scholarly journals Dysregulation of the Gut-Brain Axis, Dysbiosis and Influence of Numerous Factors on Gut Microbiota Associated Parkinson’s Disease

2020 ◽  
Vol 19 (2) ◽  
pp. 233-247 ◽  
Author(s):  
Gagandeep Kaur ◽  
Tapan Behl ◽  
Simona Bungau ◽  
Arun Kumar ◽  
Md Sahab Uddin ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Immune Response ◽  
Parkinson's Disease ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Neurological Disorders ◽  
Neurodegenerative Disorder ◽  
Microbial Composition ◽  
Neuroendocrine Mechanisms ◽  
The Brain

Background: Parkinson’s disease (PD) has been one of the substantial social, medical concern and, burdens of the present time. PD is a gradually devastating neurodegenerative disorder of the neurological function marked with αsynucleinopathy affecting numerous regions of the brain-gut axis, as well as the central, enteric, and autonomic nervous system. Its etiology is a widely disputed topic. Objective: This review emphasizes to find out the correlation among the microbial composition and the observable disturbances in the metabolites of the microbial species and its impact on the immune response, which may have a concrete implication on the occurrence, persistence and, pathophysiology of PD via the gut-brain axis. Methods: An in-depth research and the database was developed from the available peer reviewed articles till date (March 2020) utilizing numerous search engines like PubMed, MEDLINE and, other internet sources. Results: Progressively increasing shreds of evidence have proved the fact that dysbiosis in the gut microbiome plays a central role in many neurological disorders, such as PD. Indeed, a disordered microbiome-gut-brain axis in PD could be focused on gastrointestinal afflictions that manifest primarily several years prior to the diagnosis, authenticating a concept wherein the pathological pathway progresses from the intestine reaching the brain. Conclusion: The microbiota greatly affects the bidirectional interaction between the brain and the gut via synchronized neurological, immunological, and neuroendocrine mechanisms. It can be concluded that a multitude of factors discussed in this review steadily induce the onset of dysbacteriosis that may exacerbate the etiologic mechanism of Parkinson’s disease.

scholarly journals What Is the Evidence that Parkinson’s Disease Is a Prion Disorder, Which Originates in the Gut?

2018 ◽  
Vol 19 (11) ◽  
pp. 3573 ◽  
Author(s):  
Małgorzata Kujawska ◽  
Jadwiga Jodynis-Liebert
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Nervous System ◽  
Neurodegenerative Disorder ◽  
Human Subjects ◽  
Gastrointestinal Symptoms ◽  
Convincing Evidence ◽  
Substantia Nigra Pars Compacta ◽  
Motor Nucleus ◽  
The Brain

Parkinson’s disease (PD) is a neurodegenerative disorder resulting from degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc). PD is characterized by motor dysfunctions as well as gastrointestinal symptoms and mental impairment. The pathological hallmark of PD is an accumulation of misfolded α-synuclein aggregates within the brain. The etiology of PD and related synucleinopathy is poorly understood, but recently, the hypothesis that α-synuclein pathology spreads in a prion-like fashion originating in the gut has gained much scientific attention. A crucial clue was the appearance of constipation before the onset of motor symptoms, gut dysbiosis and synucleinopathy in PD patients. Another line of evidence, demonstrating accumulation of α-synuclein within the peripheral autonomic nervous system (PANS), including the enteric nervous system (ENS), and the dorsal motor nucleus of the vagus (DMV) support the concept that α-synuclein can spread from the ENS to the brain by the vagus nerve. The decreased risk of PD following truncal vagotomy supports this. The convincing evidence of the prion-like behavior of α-synuclein came from postmortem observations that pathological α-synuclein inclusions appeared in healthy grafted neurons. In this review, we summarize the available data from human subjects’ research and animal experiments, which seem to be the most suggestive for explaining the hypotheses.

scholarly journals Brain-first versus body-first Parkinson’s disease: a multimodal imaging case-control study

Brain ◽  
2020 ◽  
Vol 143 (10) ◽  
pp. 3077-3088 ◽  
Author(s):  
Jacob Horsager ◽  
Katrine B Andersen ◽  
Karoline Knudsen ◽  
Casper Skjærbæk ◽  
Tatyana D Fedorova ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Locus Coeruleus ◽  
Multimodal Imaging ◽  
Case Control ◽  
Autonomic Nervous ◽  
Transit Times ◽  
The Brain

