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Zhou L, Lian H, Yin Y, Zheng YS, Han YX, Liu GQ, Wang ZY. New insights into muscularis macrophages in the gut: from their origin to therapeutic targeting. Immunol Res 2023; 71:785-799. [PMID: 37219708 DOI: 10.1007/s12026-023-09397-x] [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: 02/10/2023] [Accepted: 05/15/2023] [Indexed: 05/24/2023]
Abstract
Muscularis macrophages, as the most abundant immune cells in the intestinal muscularis externa, exhibit tissue protective phenotype in the steady state. Owing to tremendous advances in technology, we now know the fact that muscularis macrophages are a heterogeneous population of cells which could be divided into different functional subsets depending on their anatomic niches. There is emerging evidence showing that these subsets, through molecular interactions with their neighbours, take part in a wide range of physiological and pathophysiological processes in the gut. In this review, we summarize recent progress (particularly over the past 4 years) on distribution, morphology, origin and functions of muscularis macrophages and, where possible, the characteristics of specific subsets in response to the microenvironment they occupy, with particular emphasis on their role in muscular inflammation. Furthermore, we also integrate their role in inflammation-related gastrointestinal disorders, such as post-operative ileus and diabetic gastroparesis, in order to propose future therapeutic strategies.
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Affiliation(s)
- Li Zhou
- Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
- Xinxiang Key Laboratory of Molecular Neurology, Xinxiang Medical University, Xinxiang, 453003, China
| | - Hui Lian
- Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
- Xinxiang Key Laboratory of Molecular Neurology, Xinxiang Medical University, Xinxiang, 453003, China
| | - Yue Yin
- Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Yuan-Sheng Zheng
- Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Yu-Xin Han
- Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Gao-Qi Liu
- Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Zhi-Yong Wang
- Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China.
- Xinxiang Key Laboratory of Molecular Neurology, Xinxiang Medical University, Xinxiang, 453003, China.
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2
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Schmitt V, Masanetz RK, Weidenfeller M, Ebbinghaus LS, Süß P, Rosshart SP, von Hörsten S, Zunke F, Winkler J, Xiang W. Gut-to-brain spreading of pathology in synucleinopathies: A focus on molecular signalling mediators. Behav Brain Res 2023; 452:114574. [PMID: 37423320 DOI: 10.1016/j.bbr.2023.114574] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 07/03/2023] [Accepted: 07/06/2023] [Indexed: 07/11/2023]
Abstract
Synucleinopathies are a group of neurodegenerative disorders, classically characterized by the accumulation of aggregated alpha synuclein (aSyn) in the central nervous system. Parkinson's disease (PD) and multiple system atrophy (MSA) are the two prominent members of this family. Current treatment options mainly focus on the motor symptoms of these diseases. However, non-motor symptoms, including gastrointestinal (GI) symptoms, have recently gained particular attention, as they are frequently associated with synucleinopathies and often arise before motor symptoms. The gut-origin hypothesis has been proposed based on evidence of an ascending spreading pattern of aggregated aSyn from the gut to the brain, as well as the comorbidity of inflammatory bowel disease and synucleinopathies. Recent advances have shed light on the mechanisms underlying the progression of synucleinopathies along the gut-brain axis. Given the rapidly expanding pace of research in the field, this review presents a summary of the latest findings on the gut-to-brain spreading of pathology and potential pathology-reinforcing mediators in synucleinopathies. Here, we focus on 1) gut-to-brain communication pathways, including neuronal pathways and blood circulation, and 2) potential molecular signalling mediators, including bacterial amyloid proteins, microbiota dysbiosis-induced alterations in gut metabolites, as well as host-derived effectors, including gut-derived peptides and hormones. We highlight the clinical relevance and implications of these molecular mediators and their possible mechanisms in synucleinopathies. Moreover, we discuss their potential as diagnostic markers in distinguishing the subtypes of synucleinopathies and other neurodegenerative diseases, as well as for developing novel individualized therapeutic options for synucleinopathies.
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Affiliation(s)
- Verena Schmitt
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
| | - Rebecca Katharina Masanetz
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
| | - Martin Weidenfeller
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
| | - Lara Savannah Ebbinghaus
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
| | - Patrick Süß
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
| | - Stephan P Rosshart
- Department of Microbiome Research, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
| | - Stephan von Hörsten
- Department for Experimental Therapy, University Hospital Erlangen, Preclinical Experimental Center, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
| | - Friederike Zunke
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
| | - Jürgen Winkler
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
| | - Wei Xiang
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany.
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Chaudhry TS, Senapati SG, Gadam S, Mannam HPSS, Voruganti HV, Abbasi Z, Abhinav T, Challa AB, Pallipamu N, Bheemisetty N, Arunachalam SP. The Impact of Microbiota on the Gut-Brain Axis: Examining the Complex Interplay and Implications. J Clin Med 2023; 12:5231. [PMID: 37629273 PMCID: PMC10455396 DOI: 10.3390/jcm12165231] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/30/2023] [Accepted: 08/02/2023] [Indexed: 08/27/2023] Open
Abstract
The association and interaction between the central nervous system (CNS) and enteric nervous system (ENS) is well established. Essentially ENS is the second brain, as we call it. We tried to understand the structure and function, to throw light on the functional aspect of neurons, and address various disease manifestations. We summarized how various neurological disorders influence the gut via the enteric nervous system and/or bring anatomical or physiological changes in the enteric nervous system or the gut and vice versa. It is known that stress has an effect on Gastrointestinal (GI) motility and causes mucosal erosions. In our literature review, we found that stress can also affect sensory perception in the central nervous system. Interestingly, we found that mutations in the neurohormone, serotonin (5-HT), would result in dysfunctional organ development and further affect mood and behavior. We focused on the developmental aspects of neurons and cognition and their relation to nutritional absorption via the gastrointestinal tract, the development of neurodegenerative disorders in relation to the alteration in gut microbiota, and contrariwise associations between CNS disorders and ENS. This paper further summarizes the synergetic relation between gastrointestinal and neuropsychological manifestations and emphasizes the need to include behavioral therapies in management plans.
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Affiliation(s)
| | | | - Srikanth Gadam
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA; (S.G.); (N.P.)
| | - Hari Priya Sri Sai Mannam
- GIH Artificial Intelligence Laboratory (GAIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA; (H.P.S.S.M.); (H.V.V.); (Z.A.); (T.A.); (N.B.)
| | - Hima Varsha Voruganti
- GIH Artificial Intelligence Laboratory (GAIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA; (H.P.S.S.M.); (H.V.V.); (Z.A.); (T.A.); (N.B.)
| | - Zainab Abbasi
- GIH Artificial Intelligence Laboratory (GAIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA; (H.P.S.S.M.); (H.V.V.); (Z.A.); (T.A.); (N.B.)
| | - Tushar Abhinav
- GIH Artificial Intelligence Laboratory (GAIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA; (H.P.S.S.M.); (H.V.V.); (Z.A.); (T.A.); (N.B.)
| | | | - Namratha Pallipamu
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA; (S.G.); (N.P.)
| | - Niharika Bheemisetty
- GIH Artificial Intelligence Laboratory (GAIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA; (H.P.S.S.M.); (H.V.V.); (Z.A.); (T.A.); (N.B.)
| | - Shivaram P. Arunachalam
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA; (S.G.); (N.P.)
- GIH Artificial Intelligence Laboratory (GAIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA; (H.P.S.S.M.); (H.V.V.); (Z.A.); (T.A.); (N.B.)
- Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
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Rocha E, Chamoli M, Chinta SJ, Andersen JK, Wallis R, Bezard E, Goldberg M, Greenamyre T, Hirst W, Kuan WL, Kirik D, Niedernhofer L, Rappley I, Padmanabhan S, Trudeau LE, Spillantini M, Scott S, Studer L, Bellantuono I, Mortiboys H. Aging, Parkinson's Disease, and Models: What Are the Challenges? AGING BIOLOGY 2023; 1:e20230010. [PMID: 38978807 PMCID: PMC11230631 DOI: 10.59368/agingbio.20230010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Parkinson's disease (PD) is a chronic, neurodegenerative condition characterized by motor symptoms such as bradykinesia, rigidity, and tremor, alongside multiple nonmotor symptoms. The appearance of motor symptoms is linked to progressive dopaminergic neuron loss within the substantia nigra. PD incidence increases sharply with age, suggesting a strong association between mechanisms driving biological aging and the development and progression of PD. However, the role of aging in the pathogenesis of PD remains understudied. Numerous models of PD, including cell models, toxin-induced models, and genetic models in rodents and nonhuman primates (NHPs), reproduce different aspects of PD, but preclinical studies of PD rarely incorporate age as a factor. Studies using patient neurons derived from stem cells via reprogramming methods retain some aging features, but their characterization, particularly of aging markers and reproducibility of neuron type, is suboptimal. Investigation of age-related changes in PD using animal models indicates an association, but this is likely in conjunction with other disease drivers. The biggest barrier to drawing firm conclusions is that each model lacks full characterization and appropriate time-course assessments. There is a need to systematically investigate whether aging increases the susceptibility of mouse, rat, and NHP models to develop PD and understand the role of cell models. We propose that a significant investment in time and resources, together with the coordination and sharing of resources, knowledge, and data, is required to accelerate progress in understanding the role of biological aging in PD development and improve the reliability of models to test interventions.
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Affiliation(s)
- Emily Rocha
- Pittsburgh Institute for Neurodegenerative Diseases and Department of Neurology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Shankar J Chinta
- Buck Institute for Research on Aging, Novato, CA, USA
- Touro University California, College of Pharmacy, Vallejo, CA, USA
| | | | - Ruby Wallis
- The Healthy Lifespan Institute, Sheffield, United Kingdom
| | | | | | - Tim Greenamyre
- Pittsburgh Institute for Neurodegenerative Diseases and Department of Neurology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - We-Li Kuan
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Deniz Kirik
- Brain Repair and Imaging in Neural Systems (BRAINS), Lund, Sweden
| | - Laura Niedernhofer
- Institute on the Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN, USA
| | - Irit Rappley
- Recursion pharmaceuticals, Salt Lake City, UT, USA
| | | | - Louis-Eric Trudeau
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Maria Spillantini
- Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | | | - Lorenz Studer
- The Center for Stem Cell Biology and Developmental Biology Program, Sloan-Kettering Institute for Cancer Research, New York, NY, USA
| | - Ilaria Bellantuono
- The Healthy Lifespan Institute, Sheffield, United Kingdom
- Department of Oncology and Metabolism, The Medical School, Sheffield, United Kingdom
| | - Heather Mortiboys
- The Healthy Lifespan Institute, Sheffield, United Kingdom
- Department of Neuroscience, Sheffield Institute of Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kindgom
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Montanari M, Imbriani P, Bonsi P, Martella G, Peppe A. Beyond the Microbiota: Understanding the Role of the Enteric Nervous System in Parkinson's Disease from Mice to Human. Biomedicines 2023; 11:1560. [PMID: 37371655 DOI: 10.3390/biomedicines11061560] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 06/29/2023] Open
Abstract
The enteric nervous system (ENS) is a nerve network composed of neurons and glial cells that regulates the motor and secretory functions of the gastrointestinal (GI) tract. There is abundant evidence of mutual communication between the brain and the GI tract. Dysfunction of these connections appears to be involved in the pathophysiology of Parkinson's disease (PD). Alterations in the ENS have been shown to occur very early in PD, even before central nervous system (CNS) involvement. Post-mortem studies of PD patients have shown aggregation of α-synuclein (αS) in specific subtypes of neurons in the ENS. Subsequently, αS spreads retrogradely in the CNS through preganglionic vagal fibers to this nerve's dorsal motor nucleus (DMV) and other central nervous structures. Here, we highlight the role of the ENS in PD pathogenesis based on evidence observed in animal models and using a translational perspective. While acknowledging the putative role of the microbiome in the gut-brain axis (GBA), this review provides a comprehensive view of the ENS not only as a "second brain", but also as a window into the "first brain", a potentially crucial element in the search for new therapeutic approaches that can delay and even cure the disease.
