of motilin on the voltage-dependent K+ current in hippocampal neurons indicate that motilin acts as a regulatory factor for the nitric oxide pathway.
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Affiliation(s)
- Y Lu
- Department of Neonatology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shanxi province 710061, China; Department of Physiology, Heze Medical College, Heze, Shandong Province, China.
| | - F Zhong
- Department of Stomatology, Medical College of Qingdao University, Qingdao, Shandong Province 266003, China.
| | - X Wang
- Department of Physiology, Heze Medical College, Heze, Shandong Province, China.
| | - H Li
- Department of Neonatology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shanxi province 710061, China.
| | - Z Zhu
- Department of Neonatology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shanxi province 710061, China; Shaanxi Province Biomedicine Key Laboratory, College of Life Sciences, Northwest University, Xi'an, Shanxi province, China.
| | - X Kong
- Department of Physiology, Heze Medical College, Heze, Shandong Province, China.
| | - J Zhao
- Department of Physiology, Heze Medical College, Heze, Shandong Province, China.
| | - Q Wu
- Department of Physiology, Heze Medical College, Heze, Shandong Province, China.
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Todaka H, Tatsukawa T, Hashikawa T, Yanagawa Y, Shibuki K, Nagao S. Heterotrimeric guanosine triphosphate-binding protein-coupled modulatory actions of motilin on K+ channels and postsynaptic γ-aminobutyric acid receptors in mouse medial vestibular nuclear neurons. Eur J Neurosci 2012; 37:339-50. [PMID: 23136934 DOI: 10.1111/ejn.12051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 09/24/2012] [Accepted: 10/01/2012] [Indexed: 11/29/2022]
Abstract
Some central nervous system neurons express receptors of gastrointestinal hormones, but their pharmacological actions are not well known. Previous anatomical and unit recording studies suggest that a group of cerebellar Purkinje cells express motilin receptors, and motilin depresses the spike discharges of vestibular nuclear neurons that receive direct cerebellar inhibition in rats or rabbits. Here, by the slice-patch recording method, we examined the pharmacological actions of motilin on the mouse medial vestibular nuclear neurons (MVNs), which play an important role in the control of ocular reflexes. A small number of MVNs, as well as cerebellar floccular Purkinje cells, were labeled with an anti-motilin receptor antibody. Bath application of motilin (0.1 μm) decreased the discharge frequency of spontaneous action potentials in a group of MVNs in a dose-dependent manner (K(d) , 0.03 μm). The motilin action on spontaneous action potentials was blocked by apamin (100 nm), a blocker of small-conductance Ca(2+) -activated K(+) channels. Furthermore, motilin enhanced the amplitudes of inhibitory postsynaptic currents (IPSCs) and miniature IPSCs, but did not affect the frequencies of miniature IPSCs. Intracellular application of pertussis toxin (PTx) (0.5 μg/μL) or guanosine triphosphate-γ-S (1 mm) depressed the motilin actions on both action potentials and IPSCs. Only 30% of MVNs examined on slices obtained from wild-type mice, but none of the GABAergic MVNs that were studied on slices obtained from vesicular γ-aminobutyric acid transporter-Venus transgenic mice, showed such a motilin response on action potentials and IPSCs. These findings suggest that motilin could modulate small-conductance Ca(2+) -activated K(+) channels and postsynaptic γ-aminobutyric acid receptors through heterotrimeric guanosine triphosphate-binding protein-coupled receptor in a group of glutamatergic MVNs.
