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Fabi JP. The connection between gut microbiota and its metabolites with neurodegenerative diseases in humans. Metab Brain Dis 2024; 39:967-984. [PMID: 38848023 DOI: 10.1007/s11011-024-01369-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 06/03/2024] [Indexed: 07/10/2024]
Abstract
The aging of populations is a global phenomenon that follows a possible increase in the incidence of neurodegenerative diseases. Alzheimer's, Parkinson's, Multiple Sclerosis, Amyotrophic Lateral Sclerosis, and Huntington's diseases are some neurodegenerative disorders that aging could initiate or aggravate. Recent research has indicated that intestinal microbiota dysbiosis can trigger metabolism and brain functioning, contributing to the etiopathogenesis of those neurodegenerative diseases. The intestinal microbiota and its metabolites show significant functions in various aspects, such as the immune system modulation (development and maturation), the maintenance of the intestinal barrier integrity, the modulation of neuromuscular functions in the intestine, and the facilitation of essential metabolic processes for both the microbiota and humans. The primary evidence supporting the connection between intestinal microbiota and its metabolites with neurodegenerative diseases are epidemiological observations and animal models experimentation. This paper reviews up-to-date evidence on the correlation between the microbiota-gut-brain axis and neurodegenerative diseases, with a specially focus on gut metabolites. Dysbiosis can increase inflammatory cytokines and bacterial metabolites, altering intestinal and blood-brain barrier permeability and causing neuroinflammation, thus facilitating the pathogenesis of neurodegenerative diseases. Clinical data supporting this evidence still needs to be improved. Most of the works found are descriptive and associated with the presence of phyla or species of bacteria with neurodegenerative diseases. Despite the limitations of recent research, the potential for elucidating clinical questions that have thus far eluded clarification within prevailing pathophysiological frameworks of health and disease is promising through investigation of the interplay between the host and microbiota.
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Affiliation(s)
- João Paulo Fabi
- Department of Food Science and Experimental Nutrition, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, 05508000, SP, Brazil.
- Food and Nutrition Research Center (NAPAN), University of São Paulo, São Paulo, 05508080, SP, Brazil.
- Food Research Center (FoRC), CEPID-FAPESP (Research, Innovation and Dissemination Centers, São Paulo Research Foundation), São Paulo, 05508080, SP, Brazil.
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2
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Bashir B, Alam S, Khandale N, Birla D, Vishwas S, Pandey NK, Gupta G, Paudel KR, Dureja H, Kumar P, Singh TG, Kuppusamy G, Zacconi FC, Pinto TDJA, Dhanasekaran M, Gulati M, Dua K, Singh SK. Opening avenues for treatment of neurodegenerative disease using post-biotics: Breakthroughs and bottlenecks in clinical translation. Ageing Res Rev 2024; 95:102236. [PMID: 38369026 DOI: 10.1016/j.arr.2024.102236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 02/12/2024] [Accepted: 02/14/2024] [Indexed: 02/20/2024]
Abstract
Recent studies have indicated the significant involvement of the gut microbiome in both human physiology and pathology. Additionally, therapeutic interventions based on microbiome approaches have been employed to enhance overall health and address various diseases including aging and neurodegenerative disease (ND). Researchers have explored potential links between these areas, investigating the potential pathogenic or therapeutic effects of intestinal microbiota in diseases. This article provides a summary of established interactions between the gut microbiome and ND. Post-biotic is believed to mediate its neuroprotection by elevating the level of dopamine and reducing the level of α-synuclein in substantia nigra, protecting the loss of dopaminergic neurons, reducing the aggregation of NFT, reducing the deposition of amyloid β peptide plagues and ameliorating motor deficits. Moreover, mediates its neuroprotective activity by inhibiting the inflammatory response (decreasing the expression of TNFα, iNOS expression, free radical formation, overexpression of HIF-1α), apoptosis (i.e. active caspase-3, TNF-α, maintains the level of Bax/Bcl-2 ratio) and promoting BDNF secretion. It is also reported to have good antioxidant activity. This review offers an overview of the latest findings from both preclinical and clinical trials concerning the use of post-biotics in ND.
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Affiliation(s)
- Bushra Bashir
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, India
| | - Shahbaz Alam
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, India
| | - Nikhil Khandale
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, India
| | - Devendra Birla
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, India
| | - Sukriti Vishwas
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, India
| | - Narendra Kumar Pandey
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, India
| | - Gaurav Gupta
- School of Pharmacy, Suresh Gyan Vihar University, Jagatpura, Mahal Road, Jaipur 302017, India; Centre of Medical and Bio-allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates
| | - Keshav Raj Paudel
- Centre of Inflammation, Centenary Institute and University of Technology Sydney, Faculty of Science, School of Life Sciences, Sydney, NSW 2007, Australia
| | - Harish Dureja
- Department of Pharmaceutical Sciences, Maharshi Dayanand University, Rohtak, Haryana 124001, India
| | - Puneet Kumar
- Department of Pharmacology, Central University of Punjab, Ghudda, Punjab, India
| | - Thakur Gurjeet Singh
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab 140401, India
| | - Gowthamarajan Kuppusamy
- Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, Nilgiris, India
| | - Flavia C Zacconi
- Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile; Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile
| | - Terezinha de Jesus Andreoli Pinto
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Professor Lineu Prestes Street, Sao Paulo 05508-000, Brazil
| | - Muralikrishnan Dhanasekaran
- Department of Drug Discovery and Development, Harrison College of Pharmacy, Auburn University Auburn, AL 36849, USA
| | - Monica Gulati
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, India; Faculty of Health, Australian Research Centre in Complementary and Integrative Medicine, University of Technology Sydney, Ultimo, NSW 2007, Australia.
