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Abstract
Glia, the non-neuronal cells of the nervous system, were long considered secondary cells only necessary for supporting the functions of their more important neuronal neighbors. Work by many groups over the past two decades has completely overturned this notion, revealing the myriad and vital functions of glia in nervous system development, plasticity, and health. The largest population of glia outside the brain is in the enteric nervous system, a division of the autonomic nervous system that constitutes a key node of the gut-brain axis. Here, we review the latest in the understanding of these enteric glia in mammals with a focus on their putative roles in human health and disease.
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Affiliation(s)
- Harry J. Rosenberg
- Department of Pathology, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
- Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Meenakshi Rao
- Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
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Seguella L, Gulbransen BD. Enteric glial biology, intercellular signalling and roles in gastrointestinal disease. Nat Rev Gastroenterol Hepatol 2021; 18:571-587. [PMID: 33731961 PMCID: PMC8324524 DOI: 10.1038/s41575-021-00423-7] [Citation(s) in RCA: 130] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/28/2021] [Indexed: 02/07/2023]
Abstract
One of the most transformative developments in neurogastroenterology is the realization that many functions normally attributed to enteric neurons involve interactions with enteric glial cells: a large population of peripheral neuroglia associated with enteric neurons throughout the gastrointestinal tract. The notion that glial cells function solely as passive support cells has been refuted by compelling evidence that demonstrates that enteric glia are important homeostatic cells of the intestine. Active signalling mechanisms between enteric glia and neurons modulate gastrointestinal reflexes and, in certain circumstances, function to drive neuroinflammatory processes that lead to long-term dysfunction. Bidirectional communication between enteric glia and immune cells contributes to gastrointestinal immune homeostasis, and crosstalk between enteric glia and cancer stem cells regulates tumorigenesis. These neuromodulatory and immunomodulatory roles place enteric glia in a unique position to regulate diverse gastrointestinal disease processes. In this Review, we discuss current concepts regarding enteric glial development, heterogeneity and functional roles in gastrointestinal pathophysiology and pathophysiology, with a focus on interactions with neurons and immune cells. We also present a working model to differentiate glial states based on normal function and disease-induced dysfunctions.
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Affiliation(s)
- Luisa Seguella
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, Rome, Italy
- Department of Physiology, Neuroscience Program, Michigan State University, East Lansing, MI, USA
| | - Brian D Gulbransen
- Department of Physiology, Neuroscience Program, Michigan State University, East Lansing, MI, USA.
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Seguella L, Capuano R, Sarnelli G, Esposito G. Play in advance against neurodegeneration: exploring enteric glial cells in gut-brain axis during neurodegenerative diseases. Expert Rev Clin Pharmacol 2019; 12:555-564. [PMID: 31025582 DOI: 10.1080/17512433.2019.1612744] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Introduction: New investigations have shown that 'activated' enteric glial cells (EGCs), astrocyte-like cells of the enteric nervous system (ENS), represent a possible extra-CNS trigger point of the neurodegenerative processes in impaired intestinal permeability conditions. The early modulation of enteric glia-mediated neuroinflammation might optimize neuroprotective treatments outcomes currently used in neurodegenerative diseases. Areas covered: We discussed recent clinical and preclinical data existing on the Pubmed database, concerning the glial role in neurodegeneration. We focused on the gut as possible "entrance door" for endoluminal neurotoxic agents that induce neurological impairments during leaky gut conditions. Moreover, we reviewed the paradigmatic studies linking the leaky gut-induced priming of EGCs to the induction of late neurodegenerative processes in Parkinson's disease and other neurodegenerative disorders. Expert opinion: The previous appearance of neuropathological markers in the ENS emphasizes the extra-CNS origin of neurodegenerative disorders, by directing their therapies toward peripheral management of neurodegeneration. In light of the EGCs changes resulting from a switch-on of activated phenotype in leaky gut syndrome, EGCs sampling could be predictive for neuropathological conditions detection, anticipating their symptomatic manifestation in the CNS.
