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Naik B, Sasikumar J, Das SP. From Skin and Gut to the Brain: The Infectious Journey of the Human Commensal Fungus Malassezia and Its Neurological Consequences. Mol Neurobiol 2024:10.1007/s12035-024-04270-w. [PMID: 38871941 DOI: 10.1007/s12035-024-04270-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 05/27/2024] [Indexed: 06/15/2024]
Abstract
The human mycobiome encompasses diverse communities of fungal organisms residing within the body and has emerged as a critical player in shaping health and disease. While extensive research has focused on the skin and gut mycobiome, recent investigations have pointed toward the potential role of fungal organisms in neurological disorders. Among those fungal organisms, the presence of the commensal fungus Malassezia in the brain has created curiosity because of its commensal nature and primary association with the human skin and gut. This budding yeast is responsible for several diseases, such as Seborrheic dermatitis, Atopic dermatitis, Pityriasis versicolor, Malassezia folliculitis, dandruff, and others. However recent findings surprisingly show the presence of Malassezia DNA in the brain and have been linked to diseases like Alzheimer's disease, Parkinson's disease, Multiple sclerosis, and Amyotrophic lateral sclerosis. The exact role of Malassezia in these disorders is unknown, but its ability to infect human cells, travel through the bloodstream, cross the blood-brain barrier, and reside along with the lipid-rich neuronal cells are potential mechanisms responsible for pathogenesis. This also includes the induction of pro-inflammatory cytokines, disruption of the blood-brain barrier, gut-microbe interaction, and accumulation of metabolic changes in the brain environment. In this review, we discuss these key findings from studies linking Malassezia to neurological disorders, emphasizing the complex and multifaceted nature of these cases. Furthermore, we discuss potential mechanisms through which Malassezia might contribute to the development of neurological conditions. Future investigations will open up new avenues for our understanding of the fungal gut-brain axis and how it influences human behavior. Collaborative research efforts among microbiologists, neuroscientists, immunologists, and clinicians hold promise for unraveling the enigmatic connections between human commensal Malassezia and neurological disorders.
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Affiliation(s)
- Bharati Naik
- Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, 575018, India
| | - Jayaprakash Sasikumar
- Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, 575018, India
| | - Shankar Prasad Das
- Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, 575018, India.
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2
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Kettunen P, Koistinaho J, Rolova T. Contribution of CNS and extra-CNS infections to neurodegeneration: a narrative review. J Neuroinflammation 2024; 21:152. [PMID: 38845026 PMCID: PMC11157808 DOI: 10.1186/s12974-024-03139-y] [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: 03/17/2024] [Accepted: 05/23/2024] [Indexed: 06/09/2024] Open
Abstract
Central nervous system infections have been suggested as a possible cause for neurodegenerative diseases, particularly sporadic cases. They trigger neuroinflammation which is considered integrally involved in neurodegenerative processes. In this review, we will look at data linking a variety of viral, bacterial, fungal, and protozoan infections to Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis and unspecified dementia. This narrative review aims to bring together a broad range of data currently supporting the involvement of central nervous system infections in the development of neurodegenerative diseases. The idea that no single pathogen or pathogen group is responsible for neurodegenerative diseases will be discussed. Instead, we suggest that a wide range of susceptibility factors may make individuals differentially vulnerable to different infectious pathogens and subsequent pathologies.
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Affiliation(s)
- Pinja Kettunen
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Jari Koistinaho
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.
| | - Taisia Rolova
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
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3
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Aliashrafi M, Nasehi M, Zarrindast MR, Joghataei MT, Zali H, Siadat SD. Intracerebroventricular Cutibacterium acnes Generates Manifestations of Alzheimer's Disease-like Pathology in the Rat Hippocampus. Neuroscience 2024; 540:103-116. [PMID: 38266907 DOI: 10.1016/j.neuroscience.2024.01.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 01/13/2024] [Accepted: 01/16/2024] [Indexed: 01/26/2024]
Abstract
The infection hypothesis is a new causative explanation for Alzheimer's disease (AD). In recent decades, various species of bacterial pathogens have been distinguished in the autopsy of Alzheimer's patients; however, the mechanism of bacterial contribution to AD pathology is still unknown. To explore the hypothesis, Cutibacterium acnes (C. acnes) was selected, and effects of its intracerebroventricular (ICV) inoculation in rats was evaluated. The results revealed that C. acnes causes memory impairment, which might be a consequence of upregulated Amyloid β (Aβ) deposits in the hippocampus; Aβ aggregates are co-localized with C. acnes colonies. The key point of our hypothesis is that the activation of the innate immune system by C. acnes through the TLR2/NF-κB/NLRP3 signaling pathway, eventually leads to increased neuroinflammation, which might be resulted from microgliosis and astrogliosis. Neuroinflammation increases oxidative stress and cell apoptosis. Overall, the obtained results of this study support our hypothesis that brain exposure to C. acnes prompted neuroinflammation with similar AD-like pathology.
