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Bandla A, Melancon E, Taylor CR, Davidson AE, Eisen JS, Ganz J. A New Transgenic Tool to Study the Ret Signaling Pathway in the Enteric Nervous System. Int J Mol Sci 2022; 23:15667. [PMID: 36555308 PMCID: PMC9779438 DOI: 10.3390/ijms232415667] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 11/23/2022] [Accepted: 12/02/2022] [Indexed: 12/14/2022] Open
Abstract
The receptor tyrosine kinase Ret plays a critical role in regulating enteric nervous system (ENS) development. Ret is important for proliferation, migration, and survival of enteric progenitor cells (EPCs). Ret also promotes neuronal fate, but its role during neuronal differentiation and in the adult ENS is less well understood. Inactivating RET mutations are associated with ENS diseases, e.g., Hirschsprung Disease, in which distal bowel lacks ENS cells. Zebrafish is an established model system for studying ENS development and modeling human ENS diseases. One advantage of the zebrafish model system is that their embryos are transparent, allowing visualization of developmental phenotypes in live animals. However, we lack tools to monitor Ret expression in live zebrafish. Here, we developed a new BAC transgenic line that expresses GFP under the ret promoter. We find that EPCs and the majority of ENS neurons express ret:GFP during ENS development. In the adult ENS, GFP+ neurons are equally present in females and males. In homozygous mutants of ret and sox10-another important ENS developmental regulator gene-GFP+ ENS cells are absent. In summary, we characterize a ret:GFP transgenic line as a new tool to visualize and study the Ret signaling pathway from early development through adulthood.
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Affiliation(s)
- Ashoka Bandla
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Ellie Melancon
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Charlotte R. Taylor
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ann E. Davidson
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Judith S. Eisen
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Julia Ganz
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA
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2
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Pathophysiology of Diverticular Disease: From Diverticula Formation to Symptom Generation. Int J Mol Sci 2022; 23:ijms23126698. [PMID: 35743141 PMCID: PMC9223421 DOI: 10.3390/ijms23126698] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/13/2022] [Accepted: 06/13/2022] [Indexed: 01/04/2023] Open
Abstract
Diverticular disease is a common clinical problem, particularly in industrialized countries. In most cases, colonic diverticula remain asymptomatic throughout life and sometimes are found incidentally during colonic imaging in colorectal cancer screening programs in otherwise healthy subjects. Nonetheless, roughly 25% of patients bearing colonic diverticula develop clinical manifestations. Abdominal symptoms associated with diverticula in the absence of inflammation or complications are termed symptomatic uncomplicated diverticular disease (SUDD). The pathophysiology of diverticular disease as well as the mechanisms involved in the shift from an asymptomatic condition to a symptomatic one is still poorly understood. It is accepted that both genetic factors and environment, as well as intestinal microenvironment alterations, have a role in diverticula development and in the different phenotypic expressions of diverticular disease. In the present review, we will summarize the up-to-date knowledge on the pathophysiology of diverticula and their different clinical setting, including diverticulosis and SUDD.
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3
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Bodin R, Paillé V, Oullier T, Durand T, Aubert P, Le Berre-Scoul C, Hulin P, Neunlist M, Cissé M. The ephrin receptor EphB2 regulates the connectivity and activity of enteric neurons. J Biol Chem 2021; 297:101300. [PMID: 34648765 PMCID: PMC8569587 DOI: 10.1016/j.jbc.2021.101300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 10/01/2021] [Accepted: 10/08/2021] [Indexed: 11/29/2022] Open
Abstract
Highly organized circuits of enteric neurons are required for the regulation of gastrointestinal functions, such as peristaltism or migrating motor complex. However, the factors and molecular mechanisms that regulate the connectivity of enteric neurons and their assembly into functional neuronal networks are largely unknown. A better understanding of the mechanisms by which neurotrophic factors regulate this enteric neuron circuitry is paramount to understanding enteric nervous system (ENS) physiology. EphB2, a receptor tyrosine kinase, is essential for neuronal connectivity and plasticity in the brain, but so far its presence and function in the ENS remain largely unexplored. Here we report that EphB2 is expressed preferentially by enteric neurons relative to glial cells throughout the gut in rats. We show that in primary enteric neurons, activation of EphB2 by its natural ligand ephrinB2 engages ERK signaling pathways. Long-term activation with ephrinB2 decreases EphB2 expression and reduces molecular and functional connectivity in enteric neurons without affecting neuronal density, ganglionic fiber bundles, or overall neuronal morphology. This is highlighted by a loss of neuronal plasticity markers such as synapsin I, PSD95, and synaptophysin, and a decrease of spontaneous miniature synaptic currents. Together, these data identify a critical role for EphB2 in the ENS and reveal a unique EphB2-mediated molecular program of synapse regulation in enteric neurons.
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Affiliation(s)
- Raphael Bodin
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Vincent Paillé
- UMR 1280 Physiologie des Adaptations Nutritionnelles, INRA, Institut des Maladies de l'Appareil Digestif, Université de Nantes, Nantes, France
| | - Thibauld Oullier
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Tony Durand
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Philippe Aubert
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Catherine Le Berre-Scoul
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | | | - Michel Neunlist
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Moustapha Cissé
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France.