| | - Kamal Dua
- Faculty of Health, Australian Research Centre in Complementary and Integrative Medicine, University of Technology Sydney, Ultimo, NSW 2007, Australia; Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Sachin Kumar Singh
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, India; Faculty of Health, Australian Research Centre in Complementary and Integrative Medicine, University of Technology Sydney, Ultimo, NSW 2007, Australia.
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Higinbotham AS, Kilbane CW. The gastrointestinal tract and Parkinson's disease. Front Cell Infect Microbiol 2024; 13:1158986. [PMID: 38292855 PMCID: PMC10825967 DOI: 10.3389/fcimb.2023.1158986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 12/14/2023] [Indexed: 02/01/2024] Open
Affiliation(s)
- Alissa S. Higinbotham
- Parkinson's disease and Movement Disorders Center, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
- Department of Neurology, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Camilla W. Kilbane
- Parkinson's disease and Movement Disorders Center, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
- Department of Neurology, Case Western Reserve University School of Medicine, Cleveland, OH, United States
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Manjarres Z, Calvo M, Pacheco R. Regulation of Pain Perception by Microbiota in Parkinson Disease. Pharmacol Rev 2023; 76:7-36. [PMID: 37863655 DOI: 10.1124/pharmrev.122.000674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 10/03/2023] [Accepted: 10/10/2023] [Indexed: 10/22/2023] Open
Abstract
Pain perception involves current stimulation in peripheral nociceptive nerves and the subsequent stimulation of postsynaptic excitatory neurons in the spinal cord. Importantly, in chronic pain, the neural activity of both peripheral nociceptors and postsynaptic neurons in the central nervous system is influenced by several inflammatory mediators produced by the immune system. Growing evidence has indicated that the commensal microbiota plays an active role in regulating pain perception by either acting directly on nociceptors or indirectly through the modulation of the inflammatory activity on immune cells. This symbiotic relationship is mediated by soluble bacterial mediators or intrinsic structural components of bacteria that act on eukaryotic cells, including neurons, microglia, astrocytes, macrophages, T cells, enterochromaffin cells, and enteric glial cells. The molecular mechanisms involve bacterial molecules that act directly on neurons, affecting their excitability, or indirectly on non-neuronal cells, inducing changes in the production of proinflammatory or anti-inflammatory mediators. Importantly, Parkinson disease, a neurodegenerative and inflammatory disorder that affects mainly the dopaminergic neurons implicated in the control of voluntary movements, involves not only a motor decline but also nonmotor symptomatology, including chronic pain. Of note, several recent studies have shown that Parkinson disease involves a dysbiosis in the composition of the gut microbiota. In this review, we first summarize, integrate, and classify the molecular mechanisms implicated in the microbiota-mediated regulation of chronic pain. Second, we analyze the changes on the commensal microbiota associated to Parkinson disease and propose how these changes affect the development of chronic pain in this pathology. SIGNIFICANCE STATEMENT: The microbiota regulates chronic pain through the action of bacterial signals into two main locations: the peripheral nociceptors and the postsynaptic excitatory neurons in the spinal cord. The dysbiosis associated to Parkinson disease reveals increased representation of commensals that potentially exacerbate chronic pain and reduced levels of bacteria with beneficial effects on pain. This review encourages further research to better understand the signals involved in bacteria-bacteria and bacteria-host communication to get the clues for the development of probiotics with therapeutic potential.
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Affiliation(s)
- Zulmary Manjarres
- Laboratorio de Neuroinmunología, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile (Z.M., R.P.); Facultad de Ciencias Biológicas (Z.M., M.C.) and División de Anestesiología, Escuela de Medicina (M.C.), Pontificia Universidad Católica de Chile, Santiago, Chile; Millennium Nucleus for the Study of Pain, Santiago, Chile (Z.M., M.C.); and Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile (R.P.)
| | - Margarita Calvo
- Laboratorio de Neuroinmunología, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile (Z.M., R.P.); Facultad de Ciencias Biológicas (Z.M., M.C.) and División de Anestesiología, Escuela de Medicina (M.C.), Pontificia Universidad Católica de Chile, Santiago, Chile; Millennium Nucleus for the Study of Pain, Santiago, Chile (Z.M., M.C.); and Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile (R.P.)
| | - Rodrigo Pacheco
- Laboratorio de Neuroinmunología, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile (Z.M., R.P.); Facultad de Ciencias Biológicas (Z.M., M.C.) and División de Anestesiología, Escuela de Medicina (M.C.), Pontificia Universidad Católica de Chile, Santiago, Chile; Millennium Nucleus for the Study of Pain, Santiago, Chile (Z.M., M.C.); and Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile (R.P.)