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Affiliation(s)
- Hiroshi Todaka
- Laboratory for Motor Learning Control, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-Shi, Saitama, 351-0198, Japan
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Lee J, Lee J, Shin H, Kim KS, Lee E, Koh B, Jang HJ. Suggestion of new possibilities in approaching individual variability in appetite through constitutional typology: a pilot study. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 12:122. [PMID: 22889232 PMCID: PMC3502388 DOI: 10.1186/1472-6882-12-122] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 08/05/2012] [Indexed: 11/30/2022]
Abstract
Background Appetite is intricately connected to eating behaviors and shows a high individual variability. In an attempt to approach the problem of gut hormone profiles, appetite, and eating behaviors at the individual level, we have adopted a constitutional typing system widely used in traditional East-Asian medicine, the Sasang constitutional typology, in order to determine the individual variations in appetite, eating behavior, and weight change. Methods This pilot study was designed to investigate the variability of appetite among individuals by tracking the gut hormone patterns across different constitutional types. Pre- and post-prandial concentrations of anorectic (peptide YY (PYY), glucagon-like peptide 1 (GLP-1)) and orexigenic (active ghrelin) gut hormones were measured in healthy, normal-weight (18.5 kg/m2 ≤BMI <23 kg/m2) male subjects aged 20–35 (Soyang (SY) (n = 9), Taeeum (TE) (n = 9), and Soeum (SE) (n = 10) constitutional types). Results Significant differences were found only in the PYY concentrations across the three groups (p = 0.031). The PYY concentration peaked at 30-min post-prandial in the SE group and was significantly higher compared to the other two groups (p = 0.004). The GLP-1 concentration peaked at 15-min post-prandial in the SE group (not significant). The ghrelin levels at 30-min pre-prandial were relatively lower in the TE group compared to the other groups (not significant). Conclusions In conclusion, although with weak statistical power, meaningful gut hormone patterns specific to each constitutional type were discovered in this pilot study, which could offer a new method of approaching the problem of appetite and eating behavior from the angle of individual variability in appetite.
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9-Dihydroerythromycin ethers as motilin agonists—Developing structure–activity relationships for potency and safety. Bioorg Med Chem 2010; 18:7651-8. [DOI: 10.1016/j.bmc.2010.08.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 08/09/2010] [Accepted: 08/14/2010] [Indexed: 01/13/2023]
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Liu H, Qiu D, Zhou X, Niu W, Qin X, Cai Y, Wang J, Chen Y. Erythromycin inhibited glycinergic inputs to gastric vagal motoneurons in brainstem slices of newborn rats. Neurogastroenterol Motil 2010; 22:1232-9. [PMID: 20731779 DOI: 10.1111/j.1365-2982.2010.01586.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND Motilin has been known to stimulate the motility of digestive organs peripherally via activation of motilin receptors located at gastrointestinal (GI) cholinergic nerve endings and/or smooth muscle cells. Recent studies have indicated that motilin may also promote GI motility via actions in the central nervous system; however the sites of action and the mechanisms are not clear yet. The present study aimed to test the hypothesis that motilin receptor agonist erythromycin alters the synaptic inputs of preganglionic gastric vagal motoneurons (GVMs) located in the dorsal motor nucleus of the vagus (DMV). METHODS Gastric vagal motoneurons were retrogradely labeled by fluorescent tracer from the stomach wall of newborn rats. Fluorescently labeled GVMs in DMV were recorded using whole-cell patch-clamp in brainstem slices and the effects of motilin receptor agonist erythromycin on the synaptic inputs were examined. KEY RESULTS Erythromycin (100 nmol L(-1), 1 μmol L(-1), 10 μmol L(-1)) significantly inhibited the frequency of glycinergic spontaneous inhibitory postsynaptic currents (sIPSCs) of GVMs and significantly inhibited the amplitude at the concentration of 10 μmol L(-1). These responses were prevented by GM-109, a selective motilin receptor antagonist. In the pre-existence of tetradotoxin (TTX, 1 μmol L(-1)), erythromycin (10 μmol L(-1)) caused significant decreases of the glycinergic miniature inhibitory postsynaptic currents (mIPSCs), in both the frequency and the amplitude. However, erythromycin (10 μmol L(-1)) didn't cause significant changes of the GABAergic sIPSCs. CONCLUSIONS & INFERENCES Erythromycin selectively inhibits the glycinergic inputs of GVMs.
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Affiliation(s)
- H Liu
- The State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University Shanghai Medical College, Shanghai, China
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Shaw SJ, Chen Y, Zheng H, Fu H, Burlingame MA, Marquez S, Li Y, Claypool M, Carreras CW, Crumb W, Hardy DJ, Myles DC, Liu Y. Structure-activity relationships of 9-substituted-9-dihydroerythromycin-based motilin agonists: optimizing for potency and safety. J Med Chem 2009; 52:6851-9. [PMID: 19821563 DOI: 10.1021/jm901107f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A series of 9-dihydro-9-acetamido-N-desmethyl-N-isopropyl erythromycin A analogues and related derivatives was generated as motilin agonists. The compounds were optimized for potency while showing both minimal antibacterial activity and hERG inhibition. As the substituent on the amide was increased in lipophilicity the potency and hERG inhibition increased, while polar groups lowered potency, without significantly impacting hERG inhibition. The N-methyl acetamide 7a showed the optimal in vitro profile and was probed further by varying the chain length to the macrocycle as well as changing the macrocycle scaffold. 7a remained the compound with the best in vitro properties.