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Affiliation(s)
- Martina Montanari
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
- Department of Systems Neuroscience, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Paola Imbriani
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
- Clinical Neuroscience, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
| | - Paola Bonsi
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Giuseppina Martella
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Antonella Peppe
- Clinical Neuroscience, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
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Raj K, Singh S, Chib S, Mallan S. Microbiota- Brain-Gut-Axis Relevance to Parkinson's Disease: Potential Therapeutic Effects of Probiotics. Curr Pharm Des 2022; 28:3049-3067. [PMID: 36200207 DOI: 10.2174/1381612828666221003112300] [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: 04/20/2022] [Accepted: 09/02/2022] [Indexed: 01/28/2023]
Abstract
Parkinson's disease (PD) is the second most common type of neurogenerative disease among middleaged and older people, characterized by aggregation of alpha-synuclein and dopaminergic neuron loss. The microbiota- gut-brain axis is a dynamic bidirectional communication network and is involved in the pathogenesis of PD. The aggregation of misfolded protein alpha-synuclein is a neuropathological characteristic of PD, originates in the gut and migrates to the central nervous system (CNS) through the vagus nerve and olfactory bulb. The change in the architecture of gut microbiota increases the level short-chain fatty acids (SCFAs) and other metabolites, acting on the neuroendocrine system and modulating the concentrations of gamma-Aminobutyric acid (GABA), serotonin, and other neurotransmitters. It also alters the vagus and intestinal signalling, influencing the brain and behaviour by activating microglia and systemic cytokines. Both experimental and clinical reports indicate the role of intestinal dysbiosis and microbiota host interaction in neurodegeneration. Probiotics are live microorganisms that modify the gut microbiota in the small intestine to avoid neurological diseases. Probiotics have been shown in clinical and preclinical studies to be effective in the treatment of PD by balancing the gut microbiota. In this article, we described the role of gut-microbiota in the pathogenesis of PD. The article aims to explore the mechanistic strategy of the gut-brain axis and its relation with motor impairment and the use of probiotics to maintain gut microbial flora and prevent PD-like symptoms.
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Affiliation(s)
- Khadga Raj
- Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab 142001, India
| | - Shamsher Singh
- Neuroscience Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab 142001, India
| | - Shivani Chib
- Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab 142001, India
| | - Sudhanshu Mallan
- Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab 142001, India
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Bishop ES, Namkoong H, Aurelian L, McCarthy M, Nallagatla P, Zhou W, Neshatian L, Gurland B, Habtezion A, Becker L. Age-dependent Microglial Disease Phenotype Results in Functional Decline in Gut Macrophages. GASTRO HEP ADVANCES 2022; 2:261-276. [PMID: 36908772 PMCID: PMC10003669 DOI: 10.1016/j.gastha.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 09/15/2022] [Indexed: 10/14/2022]
Abstract
BACKGROUND AND AIMS Muscularis macrophages (MMs) are tissue-resident macrophages in the gut muscularis externa which play a supportive role to the enteric nervous system. We have previously shown that age-dependent MM alterations drive low-grade enteric nervous system inflammation, resulting in neuronal loss and disruption of gut motility. The current studies were designed to identify the MM genetic signature involved in these changes, with particular emphasis on comparison to genes in microglia, the central nervous system macrophage population involved in age-dependent cognitive decline. METHODS Young (3 months) and old (16-24 months) C57BL/6 mice and human tissue were studied. Immune cells from mouse small intestine, colon, and spinal cord and human colon were dissociated, immunophenotyped by flow cytometry, and examined for gene expression by single-cell RNA sequencing and quantitative real-time PCR. Phagocytosis was assessed by in vivo injections of pHrodo beads (Invitrogen). Macrophage counts were performed by immunostaining of muscularis whole mounts. RESULTS MMs from young and old mice express homeostatic microglial genes, including Gpr34, C1qc, Trem2, and P2ry12. An MM subpopulation that becomes more abundant with age assumes a geriatric state (GS) phenotype characterized by increased expression of disease-associated microglia genes including Cd9, Clec7a, Itgax (CD11c), Bhlhe40, Lgals3, IL-1β, and Trem2 and diminished phagocytic activity. Acquisition of the GS phenotype is associated with clearance of α-synuclein aggregates. Human MMs demonstrate a similar age-dependent acquisition of the GS phenotype associated with intracellular α-synuclein accumulation. CONCLUSION MMs demonstrate age-dependent genetic changes that mirror the microglial disease-associated microglia phenotype and result in functional decline.
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Affiliation(s)
- Estelle Spear Bishop
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University, Stanford, California
| | - Hong Namkoong
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University, Stanford, California
| | - Laure Aurelian
- Stanford University School of Medicine OFDD, Stanford, California
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Madison McCarthy
- Department of Surgery, Stanford University, Stanford, California
| | - Pratima Nallagatla
- Stanford Center for Genomics and Personalized Medicine, Stanford University, Stanford, California
| | - Wenyu Zhou
- Stanford Center for Genomics and Personalized Medicine, Stanford University, Stanford, California
- Department of Genetics, Stanford University, Stanford, California
| | - Leila Neshatian
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University, Stanford, California
| | - Brooke Gurland
- Department of Surgery, Stanford University, Stanford, California
| | - Aida Habtezion
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University, Stanford, California
| | - Laren Becker
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University, Stanford, California
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Klæstrup IH, Just MK, Holm KL, Alstrup AKO, Romero-Ramos M, Borghammer P, Van Den Berge N. Impact of aging on animal models of Parkinson's disease. Front Aging Neurosci 2022; 14:909273. [PMID: 35966779 PMCID: PMC9366194 DOI: 10.3389/fnagi.2022.909273] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 06/28/2022] [Indexed: 11/23/2022] Open
Abstract
Aging is the biggest risk factor for developing Parkinson's disease (PD), the second most common neurodegenerative disorder. Several animal models have been developed to explore the pathophysiology underlying neurodegeneration and the initiation and spread of alpha-synuclein-related PD pathology, and to investigate biomarkers and therapeutic strategies. However, bench-to-bedside translation of preclinical findings remains suboptimal and successful disease-modifying treatments remain to be discovered. Despite aging being the main risk factor for developing idiopathic PD, most studies employ young animals in their experimental set-up, hereby ignoring age-related cellular and molecular mechanisms at play. Consequently, studies in young animals may not be an accurate reflection of human PD, limiting translational outcomes. Recently, it has been shown that aged animals in PD research demonstrate a higher susceptibility to developing pathology and neurodegeneration, and present with a more disseminated and accelerated disease course, compared to young animals. Here we review recent advances in the investigation of the role of aging in preclinical PD research, including challenges related to aged animal models that are limiting widespread use. Overall, current findings indicate that the use of aged animals may be required to account for age-related interactions in PD pathophysiology. Thus, although the use of older animals has disadvantages, a model that better represents clinical disease within the elderly would be more beneficial in the long run, as it will increase translational value and minimize the risk of therapies failing during clinical studies. Furthermore, we provide recommendations to manage the challenges related to aged animal models.
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Affiliation(s)
- Ida Hyllen Klæstrup
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- DANDRITE-Danish Research Institute of Translational Neuroscience, Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
| | - Mie Kristine Just
- Institute for Clinical Medicine, Aarhus University, Aarhus, Denmark
- Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | | | - Aage Kristian Olsen Alstrup
- Institute for Clinical Medicine, Aarhus University, Aarhus, Denmark
- Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Marina Romero-Ramos
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- DANDRITE-Danish Research Institute of Translational Neuroscience, Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
| | - Per Borghammer
- Institute for Clinical Medicine, Aarhus University, Aarhus, Denmark
- Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Nathalie Van Den Berge
- Institute for Clinical Medicine, Aarhus University, Aarhus, Denmark
- Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
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9
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Hu Q, Hong M, Huang M, Gong Q, Zhang X, Uversky VN, Pan-Montojo F, Huang T, Zhou H, Zhu S. Age-dependent aggregation of α-synuclein in the nervous system of gut-brain axis is associated with caspase-1 activation. Metab Brain Dis 2022; 37:1669-1681. [PMID: 35089485 DOI: 10.1007/s11011-022-00917-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/17/2022] [Indexed: 12/15/2022]
Abstract
α-Synuclein (α-Syn) plays a key role in the development of Parkinson' desease (PD). As aging is acknowledged to be the greatest risk factor for PD, here we investigated α-Syn expression in the ileum, thoracic spinal cord, and midbrain of young (1-month-old), middle-aged (6-, 12-month-old) to old (18-month-old) mice. We demonstrated that both the levels of α-Syn monomers, oligomers and ratios of oligomers to monomers were increased with aging in the ileum, thoracic spinal cord, and midbrain. Whereas, the expression of tyrosine hydroxylase (TH), the rate-limiting enzyme for dopamine synthesis, was decreased with aging in the midbrain. We failed to find corresponding α-Syn mRNA increase with aging. However, we found an increased expression of caspase-1 in the ileum, thoracic spinal cord, and midbrain. A specific caspase-1 inhibitor VX765 significantly reduced levels of both the α-Syn monomers and oligomers triggered by the rotenone in vitro. Taken together, the increase in α-Syn aggregation with aging might not occur first in the gut, but simultaneously in the nervous system of gut-brain axis. The mechanism of the age-dependent aggregation of α-Syn in nervous system is likely triggered by the aging-related caspase-1 activation.
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Affiliation(s)
- Qi Hu
- Department of General Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Mei Hong
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, Hubei Province, 434023, People's Republic of China
- Clinical Molecular Immunology Center, School of Medicine, Yangtze University, Jingzhou, Hubei Province, 434023, People's Republic of China
- Department of Respiratory Medicine, Changhang General Hospital, Wuhan, 430015, People's Republic of China
| | - Mengyang Huang
- Department of Cardiac Function, Wuhan Central Hospital, Wuhan, 430345, People's Republic of China
| | - Quan Gong
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, Hubei Province, 434023, People's Republic of China.
- Clinical Molecular Immunology Center, School of Medicine, Yangtze University, Jingzhou, Hubei Province, 434023, People's Republic of China.
| | - Xiaofan Zhang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
- Laboratory of New Methods in Biology, Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow region, 142290, Russia
| | - Francisco Pan-Montojo
- Department of Psychiatry, Klinikum Der Ludwig-Maximilian Universität, 80336, Munich, Germany
| | - Teng Huang
- Department of General Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Honglian Zhou
- Department of General Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Suiqiang Zhu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
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10
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Chalazonitis A, Rao M, Sulzer D. Similarities and differences between nigral and enteric dopaminergic neurons unravel distinctive involvement in Parkinson's disease. NPJ Parkinsons Dis 2022; 8:50. [PMID: 35459867 PMCID: PMC9033791 DOI: 10.1038/s41531-022-00308-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 03/14/2022] [Indexed: 11/09/2022] Open
Abstract
In addition to the well-known degeneration of midbrain dopaminergic neurons, enteric neurons can also be affected in neurodegenerative disorders such as Parkinson's disease (PD). Dopaminergic neurons have recently been identified in the enteric nervous system (ENS). While ENS dopaminergic neurons have been shown to degenerate in genetic mouse models of PD, analyses of their survival in enteric biopsies of PD patients have provided inconsistent results to date. In this context, this review seeks to highlight the distinctive and shared factors and properties that control the evolution of these two sets of dopaminergic neurons from neuronal precursors to aging neurons. Although their cellular sources and developmental times of origin differ, midbrain and ENS dopaminergic neurons express many transcription factors in common and their respective environments express similar neurotrophic molecules. For example, Foxa2 and Sox6 are expressed by both populations to promote the specification, differentiation, and long-term maintenance of the dopaminergic phenotype. Both populations exhibit sustained patterns of excitability that drive intrinsic vulnerability over time. In disorders such as PD, colon biopsies have revealed aggregation of alpha-synuclein in the submucosal plexus where dopaminergic neurons reside and lack blood barrier protection. Thus, these enteric neurons may be more susceptible to neurotoxic insults and aggregation of α-synuclein that spreads from gut to midbrain. Under sustained stress, inefficient autophagy leads to neurodegeneration, GI motility dysfunction, and PD symptoms. Recent findings suggest that novel neurotrophic factors such as CDNF have the potential to be used as neuroprotective agents to prevent and treat ENS symptoms of PD.