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Konings B, Villatoro L, Van den Eynde J, Barahona G, Burns R, McKnight M, Hui K, Yenokyan G, Tack J, Pasricha PJ. Gastrointestinal syndromes preceding a diagnosis of Parkinson's disease: testing Braak's hypothesis using a nationwide database for comparison with Alzheimer's disease and cerebrovascular diseases. Gut 2023; 72:2103-2111. [PMID: 37620120 DOI: 10.1136/gutjnl-2023-329685] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 07/02/2023] [Indexed: 08/26/2023]
Abstract
OBJECTIVE Braak's hypothesis states that Parkinson's disease (PD) originates in the gastrointestinal (GI) tract, and similar associations have been established for Alzheimer's disease (AD) and cerebrovascular diseases (CVD). We aimed to determine the incidence of GI syndromes and interventions preceding PD compared with negative controls (NCs), AD and CVD. DESIGN We performed a combined case-control and cohort study using TriNetX, a US based nationwide medical record network. Firstly, we compared subjects with new onset idiopathic PD with matched NCs and patients with contemporary diagnoses of AD and CVD, to investigate preceding GI syndromes, appendectomy and vagotomy. Secondly, we compared cohorts with these exposures to matched NCs for the development of PD, AD and CVD within 5 years. RESULTS We identified 24 624 PD patients in the case-control analysis and matched 18 cohorts with each exposure to their NCs. Gastroparesis, dysphagia, irritable bowel syndrome (IBS) without diarrhoea and constipation showed specific associations with PD (vs NCs, AD and CVD) in both the case-control (odds ratios (ORs) vs NCs 4.64, 3.58, 3.53 and 3.32, respectively, all p<0.0001) and cohort analyses (relative risks (RRs) vs NCs 2.43, 2.27, 1.17 and 2.38, respectively, all p<0.05). While functional dyspepsia, IBS with diarrhoea, diarrhoea and faecal incontinence were not PD specific, IBS with constipation and intestinal pseudo-obstruction showed PD specificity in the case-control (OR 4.11) and cohort analysis (RR 1.84), respectively. Appendectomy decreased the risk of PD in the cohort analysis (RR 0.48). Neither inflammatory bowel disease nor vagotomy were associated with PD. CONCLUSION Dysphagia, gastroparesis, IBS without diarrhoea and constipation might specifically predict Parkinson's disease.
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Affiliation(s)
- Bo Konings
- Translational Research Centre for Gastrointestinal Disorders (TARGID), KU Leuven University Hospitals, Leuven, Belgium
| | - Luisa Villatoro
- Department of Medicine, Mayo Clinic Arizona, Scottsdale, Arizona, USA
| | - Jef Van den Eynde
- Department of Cardiology, KU Leuven University Hospitals, Leuven, Belgium
| | | | - Robert Burns
- Department of Gastroenterology, Johns Hopkins Medicine, Baltimore, Maryland, USA
| | - Megan McKnight
- Department of Gastroenterology, Johns Hopkins Medicine, Baltimore, Maryland, USA
| | - Ken Hui
- Department of Gastroenterology, Johns Hopkins Medicine, Baltimore, Maryland, USA
| | - Gayane Yenokyan
- Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Jan Tack
- Translational Research Centre for Gastrointestinal Disorders (TARGID), KU Leuven University Hospitals, Leuven, Belgium
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Woerman AL, Tamgüney G. Body-first Parkinson's disease and variant Creutzfeldt-Jakob disease - similar or different? Neurobiol Dis 2022; 164:105625. [PMID: 35026401 DOI: 10.1016/j.nbd.2022.105625] [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: 11/01/2021] [Revised: 01/03/2022] [Accepted: 01/07/2022] [Indexed: 10/19/2022] Open
Abstract
In several neurodegenerative disorders, proteins that typically exhibit an α-helical structure misfold into an amyloid conformation rich in β-sheet content. Through a self-templating mechanism, these amyloids are able to induce additional protein misfolding, facilitating their propagation throughout the central nervous system. This disease mechanism was originally identified for the prion protein (PrP), which misfolds into PrPSc in a number of disorders, including variant Creutzfeldt-Jakob disease (vCJD) and bovine spongiform encephalopathy (BSE). More recently, the prion mechanism of disease was expanded to include other proteins that rely on this self-templating mechanism to cause progressive degeneration, including α-synuclein misfolding in Parkinson's disease (PD). Several studies now suggest that PD patients can be subcategorized based on where in the body misfolded α-synuclein originates, either the brain or the gut, similar to patients developing sporadic CJD or vCJD. In this review, we discuss the human and animal model data indicating that α-synuclein and PrPSc misfolding originates in the gut in body-first PD and vCJD, and summarize the data identifying the role of the autonomic nervous system in the gut-brain axis of both diseases.