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Affiliation(s)
- Luisa Seguella
- a Department of Physiology and Pharmacology "V. Erspamer" , Sapienza University of Rome , Rome , Italy
| | - Riccardo Capuano
- a Department of Physiology and Pharmacology "V. Erspamer" , Sapienza University of Rome , Rome , Italy
| | - Giovanni Sarnelli
- b Department of Clinical Medicine and Surgery , University of Naples 'Federico II' , Naples , Italy
| | - Giuseppe Esposito
- a Department of Physiology and Pharmacology "V. Erspamer" , Sapienza University of Rome , Rome , Italy
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Abstract
The interplay between the immune and nervous systems has been acknowledged in the past, but only more recent studies have started to unravel the cellular and molecular players of such interactions. Mounting evidence indicates that environmental signals are sensed by discrete neuro-immune cell units (NICUs), which represent defined anatomical locations in which immune and neuronal cells colocalize and functionally interact to steer tissue physiology and protection. These units have now been described in multiple tissues throughout the body, including lymphoid organs, adipose tissue, and mucosal barriers. As such, NICUs are emerging as important orchestrators of multiple physiological processes, including hematopoiesis, organogenesis, inflammation, tissue repair, and thermogenesis. In this review we focus on the impact of NICUs in tissue physiology and how this fast-evolving field is driving a paradigm shift in our understanding of immunoregulation and organismal physiology.
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Affiliation(s)
- Cristina Godinho-Silva
- Champalimaud Research, Champalimaud Centre for the Unknown, 1400-038 Lisboa, Portugal; , ,
| | - Filipa Cardoso
- Champalimaud Research, Champalimaud Centre for the Unknown, 1400-038 Lisboa, Portugal; , ,
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Chida J, Hara H, Yano M, Uchiyama K, Das NR, Takahashi E, Miyata H, Tomioka Y, Ito T, Kido H, Sakaguchi S. Prion protein protects mice from lethal infection with influenza A viruses. PLoS Pathog 2018; 14:e1007049. [PMID: 29723291 PMCID: PMC5953499 DOI: 10.1371/journal.ppat.1007049] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 05/15/2018] [Accepted: 04/23/2018] [Indexed: 11/18/2022] Open
Abstract
The cellular prion protein, designated PrPC, is a membrane glycoprotein expressed abundantly in brains and to a lesser extent in other tissues. Conformational conversion of PrPC into the amyloidogenic isoform is a key pathogenic event in prion diseases. However, the physiological functions of PrPC remain largely unknown, particularly in non-neuronal tissues. Here, we show that PrPC is expressed in lung epithelial cells, including alveolar type 1 and 2 cells and bronchiolar Clara cells. Compared with wild-type (WT) mice, PrPC-null mice (Prnp0/0) were highly susceptible to influenza A viruses (IAVs), with higher mortality. Infected Prnp0/0 lungs were severely injured, with higher inflammation and higher apoptosis of epithelial cells, and contained higher reactive oxygen species (ROS) than control WT lungs. Treatment with a ROS scavenger or an inhibitor of xanthine oxidase (XO), a major ROS-generating enzyme in IAV-infected lungs, rescued Prnp0/0 mice from the lethal infection with IAV. Moreover, Prnp0/0 mice transgenic for PrP with a deletion of the Cu-binding octapeptide repeat (OR) region, Tg(PrPΔOR)/Prnp0/0 mice, were also highly susceptible to IAV infection. These results indicate that PrPC has a protective role against lethal infection with IAVs through the Cu-binding OR region by reducing ROS in infected lungs. Cu content and the activity of anti-oxidant enzyme Cu/Zn-dependent superoxide dismutase, SOD1, were lower in Prnp0/0 and Tg(PrPΔOR)/Prnp0/0 lungs than in WT lungs. It is thus conceivable that PrPC functions to maintain Cu content and regulate SOD1 through the OR region in lungs, thereby reducing ROS in IAV-infected lungs and eventually protecting them from lethal infection with IAVs. Our current results highlight the role of PrPC in protection against IAV infection, and suggest that PrPC might be a novel target molecule for anti-influenza therapeutics. Influenza A virus (IAV) is an enveloped, negative sense, single-stranded RNA virus, causing seasonal epidemic outbreaks of influenza. Anti-influenza agents targeting viral molecules, such as neuraminidase inhibitors, are currently available. However, these agents have accelerated emergence of mutant IAVs that are resistant to these agents among human populations. Development of new types of anti-influenza agents is awaited. We show that the cellular prion protein PrPC has a protective role against lethal infection with IAVs through the octapeptide repeat (OR) region by abrogating lung epithelial cell apoptosis induced by reactive oxygen species (ROS) in infected lungs. We also show that PrPC could reduce ROS in IAV-infected lungs through the OR region by maintaining Cu ion homeostasis and thereby activating Cu/Zn-dependent superoxide dismutase, SOD1. These results highlight the protective role of PrPC in IAV infection. Elucidation of the exact mechanism underlying the PrPC-mediated protection against IAV infection would be important for further understanding the pathogenesis of IAV infection and could be useful for development of new types of anti-influenza therapeutics.