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Affiliation(s)
- Alcmène Chalazonitis
- Department of Pathology & Cell Biology, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY, USA.
| | - Meenakshi Rao
- Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - David Sulzer
- Departments of Psychiatry, Neurology, and Pharmacology, Division of Molecular Therapeutics, New York State Psychiatry Institute, Columbia University, New York, NY, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815, USA
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11
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Geng ZH, Zhu Y, Li QL, Zhao C, Zhou PH. Enteric Nervous System: The Bridge Between the Gut Microbiota and Neurological Disorders. Front Aging Neurosci 2022; 14:810483. [PMID: 35517052 PMCID: PMC9063565 DOI: 10.3389/fnagi.2022.810483] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 01/17/2022] [Indexed: 12/12/2022] Open
Abstract
The gastrointestinal (GI) tract plays an essential role in food digestion, absorption, and the mucosal immune system; it is also inhabited by a huge range of microbes. The GI tract is densely innervated by a network of 200–600 million neurons that comprise the enteric nervous system (ENS). This system cooperates with intestinal microbes, the intestinal immune system, and endocrine systems; it forms a complex network that is required to maintain a stable intestinal microenvironment. Understanding how gut microbes influence the ENS and central nervous system (CNS) has been a significant research subject over the past decade. Moreover, accumulating evidence from animal and clinical studies has revealed that gut microbiota play important roles in various neurological diseases. However, the causal relationship between microbial changes and neurological disorders currently remains unproven. This review aims to summarize the possible contributions of GI microbiota to the ENS and CNS. It also provides new insights into furthering our current understanding of neurological disorders.
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Affiliation(s)
- Zi-Han Geng
- Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yan Zhu
- Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Quan-Lin Li
- Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
- Shanghai Collaborative Innovation Center of Endoscopy, Shanghai, China
- *Correspondence: Quan-Lin Li,
| | - Chao Zhao
- Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences & National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
- Chao Zhao,
| | - Ping-Hong Zhou
- Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
- Shanghai Collaborative Innovation Center of Endoscopy, Shanghai, China
- Ping-Hong Zhou,
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12
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Van Den Berge N, Ulusoy A. Animal models of brain-first and body-first Parkinson's disease. Neurobiol Dis 2022; 163:105599. [DOI: 10.1016/j.nbd.2021.105599] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 12/14/2021] [Accepted: 12/20/2021] [Indexed: 12/15/2022] Open
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13
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Sorboni SG, Moghaddam HS, Jafarzadeh-Esfehani R, Soleimanpour S. A Comprehensive Review on the Role of the Gut Microbiome in Human Neurological Disorders. Clin Microbiol Rev 2022; 35:e0033820. [PMID: 34985325 PMCID: PMC8729913 DOI: 10.1128/cmr.00338-20] [Citation(s) in RCA: 162] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The human body is full of an extensive number of commensal microbes, consisting of bacteria, viruses, and fungi, collectively termed the human microbiome. The initial acquisition of microbiota occurs from both the external and maternal environments, and the vast majority of them colonize the gastrointestinal tract (GIT). These microbial communities play a central role in the maturation and development of the immune system, the central nervous system, and the GIT system and are also responsible for essential metabolic pathways. Various factors, including host genetic predisposition, environmental factors, lifestyle, diet, antibiotic or nonantibiotic drug use, etc., affect the composition of the gut microbiota. Recent publications have highlighted that an imbalance in the gut microflora, known as dysbiosis, is associated with the onset and progression of neurological disorders. Moreover, characterization of the microbiome-host cross talk pathways provides insight into novel therapeutic strategies. Novel preclinical and clinical research on interventions related to the gut microbiome for treating neurological conditions, including autism spectrum disorders, Parkinson's disease, schizophrenia, multiple sclerosis, Alzheimer's disease, epilepsy, and stroke, hold significant promise. This review aims to present a comprehensive overview of the potential involvement of the human gut microbiome in the pathogenesis of neurological disorders, with a particular emphasis on the potential of microbe-based therapies and/or diagnostic microbial biomarkers. This review also discusses the potential health benefits of the administration of probiotics, prebiotics, postbiotics, and synbiotics and fecal microbiota transplantation in neurological disorders.
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Affiliation(s)
| | | | - Reza Jafarzadeh-Esfehani
- Blood Borne Infectious Research Center, Academic Center for Education, Culture and Research (ACECR)-Khorasan Razavi, Mashhad, Iran
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Saman Soleimanpour
- Antimicrobial Resistance Research Centre, Bu-Ali Research Institute, Mashhad University of Medical Sciences, Mashhad, Iran
- Department of Microbiology and Virology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Metabolic Syndrome Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
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14
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Sian-Hülsmann J. Wilful pathogens provoke a gut feeling in Parkinson’s disease. J Neural Transm (Vienna) 2021; 129:557-562. [PMID: 34923593 PMCID: PMC8684782 DOI: 10.1007/s00702-021-02448-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 11/24/2021] [Indexed: 12/17/2022]
Abstract
Parkinson’s disease is the second most common neurological disorder marked by characteristic poverty and dysfunction in movement. There are many mechanisms and factors which have been postulated to be associated with the neurodegenerative pathway(s) resulting in distinctive loss of neurons in the substantia nigra. Subsequently, the neuropathology is more widespread and exhibited in other areas of the brain, and enteric nervous system. Aggregates of misfolded α-synuclein or Lewy bodies are the hallmark of the illness and appear to be central in the whole cascade of cell destruction. There are many processes implicated in neuronal destruction including: oxidative stress, excitotoxicity, mitochondrial dysfunction, an imbalance in protein homeostasis and neuroinflammation. Interesting, inflammation induced by pathogens (including, bacteria and viruses) has been associated in the pathogenesis of the disease. Bacteria such as Helicobacter pylori and Helicobacter suis appear to colonise the gut, and elicit systemic immune responses, which is them transmitted via the gut-axis to the brain, where cytotoxic cytokines induce neuroinflammation and cell death. This conforms to the bottom–top hypothesis proposed by Braak. The gut is also implicated in two other theories postulated in the development and progression of the disorder, namely, the top–down and the threshold. There is a possibility that these theories may be inter-linked and operate together to certain degree. Ultimately specific trigger factors or conditions may govern the occurrences of these processes in genetically predisposed individuals. Nevertheless, the importance of pathogen-related gut infections cannot be overlooked, since it can result in dysbiosis of gut microbes, which may orchestrate α-synuclein pathology and eventually cell destruction.
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Affiliation(s)
- Jeswinder Sian-Hülsmann
- Department of Medical Physiology, University of Nairobi, P.O. Box 30197, Nairobi, 00100, Kenya.
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15
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Zheng SY, Li HX, Xu RC, Miao WT, Dai MY, Ding ST, Liu HD. Potential roles of gut microbiota and microbial metabolites in Parkinson's disease. Ageing Res Rev 2021; 69:101347. [PMID: 33905953 DOI: 10.1016/j.arr.2021.101347] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 04/06/2021] [Accepted: 04/22/2021] [Indexed: 02/07/2023]
Abstract
Parkinson's disease (PD) is a complicated neurodegenerative disease attributed to multifactorial changes. However, its pathological mechanism remains undetermined. Accumulating evidence has revealed the emerging functions of gut microbiota and microbial metabolites, which can affect both the enteric nervous system and the central nervous system via the microbiota-gut-brain axis. Accordingly, intestinal dysbiosis might be closely associated with PD. This review explores alterations to gut microbiota, correlations with clinical manifestations of PD, and briefly probes the underlying mechanisms. Next, the highly controversial roles of microbial metabolites including short-chain fatty acids (SCFAs), H2 and H2S are discussed. Finally, the pros and cons of the current treatments for PD, including those targeting microbiota, are assessed. Advancements in research techniques, further studies on levels of specific strains and longitudinal prospective clinical trials are urgently needed for the identification of early diagnostic markers and the development of novel therapeutic approaches for PD.
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16
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Van Den Berge N, Ferreira N, Mikkelsen TW, Alstrup AKO, Tamgüney G, Karlsson P, Terkelsen AJ, Nyengaard JR, Jensen PH, Borghammer P. Ageing promotes pathological alpha-synuclein propagation and autonomic dysfunction in wild-type rats. Brain 2021; 144:1853-1868. [PMID: 33880502 PMCID: PMC8320301 DOI: 10.1093/brain/awab061] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 11/13/2020] [Accepted: 12/10/2020] [Indexed: 12/16/2022] Open
Abstract
Neuronal aggregates of misfolded alpha-synuclein protein are found in the brain and periphery of patients with Parkinson's disease. Braak and colleagues have hypothesized that the initial formation of misfolded alpha-synuclein may start in the gut, and then spread to the brain via peripheral autonomic nerves hereby affecting several organs, including the heart and intestine. Age is considered the greatest risk factor for Parkinson's disease, but the effect of age on the formation of pathology and its propagation has not been studied in detail. We aimed to investigate whether propagation of alpha-synuclein pathology from the gut to the brain is more efficient in old versus young wild-type rats, upon gastrointestinal injection of aggregated alpha-synuclein. Our results demonstrate a robust age-dependent gut-to-brain and brain-to-gut spread of alpha-synuclein pathology along the sympathetic and parasympathetic nerves, resulting in age-dependent dysfunction of the heart and stomach, as observed in patients with Parkinson's disease. Moreover, alpha-synuclein pathology is more densely packed and resistant to enzymatic digestion in old rats, indicating an age-dependent maturation of alpha-synuclein aggregates. Our study is the first to provide a detailed investigation of alpha-synuclein pathology in several organs within one animal model, including the brain, skin, heart, intestine, spinal cord and autonomic ganglia. Taken together, our findings suggest that age is a crucial factor for alpha-synuclein aggregation and complete propagation to heart, stomach and skin, similar to patients. Given that age is the greatest risk factor for human Parkinson's disease, it seems likely that older experimental animals will yield the most relevant and reliable findings. These results have important implications for future research to optimize diagnostics and therapeutics in Parkinson's disease and other age-associated synucleinopathies. Increased emphasis should be placed on using aged animals in preclinical studies and to elucidate the nature of age-dependent interactions.
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Affiliation(s)
- Nathalie Van Den Berge
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Nelson Ferreira
- DANDRITE-Danish Research Institute of Translational Neuroscience and Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Aage Kristian Olsen Alstrup
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Gültekin Tamgüney
- Institute of Physical Biology, Heinrich-Heine-University, Düsseldorf, Germany
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Páll Karlsson
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Clinical Medicine, The Danish Pain Research Center, Aarhus University, Aarhus, Denmark
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Astrid Juhl Terkelsen
- Department of Clinical Medicine, The Danish Pain Research Center, Aarhus University, Aarhus, Denmark
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Jens Randel Nyengaard
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Center for Stochastic Geometry and Advanced Bioimaging, Aarhus University, Aarhus, Denmark
| | - Poul Henning Jensen
- DANDRITE-Danish Research Institute of Translational Neuroscience and Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Per Borghammer
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
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17
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Parkinson's Disease: A Prionopathy? Int J Mol Sci 2021; 22:ijms22158022. [PMID: 34360787 PMCID: PMC8347681 DOI: 10.3390/ijms22158022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/23/2021] [Accepted: 07/24/2021] [Indexed: 12/13/2022] Open
Abstract
The principal pathogenic event in Parkinson's disease is characterized by the conformational change of α-synuclein, which form pathological aggregates of misfolded proteins, and then accumulate in intraneuronal inclusions causing dopaminergic neuronal loss in specific brain regions. Over the last few years, a revolutionary theory has correlated Parkinson's disease and other neurological disorders with a shared mechanism, which determines α-synuclein aggregates and progresses in the host in a prion-like manner. In this review, the main characteristics shared between α-synuclein and prion protein are compared and the cofactors that influence the remodeling of native protein structures and pathogenetic mechanisms underlying neurodegeneration are discussed.
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18
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The Baseline Structure of the Enteric Nervous System and Its Role in Parkinson's Disease. Life (Basel) 2021; 11:life11080732. [PMID: 34440476 PMCID: PMC8400095 DOI: 10.3390/life11080732] [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: 05/30/2021] [Revised: 07/14/2021] [Accepted: 07/20/2021] [Indexed: 12/17/2022] Open
Abstract
The gastrointestinal (GI) tract is provided with a peculiar nervous network, known as the enteric nervous system (ENS), which is dedicated to the fine control of digestive functions. This forms a complex network, which includes several types of neurons, as well as glial cells. Despite extensive studies, a comprehensive classification of these neurons is still lacking. The complexity of ENS is magnified by a multiple control of the central nervous system, and bidirectional communication between various central nervous areas and the gut occurs. This lends substance to the complexity of the microbiota–gut–brain axis, which represents the network governing homeostasis through nervous, endocrine, immune, and metabolic pathways. The present manuscript is dedicated to identifying various neuronal cytotypes belonging to ENS in baseline conditions. The second part of the study provides evidence on how these very same neurons are altered during Parkinson’s disease. In fact, although being defined as a movement disorder, Parkinson’s disease features a number of degenerative alterations, which often anticipate motor symptoms. Among these, the GI tract is often involved, and for this reason, it is important to assess its normal and pathological structure. A deeper knowledge of the ENS is expected to improve the understanding of diagnosis and treatment of Parkinson’s disease.