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Affiliation(s)
- Simon J Shaw
- Department of Chemistry, Kosan Biosciences, Inc., Hayward, California 94545, USA.
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14
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Libert N, De Rudnicki S, Cirodde A, Janvier F, Leclerc T, Borne M, Brinquin L. [Promotility drugs use in critical care: indications and limits?]. ACTA ACUST UNITED AC 2009; 28:962-75. [PMID: 19910155 DOI: 10.1016/j.annfar.2009.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Accepted: 08/20/2009] [Indexed: 02/08/2023]
Abstract
Enteral feeding is often limited by gastric and intestinal motility disturbances in critically ill patients, particularly in patients with shock. So, promotility agents are frequently used to improve tolerance to enteral nutrition. This review summaries the pathophysiology, presents the available pharmacological strategies, the clinical data, the counter-indications and the principal limits. The clinical data are poor. No study demonstrates a positive effect on clinical outcomes. Metoclopramide and erythromycin seems to be the more effective. Considering the risk of antibiotic resistance, the first line use of erythromycin should be avoided in favor of metoclopramide.
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Affiliation(s)
- N Libert
- Département d'anesthésie réanimation, hôpital d'instruction des armées du Val-de-Grâce,74, boulevard de Port-Royal, 750005 Paris, France.
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15
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De Smet B, Mitselos A, Depoortere I. Motilin and ghrelin as prokinetic drug targets. Pharmacol Ther 2009; 123:207-23. [DOI: 10.1016/j.pharmthera.2009.04.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Accepted: 04/09/2009] [Indexed: 12/13/2022]
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Abstract
BACKGROUND Previous studies have clearly demonstrated the delayed gastric emptying of solid meals in diabetics, whereas their gastric myoelectrical activity, which primarily determines gastric motility, has not yet been fully confirmed. GOALS This study aimed to clarify the characteristics and potential predictors of gastric myoelectrical activity in type 2 diabetics. STUDY Twenty-eight diabetics and 18 healthy controls participated. Duodenal biopsy sample was used for reverse transcription-polymerase chain reaction to evaluate cholecystokinin and motilin mRNA contents. Electrogastrography was performed before and after the test meal, and was assessed in terms of dominant frequency; dominant frequency instability coefficient; and the percentage of bradygastria, normogastria, and tachygastria. RESULTS Over the entire recording period, dominant frequency was significantly lower, and dominant frequency instability coefficient and the percentage of bradygastria were significantly higher in diabetics than in controls. In diabetics, the multiple regression analysis demonstrated that dominant frequency instability coefficient and the percentage of tachygastria in the fasting period were dependent on fasting plasma glucose level and HbA1c, respectively. Moreover, dominant frequency over the entire period and the postprandial percentage of bradygastria were significantly associated with body mass index; the fasting percentage of bradygastria and postprandial dominant frequency instability coefficient were associated with fasting serum leptin level; the postprandial percentage of bradygastria was also associated with cholecystokinin mRNA content. CONCLUSIONS Gastric myoelectrical activity in type 2 diabetics is impaired on dominant frequency, dominant frequency instability coefficient, and the percentage of bradygastria and predicted by body mass index, fasting serum leptin level, and cholecystokinin mRNA content besides the glycemic status.
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17
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Tsutsui C, Kajihara K, Yanaka T, Sakata I, Itoh Z, Oda SI, Sakai T. House musk shrew (Suncus murinus, order: Insectivora) as a new model animal for motilin study. Peptides 2009; 30:318-29. [PMID: 18996160 DOI: 10.1016/j.peptides.2008.10.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Revised: 10/02/2008] [Accepted: 10/02/2008] [Indexed: 11/24/2022]
Abstract
Although many studies have demonstrated the action of motilin on migrating motor complex by using human subjects and relatively large animals, the precise physiological mechanisms of motilin remain obscure. One reason for the lack of progress in this research field is that large animals are generally not suitable for molecular-level study. To overcome this problem, in this study, we focused on the house musk shrew (Suncus murinus, order: Insectivora, suncus named as laboratory strain) as a small model animal, and we present here the results of motilin gene cloning and its availability for motilin study. The motilin gene has a high homology sequence with that of other mammals, including humans. Suncus motilin is predicted to exist as a 117-residue prepropeptide that undergoes proteolytic cleavage to form a 22-amino-acid mature peptide. The results of RT-PCR showed that motilin mRNA is highly expressed in the upper small intestine, and low levels of expression were found in many tissues. Morphological analysis revealed that suncus motilin-producing cells were present in the upper small intestinal mucosal layer but not in the myenteric plexus. Administration of suncus motilin to prepared muscle strips of rabbit duodenum showed almost the same contractile effect as that of human motilin. Moreover, suncus stomach preparations clearly responded to suncus or human motilin stimulation. To our knowledge, this is the first report that physiological active motilin was determined in small laboratory animals, and the results of this study suggest that suncus is a suitable model animal for studying the motilin-ghrelin family.