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Affiliation(s)
- Junji Chida
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Hideyuki Hara
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Masashi Yano
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Keiji Uchiyama
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Nandita Rani Das
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Etsuhisa Takahashi
- Division of Enzyme Chemistry, Institute for Enzyme Research, Tokushima University, Tokushima, Japan
| | - Hironori Miyata
- Animal Research Center, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Yukiko Tomioka
- Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Koyama-cho, Tottori, Japan
| | - Toshihiro Ito
- Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Koyama-cho, Tottori, Japan
| | - Hiroshi Kido
- Division of Enzyme Chemistry, Institute for Enzyme Research, Tokushima University, Tokushima, Japan
| | - Suehiro Sakaguchi
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
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Lerner A, Neidhöfer S, Matthias T. The Gut Microbiome Feelings of the Brain: A Perspective for Non-Microbiologists. Microorganisms 2017; 5:E66. [PMID: 29023380 PMCID: PMC5748575 DOI: 10.3390/microorganisms5040066] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 09/28/2017] [Accepted: 10/09/2017] [Indexed: 02/06/2023] Open
Abstract
Objectives: To comprehensively review the scientific knowledge on the gut-brain axis. Methods: Various publications on the gut-brain axis, until 31 July 2017, were screened using the Medline, Google, and Cochrane Library databases. The search was performed using the following keywords: "gut-brain axis", "gut-microbiota-brain axis", "nutrition microbiome/microbiota", "enteric nervous system", "enteric glial cells/network", "gut-brain pathways", "microbiome immune system", "microbiome neuroendocrine system" and "intestinal/gut/enteric neuropeptides". Relevant articles were selected and reviewed. Results: Tremendous progress has been made in exploring the interactions between nutrients, the microbiome, and the intestinal, epithelium-enteric nervous, endocrine and immune systems and the brain. The basis of the gut-brain axis comprises of an array of multichannel sensing and trafficking pathways that are suggested to convey the enteric signals to the brain. These are mediated by neuroanatomy (represented by the vagal and spinal afferent neurons), the neuroendocrine-hypothalamic-pituitary-adrenal (HPA) axis (represented by the gut hormones), immune routes (represented by multiple cytokines), microbially-derived neurotransmitters, and finally the gate keepers of the intestinal and brain barriers. Their mutual and harmonious but intricate interaction is essential for human life and brain performance. However, a failure in the interaction leads to a number of inflammatory-, autoimmune-, neurodegenerative-, metabolic-, mood-, behavioral-, cognitive-, autism-spectrum-, stress- and pain-related disorders. The limited availability of information on the mechanisms, pathways and cause-and-effect relationships hinders us from translating and implementing the knowledge from the bench to the clinic. Implications: Further understanding of this intricate field might potentially shed light on novel preventive and therapeutic strategies to combat these disorders. Nutritional approaches, microbiome manipulations, enteric and brain barrier reinforcement and sensing and trafficking modulation might improve physical and mental health outcomes.
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Affiliation(s)
- Aaron Lerner
- B. Rappaport School of Medicine, Technion-Israel Institute of Technology, Bat Galim, Haifa 3200003, Israel.
- AESKU.KIPP Institute, Mikroforum Ring 2, 55234 Wendelsheim, Germany.
| | - Sandra Neidhöfer
- AESKU.KIPP Institute, Mikroforum Ring 2, 55234 Wendelsheim, Germany.
| | - Torsten Matthias
- AESKU.KIPP Institute, Mikroforum Ring 2, 55234 Wendelsheim, Germany.