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Affiliation(s)
- Morteza Aliashrafi
- Department of Cognitive Neuroscience, Institute for Cognitive Science Studies, Tehran, Iran; Shahid Beheshti University, Tehran, Iran
| | - Mohammad Nasehi
- Cognitive and Neuroscience Research Center, Amir-Almomenin Hospital, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
| | - Mohammad-Reza Zarrindast
- Department of Cognitive Neuroscience, Institute for Cognitive Science Studies, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad-Taghi Joghataei
- Cellular and Molecular Research Center, Department of Neuroscience, Iran University of Medical Science, Tehran, Iran
| | - Hakimeh Zali
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Seyed Davar Siadat
- Department of Mycobacteriology and Pulmonary Research, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
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4
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Ekwudo MN, Gubert C, Hannan AJ. The microbiota-gut-brain axis in Huntington's disease: pathogenic mechanisms and therapeutic targets. FEBS J 2024. [PMID: 38426291 DOI: 10.1111/febs.17102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/08/2024] [Accepted: 02/14/2024] [Indexed: 03/02/2024]
Abstract
Huntington's disease (HD) is a currently incurable neurogenerative disorder and is typically characterized by progressive movement disorder (including chorea), cognitive deficits (culminating in dementia), psychiatric abnormalities (the most common of which is depression), and peripheral symptoms (including gastrointestinal dysfunction). There are currently no approved disease-modifying therapies available for HD, with death usually occurring approximately 10-25 years after onset, but some therapies hold promising potential. HD subjects are often burdened by chronic diarrhea, constipation, esophageal and gastric inflammation, and a susceptibility to diabetes. Our understanding of the microbiota-gut-brain axis in HD is in its infancy and growing evidence from preclinical and clinical studies suggests a role of gut microbial population imbalance (gut dysbiosis) in HD pathophysiology. The gut and the brain can communicate through the enteric nervous system, immune system, vagus nerve, and microbiota-derived-metabolites including short-chain fatty acids, bile acids, and branched-chain amino acids. This review summarizes supporting evidence demonstrating the alterations in bacterial and fungal composition that may be associated with HD. We focus on mechanisms through which gut dysbiosis may compromise brain and gut health, thus triggering neuroinflammatory responses, and further highlight outcomes of attempts to modulate the gut microbiota as promising therapeutic strategies for HD. Ultimately, we discuss the dearth of data and the need for more longitudinal and translational studies in this nascent field. We suggest future directions to improve our understanding of the association between gut microbes and the pathogenesis of HD, and other 'brain and body disorders'.
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Affiliation(s)
- Millicent N Ekwudo
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Australia
| | - Carolina Gubert
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Australia
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Australia
- Department of Anatomy and Physiology, University of Melbourne, Parkville, Australia
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Arabi TZ, Alabdulqader AA, Sabbah BN, Ouban A. Brain-inhabiting bacteria and neurodegenerative diseases: the "brain microbiome" theory. Front Aging Neurosci 2023; 15:1240945. [PMID: 37927338 PMCID: PMC10620799 DOI: 10.3389/fnagi.2023.1240945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/29/2023] [Indexed: 11/07/2023] Open
Abstract
Controversies surrounding the validity of the toxic proteinopathy theory of Alzheimer's disease have led the scientific community to seek alternative theories in the pathogenesis of neurodegenerative disorders (ND). Recent studies have provided evidence of a microbiome in the central nervous system. Some have hypothesized that brain-inhabiting organisms induce chronic neuroinflammation, leading to the development of a spectrum of NDs. Bacteria such as Chlamydia pneumoniae, Helicobacter pylori, and Cutibacterium acnes have been found to inhabit the brains of ND patients. Furthermore, several fungi, including Candida and Malassezia species, have been identified in the central nervous system of these patients. However, there remains several limitations to the brain microbiome hypothesis. Varying results across the literature, concerns regarding sample contamination, and the presence of exogenous deoxyribonucleic acids have led to doubts about the hypothesis. These results provide valuable insight into the pathogenesis of NDs. Herein, we provide a review of the evidence for and against the brain microbiome theory and describe the difficulties facing the hypothesis. Additionally, we define possible mechanisms of bacterial invasion of the brain and organism-related neurodegeneration in NDs and the potential therapeutic premises of this theory.