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Affiliation(s)
- Chihiro Tsutsui
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku Saitama 338-8570, Japan
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18
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Xu L, Sun X, Depoortere I, Lu J, Guo F, Peeters TL. Effect of motilin on the discharge of rat hippocampal neurons responding to gastric distension and its potential mechanism. Peptides 2008; 29:585-92. [PMID: 18201801 DOI: 10.1016/j.peptides.2007.12.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Revised: 12/03/2007] [Accepted: 12/04/2007] [Indexed: 11/26/2022]
Abstract
The study aims to find the effect of motilin on neuronal activity of gastric distension-responsive neurons in rat hippocampus and its possible mechanism. Single unit discharges in the hippocampal CA1 region were recorded extracellularly by means of four-barrel glass micropipettes in anesthetized rats and the expression of nNOS in hippocampus was observed by fluo-immunohistochemistry staining. Of the 171 recorded neurons, 76.0% were GD-excitatory (GD-E) neurons and 24.0% were GD-inhibited (GD-I) neurons. The 57.6% of GD-E neurons showed an excitatory response to motilin and the same effect was observed in 51.7% GD-I neurons. However, when NOS inhibitor nitro-l-arginine methyl ester (l-NAME) was administrated previously, the followed motilin-induced excitatory responsiveness of GD-responsive neurons was reduced. In contrast, discharge activity of GD-responsive neurons with motilin was enhanced by pretreatment of NO precursor l-arginine. The expression of nNOS-IR positive neurons was significantly increased in CA1 after administration of motilin. Our findings suggested that motilin excited the GD-responsive neurons in the hippocampal CA1 region and the excitatory effect of motilin may be mediated by the endogenous NO.
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Affiliation(s)
- Luo Xu
- Department of Pathophysiology, Medical College of Qingdao University, 38# Dengzhou Road, Qingdao, Shandong 266021, PR China.
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19
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20
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Guan Y, Tang M, Jiang Z, Peeters TL. Excitatory effects of motilin in the hippocampus on gastric motility in rats. Brain Res 2003; 984:33-41. [PMID: 12932837 DOI: 10.1016/s0006-8993(03)03016-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intestinal motilin is known to stimulate gastrointestinal motility. Recently, it was shown that the motilin gene and the motilin receptor are expressed in various regions of the brain. We studied whether motilin can activate pathways in the rat hippocampus to stimulate gastric motility. Gastric motility was monitored in conscious rats, whereas extracellular electrical activity recordings of the hippocampus were performed on anaesthetized rats to measure the influence of microinjection of motilin and CCK-8 into the hippocampus and into the cerebral ventricles. We found that neurons in the CA3 region of the hippocampus are sensitive to gastric distension, and that injection of motilin into the hippocampus increased the amplitude of gastric contractions by 35.3+/-6.8%, while CCK-8 injection inhibited motility by -27.3+/-6.8%. The hippocampal motilin-induced stimulation of gastric motility (30.6+/-5.5%) was completely abolished by subdiaphragmal vagotomy (-2.8+/-4.4%) but unaffected by the intravenously applied receptor blockers atropine, phentolamine and propranolol. In vivo extracellular recordings of gastric distension-responsive CA3 neurons revealed that intracerebroventricular administration of motilin increased firing while CCK-8 inhibited firing. These opposite effects of motilin and CCK-8 fit with the nature of the actions of these gut-brain peptides on gastric motility. Our findings suggest that the stimulation of gastric motility by motilin administered in the hippocampus reflects the existence of a functional interaction between the hippocampus and a vago-vagus reflex running via a noncholinergic and nonadrenergic efferent pathway.