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Ellett LJ, Lawson VA. Preparation and Immunostaining of the Myenteric Plexus of Prion-Infected Mice. Methods Mol Biol 2017; 1658:285-292. [PMID: 28861796 DOI: 10.1007/978-1-4939-7244-9_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Intracerebral inoculation of mice with the M1000 strain of mouse-adapted human prions results in the consistent accumulation of PrPSc in the ileum of the gastrointestinal tract (GIT) of mice with clinical signs of prion disease. The accumulation of PrPSc in the ileum is accompanied by caspase activation and loss of immunoreactivity in subpopulations of neurons in the enteric nervous system. This suggests that like neurons in the central nervous system, cells in the enteric nervous system are also susceptible to prion-induced toxicity. In this chapter we describe the immunostaining of cells in myenteric plexus preparations of whole mounts prepared from the gastrointestinal tract of prion-infected mice.
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Affiliation(s)
- Laura J Ellett
- Department of Pathology, The University of Melbourne, Medical Building, Parkville, VIC, 3010, Australia
| | - Victoria A Lawson
- Department of Pathology, The University of Melbourne, Medical Building, Parkville, VIC, 3010, Australia.
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Rao M, Gershon MD. The bowel and beyond: the enteric nervous system in neurological disorders. Nat Rev Gastroenterol Hepatol 2016; 13:517-28. [PMID: 27435372 PMCID: PMC5005185 DOI: 10.1038/nrgastro.2016.107] [Citation(s) in RCA: 355] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The enteric nervous system (ENS) is large, complex and uniquely able to orchestrate gastrointestinal behaviour independently of the central nervous system (CNS). An intact ENS is essential for life and ENS dysfunction is often linked to digestive disorders. The part the ENS plays in neurological disorders, as a portal or participant, has also become increasingly evident. ENS structure and neurochemistry resemble that of the CNS, therefore pathogenic mechanisms that give rise to CNS disorders might also lead to ENS dysfunction, and nerves that interconnect the ENS and CNS can be conduits for disease spread. We review evidence for ENS dysfunction in the aetiopathogenesis of autism spectrum disorder, amyotrophic lateral sclerosis, transmissible spongiform encephalopathies, Parkinson disease and Alzheimer disease. Animal models suggest that common pathophysiological mechanisms account for the frequency of gastrointestinal comorbidity in these conditions. Moreover, the neurotropic pathogen, varicella zoster virus (VZV), unexpectedly establishes latency in enteric and other autonomic neurons that do not innervate skin. VZV reactivation in these neurons produces no rash and is therefore a clandestine cause of gastrointestinal disease, meningitis and strokes. The gut-brain alliance has raised consciousness as a contributor to health, but a gut-brain axis that contributes to disease merits equal attention.
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Affiliation(s)
- Meenakshi Rao
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, 622 West 168th Street, New York, New York 10032, USA
| | - Michael D. Gershon
- Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, 630 West 168th Street, New York, New York 10032, USA
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Costagliola A. Glial fibrillary acidic protein-immunoreactive enteroglial cells in the jejunum of cattle. Acta Histochem 2015; 117:576-81. [PMID: 26059029 DOI: 10.1016/j.acthis.2015.05.004] [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: 03/16/2015] [Revised: 05/16/2015] [Accepted: 05/19/2015] [Indexed: 02/07/2023]
Abstract
Enteroglial cells (EGCs) play critical roles in human health and disease, however, EGC-dependent neuropathies also affect commercially important animal species. Due to the lack of data on the distribution and phenotypic characterization of the EGCs throughout the bovine gastrointestinal tract, in this study the topographic localization of EGCs in the jejunum of healthy cattle was investigated by immunofluorescence using the glial specific marker glial fibrillary acidic protein (GFAP) and the panneuronal marker PGP 9.5. This analysis was conducted on both cryosections and whole mount preparations including the myenteric and the submucous plexuses of the bovine jejunum. The results obtained showed the presence of a large subpopulation of GFAP-expressing EGCs in the main plexuses and within the muscle layers, whereas only few GFAP-positive glial processes were found within the deeper layer of the mucosa, and they never reached the mucosal epithelium. Three different EGC subtypes, namely I, III and IV types were recognized in the examined tract of the bovine intestine. Overall, our results provide the basis for future investigations aimed at elucidating the functional role of the GFAP-containing EGCs which is crucial for a better understanding of the physio-pathology of the bovine intestine.