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Affiliation(s)
- Amanda L Woerman
- Institute for Applied Life Sciences and Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA.
| | - Gültekin Tamgüney
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany; Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany.
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7
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Dahbour SS, Subuh A, Haddad R, Al-Samardali T, Dahbour A. The role of appendectomy in the development of Parkinson’s disease: a retrospective study in a teaching hospital in Jordan. THE EGYPTIAN JOURNAL OF NEUROLOGY, PSYCHIATRY AND NEUROSURGERY 2021. [DOI: 10.1186/s41983-021-00352-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Parkinson’s disease is a degenerative brain disease related to the accumulation of an abnormally aggregated alpha-synuclein protein. A hypothesis was presumed that this protein will be transported retrogradely from the gastrointestinal tract ultimately leading to the disease. Various epidemiologic studies have shown conflicting results. This study reports the prevalence of appendectomy in Jordanian parkinsonian patients and compares it to controls seen at one major teaching hospital in Jordan. This is a retrospective study of 266 patients compared to a control group of 500 patients randomly selected from the hospital. The prevalence of appendectomy in the 2 groups was studied.
Results
The rate of appendectomy in patients and controls was 26/266 (9.8%) and 27/500 (5.4%), respectively (relative risk 1.30, odds ratio 1.81, χ2, p = 0.026). Appendectomy in the patients was independent of gender (χ2, p = 0.297). Also, there was no difference in patients with and without appendectomy regarding their age, age at diagnosis of PD, and duration of use of levodopa (p = 0.827, 0.960, and 0.688, respectively, Student t test). The mean duration from appendectomy to the diagnosis of the disease varied widely 23 ± 18.7 years, range −12–59 years.
Conclusions
Appendectomy occurred significantly more frequent in patients with Parkinson’s disease than in control. There was no difference regarding the age of onset of disease in the patients with and without appendectomy. Though the appendix in this study seems to have a protective role against the development of the disease, the relationship is quite complex requiring prospective in-depth evaluation.
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Song MY, Ullah S, Yang HY, Ahmed MR, Saleh AA, Liu BR. Long-term effects of appendectomy in humans: is it the optimal management of appendicitis? Expert Rev Gastroenterol Hepatol 2021; 15:657-664. [PMID: 33350352 DOI: 10.1080/17474124.2021.1868298] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Appendectomy remains the gold standard for treating uncomplicated and complicated appendicitis. However, the vermiform appendix may play a significant role in the immune system (secondary immune function) and maintain a reservoir of the normal microbiome for the human body. The aim of this study was to summarize the long-term effects after appendectomy and discuss whether appendectomy is suitable for all appendicitis patients. AREAS COVERED A comprehensive and unbiased literature search was performed in PubMed. The terms 'appendix,' 'appendicitis,' 'appendectomy,' and 'endoscopic retrograde appendicitis therapy' were searched in the title and/or abstract. This review summarizes the long-term effects of appendectomy on some diseases in humans and describes three methods including appendectomy, medical treatment, and an 'organ-sparing' technique, named endoscopic retrograde appendicitis therapy (ERAT) to treat appendicitis. EXPERT OPINION Appendectomy remains the first-line therapy for appendicitis. The patient's problem is appendix, not appendicitis. If we treat appendicitis, the problem should be resolved. During COVID-19, an initial antibiotic treatment of mild appendicitis represents a promising strategy. For patients who are worried about the long-term adverse effect after appendectomy and have a strong desire to preserve the appendix and are aware of the risk of appendicitis recurrence, medical treatment, or ERAT could be proposed.