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Affiliation(s)
- Yanfang Guan
- Department of Physiology, Medical College of Qingdao University, Qingdao, 266021, PR China.
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21
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Xu L, Depoortere I, Thielemans L, Huang Z, Tang M, Peeters TL. Sequence, distribution and quantification of the motilin precursor in the cat. Peptides 2003; 24:1387-95. [PMID: 14706554 DOI: 10.1016/j.peptides.2003.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Due to motilin's relation to the migrating motor complex (MMC), the physiology of motilin has been mostly studied in man and dog. The cat does not have an MMC pattern, and little is known about cat motilin. Therefore we identified the cat motilin precursor (GenBank accession no. AF127917) and developed a quantitative polymerase chain reaction (PCR) to explore its distribution in the gastrointestinal tract and in the central nervous system (CNS). The precursor is closely related to the dog precursor and consists of an open reading frame of 348bp encoding the signal peptide (25 amino acids), the motilin sequence (22 amino acids) and the motilin associated peptide (69 amino acids). One amino acid of the signal peptide was subject to gene polymorphism. Quantification of motilin messenger RNA (mRNA) was for the first time achieved. It is most abundant in the gastrointestinal tract, with the highest concentration in the duodenum, the lowest in the colon and is not detectable in the corpus. However an important expression was also observed in several regions of the CNS, except the striatum and cerebral cortex. The highest level was in the hypothalamus (although 23-fold lower than in the duodenum), the lowest level in the pons. Moderate levels were found in the thyroid. These data suggest that the physiological role of motilin may extend beyond its effect on gastrointestinal motility.
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Affiliation(s)
- Luo Xu
- Center for Pathophysilogy, Gastroenterological Research, University of Leuven, Gasthuisberg ON, B-3000 Leuven, Belgium
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22
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Carreras CW, Siani MA, Santi DV, Dillon SB. Stable expression of a synthetic gene for the human motilin receptor: use in an aequorin-based receptor activation assay. Anal Biochem 2002; 300:146-51. [PMID: 11779105 DOI: 10.1006/abio.2001.5466] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A synthetic gene for the human motilin receptor containing 33 unique restriction sites was designed and stably coexpressed in HEK293 cells with the bioluminescent Ca(2+) indicator protein aequorin. The dose-dependent response of the receptor to motilin was demonstrated using transient transfections, and a stable cell line was selected. [(125)I]Motilin binding was used to estimate receptor expression level for the stable cell line, and titration of a membrane preparation indicated a K(d) value of 0.8 nM. The same cell line was used to evaluate a panel of erythromycin-derived agonists and provided EC(50) values for receptor activation that agree closely with data obtained in contractility assays. The peptide antagonist ANQ11125 (Phe3Leu13 motilin 1-14) inhibited motilin induced response with a K(i) value of 10 nM. The system is well-suited for the screening of compound libraries and receptor mutagenesis studies.
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Affiliation(s)
- Christopher W Carreras
- Department of Pharmacological Sciences, Kosan Biosciences, Inc., 3832 Bay Center Place, Hayward, California 94545, USA.
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23
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Affiliation(s)
- A Inui
- Division of Diabetes, Digestive and Kidney Diseases, Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
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Thielemans L, Depoortere I, Van Assche G, Bender E, Peeters TL. Demonstration of a functional motilin receptor in TE671 cells from human cerebellum. Brain Res 2001; 895:119-28. [PMID: 11259768 DOI: 10.1016/s0006-8993(01)02055-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Our laboratory has described the presence of motilin receptors in the rabbit cerebellum. We discovered its presence in the human TE671 cell line, which is of cerebellar origin. METHODS Cytosolic Ca(2+) fluxes were monitored on a confocal microscope in cells loaded with Indo-1 and stimulated with motilin under various conditions. Binding studies were performed with 125I-[Nle(13)]porcine motilin. Using primers, PCR for the motilin receptor was performed. RESULTS Cells responded to motilin after 45+/-20 s. At different concentrations of motilin (10(-8), 10(-7), 10(-6.5), 10(-6) and 10(-5) M) the percentage of responding cells was 0+/-0, 0.6+/-1.5, 4.9+/-4.7, 21.7+/-15 and 35.7+/-12, respectively. The response was blocked by the motilin antagonists [Phe(3), Nle(13)]po-motilin (0.8+/-1.8%) and GM-109 (0.0+/-0.0%) and mimicked by the agonist ABT-229 (23.6+/-15%). After stimulation with motilin, ABT-229 or [Phe(3),Leu(13)]po-motilin, but not with the antagonist GM-109, cells were desensitized. The response to motilin persisted in Ca(2+)-free solution (22.8+/-14.7%), was not affected by nifedipine (44+/-11%) but was abolished by incubation with thapsigargin (0+/-0%). Neither ryanodine, nor a previous stimulation with caffeine (0+/-0%) in Ca(2+)-free Krebs, nor both could block the response to motilin (28, 32.0+/-5.7, 41.3+/-6.1%, respectively). Binding studies revealed two binding sites for motilin, with a pK(d) of 8.9+/-0.05 and 6.11+/-0.61 (n=4). There were 100 times more low than high affinity receptors per cell. The presence of receptor mRNA was confirmed by PCR. CONCLUSION Functional motilin receptors are present in TE671 cells. The response requires intracellular IP(3)-sensitive Ca(2+) stores. These cells may serve as a model of the central motilin receptor.