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19
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Chiocchetti R, Hitrec T, Giancola F, Sadeghinezhad J, Squarcio F, Galiazzo G, Piscitiello E, De Silva M, Cerri M, Amici R, Luppi M. Phosphorylated Tau protein in the myenteric plexus of the ileum and colon of normothermic rats and during synthetic torpor. Cell Tissue Res 2021; 384:287-299. [PMID: 33511469 PMCID: PMC8141491 DOI: 10.1007/s00441-020-03328-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023]
Abstract
Tau protein is of primary importance for neuronal homeostasis and when hyperphosphorylated (PP-Tau), it tends to aggregate in neurofibrillary tangles, as is the case with tauopathies, a class of neurodegenerative disorders. Reversible PP-Tau accumulation occurs in the brain of hibernating rodents and it was recently observed in rats (a non-hibernator) during synthetic torpor (ST), a pharmacological-induced torpor-like condition. To date, the expression of PP-Tau in the rat enteric nervous system (ENS) is still unknown. The present study immunohistochemically investigates the PP-Tau expression in the myenteric plexus of the ileum and colon of normothermic rats (CTRL) and during ST, focusing on the two major subclasses of enteric neurons, i.e., cholinergic and nitrergic.Results showed that both groups of rats expressed PP-Tau, with a significantly increased percentage of PP-Tau immunoreactive (IR) neurons in ST vs. CTRL. In all rats, the majority of PP-Tau-IR neurons were cholinergic. In ST rats, the percentage of PP-Tau-IR neurons expressing a nitrergic phenotype increased, although with no significant differences between groups. In addition, the ileum of ST rats showed a significant decrease in the percentage of nitrergic neurons. In conclusion, our findings suggest an adaptive response of ENS to very low core body temperatures, with changes involving PP-tau expression in enteric neurons, especially the ileal nitrergic subpopulation. In addition, the high presence of PP-Tau in cholinergic neurons, specifically, is very interesting and deserves further investigation. Altogether, these data strengthen the hypothesis of a common cellular mechanism triggered by ST, natural hibernation and tauopathies occurring in ENS neurons.
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Affiliation(s)
- R Chiocchetti
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy.
| | - T Hitrec
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - F Giancola
- Department of Medical and Surgical Sciences, Alma Mater Studiorum-University of Bologna, and St. Orsola-Malpighi Hospital, Bologna, Italy
| | - J Sadeghinezhad
- Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - F Squarcio
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - G Galiazzo
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - E Piscitiello
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - M De Silva
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - M Cerri
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - R Amici
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - M Luppi
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
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20
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Pirazzini C, Azevedo T, Baldelli L, Bartoletti-Stella A, Calandra-Buonaura G, Dal Molin A, Dimitri GM, Doykov I, Gómez-Garre P, Hägg S, Hällqvist J, Halsband C, Heywood W, Jesús S, Jylhävä J, Kwiatkowska KM, Labrador-Espinosa MA, Licari C, Maturo MG, Mengozzi G, Meoni G, Milazzo M, Periñán-Tocino MT, Ravaioli F, Sala C, Sambati L, Schade S, Schreglmann S, Spasov S, Tenori L, Williams D, Xumerle L, Zago E, Bhatia KP, Capellari S, Cortelli P, Garagnani P, Houlden H, Liò P, Luchinat C, Delledonne M, Mills K, Mir P, Mollenhauer B, Nardini C, Pedersen NL, Provini F, Strom S, Trenkwalder C, Turano P, Bacalini MG, Franceschi C. A geroscience approach for Parkinson's disease: Conceptual framework and design of PROPAG-AGEING project. Mech Ageing Dev 2021; 194:111426. [PMID: 33385396 DOI: 10.1016/j.mad.2020.111426] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/07/2020] [Accepted: 12/22/2020] [Indexed: 12/12/2022]
Abstract
Advanced age is the major risk factor for idiopathic Parkinson's disease (PD), but to date the biological relationship between PD and ageing remains elusive. Here we describe the rationale and the design of the H2020 funded project "PROPAG-AGEING", whose aim is to characterize the contribution of the ageing process to PD development. We summarize current evidences that support the existence of a continuum between ageing and PD and justify the use of a Geroscience approach to study PD. We focus in particular on the role of inflammaging, the chronic, low-grade inflammation characteristic of elderly physiology, which can propagate and transmit both locally and systemically. We then describe PROPAG-AGEING design, which is based on the multi-omic characterization of peripheral samples from clinically characterized drug-naïve and advanced PD, PD discordant twins, healthy controls and "super-controls", i.e. centenarians, who never showed clinical signs of motor disability, and their offspring. Omic results are then validated in a large number of samples, including in vitro models of dopaminergic neurons and healthy siblings of PD patients, who are at higher risk of developing PD, with the final aim of identifying the molecular perturbations that can deviate the trajectories of healthy ageing towards PD development.
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Affiliation(s)
- Chiara Pirazzini
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Tiago Azevedo
- Department of Computer Science and Technology, University of Cambridge, Cambridge, United Kingdom
| | - Luca Baldelli
- Department of Biomedical and NeuroMotor Sciences (DiBiNeM), University of Bologna, Italy
| | | | - Giovanna Calandra-Buonaura
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy; Department of Biomedical and NeuroMotor Sciences (DiBiNeM), University of Bologna, Italy
| | | | - Giovanna Maria Dimitri
- Department of Computer Science and Technology, University of Cambridge, Cambridge, United Kingdom
| | - Ivan Doykov
- Centre for Inborn Errors of Metabolism, UCL Institute of Child Health, London, United Kingdom
| | - Pilar Gómez-Garre
- Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Unidad de Trastornos del Movimiento, Servicio de Neurología y NeurofisiologíaClínica, Instituto de Biomedicina de Sevilla, Seville, Spain; Centro de Investigación Biomédicaen Red sobreEnfermedades Neurodegenerativas (CIBERNED), Spain
| | - Sara Hägg
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Jenny Hällqvist
- Centre for Inborn Errors of Metabolism, UCL Institute of Child Health, London, United Kingdom
| | - Claire Halsband
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany; Department of Gerontopsychiatry, Rhein-Mosel-Fachklinik, Andernach, Germany
| | - Wendy Heywood
- Centre for Inborn Errors of Metabolism, UCL Institute of Child Health, London, United Kingdom; NIHR Great Ormond Street Biomedical Research Centre, Great Ormond Street Hospital and UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Silvia Jesús
- Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Unidad de Trastornos del Movimiento, Servicio de Neurología y NeurofisiologíaClínica, Instituto de Biomedicina de Sevilla, Seville, Spain; Centro de Investigación Biomédicaen Red sobreEnfermedades Neurodegenerativas (CIBERNED), Spain
| | - Juulia Jylhävä
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | | | - Miguel A Labrador-Espinosa
- Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Unidad de Trastornos del Movimiento, Servicio de Neurología y NeurofisiologíaClínica, Instituto de Biomedicina de Sevilla, Seville, Spain; Centro de Investigación Biomédicaen Red sobreEnfermedades Neurodegenerativas (CIBERNED), Spain
| | - Cristina Licari
- CERM, University of Florence, Sesto Fiorentino, Florence, Italy
| | - Maria Giovanna Maturo
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Giacomo Mengozzi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | | | - Maddalena Milazzo
- Department of Experimental, Diagnostic, and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Maria Teresa Periñán-Tocino
- Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Unidad de Trastornos del Movimiento, Servicio de Neurología y NeurofisiologíaClínica, Instituto de Biomedicina de Sevilla, Seville, Spain; Centro de Investigación Biomédicaen Red sobreEnfermedades Neurodegenerativas (CIBERNED), Spain
| | - Francesco Ravaioli
- Department of Experimental, Diagnostic, and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Claudia Sala
- Department of Physics and Astronomy, University of Bologna, Bologna, Italy
| | - Luisa Sambati
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy; Department of Biomedical and NeuroMotor Sciences (DiBiNeM), University of Bologna, Italy
| | - Sebastian Schade
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | - Sebastian Schreglmann
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Simeon Spasov
- Department of Computer Science and Technology, University of Cambridge, Cambridge, United Kingdom
| | - Leonardo Tenori
- Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), Florence, Italy
| | - Dylan Williams
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | | | | | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Sabina Capellari
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy; Department of Biomedical and NeuroMotor Sciences (DiBiNeM), University of Bologna, Italy
| | - Pietro Cortelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy; Department of Biomedical and NeuroMotor Sciences (DiBiNeM), University of Bologna, Italy
| | - Paolo Garagnani
- Department of Experimental, Diagnostic, and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Henry Houlden
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, United Kingdom
| | - Pietro Liò
- Department of Computer Science and Technology, University of Cambridge, Cambridge, United Kingdom
| | - Claudio Luchinat
- CERM, University of Florence, Sesto Fiorentino, Florence, Italy; Department of Chemistry "Ugo Schiff", University of Florence, Italy
| | | | - Kevin Mills
- Centre for Inborn Errors of Metabolism, UCL Institute of Child Health, London, United Kingdom; NIHR Great Ormond Street Biomedical Research Centre, Great Ormond Street Hospital and UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Pablo Mir
- Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Unidad de Trastornos del Movimiento, Servicio de Neurología y NeurofisiologíaClínica, Instituto de Biomedicina de Sevilla, Seville, Spain; Centro de Investigación Biomédicaen Red sobreEnfermedades Neurodegenerativas (CIBERNED), Spain
| | - Brit Mollenhauer
- Paracelsus-Elena-Klinik, Kassel, Germany; Department of Neurology, University Medical Centre Goettingen, Goettingen, Germany
| | - Christine Nardini
- Istituto per le Applicazioni del Calcolo Mauro Picone, CNR, Roma, Italy
| | - Nancy L Pedersen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Federica Provini
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy; Department of Biomedical and NeuroMotor Sciences (DiBiNeM), University of Bologna, Italy
| | - Stephen Strom
- Department of Laboratory Medicine, Karolinska Institute and Karolinska Universitetssjukhuset, 171 76, Stockholm, Sweden
| | - Claudia Trenkwalder
- Paracelsus-Elena-Klinik, Kassel, Germany; Department of Neurosurgery, University Medical Center Göttingen, Germany
| | - Paola Turano
- CERM, University of Florence, Sesto Fiorentino, Florence, Italy; Department of Chemistry "Ugo Schiff", University of Florence, Italy
| | | | - Claudio Franceschi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy; Laboratory of Systems Medicine of Healthy Aging and Department of Applied Mathematics, Lobachevsky University, Nizhny Novgorod, Russia
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21
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Derkinderen P, Rolli-Derkinderen M, Chapelet G, Neunlist M, Noble W. Tau in the gut, does it really matter? J Neurochem 2021; 158:94-104. [PMID: 33569813 DOI: 10.1111/jnc.15320] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 12/11/2022]
Abstract
The enteric nervous system plays a critical role in the regulation of gastrointestinal tract functions and is often referred to as the 'second brain' because it shares many features with the central nervous system. These similarities include among others a large panel of neurotransmitters, a large population of glial cells and a susceptibility to neurodegeneration. This close homology between the central and enteric nervous systems suggests that a disease process affecting the central nervous system could also involve its enteric counterpart. This was already documented in Parkinson's disease, the most common synucleinopathy, in which alpha-synuclein deposits are reported in the enteric nervous system in the vast majority of patients. Tau is another key protein involved in neurodegenerative disorders of the brain. Whether changes in tau also occur in the enteric nervous system during gut or brain disorders has just begun to be explored. The scope of the present article is therefore to review existing studies on the expression and phosphorylation pattern of tau in the enteric nervous system under physiological and pathological conditions and to discuss the possible occurrence of 'enteric tauopathies'.
