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McKay DM, Defaye M, Rajeev S, MacNaughton WK, Nasser Y, Sharkey KA. Neuroimmunophysiology of the gastrointestinal tract. Am J Physiol Gastrointest Liver Physiol 2024; 326:G712-G725. [PMID: 38626403 DOI: 10.1152/ajpgi.00075.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 04/18/2024]
Abstract
Gut physiology is the epicenter of a web of internal communication systems (i.e., neural, immune, hormonal) mediated by cell-cell contacts, soluble factors, and external influences, such as the microbiome, diet, and the physical environment. Together these provide the signals that shape enteric homeostasis and, when they go awry, lead to disease. Faced with the seemingly paradoxical tasks of nutrient uptake (digestion) and retarding pathogen invasion (host defense), the gut integrates interactions between a variety of cells and signaling molecules to keep the host nourished and protected from pathogens. When the system fails, the outcome can be acute or chronic disease, often labeled as "idiopathic" in nature (e.g., irritable bowel syndrome, inflammatory bowel disease). Here we underscore the importance of a holistic approach to gut physiology, placing an emphasis on intercellular connectedness, using enteric neuroimmunophysiology as the paradigm. The goal of this opinion piece is to acknowledge the pace of change brought to our field via single-cell and -omic methodologies and other techniques such as cell lineage tracing, transgenic animal models, methods for culturing patient tissue, and advanced imaging. We identify gaps in the field and hope to inspire and challenge colleagues to take up the mantle and advance awareness of the subtleties, intricacies, and nuances of intestinal physiology in health and disease by defining communication pathways between gut resident cells, those recruited from the circulation, and "external" influences such as the central nervous system and the gut microbiota.
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Affiliation(s)
- Derek M McKay
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
- Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada
- Inflammation Research Network, University of Calgary, Calgary, Alberta, Canada
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Manon Defaye
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
- Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada
- Inflammation Research Network, University of Calgary, Calgary, Alberta, Canada
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sruthi Rajeev
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
- Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada
- Inflammation Research Network, University of Calgary, Calgary, Alberta, Canada
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Wallace K MacNaughton
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
- Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada
- Inflammation Research Network, University of Calgary, Calgary, Alberta, Canada
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Yasmin Nasser
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
- Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada
- Inflammation Research Network, University of Calgary, Calgary, Alberta, Canada
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Keith A Sharkey
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
- Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
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Li HY, Yan WX, Li J, Ye J, Wu ZG, Hou ZK, Chen B. Global research status and trends of enteric glia: a bibliometric analysis. Front Pharmacol 2024; 15:1403767. [PMID: 38855748 PMCID: PMC11157232 DOI: 10.3389/fphar.2024.1403767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 05/08/2024] [Indexed: 06/11/2024] Open
Abstract
Background Enteric glia are essential components of the enteric nervous system. Previously believed to have a passive structural function, mounting evidence now suggests that these cells are indispensable for maintaining gastrointestinal homeostasis and exert pivotal influences on both wellbeing and pathological conditions. This study aimed to investigate the global status, research hotspots, and future directions of enteric glia. Methods The literature on enteric glia research was acquired from the Web of Science Core Collection. VOSviewer software (v1.6.19) was employed to visually represent co-operation networks among countries, institutions, and authors. The co-occurrence analysis of keywords and co-citation analysis of references were conducted using CiteSpace (v6.1.R6). Simultaneously, cluster analysis and burst detection of keywords and references were performed. Results A total of 514 publications from 36 countries were reviewed. The United States was identified as the most influential country. The top-ranked institutions were University of Nantes and Michigan State University. Michel Neunlist was the most cited author. "Purinergic signaling" was the largest co-cited reference cluster, while "enteric glial cells (EGCs)" was the cluster with the highest number of co-occurring keywords. As the keyword with the highest burst strength, Crohns disease was a hot topic in the early research on enteric glia. The burst detection of keywords revealed that inflammation, intestinal motility, and gut microbiota may be the research frontiers. Conclusion This study provides a comprehensive bibliometric analysis of enteric glia research. EGCs have emerged as a crucial link between neurons and immune cells, attracting significant research attention in neurogastroenterology. Their fundamental and translational studies on inflammation, intestinal motility, and gut microbiota may promote the treatment of some gastrointestinal and parenteral disorders.
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Affiliation(s)
- Huai-Yu Li
- Department of Gastroenterology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Guangdong Clinical Research Academy of Chinese Medicine, Guangzhou, China
| | - Wei-Xin Yan
- Department of Gastroenterology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Guangdong Clinical Research Academy of Chinese Medicine, Guangzhou, China
| | - Jia Li
- The First Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jing Ye
- School of Clinical Medicine, Jiangxi University of Chinese Medicine, Nanchang, China
| | - Zhi-Guo Wu
- Clinical Medical College of Acupuncture, Moxibustion and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zheng-Kun Hou
- Department of Gastroenterology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Guangdong Clinical Research Academy of Chinese Medicine, Guangzhou, China
| | - Bin Chen
- Department of Gastroenterology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Guangdong Clinical Research Academy of Chinese Medicine, Guangzhou, China
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Zhan Y, Wen Y, Zheng F, Du LJ, Chen TY, Shen XL, Wu R, Tang XG. MiR-26b-3p Promotes Intestinal Motility Disorder by Targeting FZD10 to Inhibit GSK3β/β-Catenin Signaling and Induce Enteric Glial Cell Apoptosis. Mol Neurobiol 2024; 61:1543-1561. [PMID: 37728849 DOI: 10.1007/s12035-023-03600-8] [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: 02/08/2023] [Accepted: 08/20/2023] [Indexed: 09/21/2023]
Abstract
Enteric glial cells (EGCs) are the major component of the enteric nervous system and affect the pathophysiological process of intestinal motility dysfunction. MicroRNAs (miRNAs) play an important role in regulating gastrointestinal homeostasis. However, the mechanism of miRNA-mediated regulation of EGCs in intestinal dysmotility remains unclear. In this study, we investigated the effect of EGC apoptosis on intestinal dysmotility, and the effect of miR-26b-3p on EGC proliferation and apoptosis in vivo and in vitro. A loperamide hydrochloride (Lop)-induced constipated mouse model and an in vitro culture system of rat EGCs were established. The transcriptome was used to predict the differentially expressed gene miR-26b-3p and the target gene Frizzled 10 (FZD10), and their targeting binding relationship was verified by luciferase. EGCs were transfected with miR-26b-3p mimic or antagomir, and the FZD10 expression was down-regulated by siRNA. Immunofluorescence and flow cytometry were used to detect EGC apoptosis. MiR-26b-3p and FZD10 expressions were examined using quantitative real-time PCR (qRT-PCR). The CCK-8 assay was used to detect EGC proliferation. The protein levels were detected by Western blotting and enzyme-linked immunosorbent assay (ELISA). The results showed that miR-26b-3p was up-regulated in the Lop group, whereas FZD10 was down-regulated, and EGC apoptosis was increased in the colon of intestinal dysmotility mice. FZD10 down-regulation and miR-26b-3p mimic significantly increased glycogen synthase kinase-3β phosphorylation (p-GSK3β) levels, decreased β-catenin expression, and promoted EGC apoptosis. MiR-26b-3p antagomir alleviated intestinal dysmotility, promoted EGC increased activity of EGCs, and reduced EGC apoptosis in vivo. In conclusion, this study indicated that miR-26b-3p promotes intestinal motility disorders by targeting FZD10 to block GSK3β/β-catenin signaling and induces apoptosis in EGCs. Our results provide a new research target for the treatment and intervention of intestinal dysmotility.
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Affiliation(s)
- Yu Zhan
- Hospital of Chengdu University of TCM, Chengdu, China
- Anorectal Department, Affiliated Hospital of Integrative Chinese Medicine and Western Medicine of Chengdu University of TCM, Chengdu, China
- Chengdu First People's Hospital, Chengdu, China
| | - Yong Wen
- Department of Traditional Chinese Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Fan Zheng
- Anorectal Department, People's Hospital of Deyang City, Deyang, China
- Universiti Sains Malaysia, George Town, Pulau Pinang, Malaysia
| | - Li-Juan Du
- The Third People's Hospital of Chengdu, Chengdu, China
- Southwest Jiaotong University College of Medicine, Chengdu, China
| | - Tai-Yu Chen
- Department of Integrated Traditional and Western Medicine Anorectal, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Xu-Long Shen
- Anorectal Department, Luzhou People's Hospital, Luzhou, China
| | - Rong Wu
- Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xue-Gui Tang
- Department of Integrated Traditional and Western Medicine Anorectal, Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
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Ziegler AL, Caldwell ML, Craig SE, Hellstrom EA, Sheridan AE, Touvron MS, Pridgen TA, Magness ST, Odle J, Van Landeghem L, Blikslager AT. Enteric glial cell network function is required for epithelial barrier restitution following intestinal ischemic injury in the early postnatal period. Am J Physiol Gastrointest Liver Physiol 2024; 326:G228-G246. [PMID: 38147796 PMCID: PMC11211042 DOI: 10.1152/ajpgi.00216.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 08/23/2023] [Accepted: 09/12/2023] [Indexed: 12/28/2023]
Abstract
Ischemic damage to the intestinal epithelial barrier, such as in necrotizing enterocolitis or small intestinal volvulus, is associated with higher mortality rates in younger patients. We have recently reported a powerful pig model to investigate these age-dependent outcomes in which mucosal barrier restitution is strikingly absent in neonates but can be rescued by direct application of homogenized mucosa from older, juvenile pigs by a yet-undefined mechanism. Within the mucosa, a postnatally developing network of enteric glial cells (EGCs) is gaining recognition as a key regulator of the mucosal barrier. Therefore, we hypothesized that the developing EGC network may play an important role in coordinating intestinal barrier repair in neonates. Neonatal and juvenile jejunal mucosa recovering from surgically induced intestinal ischemia was visualized by scanning electron microscopy and the transcriptomic phenotypes were assessed by bulk RNA sequencing. EGC network density and glial activity were examined by Gene Set Enrichment Analysis, three-dimensional (3-D) volume imaging, and Western blot and its function in regulating epithelial restitution was assessed ex vivo in Ussing chamber using the glia-specific inhibitor fluoroacetate (FA), and in vitro by coculture assay. Here we refine and elaborate our translational model, confirming a neonatal phenotype characterized by a complete lack of coordinated reparative signaling in the mucosal microenvironment. Furthermore, we report important evidence that the subepithelial EGC network changes significantly over the early postnatal period and demonstrate that the proximity of a specific functional population of EGC to wounded intestinal epithelium contributes to intestinal barrier restitution following ischemic injury.NEW & NOTEWORTHY This study refines a powerful translational pig model, defining an age-dependent relationship between enteric glia and the intestinal epithelium during intestinal ischemic injury and confirming an important role for enteric glial cell (EGC) activity in driving mucosal barrier restitution. This study suggests that targeting the enteric glial network could lead to novel interventions to improve recovery from intestinal injury in neonatal patients.
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Affiliation(s)
- Amanda L Ziegler
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States
| | - Madison L Caldwell
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States
| | - Sara E Craig
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States
| | - Emily A Hellstrom
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States
| | - Anastasia E Sheridan
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States
| | - Melissa S Touvron
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States
| | - Tiffany A Pridgen
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States
| | - Scott T Magness
- Joint Department of Biomedical Engineering, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States
| | - Jack Odle
- Department of Animal Science, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, North Carolina, United States
| | - Laurianne Van Landeghem
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States
| | - Anthony T Blikslager
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States
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Mao X, Shen J. Potential roles of enteric glial cells in Crohn's disease: A critical review. Cell Prolif 2024; 57:e13536. [PMID: 37551711 PMCID: PMC10771111 DOI: 10.1111/cpr.13536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 07/23/2023] [Accepted: 07/26/2023] [Indexed: 08/09/2023] Open
Abstract
Enteric glial cells in the enteric nervous system are critical for the regulation of gastrointestinal homeostasis. Increasing evidence suggests two-way communication between enteric glial cells and both enteric neurons and immune cells. These interactions may be important in the pathogenesis of Crohn's disease (CD), a chronic relapsing disease characterized by a dysregulated immune response. Structural abnormalities in glial cells have been identified in CD. Furthermore, classical inflammatory pathways associated with CD (e.g., the nuclear factor kappa-B pathway) function in enteric glial cells. However, the specific mechanisms by which enteric glial cells contribute to CD have not been summarized in detail. In this review, we describe the possible roles of enteric glial cells in the pathogenesis of CD, including the roles of glia-immune interactions, neuronal modulation, neural plasticity, and barrier integrity. Additionally, the implications for the development of therapeutic strategies for CD based on enteric glial cell-mediated pathogenic processes are discussed.