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4
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Abdominal Massage Reduces Visceral Hypersensitivity via Regulating GDNF and PI3K/AKT Signal Pathway in a Rat Model of Irritable Bowel Syndrome. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:3912931. [PMID: 32565856 PMCID: PMC7293735 DOI: 10.1155/2020/3912931] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/29/2020] [Accepted: 05/13/2020] [Indexed: 12/30/2022]
Abstract
Changes in gut motility and visceral hypersensitivity are two major features of irritable bowel syndrome (IBS). Current drug treatments are often poorly efficacious, with many side effects for patients with IBS. Complementary therapies, such as acupuncture or abdominal massage, have received more attention in recent years. In this study, a rat model of IBS with diarrhea (IBS-D) was established by instillation of acetic acid from the colon. The effects of abdominal massage on changes in gut motility, visceral hypersensitivity, and the possible mechanism were investigated. Continuous abdominal massage could decrease the stool consistency score and increase the efflux time of glass beads compared with model groups, while also decreasing mast cell counts in IBS-D rats. The mRNA and protein expressions of neuronal nitric oxide synthase (nNOS), choline acetyl transferase (CHAT), and protein gene product 9.5 (PGP9.5) were significantly upregulated by continuous abdominal massage compared with model groups. Continuous abdominal massage also improved the ultrastructure of enteric glial cells (EGCs) by decreasing the number of mitochondria and increasing the level of the heterochromatin. Meanwhile, continuous abdominal massage could upregulate the expression of glial cell line-derived neurotrophic factor (GDNF) and P-Akt/Akt. Furthermore, it could reduce visceral hypersensitivity and improve the IBS-D symptoms by regulating the phosphoinositide 3-kinase (PI3K)-Akt pathway, which would provide a novel method for the treatment of IBS-D in the clinical setting.
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5
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Schemann M, Frieling T, Enck P. To learn, to remember, to forget-How smart is the gut? Acta Physiol (Oxf) 2020; 228:e13296. [PMID: 31063665 DOI: 10.1111/apha.13296] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 04/29/2019] [Accepted: 05/02/2019] [Indexed: 12/19/2022]
Abstract
The enteric nervous system (ENS) resides within the gut wall and autonomously controls gut functions through coordinated activation of sensory, inter and motor neurons. Its activity is modulated by the enteric immune and endocrine system as well as by afferent and efferent nerves of the parasympathetic and sympathetic nervous system. The ENS is often referred to as the second brain and hence is able to perform sophisticated tasks. We review the evidence that the "smartness" of the ENS may even extend to its ability to learn and to memorize. Examples for habituation, sensitization, conditioned behaviour and long-term facilitation are evidence for various forms of implicit learning. Moreover, we discuss how this may change not only basic Neurogastroenterology but also our understanding of development of gut diseases and chronic disorders in gut functions. At the same time, we identify open questions and future challenges to confirm learning, memory and memory deficits in the gut. Despite some remaining experimental challenges, we are convinced that the gut is able to learn and are tempted to answer the question with: Yes, the gut is smart.
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Affiliation(s)
| | | | - Paul Enck
- Department of Internal Medicine VI, Psychosomatic Medicine and Psychotherapy University Hospital Tübingen Tübingen Germany
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6
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Wang S, Fan Y, Xu Y, Zhang L, Cai L, Lv B. GDNFOS1 knockdown decreases the invasion and viability of glioblastoma cells. Exp Ther Med 2019; 18:1315-1322. [PMID: 31316623 DOI: 10.3892/etm.2019.7670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 05/10/2019] [Indexed: 01/12/2023] Open
Abstract
Glioblastoma multiforme is the most aggressive primary brain cancer in adults. Therefore, it is important to investigate the mechanisms associated with cell viability and invasion ability of the cells in glioblastoma multiforme. The opposite strand of the glial cell line-derived neurotrophic factor (GDNF) gene is used to transcribe the cis-antisense GDNF opposite strand (GDNFOS) gene, which belongs to the long noncoding RNAs. The current study assessed the effects of GDNFOS1 overexpression and interference on GDNF expression, cell viability and invasion ability in U87 and U251 MG glioblastoma cells. Overexpression and interference were performed using constructed lentiviral vectors, including long non-coding RNA GDNFOS1 overexpression vector, pL-short hairpin RNA (shRNA)-GDNFOS1-9, pL-shRNA-GDNFOS1-49, pL-shRNA-GDNFOS1-248, pL-shRNA-GDNFOS1-9+49, pL-shRNA-GDNFOS1-9+248 and pL-shRNA-GDNFOS1-49+248. Reverse transcription-quantitative PCR was used to determine the efficiency of interference and overexpression of GDNFOS1 in U87 and U251 MG cells. GDNF protein expression in U87 and U251 MG cells was detected using western blot analysis. In addition, cell viability was detected using a cell counting kit-8 assay at 24, 48 and 72 h after GDNFOS1 overexpression or interference. A transwell invasion assay was used to detect invasion ability. Different shRNA sequences were tested and the results revealed that a combination (pL-shRNA-GDNFOS1-49+248) was most effective in the knock-down GDNFOS1. Compared with the control group, GDNF expression in U87 MG cells was significantly increased in the GDNFOS1 overexpression group and decreased in the shRNA-GDNFOS1-248 group. U87 MG cell viability was significantly increased in the GDNFOS1 overexpression group at 24, 48 and 72 h compared with the negative control group. The viability of U87 MG cells was decreased in the GDNFOS1 interference group at 72 h when compared with the control group. The relative invasive ability was significantly increased in the GDNFOS1 overexpression group when compared with the negative control group. The invasive ability was significantly decreased in the GDNFOS1 interference group when compared with the negative control group. Similar results were exhibited by the U251 MG cells. Overall, GDNF expression, cell viability and invasion ability of glioblastoma cells significantly increased with GDNFOS1 overexpression and decreased with GDNFOS1 interference.