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Affiliation(s)
- Ming-Yang Song
- Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,The Academy of Medical Science, Zhengzhou University, Zhengzhou, China
| | - Saif Ullah
- Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Hui-Yu Yang
- Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Md Robin Ahmed
- Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | | | - Bing-Rong Liu
- Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Chen Y, Wu W, Zhao S, Lv X, Hu J, Han C, Wang G, Wang S, Bo P, Zhang J, Gui W, Tang Q, Liu Q, Zhu S, Yu F. Increased Accumulation of α-Synuclein in Inflamed Appendices of Parkinson's Disease Patients. Mov Disord 2021; 36:1911-1918. [PMID: 33876851 DOI: 10.1002/mds.28553] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 01/12/2021] [Accepted: 01/18/2021] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The accumulation of α-synuclein (α-Syn) aggregates that leads to the onset of Parkinson's disease (PD) has been postulated to begin in the gastrointestinal tract. The normal human appendix contains pathogenic forms of α-Syn, and appendectomy has been reported to affect the incidence of PD. OBJECTIVE This study investigated appendix abnormality in patients with PD. METHODS We assessed appendix morphology in 100 patients with PD and 50 control subjects by multislice spiral computed tomography. We analyzed the clinical characteristics of patients with PD with diseased appendices, which was confirmed in seven patients by histopathological analysis. RESULTS Chronic appendicitis-like lesions were detected in 53% of patients with PD, but these were not associated with the duration of motor symptoms. Appendicitis-like lesions, impaired olfaction, and rapid eye movement sleep behavior disorder were risk factors for PD. The following clinical symptoms could be used to identify patients with PD with appendicitis-like lesions: first motor symptoms were bradykinesia/rigidity, onset of motor symptoms in the central axis or left limb, prodromal constipation, high ratio of Unified Parkinson's Disease Rating Scale Part III score to symptom duration, low Montreal Cognitive Assessment score, and high Epworth Sleepiness Scale score. The seven patients with PD who were diagnosed with chronic appendicitis underwent appendectomy, and histopathological analysis revealed structural changes associated with chronic appendicitis and α-Syn aggregation. CONCLUSIONS These results indicate an association between chronic appendicitis-like lesions and PD, and suggest that α-Syn accumulation in the diseased appendix occurs in PD. © 2021 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Yuhua Chen
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Wei Wu
- Department of Surgery, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Shuli Zhao
- Department of Radiology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Xinyi Lv
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Ji Hu
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.,Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Chao Han
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.,Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Guoping Wang
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Shicun Wang
- Department of Radiology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Pan Bo
- Department of Radiology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Juan Zhang
- The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Wei Gui
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Qiqiang Tang
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Qiang Liu
- The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Shu Zhu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Feng Yu
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
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Babakhanov AT, Dzhumabekov AT, Zhao AV, Kuandykov YK, Tanabayeva SB, Fakhradiyev IR, Nazarenko Y, Saliev TM. Impact of Appendectomy on Gut Microbiota. Surg Infect (Larchmt) 2021; 22:651-661. [PMID: 33523761 DOI: 10.1089/sur.2020.422] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background: Considered vestigial from the classic point of view, the vermiform appendix has long been the subject of intensive studies. The recent understanding of appendix function in the context of unique architecture and bacterial complexity and density allows considering it as a safehouse for intestinal biodiversity. Methods: This review analyzes and assesses the current state of scientific knowledge regarding the role of the vermiform appendix in normal gut microbiota maintenance as a crucial factor of host homeostasis. It also highlights the difference in microbial composition between the large bowel and the appendix, as well as the association between the surgical excision, appendectomy, and dysbiosis-induced diseases. In addition, the review discusses the results of epidemiologic studies on appendectomy as a risk factor for the initiation of gastrointestinal carcinogenesis. It also highlights the association between appendectomy and a series of chronic inflammatory and neurologic disorders, including inflammatory bowel disease.
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Affiliation(s)
| | | | - Alexey V Zhao
- Institute of Surgery named after A.V. Vishnevsky, Moscow, Russia
| | - Yerlan K Kuandykov
- Khoja Akhmet Yassawi International Kazakh-Turkish University, Shymkent Medical Institute Postgraduate Studies Faculty, Shymkent, Kazakhstan
| | | | | | - Yana Nazarenko
- S.D. Asfendiyarov Kazakh National Medical University, Almaty, Kazakhstan
| | - Timur M Saliev
- S.D. Asfendiyarov Kazakh National Medical University, Almaty, Kazakhstan
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Ishizuka M, Shibuya N, Takagi K, Hachiya H, Tago K, Suda K, Aoki T, Kubota K. Appendectomy Does Not Increase the Risk of Future Emergence of Parkinson's Disease: A Meta-analysis. Am Surg 2021; 87:1802-1808. [PMID: 33522253 DOI: 10.1177/0003134821989034] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To explore the impact of appendectomy history on emergence of Parkinson's disease (PD). BACKGROUND Although there are several studies to investigate the relationship between appendectomy history and emergence of PD, the results are still controversial. METHODS We performed a comprehensive electronic search of the literature (the Cochrane Library, PubMed, and the Web of Science) up to April 2020 to identify studies that had employed databases allowing comparison of emergence of PD between patients with and those without appendectomy history. To integrate the impact of appendectomy history on emergence of PD, a meta-analysis was performed using random-effects models to calculate the risk ratio (RR) and 95% confidence interval (CI) for the selected studies, and heterogeneity was analyzed using I2 statistics. RESULTS Four studies involving a total of 6 080 710 patients were included in this meta-analysis. Among 1 470 613 patients with appendectomy history, 1845 (.13%) had emergences of PD during the observation period, whereas among 4 610 097 patients without appendectomy history, 6743 (.15%) had emergences of PD during the observation period. These results revealed that patients with appendectomy history and without appendectomy had almost the same emergence of PD (RR, 1.02; 95% CI, .87-1.20; P = .83; I2 = 87%). CONCLUSION This meta-analysis has demonstrated that there was no significant difference in emergence of PD between patients with and those without appendectomy history.