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Affiliation(s)
| | | | | | - Abderrahman Ouban
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
- Department of Pathology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Moné Y, Earl JP, Król JE, Ahmed A, Sen B, Ehrlich GD, Lapides JR. Evidence supportive of a bacterial component in the etiology for Alzheimer's disease and for a temporal-spatial development of a pathogenic microbiome in the brain. Front Cell Infect Microbiol 2023; 13:1123228. [PMID: 37780846 PMCID: PMC10534976 DOI: 10.3389/fcimb.2023.1123228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 07/05/2023] [Indexed: 10/03/2023] Open
Abstract
Background Over the last few decades, a growing body of evidence has suggested a role for various infectious agents in Alzheimer's disease (AD) pathogenesis. Despite diverse pathogens (virus, bacteria, fungi) being detected in AD subjects' brains, research has focused on individual pathogens and only a few studies investigated the hypothesis of a bacterial brain microbiome. We profiled the bacterial communities present in non-demented controls and AD subjects' brains. Results We obtained postmortem samples from the brains of 32 individual subjects, comprising 16 AD and 16 control age-matched subjects with a total of 130 samples from the frontal and temporal lobes and the entorhinal cortex. We used full-length 16S rRNA gene amplification with Pacific Biosciences sequencing technology to identify bacteria. We detected bacteria in the brains of both cohorts with the principal bacteria comprising Cutibacterium acnes (formerly Propionibacterium acnes) and two species each of Acinetobacter and Comamonas genera. We used a hierarchical Bayesian method to detect differences in relative abundance among AD and control groups. Because of large abundance variances, we also employed a new analysis approach based on the Latent Dirichlet Allocation algorithm, used in computational linguistics. This allowed us to identify five sample classes, each revealing a different microbiota. Assuming that samples represented infections that began at different times, we ordered these classes in time, finding that the last class exclusively explained the existence or non-existence of AD. Conclusions The AD-related pathogenicity of the brain microbiome seems to be based on a complex polymicrobial dynamic. The time ordering revealed a rise and fall of the abundance of C. acnes with pathogenicity occurring for an off-peak abundance level in association with at least one other bacterium from a set of genera that included Methylobacterium, Bacillus, Caulobacter, Delftia, and Variovorax. C. acnes may also be involved with outcompeting the Comamonas species, which were strongly associated with non-demented brain microbiota, whose early destruction could be the first stage of disease. Our results are also consistent with a leaky blood-brain barrier or lymphatic network that allows bacteria, viruses, fungi, or other pathogens to enter the brain.
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Affiliation(s)
- Yves Moné
- Department of Microbiology and Immunology, Centers for Genomic Sciences and Advanced Microbial Processing, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Joshua P Earl
- Department of Microbiology and Immunology, Centers for Genomic Sciences and Advanced Microbial Processing, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Jarosław E Król
- Department of Microbiology and Immunology, Centers for Genomic Sciences and Advanced Microbial Processing, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Azad Ahmed
- Department of Microbiology and Immunology, Centers for Genomic Sciences and Advanced Microbial Processing, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Bhaswati Sen
- Department of Microbiology and Immunology, Centers for Genomic Sciences and Advanced Microbial Processing, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Garth D Ehrlich
- Department of Microbiology and Immunology, Centers for Genomic Sciences and Advanced Microbial Processing, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Jeffrey R Lapides
- Department of Microbiology and Immunology, Centers for Genomic Sciences and Advanced Microbial Processing, Drexel University College of Medicine, Philadelphia, PA, United States
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Spencer PS, Palmer VS, Kisby GE, Lagrange E, Horowitz BZ, Valdes Angues R, Reis J, Vernoux JP, Raoul C, Camu W. Early-onset, conjugal, twin-discordant, and clusters of sporadic ALS: Pathway to discovery of etiology via lifetime exposome research. Front Neurosci 2023; 17:1005096. [PMID: 36860617 PMCID: PMC9969898 DOI: 10.3389/fnins.2023.1005096] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 01/09/2023] [Indexed: 02/17/2023] Open
Abstract
The identity and role of environmental factors in the etiology of sporadic amyotrophic lateral sclerosis (sALS) is poorly understood outside of three former high-incidence foci of Western Pacific ALS and a hotspot of sALS in the French Alps. In both instances, there is a strong association with exposure to DNA-damaging (genotoxic) chemicals years or decades prior to clinical onset of motor neuron disease. In light of this recent understanding, we discuss published geographic clusters of ALS, conjugal cases, single-affected twins, and young-onset cases in relation to their demographic, geographic and environmental associations but also whether, in theory, there was the possibility of exposure to genotoxic chemicals of natural or synthetic origin. Special opportunities to test for such exposures in sALS exist in southeast France, northwest Italy, Finland, the U.S. East North Central States, and in the U.S. Air Force and Space Force. Given the degree and timing of exposure to an environmental trigger of ALS may be related to the age at which the disease is expressed, research should focus on the lifetime exposome (from conception to clinical onset) of young sALS cases. Multidisciplinary research of this type may lead to the identification of ALS causation, mechanism, and primary prevention, as well as to early detection of impending ALS and pre-clinical treatment to slow development of this fatal neurological disease.