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Coelho-Aguiar JDM, Bon-Frauches AC, Gomes ALT, Veríssimo CP, Aguiar DP, Matias D, Thomasi BBDM, Gomes AS, Brito GADC, Moura-Neto V. The enteric glia: identity and functions. Glia 2015; 63:921-35. [PMID: 25703790 DOI: 10.1002/glia.22795] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 01/07/2015] [Indexed: 01/04/2023]
Abstract
Enteric glial cells were first described at the end of the 19th century, but they attracted more interest from researchers only in the last decades of the 20th. Although, they have a different embryological origin, the enteric GLIA share many characteristics with astrocytes, the main glial cell type of the central nervous system (CNS), such as in their expression of the same markers and in their functions. Here we review the construction of the enteric nervous system (ENS), with a focus on enteric glia, and also the main studies that have revealed the action of enteric glia in different aspects of gastrointestinal tract homeostasis, such as in the intestinal barrier, in communications with neurons, and in their action as progenitor cells. We also discuss recent discoveries about the roles of enteric glia in different disorders that affect the ENS, such as degenerative pathologies including Parkinson's and prion diseases, and in cases of intestinal diseases and injury.
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Affiliation(s)
- Juliana de Mattos Coelho-Aguiar
- Instituto Estadual do Cérebro Paulo Niemeyer, Secretaria de Estado de Saúde do Rio de Janeiro - SES/RJ, Rio de Janeiro, Brazil; Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Herdewyn S, Cirillo C, Van Den Bosch L, Robberecht W, Vanden Berghe P, Van Damme P. Prevention of intestinal obstruction reveals progressive neurodegeneration in mutant TDP-43 (A315T) mice. Mol Neurodegener 2014; 9:24. [PMID: 24938805 PMCID: PMC4088917 DOI: 10.1186/1750-1326-9-24] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 06/06/2014] [Indexed: 12/12/2022] Open
Abstract
Background Intraneuronal inclusions of TAR DNA-binding protein 43 (TDP-43) have been found in the majority of Amyotrophic Lateral Sclerosis (ALS) patients. Mutations in the gene encoding TDP-43 cause familial ALS. Transgenic mice expressing mutant TDP-43 with one such mutation (TDP-43 (A315T)) under control of the murine prion promoter develop motor symptoms, but their use is currently hampered by sudden death. We aimed to understand and overcome the cause of sudden death in TDP-43 (A315T) mice. Since intestinal obstruction was suspected to be the cause, intestinal motility of TDP-43 (A315T) mice was studied in an ex-vivo pellet propulsion assay. The effect on the enteric and motor phenotype was assessed, both in animals on normal chow or on a jellified fiber deprived diet, aimed at preventing intestinal obstruction. Results The frequency of the propulsive motor complexes was significantly reduced in the colon of TDP-43 (A315T) compared to non transgenic (NTG) mice. Immunohistochemistry revealed significant enlargement in size and reduction in number of the nitric oxide synthase (NOS) neurons in the myenteric plexus of TDP-43 (A315T) mice. Prevention of intestinal obstruction by jellified food abolished sudden death, allowing the motor phenotype to develop and slowly progress with a more pronounced degeneration of upper and lower motor axons. A downregulation of endogenous TDP-43 mRNA and protein levels was observed prior to neurodegeneration. Conclusion TDP-43 (A315T) mice suffer from intestinal dysmotility due to degeneration of NOS neurons in the myenteric plexus. Feeding the mice jellified food prevents sudden death and allows the motor phenotype to progress.
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Affiliation(s)
| | | | | | | | | | - Philip Van Damme
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Research Institute for Neuroscience and Disease (LIND), Leuven, Belgium.