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Affiliation(s)
- Shiyi Wang
- Department of Gastroenterology, Ningbo Hospital of TCM Affiliated to Zhejiang Chinese Medical University, Ningbo, Zhejiang 315000, P.R. China.,Department of Gastroenterology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
| | - Yihong Fan
- Department of Gastroenterology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
| | - Yi Xu
- Department of Gastroenterology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
| | - Lu Zhang
- Department of Gastroenterology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
| | - Lijun Cai
- Department of Gastroenterology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
| | - Bin Lv
- Department of Gastroenterology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
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7
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Russell JP, Mohammadi E, Ligon C, Latorre R, Johnson AC, Hoang B, Krull D, Ho MWY, Eidam HS, DeMartino MP, Cheung M, Oliff AI, Kumar S, Greenwood-Van Meerveld B. Enteric RET inhibition attenuates gastrointestinal secretion and motility via cholinergic signaling in rat colonic mucosal preparations. Neurogastroenterol Motil 2019; 31:e13479. [PMID: 30311722 DOI: 10.1111/nmo.13479] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 08/14/2018] [Accepted: 09/01/2018] [Indexed: 12/23/2022]
Abstract
BACKGROUND The expression of RET in the developing enteric nervous system (ENS) suggests that RET may contribute to adult intestinal function. ENS cholinergic nerves play a critical role in the control of colonic function through the release of acetylcholine (ACh). In the current study, we hypothesized that a RET-mediated mechanism may regulate colonic ion transport and motility through modulation of cholinergic nerves. METHODS The effect of RET inhibition on active ion transport was assessed electrophysiologically in rat colonic tissue mounted in Ussing chambers via measurements of short circuit current (Isc) upon electrical field stimulation (EFS) or pharmacologically with cholinergic agonists utilizing a gastrointestinal (GI)-restricted RET inhibitor. We assessed the effect of the RET inhibitor on propulsive motility via quantification of fecal pellet output (FPO) induced by the acetylcholinesterase inhibitor neostigmine. KEY RESULTS We found that enteric ganglia co-expressed RET and choline acetyltransferase (ChAT) transcripts. In vitro, the RET kinase inhibitor GSK3179106 attenuated the mean increase in Isc induced by either EFS or carbachol but not bethanechol. In vivo, GSK3179106 significantly reduced the prokinetic effect of neostigmine. CONCLUSION AND INFERENCES Our findings provide evidence that RET-mediated mechanisms regulate colonic function by maintaining cholinergic neuronal function and enabling ACh-evoked chloride secretion and motility. We suggest that modulating the cholinergic control of the colon via a RET inhibitor may represent a novel target for the treatment of intestinal disorders associated with increased secretion and accelerated GI transit such as irritable bowel syndrome with diarrhea (IBS-D).
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Affiliation(s)
- John P Russell
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania
| | - Ehsan Mohammadi
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Casey Ligon
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Rocco Latorre
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Anthony C Johnson
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Bao Hoang
- Exploratory Biomarker Assay Group, GlaxoSmithKline, Collegeville, Pennsylvania
| | - David Krull
- Exploratory Biomarker Assay Group, GlaxoSmithKline, Collegeville, Pennsylvania
| | - Melisa W-Y Ho
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania
| | - Hilary S Eidam
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania
| | - Michael P DeMartino
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania
| | - Mui Cheung
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania
| | - Allen I Oliff
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania
| | - Sanjay Kumar
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania
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8
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Ko SY, Price JT, Blatch GL, Nurgali K. Netrin-1-like-immunoreactivity Coexpresses With DCC and Has a Differential Level in the Myenteric Cholinergic and Nitrergic Neurons of the Adult Mouse Colon. J Histochem Cytochem 2018; 67:335-349. [PMID: 30576266 DOI: 10.1369/0022155418819821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Netrin-1 is a potent axonal and neuronal guidance cue in the developing nervous system. Netrin-1 functions are mediated by its receptors, such as deleted in colorectal cancer (DCC) present on axons and neurons. Localization of DCC and Netrin-1 on various types of enteric neurons and their role in the mature enteric nervous system is unknown. The results of our study revealed that almost all enteric neurons and processes express DCC and Netrin-1 in the adult mice. Netrin-1-like-immunoreactivity (IR) was detected in the cytoplasm of neurons with some showing strong or weak staining. The majority of Netrin-1-like-immunoreactive enteric neurons were choline acetyltransferase (ChAT)-positive. However, ~19% of neurons were strongly Netrin-1-like-positive but ChAT-negative while ~8% of neurons were Netrin-1-like-negative but strongly ChAT-positive. In contrast, almost all nitric oxide synthase (nNOS)-positive enteric neurons displayed strong Netrin-1-like-IR. This differential intensity of Netrin-1 expression in the myenteric neurons might determine major neuronal subtypes regulating intestinal motility, ChAT-IR excitatory, and nNOS-IR inhibitory muscle motor and interneurons. This is the first study demonstrating the localization of DCC and Netrin-1 in the colonic myenteric plexus of the adult mice and their expression level determining two major neuronal subtypes regulating intestinal motility.
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Affiliation(s)
- Suh Youn Ko
- College of Health and Biomedicine, Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia
| | - John T Price
- College of Health and Biomedicine, Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia.,Australian Institute for Musculoskeletal Science.,Department of Medicine-Western Health, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Gregory L Blatch
- College of Health and Biomedicine, Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia.,The Vice Chancellery, The University of Notre Dame Australia, Fremantle, Western Australia, Australia.,Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
| | - Kulmira Nurgali
- College of Health and Biomedicine, Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia.,Australian Institute for Musculoskeletal Science.,Department of Medicine-Western Health, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia
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9
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Abstract
Enteric glial cells (EGCs) are an important part of the enteric nervous system and play an important role in maintaining gastrointestinal function. They can nourish and support gastrointestinal neurons, participate in the integration and regulation of neural activities in the gastrointestinal tract, mediate intestinal inflammation, and directly or indirectly regulate gastrointestinal motor function. Investigating the effect of EGCs on neurons and their role in intestinal inflammation caused by gastrointestinal movement disorders may help to reveal the mechanism underlying the impact of EGCs on gastrointestinal dynamics. In clinical practice, EGCs have the potential to be used as a therapeutic target for various gastrointestinal motor function disorders. This review will summarize current knowledge regarding the effect of EGCs on gastrointestinal motor function.