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Affiliation(s)
- Mitsuru Ishizuka
- Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi, Japan
| | - Norisuke Shibuya
- Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi, Japan
| | - Kazutoshi Takagi
- Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi, Japan
| | - Hiroyuki Hachiya
- Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi, Japan
| | - Kazuma Tago
- Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi, Japan
| | - Kotaro Suda
- Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi, Japan
| | - Taku Aoki
- Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi, Japan
| | - Keiichi Kubota
- Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi, Japan
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12
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Lack of association between appendectomy and Parkinson's disease: a systematic review and meta-analysis. Aging Clin Exp Res 2020; 32:2201-2209. [PMID: 31538320 DOI: 10.1007/s40520-019-01354-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/10/2019] [Indexed: 02/08/2023]
Abstract
BACKGROUND Accumulation of aggregated α-synuclein from the enteric nervous system is believed to be involved in the pathogenesis of Parkinson's disease (PD). The appendix contains abundant α-synuclein and lacks a blood-tissue barrier, suggesting that appendectomy might reduce α-synuclein aggregation, and therefore the risk of PD. Studies on this intriguing possibility have not come to consistent conclusions. METHODS PubMed, Embase (via Ovid), and the Cochrane Controlled Register of Trials were searched for studies published through February 20, 2019 on the potential relationship between appendectomy and PD. Two reviewers independently screened literature, extracted data and evaluated the quality of included studies. Data were summarized as pooled effect sizes (RRs or SMDs) with 95% confidence intervals (CIs), which were calculated using the inverse variance method and a random-effects model. Heterogeneity was assessed using the I2 statistic and explored in subgroup analyses. RESULTS Of the 408 references screened, six studies involving 3,554,540 people were included eventually. Appendectomy did not significantly affect PD risk (RR 1.02, 95% CI 0.87-1.20, I2 = 83.1%, P = 0.789) or delay its onset (SMD 0.21, 95% CI - 0.03 to 0.44, I2 = 43.4%, P = 0.083). CONCLUSION The available evidence suggests no protective effect of appendectomy against PD. Future studies should seek to clarify the role of inflammation, α-synuclein pathology and the gut-brain axis in PD pathogenesis.
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13
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Abstract
The gut microbiome is increasingly implicated in modifying susceptibility to and progression of neurodegenerative diseases (NDs). In this review, we discuss roles for the microbiome in aging and in NDs. In particular, we summarize findings from human studies on microbiome alterations in Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, and Huntington's disease. We assess animal studies of genetic and environmental models for NDs that investigate how manipulations of the microbiome causally impact the development of behavioral and neuropathological endophenotypes of disease. We additionally evaluate the likely immunological, neuronal, and metabolic mechanisms for how the gut microbiota may modulate risk for NDs. Finally, we speculate on cross-cutting features for microbial influences across multiple NDs and consider the potential for microbiome-targeted interventions for NDs.
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Affiliation(s)
- P Fang
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - S A Kazmi
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - K G Jameson
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - E Y Hsiao
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
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14
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Yan YQ, Fang Y, Zheng R, Pu JL, Zhang BR. NLRP3 Inflammasomes in Parkinson's disease and their Regulation by Parkin. Neuroscience 2020; 446:323-334. [PMID: 32795556 DOI: 10.1016/j.neuroscience.2020.08.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 08/01/2020] [Accepted: 08/03/2020] [Indexed: 12/17/2022]
Abstract
Chronic inflammation might correlate with the formation of α-synuclein oligomers, subsequently leading to dopaminergic (DA) neuronal death in Parkinson's disease (PD). As major components of chronic inflammation, NOD-like receptor protein 3 (NLRP3) inflammasomes play a crucial role in PD via caspase 1 activation, primarily induced by mitochondrial damage. NLRP3 binds to apoptosis-associated speck-like protein containing a CARD (PYCARD/ASC), and forms inflammasomes in the brain. Inflammasomes act as a platform for caspase 1 to induce interleukin 1 Beta (IL1β) maturation, leading to neuronal pyroptosis. Furthermore, alpha-synuclein, whose abnormal aggregation is the main pathogenesis of PD, also activates NLRP3 inflammasomes. Mutations to PRKN (encoding Parkin) are the most common cause of autosomal recessive familial and sporadic early-onset PD. Evidence has confirmed a relationship between Parkin and NLRP3 inflammasomes. In this review, we summarize the current understanding of NLRP3 inflammasomes and their role in PD progression, and discuss their regulation by Parkin.
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Affiliation(s)
- Yi-Qun Yan
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, China
| | - Yi Fang
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, China
| | - Ran Zheng
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, China
| | - Jia-Li Pu
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, China.
| | - Bao-Rong Zhang
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, China.