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Affiliation(s)
- Xinyi Mao
- Division of Gastroenterology and HepatologyBaoshan Branch, Renji Hospital, School of Medicine, Shanghai Jiao Tong UniversityShanghaiChina
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and HepatologyMinistry of Health, Inflammatory Bowel Disease Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive DiseaseShanghaiChina
| | - Jun Shen
- Division of Gastroenterology and HepatologyBaoshan Branch, Renji Hospital, School of Medicine, Shanghai Jiao Tong UniversityShanghaiChina
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and HepatologyMinistry of Health, Inflammatory Bowel Disease Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive DiseaseShanghaiChina
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Sun A, Hu A, Lin J, Wang L, Xie C, Shi Y, Hong Q, Zhao G. Involvement of iNOS-induced reactive enteric glia cells in gastrointestinal motility disorders of postoperative Ileus mice. J Chem Neuroanat 2023; 133:102312. [PMID: 37459999 DOI: 10.1016/j.jchemneu.2023.102312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/02/2023] [Accepted: 07/14/2023] [Indexed: 09/05/2023]
Abstract
Postoperative ileus (POI) is the cessation or reduction of gastrointestinal (GI) motility after surgery. Reactive enteric glial cells (EGCs) are critical for maintaining bowel function. However, the triggering mechanisms and downstream effects of reactive EGCs in POI were poorly understood. The goal of this current study was to investigate whether the inducible nitric oxide synthase (iNOS)-driven reactive EGCs participated in GI motility disorders and mechanisms underlying altered GI motility in POI. Intestinal manipulation (IM)-induced POI mice and iNOS-/- mice were used in the study. Longitudinal muscle and myenteric plexuses (LMMPs) from the distal small intestine were stained by immunofluorescence. Our results found that the GI motility disorders occurred in the IM-induced POI mice, and reactive EGCs were observed in LMMPs. Glial metabolic inhibitor gliotoxin fluorocitrate (FC) treatment or iNOS gene knockout attenuated GI motility dysfunction. In addition, we also found that FC treatment or iNOS gene knockout significantly inhibited the fluorescence intensity macrophage colony-stimulating factor (M-CSF), which reduced M2 phenotype macrophages activation in LMMPs of IM-induced POI mice. Our findings demonstrated that iNOS-driven reactive EGCs played a key role and were tightly linked to the MMs homeostasis in the POI mice. EGCs are emerging as a new frontier in neurogastroenterology and a potential therapeutic target.
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Affiliation(s)
- Ailing Sun
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province 510000, China
| | - An Hu
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province 510000, China
| | - Jialing Lin
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province 510000, China
| | - Linan Wang
- Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province 510000, China
| | - Chuangbo Xie
- Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province 510000, China
| | - Yongyong Shi
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province 510000, China.
| | - Qingxiong Hong
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province 510000, China.
| | - Gaofeng Zhao
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province 510000, China.
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Mazzotta E, Grants I, Villalobos-Hernandez E, Chaudhuri S, McClain JL, Seguella L, Kendig DM, Blakeney BA, Murthy SK, Schneider R, Leven P, Wehner S, Harzman A, Grider JR, Gulbransen BD, Christofi FL. BQ788 reveals glial ET B receptor modulation of neuronal cholinergic and nitrergic pathways to inhibit intestinal motility: Linked to postoperative ileus. Br J Pharmacol 2023; 180:2550-2576. [PMID: 37198101 PMCID: PMC11085045 DOI: 10.1111/bph.16145] [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: 05/11/2022] [Revised: 05/03/2023] [Accepted: 05/05/2023] [Indexed: 05/19/2023] Open
Abstract
BACKGROUND AND PURPOSE ET-1 signalling modulates intestinal motility and inflammation, but the role of ET-1/ETB receptor signalling is poorly understood. Enteric glia modulate normal motility and inflammation. We investigated whether glial ETB signalling regulates neural-motor pathways of intestinal motility and inflammation. EXPERIMENTAL APPROACH We studied ETB signalling using: ETB drugs (ET-1, SaTX, BQ788), activity-dependent stimulation of neurons (high K+ -depolarization, EFS), gliotoxins, Tg (Ednrb-EGFP)EP59Gsat/Mmucd mice, cell-specific mRNA in Sox10CreERT2 ;Rpl22-HAflx or ChATCre ;Rpl22-HAflx mice, Sox10CreERT2 ::GCaMP5g-tdT, Wnt1Cre2 ::GCaMP5g-tdT mice, muscle tension recordings, fluid-induced peristalsis, ET-1 expression, qPCR, western blots, 3-D LSM-immunofluorescence co-labelling studies in LMMP-CM and a postoperative ileus (POI) model of intestinal inflammation. KEY RESULTS In the muscularis externa ETB receptor is expressed exclusively in glia. ET-1 is expressed in RiboTag (ChAT)-neurons, isolated ganglia and intra-ganglionic varicose-nerve fibres co-labelled with peripherin or SP. ET-1 release provides activity-dependent glial ETB receptor modulation of Ca2+ waves in neural evoked glial responses. BQ788 reveals amplification of glial and neuronal Ca2+ responses and excitatory cholinergic contractions, sensitive to L-NAME. Gliotoxins disrupt SaTX-induced glial-Ca2+ waves and prevent BQ788 amplification of contractions. The ETB receptor is linked to inhibition of contractions and peristalsis. Inflammation causes glial ETB up-regulation, SaTX-hypersensitivity and glial amplification of ETB signalling. In vivo BQ788 (i.p., 1 mg·kg-1 ) attenuates intestinal inflammation in POI. CONCLUSION AND IMPLICATIONS Enteric glial ET-1/ETB signalling provides dual modulation of neural-motor circuits to inhibit motility. It inhibits excitatory cholinergic and stimulates inhibitory nitrergic motor pathways. Amplification of glial ETB receptors is linked to muscularis externa inflammation and possibly pathogenic mechanisms of POI.
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Affiliation(s)
- Elvio Mazzotta
- Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Iveta Grants
- Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | | | - Samhita Chaudhuri
- Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Jonathon L McClain
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Luisa Seguella
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, Rome, Italy
| | - Derek M Kendig
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Bryan A Blakeney
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Srinivasa K Murthy
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | | | - Patrick Leven
- Department of Surgery, University of Bonn, Bonn, Germany
| | - Sven Wehner
- Department of Surgery, University of Bonn, Bonn, Germany
| | - Alan Harzman
- Department of GI Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - John R Grider
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Brian D Gulbransen
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Fedias L Christofi
- Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
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8
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Bubeck M, Becker C, Patankar JV. Guardians of the gut: influence of the enteric nervous system on the intestinal epithelial barrier. Front Med (Lausanne) 2023; 10:1228938. [PMID: 37692784 PMCID: PMC10485265 DOI: 10.3389/fmed.2023.1228938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 07/24/2023] [Indexed: 09/12/2023] Open
Abstract
The intestinal mucosal surface forms one of the largest areas of the body, which is in direct contact with the environment. Co-ordinated sensory functions of immune, epithelial, and neuronal cells ensure the timely detection of noxious queues and potential pathogens and elicit proportional responses to mitigate the threats and maintain homeostasis. Such tuning and maintenance of the epithelial barrier is constantly ongoing during homeostasis and its derangement can become a gateway for systemic consequences. Although efforts in understanding the gatekeeping functions of immune cells have led the way, increasing number of studies point to a crucial role of the enteric nervous system in fine-tuning and maintaining this delicate homeostasis. The identification of immune regulatory functions of enteric neuropeptides and glial-derived factors is still in its infancy, but has already yielded several intriguing insights into their important contribution to the tight control of the mucosal barrier. In this review, we will first introduce the reader to the current understanding of the architecture of the enteric nervous system and the epithelial barrier. Next, we discuss the key discoveries and cellular pathways and mediators that have emerged as links between the enteric nervous, immune, and epithelial systems and how their coordinated actions defend against intestinal infectious and inflammatory diseases. Through this review, the readers will gain a sound understanding of the current neuro-immune-epithelial mechanisms ensuring intestinal barrier integrity and maintenance of intestinal homeostasis.
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Affiliation(s)
- Marvin Bubeck
- Department of Medicine 1, Universitätsklinikum Erlangen, Erlangen, Germany
- Deutsches Zentrum Immuntherapie (DZI), Erlangen, Germany
| | - Christoph Becker
- Department of Medicine 1, Universitätsklinikum Erlangen, Erlangen, Germany
- Deutsches Zentrum Immuntherapie (DZI), Erlangen, Germany
| | - Jay V. Patankar
- Department of Medicine 1, Universitätsklinikum Erlangen, Erlangen, Germany
- Deutsches Zentrum Immuntherapie (DZI), Erlangen, Germany
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Le Berre C, Naveilhan P, Rolli-Derkinderen M. Enteric glia at center stage of inflammatory bowel disease. Neurosci Lett 2023; 809:137315. [PMID: 37257681 DOI: 10.1016/j.neulet.2023.137315] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/02/2023]
Abstract
Although our understanding of the pathophysiology of inflammatory bowel disease (IBD) is increasing, the expanding body of knowledge does not simplify the equation but rather reveals diverse, interconnected, and complex mechanisms in IBD. In addition to immune overactivation, defects in intestinal epithelial barrier (IEB) functioning, dysbiosis, and structural and functional abnormalities of the enteric nervous system are emerging as new elements contributing to the development of IBD. In addition to molecular changes in IBD, enteric glia from patients with Crohn's disease (CD) exhibits the inability to strengthen the IEB; these defects are not observed in patients with ulcerative colitis. In addition, there is a growing body of work describing that enteric glia interacts with not only enterocytes and enteric neurons but also other local cellular neighbours. Thus, because of their functions as connectors and regulators of immune cells, IEB, and microbiota, enteric glia could be the keystone of digestive homeostasis that is lacking in patients with CD.
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Affiliation(s)
- Catherine Le Berre
- Hépato-Gastro-Entérologie et Assistance Nutritionnelle, Inserm CIC 1413, Institut des Maladies de l'Appareil Digestif (IMAD), CHU Nantes, 1 place Alexis Ricordeau, F-44000 Nantes, France; Nantes Université, CHU Nantes, INSERM, The Enteric Nervous System in Gut and Brain Disorders, IMAD, 1 rue Gaston Veil, 44035 Nantes Cedex 1, F-44000 Nantes, France
| | - Philippe Naveilhan
- Nantes Université, CHU Nantes, INSERM, The Enteric Nervous System in Gut and Brain Disorders, IMAD, 1 rue Gaston Veil, 44035 Nantes Cedex 1, F-44000 Nantes, France
| | - Malvyne Rolli-Derkinderen
- Nantes Université, CHU Nantes, INSERM, The Enteric Nervous System in Gut and Brain Disorders, IMAD, 1 rue Gaston Veil, 44035 Nantes Cedex 1, F-44000 Nantes, France.
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10
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Rao IH, Waller EK, Dhamsania RK, Chandrasekaran S. Gene Expression Analysis Links Autocrine Vasoactive Intestinal Peptide and ZEB1 in Gastrointestinal Cancers. Cancers (Basel) 2023; 15:3284. [PMID: 37444395 DOI: 10.3390/cancers15133284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/12/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
VIP (vasoactive intestinal peptide) is a 28-amino acid peptide hormone expressed by cancer and the healthy nervous system, digestive tract, cardiovascular, and immune cell tissues. Many cancers express VIP and its surface receptors VPAC1 and VPAC2, but the role of autocrine VIP signaling in cancer as a targetable prognostic and predictive biomarker remains poorly understood. Therefore, we conducted an in silico gene expression analysis to study the mechanisms of autocrine VIP signaling in cancer. VIP expression from TCGA PANCAN tissue samples was analyzed against the expression levels of 760 cancer-associated genes. Of the 760 genes, 10 (MAPK3, ZEB1, TEK, NOS2, PTCH1 EIF4G1, GMPS, CDK2, RUVBL1, and TIMELESS) showed statistically meaningful associations with the VIP (Pearson's R-coefficient > |0.3|; p < 0.05) across all cancer histologies. The strongest association with the VIP was for the epithelial-mesenchymal transition regulator ZEB1 in gastrointestinal malignancies. Similar positive correlations between the VIP and ZEB1 expression were also observed in healthy gastrointestinal tissues. Gene set analysis indicates the VIP is involved in the EMT and cell cycle pathways, and a high VIP and ZEB1 expression is associated with higher median estimate and stromal scores These findings uncover novel mechanisms for VIP- signaling in cancer and specifically suggest a role for VIP as a biomarker of ZEB1-mediated EMT. Further studies are warranted to characterize the specific mechanism of this interaction.
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Affiliation(s)
- Ishani H Rao
- Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Edmund K Waller
- Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Rohan K Dhamsania
- Philadelphia College of Osteopathic Medicine (PCOM)-Georgia Campus, Suwanee, GA 30024, USA
| | - Sanjay Chandrasekaran
- Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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11
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Prochera A, Rao M. Mini-Review: Enteric glial regulation of the gastrointestinal epithelium. Neurosci Lett 2023; 805:137215. [PMID: 37001854 PMCID: PMC10125724 DOI: 10.1016/j.neulet.2023.137215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/11/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023]
Abstract
Many enteric glia are located along nerve fibers in the gut mucosa where they form close associations with the epithelium lining the gastrointestinal tract. The gut epithelium is essential for absorbing nutrients, regulating fluid flux, forming a physical barrier to prevent the entry of pathogens and toxins into the host, and participating in immune responses. Disruptions to this epithelium are linked to numerous diseases, highlighting its central importance in maintaining health. Accumulating evidence indicates that glia regulate gut epithelial homeostasis. Observations from glial-epithelial co-cultures in vitro and mouse genetic models in vivo suggest that enteric glia influence several important features of the gut epithelium including barrier integrity, ion transport, and capacity for self-renewal. Here we review the evidence for enteric glial regulation of the intestinal epithelium, with a focus on these three features of its biology.
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Affiliation(s)
- Aleksandra Prochera
- Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA; Program in Immunology, Harvard Medical School, Boston, MA, USA
| | - Meenakshi Rao
- Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA.
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12
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Sousa-Soares C, Noronha-Matos JB, Correia-de-Sá P. Purinergic Tuning of the Tripartite Neuromuscular Synapse. Mol Neurobiol 2023; 60:4084-4104. [PMID: 37016047 DOI: 10.1007/s12035-023-03317-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 03/14/2023] [Indexed: 04/06/2023]
Abstract
The vertebrate neuromuscular junction (NMJ) is a specialised chemical synapse involved in the transmission of bioelectric signals between a motor neuron and a skeletal muscle fiber, leading to muscle contraction. Typically, the NMJ is a tripartite synapse comprising (a) a presynaptic region represented by the motor nerve ending, (b) a postsynaptic skeletal motor endplate area, and (c) perisynaptic Schwann cells (PSCs) that shield the motor nerve terminal. Increasing evidence points towards the role of PSCs in the maintenance and control of neuromuscular integrity, transmission, and plasticity. Acetylcholine (ACh) is the main neurotransmitter at the vertebrate skeletal NMJ, and its role is fine-tuned by co-released purinergic neuromodulators, like adenosine 5'-triphosphate (ATP) and its metabolite adenosine (ADO). Adenine nucleotides modulate transmitter release and expression of postsynaptic ACh receptors at motor synapses via the activation of P2Y and P2X receptors. Endogenously generated ADO modulates ACh release by acting via co-localised inhibitory A1 and facilitatory A2A receptors on motor nerve terminals, whose tonic activation depends on the neuronal firing pattern and their interplay with cholinergic receptors and neuropeptides. Thus, the concerted action of adenine nucleotides, ADO, and ACh/neuropeptide co-transmitters is paramount to adapting the neuromuscular transmission to the working load under pathological conditions, like Myasthenia gravis. Unravelling these functional complexities prompted us to review our knowledge about the way purines orchestrate neuromuscular transmission and plasticity in light of the tripartite synapse concept, emphasising the often-forgotten role of PSCs in this context.