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Affiliation(s)
- Ying Xu
- Department of Emergency Abdominal Surgery, the First Affiliated Hospital of Dalian Medical University / Institute of Integrative Medicine, Dalian 116000, Liaoning Province, China
| | - Ming-Zheng Xie
- Department of Emergency Abdominal Surgery, the First Affiliated Hospital of Dalian Medical University / Institute of Integrative Medicine, Dalian 116000, Liaoning Province, China
| | - Guo-Gang Liang
- Department of Emergency Abdominal Surgery, the First Affiliated Hospital of Dalian Medical University / Institute of Integrative Medicine, Dalian 116000, Liaoning Province, China
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10
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Zhang L, Song J, Bai T, Wang R, Hou X. Sustained pain hypersensitivity in the stressed colon: Role of mast cell-derived nerve growth factor-mediated enteric synaptic plasticity. Neurogastroenterol Motil 2018; 30:e13430. [PMID: 30069980 DOI: 10.1111/nmo.13430] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 05/23/2018] [Accepted: 06/22/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Sustained pain hypersensitivity is the hallmark of stressed colon which could be partially explained by central sensitization with synaptic plasticity, the key mechanism of memory. We previously identified that synaptic plasticity of enteric nerve system (ENS) contributed to peripheral pain maintaining in the gut. However, the mechanisms of enteric "memory" formation remain elusive. METHODS In this study, rats were exposed to water avoidance stress (WAS) or sham stress (SS), with cromolyn sodium or physiological saline injected intraperitoneally 30 minutes before stress every day. The abdominal withdrawal reflex scores, mesenteric afferent nerve activity, enteric neural c-fos expression, and enteric synaptic plasticity were assessed, and mast cell infiltration and degranulation. Furthermore, colonic mucosal mediators-induced enteric synaptic plasticity and the role of mast cell-derived nerve growth factor (NGF), tryptase, and histamine were investigated via ex vivo longitudinal muscle-myenteric plexus (LMMP) organotypic culture. KEY RESULTS It is shown that mast cell stabilizing inhibited WAS-induced visceral hypersensitivity through enhancing visceral pain threshold, decreasing spontaneous and distention-induced mesenteric afferent firing, and downregulating enteric neural activation (c-fos). Importantly, WAS led to evident enteric synaptic plasticity, but decreased by cromolyn. Water avoidance stress-derived mucosal supernatants markedly enhanced the c-fos expression and enteric synaptic plasticity in LMMP tissues, which could be eliminated by mast cell inhibition or NGF neutralization, but not tryptase or histamine blocking. CONCLUSIONS & INFERENCES In conclusion, mast cells/NGF pathway may be the key regulator of synaptic plasticity of ENS and participate in the formation of chronic stress-induced sustained visceral hypersensitivity.
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Affiliation(s)
- L Zhang
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - J Song
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - T Bai
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - R Wang
- Department of Gerontology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - X Hou
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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11
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Schenck Eidam H, Russell J, Raha K, DeMartino M, Qin D, Guan HA, Zhang Z, Zhen G, Yu H, Wu C, Pan Y, Joberty G, Zinn N, Laquerre S, Robinson S, White A, Giddings A, Mohammadi E, Greenwood-Van Meerveld B, Oliff A, Kumar S, Cheung M. Discovery of a First-in-Class Gut-Restricted RET Kinase Inhibitor as a Clinical Candidate for the Treatment of IBS. ACS Med Chem Lett 2018; 9:623-628. [PMID: 30034590 DOI: 10.1021/acsmedchemlett.8b00035] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 05/21/2018] [Indexed: 02/06/2023] Open
Abstract
Abdominal pain and abnormal bowel habits represent major symptoms for irritable bowel syndrome (IBS) patients that are not adequately managed. Although the etiology of IBS is not completely understood, many of the functions of the gastrointestinal (GI) tract are regulated by the enteric nervous system (ENS). Inflammation or stress-induced expression of growth factors or cytokines may lead to hyperinnervation of visceral afferent neurons in GI tract and contribute to the pathophysiology of IBS. Rearranged during transfection (RET) is a neuronal growth factor receptor tyrosine kinase critical for the development of the ENS as exemplified by Hirschsprung patients who carry RET loss-of-function mutations and lack normal colonic innervation leading to colonic obstruction. Similarly, RET signaling in the adult ENS maintains neuronal function by contributing to synaptic formation, signal transmission, and neuronal plasticity. Inhibition of RET in the ENS represents a novel therapeutic strategy for the normalization of neuronal function and the symptoms of IBS patients. Herein, we describe our screening effort and subsequent structure-activity relationships (SARs) in optimizing potency, selectivity, and mutagenicity of the series, which led to the discovery of a first-in-class, gut-restricted RET kinase inhibitor, 2-(4-(4-ethoxy-6-oxo-1,6-dihydropyridin-3-yl)-2-fluorophenyl)-N-(5-(1,1,1-trifluoro-2-methylpropan-2-yl)isoxazol-3-yl)acetamide (15, GSK3179106), as a clinical candidate for the treatment of IBS. GSK3179106 is a potent, selective, and gut-restricted pyridone hinge binder small molecule RET kinase inhibitor with a RET IC50 of 0.3 nM and is efficacious in vivo.