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Affiliation(s)
- Peter S. Spencer
- Department of Neurology, School of Medicine, Oregon Health and Science University, Portland, OR, United States,Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, OR, United States,*Correspondence: Peter S. Spencer,
| | - Valerie S. Palmer
- Department of Neurology, School of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Glen E. Kisby
- College of Osteopathic Medicine of the Pacific Northwest, Western University of Health Sciences, Lebanon, OR, United States
| | - Emmeline Lagrange
- Department of Neurology, Reference Center of Neuromuscular Disease and ALS Consultations, Grenoble University Hospital, Grenoble, France
| | - B. Zane Horowitz
- Department of Emergency Medicine, Oregon-Alaska Poison Center, Oregon Health and Science University, Portland, OR, United States
| | - Raquel Valdes Angues
- Department of Neurology, School of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Jacques Reis
- University of Strasbourg, Faculté de Médecine, Strasbourg, France
| | - Jean-Paul Vernoux
- Normandie Université, UNICAEN, Unité de Recherche Aliments Bioprocédés Toxicologie Environnements, Caen, France
| | - Cédric Raoul
- INM, University of Montpellier, INSERM, Montpellier, France
| | - William Camu
- ALS Reference Center, Montpellier University Hospital and University of Montpellier, INSERM, Montpellier, France
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Tran VTA, Lee LP, Cho H. Neuroinflammation in neurodegeneration via microbial infections. Front Immunol 2022; 13:907804. [PMID: 36052093 PMCID: PMC9425114 DOI: 10.3389/fimmu.2022.907804] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/01/2022] [Indexed: 11/13/2022] Open
Abstract
Recent epidemiological studies show a noticeable correlation between chronic microbial infections and neurological disorders. However, the underlying mechanisms are still not clear due to the biological complexity of multicellular and multiorgan interactions upon microbial infections. In this review, we show the infection leading to neurodegeneration mediated by multiorgan interconnections and neuroinflammation. Firstly, we highlight three inter-organ communications as possible routes from infection sites to the brain: nose-brain axis, lung-brain axis, and gut-brain axis. Next, we described the biological crosstalk between microglia and astrocytes upon pathogenic infection. Finally, our study indicates how neuroinflammation is a critical player in pathogen-mediated neurodegeneration. Taken together, we envision that antibiotics targeting neuro-pathogens could be a potential therapeutic strategy for neurodegeneration.
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Affiliation(s)
- Van Thi Ai Tran
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon, South Korea
| | - Luke P. Lee
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon, South Korea
- Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Harvard Institute of Medicine, Harvard University, Boston, MA, United States
- *Correspondence: Hansang Cho, ; Luke P. Lee,
| | - Hansang Cho
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon, South Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon, South Korea
- *Correspondence: Hansang Cho, ; Luke P. Lee,
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Weldick PJ, Wang A, Halbus AF, Paunov VN. Emerging nanotechnologies for targeting antimicrobial resistance. NANOSCALE 2022; 14:4018-4041. [PMID: 35234774 DOI: 10.1039/d1nr08157h] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Antimicrobial resistance is a leading cause of mortality worldwide. Without newly approved antibiotics and antifungals being brought to the market, resistance is being developed to the ones currently available to clinicians. The reason is the applied evolutionary pressure to bacterial and fungal species due to the wide overuse of common antibiotics and antifungals in clinical practice and agriculture. Biofilms harbour antimicrobial-resistant subpopulations, which make their antimicrobial treatment even more challenging. Nanoparticle-based technologies have recently been shown to successfully overcome antimicrobial resistance in both planktonic and biofilms phenotypes. This results from the combination of novel nanomaterial research and classic antimicrobial therapies which promise to deliver a whole new generation of high-performance active nanocarrier systems. This review discusses the latest developments of promising nanotechnologies with applications against resistant pathogens and evaluates their potential and feasibility for use in novel antimicrobial therapies.
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Affiliation(s)
- Paul J Weldick
- Department of Chemistry and Biochemistry, University of Hull, Hull, HU6 7RX, UK
| | - Anheng Wang
- Department of Chemistry and Biochemistry, University of Hull, Hull, HU6 7RX, UK
| | - Ahmed F Halbus
- Department of Chemistry, College of Science, University of Babylon, Hilla, Iraq
| | - Vesselin N Paunov
- Department of Chemistry, Nazarbayev University, Kabanbay Baryr Ave. 53, Nur-sultan city, 010000, Kazakhstan.
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Arjmand B, Kokabi Hamidpour S, Rabbani Z, Tayanloo-Beik A, Rahim F, Aghayan HR, Larijani B. Organ on a Chip: A Novel in vitro Biomimetic Strategy in Amyotrophic Lateral Sclerosis (ALS) Modeling. Front Neurol 2022; 12:788462. [PMID: 35111126 PMCID: PMC8802668 DOI: 10.3389/fneur.2021.788462] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 12/20/2021] [Indexed: 12/20/2022] Open
Abstract
Amyotrophic lateral sclerosis is a pernicious neurodegenerative disorder that is associated with the progressive degeneration of motor neurons, the disruption of impulse transmission from motor neurons to muscle cells, and the development of mobility impairments. Clinically, muscle paralysis can spread to other parts of the body. Hence it may have adverse effects on swallowing, speaking, and even breathing, which serves as major problems facing these patients. According to the available evidence, no definite treatment has been found for amyotrophic lateral sclerosis (ALS) that results in a significant outcome, although some pharmacological and non-pharmacological treatments are currently applied that are accompanied by some positive effects. In other words, available therapies are only used to relieve symptoms without any significant treatment effects that highlight the importance of seeking more novel therapies. Unfortunately, the process of discovering new drugs with high therapeutic potential for ALS treatment is fraught with challenges. The lack of a broad view of the disease process from early to late-stage and insufficiency of preclinical studies for providing validated results prior to conducting clinical trials are other reasons for the ALS drug discovery failure. However, increasing the combined application of different fields of regenerative medicine, especially tissue engineering and stem cell therapy can be considered as a step forward to develop more novel technologies. For instance, organ on a chip is one of these technologies that can provide a platform to promote a comprehensive understanding of neuromuscular junction biology and screen candidate drugs for ALS in combination with pluripotent stem cells (PSCs). The structure of this technology is based on the use of essential components such as iPSC- derived motor neurons and iPSC-derived skeletal muscle cells on a single miniaturized chip for ALS modeling. Accordingly, an organ on a chip not only can mimic ALS complexities but also can be considered as a more cost-effective and time-saving disease modeling platform in comparison with others. Hence, it can be concluded that lab on a chip can make a major contribution as a biomimetic micro-physiological system in the treatment of neurodegenerative disorders such as ALS.