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Affiliation(s)
- Carlos Sousa-Soares
- Laboratório de Farmacologia e Neurobiologia, MedInUP, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
- Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - José Bernardo Noronha-Matos
- Laboratório de Farmacologia e Neurobiologia, MedInUP, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
- Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia, MedInUP, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
- Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.
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13
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Chang Y, Wu X, Lu S, Du J, Long Y, Zhu Y, Qin H. Engineered procyanidin-Fe nanoparticle alleviates intestinal inflammation through scavenging ROS and altering gut microbiome in colitis mice. Front Chem 2023; 11:1089775. [PMID: 37065822 PMCID: PMC10090317 DOI: 10.3389/fchem.2023.1089775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 03/21/2023] [Indexed: 03/31/2023] Open
Abstract
Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory bowel disease characterized by inflammation, intestinal barrier injury, and imbalance of gut microbiota. Excess accumulation of reactive oxygen species (ROS) is closely correlated with the development and reoccurrence of IBD. Previous researches demonstrate that procyanidin, as a natural antioxidant, exhibits strong ability of eliminating ROS, thus showing good therapeutic effects in the inflammation-related diseases. Non-etheless, its poor stability and solubility always limits the therapeutic outcomes. Here, we typically designed an antioxidant coordination polymer nanoparticle using the engineering of procyanidin (Pc) and free iron (Fe), named Pc-Fe nanozyme, for effectively scavenging ROS and further inhibiting inflammation while altering the gut microbiome for the treatment of colitis. Furthermore, in vitro experiments uncover that Pc-Fe nanoparticles exert strong multi biomimic activities, including peroxidase, and glutathione peroxidase, for the scavenging of ROS and protecting cells from oxidative injury. In addition, the colon accumulation of Pc-Fe nanozyme effectively protects the intestinal mucosa from oxidative damage while significantly downregulates pro-inflammatory factors, repairs the intestinal barriers and alternates gut microbiome after orally administrated in sodium dextran sulfate (DSS) induced colitis mice. The results collectively illustrate that the multienzyme mimicking Pc-Fe nanozyme owns high potential for treating IBD through scavenging ROS, inhibiting inflammation, repairing gut barriers and alternating gut microbiome, which further promising its clinical translation on IBD treatment and other ROS induced intestinal diseases.
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Affiliation(s)
- Yongliang Chang
- Shanghai Clinical College, Anhui Medical University, Shanghai, China
- The Fifth Clinical Medical College of Anhui Medical University, Hefei, China
- Department of General Surgery, School of Medicine, Shanghai Tenth People’s Hospital Affiliated to Tongji University, Shanghai, China
| | - Xiawei Wu
- Shanghai Clinical College, Anhui Medical University, Shanghai, China
- The Fifth Clinical Medical College of Anhui Medical University, Hefei, China
- Department of General Surgery, School of Medicine, Shanghai Tenth People’s Hospital Affiliated to Tongji University, Shanghai, China
| | - Shengwei Lu
- Shanghai Clinical College, Anhui Medical University, Shanghai, China
- The Fifth Clinical Medical College of Anhui Medical University, Hefei, China
- Department of General Surgery, School of Medicine, Shanghai Tenth People’s Hospital Affiliated to Tongji University, Shanghai, China
| | - Jiahao Du
- Medical School of Nantong University, Nantong, China
| | - Yixiu Long
- Department of Gynecological Oncology, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
- *Correspondence: Yixiu Long, ; Yefei Zhu, ; Huanlong Qin,
| | - Yefei Zhu
- Department of General Surgery, School of Medicine, Shanghai Tenth People’s Hospital Affiliated to Tongji University, Shanghai, China
- *Correspondence: Yixiu Long, ; Yefei Zhu, ; Huanlong Qin,
| | - Huanlong Qin
- Shanghai Clinical College, Anhui Medical University, Shanghai, China
- The Fifth Clinical Medical College of Anhui Medical University, Hefei, China
- Department of General Surgery, School of Medicine, Shanghai Tenth People’s Hospital Affiliated to Tongji University, Shanghai, China
- Medical School of Nantong University, Nantong, China
- *Correspondence: Yixiu Long, ; Yefei Zhu, ; Huanlong Qin,
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14
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Schwann cell functions in peripheral nerve development and repair. Neurobiol Dis 2023; 176:105952. [PMID: 36493976 DOI: 10.1016/j.nbd.2022.105952] [Citation(s) in RCA: 36] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/23/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
The glial cell of the peripheral nervous system (PNS), the Schwann cell (SC), counts among the most multifaceted cells of the body. During development, SCs secure neuronal survival and participate in axonal path finding. Simultaneously, they orchestrate the architectural set up of the developing nerves, including the blood vessels and the endo-, peri- and epineurial layers. Perinatally, in rodents, SCs radially sort and subsequently myelinate individual axons larger than 1 μm in diameter, while small calibre axons become organised in non-myelinating Remak bundles. SCs have a vital role in maintaining axonal health throughout life and several specialized SC types perform essential functions at specific locations, such as terminal SC at the neuromuscular junction (NMJ) or SC within cutaneous sensory end organs. In addition, neural crest derived satellite glia maintain a tight communication with the soma of sensory, sympathetic, and parasympathetic neurons and neural crest derivatives are furthermore an indispensable part of the enteric nervous system. The remarkable plasticity of SCs becomes evident in the context of a nerve injury, where SC transdifferentiate into intriguing repair cells, which orchestrate a regenerative response that promotes nerve repair. Indeed, the multiple adaptations of SCs are captivating, but remain often ill-resolved on the molecular level. Here, we summarize and discuss the knowns and unknowns of the vast array of functions that this single cell type can cover in peripheral nervous system development, maintenance, and repair.
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15
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Channer B, Matt SM, Nickoloff-Bybel EA, Pappa V, Agarwal Y, Wickman J, Gaskill PJ. Dopamine, Immunity, and Disease. Pharmacol Rev 2023; 75:62-158. [PMID: 36757901 PMCID: PMC9832385 DOI: 10.1124/pharmrev.122.000618] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 08/02/2022] [Accepted: 08/04/2022] [Indexed: 12/14/2022] Open
Abstract
The neurotransmitter dopamine is a key factor in central nervous system (CNS) function, regulating many processes including reward, movement, and cognition. Dopamine also regulates critical functions in peripheral organs, such as blood pressure, renal activity, and intestinal motility. Beyond these functions, a growing body of evidence indicates that dopamine is an important immunoregulatory factor. Most types of immune cells express dopamine receptors and other dopaminergic proteins, and many immune cells take up, produce, store, and/or release dopamine, suggesting that dopaminergic immunomodulation is important for immune function. Targeting these pathways could be a promising avenue for the treatment of inflammation and disease, but despite increasing research in this area, data on the specific effects of dopamine on many immune cells and disease processes remain inconsistent and poorly understood. Therefore, this review integrates the current knowledge of the role of dopamine in immune cell function and inflammatory signaling across systems. We also discuss the current understanding of dopaminergic regulation of immune signaling in the CNS and peripheral tissues, highlighting the role of dopaminergic immunomodulation in diseases such as Parkinson's disease, several neuropsychiatric conditions, neurologic human immunodeficiency virus, inflammatory bowel disease, rheumatoid arthritis, and others. Careful consideration is given to the influence of experimental design on results, and we note a number of areas in need of further research. Overall, this review integrates our knowledge of dopaminergic immunology at the cellular, tissue, and disease level and prompts the development of therapeutics and strategies targeted toward ameliorating disease through dopaminergic regulation of immunity. SIGNIFICANCE STATEMENT: Canonically, dopamine is recognized as a neurotransmitter involved in the regulation of movement, cognition, and reward. However, dopamine also acts as an immune modulator in the central nervous system and periphery. This review comprehensively assesses the current knowledge of dopaminergic immunomodulation and the role of dopamine in disease pathogenesis at the cellular and tissue level. This will provide broad access to this information across fields, identify areas in need of further investigation, and drive the development of dopaminergic therapeutic strategies.
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Affiliation(s)
- Breana Channer
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (B.C., S.M.M., E.A.N-B., Y.A., J.W., P.J.G.); and The Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania (V.P.)
| | - Stephanie M Matt
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (B.C., S.M.M., E.A.N-B., Y.A., J.W., P.J.G.); and The Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania (V.P.)
| | - Emily A Nickoloff-Bybel
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (B.C., S.M.M., E.A.N-B., Y.A., J.W., P.J.G.); and The Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania (V.P.)
| | - Vasiliki Pappa
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (B.C., S.M.M., E.A.N-B., Y.A., J.W., P.J.G.); and The Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania (V.P.)
| | - Yash Agarwal
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (B.C., S.M.M., E.A.N-B., Y.A., J.W., P.J.G.); and The Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania (V.P.)
| | - Jason Wickman
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (B.C., S.M.M., E.A.N-B., Y.A., J.W., P.J.G.); and The Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania (V.P.)
| | - Peter J Gaskill
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (B.C., S.M.M., E.A.N-B., Y.A., J.W., P.J.G.); and The Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania (V.P.)
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16
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Unhealthy Diets Induce Distinct and Regional Effects on Intestinal Inflammatory Signalling Pathways and Long-Lasting Metabolic Dysfunction in Rats. Int J Mol Sci 2022; 23:ijms231810984. [PMID: 36142897 PMCID: PMC9503261 DOI: 10.3390/ijms231810984] [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: 07/29/2022] [Revised: 09/09/2022] [Accepted: 09/16/2022] [Indexed: 11/16/2022] Open
Abstract
The intestinal epithelium is a principal site for environmental agents’ detection. Several inflammation- and stress-related signalling pathways have been identified as key players in these processes. However, it is still unclear how the chronic intake of inadequate nutrients triggers inflammatory signalling pathways in different intestinal regions. We aimed to evaluate the impact of unhealthy dietary patterns, starting at a younger age, and the association with metabolic dysfunction, intestinal inflammatory response, and obesity in adulthood. A rat model was used to evaluate the effects of the consumption of sugary beverages (HSD) and a Western diet (WD), composed of ultra-processed foods. Both diets showed a positive correlation with adiposity index, but a positive correlation was found between the HSD diet and the levels of blood glucose and triglycerides, whereas the WD diet correlated positively with triglyceride levels. Moreover, a distinct inflammatory response was associated with either the WD or HSD diets. The WD induced an increase in TLR2, TLR4, and nuclear factor-kappa B (NF-κB) intestinal gene expression, with higher levels in the colon and overexpression of the inducible nitric oxide synthase. In turn, the HSD diet induced activation of the TLR2-mediated NF-κB signalling pathway in the small intestine. Altogether, these findings support the concept that early intake of unhealthy foods and nutrients are a main exogenous signal for disturbances of intestinal immune mechanisms and in a region-specific manner, ultimately leading to obesity-related disorders in later life.
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17
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Li N, Xu J, Gao H, Zhang Y, Li Y, Chang H, Tan S, Li S, Wang Q. Effect of Reactive EGCs on Intestinal Motility and Enteric Neurons During Endotoxemia. J Mol Neurosci 2022; 72:1831-1845. [PMID: 35773377 DOI: 10.1007/s12031-022-02044-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 06/14/2022] [Indexed: 10/17/2022]
Abstract
Paralytic ileus is common in patients with septic shock, causing high morbidity and mortality. Enteric neurons and enteric glial cells (EGCs) regulate intestinal motility. However, little is known about their interaction in endotoxemia. This study aimed to investigate whether reactive EGCs had harmful effects on enteric neurons and participated in intestinal motility disorder in mice during endotoxemia. Endotoxemia was induced by the intraperitoneal injection of lipopolysaccharide (LPS) in mice. Fluorocitrate (FC) was administered before LPS injection to inhibit the reactive EGCs. The effects of reactive EGCs on intestinal motility were analyzed by motility assays in vivo and colonic migrating motor complexes ex vivo. The number of enteric neurons was evaluated by immunofluorescent staining of HuCD, nNOS, and ChAT in vivo. In addition, we stimulated EGCs with IL-1β and TNF-α in vitro and cultured the primary enteric neurons in the conditioned medium, detecting the apoptosis and morphology of neurons through staining TUNEL, cleaved caspase-3 protein, and anti-β-III tubulin. Intestinal motility and peristaltic reflex were improved by inhibiting reactive EGCs in vivo. The density of the neuronal population in the colonic myenteric plexus increased significantly, while the reactive EGCs were inhibited, especially the nitrergic neurons. In vitro, the enteric neurons cultured in the conditioned medium of reactive EGCs had a considerably higher apoptotic rate, less dendritic complexity, and fewer primary neurites. Reactive enteric glial cells probably participated in paralytic ileus by damaging enteric neurons during endotoxemia. They might provide a novel therapeutic strategy for intestinal motility disorders during endotoxemia or sepsis.
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Affiliation(s)
- Na Li
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Jing Xu
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Hui Gao
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Yuxin Zhang
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Yansong Li
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Haiqing Chang
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Shuwen Tan
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Shuang Li
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Qiang Wang
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China.