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Affiliation(s)
- Pascal Derkinderen
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France.,Department of Neurology, CHU Nantes, Nantes, France
| | - Malvyne Rolli-Derkinderen
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Guillaume Chapelet
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France.,Clinical Gerontology Department, CHU Nantes, Nantes, France
| | - Michel Neunlist
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Wendy Noble
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
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22
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Gentile F, Doneddu PE, Riva N, Nobile-Orazio E, Quattrini A. Diet, Microbiota and Brain Health: Unraveling the Network Intersecting Metabolism and Neurodegeneration. Int J Mol Sci 2020; 21:E7471. [PMID: 33050475 PMCID: PMC7590163 DOI: 10.3390/ijms21207471] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 02/06/2023] Open
Abstract
Increasing evidence gives support for the idea that extra-neuronal factors may affect brain physiology and its predisposition to neurodegenerative diseases. Epidemiological and experimental studies show that nutrition and metabolic disorders such as obesity and type 2 diabetes increase the risk of Alzheimer's and Parkinson's diseases after midlife, while the relationship with amyotrophic lateral sclerosis is uncertain, but suggests a protective effect of features of metabolic syndrome. The microbiota has recently emerged as a novel factor engaging strong interactions with neurons and glia, deeply affecting their function and behavior in these diseases. In particular, recent evidence suggested that gut microbes are involved in the seeding of prion-like proteins and their spreading to the central nervous system. Here, we present a comprehensive review of the impact of metabolism, diet and microbiota in neurodegeneration, by affecting simultaneously several aspects of health regarding energy metabolism, immune system and neuronal function. Advancing technologies may allow researchers in the future to improve investigations in these fields, allowing the buildup of population-based preventive interventions and development of targeted therapeutics to halt progressive neurologic disability.
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Affiliation(s)
- Francesco Gentile
- Experimental Neuropathology Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy; (F.G.); (N.R.)
- Neuromuscular and Neuroimmunology Service, Humanitas Clinical and Research Institute IRCCS, 20089 Milan, Italy; (P.E.D.); (E.N.-O.)
| | - Pietro Emiliano Doneddu
- Neuromuscular and Neuroimmunology Service, Humanitas Clinical and Research Institute IRCCS, 20089 Milan, Italy; (P.E.D.); (E.N.-O.)
| | - Nilo Riva
- Experimental Neuropathology Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy; (F.G.); (N.R.)
- Department of Neurology, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Eduardo Nobile-Orazio
- Neuromuscular and Neuroimmunology Service, Humanitas Clinical and Research Institute IRCCS, 20089 Milan, Italy; (P.E.D.); (E.N.-O.)
- Department of Medical Biotechnology and Translational Medicine, University of Milan, 20122 Milan, Italy
| | - Angelo Quattrini
- Experimental Neuropathology Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy; (F.G.); (N.R.)
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23
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Borghammer P, Van Den Berge N. Brain-First versus Gut-First Parkinson's Disease: A Hypothesis. JOURNAL OF PARKINSONS DISEASE 2020; 9:S281-S295. [PMID: 31498132 PMCID: PMC6839496 DOI: 10.3233/jpd-191721] [Citation(s) in RCA: 185] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Parkinson’s disease (PD) is a highly heterogeneous disorder, which probably consists of multiple subtypes. Aggregation of misfolded alpha-synuclein and propagation of these proteinacious aggregates through interconnected neural networks is believed to be a crucial pathogenetic factor. It has been hypothesized that the initial pathological alpha-synuclein aggregates originate in the enteric or peripheral nervous system (PNS) and invade the central nervous system (CNS) via retrograde vagal transport. However, evidence from neuropathological studies suggests that not all PD patients can be reconciled with this hypothesis. Importantly, a small fraction of patients do not show pathology in the dorsal motor nucleus of the vagus. Here, it is hypothesized that PD can be divided into a PNS-first and a CNS-first subtype. The former is tightly associated with REM sleep behavior disorder (RBD) during the prodromal phase and is characterized by marked autonomic damage before involvement of the dopaminergic system. In contrast, the CNS-first phenotype is most often RBD-negative during the prodromal phase and characterized by nigrostriatal dopaminergic dysfunction prior to involvement of the autonomic PNS. The existence of these subtypes is supported by in vivo imaging studies of RBD-positive and RBD-negative patient groups and by histological evidence— reviewed herein. The present proposal provides a fresh hypothesis-generating framework for future studies into the etiopathogenesis of PD and seems capable of explaining a number of discrepant findings in the neuropathological literature.
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Affiliation(s)
- Per Borghammer
- Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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24
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Miraglia F, Colla E. Microbiome, Parkinson's Disease and Molecular Mimicry. Cells 2019; 8:E222. [PMID: 30866550 PMCID: PMC6468760 DOI: 10.3390/cells8030222] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/04/2019] [Accepted: 03/05/2019] [Indexed: 12/30/2022] Open
Abstract
Parkinson's Disease (PD) is typically classified as a neurodegenerative disease affecting the motor system. Recent evidence, however, has uncovered the presence of Lewy bodies in locations outside the CNS, in direct contact with the external environment, including the olfactory bulbs and the enteric nervous system. This, combined with the ability of alpha-synuclein (αS) to propagate in a prion-like manner, has supported the hypothesis that the resident microbial community, commonly referred to as microbiota, might play a causative role in the development of PD. In this article, we will be reviewing current knowledge on the importance of the microbiota in PD pathology, concentrating our investigation on mechanisms of microbiota-host interactions that might become harmful and favor the onset of PD. Such processes, which include the secretion of bacterial amyloid proteins or other metabolites, may influence the aggregation propensity of αS directly or indirectly, for example by favoring a pro-inflammatory environment in the gut. Thus, while the development of PD has not yet being associated with a unique microbial species, more data will be necessary to examine potential harmful interactions between the microbiota and the host, and to understand their relevance in PD pathogenesis.
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Affiliation(s)
- Fabiana Miraglia
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy.
- Bio@SNS Laboratory, Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
| | - Emanuela Colla
- Bio@SNS Laboratory, Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
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25
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Breen DP, Halliday GM, Lang AE. Gut-brain axis and the spread of α-synuclein pathology: Vagal highway or dead end? Mov Disord 2019; 34:307-316. [PMID: 30653258 DOI: 10.1002/mds.27556] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 08/06/2018] [Accepted: 10/08/2018] [Indexed: 12/11/2022] Open
Abstract
Spread of α-synuclein pathology from the peripheral to central nervous system may be an important etiological factor in Parkinson's disease, although there are some unanswered questions about its correlation with neuronal loss. Experimental evidence has highlighted the gastrointestinal tract as a potential starting point for aggregated α-synuclein, with the vagus nerve acting as a "highway" by which pathology may be transmitted to the lower brain stem. This review begins by highlighting the key studies demonstrating that α-synuclein pathology has the ability to spread from certain sites in the gastrointestinal tract to the brain (and vice versa). We go on to assess the recent epidemiological studies that have shown that vagotomy and appendectomy may have the potential to reduce the risk of developing Parkinson's disease. Finally, we discuss the factors in the gastrointestinal tract (such as dysbiosis of the gut microbiota, infection, and inflammation) that may trigger α-synuclein aggregation in the first place, as well as other potential mechanisms underlying the distribution of α-synuclein pathology in the brain. © 2019 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- David P Breen
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland
- Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, Edinburgh, Scotland
- Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Edinburgh, Scotland
| | - Glenda M Halliday
- Brain and Mind Centre, Sydney Medical School, University of Sydney, Camperdown, Australia
- School of Medical Sciences, University of New South Wales, Kensington, Australia
- Neuroscience Research Australia, Randwick, Australia
| | - Anthony E Lang
- Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, Toronto, Canada
- Krembil Research Institute, Toronto Western Hospital, Toronto, Canada
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26
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Lionnet A, Wade MA, Corbillé AG, Prigent A, Paillusson S, Tasselli M, Gonzales J, Durieu E, Rolli-Derkinderen M, Coron E, Duchalais E, Neunlist M, Perkinton MS, Hanger DP, Noble W, Derkinderen P. Characterisation of tau in the human and rodent enteric nervous system under physiological conditions and in tauopathy. Acta Neuropathol Commun 2018; 6:65. [PMID: 30037345 PMCID: PMC6055332 DOI: 10.1186/s40478-018-0568-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 07/06/2018] [Indexed: 12/30/2022] Open
Abstract
Tau is normally a highly soluble phosphoprotein found predominantly in neurons. Six different isoforms of tau are expressed in the adult human CNS. Under pathological conditions, phosphorylated tau aggregates are a defining feature of neurodegenerative disorders called tauopathies. Recent findings have suggested a potential role of the gut-brain axis in CNS homeostasis, and therefore we set out to examine the isoform profile and phosphorylation state of tau in the enteric nervous system (ENS) under physiological conditions and in tauopathies. Surgical specimens of human colon from controls, Parkinson's disease (PD) and progressive supranuclear palsy (PSP) patients were analyzed by Western Blot and immunohistochemistry using a panel of anti-tau antibodies. We found that adult human ENS primarily expresses two tau isoforms, localized in the cell bodies and neuronal processes. We did not observe any difference in the enteric tau isoform profile and phosphorylation state between PSP, PD and control subjects. The htau mouse model of tauopathy also expressed two main isoforms of human tau in the ENS, and there were no apparent differences in ENS tau localization or phosphorylation between wild-type and htau mice. Tau in both human and mouse ENS was found to be phosphorylated but poorly susceptible to dephosphorylation with lambda phosphatase. To investigate ENS tau phosphorylation further, primary cultures from rat enteric neurons, which express four isoforms of tau, were pharmacologically manipulated to show that ENS tau phosphorylation state can be regulated, at least in vitro. Our study is the first to characterize tau in the rodent and human ENS. As a whole, our findings provide a basis to unravel the functions of tau in the ENS and to further investigate the possibility of pathological changes in enteric neuropathies and tauopathies.
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27
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Ribaldone DG, Pellicano R, Actis GC. Inflammation: a highly conserved, Janus-like phenomenon—a gastroenterologist’ perspective. J Mol Med (Berl) 2018; 96:861-871. [DOI: 10.1007/s00109-018-1668-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 06/10/2018] [Accepted: 07/04/2018] [Indexed: 12/12/2022]
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28
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Nagpal R, Mainali R, Ahmadi S, Wang S, Singh R, Kavanagh K, Kitzman DW, Kushugulova A, Marotta F, Yadav H. Gut microbiome and aging: Physiological and mechanistic insights. NUTRITION AND HEALTHY AGING 2018; 4:267-285. [PMID: 29951588 PMCID: PMC6004897 DOI: 10.3233/nha-170030] [Citation(s) in RCA: 372] [Impact Index Per Article: 62.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The development of human gut microbiota begins as soon as the neonate leaves the protective environment of the uterus (or maybe in-utero) and is exposed to innumerable microorganisms from the mother as well as the surrounding environment. Concurrently, the host responses to these microbes during early life manifest during the development of an otherwise hitherto immature immune system. The human gut microbiome, which comprises an extremely diverse and complex community of microorganisms inhabiting the intestinal tract, keeps on fluctuating during different stages of life. While these deviations are largely natural, inevitable and benign, recent studies show that unsolicited perturbations in gut microbiota configuration could have strong impact on several features of host health and disease. Our microbiota undergoes the most prominent deviations during infancy and old age and, interestingly, our immune health is also in its weakest and most unstable state during these two critical stages of life, indicating that our microbiota and health develop and age hand-in-hand. However, the mechanisms underlying these interactions are only now beginning to be revealed. The present review summarizes the evidences related to the age-associated changes in intestinal microbiota and vice-versa, mechanisms involved in this bi-directional relationship, and the prospective for development of microbiota-based interventions such as probiotics for healthy aging.