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Sadeghinezhad J, Sorteni C, Di Guardo G, D'Agostino C, Agrimi U, Nonno R, Chiocchetti R. Neurochemistry of myenteric plexus neurons of bank vole (Myodes glareolus) ileum. Res Vet Sci 2013; 95:846-53. [PMID: 23969205 DOI: 10.1016/j.rvsc.2013.07.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 06/13/2013] [Accepted: 07/28/2013] [Indexed: 11/16/2022]
Abstract
The neurochemistry of enteric neurons differs among species of small laboratory rodents (guinea-pig, mouse, rat). In this study we characterized the phenotype of ileal myenteric plexus (MP) neuronal cells and fibers of the bank vole (Myodes glareolus), a common rodent living in Europe and in Northern Asia which is also employed in prion experimental transmission studies. Six neuronal markers were tested: choline acetyltransferase (ChAT), neuronal nitric oxide synthase (nNOS), calbindin (CALB), calcitonin gene-related peptide (CGRP) and substance P (SP), along with HuC/D as a pan-neuronal marker. Neurons expressing ChAT- and nNOS-immunoreactivity (IR) were 36 ± 12% and 24 ± 5%, respectively. Those expressing CGRP-, SP- and CALB-IR were 3 ± 3%, 21 ± 5% and 6 ± 2%, respectively. Therefore, bank vole MPs differ consistently from murine MPs in neurons expressing CGRP-, SP- and CALB-IR. These data may contribute to define the prion susceptibility of neuron cell populations residing within ileal MPs from bank voles, along with their morpho-functional alterations following oral experimental prion challenge.
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Affiliation(s)
- J Sadeghinezhad
- Department of Veterinary Medical Science, University of Bologna, Ozzano dell'Emilia, Bologna, Italy; Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
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Martin GR, Alvarez AL, Bashashati M, Keenan CM, Jirik FR, Sharkey KA. Endogenous cellular prion protein regulates contractility of the mouse ileum. Neurogastroenterol Motil 2012; 24:e412-24. [PMID: 22762267 DOI: 10.1111/j.1365-2982.2012.01970.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND Cellular prion protein (PrP(C) ) is expressed in the enteric nervous system (ENS), however, its physiological role has not been identified. Studies suggest that PrP(C) can function as a metal-binding protein, as absence of the protein has been linked to altered copper metabolism and atypical synaptic activity. Because copper is known to modulate smooth muscle relaxation, we tested the hypothesis that PrP(C) deficiency would alter intestinal contractility. METHODS We examined electrically evoked ileal contractility in Prnp(-/-) or wild type littermate mice and the effects of copper or copper chelation. PrP(C) expression was studied in whole mount ileal preparations of mice and guinea pigs by immunohistochemistry. KEY RESULTS Relative to wild type mice, ileal tissues of Prnp(-/-) mice exhibited reduced electrical field stimulation (EFS)-evoked contractility. Furthermore, EFS-induced relaxation, as a percentage of that induced by a nitric oxide donor, was enhanced. Addition of a copper donor to the organ bath increased, whereas the addition of a copper chelator inhibited, nitric oxide donor-induced ileal relaxation in Prnp(-/-) mice. PrP(C) was expressed on nerve fibers or terminals, and some cell bodies in the myenteric and submucosal plexuses of wild type mice. PrP(C) colocalized with a neuron-specific ectonucleotidase, nucleoside triphosphate diphosphohydrolase 3 (NTPDase3), but to only a limited extent with GFAP, a marker of enteric glia. Guinea pigs expressed PrP(C) in nerve fibers or terminals and enteric glia in the myenteric and submucosal plexuses. CONCLUSIONS & INFERENCES Our findings suggest that PrP(C) , which is abundant in the ENS, has a role in the regulation of ileal contractility.
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Affiliation(s)
- G R Martin
- Hotchkiss Brain Institute and Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.