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18
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Lucarini E, Seguella L, Vincenzi M, Parisio C, Micheli L, Toti A, Corpetti C, Del Re A, Squillace S, Maftei D, Lattanzi R, Ghelardini C, Di Cesare Mannelli L, Esposito G. Role of Enteric Glia as Bridging Element between Gut Inflammation and Visceral Pain Consolidation during Acute Colitis in Rats. Biomedicines 2021; 9:biomedicines9111671. [PMID: 34829900 PMCID: PMC8616000 DOI: 10.3390/biomedicines9111671] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/04/2021] [Accepted: 11/06/2021] [Indexed: 12/30/2022] Open
Abstract
Acute inflammation is particularly relevant in the pathogenesis of visceral hypersensitivity associated with inflammatory bowel diseases. Glia within the enteric nervous system, as well as within the central nervous system, contributes to neuroplasticity during inflammation, but whether enteric glia has the potential to modify visceral sensitivity following colitis is still unknown. This work aimed to investigate the occurrence of changes in the neuron–glial networks controlling visceral perception along the gut–brain axis during colitis, and to assess the effects of peripheral glial manipulation. Enteric glia activity was altered by the poison fluorocitrate (FC; 10 µmol kg−1 i.p.) before inducing colitis in animals (2,4-dinitrobenzenesulfonic acid, DNBS; 30 mg in 0.25 mL EtOH 50%), and visceral sensitivity, colon damage, and glia activation along the pain pathway were studied. FC injection significantly reduced the visceral hyperalgesia, the histological damage, and the immune activation caused by DNBS. Intestinal inflammation is associated with a parallel overexpression of TRPV1 and S100β along the gut–brain axis (colonic myenteric plexuses, dorsal root ganglion, and periaqueductal grey area). This effect was prevented by FC. Peripheral glia activity modulation emerges as a promising strategy for counteracting visceral pain induced by colitis.
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Affiliation(s)
- Elena Lucarini
- Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (E.L.); (C.P.); (L.M.); (A.T.); (C.G.)
| | - Luisa Seguella
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, 00185 Rome, Italy; (L.S.); (M.V.); (C.C.); (A.D.R.); (D.M.); (R.L.); (G.E.)
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
| | - Martina Vincenzi
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, 00185 Rome, Italy; (L.S.); (M.V.); (C.C.); (A.D.R.); (D.M.); (R.L.); (G.E.)
| | - Carmen Parisio
- Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (E.L.); (C.P.); (L.M.); (A.T.); (C.G.)
| | - Laura Micheli
- Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (E.L.); (C.P.); (L.M.); (A.T.); (C.G.)
| | - Alessandra Toti
- Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (E.L.); (C.P.); (L.M.); (A.T.); (C.G.)
| | - Chiara Corpetti
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, 00185 Rome, Italy; (L.S.); (M.V.); (C.C.); (A.D.R.); (D.M.); (R.L.); (G.E.)
| | - Alessandro Del Re
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, 00185 Rome, Italy; (L.S.); (M.V.); (C.C.); (A.D.R.); (D.M.); (R.L.); (G.E.)
| | - Silvia Squillace
- Department of Pharmacology and Physiology and the Henry and Amelia Nasrallah Center for Neuroscience, Saint Louis University School of Medicine, St. Louis, MO 63104, USA;
| | - Daniela Maftei
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, 00185 Rome, Italy; (L.S.); (M.V.); (C.C.); (A.D.R.); (D.M.); (R.L.); (G.E.)
| | - Roberta Lattanzi
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, 00185 Rome, Italy; (L.S.); (M.V.); (C.C.); (A.D.R.); (D.M.); (R.L.); (G.E.)
| | - Carla Ghelardini
- Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (E.L.); (C.P.); (L.M.); (A.T.); (C.G.)
| | - Lorenzo Di Cesare Mannelli
- Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (E.L.); (C.P.); (L.M.); (A.T.); (C.G.)
- Correspondence:
| | - Giuseppe Esposito
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, 00185 Rome, Italy; (L.S.); (M.V.); (C.C.); (A.D.R.); (D.M.); (R.L.); (G.E.)
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19
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High-fat diet impairs duodenal barrier function and elicits glia-dependent changes along the gut-brain axis that are required for anxiogenic and depressive-like behaviors. J Neuroinflammation 2021; 18:115. [PMID: 33993886 PMCID: PMC8126158 DOI: 10.1186/s12974-021-02164-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 04/30/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Mood and metabolic disorders are interrelated and may share common pathological processes. Autonomic neurons link the brain with the gastrointestinal tract and constitute a likely pathway for peripheral metabolic challenges to affect behaviors controlled by the brain. The activities of neurons along these pathways are regulated by glia, which exhibit phenotypic shifts in response to changes in their microenvironment. How glial changes might contribute to the behavioral effects of consuming a high-fat diet (HFD) is uncertain. Here, we tested the hypothesis that anxiogenic and depressive-like behaviors driven by consuming a HFD involve compromised duodenal barrier integrity and subsequent phenotypic changes to glia and neurons along the gut-brain axis. METHODS C57Bl/6 male mice were exposed to a standard diet or HFD for 20 weeks. Bodyweight was monitored weekly and correlated with mucosa histological damage and duodenal expression of tight junction proteins ZO-1 and occludin at 0, 6, and 20 weeks. The expression of GFAP, TLR-4, BDNF, and DCX were investigated in duodenal myenteric plexus, nodose ganglia, and dentate gyrus of the hippocampus at the same time points. Dendritic spine number was measured in cultured neurons isolated from duodenal myenteric plexuses and hippocampi at weeks 0, 6, and 20. Depressive and anxiety behaviors were also assessed by tail suspension, forced swimming, and open field tests. RESULTS HFD mice exhibited duodenal mucosa damage with marked infiltration of immune cells and decreased expression of ZO-1 and occludin that coincided with increasing body weight. Glial expression of GFAP and TLR4 increased in parallel in the duodenal myenteric plexuses, nodose ganglia, and hippocampus in a time-dependent manner. Glial changes were associated with a progressive decrease in BDNF, and DCX expression, fewer neuronal dendritic spines, and anxiogenic/depressive symptoms in HFD-treated mice. Fluorocitrate (FC), a glial metabolic poison, abolished these effects both in the enteric and central nervous systems and prevented behavioral alterations at week 20. CONCLUSIONS HFD impairs duodenal barrier integrity and produces behavioral changes consistent with depressive and anxiety phenotypes. HFD-driven changes in both peripheral and central nervous systems are glial-dependent, suggesting a potential glial role in the alteration of the gut-brain signaling that occurs during metabolic disorders and psychiatric co-morbidity.
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Broadhead MJ, Miles GB. A common role for astrocytes in rhythmic behaviours? Prog Neurobiol 2021; 202:102052. [PMID: 33894330 DOI: 10.1016/j.pneurobio.2021.102052] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 03/03/2021] [Accepted: 04/13/2021] [Indexed: 01/16/2023]
Abstract
Astrocytes are a functionally diverse form of glial cell involved in various aspects of nervous system infrastructure, from the metabolic and structural support of neurons to direct neuromodulation of synaptic activity. Investigating how astrocytes behave in functionally related circuits may help us understand whether there is any conserved logic to the role of astrocytes within neuronal networks. Astrocytes are implicated as key neuromodulatory cells within neural circuits that control a number of rhythmic behaviours such as breathing, locomotion and circadian sleep-wake cycles. In this review, we examine the evidence that astrocytes are directly involved in the regulation of the neural circuits underlying six different rhythmic behaviours: locomotion, breathing, chewing, gastrointestinal motility, circadian sleep-wake cycles and oscillatory feeding behaviour. We discuss how astrocytes are integrated into the neuronal networks that regulate these behaviours, and identify the potential gliotransmission signalling mechanisms involved. From reviewing the evidence of astrocytic involvement in a range of rhythmic behaviours, we reveal a heterogenous array of gliotransmission mechanisms, which help to regulate neuronal networks. However, we also observe an intriguing thread of commonality, in the form of purinergic gliotransmission, which is frequently utilised to facilitate feedback inhibition within rhythmic networks to constrain a given behaviour within its operational range.
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Affiliation(s)
- Matthew J Broadhead
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK.
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
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Meir M, Kannapin F, Diefenbacher M, Ghoreishi Y, Kollmann C, Flemming S, Germer CT, Waschke J, Leven P, Schneider R, Wehner S, Burkard N, Schlegel N. Intestinal Epithelial Barrier Maturation by Enteric Glial Cells Is GDNF-Dependent. Int J Mol Sci 2021; 22:1887. [PMID: 33672854 PMCID: PMC7917776 DOI: 10.3390/ijms22041887] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 12/14/2022] Open
Abstract
Enteric glial cells (EGCs) of the enteric nervous system are critically involved in the maintenance of intestinal epithelial barrier function (IEB). The underlying mechanisms remain undefined. Glial cell line-derived neurotrophic factor (GDNF) contributes to IEB maturation and may therefore be the predominant mediator of this process by EGCs. Using GFAPcre x Ai14floxed mice to isolate EGCs by Fluorescence-activated cell sorting (FACS), we confirmed that they synthesize GDNF in vivo as well as in primary cultures demonstrating that EGCs are a rich source of GDNF in vivo and in vitro. Co-culture of EGCs with Caco2 cells resulted in IEB maturation which was abrogated when GDNF was either depleted from EGC supernatants, or knocked down in EGCs or when the GDNF receptor RET was blocked. Further, TNFα-induced loss of IEB function in Caco2 cells and in organoids was attenuated by EGC supernatants or by recombinant GDNF. These barrier-protective effects were blunted when using supernatants from GDNF-deficient EGCs or by RET receptor blockade. Together, our data show that EGCs produce GDNF to maintain IEB function in vitro through the RET receptor.
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Affiliation(s)
- Michael Meir
- Department of General, Visceral, Vascular and Pediatric Surgery University Hospital Würzburg, Oberduerrbacherstrasse 6, 97080 Wuerzburg, Germany; (M.M.); (F.K.); (Y.G.); (C.K.); (S.F.); (C.-T.G.); (N.B.)
| | - Felix Kannapin
- Department of General, Visceral, Vascular and Pediatric Surgery University Hospital Würzburg, Oberduerrbacherstrasse 6, 97080 Wuerzburg, Germany; (M.M.); (F.K.); (Y.G.); (C.K.); (S.F.); (C.-T.G.); (N.B.)
| | - Markus Diefenbacher
- Department of Biochemistry and Molecular Biochemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany;
| | - Yalda Ghoreishi
- Department of General, Visceral, Vascular and Pediatric Surgery University Hospital Würzburg, Oberduerrbacherstrasse 6, 97080 Wuerzburg, Germany; (M.M.); (F.K.); (Y.G.); (C.K.); (S.F.); (C.-T.G.); (N.B.)
| | - Catherine Kollmann
- Department of General, Visceral, Vascular and Pediatric Surgery University Hospital Würzburg, Oberduerrbacherstrasse 6, 97080 Wuerzburg, Germany; (M.M.); (F.K.); (Y.G.); (C.K.); (S.F.); (C.-T.G.); (N.B.)
| | - Sven Flemming
- Department of General, Visceral, Vascular and Pediatric Surgery University Hospital Würzburg, Oberduerrbacherstrasse 6, 97080 Wuerzburg, Germany; (M.M.); (F.K.); (Y.G.); (C.K.); (S.F.); (C.-T.G.); (N.B.)
| | - Christoph-Thomas Germer
- Department of General, Visceral, Vascular and Pediatric Surgery University Hospital Würzburg, Oberduerrbacherstrasse 6, 97080 Wuerzburg, Germany; (M.M.); (F.K.); (Y.G.); (C.K.); (S.F.); (C.-T.G.); (N.B.)
| | - Jens Waschke
- Department of Anatomy and Cell Biology University of Munich, Pettenkoferstrasse 11, 80336 Munich, Germany;
| | - Patrick Leven
- Department of Surgery, University Clinic Bonn, Venusberg-Campus 1, 53105 Bonn, Germany; (P.L.); (R.S.); (S.W.)
| | - Reiner Schneider
- Department of Surgery, University Clinic Bonn, Venusberg-Campus 1, 53105 Bonn, Germany; (P.L.); (R.S.); (S.W.)
| | - Sven Wehner
- Department of Surgery, University Clinic Bonn, Venusberg-Campus 1, 53105 Bonn, Germany; (P.L.); (R.S.); (S.W.)
| | - Natalie Burkard
- Department of General, Visceral, Vascular and Pediatric Surgery University Hospital Würzburg, Oberduerrbacherstrasse 6, 97080 Wuerzburg, Germany; (M.M.); (F.K.); (Y.G.); (C.K.); (S.F.); (C.-T.G.); (N.B.)
| | - Nicolas Schlegel
- Department of General, Visceral, Vascular and Pediatric Surgery University Hospital Würzburg, Oberduerrbacherstrasse 6, 97080 Wuerzburg, Germany; (M.M.); (F.K.); (Y.G.); (C.K.); (S.F.); (C.-T.G.); (N.B.)
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Enteric Glia at the Crossroads between Intestinal Immune System and Epithelial Barrier: Implications for Parkinson Disease. Int J Mol Sci 2020; 21:ijms21239199. [PMID: 33276665 PMCID: PMC7730281 DOI: 10.3390/ijms21239199] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 11/30/2020] [Accepted: 11/30/2020] [Indexed: 12/15/2022] Open
Abstract
Over recent years, several investigations have suggested that Parkinson’s disease (PD) can be regarded as the consequence of a bowel disorder. Indeed, gastrointestinal symptoms can occur at all stages of this neurodegenerative disease and in up to a third of cases, their onset can precede the involvement of the central nervous system. Recent data suggest that enteric glial cells (EGCs) may play a major role in PD-related gastrointestinal disturbances, as well as in the development and progression of the central disease. In addition to their trophic and structural functions, EGCs are crucial for the homeostatic control of a wide range of gastrointestinal activities. The main purpose of this review was to provide a detailed overview of the role of EGCs in intestinal PD-associated alterations, with particular regard for their participation in digestive and central inflammation as well as the dynamic interactions between glial cells and intestinal epithelial barrier. Accumulating evidence suggests that several pathological intestinal conditions, associated with an impairment of barrier permeability, may trigger dysfunctions of EGCs and their shift towards a proinflammatory phenotype. The reactive gliosis is likely responsible for PD-related neuroinflammation and the associated pathological changes in the ENS. Thus, ameliorating the efficiency of mucosal barrier, as well as avoiding IEB disruption and the related reactive gliosis, might theoretically prevent the onset of PD or, at least, counteract its progression.