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Affiliation(s)
- Babak Arjmand
- Cell Therapy and Regenerative Medicine Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
- *Correspondence: Babak Arjmand
| | - Shayesteh Kokabi Hamidpour
- Cell Therapy and Regenerative Medicine Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Rabbani
- Cell Therapy and Regenerative Medicine Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Akram Tayanloo-Beik
- Cell Therapy and Regenerative Medicine Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Fakher Rahim
- Health Research Institute, Thalassemia, and Hemoglobinopathies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Hamid Reza Aghayan
- Cell Therapy and Regenerative Medicine Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Bagher Larijani
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
- Bagher Larijani
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11
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Westfall S, Dinh DM, Pasinetti GM. Investigation of Potential Brain Microbiome in Alzheimer's Disease: Implications of Study Bias. J Alzheimers Dis 2021; 75:559-570. [PMID: 32310171 DOI: 10.3233/jad-191328] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Dysbiotic microbiota in the gastrointestinal tract promotes and aggravates neurodegenerative disorders. Alzheimer's disease (AD) has been shown to correlate to dysbiotic bacteria and the immune, metabolic, and endocrine abnormalities associated with abnormal gut-brain-axis signaling. Recent reports also indicate that brain dysbacteriosis may play a role in AD pathogenesis. OBJECTIVE To evaluate the presence and differences of brain-region dependent microbiomes in control and AD subjects and the contribution of study bias. METHODS Two independent cohorts of postmortem AD brain samples were collected from separate locations, processed with different extraction protocols and investigated for the presence of bacterial DNA indicative of a brain microbiome with V4 16S next generation sequencing. RESULTS In both cohorts, few differences between the control and AD groups were observed in terms of alpha and beta diversities, phyla and genera proportions. Independent of study in both AD and control subjects the most abundant phyla were Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Variations in beta diversity between hippocampal and cerebellum samples were observed indicating an impact of brain region on the presence of microbial DNA. Importantly, differences in alpha and beta diversities between the two independent cohorts were found indicating a significant cohort- and processing-dependent effect on the microbiome. Finally, there were cohort-specific correlations between the gut microbiome and subject demographics indicate that postmortem interval may have a significant impact on brain microbiome determination. CONCLUSIONS Regardless of the study bias, this study concludes that bacterial DNA can be isolated from the human brain suggesting that a brain microbiome may exist; however, more studies are required to understand the variation in AD.
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Affiliation(s)
- Susan Westfall
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Giulio Maria Pasinetti
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Geriatric Research, Education and Clinical Center, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA
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12
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Melnick M, Gonzales P, LaRocca TJ, Song Y, Wuu J, Benatar M, Oskarsson B, Petrucelli L, Dowell RD, Link CD, Prudencio M. Application of a bioinformatic pipeline to RNA-seq data identifies novel viruslike sequence in human blood. G3-GENES GENOMES GENETICS 2021; 11:6259144. [PMID: 33914880 PMCID: PMC8661426 DOI: 10.1093/g3journal/jkab141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/20/2021] [Indexed: 12/11/2022]
Abstract
Numerous reports have suggested that infectious agents could play a role in neurodegenerative diseases, but specific etiological agents have not been convincingly demonstrated. To search for candidate agents in an unbiased fashion, we have developed a bioinformatic pipeline that identifies microbial sequences in mammalian RNA-seq data, including sequences with no significant nucleotide similarity hits in GenBank. Effectiveness of the pipeline was tested using publicly available RNA-seq data and in a reconstruction experiment using synthetic data. We then applied this pipeline to a novel RNA-seq dataset generated from a cohort of 120 samples from amyotrophic lateral sclerosis patients and controls, and identified sequences corresponding to known bacteria and viruses, as well as novel virus-like sequences. The presence of these novel virus-like sequences, which were identified in subsets of both patients and controls, were confirmed by quantitative RT-PCR. We believe this pipeline will be a useful tool for the identification of potential etiological agents in the many RNA-seq datasets currently being generated.