Abstract Parkinson’s disease is characterized by the presence of abnormal, intraneuronal α-synuclein aggregates, which may propagate from cell-to-cell in a prion-like manner. However, it remains uncertain where the initial α-synuclein aggregates originate. We have hypothesized that Parkinson’s disease comprises two subtypes. A brain-first (top-down) type, where α-synuclein pathology initially arises in the brain with secondary spreading to the peripheral autonomic nervous system; and a body-first (bottom-up) type, where the pathology originates in the enteric or peripheral autonomic nervous system and then spreads to the brain. We also hypothesized that isolated REM sleep behaviour disorder (iRBD) is a prodromal phenotype for the body-first type. Using multimodal imaging, we tested the hypothesis by quantifying neuronal dysfunction in structures corresponding to Braak stages I, II and III involvement in three distinct patient groups. We included 37 consecutive de novo patients with Parkinson’s disease into this case-control PET study. Patients with Parkinson’s disease were divided into 24 RBD-negative (PDRBD−) and 13 RBD-positive cases (PDRBD+) and a comparator group of 22 iRBD patients. We used 11C-donepezil PET/CT to assess cholinergic (parasympathetic) innervation, 123I-metaiodobenzylguanidine (MIBG) scintigraphy to measure cardiac sympathetic innervation, neuromelanin-sensitive MRI to measure the integrity of locus coeruleus pigmented neurons, and 18F-dihydroxyphenylalanine (FDOPA) PET to assess putaminal dopamine storage capacity. Colon volume and transit times were assessed with CT scans and radiopaque markers. Imaging data from the three groups were interrogated with ANOVA and Kruskal-Wallis tests corrected for multiple comparisons. The PDRBD− and PDRBD+ groups showed similar marked reductions in putaminal FDOPA-specific uptake, whereas two-thirds of iRBD patients had normal scans (P < 10−13, ANOVA). When compared to the PDRBD− patients, the PDRBD+ and iRBD patients showed reduced mean MIBG heart:mediastinum ratios (P < 10−5, ANOVA) and colon 11C-donepezil standard uptake values (P = 0.008, ANOVA). The PDRBD+ group trended towards a reduced mean MRI locus coeruleus: pons ratio compared to PDRBD− (P = 0.07, t-test). In comparison to the other groups, the PDRBD+ group also had enlarged colon volumes (P < 0.001, ANOVA) and delayed colonic transit times (P = 0.01, Kruskal-Wallis). The combined iRBD and PDRBD+ patient data were compatible with a body-first trajectory, characterized by initial loss of cardiac MIBG signal and 11C-colonic donepezil signal followed by loss of putaminal FDOPA uptake. In contrast, the PDRBD− data were compatible with a brain-first trajectory, characterized by primary loss of putaminal FDOPA uptake followed by a secondary loss of cardiac MIBG signal and 11C-donepezil signal. These findings support the existence of brain-first and body-first subtypes of Parkinson’s disease.

scholarly journals Alpha-synuclein alters the faecal viromes of rats in a gut-initiated model of Parkinson’s disease

2021 ◽  
Author(s):  
S. R. Stockdale ◽  
L. A. Draper ◽  
S. M. O’Donovan ◽  
W. Barton ◽  
O. O’Sullivan ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Nervous System ◽  
Lewy Body ◽  
Neurological Disorder ◽  
Alpha Synuclein ◽  
Observational Period ◽  
Β Diversity ◽  
Potential Trigger ◽  
The Brain

AbstractParkinson’s disease (PD) is a chronic neurological disorder associated with the misfolding of alpha-synuclein (α-syn) into Lewy body aggregates within nerve cells that contribute to their neurodegeneration. Recent evidence suggests α-syn aggregation may begin in the gut and travel to the brain along the vagus nerve, with microbes a potential trigger initiating the misfolding of α-syn. However, changes in the gut virome in response to α-syn alterations have not been investigated. In this study, we show longitudinal changes in the faecal virome of rats administered either monomeric or preformed fibrils (PFF) of α-syn directly into their enteric nervous system. Differential changes in rat viromes were observed when comparing monomeric and PFF α-syn. The virome β-diversity changes after α-syn treatment were compounded by the addition of LPS as an adjunct. Changes in the diversity of rat faecal viromes were observed after one month and did not resolve within the study’s five month observational period. Overall, these results suggest that microbiome alterations associated with PD may, partially, be reactive to host α-syn associated changes.