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Effects of Colesevelam on Bowel Symptoms, Biomarkers, and Colonic Mucosal Gene Expression in Patients With Bile Acid Diarrhea in a Randomized Trial. Clin Gastroenterol Hepatol 2020; 18:2962-2970.e6. [PMID: 32088296 PMCID: PMC7442687 DOI: 10.1016/j.cgh.2020.02.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 02/04/2020] [Accepted: 02/07/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Approximately one-third of patients with IBS-diarrhea (IBS-D) have increased bile acid (BA) synthesis or excretion. An open-label study showed benefits of colesevelam on bowel functions, consistent with luminal BA sequestration by colesevelam. We compared the effects of colesevelam vs placebo on symptoms and gene expression patterns in the sigmoid colon mucosa in patients with BA diarrhea associated with IBS-D. METHODS We performed a double-blind, parallel-group study of 30 adults with IBS-D and evidence of increased BA synthesis or fecal excretion, from December 2017 through December 2018 at a single center. Patients were randomly assigned (1:1) to groups given colesevelam (3 tablets, 625 mg each) or matching placebo, orally twice daily for 4 weeks. Stool diaries documented bowel functions for 8 days before and 28 days during colesevelam or placebo. Stool and fasting serum samples were collected for analyses of fecal BAs and serum levels of C4 and FGF19. We measured colonic transit by scintigraphy, mucosal permeability by in vivo excretion of saccharide probes, and mRNA levels in rectosigmoid biopsies. All measurements were made at baseline and on the last days of treatment. The primary endpoints were change in total fecal BA concentration and stool consistency. RESULTS Compared with placebo, colesevelam was associated with significant changes in sequestered fecal total BA excretion (P < .001) and serum levels of C4 and FGF19 (both P < .001), and with a mean increase in fecal level of deoxycholic acid (10%; P = .07) compared to placebo. Colesevelam decreased colon mucosal expression of NR1H4 and P2RY4 and increased expression of GPBAR1, compared with baseline. Stool frequency and consistency, colonic transit, and permeability did not differ significantly between groups. Colesevelam was well tolerated. CONCLUSIONS In a randomized trial, we found that colesevelam increases delivery of total and secondary BAs to stool, hepatic BA synthesis, and colonic mucosal expression of genes that regulate BA, farnesoid X, and GPBAR1 receptors. Larger studies are needed to determine the effects on clinical responses. ClinicalTrials.gov no: NCT03270085.
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Fung C, Vanden Berghe P. Functional circuits and signal processing in the enteric nervous system. Cell Mol Life Sci 2020; 77:4505-4522. [PMID: 32424438 PMCID: PMC7599184 DOI: 10.1007/s00018-020-03543-6] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/13/2020] [Accepted: 04/27/2020] [Indexed: 02/06/2023]
Abstract
The enteric nervous system (ENS) is an extensive network comprising millions of neurons and glial cells contained within the wall of the gastrointestinal tract. The major functions of the ENS that have been most studied include the regulation of local gut motility, secretion, and blood flow. Other areas that have been gaining increased attention include its interaction with the immune system, with the gut microbiota and its involvement in the gut-brain axis, and neuro-epithelial interactions. Thus, the enteric circuitry plays a central role in intestinal homeostasis, and this becomes particularly evident when there are faults in its wiring such as in neurodevelopmental or neurodegenerative disorders. In this review, we first focus on the current knowledge on the cellular composition of enteric circuits. We then further discuss how enteric circuits detect and process external information, how these signals may be modulated by physiological and pathophysiological factors, and finally, how outputs are generated for integrated gut function.
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Affiliation(s)
- Candice Fung
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Leuven, Belgium
| | - Pieter Vanden Berghe
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Leuven, Belgium.
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25
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Wang YM, Jia YT, Li ZX. Role of enteric glial cells in intestinal function and intestinal diseases. Shijie Huaren Xiaohua Zazhi 2020; 28:979-985. [DOI: 10.11569/wcjd.v28.i19.979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Enteric glial cells, as a key component of the intestinal nervous system, not only have the function of nutrition and supporting intestinal neurons, but also participate in the regulation of various intestinal functions. Abnormal activation of enteric glial cells may also be one of the important pathogenic factors for inflammatory bowel disease, intestinal infection, intestinal obstruction, colon cancer, and other intestinal diseases. At present, the role of enteric glial cells in the occurrence and development of digestive system diseases remains to be elucidated. This paper reviews the research progress in this area.
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Affiliation(s)
- Ya-Mei Wang
- Graduate School of Hebei Medical University, Shijiazhuang 050017, Hebei Province, China,Department of Oncology, Heibei General Hospital, Shijiazhuang 050051, Hebei Province, China
| | - Yi-Tao Jia
- Department of Oncology, Heibei General Hospital, Shijiazhuang 050051, Hebei Province, China
| | - Zhong-Xin Li
- the Second Department of Surgery, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei Province, China
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26
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Involvement of Enteric Glia in Small Intestine Neuromuscular Dysfunction of Toll-Like Receptor 4-Deficient Mice. Cells 2020; 9:cells9040838. [PMID: 32244316 PMCID: PMC7226836 DOI: 10.3390/cells9040838] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/26/2020] [Accepted: 03/27/2020] [Indexed: 12/16/2022] Open
Abstract
Enteric glial cells (EGCs) influence nitric oxide (NO)− and adenosine diphosphate (ADP)− mediated signaling in the enteric nervous system (ENS). Since Toll-like receptor 4 (TLR4) participates to EGC homoeostasis, this study aimed to evaluate the possible involvement of EGCs in the alterations of the inhibitory neurotransmission in TLR4−/− mice. Ileal segments from male TLR4−/− and wild-type (WT) C57BL/6J mice were incubated with the gliotoxin fluoroacetate (FA). Alterations in ENS morphology and neurochemical coding were investigated by immunohistochemistry whereas neuromuscular responses were determined by recording non-adrenergic non-cholinergic (NANC) relaxations in isometrically suspended isolated ileal preparations. TLR4−/− ileal segments showed increased iNOS immunoreactivity associated with enhanced NANC relaxation, mediated by iNOS-derived NO and sensitive to P2Y1 inhibition. Treatment with FA diminished iNOS immunoreactivity and partially abolished NO− and ADP− mediated relaxation in the TLR4−/− mouse ileum, with no changes of P2Y1 and connexin-43 immunofluorescence distribution in the ENS. After FA treatment, S100β and GFAP immunoreactivity in TLR4−/− myenteric plexus was reduced to levels comparable to those observed in WT. Our findings show the involvement of EGCs in the alterations of ENS architecture and in the increased purinergic and nitrergic-mediated relaxation, determining gut dysmotility in TLR4−/− mice.
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27
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Noronha-Matos JB, Oliveira L, Peixoto AR, Almeida L, Castellão-Santana LM, Ambiel CR, Alves-do Prado W, Correia-de-Sá P. Nicotinic α7 receptor-induced adenosine release from perisynaptic Schwann cells controls acetylcholine spillover from motor endplates. J Neurochem 2020; 154:263-283. [PMID: 32011735 DOI: 10.1111/jnc.14975] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 01/01/2020] [Accepted: 01/30/2020] [Indexed: 12/17/2022]
Abstract
Acetylcholine (ACh) spillover from motor endplates occurs after neuronal firing bursts being potentiated by cholinesterase inhibitors (e.g., neostigmine). Nicotinic α7 receptors (α7nAChR) on perisynaptic Schwann cells (PSCs) can control ACh spillover by unknown mechanisms. We hypothesized that adenosine might be the gliotransmitter underlying PSCs-nerve terminal communication. Rat isolated hemidiaphragm preparations were used to measure (1) the outflow of [3 H]ACh, (2) real-time transmitter exocytosis by video-microscopy with the FM4-64 fluorescent dye, and (3) skeletal muscle contractions during high-frequency (50 Hz) nerve stimulation bursts in the presence of a selective α7nAChR agonist, PNU 282987, or upon inhibition of cholinesterase activity with neostigmine. To confirm our prediction that α7nAChR-mediated effects require direct activation of PSCs, we used fluorescence video-microscopy in the real-time mode to measure PNU 282987-induced [Ca2+ ]i transients from Fluo-4 NW loaded PSCs in non-stimulated preparations. The α7nAChR agonist, PNU 282987, decreased nerve-evoked diaphragm tetanic contractions. PNU 282987-induced inhibition was mimicked by neostigmine and results from the reduction of ACh exocytosis measured as decreases in [3 H]ACh release and FM4-64 fluorescent dye unloading. Methyllycaconitine blockage of α7nAChR and the fluoroacetate gliotoxin both prevented inhibition of nerve-evoked ACh release and PSCs [Ca2+ ]i transients triggered by PNU 282987 and neostigmine. Adenosine deamination, inhibition of the ENT1 nucleoside outflow, and blockage of A1 receptors prevented PNU 282987-induced inhibition of transmitter release. Data suggest that α7nAChR controls tetanic-induced ACh spillover from the neuromuscular synapse by promoting adenosine outflow from PSCs via ENT1 transporters and retrograde activation of presynaptic A1 inhibitory receptors.
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Affiliation(s)
- José B Noronha-Matos
- Laboratório de Farmacologia e Neurobiologia, Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), ICBAS, Universidade do Porto, Porto, Portugal
| | - Laura Oliveira
- Laboratório de Farmacologia e Neurobiologia, Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), ICBAS, Universidade do Porto, Porto, Portugal
| | - Ana R Peixoto
- Laboratório de Farmacologia e Neurobiologia, Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), ICBAS, Universidade do Porto, Porto, Portugal
| | - Liliana Almeida
- Laboratório de Farmacologia e Neurobiologia, Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), ICBAS, Universidade do Porto, Porto, Portugal
| | | | - Célia R Ambiel
- Departamento de Ciências Fisiológicas, Universidade Estadual de Maringá, Paraná, Brazil
| | - Wilson Alves-do Prado
- Departamento de Farmacologia e Terapêutica, Universidade Estadual de Maringá, Paraná, Brazil
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia, Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), ICBAS, Universidade do Porto, Porto, Portugal
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Mohajeri MH, La Fata G, Steinert RE, Weber P. Relationship between the gut microbiome and brain function. Nutr Rev 2019; 76:481-496. [PMID: 29701810 DOI: 10.1093/nutrit/nuy009] [Citation(s) in RCA: 161] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
It has become increasingly evident in recent years that the gut microbiome and the brain communicate in a bidirectional manner, with each possibly affecting the other's functions. Substantial research has aimed to understand the mechanisms of this interaction and to outline strategies for preventing or treating nervous system-related disturbances. This review explores the evidence demonstrating how the gut microbiome may affect brain function in adults, thereby having an impact on stress, anxiety, depression, and cognition. In vitro, in vivo, and human studies reporting an association between a change in the gut microbiome and functional changes in the brain are highlighted, as are studies outlining the mechanisms by which the brain affects the microbiome and the gastrointestinal tract. Possible modes of action to explain how the gut microbiome and the brain functionally affect each other are proposed. Supplemental probiotics to combat brain-related dysfunction offer a promising approach, provided future research elucidates their mode of action and possible side effects. Further studies are warranted to establish how pre- and probiotic interventions may help to balance brain function in healthy and diseased individuals.
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Affiliation(s)
- M Hasan Mohajeri
- Department of Human Nutrition, DSM Nutritional Products, Basel, Switzerland
| | - Giorgio La Fata
- Department of Human Nutrition, DSM Nutritional Products, Basel, Switzerland
| | - Robert E Steinert
- Department of Human Nutrition, DSM Nutritional Products, Basel, Switzerland
| | - Peter Weber
- Department of Human Nutrition, DSM Nutritional Products, Basel, Switzerland
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Region specific differences in the effect of propofol on the murine colon result in dysmotility. Auton Neurosci 2019; 219:19-24. [PMID: 31122597 DOI: 10.1016/j.autneu.2019.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/28/2019] [Accepted: 03/28/2019] [Indexed: 12/19/2022]
Abstract
Propofol is the most widely used intravenous anaesthetic agent for maintenance of anaesthesia and sedation. Studies in varying regions of the bowel have shown conflicting differences on the effects of propofol on motility. There the aim of this study was to understand the influence of propofol on colonic function and explore by which mechanism any changes occur. Functional studies were conducted using isolated colonic tissue from C57BL6 mice which were exposed to 5 μM propofol. Faecal pellet motility, colonic migratory motor complexes (CMMCs) and functional bioassays were utilised to monitor colonic function and nitric oxide production was monitored by amperometry. There was a signficant reduction in amplitude of CMMCs in the distal colon in the presence of 5 μM propofol, however no difference was observed in the proximal colon. A signficant increase in the 5-HT evoked contractions were observed in distal colon in the presence of 5 μM propofol. Additionally, a reduction in the NO production in the presence of 5 μM propofol was only observed in the distal colon. As a result, in the presence of 5 μM propofol, faecal pellet transit was increased, and velocity was reduced. At clinically relevant doses, propofol was shown to reduce colonic motility by inhibiting nitric oxide synthase in only the distal region of the colon. Our findings indicate that propofol has a considerable influence on colonic signalling mechanisms and impairs colonic motility, which may have implications in its clinical use especially for maintenance.