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Affiliation(s)
- Marko Melnick
- Integrative Physiology, University of Colorado, Boulder, Colorado, 80303, USA
| | - Patrick Gonzales
- Integrative Physiology, University of Colorado, Boulder, Colorado, 80303, USA
| | - Thomas J LaRocca
- Department of Health and Exercise Science, Center for Healthy Aging, Colorado State University, Fort Collins, Colorado, 80523, USA
| | - Yuping Song
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, Florida, 32224, USA
| | - Joanne Wuu
- Department of Neurology, University of Miami, Miami, Florida, 33136, USA
| | - Michael Benatar
- Department of Neurology, University of Miami, Miami, Florida, 33136, USA
| | - Björn Oskarsson
- Department of Neurology, Mayo Clinic, 4500 San Pablo Road, Jacksonville FL, 32224, USA
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, Florida, 32224, USA.,Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida, 32224, USA
| | - Robin D Dowell
- BioFrontiers Institute and Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado, 80303, USA
| | - Christopher D Link
- Integrative Physiology, University of Colorado, Boulder, Colorado, 80303, USA.,Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado, 80303, USA
| | - Mercedes Prudencio
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, Florida, 32224, USA.,Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida, 32224, USA
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13
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Levi I, Gurevich M, Perlman G, Magalashvili D, Menascu S, Bar N, Godneva A, Zahavi L, Chermon D, Kosower N, Wolf BC, Malka G, Lotan-Pompan M, Weinberger A, Yirmiya E, Rothschild D, Leviatan S, Tsur A, Didkin M, Dreyer S, Eizikovitz H, Titngi Y, Mayost S, Sonis P, Dolev M, Stern Y, Achiron A, Segal E. Potential role of indolelactate and butyrate in multiple sclerosis revealed by integrated microbiome-metabolome analysis. Cell Rep Med 2021; 2:100246. [PMID: 33948576 PMCID: PMC8080254 DOI: 10.1016/j.xcrm.2021.100246] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 01/18/2021] [Accepted: 03/18/2021] [Indexed: 12/12/2022]
Abstract
Multiple sclerosis (MS) is an immune-mediated disease whose precise etiology is unknown. Several studies found alterations in the microbiome of individuals with MS, but the mechanism by which it may affect MS is poorly understood. Here we analyze the microbiome of 129 individuals with MS and find that they harbor distinct microbial patterns compared with controls. To study the functional consequences of these differences, we measure levels of 1,251 serum metabolites in a subgroup of subjects and unravel a distinct metabolite signature that separates affected individuals from controls nearly perfectly (AUC = 0.97). Individuals with MS are found to be depleted in butyrate-producing bacteria and in bacteria that produce indolelactate, an intermediate in generation of the potent neuroprotective antioxidant indolepropionate, which we found to be lower in their serum. We identify microbial and metabolite candidates that may contribute to MS and should be explored further for their causal role and therapeutic potential.
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Affiliation(s)
- Izhak Levi
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Michael Gurevich
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Gal Perlman
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - David Magalashvili
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Shay Menascu
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
- Sackler School of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Noam Bar
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Anastasia Godneva
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Liron Zahavi
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Danyel Chermon
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Noa Kosower
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Bat Chen Wolf
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Gal Malka
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Maya Lotan-Pompan
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Adina Weinberger
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Erez Yirmiya
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Daphna Rothschild
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sigal Leviatan
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Avishag Tsur
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Maria Didkin
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Sapir Dreyer
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Hen Eizikovitz
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Yamit Titngi
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Sue Mayost
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Polina Sonis
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Mark Dolev
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Yael Stern
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Anat Achiron
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
- Sackler School of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Eran Segal
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
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14
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Källstig E, McCabe BD, Schneider BL. The Links between ALS and NF-κB. Int J Mol Sci 2021; 22:3875. [PMID: 33918092 PMCID: PMC8070122 DOI: 10.3390/ijms22083875] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 04/06/2021] [Accepted: 04/06/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease wherein motor neuron degeneration leads to muscle weakness, progressive paralysis, and death within 3-5 years of diagnosis. Currently, the cause of ALS is unknown but, as with several neurodegenerative diseases, the potential role of neuroinflammation has become an increasingly popular hypothesis in ALS research. Indeed, upregulation of neuroinflammatory factors have been observed in both ALS patients and animal models. One such factor is the inflammatory inducer NF-κB. Besides its connection to inflammation, NF-κB activity can be linked to several genes associated to familial forms of ALS, and many of the environmental risk factors of the disease stimulate NF-κB activation. Collectively, this has led many to hypothesize that NF-κB proteins may play a role in ALS pathogenesis. In this review, we discuss the genetic and environmental connections between NF-κB and ALS, as well as how this pathway may affect different CNS cell types, and finally how this may lead to motor neuron degeneration.
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Affiliation(s)
| | | | - Bernard L. Schneider
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, 1015 Lausanne, Switzerland; (E.K.); (B.D.M.)