Parkinson's Disease

2019 ◽  
pp. 252-273 ◽  
Author(s):  
Vaibhav Walia ◽  
Ashish Gakkhar ◽  
Munish Garg
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Dopaminergic Neurons ◽  
Older Patients ◽  
Neurodegenerative Disorder ◽  
Progressive Loss ◽  
The Brain

Parkinson's disease (PD) is a neurodegenerative disorder in which a progressive loss of the dopaminergic neurons occurs. The loss of the neurons is most prominent in the substantia nigra region of the brain. The prevalence of PD is much greater among the older patients suggesting the risk of PD increases with the increase of age. The exact cause of the neurodegeneration in PD is not known. In this chapter, the authors introduce PD, demonstrate its history, pathogenesis, neurobiology, sign and symptoms, diagnosis, and pharmacotherapy.

scholarly journals The Rotenone Models Reproducing Central and Peripheral Features of Parkinson’s Disease

NeuroSci ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Ikuko Miyazaki ◽  
Masato Asanuma
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Nervous System ◽  
Peripheral Nervous System ◽  
Neurodegenerative Disorder ◽  
Rem Sleep Behavior Disorder ◽  
Experimental Models ◽  
Motor Symptoms ◽  
Sleep Behavior ◽  
Disease Modifying Drugs

Parkinson’s disease (PD) is a complex, multi-system, neurodegenerative disorder; PD patients exhibit motor symptoms (such as akinesia/bradykinesia, tremor, rigidity, and postural instability) due to a loss of nigrostriatal dopaminergic neurons, and non-motor symptoms such as hyposmia, autonomic disturbance, depression, and REM sleep behavior disorder (RBD), which precedes motor symptoms. Pathologically, α-synuclein deposition is observed in the central and peripheral nervous system of sporadic PD patients. To clarify the mechanism of neurodegeneration in PD and to develop treatment to slow or stop PD progression, there is a great need for experimental models which reproduce neurological features of PD. Animal models exposed to rotenone, a commonly used pesticide, have received most attention since Greenamyre and his colleagues reported that chronic exposure to rotenone could reproduce the anatomical, neurochemical, behavioral, and neuropathological features of PD. In addition, recent studies demonstrated that rotenone induced neuropathological change not only in the central nervous system but also in the peripheral nervous system in animals. In this article, we review rotenone models especially focused on reproducibility of central and peripheral multiple features of PD. This review also highlights utility of rotenone models for investigation of PD pathogenesis and development of disease-modifying drugs for PD in future.

scholarly journals α-Synuclein pre-formed fibrils induce prion-like protein aggregation and neurotoxicity in C. elegans models of Parkinson's disease

2021 ◽  
Author(s):  
Merry Chen ◽  
Julie Vincent ◽  
Alexis Ezeanii ◽  
Saurabh Wakade ◽  
Shobha Yerigenahally ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neurodegenerative Disorder ◽  
Motor Deficit ◽  
Rodent Models ◽  
Neuron Degeneration ◽  
C Elegans ◽  
Dopaminergic Neurodegeneration ◽  
Disease Mechanisms ◽  
The Brain

Parkinson's disease (PD) is a debilitating neurodegenerative disorder characterized by progressive motor decline and the aggregation of α-synuclein protein. Growing evidence suggests that α-synuclein aggregates may spread from neurons of the digestive tract to the brain in a prion-like manner. While rodent models have recapitulated gut-to-brain α-synuclein transmission, animal models that are amenable to high-throughput investigations are needed to facilitate the discovery of disease mechanisms. Here we describe the first C. elegans models in which feeding with α-synuclein pre-formed fibrils (PFFs) induced prion-like dopamine neuron degeneration and seeding of aggregation of human α-synuclein expressed in the host. PFF acceleration of α-synuclein aggregation in C. elegans muscle cells was associated with a progressive motor deficit, whereas feeding with α-synuclein monomer produced much milder effects. RNAi-mediated knockdown of the C. elegans syndecan sdn-1, and enzymes involved in heparan sulfate proteoglycan biosynthesis, afforded protection from PFF-induced seeding of aggregation and toxicity, as well as dopaminergic neurodegeneration. This work offers new models by which to investigate gut-derived α-synuclein spreading and propagation of disease.

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