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Affiliation(s)
- Ravinder Nagpal
- Center for Obesity, Diabetes and Metabolism (Internal Medicine-Molecular Medicine), Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Rabina Mainali
- Center for Obesity, Diabetes and Metabolism (Internal Medicine-Molecular Medicine), Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Shokouh Ahmadi
- Center for Obesity, Diabetes and Metabolism (Internal Medicine-Molecular Medicine), Wake Forest School of Medicine, Winston-Salem, NC, USA
- Department of Food Science and Technology, College of Agriculture, Isfahan University of Technology, Isfahan, Iran
| | - Shaohua Wang
- Center for Obesity, Diabetes and Metabolism (Internal Medicine-Molecular Medicine), Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Ria Singh
- Center for Obesity, Diabetes and Metabolism (Internal Medicine-Molecular Medicine), Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Kylie Kavanagh
- Department of Pathology (Comparative Medicine), Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Dalane W. Kitzman
- Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Almagul Kushugulova
- Center for Life Sciences, NLA, Nazarbayev University, Astana, Republic of Kazakhstan
| | - Francesco Marotta
- ReGenera Research and Development for Aging Interventions, and San Babila Clinic, Corso Matteotti 1/A, Milano, Italy
| | - Hariom Yadav
- Center for Obesity, Diabetes and Metabolism (Internal Medicine-Molecular Medicine), Wake Forest School of Medicine, Winston-Salem, NC, USA
- Corresponding author: Hariom Yadav, PhD., Center for Diabetes, Obesity and Metabolism (Internal Medicine-Molecular Medicine), Wake Forest School of Medicine, Department of Microbiology and Immunology, Biotech Place, Suite 2E-034, 575 Patterson Ave., Winston-Salem, NC 27101, USA. Tel.: +1 336 713 5049; Fax: +1 336 716 9928; E-mail:
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29
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Age-dependent elevations of oligomeric and phosphorylated alpha-synuclein synchronously occurs in the brain and gastrointestinal tract of cynomolgus monkeys. Neurosci Lett 2018; 662:276-282. [DOI: 10.1016/j.neulet.2017.10.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 10/24/2017] [Accepted: 10/24/2017] [Indexed: 11/23/2022]
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30
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Stolzenberg E, Berry D, Yang D, Lee EY, Kroemer A, Kaufman S, Wong GCL, Oppenheim JJ, Sen S, Fishbein T, Bax A, Harris B, Barbut D, Zasloff MA. A Role for Neuronal Alpha-Synuclein in Gastrointestinal Immunity. J Innate Immun 2017. [PMID: 28651250 DOI: 10.1159/000477990] [Citation(s) in RCA: 196] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Alpha-synuclein (αS) is a nerve cell protein associated with Parkinson disease (PD). Accumulation of αS within the enteric nervous system (ENS) and its traffic from the gut to the brain are implicated in the pathogenesis and progression of PD. αS has no known function in humans and the reason for its accumulation within the ENS is unknown. Several recent studies conducted in rodents have linked αS to immune cell activation in the central nervous system. We hypothesized that αS in the ENS might play a role in the innate immune defenses of the human gastrointestinal (GI) tract. METHODS We immunostained endoscopic biopsies for αS from children with documented gastric and duodenal inflammation and intestinal allograft recipients who contracted norovirus. To determine whether αS exhibited immune-modulatory activity, we examined whether human αS induced leukocyte migration and dendritic cell maturation. FINDINGS We showed that the expression of αS in the enteric neurites of the upper GI tract of pediatric patients positively correlated with the degree of acute and chronic inflammation in the intestinal wall. In intestinal allograft subjects who were closely monitored for infection, expression of αS was induced during norovirus infection. We also demonstrated that both monomeric and oligomeric αS have potent chemoattractant activity, causing the migration of neutrophils and monocytes dependent on the presence of the integrin subunit, CD11b, and that both forms of αS stimulate dendritic cell maturation. INTERPRETATION These findings strongly suggest that αS is expressed within the human ENS to direct intestinal inflammation and implicates common GI infections in the pathogenesis of PD.
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Affiliation(s)
- Ethan Stolzenberg
- Department of Pathology, Section of Neuropathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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31
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Exposure to the Functional Bacterial Amyloid Protein Curli Enhances Alpha-Synuclein Aggregation in Aged Fischer 344 Rats and Caenorhabditis elegans. Sci Rep 2016; 6:34477. [PMID: 27708338 PMCID: PMC5052651 DOI: 10.1038/srep34477] [Citation(s) in RCA: 272] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 09/14/2016] [Indexed: 02/08/2023] Open
Abstract
Misfolded alpha-synuclein (AS) and other neurodegenerative disorder proteins display prion-like transmission of protein aggregation. Factors responsible for the initiation of AS aggregation are unknown. To evaluate the role of amyloid proteins made by the microbiota we exposed aged rats and transgenic C. elegans to E. coli producing the extracellular bacterial amyloid protein curli. Rats exposed to curli-producing bacteria displayed increased neuronal AS deposition in both gut and brain and enhanced microgliosis and astrogliosis compared to rats exposed to either mutant bacteria unable to synthesize curli, or to vehicle alone. Animals exposed to curli producing bacteria also had more expression of TLR2, IL-6 and TNF in the brain than the other two groups. There were no differences among the rat groups in survival, body weight, inflammation in the mouth, retina, kidneys or gut epithelia, and circulating cytokine levels. AS-expressing C. elegans fed on curli-producing bacteria also had enhanced AS aggregation. These results suggest that bacterial amyloid functions as a trigger to initiate AS aggregation through cross-seeding and also primes responses of the innate immune system.
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32
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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: 342] [Impact Index Per Article: 42.8] [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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33
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Xuan Q, Zhang YX, Liu DG, Chan P, Xu SL, Cui YQ. Post-translational modifications of α-synuclein contribute to neurodegeneration in the colon of elderly individuals. Mol Med Rep 2016; 13:5077-83. [PMID: 27109489 PMCID: PMC4878562 DOI: 10.3892/mmr.2016.5166] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 02/23/2016] [Indexed: 01/24/2023] Open
Abstract
Synucleinopathies and abnormalities in the nerves of the enteric nervous system are hypothesized to be involved in age-associated motility disorders. The aim of the present study was to investigate the expression of various antigens, including α‑synuclein (Syn) and its post‑translational modified forms, in the human colon at various ages. In addition, the study aimed to correlate the expression of Syn with neurodegeneration. Immunohistochemistry was used to detect the expression of neurofilament (NF), Syn, as well as its nitrated (N) form in the healthy colonic tissue of 12 young (34.08±5.12 years), 10 middle‑aged (51.80±3.52 years), and 11 elderly (75.82±7.70 years) individuals. To the best of our knowledge, the current study is the first to demonstrate the presence of N‑Syn in the colonic tissue. N‑Syn was identified in the upper layer of the mucosa and submucosa layer. Furthermore, Syn (wild‑type) was present in the mucosa and submucosa. The number of NF‑positive neurons in the submucosal layer declined significantly with age (P<0.01). In addition, Syn and N‑Syn significantly increased during aging (P<0.01). Furthermore, a negative correlation was identified between neuron number and synucleinopathies, indicating the abnormal accumulation of both wild-type Syn and N‑Syn in the mucosa, submucosa, muscle layer and myenteric plexus. The present study demonstrates that the Syn pathology may be linked to colic neuronal degeneration during normal aging, and this link may cause functional deficits.
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Affiliation(s)
- Qi Xuan
- Department of Nutrition, Xuanwu Hospital, Capital Medical University, Beijing 100053, P.R. China
| | - Yu-Xian Zhang
- Department of Internal Medicine, Beijing Moslem Hospital, Beijing 100054, P.R. China
| | - Dian-Gang Liu
- Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, P.R. China
| | - Piu Chan
- Department of Neurobiology, Institute of Geriatrics of Beijing, Xuanwu Hospital, Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Beijing 100053, P.R. China
| | - Sheng-Li Xu
- Department of Neurobiology, Institute of Geriatrics of Beijing, Xuanwu Hospital, Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Beijing 100053, P.R. China
| | - Ye-Qing Cui
- Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, P.R. China
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Walter GC, Phillips RJ, McAdams JL, Powley TL. Individual sympathetic postganglionic neurons coinnervate myenteric ganglia and smooth muscle layers in the gastrointestinal tract of the rat. J Comp Neurol 2016; 524:2577-603. [PMID: 26850701 DOI: 10.1002/cne.23978] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 01/21/2016] [Accepted: 02/02/2016] [Indexed: 01/25/2023]
Abstract
A full description of the terminal architecture of sympathetic axons innervating the gastrointestinal (GI) tract has not been available. To label sympathetic fibers projecting to the gut muscle wall, dextran biotin was injected into the celiac and superior mesenteric ganglia (CSMG) of rats. Nine days postinjection, animals were euthanized and stomachs and small intestines were processed as whole mounts (submucosa and mucosa removed) to examine CSMG efferent terminals. Myenteric neurons were counterstained with Cuprolinic Blue; catecholaminergic axons were stained immunohistochemically for tyrosine hydroxylase. Essentially all dextran-labeled axons (135 of 136 sampled) were tyrosine hydroxylase-positive. Complete postganglionic arbors (n = 154) in the muscle wall were digitized and analyzed morphometrically. Individual sympathetic axons formed complex arbors of varicose neurites within myenteric ganglia/primary plexus and, concomitantly, long rectilinear arrays of neurites within circular muscle/secondary plexus or longitudinal muscle/tertiary plexus. Very few CSMG neurons projected exclusively (i.e., ∼100% of an arbor's varicose branches) to myenteric plexus (∼2%) or smooth muscle (∼14%). With less stringent inclusion criteria (i.e., ≥85% of an axon's varicose branches), larger minorities of neurons projected predominantly to either myenteric plexus (∼13%) or smooth muscle (∼27%). The majority (i.e., ∼60%) of all individual CSMG postganglionics formed mixed, heterotypic arbors that coinnervated extensively (>15% of their varicose branches per target) both myenteric ganglia and smooth muscle. The fact that ∼87% of all sympathetics projected either extensively or even predominantly to smooth muscle, while simultaneously contacting myenteric plexus, is consistent with the view that these neurons control GI muscle directly, if not exclusively. J. Comp. Neurol. 524:2577-2603, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Gary C Walter
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Robert J Phillips
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Jennifer L McAdams
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Terry L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, USA
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Keating C, Nocchi L, Yu Y, Donovan J, Grundy D. Ageing and gastrointestinal sensory function: altered colonic mechanosensory and chemosensory function in the aged mouse. J Physiol 2016; 594:4549-64. [PMID: 26592729 PMCID: PMC4983623 DOI: 10.1113/jp271403] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/13/2015] [Indexed: 01/13/2023] Open
Abstract
Key points Remarkably little is known about how age affects the sensory signalling pathways in the gastrointestinal tract despite age‐related gastrointestinal dysfunction being a prime cause of morbidity amongst the elderly population High‐threshold gastrointestinal sensory nerves play a key role in signalling distressing information from the gut to the brain. We found that ageing is associated with attenuated high‐threshold afferent mechanosensitivity in the murine colon, and associated loss of TRPV1 channel function. These units have the capacity to sensitise in response to injurious events, and their loss in ageing may predispose the elderly to lower awareness of GI injury or disease.
Abstract Ageing has a profound effect upon gastrointestinal function through mechanisms that are poorly understood. Here we investigated the effect of age upon gastrointestinal sensory signalling pathways in order to address the mechanisms underlying these changes. In vitro mouse colonic and jejunal preparations with attached splanchnic and mesenteric nerves were used to study mechanosensory and chemosensory afferent function in 3‐, 12‐ and 24‐month‐old C57BL/6 animals. Quantitative RT‐PCR was used to investigate mRNA expression in colonic tissue and dorsal root ganglion (DRG) cells isolated from 3‐ and 24‐month animals, and immunohistochemistry was used to quantify the number of 5‐HT‐expressing enterochromaffin (EC) cells. Colonic and jejunal afferent mechanosensory function was attenuated with age and these effects appeared earlier in the colon compared to the jejunum. Colonic age‐related loss of mechanosensory function was more pronounced in high‐threshold afferents compared to low‐threshold afferents. Chemosensory function was attenuated in the 24‐month colon, affecting TRPV1 and serotonergic signalling pathways. High‐threshold mechanosensory afferent fibres and small‐diameter DRG neurons possessed lower functional TRPV1 receptor responses, which occurred without a change in TRPV1 mRNA expression. Serotonergic signalling was attenuated at 24 months, but TPH1 and TPH2 mRNA expression was elevated in colonic tissue. In conclusion, we saw an age‐associated decrease in afferent mechanosensitivity in the mouse colon affecting HT units. These units have the capacity to sensitise in response to injurious events, and their loss in ageing may predispose the elderly to lower awareness of GI injury or disease. Remarkably little is known about how age affects the sensory signalling pathways in the gastrointestinal tract despite age‐related gastrointestinal dysfunction being a prime cause of morbidity amongst the elderly population High‐threshold gastrointestinal sensory nerves play a key role in signalling distressing information from the gut to the brain. We found that ageing is associated with attenuated high‐threshold afferent mechanosensitivity in the murine colon, and associated loss of TRPV1 channel function. These units have the capacity to sensitise in response to injurious events, and their loss in ageing may predispose the elderly to lower awareness of GI injury or disease.