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15
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Bedarf JR, Beraza N, Khazneh H, Özkurt E, Baker D, Borger V, Wüllner U, Hildebrand F. Much ado about nothing? Off-target amplification can lead to false-positive bacterial brain microbiome detection in healthy and Parkinson's disease individuals. MICROBIOME 2021; 9:75. [PMID: 33771222 PMCID: PMC8004470 DOI: 10.1186/s40168-021-01012-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 02/02/2021] [Indexed: 05/02/2023]
Abstract
BACKGROUND Recent studies suggested the existence of (poly-)microbial infections in human brains. These have been described either as putative pathogens linked to the neuro-inflammatory changes seen in Parkinson's disease (PD) and Alzheimer's disease (AD) or as a "brain microbiome" in the context of healthy patients' brain samples. METHODS Using 16S rRNA gene sequencing, we tested the hypothesis that there is a bacterial brain microbiome. We evaluated brain samples from healthy human subjects and individuals suffering from PD (olfactory bulb and pre-frontal cortex), as well as murine brains. In line with state-of-the-art recommendations, we included several negative and positive controls in our analysis and estimated total bacterial biomass by 16S rRNA gene qPCR. RESULTS Amplicon sequencing did detect bacterial signals in both human and murine samples, but estimated bacterial biomass was extremely low in all samples. Stringent reanalyses implied bacterial signals being explained by a combination of exogenous DNA contamination (54.8%) and false positive amplification of host DNA (34.2%, off-target amplicons). Several seemingly brain-enriched microbes in our dataset turned out to be false-positive signals upon closer examination. We identified off-target amplification as a major confounding factor in low-bacterial/high-host-DNA scenarios. These amplified human or mouse DNA sequences were clustered and falsely assigned to bacterial taxa in the majority of tested amplicon sequencing pipelines. Off-target amplicons seemed to be related to the tissue's sterility and could also be found in independent brain 16S rRNA gene sequences. CONCLUSIONS Taxonomic signals obtained from (extremely) low biomass samples by 16S rRNA gene sequencing must be scrutinized closely to exclude the possibility of off-target amplifications, amplicons that can only appear enriched in biological samples, but are sometimes assigned to bacterial taxa. Sequences must be explicitly matched against any possible background genomes present in large quantities (i.e., the host genome). Using close scrutiny in our approach, we find no evidence supporting the hypothetical presence of either a brain microbiome or a bacterial infection in PD brains. Video abstract.
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Affiliation(s)
- Janis R. Bedarf
- Department of Neurology, University Hospital Bonn, Venusberg Campus 1, 53127 Bonn, Germany
- Gut Microbes & Health, Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UA UK
| | - Naiara Beraza
- Gut Microbes & Health, Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UA UK
| | - Hassan Khazneh
- Department of Neurology, University Hospital Bonn, Venusberg Campus 1, 53127 Bonn, Germany
| | - Ezgi Özkurt
- Gut Microbes & Health, Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UA UK
- Earlham Institute, Norwich Research Park, Norwich, Norfolk, NR4 7UA UK
| | - David Baker
- Gut Microbes & Health, Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UA UK
| | - Valeri Borger
- Department of Neurosurgery, University Hospital Bonn, Venusberg Campus 1, 53127 Bonn, Germany
| | - Ullrich Wüllner
- Department of Neurology, University Hospital Bonn, Venusberg Campus 1, 53127 Bonn, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Venusberg Campus 2, 53127 Bonn, Germany
| | - Falk Hildebrand
- Gut Microbes & Health, Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UA UK
- Earlham Institute, Norwich Research Park, Norwich, Norfolk, NR4 7UA UK
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16
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Boddy SL, Giovannelli I, Sassani M, Cooper-Knock J, Snyder MP, Segal E, Elinav E, Barker LA, Shaw PJ, McDermott CJ. The gut microbiome: a key player in the complexity of amyotrophic lateral sclerosis (ALS). BMC Med 2021; 19:13. [PMID: 33468103 PMCID: PMC7816375 DOI: 10.1186/s12916-020-01885-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 12/09/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Much progress has been made in mapping genetic abnormalities linked to amyotrophic lateral sclerosis (ALS), but the majority of cases still present with no known underlying cause. Furthermore, even in families with a shared genetic abnormality there is significant phenotypic variability, suggesting that non-genetic elements may modify pathogenesis. Identification of such disease-modifiers is important as they might represent new therapeutic targets. A growing body of research has begun to shed light on the role played by the gut microbiome in health and disease with a number of studies linking abnormalities to ALS. MAIN BODY The microbiome refers to the genes belonging to the myriad different microorganisms that live within and upon us, collectively known as the microbiota. Most of these microbes are found in the intestines, where they play important roles in digestion and the generation of key metabolites including neurotransmitters. The gut microbiota is an important aspect of the environment in which our bodies operate and inter-individual differences may be key to explaining the different disease outcomes seen in ALS. Work has begun to investigate animal models of the disease, and the gut microbiomes of people living with ALS, revealing changes in the microbial communities of these groups. The current body of knowledge will be summarised in this review. Advances in microbiome sequencing methods will be highlighted, as their improved resolution now enables researchers to further explore differences at a functional level. Proposed mechanisms connecting the gut microbiome to neurodegeneration will also be considered, including direct effects via metabolites released into the host circulation and indirect effects on bioavailability of nutrients and even medications. CONCLUSION Profiling of the gut microbiome has the potential to add an environmental component to rapidly advancing studies of ALS genetics and move research a step further towards personalised medicine for this disease. Moreover, should compelling evidence of upstream neurotoxicity or neuroprotection initiated by gut microbiota emerge, modification of the microbiome will represent a potential new avenue for disease modifying therapies. For an intractable condition with few current therapeutic options, further research into the ALS microbiome is of crucial importance.