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Affiliation(s)
- L Thielemans
- Gut Hormone Laboratory, Center for Gastroenterological Research, Department of Pathophysiology, Katholieke Universiteit Leuven, Gasthuisberg O & N, Herestraat 49, Leuven B-3000, Belgium
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25
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Depoortere I, Thijs T, Thielemans L, Keith JC, Van Assche G, Peeters TL. Effect of recombinant human interleukin-11 on motilin and substance P release in normal and inflamed rabbits. REGULATORY PEPTIDES 2001; 97:111-9. [PMID: 11164946 DOI: 10.1016/s0167-0115(00)00190-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Recombinant human interleukin-11 (rhIL-11) normalizes depressed smooth muscle tension generation towards motilin and substance P (SP) in rabbits with colitis. The aim of this paper was to evaluate the effect of rhIL-11 treatment on motilin and SP release which could have an effect on the contractility changes. Rabbits received 4, 40, 72 or 720 microg/kg rhIL-11 s.c. or saline, 1 h later a continuous s.c. administration of rhIL-11 was started with or without the induction of colitis (135 mg/kg TNBS) for 5 days. Motilin and SP levels were measured by RIA, motilin mRNA expression by RT-PCR. TNBS-colitis did not affect plasma motilin levels but increased the motilin content of the duodenal mucosa 1.7-fold. rhIL-11 treatment dose-dependently increased plasma motilin levels (720 microg/kg day: 3.5-fold) and the motilin content of the duodenal mucosa (720 microg/kg day: 3.0-fold). The effects of rhIL-11 were similar in normal rabbits and were accompanied by an increased motilin mRNA expression. TNBS-colitis decreased plasma SP levels 2.7-fold and the SP content in the colonic muscle layer 7.1-fold. The decrease in the muscle layer, but not in the plasma, was normalized by rhIL-11 treatment. In normal rabbits, rhIL-11 caused a decrease in plasma SP levels, but had no effect on the tissue content of SP. In conclusion, treatment of inflamed or normal rabbits with rhIL-11 increases plasma and tissue levels of motilin in the duodenal mucosa via an increased expression of motilin in the endocrine cells and induces the release of SP from extrinsic neurons. These changes do not explain the beneficial effect of rhIL-11 on the lowered contractility in inflamed rabbits although a change in balance of neuropeptides may influence gastro-intestinal inflammation.
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Affiliation(s)
- I Depoortere
- Centre for Gastroenterological Research, Department of Pathophysiology, University of Leuven, Gasthuisberg O&N, B-3000 Leuven, Belgium
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26
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Xu L, Depoortere I, Tang M, Peeters TL. Identification and expression of the motilin precursor in the guinea pig. FEBS Lett 2001; 490:7-10. [PMID: 11172801 DOI: 10.1016/s0014-5793(01)02125-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Motilin has never been isolated from rodents, the most frequently used laboratory animals, despite several attempts. We have isolated and sequenced the motilin precursor from duodenal mucosa of guinea pig (GenBank accession number AF323752) and studied its expression in several tissues. The percent homology with human motilin is the lowest yet observed due to several unique substitutions in the C-terminal end. As expected, the precursor was present in the gut mucosa with the exception of the gastric corpus. It was also present in medulla oblongata, nucleus of the solitary tract, hypophysis, spinal cord, hypothalamus, and cerebellum but not in the cerebral cortex. For the first time we demonstrated motilin expression in the thyroid.