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Affiliation(s)
- Christopher Keating
- Department of Biomedical Sciences, University of Sheffield, Sheffield, UK.,Department of Pharmacy, Pharmacology and Postgraduate Medicine, University of Hertfordshire, Hatfield, Hertfordshire, UK
| | - Linda Nocchi
- Department of Biomedical Sciences, University of Sheffield, Sheffield, UK
| | - Yang Yu
- Department of Biomedical Sciences, University of Sheffield, Sheffield, UK
| | - Jemma Donovan
- Department of Biomedical Sciences, University of Sheffield, Sheffield, UK
| | - David Grundy
- Department of Biomedical Sciences, University of Sheffield, Sheffield, UK
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Ranson RN, Saffrey MJ. Neurogenic mechanisms in bladder and bowel ageing. Biogerontology 2015; 16:265-84. [PMID: 25666896 PMCID: PMC4361768 DOI: 10.1007/s10522-015-9554-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 01/28/2015] [Indexed: 01/18/2023]
Abstract
The prevalence of both urinary and faecal incontinence, and also chronic constipation, increases with ageing and these conditions have a major impact on the quality of life of the elderly. Management of bladder and bowel dysfunction in the elderly is currently far from ideal and also carries a significant financial burden. Understanding how these changes occur is thus a major priority in biogerontology. The functions of the bladder and terminal bowel are regulated by complex neuronal networks. In particular neurons of the spinal cord and peripheral ganglia play a key role in regulating micturition and defaecation reflexes as well as promoting continence. In this review we discuss the evidence for ageing-induced neuronal dysfunction that might predispose to neurogenic forms of incontinence in the elderly.
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Affiliation(s)
- Richard N Ranson
- Department of Applied Sciences (Biomedical Sciences), Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK,
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Saffrey MJ. Aging of the mammalian gastrointestinal tract: a complex organ system. AGE (DORDRECHT, NETHERLANDS) 2014; 36:9603. [PMID: 24352567 PMCID: PMC4082571 DOI: 10.1007/s11357-013-9603-2] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 11/25/2013] [Indexed: 05/23/2023]
Abstract
Gastrointestinal disorders are a major cause of morbidity in the elderly population. The gastrointestinal tract is the most complex organ system; its diverse cells perform a range of functions essential to life, not only secretion, digestion, absorption and excretion, but also, very importantly, defence. The gastrointestinal tract acts not only as a barrier to harmful materials and pathogens but also contains the vast number of beneficial bacterial populations that make up the microbiota. Communication between the cells of the gastrointestinal tract and the central nervous and endocrine systems modifies behaviour; the organisms of the microbiota also contribute to this brain-gut-enteric microbiota axis. Age-related physiological changes in the gut are not only common, but also variable, and likely to be influenced by external factors as well as intrinsic aging of the cells involved. The cellular and molecular changes exhibited by the aging gut cells also vary. Aging intestinal smooth muscle cells exhibit a number of changes in the signalling pathways that regulate contraction. There is some evidence for age-associated degeneration of neurons and glia of the enteric nervous system, although enteric neuronal losses are likely not to be nearly as extensive as previously believed. Aging enteric neurons have been shown to exhibit a senescence-associated phenotype. Epithelial stem cells exhibit increased mitochondrial mutation in aging that affects their progeny in the mucosal epithelium. Changes to the microbiota and intestinal immune system during aging are likely to contribute to wider aging of the organism and are increasingly important areas of analysis. How changes of the different cell types of the gut during aging affect the numerous cellular interactions that are essential for normal gut functions will be important areas for future aging research.
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Affiliation(s)
- M Jill Saffrey
- Department of Life Health and Chemical Sciences, Biomedical Research Network, The Open University, Milton Keynes, MK7 6AA, UK,
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Phillips RJ, Hudson CN, Powley TL. Sympathetic axonopathies and hyperinnervation in the small intestine smooth muscle of aged Fischer 344 rats. Auton Neurosci 2013; 179:108-21. [PMID: 24104187 DOI: 10.1016/j.autneu.2013.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 09/04/2013] [Accepted: 09/09/2013] [Indexed: 01/13/2023]
Abstract
It is well documented that the intrinsic enteric nervous system of the gastrointestinal (GI) tract sustains neuronal losses and reorganizes as it ages. In contrast, age-related remodeling of the extrinsic sympathetic projections to the wall of the gut is poorly characterized. The present experiment, therefore, surveyed the sympathetic projections to the aged small intestine for axonopathies. Furthermore, the experiment evaluated the specific prediction that catecholaminergic inputs undergo hyperplastic changes. Jejunal tissue was collected from 3-, 8-, 16-, and 24-month-old male Fischer 344 rats, prepared as whole mounts consisting of the muscularis, and processed immunohistochemically for tyrosine hydroxylase, the enzymatic marker for norepinephrine, and either the protein CD163 or the protein MHCII, both phenotypical markers for macrophages. Four distinctive sympathetic axonopathy profiles occurred in the small intestine of the aged rat: (1) swollen and dystrophic terminals, (2) tangled axons, (3) discrete hyperinnervated loci in the smooth muscle wall, including at the bases of Peyer's patches, and (4) ectopic hyperplastic or hyperinnervating axons in the serosa/subserosal layers. In many cases, the axonopathies occurred at localized and limited foci, involving only a few axon terminals, in a pattern consistent with incidences of focal ischemic, vascular, or traumatic insult. The present observations underscore the complexity of the processes of aging on the neural circuitry of the gut, with age-related GI functional impairments likely reflecting a constellation of adjustments that range from selective neuronal losses, through accumulation of cellular debris, to hyperplasias and hyperinnervation of sympathetic inputs.
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Affiliation(s)
- Robert J Phillips
- Purdue University, Department of Psychological Sciences, West Lafayette, IN 47907-2081, United States.
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Alpha-synuclein transmission and mitochondrial toxicity in primary human foetal enteric neurons in vitro. Neurotox Res 2013; 25:170-82. [PMID: 24026637 DOI: 10.1007/s12640-013-9420-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 08/06/2013] [Accepted: 08/17/2013] [Indexed: 01/19/2023]
Abstract
Parkinson's disease (PD) is a multicentred neurodegenerative disorder characterised by the accumulation and aggregation of alpha-synuclein (α-syn) in several parts of the central nervous system. However, it is well established that PD can generate symptoms of constipation and other gastrointestinal problems and α-syn containing lesions have been identified in intestinal nerve cells. In this study, we show that α-syn can be taken up and accumulate in primary human foetal enteric neurons from the gastrointestinal tract and can be transferred between foetal enteric neurons. Impaired proteosomal/lysosomal degradation can promote the uptake and accumulation of α-syn in enteric neurons. Enteric neurons exposed to α-syn can also lead to impaired mitochondrial complex I activity, reduced mitochondrial function, and NAD(+) depletion culminating in cell death via energy restriction. These findings demonstrate neuron-to-neuron transmission of α-syn in enteric neurons, providing renewed evidence for Braak's hypothesis and the aetiology of PD.
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40
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Phillips RJ, Martin FN, Billingsley CN, Powley TL. Alpha-synuclein expression patterns in the colonic submucosal plexus of the aging Fischer 344 rat: implications for biopsies in aging and neurodegenerative disorders? Neurogastroenterol Motil 2013; 25:e621-33. [PMID: 23809578 PMCID: PMC3735646 DOI: 10.1111/nmo.12176] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 06/01/2013] [Indexed: 12/17/2022]
Abstract
BACKGROUND This experiment assessed normative expression patterns of alpha-synuclein (SYNC), including ganglionic remodeling and development of SYNC pathologies, in the submucosal plexus (SMP) of the colon during healthy aging. The observations address age-associated changes in bowel function and are relevant to evaluations of SMP-containing colonic biopsies for SYNC or synucleinopathies associated with aging and peripheral neurodegenerative diseases. METHODS Colonic submucosal whole mounts from groups of virgin male Fischer 344 rats (n ≥ 8 per group) at 4, 8, 16, and 24 months of age were processed immunohistochemically for SYNC and the pan-neuronal marker HuC/D. In addition, macrophages immunoreactive for MHCII were examined. Stereological protocols were used to generate unbiased estimates of neuron density, neurons per ganglion, neurons per ganglionic area, and neuron size. KEY RESULTS The protein SYNC was expressed in a subpopulation of SMP neurons, in both nucleus and cytoplasm. The general age-associated pattern across different cell counts was an increase in the number of SYNC+ neurons between 4 and 8 months of age, with progressively decreasing numbers of both SYNC+ and SYNC- neurons over the remaining lifespan. The soma size of SYNC+ neurons increased progressively with age. Aggregated SYNC occurred in the aging SMP, and macrophages with alternatively activated profiles were located adjacent to pathological SYNC deposits, consistent with ongoing phagocytosis. CONCLUSIONS & INFERENCES Changes in SYNC expression with age, including a baseline of accumulating synucleinopathies in the healthy aging SMP, need to be considered when interpreting either functional disturbances or biopsies of the aging colon.
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Affiliation(s)
- Robert J. Phillips
- Corresponding author: Robert J Phillips Purdue University 703 Third Street West Lafayette, IN 47907-2091 Phone: 765-494-6268 Fax: 765-496-1264
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Gamage PPKM, Ranson RN, Patel BA, Yeoman MS, Saffrey MJ. Myenteric neuron numbers are maintained in aging mouse distal colon. Neurogastroenterol Motil 2013; 25:e495-e505. [PMID: 23517051 DOI: 10.1111/nmo.12114] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 02/15/2013] [Indexed: 12/18/2022]
Abstract
BACKGROUND Age-associated myenteric neuronal loss has been described in several species. In some studies,cholinergic neurons have been reported to be selectively vulnerable, whereas nitrergic neurons are spared. Aging of the mouse enteric nervous system(ENS) and the subtypes of mouse myenteric neurons that may be lost have been little studied. We therefore investigated changes in the numbers of total neurons and two neuronal subpopulations in the mouse distal colon during aging. METHODS Wholemount preparations from 3–4-, 12–13-, 18–19-, and 24–25-month-old C57BL/6 mice were double immunolabeled with HuC/D antibody to identify the total neuronal population and antisera to either calbindin or neuronal nitric oxide synthase (nNOS) to identify myenteric neuronal subpopulations. Samples were analyzed by confocal microscopy. New procedures were employed to ensure unbiased counting and to correct for changes in gut dimensions with age and stretch during sample preparation. The density of nerve fibers in the tertiary plexus was also studied. KEY RESULTS No significant change in numbers of total neurons or of either subpopulation with age was measured, but because of gut growth, the density of myenteric neurons decreased between 3–4 and 12–13 months. The density of nNOS-immunoreactive nerve fibers in the tertiary plexus increased significantly with age, up to 18–19 months. Numerous swollen processes of CB and nNOS-immunoreactive neurons were observed in 18–19- and 24–25-month-old animals. Conclusions &Inferences These results indicate that aging does not result in a loss of myenteric neurons in mouse distal colon at the ages studied, although neurodegenerative changes, which may impact on neuronal function, do occur.
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Affiliation(s)
- P. P. K. M. Gamage
- Department of Life, Health and Chemical Sciences; Biomedical Research Network; Open University; Walton Hall; Milton Keynes; MK7 6AA; UK
| | - R. N. Ranson
- Faculty of Health and Life Sciences; Northumbria University; Ellison Building; Newcastle upon Tyne; NE1 8ST; UK
| | - B. A. Patel
- School of Pharmacy and Biomolecular Sciences, Huxley Building; University of Brighton; Lewes Road; Brighton; BN2 4GJ; UK
| | - M. S. Yeoman
- School of Pharmacy and Biomolecular Sciences, Huxley Building; University of Brighton; Lewes Road; Brighton; BN2 4GJ; UK
| | - M. J. Saffrey
- Department of Life, Health and Chemical Sciences; Biomedical Research Network; Open University; Walton Hall; Milton Keynes; MK7 6AA; UK
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Saffrey MJ. Cellular changes in the enteric nervous system during ageing. Dev Biol 2013; 382:344-55. [PMID: 23537898 DOI: 10.1016/j.ydbio.2013.03.015] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Revised: 02/22/2013] [Accepted: 03/19/2013] [Indexed: 02/06/2023]
Abstract
The intrinsic neurons of the gut, enteric neurons, have an essential role in gastrointestinal functions. The enteric nervous system is plastic and continues to undergo changes throughout life, as the gut grows and responds to dietary and other environmental changes. Detailed analysis of changes in the ENS during ageing suggests that enteric neurons are more vulnerable to age-related degeneration and cell death than neurons in other parts of the nervous system, although there is considerable variation in the extent and time course of age-related enteric neuronal loss reported in different studies. Specific neuronal subpopulations, particularly cholinergic myenteric neurons, may be more vulnerable than others to age-associated loss or damage. Enteric degeneration and other age-related neuronal changes may contribute to gastrointestinal dysfunction that is common in the elderly population. Evidence suggests that caloric restriction protects against age-associated loss of enteric neurons, but recent advances in the understanding of the effects of the microbiota and the complex interactions between enteric ganglion cells, mucosal immune system and intestinal epithelium indicate that other factors may well influence ageing of enteric neurons. Much remains to be understood about the mechanisms of neuronal loss and damage in the gut, although there is evidence that reactive oxygen species, neurotrophic factor dysregulation and/or activation of a senescence associated phenotype may be involved. To date, there is no evidence for ongoing neurogenesis that might replace dying neurons in the ageing gut, although small local sites of neurogenesis would be difficult to detect. Finally, despite the considerable evidence for enteric neurodegeneration during ageing, and evidence for some physiological changes in animal models, the ageing gut appears to maintain its function remarkably well in animals that exhibit major neuronal loss, indicating that the ENS has considerable functional reserve.