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30
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Grundmann D, Loris E, Maas-Omlor S, Huang W, Scheller A, Kirchhoff F, Schäfer KH. Enteric Glia: S100, GFAP, and Beyond. Anat Rec (Hoboken) 2019; 302:1333-1344. [PMID: 30951262 DOI: 10.1002/ar.24128] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 02/10/2019] [Accepted: 02/18/2019] [Indexed: 12/15/2022]
Abstract
Since several years, the enteric nervous system (ENS) is getting more and more in the focus of gastrointestinal research. While the main interest was credited for years to the enteric neurons and their functional properties, less attention has been paid on the enteric glial cells (EGCs). Although the similarity of EGCs to central nervous system (CNS) astrocytes has been demonstrated a long time ago, EGCs were investigated in more detail only recently. Similar to the CNS, there is not "the" EGC, but also a broad range of diversity. Based on morphology and protein expression, such as glial fibrillary acidic protein (GFAP), S100, or Proteolipid-protein-1 (PLP1), several distinct glial types can be differentiated. Their heterogeneity in morphology, localization, and transcription as well as interaction with surrounding cells indicate versatile functional properties of these cells for gut function in health and disease. Although NG2 is found in a subset of CNS glial cells, it did not colocalize with the glial marker S100 or GFAP in the ENS. Instead, it in part colocalize with PDGFRα, as it does in the CNS, which do stain fibroblast-like cells in the gastrointestinal tract. Moreover, there seem to be species dependent differences. While GFAP is always found in the rodent ENS, this is completely different for the human gut. Only the compromised human ENS shows a significant amount of GFAP-positive glial cells. So, in general we can conclude that the EGC population is species specific and as complex as CNS glia. Anat Rec, 302:1333-1344, 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- David Grundmann
- Department of Biotechnology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Eva Loris
- Department of Biotechnology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Silke Maas-Omlor
- Department of Biotechnology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Wenhui Huang
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Anja Scheller
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Karl-Herbert Schäfer
- Department of Biotechnology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany.,Department of Pediatric Surgery, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
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Vergnolle N, Cirillo C. Neurons and Glia in the Enteric Nervous System and Epithelial Barrier Function. Physiology (Bethesda) 2019; 33:269-280. [PMID: 29897300 DOI: 10.1152/physiol.00009.2018] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The intestinal epithelial barrier is the largest exchange surface between the body and the external environment. Its functions are regulated by luminal, and also internal, components including the enteric nervous system. This review summarizes current knowledge about the role of the digestive "neuronal-glial-epithelial unit" on epithelial barrier function.
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Affiliation(s)
- Nathalie Vergnolle
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse , France.,Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary , Calgary, Alberta , Canada
| | - Carla Cirillo
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse , France.,Laboratory for Enteric Neuroscience, TARGID, University of Leuven , Leuven , Belgium
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5-Fluorouracil Induces Enteric Neuron Death and Glial Activation During Intestinal Mucositis via a S100B-RAGE-NFκB-Dependent Pathway. Sci Rep 2019; 9:665. [PMID: 30679569 PMCID: PMC6345953 DOI: 10.1038/s41598-018-36878-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 11/25/2018] [Indexed: 02/07/2023] Open
Abstract
5-Fluorouracil (5-FU) is an anticancer agent whose main side effects include intestinal mucositis associated with intestinal motility alterations maybe due to an effect on the enteric nervous system (ENS), but the underlying mechanism remains unclear. In this report, we used an animal model to investigate the participation of the S100B/RAGE/NFκB pathway in intestinal mucositis and enteric neurotoxicity caused by 5-FU (450 mg/kg, IP, single dose). 5-FU induced intestinal damage observed by shortened villi, loss of crypt architecture and intense inflammatory cell infiltrate as well as increased GFAP and S100B co-expression and decreased HuC/D protein expression in the small intestine. Furthermore, 5-FU increased RAGE and NFκB NLS immunostaining in enteric neurons, associated with a significant increase in the nitrite/nitrate, IL-6 and TNF-α levels, iNOS expression and MDA accumulation in the small intestine. We provide evidence that 5-FU induces reactive gliosis and reduction of enteric neurons in a S100B/RAGE/NFκB-dependent manner, since pentamidine, a S100B inhibitor, prevented 5-FU-induced neuronal loss, enteric glia activation, intestinal inflammation, oxidative stress and histological injury.
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Sharkey KA, Beck PL, McKay DM. Neuroimmunophysiology of the gut: advances and emerging concepts focusing on the epithelium. Nat Rev Gastroenterol Hepatol 2018; 15:765-784. [PMID: 30069036 DOI: 10.1038/s41575-018-0051-4] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The epithelial lining of the gastrointestinal tract serves as the interface for digestion and absorption of nutrients and water and as a defensive barrier. The defensive functions of the intestinal epithelium are remarkable considering that the gut lumen is home to trillions of resident bacteria, fungi and protozoa (collectively, the intestinal microbiota) that must be prevented from translocation across the epithelial barrier. Imbalances in the relationship between the intestinal microbiota and the host lead to the manifestation of diseases that range from disorders of motility and sensation (IBS) and intestinal inflammation (IBD) to behavioural and metabolic disorders, including autism and obesity. The latest discoveries shed light on the sophisticated intracellular, intercellular and interkingdom signalling mechanisms of host defence that involve epithelial and enteroendocrine cells, the enteric nervous system and the immune system. Together, they maintain homeostasis by integrating luminal signals, including those derived from the microbiota, to regulate the physiology of the gastrointestinal tract in health and disease. Therapeutic strategies are being developed that target these signalling systems to improve the resilience of the gut and treat the symptoms of gastrointestinal disease.
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Affiliation(s)
- Keith A Sharkey
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada. .,Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada. .,Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada. .,Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada.
| | - Paul L Beck
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada.,Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada.,Inflammation Research Network, University of Calgary, Calgary, Alberta, Canada.,Division of Gastroenterology and Hepatology, University of Calgary, Calgary, Alberta, Canada.,Department of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Derek M McKay
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada.,Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Inflammation Research Network, University of Calgary, Calgary, Alberta, Canada
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Morales-Soto W, Gulbransen BD. Enteric Glia: A New Player in Abdominal Pain. Cell Mol Gastroenterol Hepatol 2018; 7:433-445. [PMID: 30739868 PMCID: PMC6369218 DOI: 10.1016/j.jcmgh.2018.11.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/16/2018] [Accepted: 11/19/2018] [Indexed: 12/14/2022]
Abstract
Chronic abdominal pain is the most common gastrointestinal issue and contributes to the pathophysiology of functional bowel disorders and inflammatory bowel disease. Current theories suggest that neuronal plasticity and broad alterations along the brain-gut axis contribute to the development of chronic abdominal pain, but the specific mechanisms involved in chronic abdominal pain remain incompletely understood. Accumulating evidence implicates glial cells in the development and maintenance of chronic pain. Astrocytes and microglia in the central nervous system and satellite glia in dorsal root ganglia contribute to chronic pain states through reactive gliosis, the modification of glial networks, and the synthesis and release of neuromodulators. In addition, new data suggest that enteric glia, a unique type of peripheral glia found within the enteric nervous system, have the potential to modify visceral perception through interactions with neurons and immune cells. Understanding these emerging roles of enteric glia is important to fully understand the mechanisms that drive chronic pain and to identify novel therapeutic targets. In this review, we discuss enteric glial cell signaling mechanisms that have the potential to influence chronic abdominal pain.
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Affiliation(s)
| | - Brian D. Gulbransen
- Correspondence Address correspondence to: Brian D. Gulbransen, PhD, Neuroscience Program and Department of Physiology, Michigan State University, 567 Wilson Road, East Lansing, Michigan 48824. fax: (517) 355-5125.
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MacEachern SJ, Keenan CM, Papakonstantinou E, Sharkey KA, Patel BA. Alterations in melatonin and 5-HT signalling in the colonic mucosa of mice with dextran-sodium sulfate-induced colitis. Br J Pharmacol 2018; 175:1535-1547. [PMID: 29447434 DOI: 10.1111/bph.14163] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 01/16/2018] [Accepted: 02/03/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE Inflammatory bowel disease (IBD) is characterized by pain, bleeding, cramping and altered gastrointestinal (GI) function. Changes in mucosal 5-HT (serotonin) signalling occur in animal models of colitis and in humans suffering from IBD. Melatonin is co-released with 5-HT from the mucosa and has a wide variety of actions in the GI tract. Here, we examined how melatonin signalling is affected by colitis and determined how this relates to 5-HT signalling. EXPERIMENTAL APPROACH Using electroanalytical approaches, we investigated how 5-HT release, reuptake and availability as well as melatonin availability are altered in dextran sodium sulfate (DSS)-induced colitis in mice. Studies were conducted to explore if melatonin treatment during active colitis could reduce the severity of colitis. KEY RESULTS We observed an increase in 5-HT and a decrease in melatonin availability in DSS-induced colitis. A significant reduction in 5-HT reuptake was observed in DSS-induced colitis animals. A reduction in the content of 5-HT was observed, but no difference in tryptophan levels were observed. A reduction in deoxycholic acid-stimulated 5-HT availability and a significant reduction in mechanically-stimulated 5-HT and melatonin availability were observed in DSS-induced colitis. Orally or rectally administered melatonin once colitis was established did not significantly suppress inflammation. CONCLUSION AND IMPLICATIONS Our data suggest that DSS-induced colitis results in a reduction in melatonin availability and an increase in 5-HT availability, due to a reduction/loss of tryptophan hydroxylase 1 enzyme, 5-HT content and 5-HT transporters. Mechanosensory release was more susceptible to inflammation when compared with chemosensory release.
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Affiliation(s)
- Sarah J MacEachern
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada.,Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Catherine M Keenan
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada.,Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | | | - Keith A Sharkey
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada.,Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Bhavik Anil Patel
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building, Brighton, UK.,Centre for Stress and Age-related Diseases, University of Brighton, Huxley Building, Brighton, UK
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36
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Vieira C, Ferreirinha F, Magalhães-Cardoso MT, Silva I, Marques P, Correia-de-Sá P. Post-inflammatory Ileitis Induces Non-neuronal Purinergic Signaling Adjustments of Cholinergic Neurotransmission in the Myenteric Plexus. Front Pharmacol 2017; 8:811. [PMID: 29167643 PMCID: PMC5682326 DOI: 10.3389/fphar.2017.00811] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 10/26/2017] [Indexed: 12/11/2022] Open
Abstract
Uncoupling between ATP overflow and extracellular adenosine formation changes purinergic signaling in post-inflammatory ileitis. Adenosine neuromodulation deficits were ascribed to feed-forward inhibition of ecto-5′-nucleotidase/CD73 by high extracellular adenine nucleotides in the inflamed ileum. Here, we hypothesized that inflammation-induced changes in cellular density may also account to unbalance the release of purines and their influence on [3H]acetylcholine release from longitudinal muscle-myenteric plexus preparations of the ileum of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-treated rats. The population of S100β-positive glial cells increase, whereas Ano-1-positive interstitial cells of Cajal (ICCs) diminished, in the ileum 7-days after the inflammatory insult. In the absence of changes in the density of VAChT-positive cholinergic nerves detected by immunofluorescence confocal microscopy, the inflamed myenteric plexus released smaller amounts of [3H]acetylcholine which also became less sensitive to neuronal blockade by tetrodotoxin (1 μM). Instead, [3H]acetylcholine release was attenuated by sodium fluoroacetate (5 mM), carbenoxolone (10 μM) and A438079 (3 μM), which prevent activation of glial cells, pannexin-1 hemichannels and P2X7 receptors, respectively. Sodium fluoroacetate also decreased ATP overflow without significantly affecting the extracellular adenosine levels, thus indicating that surplus ATP release parallels reactive gliosis in post-inflammatory ileitis. Conversely, loss of ICCs may explain the lower amounts of adenosine detected in TNBS-treated preparations, since blockade of Cav3 (T-type) channels existing in ICCs with mibefradil (3 μM) or inhibition of the equilibrative nucleoside transporter 1 with dipyridamole (0.5 μM), both decreased extracellular adenosine. Data indicate that post-inflammatory ileitis operates a shift on purinergic neuromodulation reflecting the upregulation of ATP-releasing enteric glial cells and the depletion of ICCs accounting for decreased adenosine overflow via equilibrative nucleoside transporters.