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Affiliation(s)
- L Xu
- Gut Hormone Laboratory, University of Leuven, Gasthuisberg ON, B-3000 Leuven, Belgium
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27
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Huang Z, Depoortere I, De Clercq P, Peeters T. Sequence and characterization of cDNA encoding the motilin precursor from chicken, dog, cow and horse. Evidence of mosaic evolution in prepromotilin. Gene 1999; 240:217-26. [PMID: 10564829 DOI: 10.1016/s0378-1119(99)00397-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Motilin is involved in the regulation of the fasting motility pattern in man and in dog, but may have a different role in other species. Immunoreactive motilin has been demonstrated in several species, but the sequence is mostly unknown. The aim of this study was to isolate and sequence the cDNA encoding the motilin precursor from several mammalian species and from chicken. Total RNA was isolated from the duodenal mucosa of the chicken, dog, cow and horse. In each case single stranded cDNA was synthesized. Motilin cDNA fragments were amplified by PCR, ligated into a plasmid and cloned. Clones which were positive after screening with an appropriate (32)P-labeled probe were sequenced. The 5'- and 3'-ends were determined by the rapid amplification of cDNA ends (RACE) method. Analysis of the cDNAs revealed an open reading frame coding for 115 (chicken and cow), or 117 (dog and horse) amino acids. It consists of a 25 amino acid signal peptide, motilin itself, and a 68 (chicken and cow) or 70 (dog and horse) amino acid motilin associated peptide (MAP). As in all motilin precursors already sequenced (man, monkey, pig and rabbit), an endoproteinase cleavage site is present at Lys(23)-Lys(24). Comparison of all known sequences shows considerable identity in amino acid and nucleotide sequence of the signal peptide and motilin. However, the MAPs differ not only in length but also, more strongly, in amino acid and nucleotide sequence. Our study demonstrates that the N- and C-terminal regions of the motilin precursor have evolved at different rates, which is evidence for 'mosaic evolution'.
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Affiliation(s)
- Z Huang
- Gut Hormone Lab, Department of Pathophysiology, Catholic University of Leuven, Gasthuisberg O and N, Herestraat 49, B-3000, Leuven, Belgium
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28
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Huang Z, De Clercq P, Depoortere I, Peeters TL. Isolation and sequence of cDNA encoding the motilin precursor from monkey intestine. Demonstration of the motilin precursor in the monkey brain. FEBS Lett 1998; 435:149-52. [PMID: 9762897 DOI: 10.1016/s0014-5793(98)01056-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The motilin precursor cDNA has been isolated and sequenced from a cDNA library prepared from monkey small intestine. The sequence indicates a 345 bp open reading frame, a 63 bp 5' untranslated region and a 154 bp 3' untranslated region. The sequence encodes a 115 amino acid motilin precursor composed of a 25 amino acid signal peptide, the 22 amino acid motilin peptide and a 68 amino acid motilin associated peptide (MAP). Compared with the human motilin precursor cDNA, there are two amino acid substitutions in the signal peptide, one in motilin and four in the MAP. The presence of the motilin precursor in hypothalamus, hippocampus and cerebellum was demonstrated by RT-PCR.
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Affiliation(s)
- Z Huang
- Gut Hormone Lab, University of Leuven, Belgium
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29
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Momose K, Inui A, Asakawa A, Ueno N, Nakajima M, Kasuga M. Anxiolytic effect of motilin and reversal with GM-109, a motilin antagonist, in mice. Peptides 1998; 19:1739-42. [PMID: 9880080 DOI: 10.1016/s0196-9781(98)00131-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
There have been few reports on the effects of the brain-gut peptide motilin on the central nervous system (CNS). We administered motilin intracerebroventricularly to mice and investigated the effect of motilin on anxiety using an elevated plus-maze. Motilin produced a significant decrease in anxiety with an inverted U-shaped dose response. To determine whether the anxiolytic effect of motilin was mediated via motilin receptors in the brain, the effect of GM-109, a novel motilin receptor antagonist, was investigated. GM-109 showed a significant and dose-dependent antagonism on the motilin-induced anxiolytic effect. GM-109 administered alone had no effect on anxiety. These results suggest that motilin receptors are present in the brain and may have a role in anxiety and emotion.
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Affiliation(s)
- K Momose
- Second Department of Internal Medicine, Kobe University School of Medicine, Japan
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