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Affiliation(s)
- M Jill Saffrey
- Department Life, Health & Chemical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom.
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Phillips RJ, Billingsley CN, Powley TL. Macrophages are unsuccessful in clearing aggregated alpha-synuclein from the gastrointestinal tract of healthy aged Fischer 344 rats. Anat Rec (Hoboken) 2013; 296:654-69. [PMID: 23441091 DOI: 10.1002/ar.22675] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 11/16/2012] [Indexed: 12/20/2022]
Abstract
With age, alpha-synuclein (α-SYNC) misfolds and forms insoluble deposits of protein in the myenteric plexus, leading presumably to dystrophy and degeneration in the circuitry controlling gastrointestinal (GI) function. The present experiment examined aggregates of α-SYNC in the aging small intestine and investigated how macrophages in the wall of the GI tract respond to these aberrant deposits. Groups of adult and aged Fisher 344 rats were studied. Whole mounts of duodenal, jejunal, and ileal smooth muscle wall, including the myenteric plexus, were prepared. Double labeling immunohistochemistry was used to stain α-SYNC protein and the phenotypic macrophage antigens CD163 and MHCII. Alpha-synuclein accumulated in dense aggregates in axons of both postganglionic and preganglionic neurons throughout the small intestine. Staining patterns suggested that deposits of protein occur initially in axonal terminals and then spread retrogradely toward the somata. Macrophages that were adjacent to dystrophic terminal processes were swollen and contained vacuoles filled with insoluble α-SYNC, and these macrophages commonly had the phenotype of alternatively activated phagocytes. The present results suggest that macrophages play an active phagocytotic role in removing α-SYNC aggregates that accumulate with age in the neural circuitry of the gut. Our observations further indicate that this housekeeping response does not clear the protein sufficiently to eliminate all synucleinopathies or their precursor aggregates from the healthy aging GI tract. Thus, accumulating deposits of insoluble α-SYNC in the wall of the GI tract may contribute, especially when compounded by disease or inflammation, to the age-associated neuropathies in the gut that compromise GI function.
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Affiliation(s)
- Robert J Phillips
- Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907-2081, USA.
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Hallett PJ, McLean JR, Kartunen A, Langston JW, Isacson O. α-Synuclein overexpressing transgenic mice show internal organ pathology and autonomic deficits. Neurobiol Dis 2012; 47:258-67. [PMID: 22549133 DOI: 10.1016/j.nbd.2012.04.009] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/06/2012] [Accepted: 04/11/2012] [Indexed: 12/22/2022] Open
Abstract
While studying transgenic mice that overexpress human wildtype alpha-synuclein (Thy1-ASO, ASO) for typical brain alpha-synucleinopathy and central nervous system neuropathology, we observed progressive functional changes in the gastrointestinal and other peripheral organs. A more systematic study revealed that the gastrointestinal tract in ASO mice showed severe distension and blockage of the large intestine by 9-12 months of age. Functional assessments demonstrated a reduction in fecal water content and fecal pellet output, and increased whole gut transit time, in ASO mice compared to wildtype littermates, indicative of constipation, a symptom commonly reported by Parkinson's disease (PD) patients. Food intake was increased and body weight was decreased in 12 month old ASO mice, suggestive of metabolic abnormalities. Post-mortem histological analyses showed that human alpha-synuclein protein was robustly expressed in axonal fibers and in occasional cell bodies of the enteric nervous system, and in the heart of ASO mice. Accumulation of proteinase-K insoluble alpha-synuclein, reminiscent of neurodegenerative processes in PD was also observed. The functional and pathological changes we document here in ASO mice could relate to the autonomic deficits also seen in idiopathic and alpha-synuclein-mediated genetic forms of PD. These experimental data provide a foundation for therapeutic modeling of autonomic changes in PD and related alpha-synucleinopathies.
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Affiliation(s)
- Penelope J Hallett
- Center for Neuroregeneration Research, McLean Hospital/Harvard Medical School, Belmont, MA 02478, USA.
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Phillips RJ, Powley TL. Macrophages associated with the intrinsic and extrinsic autonomic innervation of the rat gastrointestinal tract. Auton Neurosci 2012; 169:12-27. [PMID: 22436622 DOI: 10.1016/j.autneu.2012.02.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Revised: 02/22/2012] [Accepted: 02/23/2012] [Indexed: 12/28/2022]
Abstract
Interactions between macrophages and the autonomic innervation of gastrointestinal (GI) tract smooth muscle have received little experimental attention. To better understand this relationship, immunohistochemistry was performed on GI whole mounts from rats at three ages. The phenotypes, morphologies, and distributions of gut macrophages are consistent with the cells performing extensive housekeeping functions in the smooth muscle layers. Specifically, a dense population of macrophages was located throughout the muscle wall where they were distributed among the muscle fibers and along the vasculature. Macrophages were also associated with ganglia and connectives of the myenteric plexus and with the sympathetic innervation. Additionally, these cells were in tight registration with the dendrites and axons of the myenteric neurons as well as the varicosities along the length of the sympathetic axons, suggestive of a contribution by the macrophages to the homeostasis of both synapses and contacts between the various elements of the enteric circuitry. Similarly, macrophages were involved in the presumed elimination of neuropathies as indicated by their association with dystrophic neurons and neurites which are located throughout the myenteric plexus and smooth muscle wall of aged rats. Importantly, the patterns of macrophage-neuron interactions in the gut paralleled the much more extensively characterized interactions of macrophages (i.e., microglia) and neurons in the CNS. The present observations in the PNS as well as extrapolations from homologous microglia in the CNS suggest that GI macrophages play significant roles in maintaining the nervous system of the gut in the face of wear and tear, disease, and aging.
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Affiliation(s)
- Robert J Phillips
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana 47907-2081, USA
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Lee HJ, Suk JE, Lee KW, Park SH, Blumbergs PC, Gai WP, Lee SJ. Transmission of Synucleinopathies in the Enteric Nervous System of A53T Alpha-Synuclein Transgenic Mice. Exp Neurobiol 2011; 20:181-8. [PMID: 22355263 PMCID: PMC3268152 DOI: 10.5607/en.2011.20.4.181] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 11/28/2011] [Indexed: 01/29/2023] Open
Abstract
Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are characterized by abnormal deposition of α-synuclein aggregates in many regions of the central and peripheral nervous systems. Accumulating evidence suggests that the α-synuclein pathology initiates in a few discrete regions and spreads to larger areas in the nervous system. Recent pathological studies of PD patients have raised the possibility that the enteric nervous system is one of the initial sites of α-synuclein aggregation and propagation. Here, we evaluated the induction and propagation of α-synuclein aggregates in the enteric nervous system of the A53T α-synuclein transgenic mice after injection of human brain tissue extracts into the gastric walls of the mice. Western analysis of the brain extracts showed that the DLB extract contained detergent-stable α-synuclein aggregates, but the normal brain extract did not. Injection of the DLB extract resulted in an increased deposition of α-synuclein in the myenteric neurons, in which α-synuclein formed punctate aggregates over time up to 4 months. In these mice, inflammatory responses were increased transiently at early time points. None of these changes were observed in the A53T mice injected with saline or the normal brain extract, nor were these found in the wild type mice injected with the DLB extract. These results demonstrate that pathological α-synuclein aggregates present in the brain of DLB patient can induce the aggregation of endogenous α-synuclein in the myenteric neurons in A53T mice, suggesting the transmission of synucleinopathy lesions in the enteric nervous system.
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Affiliation(s)
- He-Jin Lee
- Department of Anatomy, School of Medicine, Konkuk University, Seoul 143-701, Korea
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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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48
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Pathological correlates of gastrointestinal dysfunction in Parkinson's disease. Neurobiol Dis 2011; 46:559-64. [PMID: 22048068 DOI: 10.1016/j.nbd.2011.10.014] [Citation(s) in RCA: 185] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 10/11/2011] [Accepted: 10/16/2011] [Indexed: 12/11/2022] Open
Abstract
Gastrointestinal dysfunction is a prominent manifestation of Parkinson's disease (PD). Gastrointestinal symptoms in PD include reduced salivation, dysphagia, impaired gastric emptying, constipation, and defecatory dysfunction. Constipation may precede the development of somatic motor symptoms of PD for several years. Neuropathological studies show early accumulation of abnormal alpha-synuclein (α-SYN) containing inclusions (Lewy neurites) in the enteric nervous system (ENS) and dorsal motor nucleus of the vagus (DMV) both in PD and in incidental Lewy body disease (ILBD). These findings provided the basis for the hypothesis that α-SYN pathology progresses in a centripetal, prion-like fashion, from the ENS to the DMV and then to more rostral areas of the central nervous system. Colonic biopsies may show accumulation α-SYN immunoreactive Lewy neurites in the submucosal plexus of PD patients. Salivary gland involvement is prominent in PD and α-SYN pathology can be detected both at autopsy and in minor salivary gland biopsies.
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49
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Zhou Z, Kim J, Insolera R, Peng X, Fink DJ, Mata M. Rho GTPase regulation of α-synuclein and VMAT2: implications for pathogenesis of Parkinson's disease. Mol Cell Neurosci 2011; 48:29-37. [PMID: 21699982 PMCID: PMC3163163 DOI: 10.1016/j.mcn.2011.06.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 05/06/2011] [Accepted: 06/01/2011] [Indexed: 12/15/2022] Open
Abstract
Accumulation of α-synuclein (Asyn) in neuronal perikarya and dystrophic neurites is characteristic of idiopathic and familial Parkinson's disease. In this study, we investigated the relationship between α-synuclein expression and neurite outgrowth-maturation using MN9D dopaminergic cells and demonstrated key features of Asyn regulation in hippocampal neurons. Neurite elongation elicited by inhibition of Rho GTPase activity with C3 transferase or by db-cAMP treatment was associated with marked reduction of α-synuclein mRNA and protein expression. Rho inhibition resulted in reduction of transcription factor SRF in the nuclear fraction and retention of MKL-1 - the SRF co-transactivator of SRE - in cytosol, indicating that these effects of Rho inhibition may be mediated though reduction of SRF-SRE transcription. Inhibition of Rho GTPase activity led to decreased nuclear localization of GATA2, a key regulator of α-synuclein promoter activity. Rho inhibition-induced neurite extension was associated with increased VMAT2 and SNARE proteins synaptophysin and synapsin I. These results indicate that in the MN9D dopaminergic cell line, α-synuclein transcription and levels of synaptic vesicle associated proteins are inversely correlated with neurite growth. We confirm that in mature hippocampal neurons inhibition of RhoA and knock down of SRF by siRNA also lead to decrease GATA2 and Asyn. The results suggest that RhoA signaling may be potential therapeutic target for the treatment of synucleinopathies.
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Affiliation(s)
- Zhigang Zhou
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
| | - Jeeyong Kim
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
| | - Ryan Insolera
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
| | - Xiangmin Peng
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
| | - David J. Fink
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
| | - Marina Mata
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
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Bitar K, Greenwood-Van Meerveld B, Saad R, Wiley JW. Aging and gastrointestinal neuromuscular function: insights from within and outside the gut. Neurogastroenterol Motil 2011; 23:490-501. [PMID: 21320236 PMCID: PMC3094479 DOI: 10.1111/j.1365-2982.2011.01678.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Affiliation(s)
- K Bitar
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA Research Administration, VA Medical Center, Oklahoma City, OK, USA
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