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Affiliation(s)
- Cátia Vieira
- Laboratório de Farmacologia e Neurobiologia, Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Fátima Ferreirinha
- Laboratório de Farmacologia e Neurobiologia, Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Maria T Magalhães-Cardoso
- Laboratório de Farmacologia e Neurobiologia, Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Isabel Silva
- Laboratório de Farmacologia e Neurobiologia, Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Patrícia Marques
- Laboratório de Farmacologia e Neurobiologia, Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia, Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
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Fung C, Boesmans W, Cirillo C, Foong JPP, Bornstein JC, Vanden Berghe P. VPAC Receptor Subtypes Tune Purinergic Neuron-to-Glia Communication in the Murine Submucosal Plexus. Front Cell Neurosci 2017; 11:118. [PMID: 28487635 PMCID: PMC5403822 DOI: 10.3389/fncel.2017.00118] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 04/10/2017] [Indexed: 12/20/2022] Open
Abstract
The enteric nervous system (ENS) situated within the gastrointestinal tract comprises an intricate network of neurons and glia which together regulate intestinal function. The exact neuro-glial circuitry and the signaling molecules involved are yet to be fully elucidated. Vasoactive intestinal peptide (VIP) is one of the main neurotransmitters in the gut, and is important for regulating intestinal secretion and motility. However, the role of VIP and its VPAC receptors within the enteric circuitry is not well understood. We investigated this in the submucosal plexus of mouse jejunum using calcium (Ca2+)-imaging. Local VIP application induced Ca2+-transients primarily in neurons and these were inhibited by VPAC1- and VPAC2-antagonists (PG 99-269 and PG 99-465 respectively). These VIP-evoked neural Ca2+-transients were also inhibited by tetrodotoxin (TTX), indicating that they were secondary to action potential generation. Surprisingly, VIP induced Ca2+-transients in glia in the presence of the VPAC2 antagonist. Further, selective VPAC1 receptor activation with the agonist ([K15, R16, L27]VIP(1-7)/GRF(8-27)) predominantly evoked glial responses. However, VPAC1-immunoreactivity did not colocalize with the glial marker glial fibrillary acidic protein (GFAP). Rather, VPAC1 expression was found on cholinergic submucosal neurons and nerve fibers. This suggests that glial responses observed were secondary to neuronal activation. Trains of electrical stimuli were applied to fiber tracts to induce endogenous VIP release. Delayed glial responses were evoked when the VPAC2 antagonist was present. These findings support the presence of an intrinsic VIP/VPAC-initiated neuron-to-glia signaling pathway. VPAC1 agonist-evoked glial responses were inhibited by purinergic antagonists (PPADS and MRS2179), thus demonstrating the involvement of P2Y1 receptors. Collectively, we showed that neurally-released VIP can activate neurons expressing VPAC1 and/or VPAC2 receptors to modulate purine-release onto glia. Selective VPAC1 activation evokes a glial response, whereas VPAC2 receptors may act to inhibit this response. Thus, we identified a component of an enteric neuron-glia circuit that is fine-tuned by endogenous VIP acting through VPAC1- and VPAC2-mediated pathways.
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Affiliation(s)
- Candice Fung
- Department of Physiology, The University of MelbourneParkville, VIC, Australia.,Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU LeuvenLeuven, Belgium
| | - Werend Boesmans
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU LeuvenLeuven, Belgium
| | - Carla Cirillo
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU LeuvenLeuven, Belgium
| | - Jaime P P Foong
- Department of Physiology, The University of MelbourneParkville, VIC, Australia
| | - Joel C Bornstein
- Department of Physiology, The University of MelbourneParkville, VIC, Australia
| | - Pieter Vanden Berghe
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU LeuvenLeuven, Belgium
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38
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Lomax AE, Pradhananga S, Bertrand PP. Plasticity of neuroeffector transmission during bowel inflammation 1. Am J Physiol Gastrointest Liver Physiol 2017; 312:G165-G170. [PMID: 28082285 DOI: 10.1152/ajpgi.00365.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/03/2017] [Accepted: 01/03/2017] [Indexed: 01/31/2023]
Abstract
Altered gastrointestinal (GI) function contributes to the debilitating symptoms of inflammatory bowel diseases (IBD). Nerve circuits contained within the gut wall and outside of the gut play important roles in modulating motility, mucosal fluid transport, and blood flow. The structure and function of these neuronal populations change during IBD. Superimposed on this plasticity is a diminished responsiveness of effector cells - smooth muscle cells, enterocytes, and vascular endothelial cells - to neurotransmitters. The net result is a breakdown in the precisely orchestrated coordination of motility, fluid secretion, and GI blood flow required for health. In this review, we consider how inflammation-induced changes to the effector innervation of these tissues, and changes to the tissues themselves, contribute to defective GI function in models of IBD. We also explore the evidence that reversing neuronal plasticity is sufficient to normalize function during IBD.
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Affiliation(s)
- Alan E Lomax
- Gastrointestinal Disease Research Unit, Queen's University, Kingston, Ontario, Canada; and
| | - Sabindra Pradhananga
- Gastrointestinal Disease Research Unit, Queen's University, Kingston, Ontario, Canada; and
| | - Paul P Bertrand
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Victoria, Australia
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39
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Grubišić V, Gulbransen BD. Enteric glial activity regulates secretomotor function in the mouse colon but does not acutely affect gut permeability. J Physiol 2017; 595:3409-3424. [PMID: 28066889 DOI: 10.1113/jp273492] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 11/30/2016] [Indexed: 12/11/2022] Open
Abstract
KEY POINTS The role of enteric glial cell activity in the acute regulation of epithelial barrier and secretomotor functions of the intestines under physiological conditions is not clear. We used transgenic mice to modify glial activity and found that enteric glia significantly contribute to the neurogenic ion transport while glial activity does not appear to play a major role in the acute regulation of barrier function. The selective activation of glial activity evoked electrogenic ion transport primarily through neural pathways and was sufficient to drive electrogenic ion transport to an extent equal to the direct activation of neurogenic ion transport. These findings provide novel insight into the cellular mechanisms that control fluid transport homeostasis in the intestine and might provide novel therapeutic avenues for functional diarrheal diseases. ABSTRACT Enteric glial cells are often implicated in the regulation of epithelial barrier and secretomotor functions of the intestines. But whether glial cell activity regulates these functions acutely under physiological conditions is not clear. We addressed this issue by using transgenic animal models to modify the activity of enteric glia, either reducing glial expression of connexin 43 in Sox10::CreERT2+/- /Cx43f/f mice or activating glial calcium responses in GFAP::hM3Dq mice, and tested the effects on colonic barrier function and electrogenic ion transport in Ussing chambers. We assessed neuronal-dependent and -independent contributions by activating or inhibiting neurogenic activity with veratridine and tetrodotoxin, respectively. Our results show that the reduction of glial Cx43 expression in Sox10::CreERT2+/- /Cx43f/f mice significantly reduced neurogenic ion transport. The selective glial activation in tissues from GFAP::hM3Dq mice evoked electrogenic ion transport to an extent equal to the direct activation of neurogenic ion transport with veratridine and glial driven responses consisted of both tetrodotoxin-sensitive and -insensitive components. The selective glial stimulation did not affect transmural ion conductance or cell-impermeant dye flux but the baseline ion conductance was more variable in Sox10::CreERT2+/- /Cx43f/f tissues. Together, our findings show that glial activity contributes to the regulation of electrogenic ion transport in the intestine through effects on neurons and possibly direct effects on epithelial cells. However, glial activity does not appear to play a major role in the acute regulation of barrier function. These findings provide novel insight into the cellular mechanisms that control fluid transport homeostasis in the intestine.
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Affiliation(s)
- Vladimir Grubišić
- Neuroscience Program, Department of Physiology, Michigan State University, 567 Wilson Road, East Lansing, MI, 48824, USA
| | - Brian D Gulbransen
- Neuroscience Program, Department of Physiology, Michigan State University, 567 Wilson Road, East Lansing, MI, 48824, USA
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40
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Chow AK, Gulbransen BD. Potential roles of enteric glia in bridging neuroimmune communication in the gut. Am J Physiol Gastrointest Liver Physiol 2017; 312:G145-G152. [PMID: 28039160 PMCID: PMC5338608 DOI: 10.1152/ajpgi.00384.2016] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/18/2016] [Accepted: 12/21/2016] [Indexed: 01/31/2023]
Abstract
The enteric nervous system (ENS) is a network of neurons and glia that controls ongoing gastrointestinal (GI) functions. Damage or injury to the ENS can lead to functional GI disorders. Current data support the conclusion that many functional GI disorders are caused by an imbalance between gut microbes and the immune system, but how the ENS is involved in these interactions is less understood. Because of the proximity of the ENS to bacteria and other foreign antigens in the GI tract, it is important to prevent the passage of these antigens through the GI epithelium. If any foreign compounds manage to pass through the GI epithelium, an immune response is triggered to prevent injury to the ENS and underlying structures. However, careful modulation of the inflammatory response is required to allow for adequate elimination of foreign antigens while avoiding inappropriate overactivation of the immune system as in autoimmune disorders. Enteric neurons and glial cells are capable of performing these immunomodulatory functions to provide adequate protection to the ENS. We review recent studies examining the interactions between the ENS and the immune system, with specific focus on enteric glial cells and their ability to modulate inflammation in the ENS.
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Affiliation(s)
- Aaron K. Chow
- 1Department of Physiology, Michigan State University, East Lansing, Michigan; and
| | - Brian D. Gulbransen
- 1Department of Physiology, Michigan State University, East Lansing, Michigan; and ,2Neuroscience Program, Michigan State University, East Lansing, Michigan
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Grubišić V, Gulbransen BD. Enteric glia: the most alimentary of all glia. J Physiol 2017; 595:557-570. [PMID: 27106597 PMCID: PMC5233670 DOI: 10.1113/jp271021] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 01/06/2016] [Indexed: 12/12/2022] Open
Abstract
Glia (from Greek γλοία meaning 'glue') pertains to non-neuronal cells in the central (CNS) and peripheral nervous system (PNS) that nourish neurons and maintain homeostasis. In addition, glia are now increasingly appreciated as active regulators of numerous physiological processes initially considered exclusively under neuronal regulation. For instance, enteric glia, a collection of glial cells residing within the walls of the intestinal tract, regulate intestinal motility, a well-characterized reflex controlled by enteric neurons. Enteric glia also interact with various non-neuronal cell types in the gut wall such as enterocytes, enteroendocrine and immune cells and are therefore emerging as important local regulators of diverse gut functions. The intricate molecular mechanisms that govern glia-mediated regulation are beginning to be discovered, but much remains unknown about the functions of enteric glia in health and disease. Here we present a current view of the enteric glia and their regulatory roles in gastrointestinal (GI) (patho)physiology; from GI motility and epithelial barrier function to enteric neuroinflammation.
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Affiliation(s)
- Vladimir Grubišić
- Neuroscience Program, Department of PhysiologyMichigan State University567 Wilson RoadEast LansingMI48824USA
| | - Brian D. Gulbransen
- Neuroscience Program, Department of PhysiologyMichigan State University567 Wilson RoadEast LansingMI48824USA
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Spohn SN, Bianco F, Scott RB, Keenan CM, Linton AA, O’Neill CH, Bonora E, Dicay M, Lavoie B, Wilcox RL, MacNaughton WK, De Giorgio R, Sharkey KA, Mawe GM. Protective Actions of Epithelial 5-Hydroxytryptamine 4 Receptors in Normal and Inflamed Colon. Gastroenterology 2016; 151:933-944.e3. [PMID: 27480173 PMCID: PMC5159265 DOI: 10.1053/j.gastro.2016.07.032] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 06/16/2016] [Accepted: 07/06/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS The 5-hydroxytryptamine receptor 4 (5-HT4R or HTR4) is expressed in the colonic epithelium but little is known about its functions there. We examined whether activation of colonic epithelial 5-HT4R protects colons of mice from inflammation. METHODS The 5-HT4R agonist tegaserod (1 mg/kg), the 5-HT4R antagonist GR113808 (1 mg/kg), or vehicle (control) were delivered by enema to wild-type or 5-HT4R knockout mice at the onset of, or during, active colitis, induced by administration of dextran sodium sulfate or trinitrobenzene sulfonic acid. Inflammation was measured using the colitis disease activity index and by histologic analysis of intestinal tissues. Epithelial proliferation, wound healing, and resistance to oxidative stress-induced apoptosis were assessed, as was colonic motility. RESULTS Rectal administration of tegaserod reduced the severity of colitis compared with mice given vehicle, and accelerated recovery from active colitis. Rectal tegaserod did not improve colitis in 5-HT4R knockout mice, and intraperitoneally administered tegaserod did not protect wild-type mice from colitis. Tegaserod increased proliferation of crypt epithelial cells. Stimulation of 5-HT4R increased Caco-2 cell migration and reduced oxidative stress-induced apoptosis; these actions were blocked by co-administration of the 5-HT4R antagonist GR113808. In noninflamed colons of wild-type mice not receiving tegaserod, inhibition of 5-HT4Rs resulted in signs of colitis within 3 days. In these mice, epithelial proliferation decreased and bacterial translocation to the liver and spleen was detected. Daily administration of tegaserod increased motility in inflamed colons of guinea pigs and mice, whereas administration of GR113808 disrupted motility in animals without colitis. CONCLUSIONS 5-HT4R activation maintains motility in healthy colons of mice and guinea pigs, and reduces inflammation in colons of mice with colitis. Agonists might be developed as treatments for patients with inflammatory bowel diseases.
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Affiliation(s)
| | - Francesca Bianco
- Department of Veterinary Medical Sciences,Department of Medical and Surgical Sciences, University of Bologna, Italy
| | | | - Catherine M. Keenan
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada,Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | | | | | - Elena Bonora
- Department of Medical and Surgical Sciences, University of Bologna, Italy
| | - Michael Dicay
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Brigitte Lavoie
- Neurological Sciences, University of Vermont, Burlington, VT
| | | | - Wallace K. MacNaughton
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Roberto De Giorgio
- Department of Medical and Surgical Sciences, University of Bologna, Italy
| | - Keith A. Sharkey
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada,Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Gary M. Mawe
- Neurological Sciences, University of Vermont, Burlington, VT
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McClain JL, Gulbransen BD. The acute inhibition of enteric glial metabolism with fluoroacetate alters calcium signaling, hemichannel function, and the expression of key proteins. J Neurophysiol 2016; 117:365-375. [PMID: 27784805 DOI: 10.1152/jn.00507.2016] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 10/25/2016] [Indexed: 11/22/2022] Open
Abstract
Glia play key roles in the regulation of neurotransmission in the nervous system. Fluoroacetate (FA) is a metabolic poison widely used to study glial functions by disrupting the tricarboxylic acid cycle enzyme aconitase. Despite the widespread use of FA, the effects of FA on essential glial functions such as calcium (Ca2+) signaling and hemichannel function remain unknown. Therefore, our goal was to assess specifically the impact of FA on essential glial cell functions that are involved with neurotransmission in the enteric nervous system. To this end, we generated a new optogenetic mouse model to study specifically the effects of FA on enteric glial Ca2+ signaling by crossing PC::G5-tdTomato mice with Sox10::creERT2 mice. FA did not change the peak glial Ca2+ response when averaged across all glia within a ganglion. However, FA decreased the percent of responding glia by 30% (P < 0.05) and increased the peak Ca2+ response of the glial cells that still exhibited a response by 26% (P < 0.01). Disruption of Ca2+ signaling with FA impaired the activity-dependent uptake of ethidium bromide through connexin-43 (Cx43) hemichannels (P < 0.05) but did not affect baseline Cx43-dependent dye uptake. FA did not cause overt glial or neurodegeneration, but glial cells significantly increased glial fibrillary acid protein by 56% (P < 0.05) following treatment with FA. Together, these data show that the acute impairment of glial metabolism with FA causes key changes in glial functions associated with their roles in neurotransmission and phenotypic changes indicative of reactive gliosis. NEW & NOTEWORTHY Our study shows that the acute impairment of enteric glial metabolism with fluoroacetate (FA) alters specific glial functions that are associated with the modification of neurotransmission in the gut. These include subtle changes to glial agonist-evoked calcium signaling, the subsequent disruption of connexin-43 hemichannels, and changes in protein expression that are consistent with a transition to reactive glia. These changes in glial function offer a mechanistic explanation for the effects of FA on peripheral neuronal networks.