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Affiliation(s)
- Hilary Schenck Eidam
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania 19406, United States
| | - John Russell
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania 19406, United States
| | - Kaushik Raha
- Computational Chemistry, GlaxoSmithKline, King of Prussia, Pennsylvania 19406, United States
| | - Michael DeMartino
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania 19406, United States
| | - Donghui Qin
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania 19406, United States
| | | | | | | | | | | | - Yan Pan
- WuXi AppTec, Shanghai, China
| | - Gerard Joberty
- Cellzome GmbH, a GSK company, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Nico Zinn
- Cellzome GmbH, a GSK company, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Sylvie Laquerre
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania 19406, United States
| | - Sharon Robinson
- Genetic Toxicology, GlaxoSmithKline, Ware, Hertfordshire, United Kingdom
| | - Angela White
- Computational Toxicology, GlaxoSmithKline, Ware, Hertfordshire, United Kingdom
| | - Amanda Giddings
- Computational Toxicology, GlaxoSmithKline, Ware, Hertfordshire, United Kingdom
| | - Ehsan Mohammadi
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, 1122 NE 13th Street, Oklahoma City, Oklahoma 73117, United States
| | - Beverly Greenwood-Van Meerveld
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, 1122 NE 13th Street, Oklahoma City, Oklahoma 73117, United States
| | - Allen Oliff
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania 19406, United States
| | - Sanjay Kumar
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania 19406, United States
| | - Mui Cheung
- Virtual Proof of Concept Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania 19406, United States
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Association of VAMP5 and MCC genetic polymorphisms with increased risk of Hirschsprung disease susceptibility in Southern Chinese children. Aging (Albany NY) 2018; 10:689-700. [PMID: 29695640 PMCID: PMC5940112 DOI: 10.18632/aging.101423] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 04/20/2018] [Indexed: 12/12/2022]
Abstract
Hirschsprung disease (HSCR) is a genetic disorder characterized by the absence of neural crest cells in parts of the intestine. This study aims to investigate the association of vesicle-associated membrane protein 5 (VAMP5) and mutated in colorectal cancer (MCC) genetic polymorphisms and their correlated risks with HSCR. We examined the association in four polymorphisms (rs10206961, rs1254900 and rs14242 in VAMP5, rs11241200 in MCC) and HSCR susceptibility in a Southern Chinese population composed of 1473 cases and 1469 controls. Two variants in VAMP5 were replicated as associated with HSCR. Interestingly, we clarified SNPs rs10206961 and rs1254900 in VAMP5 are more essential for patients with long-segment aganglionosis (LHSCR). Relatively high expression correlation was observed between VAMP5 and MCC using data from public database showing there may exist potential genetic interactions. SNP interaction was cross-examined by logistic regression and multifactor dimensionality reduction analysis revealing that VAMP5 rs1254900 and MCC rs11241200 were interacting significantly, thereby contributing to the risk of HSCR. The results suggest that significant associations of the rs10206961 and rs14242 in VAMP5 with an increased risk of HSCR in Southern Chinese, especially in LHSCR patients. This study provided new evidence of epistatic association of VAMP5 and MCC with increased risk of HSCR.
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Peiris M, Hockley JR, Reed DE, Smith ESJ, Bulmer DC, Blackshaw LA. Peripheral K V7 channels regulate visceral sensory function in mouse and human colon. Mol Pain 2018; 13:1744806917709371. [PMID: 28566000 PMCID: PMC5456027 DOI: 10.1177/1744806917709371] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background Chronic visceral pain is a defining symptom of many gastrointestinal disorders. The KV7 family (KV7.1–KV7.5) of voltage-gated potassium channels mediates the M current that regulates excitability in peripheral sensory nociceptors and central pain pathways. Here, we use a combination of immunohistochemistry, gut-nerve electrophysiological recordings in both mouse and human tissues, and single-cell qualitative real-time polymerase chain reaction of gut-projecting sensory neurons, to investigate the contribution of peripheral KV7 channels to visceral nociception. Results Immunohistochemical staining of mouse colon revealed labelling of KV7 subtypes (KV7.3 and KV7.5) with CGRP around intrinsic enteric neurons of the myenteric plexuses and within extrinsic sensory fibres along mesenteric blood vessels. Treatment with the KV7 opener retigabine almost completely abolished visceral afferent firing evoked by the algogen bradykinin, in agreement with significant co-expression of mRNA transcripts by single-cell qualitative real-time polymerase chain reaction for KCNQ subtypes and the B2 bradykinin receptor in retrogradely labelled extrinsic sensory neurons from the colon. Retigabine also attenuated responses to mechanical stimulation of the bowel following noxious distension (0–80 mmHg) in a concentration-dependent manner, whereas the KV7 blocker XE991 potentiated such responses. In human bowel tissues, KV7.3 and KV7.5 were expressed in neuronal varicosities co-labelled with synaptophysin and CGRP, and retigabine inhibited bradykinin-induced afferent activation in afferent recordings from human colon. Conclusions We show that KV7 channels contribute to the sensitivity of visceral sensory neurons to noxious chemical and mechanical stimuli in both mouse and human gut tissues. As such, peripherally restricted KV7 openers may represent a viable therapeutic modality for the treatment of gastrointestinal pathologies.