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15
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Liu B, Fang F, Ye W, Wirdefeldt K. Appendectomy, Tonsillectomy and Parkinson's Disease Risk: A Swedish Register-Based Study. Front Neurol 2020; 11:510. [PMID: 32595591 PMCID: PMC7292857 DOI: 10.3389/fneur.2020.00510] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 05/08/2020] [Indexed: 11/13/2022] Open
Abstract
Introduction: The gut-brain hypothesis proposes that Parkinson's disease (PD) pathology may start in the gut and later spread to the brain in a prion-like manner. As PD pathology is redundant in the appendix and tonsils, which are important gut-associated lymphoid tissues, we examined whether appendectomy and tonsillectomy were associated with later PD risk. Methods: The nested case-control study included 78,650 PD patients born in 1900-1980 and with a diagnosis of PD between 1964 and 2010. For each PD patient, we randomly selected 40 non-PD controls individually matched for sex and year of birth at the date of PD diagnosis. Appendectomy and tonsillectomy before PD diagnosis were ascertained from the Swedish Patient Register from 1964 onward. We calculated odds ratios (OR) with 95% confidence intervals (CI) using conditional logistic regression adjusting for country of birth, highest achieved education, COPD, comorbidity index, and number of hospital visits. Results: Overall, we found 16% lower risk of PD linked to previous appendectomy (OR = 0.84, 95% CI: 0.80-0.88) and 8% lower risk of PD linked to previous tonsillectomy, although not statistically significant (OR = 0.92, 95% CI: 0.81-1.04). A 7 and 15% lower risk of PD was also noted ≥20 years after appendectomy and tonsillectomy, respectively. Similar associations were observed for men and women but were stronger for PD diagnosed after age 60. Conclusion: Appendectomy and potentially also tonsillectomy were associated with a lower risk PD. A potential mechanism may involve surgical removal of alpha-synuclein redundancy in the appendix and tonsils.
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Affiliation(s)
- Bojing Liu
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Fang Fang
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Weimin Ye
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Karin Wirdefeldt
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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16
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Killinger BA, Madaj Z, Sikora JW, Rey N, Haas AJ, Vepa Y, Lindqvist D, Chen H, Thomas PM, Brundin P, Brundin L, Labrie V. The vermiform appendix impacts the risk of developing Parkinson's disease. Sci Transl Med 2019; 10:10/465/eaar5280. [PMID: 30381408 DOI: 10.1126/scitranslmed.aar5280] [Citation(s) in RCA: 186] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/14/2018] [Accepted: 06/08/2018] [Indexed: 12/12/2022]
Abstract
The pathogenesis of Parkinson's disease (PD) involves the accumulation of aggregated α-synuclein, which has been suggested to begin in the gastrointestinal tract. Here, we determined the capacity of the appendix to modify PD risk and influence pathogenesis. In two independent epidemiological datasets, involving more than 1.6 million individuals and over 91 million person-years, we observed that removal of the appendix decades before PD onset was associated with a lower risk for PD, particularly for individuals living in rural areas, and delayed the age of PD onset. We also found that the healthy human appendix contained intraneuronal α-synuclein aggregates and an abundance of PD pathology-associated α-synuclein truncation products that are known to accumulate in Lewy bodies, the pathological hallmark of PD. Lysates of human appendix tissue induced the rapid cleavage and oligomerization of full-length recombinant α-synuclein. Together, we propose that the normal human appendix contains pathogenic forms of α-synuclein that affect the risk of developing PD.
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Affiliation(s)
- Bryan A Killinger
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Zachary Madaj
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Jacek W Sikora
- Proteomics Center of Excellence, Northwestern University, Evanston, IL, USA
| | - Nolwen Rey
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA.,Paris-Saclay Institute of Neuroscience, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France
| | - Alec J Haas
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Yamini Vepa
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Daniel Lindqvist
- Department of Clinical Sciences, Psychiatry, Faculty of Medicine, Lund University, Lund, Sweden.,Psychiatric Clinic, Lund, Division of Psychiatry, Lund, Sweden
| | - Honglei Chen
- Department of Epidemiology and Biostatistics, College of Human Medicine, Michigan State University, East Lansing, MI, USA
| | - Paul M Thomas
- Proteomics Center of Excellence, Northwestern University, Evanston, IL, USA
| | - Patrik Brundin
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Lena Brundin
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Viviane Labrie
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA. .,Centre for Addiction and Mental Health, Toronto, ON, Canada
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Parker A, Fonseca S, Carding SR. Gut microbes and metabolites as modulators of blood-brain barrier integrity and brain health. Gut Microbes 2019; 11:135-157. [PMID: 31368397 PMCID: PMC7053956 DOI: 10.1080/19490976.2019.1638722] [Citation(s) in RCA: 329] [Impact Index Per Article: 65.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/22/2019] [Accepted: 06/26/2019] [Indexed: 02/03/2023] Open
Abstract
The human gastrointestinal (gut) microbiota comprises diverse and dynamic populations of bacteria, archaea, viruses, fungi, and protozoa, coexisting in a mutualistic relationship with the host. When intestinal homeostasis is perturbed, the function of the gastrointestinal tract and other organ systems, including the brain, can be compromised. The gut microbiota is proposed to contribute to blood-brain barrier disruption and the pathogenesis of neurodegenerative diseases. While progress is being made, a better understanding of interactions between gut microbes and host cells, and the impact these have on signaling from gut to brain is now required. In this review, we summarise current evidence of the impact gut microbes and their metabolites have on blood-brain barrier integrity and brain function, and the communication networks between the gastrointestinal tract and brain, which they may modulate. We also discuss the potential of microbiota modulation strategies as therapeutic tools for promoting and restoring brain health.