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Affiliation(s)
- Jonathon L McClain
- Department of Physiology, Michigan State University, East Lansing, Michigan; and
| | - Brian D Gulbransen
- Department of Physiology, Michigan State University, East Lansing, Michigan; and .,Neuroscience Program, Michigan State University, East Lansing, Michigan
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Heuckeroth RO, Schäfer KH. Gene-environment interactions and the enteric nervous system: Neural plasticity and Hirschsprung disease prevention. Dev Biol 2016; 417:188-97. [PMID: 26997034 PMCID: PMC5026873 DOI: 10.1016/j.ydbio.2016.03.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/04/2016] [Accepted: 03/14/2016] [Indexed: 12/12/2022]
Abstract
Intestinal function is primarily controlled by an intrinsic nervous system of the bowel called the enteric nervous system (ENS). The cells of the ENS are neural crest derivatives that migrate into and through the bowel during early stages of organogenesis before differentiating into a wide variety of neurons and glia. Although genetic factors critically underlie ENS development, it is now clear that many non-genetic factors may influence the number of enteric neurons, types of enteric neurons, and ratio of neurons to glia. These non-genetic influences include dietary nutrients and medicines that may impact ENS structure and function before or after birth. This review summarizes current data about gene-environment interactions that affect ENS development and suggests that these factors may contribute to human intestinal motility disorders like Hirschsprung disease or irritable bowel syndrome.
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Affiliation(s)
- Robert O Heuckeroth
- Department of Pediatrics, The Children's Hospital of Philadelphia Research Institute, USA; The Perelman School of Medicine at the University of Pennsylvania, Abramson Research Center, 3615 Civic Center Boulevard, Philadelphia, PA 19104, USA.
| | - Karl-Herbert Schäfer
- ENS Group, University of Applied Sciences Kaiserslautern/Zweibrücken, Germany; University of Heidelberg, Paediatric Surgery Mannheim, Germany
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Molecular Signaling and Dysfunction of the Human Reactive Enteric Glial Cell Phenotype: Implications for GI Infection, IBD, POI, Neurological, Motility, and GI Disorders. Inflamm Bowel Dis 2016; 22:1812-34. [PMID: 27416040 PMCID: PMC4993196 DOI: 10.1097/mib.0000000000000854] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Clinical observations or animal studies implicate enteric glial cells in motility disorders, irritable bowel syndrome, inflammatory bowel disease, gastrointestinal (GI) infections, postoperative ileus, and slow transit constipation. Mechanisms underlying glial responses to inflammation in human GI tract are not understood. Our goal was to identify the "reactive human enteric glial cell (rhEGC) phenotype" induced by inflammation, and probe its functional relevance. METHODS Human enteric glial cells in culture from 15 GI-surgical specimens were used to study gene expression, Ca, and purinergic signaling by Ca/fluo-4 imaging and mechanosensitivity. A nanostring panel of 107 genes was designed as a read out of inflammation, transcription, purinergic signaling, vesicular transport protein, channel, antioxidant, and other pathways. A 24-hour treatment with lipopolysaccharide (200 μg/mL) and interferon-γ (10 μg/mL) was used to induce inflammation and study molecular signaling, flow-dependent Ca responses from 3 mL/min to 10 mL/min, adenosine triphosphate (ATP) release, and ATP responses. RESULTS Treatment induced a "rhEGC phenotype" and caused up-regulation in messenger RNA transcripts of 58% of 107 genes analyzed. Regulated genes included inflammatory genes (54%/IP10; IFN-γ; CxCl2; CCL3; CCL2; C3; s100B; IL-1β; IL-2R; TNF-α; IL-4; IL-6; IL-8; IL-10; IL-12A; IL-17A; IL-22; and IL-33), purine-genes (52%/AdoR2A; AdoR2B; P2RY1; P2RY2; P2RY6; P2RX3; P2RX7; AMPD3; ENTPD2; ENTPD3; and NADSYN1), channels (40%/Panx1; CHRNA7; TRPV1; and TRPA1), vesicular transporters (SYT1, SYT2, SNAP25, and SYP), transcription factors (relA/relB, SOCS3, STAT3, GATA_3, and FOXP3), growth factors (IGFBP5 and GMCSF), antioxidant genes (SOD2 and HMOX1), and enzymes (NOS2; TPH2; and CASP3) (P < 0.0001). Treatment disrupted Ca signaling, ATP, and mechanical/flow-dependent Ca responses in human enteric glial cells. ATP release increased 5-fold and s100B decreased 33%. CONCLUSIONS The "rhEGC phenotype" is identified by a complex cascade of pro-inflammatory pathways leading to alterations of important molecular and functional signaling pathways (Ca, purinergic, and mechanosensory) that could disrupt GI motility. Inflammation induced a "purinergic switch" from ATP to adenosine diphosphate/adenosine/uridine triphosphate signaling. Findings have implications for GI infection, inflammatory bowel disease, postoperative ileus, motility, and GI disorders.
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Hashimoto Y, Zumwalt TJ, Goel A. DNA methylation patterns as noninvasive biomarkers and targets of epigenetic therapies in colorectal cancer. Epigenomics 2016; 8:685-703. [PMID: 27102979 DOI: 10.2217/epi-2015-0013] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Aberrant DNA methylation is frequently detected in gastrointestinal tumors, and can therefore potentially be used to screen, diagnose, prognosticate, and predict colorectal cancers (CRCs). Although colonoscopic screening remains the gold standard for CRC screening, this procedure is invasive, expensive, and suffers from poor patient compliance. Methylated DNA is an attractive choice for a biomarker substrate because CRCs harbor hundreds of aberrantly methylated genes. Furthermore, abundance in extracellular environments and resistance to degradation and enrichment in serum, stool, and other noninvasive bodily fluids, allows quantitative measurements of methylated DNA biomarkers. This article describes the most important studies that investigated the efficacy of serum- or stool-derived methylated DNA as population-based screening biomarkers in CRC, details several mechanisms and factors that control DNA methylation, describes a better use of prevailing technologies that discover novel DNA methylation biomarkers, and illustrates the diversity of demethylating agents and their applicability toward clinical impact.
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Affiliation(s)
- Yutaka Hashimoto
- Center for Translational Genomics & Oncology, Baylor Scott & White Research Institute & Sammons Cancer Center, Baylor University Medical Center, Dallas, TX, USA
| | - Timothy J Zumwalt
- Center for Translational Genomics & Oncology, Baylor Scott & White Research Institute & Sammons Cancer Center, Baylor University Medical Center, Dallas, TX, USA
| | - Ajay Goel
- Center for Translational Genomics & Oncology, Baylor Scott & White Research Institute & Sammons Cancer Center, Baylor University Medical Center, Dallas, TX, USA
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Ochoa-Cortes F, Turco F, Linan-Rico A, Soghomonyan S, Whitaker E, Wehner S, Cuomo R, Christofi FL. Enteric Glial Cells: A New Frontier in Neurogastroenterology and Clinical Target for Inflammatory Bowel Diseases. Inflamm Bowel Dis 2016; 22:433-49. [PMID: 26689598 PMCID: PMC4718179 DOI: 10.1097/mib.0000000000000667] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 08/29/2015] [Indexed: 12/12/2022]
Abstract
The word "glia" is derived from the Greek word "γλoια," glue of the enteric nervous system, and for many years, enteric glial cells (EGCs) were believed to provide mainly structural support. However, EGCs as astrocytes in the central nervous system may serve a much more vital and active role in the enteric nervous system, and in homeostatic regulation of gastrointestinal functions. The emphasis of this review will be on emerging concepts supported by basic, translational, and/or clinical studies, implicating EGCs in neuron-to-glial (neuroglial) communication, motility, interactions with other cells in the gut microenvironment, infection, and inflammatory bowel diseases. The concept of the "reactive glial phenotype" is explored as it relates to inflammatory bowel diseases, bacterial and viral infections, postoperative ileus, functional gastrointestinal disorders, and motility disorders. The main theme of this review is that EGCs are emerging as a new frontier in neurogastroenterology and a potential therapeutic target. New technological innovations in neuroimaging techniques are facilitating progress in the field, and an update is provided on exciting new translational studies. Gaps in our knowledge are discussed for further research. Restoring normal EGC function may prove to be an efficient strategy to dampen inflammation. Probiotics, palmitoylethanolamide (peroxisome proliferator-activated receptor-α), interleukin-1 antagonists (anakinra), and interventions acting on nitric oxide, receptor for advanced glycation end products, S100B, or purinergic signaling pathways are relevant clinical targets on EGCs with therapeutic potential.
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Affiliation(s)
| | - Fabio Turco
- Department of Anesthesiology, The Ohio State University, Columbus, Ohio
- Department of Clinical and Experimental Medicine, Gastroenterological Unit, “Federico II” University of Naples, Naples, Italy; and
| | | | - Suren Soghomonyan
- Department of Anesthesiology, The Ohio State University, Columbus, Ohio
| | - Emmett Whitaker
- Department of Anesthesiology, The Ohio State University, Columbus, Ohio
| | - Sven Wehner
- Department of Surgery, University of Bonn, Bonn, Germany
| | - Rosario Cuomo
- Department of Clinical and Experimental Medicine, Gastroenterological Unit, “Federico II” University of Naples, Naples, Italy; and
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Savidge TC. Epigenetic Regulation of Enteric Neurotransmission by Gut Bacteria. Front Cell Neurosci 2016; 9:503. [PMID: 26778967 PMCID: PMC4705220 DOI: 10.3389/fncel.2015.00503] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/14/2015] [Indexed: 12/30/2022] Open
Abstract
The Human Microbiome Project defined microbial community interactions with the human host, and provided important molecular insight into how epigenetic factors can influence intestinal ecosystems. Given physiological context, changes in gut microbial community structure are increasingly found to associate with alterations in enteric neurotransmission and disease. At present, it is not known whether shifts in microbial community dynamics represent cause or consequence of disease pathogenesis. The discovery of bacterial-derived neurotransmitters suggests further studies are needed to establish their role in enteric neuropathy. This mini-review highlights recent advances in bacterial communications to the autonomic nervous system and discusses emerging epigenetic data showing that diet, probiotic and antibiotic use may regulate enteric neurotransmission through modulation of microbial communities. A particular emphasis is placed on bacterial metabolite regulation of enteric nervous system function in the intestine.
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Affiliation(s)
- Tor C Savidge
- Department of Pathology and Immunology, Baylor College of MedicineHouston, TX, USA; Texas Children's Microbiome Center, Texas Children's Children HospitalHouston, TX, USA
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McClain JL, Fried DE, Gulbransen BD. Agonist-evoked Ca 2+ signaling in enteric glia drives neural programs that regulate intestinal motility in mice. Cell Mol Gastroenterol Hepatol 2015; 1:631-645. [PMID: 26693173 PMCID: PMC4673674 DOI: 10.1016/j.jcmgh.2015.08.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 08/14/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Gastrointestinal motility is regulated by enteric neural circuitry that includes enteric neurons and glia. Enteric glia monitor synaptic activity and exhibit responses to neurotransmitters that are encoded by intracellular calcium (Ca2+) signaling. What role evoked glial responses play in the neural regulation of gut motility is unknown. We tested how evoking Ca2+ signaling in enteric glia affects the neural control of intestinal motility. METHODS We used a novel chemogenetic mouse model that expresses the designer receptor hM3Dq under the transcriptional control of the glial fibrillary acidic protein (GFAP) promoter (GFAP::hM3Dq mice) to selectively trigger glial Ca2+ signaling. We used in situ Ca2+ imaging and immunohistochemistry to validate this model and assessed gut motility by measuring pellet output and composition, colonic bead expulsion time, small intestinal transit time, total gut transit time, colonic migrating motor complex (CMMC) recordings and muscle tension recordings. RESULTS hM3Dq receptor expression is confined to GFAP-positive enteric glia in the intestines of GFAP::hM3Dq mice. In these mice, application of the hM3Dq agonist clozapine-N-oxide (CNO) selectively triggers intracellular Ca2+ responses in enteric glia. Glial activation drove neurogenic contractions in the ileum and colon but had no effect on neurogenic relaxations. CNO enhanced the amplitude and frequency of CMMCs in ex vivo preparations of the colon and CNO increased colonic motility in vivo. CNO had no effect on the composition of fecal matter, small intestinal transit or whole gut transit. CONCLUSIONS Glial excitability encoded by intracellular Ca2+ signaling functions to modulate excitatory enteric circuits. Selectively triggering glial Ca2+ signaling might be a novel strategy to improve gut function in motility disorders.
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Affiliation(s)
| | - David E. Fried
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Brian D. Gulbransen
- Department of Physiology, Michigan State University, East Lansing, Michigan
- Neuroscience Program, Michigan State University, East Lansing, Michigan
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