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Affiliation(s)
- Madusha Peiris
- 1 Centre for Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - James Rf Hockley
- 2 Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - David E Reed
- 3 GI Diseases Research Unit, Queen's University, Kingston, ON, Canada
| | | | - David C Bulmer
- 1 Centre for Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - L Ashley Blackshaw
- 1 Centre for Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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Myers L, Perera H, Alvarado MG, Kidd T. The Drosophila Ret gene functions in the stomatogastric nervous system with the Maverick TGFβ ligand and the Gfrl co-receptor. Development 2018; 145:dev.157446. [PMID: 29361562 DOI: 10.1242/dev.157446] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 12/18/2017] [Indexed: 01/19/2023]
Abstract
The RET receptor tyrosine kinase is crucial for the development of the enteric nervous system (ENS), acting as a receptor for Glial cell line-derived neurotrophic factor (GDNF) via GFR co-receptors. Drosophila has a well-conserved RET homolog (Ret) that has been proposed to function independently of the Gfr-like co-receptor (Gfrl). We find that Ret is required for development of the stomatogastric (enteric) nervous system in both embryos and larvae, and its loss results in feeding defects. Live imaging analysis suggests that peristaltic waves are initiated but not propagated in mutant midguts. Examination of axons innervating the midgut reveals increased branching but the area covered by the branches is decreased. This phenotype can be rescued by Ret expression. Additionally, Gfrl shares the same ENS and feeding defects, suggesting that Ret and Gfrl might function together via a common ligand. We identified the TGFβ family member Maverick (Mav) as a ligand for Gfrl and a Mav chromosomal deficiency displayed similar embryonic ENS defects. Our results suggest that the Ret and Gfrl families co-evolved before the separation of invertebrate and vertebrate lineages.
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Affiliation(s)
- Logan Myers
- Department of Biology/ms 314, University of Nevada, Reno, NV 89557, USA
| | - Hiran Perera
- Department of Biology/ms 314, University of Nevada, Reno, NV 89557, USA
| | | | - Thomas Kidd
- Department of Biology/ms 314, University of Nevada, Reno, NV 89557, USA
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Pu J, Tang S, Tong Q, Wang G, Jia H, Jia Q, Li K, Li D, Yang D, Yang J, Li H, Li S, Mei H. Neuregulin 1 is involved in enteric nervous system development in zebrafish. J Pediatr Surg 2017; 52:1182-1187. [PMID: 28190554 DOI: 10.1016/j.jpedsurg.2017.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 01/12/2017] [Accepted: 01/14/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND Hirschsprung's disease (HD, also known as congenital colon aganglionosis) is a congenital disorder characterized by the absence of intramural ganglion cells in the distal gastrointestinal tract, which results in tonic contraction of the aganglionic gut segment and functional intestinal obstruction. Recent studies have indicated neuregulin 1 (NRG1) as a new candidate gene involved in the development of the enteric nervous system (ENS) in humans. METHODS In our study, we investigated the role of NRG1 in zebrafish ENS development by assessing NRG1 expression patterns during ENS development. Knockdown, overexpression and rescue zebrafish models of NRG1 were created to evaluate differences in phenotype, numbers of enteric neurons, ENS-related factors and nerve fiber arrangements. RESULTS NRG1 was expressed in zebrafish intestine at both the larval and adult stage. We also found that decreased expression of NRG1 resulted in reductions in enteric neuron number and decreased expression of ENS development markers. Moreover, NRG1-knockdown zebrafish exhibited a disordered arrangement of nerve fibers. CONCLUSIONS Collectively, these results demonstrated that NRG1 expression might play a role in zebrafish ENS development. In addition, by modulating NRG1 expression, we created a model that may be useful for investigating the mechanism underlying HD pathogenesis.
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Affiliation(s)
- Jiarui Pu
- Department of Pediatric Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
| | - Shaotao Tang
- Department of Pediatric Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
| | - Qiangsong Tong
- Department of Pediatric Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
| | - Guobin Wang
- Department of Gastrointetinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Haibo Jia
- Department of Biology Science, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Qiong Jia
- Department of Biology Science, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Kang Li
- Department of Pediatric Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Dan Li
- Department of Pediatric Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Dehua Yang
- Department of Pediatric Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jun Yang
- Department of Pediatric Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Hang Li
- Department of Gastrointetinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Shuai Li
- Department of Pediatric Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Hong Mei
- Department of Pediatric Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
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Abstract
Research and clinical experience with vagotomy have confirmed that damage to the central nervous system severely affects physiological movement in the gastrointestinal system. The aim of this study was to investigate the effects of synchronized dual-pulse gastric electrical stimulation (SGES) on the apoptosis of enteric neurons and the possible pathways involved in these effects in vagotomized rats. For this purpose, Male Sprague-Dawley (SD) rats were randomized into a control group, an early subdiaphragmatic vagotomized group (ESDV group), an early subdiaphragmatic vagotomized group with short-term SGES (ESDV + SSGES group), a terminal subdiaphragmatic vagotomized group (TSDV group) and a terminal subdiaphragmatic vagotomized group with long-term SGES (TSDV + LSGES group). The expression levels of connexin 43 (Cx43), glial cell line-derived neurotrophic factor (GDNF), p-Akt, pan-Akt and PGP9.5 were assessed by RT-qPCR, western blot analysis and immunofluorescence staining. Apoptosis was determined by terminal-deoxynucleoitidyl transferase-mediated nick-end labeling (TUNEL) assay. We found that Cx43 expression was decreased in the ESDV and TSDV groups, but was significantly upregulated in the SSGES and LSGES groups. In addition, the GDNF and PGP9.5 expression levels were significantly decreased in the ESDV group compared with the control and TSDV groups and were upregulated in both the SSGES and LSGES groups. The LSGES group exhibited a clear increase in p-Akt expression compared with the TSDV group. Fewer TUNEL-positive cells were observed in the SSGES and LSGES groups than in the ESDV and TSDV groups. More TUNEL-positive cells were found in the stomach of rats subjected to subdiaphragmatic vagotomy. On the whole, our data indicate that SGES improved enteric neuronal survival, possibly through GDNF and the phosphatidylinositol 3-kinase (PI3K)/Akt pathways.