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Furness JB, Poole DP. NONRUMINANT NUTRITION SYMPOSIUM: Involvement of gut neural and endocrine systems in pathological disorders of the digestive tract1,2. J Anim Sci 2012; 90:1203-12. [DOI: 10.2527/jas.2011-4825] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Bassotti G, Villanacci V, Bellomi A, Fante R, Cadei M, Vicenzi L, Tonelli F, Nesi G, Asteria CR. An assessment of enteric nervous system and estroprogestinic receptors in obstructed defecation associated with rectal intussusception. Neurogastroenterol Motil 2012; 24:e155-61. [PMID: 22188470 DOI: 10.1111/j.1365-2982.2011.01850.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND The pathophysiological basis of obstructed defecation (OD) is still incompletely understood. In particular, few or no data are available concerning the enteric nervous system (ENS) in this condition. We investigated ENS abnormalities in patients with OD, undergoing surgery, together with the presence of estrogen (α and β) and progesterone receptors, and compare the results with those obtained in controls. METHODS Full-thickness rectal samples were obtained from 17 patients undergoing stapled transanal rectal resection for OD associated with rectal intussusception. Samples were analyzed by immunohistochemistry for enteric neurons, enteric glial cells, interstitial cells of Cajal (ICC), and for estrogen and progesterone receptors. Data were compared with those obtained in 10 controls. KEY RESULTS No differences between patients and controls were found for enteric neurons, whereas (compared with controls) OD patients displayed a significant decrease of enteric glial cells in both the submucous (P = 0.0006) and the myenteric (P < 0.0001) plexus. ICC were significantly increased in patients in the submucosal surface (P < 0.0001) and the myenteric area (P < 0.0001). Concerning estroprogestinic receptors, both were present on ICC in patients and controls. Estrogen receptors α and progesterone receptors were absent on enteric neurons and enteric glial cells in patients and controls, whereas estrogen receptors β were present in all controls and in 69% of patients' enteric neurons (P = 0.18) and in 12% of patients' glial cells (P = 0.0001). CONCLUSIONS & INFERENCES Patients with OD associated to rectal intussusception display abnormalities of the ENS and of estrogen receptors β.
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Affiliation(s)
- Gabrio Bassotti
- Gastroenterology and Hepatology Section, Department of Clinical and Experimental Medicine, University of Perugia, Perugia, Italy.
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Natale G, Pasquali L, Paparelli A, Fornai F. Parallel manifestations of neuropathologies in the enteric and central nervous systems. Neurogastroenterol Motil 2011; 23:1056-65. [PMID: 21951862 DOI: 10.1111/j.1365-2982.2011.01794.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Neurodegenerative diseases may extend outside the central nervous system (CNS) and involve the gastrointestinal (GI) tract. The gut would appear to be a pathological marker for neurodegeneration, as well as a site for studying the pathophysiology of neurodegeneration. In fact, both in the ENS and CNS, misfolded proteins are likely to initiate a process of neurodegeneration. For example, the very same protein aggregates can be detected both in the ENS and CNS. In both systems, misfolded proteins are likely to share common cell-to-cell diffusion mechanisms, which may occur through a parallel prion-like diffusion process. Independently from the enteric or central origin, misfolded proteins may proceed along the following steps, they: (i) form aggregates; (ii) are expressed on plasma membrane; (iii) are secreted extracellularly; (iv) are glycated to form advanced glycation end-products (AGEs); (v) are internalized through specific receptors placed on neighboring cells (RAGEs); (vi) are cleared by autophagy; and (vii) are neurotoxic. These features are common for a-synuclein (in Parkinson's disease and other synucleinopathies), β-amyloid and tau (in degenerative dementia), SOD-1 and TDP43 (in amyotrophic lateral sclerosis), and PrPsc (in prion diseases). While in some diseases these features are common to both ENS and CNS, in others this remains a working hypothesis. PURPOSE This review analyzes GI alterations from a pathological perspective to assess whether the enteric nervous system (ENS) mirrors the neuropathology described in the CNS. We discuss the potential mechanisms that lead to the onset and spread of neurodegeneration within the gut, from the gut to the brain, and vice versa.
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Affiliation(s)
- G Natale
- Department of Human Morphology and Applied Biology, University of Pisa, Italy
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Natale G, Ferrucci M, Lazzeri G, Paparelli A, Fornai F. Transmission of prions within the gut and towards the central nervous system. Prion 2011; 5:142-9. [PMID: 21814041 DOI: 10.4161/pri.5.3.16328] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The prion protein is a glycoprotein characterized by a folded α-helical structure that, under pathological conditions, misfolds and aggregates into its infectious isoform as β-sheet rich amyloidic deposits. The accumulation of the abnormal protein is responsible for a group of progressive and fatal disorders characterized by vacuolation, gliosis, and spongiform degeneration. Prion disorders are characterized by a triple aetiology: familial, sporadic or acquired, although most cases are sporadic. The mechanisms underlying prion neurotoxicity remain controversial, while novel findings lead to hypothesize intriguing pathways responsible for prion spreading. The present review aims to examine the involvement of the gastrointestinal tract and hypothesizes the potential mechanisms underlying cell-to-cell transmission of the prion protein. In particular, a special emphasis is posed on the mechanisms of prion transmission within the gut and towards the central nervous system. The glycation of prion protein to form advanced glycation end-products (AGE) interacting with specific receptors placed on neighboring cells (RAGE) represents the key hypothesis to be discussed.