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Affiliation(s)
- Aimée Parker
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - Sonia Fonseca
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - Simon R. Carding
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
- Norwich Medical School, University of East Anglia, Norwich, UK
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18
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Ma J, Gao J, Wang J, Xie A. Prion-Like Mechanisms in Parkinson's Disease. Front Neurosci 2019; 13:552. [PMID: 31275093 PMCID: PMC6591488 DOI: 10.3389/fnins.2019.00552] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 05/13/2019] [Indexed: 12/11/2022] Open
Abstract
Formation and aggregation of misfolded proteins in the central nervous system (CNS) is a key hallmark of several age-related neurodegenerative diseases, including Parkinson’s disease (PD), Alzheimer’s disease (AD), and amyotrophic lateral sclerosis (ALS). These diseases share key biophysical and biochemical characteristics with prion diseases. It is believed that PD is characterized by abnormal protein aggregation, mainly that of α-synuclein (α-syn). Of particular importance, there is growing evidence indicating that abnormal α-syn can spread to neighboring brain regions and cause aggregation of endogenous α-syn in these regions as seeds, in a “prion-like” manner. Abundant studies in vitro and in vivo have shown that α-syn goes through a templated conformational change, propagates from the original region to neighboring regions, and eventually cause neuron degeneration in the substantia nigra and striatum. The objective of this review is to summarize the mechanisms involved in the aggregation of abnormal intracellular α-syn and its subsequent cell-to-cell transmission. According to these findings, we look forward to effective therapeutic perspectives that can block the progression of neurodegenerative diseases.
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Affiliation(s)
- Jiangnan Ma
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jing Gao
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jing Wang
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Anmu Xie
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, China
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19
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Is Parkinson's disease a chronic low-grade inflammatory bowel disease? J Neurol 2019; 267:2207-2213. [PMID: 30989372 DOI: 10.1007/s00415-019-09321-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 04/09/2019] [Accepted: 04/10/2019] [Indexed: 12/17/2022]
Abstract
While the pathogenesis of Parkinson's disease is not fully understood, there is increasing evidence that inflammatory responses in the brain are implicated in both disease initiation and progression. The inflammatory process in Parkinson's disease is, however, not limited to the brain but also involves the gastrointestinal tract. High amounts of cytokines and inflammatory markers are found in the colon of Parkinson's disease patients and there is now strong epidemiological and genetical evidence linking Parkinson's disease to inflammatory bowel diseases. Recent findings obtained in both experimental inflammatory bowel diseases and Parkinson's disease further support a bidirectional link between gastrointestinal inflammation and brain neurodegeneration. Altogether, these observations suggest a role for gastrointestinal inflammation in the initiation and progression of Parkinson's disease.
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20
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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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21
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Killinger B, Labrie V. The Appendix in Parkinson's Disease: From Vestigial Remnant to Vital Organ? JOURNAL OF PARKINSON'S DISEASE 2019; 9:S345-S358. [PMID: 31609697 PMCID: PMC6839473 DOI: 10.3233/jpd-191703] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 09/13/2019] [Indexed: 02/07/2023]
Abstract
Parkinson's disease (PD) has long been considered a brain disease, but studies now point to the gastrointestinal (GI) tract as a potential starting point for PD. In particular, the human vermiform appendix has been implicated in PD. The appendix is a tissue rich in immune cells, serving as part of the gut-associated lymphoid tissue and as a storehouse for the gut microbiome. The functions of the appendix converge with recent evidence demonstrating that gut inflammation and shifts in the microbiome are linked to PD. Some epidemiological studies have linked removal of the appendix to lowered PD risk, though there is controversy among these associations. What is apparent is that there is an abundance of aggregated forms of α-synuclein in the appendix relevant to PD pathology. α-Synuclein pathology is thought to propagate from gut to brain via the vagus nerve, which innervates GI tract locations, including the appendix. Remarkably, α-synuclein aggregates in the appendix occur not only in PD patients, but are also present in healthy individuals. This has led to the proposal that in the appendix α-synuclein aggregates are not unique to PD. Moreover, the molecular events leading to PD and the mechanisms by which α-synuclein aggregates transfers from gut to brain may be identifiable in the human appendix. The influence of the appendix on GI inflammation, autoimmunity, microbiome storage, and the lymphatic system may be yet unexplored mechanisms by which the appendix contributes to PD. Overall, the appendix represents a promising tissue site to advance our understanding of PD pathobiology.
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Affiliation(s)
- Bryan Killinger
- Department of Neurological Sciences, Rush Medical College, Chicago, IL, USA
| | - Viviane Labrie
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
- Division of Psychiatry and Behavioral Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
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22
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Girard-Madoux MJ, Gomez de Agüero M, Ganal-Vonarburg SC, Mooser C, Belz GT, Macpherson AJ, Vivier E. The immunological functions of the Appendix: An example of redundancy? Semin Immunol 2018; 36:31-44. [DOI: 10.1016/j.smim.2018.02.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 02/16/2018] [Indexed: 12/12/2022]
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