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Affiliation(s)
- Nian Wang
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Kun Li
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Shuangning Song
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Jie Chen
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
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Shin JG, Kim DY, Seo JM, Oh JT, Park KW, Kim HY, Park BL, Kim JH, Shin HD. Potential association of VAMP5 polymorphisms with total colonic aganglionosis in Hirschsprung disease. Neurogastroenterol Motil 2016; 28:1055-63. [PMID: 26970437 DOI: 10.1111/nmo.12807] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/29/2016] [Indexed: 02/08/2023]
Abstract
BACKGROUND Hirschsprung disease (HSCR) is a congenital bowel disease caused by the absence of nerve cells in portions of the intestine. Our recent genome-wide association study has identified a variant (rs1254900) of vesicle-associated membrane protein 5 (VAMP5) as a potential risk locus for total colonic aganglionosis (TCA) in HSCR. In addition, VAMP5 is a member of the VAMP/synaptobrevin protein complex, which participates in nerve signal transduction by regulating the vesicular fusion of the neurotransmitter in synaptic transmission. METHODS A total of 11 single nucleotide polymorphisms (SNPs), including those in the functionally important coding region, were selected on the basis of linkage disequilibrium and genotyped in 187 HSCR patients and 283 unaffected controls by using a TaqMan assay. Logistic analysis was conducted to investigate the possible association between VAMP5 SNPs and the risk of HSCR. KEY RESULTS Genetic variants of VAMP5 showed increased association signals in the TCA subgroup of HSCR patients (minimum p = 9.69 × 10(-5) , OR = 3.93 at rs10206961) compared to other subgroups, even after Bonferroni correction (pcorr = 0.002). In haplotype analysis, three haplotypes (BL1_ht1, BL2_ht1, and BL2_ht2) were associated with the risk of TCA (minimum pcorr = 0.005). In additional combined analysis after imputation based on our previous GWAS, five SNPs still retained significant associations with the TCA subtype (minimum pcorr = 0.006 at rs10206961). CONCLUSIONS & INFERENCES Considering that differential genetic effects on the development of the enteric nervous system, our results suggest that VAMP5 may be associated with the TCA of HSCR. However, further replications and functional evaluations are required.
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Affiliation(s)
- J-G Shin
- Department of Life Science, Sogang University, Seoul, Korea
| | - D-Y Kim
- Department of Pediatric Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - J-M Seo
- Division of Pediatric Surgery, Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - J-T Oh
- Department of Pediatric Surgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - K-W Park
- Department of Pediatric Surgery, Seoul National University Children's Hospital, Seoul, Korea
| | - H-Y Kim
- Department of Pediatric Surgery, Seoul National University Children's Hospital, Seoul, Korea
| | - B L Park
- Department of Genetic Epidemiology, SNP Genetics, Inc., Seoul, Korea
| | - J-H Kim
- Research Institute for Basic Science, Sogang University, Seoul, Korea
| | - H D Shin
- Department of Life Science, Sogang University, Seoul, Korea.,Department of Genetic Epidemiology, SNP Genetics, Inc., Seoul, Korea.,Research Institute for Basic Science, Sogang University, Seoul, Korea
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18
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Xia ZQ, Ding DK, Zhang N, Wang JX, Yang HY, Zhang D. MicroRNA-211 causes ganglion cell dysplasia in congenital intestinal atresia via down-regulation of glial-derived neurotrophic factor. Neurogastroenterol Motil 2016; 28:186-95. [PMID: 26510977 DOI: 10.1111/nmo.12705] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/17/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND MicroRNAs (miRNAs) are known to be involved in normal brain functions and nervous system diseases. Some evidence have pointed to the dysregulation of miRNAs in congenital intestinal atresia. In this study, we investigated the differential expression of miRNAs and the posttranscriptional regulation of glial-derived neurotrophic factor (GDNF) by endogenous miRNA in congenital intestinal atresia. METHODS Quantitative real-time PCR and a Western blot were performed to determine the regulation of miRNA and GDNF in patients with congenital intestinal atresia. The results were verified in rat model of intestinal atresia and bone marrow derived stem cell BMSCs-derived into intestinal ganglion cells. The effects of miRNA and GDNF on the cell proliferation and apoptosis of isolated intestinal ganglion cells were detected with an 3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium (MTT) assay and a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively. KEY RESULTS Only miR-211 was greatly up-regulated in the patients with congenital intestinal atresia. The other miRNAs examined showed no change. Overexpression of miR-211 suppressed the differentiation of BMSCs into intestinal ganglion cells. In retinal ganglion cells (RGC-5 cells), miR-211 regulated the expression of GDNF. The MTT and TUNEL assays revealed that miR-211 overexpression suppressed the cell proliferation of isolated intestinal ganglion cells and that GDNF overexpression reversed the effect of pre-miR-211 on cell proliferation and apoptosis. CONCLUSIONS & INFERENCES Our results indicate that overexpression of miR-211 suppresses the differentiation of BMSCs into intestinal ganglion cells by directly down-regulating the expression of GDNF. The findings elucidate the role of miRNA in congenital intestinal atresia.