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Affiliation(s)
- Gianfranco Natale
- Department of Human Morphology and Applied Biology, University of Pisa, Pisa, Italy
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Bassotti G, Villanacci V. Can "functional" constipation be considered as a form of enteric neuro-gliopathy? Glia 2010; 59:345-50. [PMID: 21264943 DOI: 10.1002/glia.21115] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 11/03/2010] [Indexed: 12/12/2022]
Abstract
Constipation has been traditionally viewed and classified as a functional or idiopathic disorder. However, evidence has been accumulating that suggests how constipation might be considered as due to abnormalities of the enteric nervous system, since alterations of this system, not evident in conventional histological examination, may be present in these patients. These abnormalities often consist in decrease or loss of the enteric glial cells, a pathological finding present in most types of constipation so far investigated. In this article we will discuss these evidences, and will try to consider constipation no more as a simple functional or idiopathic disorder but as a form of enteric neuro-gliopathy.
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Affiliation(s)
- Gabrio Bassotti
- Department of Clinical and Experimental Medicine, Gastroenterology and Hepatology Section, University of Perugia, Italy.
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Characterization of sheep (Ovis aries) palatine tonsil innervation. Neuroscience 2009; 161:813-26. [DOI: 10.1016/j.neuroscience.2009.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 04/02/2009] [Accepted: 04/07/2009] [Indexed: 11/20/2022]
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Sharkey KA. Tyrosine hydroxylase in the stalk-median eminence and posterior pituitary is inactivated only during the plateau phase of the preovulatory prolactin surge. Endocrinology 1989; 125:918-25. [PMID: 25689252 DOI: 10.1172/jci76303] [Citation(s) in RCA: 135] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This study examined changes in the activity of tyrosine hydroxylase (TH) in the stalk-median eminence (SME) and posterior pituitary (PP) during the preovulatory PRL surge. Immature female rats were injected with PMSG on day 28. Blood PRL levels were low on the morning of day 30, rose to a peak from 1400-1600 h, remained at a lower plateau from 1800-2400 h, and declined to basal levels on the morning of day 31. SME, PP, and striatum were removed from PMSG-treated rats at selected times during the periovulatory period and from age-matched control rats. TH activity was determined in tissue homogenates by a coupled hydroxylation-decarboxylation assay. Apparent Km and maximum velocity values with respect to 6-methyl tetrahydropterine were estimated from substrate saturation curves. The kinetic parameters for TH in either the SME or the PP of control rats were similar at 1100 and 1800 h on day 30. However, the apparent Km in both tissues was significantly lower than that in the striatum. The affinity of TH in the SME and PP was unchanged before and during the peak phase of the PRL surge, reduced significantly during the late plateau, and returned to presurge levels in the morning of day 31. TH activity in the striatum was similar at all times examined. To determine the state of activation of the enzyme, tissue homogenates were preincubated with cAMP, ATP, and magnesium. TH activity in the SME during the peak phase was unchanged by cAMP, and that in the PP was modestly increased. The relatively inactive enzyme in both tissues during the plateau phase was markedly activated by a cAMP-dependent mechanism. The low affinity of striatal TH was greatly increased by cAMP at both times. These data suggest that TH in the SME and PP exists in an activated state most of the time and is transiently inactivated during the plateau phase of the PRL surge. In contrast, TH in the striatum is relatively inactive in the basal state and is not affected by hormonal changes induced by PMSG. We conclude that the peak PRL surge occurs in spite of active dopamine (DA) neurons, suggesting that it is generated by a nondopaminergic mechanism. Decreased TH activity in DA neurons in the SME and PP may prolong the PRL surge during the plateau phase, whereas increased DA activity coincides with the termination of the surge.
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