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Affiliation(s)
- Sarah L Boddy
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Ilaria Giovannelli
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Matilde Sassani
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Johnathan Cooper-Knock
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Michael P Snyder
- Stanford Center for Genomics and Personalized Medicine, Stanford University School of Medicine, Stanford, USA
| | - Eran Segal
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot, Israel
| | - Eran Elinav
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
- Division of Cancer-Microbiome Research, DKFZ, Heidelberg, Germany
| | - Lynne A Barker
- Centre for Behavioural Science and Applied Psychology, Sheffield Hallam University, Sheffield, UK
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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17
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Carrasco L, Pisa D, Alonso R. Polymicrobial Infections and Neurodegenerative Diseases. CURRENT CLINICAL MICROBIOLOGY REPORTS 2020. [DOI: 10.1007/s40588-020-00139-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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18
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Pisa D, Alonso R, Carrasco L. Parkinson's Disease: A Comprehensive Analysis of Fungi and Bacteria in Brain Tissue. Int J Biol Sci 2020; 16:1135-1152. [PMID: 32174790 PMCID: PMC7053320 DOI: 10.7150/ijbs.42257] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 11/22/2019] [Indexed: 12/21/2022] Open
Abstract
Parkinson's disease (PD) is characterized by motor disorders and the destruction of dopaminergic neurons in the substantia nigra pars compacta. In addition to motor disability, many patients with PD present a spectrum of clinical symptoms, including cognitive decline, psychiatric alterations, loss of smell and bladder dysfunction, among others. Neuroinflammation is one of the most salient features of PD, but the nature of the trigger remains unknown. A plausible mechanism to explain inflammation and the range of clinical symptoms in these patients is the presence of systemic microbial infection. Accordingly, the present study provides extensive evidence for the existence of mixed microbial infections in the central nervous system (CNS) of patients with PD. Assessment of CNS sections by immunohistochemistry using specific antibodies revealed the presence of both fungi and bacteria. Moreover, different regions of the CNS were positive for a variety of microbial morphologies, suggesting infection by a number of microorganisms. Identification of specific fungal and bacterial species in different CNS regions from six PD patients was accomplished using nested PCR analysis and next-generation sequencing, providing compelling evidence of polymicrobial infections in the CNS of PD. Most of the fungal species identified belong to the genera Botrytis, Candida, Fusarium and Malassezia. Some relevant bacterial genera were Streptococcus and Pseudomonas, with most bacterial species belonging to the phyla Actinobacteria and Proteobacteria. Interestingly, we noted similarities and differences between the microbiota present in the CNS of patients with PD and that in other neurodegenerative diseases. Overall, our observations lend strong support to the concept that mixed microbial infections contribute to or are a risk factor for the neuropathology of PD. Importantly, these results provide the basis for effective treatments of this disease using already approved and safe antimicrobial therapeutics.
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Affiliation(s)
| | | | - Luis Carrasco
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM). c/Nicolás Cabrera, 1. Universidad Autónoma de Madrid. Cantoblanco. 28049 Madrid. Spain
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19
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Alonso R, Pisa D, Carrasco L. Brain Microbiota in Huntington's Disease Patients. Front Microbiol 2019; 10:2622. [PMID: 31798558 PMCID: PMC6861841 DOI: 10.3389/fmicb.2019.02622] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 10/28/2019] [Indexed: 12/27/2022] Open
Abstract
One of the most important challenges facing medical science is to better understand the cause of neuronal pathology in neurodegenerative diseases. Such is the case for Huntington's disease (HD), a genetic disorder primarily caused by a triplet expansion in the Huntingtin gene (HTT). Although aberrant HTT is expressed from embryogenesis, it remains puzzling as to why the onset of disease symptoms manifest only after several decades of life. In the present study, we investigated the possibility of microbial infection in brain tissue from patients with HD, reasoning that perhaps mutated HTT could be deleterious for immune cells and neural tissue, and could facilitate microbial colonization. Using immunohistochemistry approaches, we observed a variety of fungal structures in the striatum and frontal cortex of seven HD patients. Some of these fungi were found in close proximity to the nucleus, or even as intranuclear inclusions. Identification of the fungal species was accomplished by next-generation sequencing (NGS). Interestingly, some genera, such as Ramularia, appeared unique to HD patients, and have not been previously described in other neurodegenerative diseases. Several bacterial species were also identified both by PCR and NGS. Notably, a curved and filamentous structure that immunoreacts with anti-bacterial antibodies was characteristic of HD brains and has not been previously observed in brain tissue from neurodegenerative patients. Prevalent bacterial genera included Pseudomonas, Acinetobacter, and Burkholderia. Collectively, our results represent the first attempt to identify the brain microbiota in HD. Our observations suggest that microbial colonization may be a risk factor for HD and might explain why the onset of the disease appears after several decades of life. Importantly, they may open a new field of investigation and could help in the design of new therapeutic strategies for this devastating disorder.
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Affiliation(s)
- Ruth Alonso
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Diana Pisa
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Luis Carrasco
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
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