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Affiliation(s)
- Z-Q Xia
- Department of Pediatric Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - D-K Ding
- Department of Pediatric Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - N Zhang
- Department of Pediatric Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - J-X Wang
- Department of Pediatric Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - H-Y Yang
- Department of Pediatric Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - D Zhang
- Department of Pediatric Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Du F, Liu S. Electroacupuncture with high frequency at acupoint ST-36 induces regeneration of lost enteric neurons in diabetic rats via GDNF and PI3K/AKT signal pathway. Am J Physiol Regul Integr Comp Physiol 2015; 309:R109-18. [PMID: 25972459 DOI: 10.1152/ajpregu.00396.2014] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 05/08/2015] [Indexed: 12/16/2022]
Abstract
Background electroacupuncture (EA) at acupoint ST-36 (Zusanli) has been used to alleviate gastrointestinal symptoms and improve gastrointestinal motility, but the effects and mechanisms of EA on enteric nervous system (ENS) have scarcely been investigated. SD rats were randomly divided into eight groups: normal control group, diabetes mellitus group (DM), chronic high-frequency EA (C-HEA), chronic low-frequency EA (C-LEA), chronic sham stimulation group (C-SEA), acute high-frequency EA group (A-HEA), acute low-frequency EA group (A-LEA), and diabetic with acute sham stimulation group (A-SEA). The parameters of HEA included a frequency of 100 Hz and an amplitude of 1 mA, while the parameters for LEA were 10 Hz and 1 mA. The expressions of PGP9.5, neuronal nitric oxide synthase neurons, CHAT neurons, glia cell line-derived neurotrophic factor (GDNF) and p-Akt were measured by immunofluorescence or immunohistochemistry, real-time PCR, and Western blotting methods in colon tissues of each rat. The total neurons and the two types of enteric neurons (neuronal nitric oxide synthase and choline acetyl transferase neurons), together with GDNF and p-Akt in the mRNA and protein level were significantly decreased in DM group compared with the normal control group in colon (P < 0.01). Compared with DM or all other DM with EA groups, the chronic HEA could induce a more significant quantitative increase in the mRNA and protein level of the enteric neurons and GDNF and p-Akt in colon (P < 0.01). EA with high-frequency and long-term stimuli at acupoint ST-36 can induce regeneration of lost enteric neurons in diabetic rats, and GDNF and PI3K/Akt signal pathway may play an important role in EA-induced regeneration of impaired enteric neurons.
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Affiliation(s)
- Fan Du
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shi Liu
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Wedel T, Barrenschee M, Lange C, Cossais F, Böttner M. Morphologic Basis for Developing Diverticular Disease, Diverticulitis, and Diverticular Bleeding. VISZERALMEDIZIN 2015; 31:76-82. [PMID: 26989376 PMCID: PMC4789973 DOI: 10.1159/000381431] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Diverticula of the colon are pseudodiverticula defined by multiple outpouchings of the mucosal and submucosal layers penetrating through weak spots of the muscle coat along intramural blood vessels. A complete prolapse consists of a diverticular opening, a narrowed neck, and a thinned diverticular dome underneath the serosal covering. The susceptibility of diverticula to inflammation is explained by local ischemia, translocation of pathogens due to retained stool, stercoral trauma by fecaliths, and microperforations. Local inflammation may lead to phlegmonous diverticulitis, paracolic/mesocolic abscess, bowel perforation, peritonitis, fistula formation, and stenotic strictures. Diverticular bleeding is due to an asymmetric rupture of distended vasa recta at the diverticular dome and not primarily linked to inflammation. Structural and functional changes of the bowel wall in diverticular disease comprise: i) Altered amount, composition, and metabolism of connective tissue; ii) Enteric myopathy with muscular thickening, deranged architecture, and altered myofilament composition; iii) Enteric neuropathy with hypoganglionosis, neurotransmitter imbalance, deficiency of neurotrophic factors and nerve fiber remodeling; and iv) Disturbed intestinal motility both in vivo (increased intraluminal pressure, motility index, high-amplitude propagated contractions) and in vitro (altered spontaneous and pharmacologically triggered contractility). Besides established etiologic factors, recent studies suggest that novel pathophysiologic concepts should be considered in the pathogenesis of diverticular disease.
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Affiliation(s)
- Thilo Wedel
- Institute of Anatomy, Christian-Albrechts-University of Kiel, Kiel, Germany
| | | | - Christina Lange
- Institute of Anatomy, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - François Cossais
- Institute of Anatomy, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Martina Böttner
- Institute of Anatomy, Christian-Albrechts-University of Kiel, Kiel, Germany
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SNAP-25 is abundantly expressed in enteric neuronal networks and upregulated by the neurotrophic factor GDNF. Histochem Cell Biol 2015; 143:611-23. [PMID: 25655772 DOI: 10.1007/s00418-015-1310-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2015] [Indexed: 12/17/2022]
Abstract
Control of intestinal motility requires an intact enteric neurotransmission. Synaptosomal-associated protein 25 (SNAP-25) is an essential component of the synaptic vesicle fusion machinery. The aim of the study was to investigate the localization and expression of SNAP-25 in the human intestine and cultured enteric neurons and to assess its regulation by the neurotrophic factor glial cell line-derived neurotrophic factor (GDNF). SNAP-25 expression and distribution were analyzed in GDNF-stimulated enteric nerve cell cultures, and synaptic vesicles were evaluated by scanning and transmission electron microscopy. Human colonic specimens were processed for site-specific SNAP-25 gene expression analysis and SNAP-25 immunohistochemistry including dual-labeling with the pan-neuronal marker PGP 9.5. Additionally, gene expression levels and distributional patterns of SNAP-25 were analyzed in colonic specimens of patients with diverticular disease (DD). GDNF-treated enteric nerve cell cultures showed abundant expression of SNAP-25 and exhibited granular staining corresponding to synaptic vesicles. SNAP-25 gene expression was detected in all colonic layers and isolated myenteric ganglia. SNAP-25 co-localized with PGP 9.5 in submucosal and myenteric ganglia and intramuscular nerve fibers. In patients with DD, both SNAP-25 mRNA expression and immunoreactive profiles were decreased compared to controls. GDNF-induced growth and differentiation of cultured enteric neurons is paralleled by increased expression of SNAP-25 and formation of synaptic vesicles reflecting enhanced synaptogenesis. The expression of SNAP-25 within the human enteric nervous system and its downregulation in DD suggest an essential role in enteric neurotransmission and render SNAP-25 as a marker for impaired synaptic plasticity in enteric neuropathies underlying intestinal motility disorders.
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