The diagnosis of Parkinson's disease (PD) is based on clinical features and differently to the common opinion that detecting this condition is easy, seminal clinicopathological studies have shown ...that up one-fourth of patients diagnosed as PD during life has an alternative diagnosis at postmortem. The misdiagnosis is even higher when only the initial diagnosis is considered, since the diagnostic accuracy improves by time, during follow-up visits. Given that the confirmation of the diagnosis of PD can be only obtained through neuropathology, to improve and facilitate the diagnostic-therapeutic workup in PD, a number of criteria and guidelines have been introduced in the last three decades. In the present paper, we will critically re-appraise the main diagnostic criteria proposed for PD, with particular attention to the recently published criteria by the International Parkinson and Movement Disorder Society (MDS) task force, underlying their novelty and focusing on the diagnostic issues still open. We also emphasize that the MDS-PD criteria encompass the two main previous sets of diagnostic criteria (United Kingdom PD Society Brain Bank and Gelb's criteria), introducing at the same time new aspects as the use of non-motor symptoms as additional diagnostic features, and the adoption of the concept of prodromal PD, crucial to enroll in clinical trials PD patients in the very early phase of the disease. To better understand the real diffusion of the new MDS-PD diagnostic criteria among neurologists, we have also collected selective opinions of sixteen movement disorder experts from various world regions on their practical approach for the clinical diagnosis of PD. Results from this brief survey showed that, although innovative and complete, the revised diagnostic criteria produced by MDS task force are still scarcely employed among clinicians. We believe that both national and international scientific societies should operate in the future for a broader diffusion of these criteria with specific initiatives, including dedicated events and teaching courses.
The intestinal microbiota influence neurodevelopment, modulate behavior, and contribute to neurological disorders. However, a functional link between gut bacteria and neurodegenerative diseases ...remains unexplored. Synucleinopathies are characterized by aggregation of the protein α-synuclein (αSyn), often resulting in motor dysfunction as exemplified by Parkinson’s disease (PD). Using mice that overexpress αSyn, we report herein that gut microbiota are required for motor deficits, microglia activation, and αSyn pathology. Antibiotic treatment ameliorates, while microbial re-colonization promotes, pathophysiology in adult animals, suggesting that postnatal signaling between the gut and the brain modulates disease. Indeed, oral administration of specific microbial metabolites to germ-free mice promotes neuroinflammation and motor symptoms. Remarkably, colonization of αSyn-overexpressing mice with microbiota from PD-affected patients enhances physical impairments compared to microbiota transplants from healthy human donors. These findings reveal that gut bacteria regulate movement disorders in mice and suggest that alterations in the human microbiome represent a risk factor for PD.
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•Gut microbes promote α-synuclein-mediated motor deficits and brain pathology•Depletion of gut bacteria reduces microglia activation•SCFAs modulate microglia and enhance PD pathophysiology•Human gut microbiota from PD patients induce enhanced motor dysfunction in mice
Signals from gut microbes are required for the neuroinflammatory responses as well as hallmark gastrointestinal and α-synuclein-dependent motor deficits in a model of Parkinson’s disease.
Non-motor features of Parkinson disease Schapira, Anthony H V; Chaudhuri, K Ray; Jenner, Peter
Nature reviews. Neuroscience,
07/2017, Volume:
18, Issue:
7
Journal Article
Peer reviewed
Open access
Many of the motor symptoms of Parkinson disease (PD) can be preceded, sometimes for several years, by non-motor symptoms that include hyposmia, sleep disorders, depression and constipation. These ...non-motor features appear across the spectrum of patients with PD, including individuals with genetic causes of PD. The neuroanatomical and neuropharmacological bases of non-motor abnormalities in PD remain largely undefined. Here, we discuss recent advances that have helped to establish the presence, severity and effect on the quality of life of non-motor symptoms in PD, and the neuroanatomical and neuropharmacological mechanisms involved. We also discuss the potential for the non-motor features to define a prodrome that may enable the early diagnosis of PD.
Emerging evidence suggests that gut microbiome composition alterations affect neurodegeneration through neuroinflammation in the pathogenesis of Parkinson's disease (PD). Here, we evaluate gut ...microbiota alterations and host cytokine responses in a population of Taiwanese patients with PD.
Fecal microbiota communities from 80 patients with PD and 77 age and gender-matched controls were assessed by sequencing the V3-V4 region of the 16S ribosomal RNA gene. Diet and comorbidities were controlled in the analyses. Plasma concentrations of IL-1β, IL-2, IL-4, IL-6, IL-13, IL-18, GM-CSF, IFNγ, and TNFα were measured by a multiplex immunoassay and relationships between microbiota, clinical characteristics, and cytokine levels were analyzed in the PD group. We further examined the cytokine changes associated with the altered gut microbiota seen in patients with PD in another independent cohort of 120 PD patients and 120 controls.
Microbiota from patients with PD was altered relative to controls and dominated by Verrucomicrobia, Mucispirillum, Porphyromonas, Lactobacillus, and Parabacteroides. In contrast, Prevotella was more abundant in controls. The abundances of Bacteroides were more increased in patients with non-tremor PD subtype than patients with tremor subtype. Bacteroides abundance was correlated with motor symptom severity defined by UPDRS part III motor scores (rho = 0.637 95% confidence interval 0.474 to 0.758, P < 0.01). Altered microbiota was correlated with plasma concentrations of IFNγ and TNFα. There was a correlation between Bacteroides and plasma level of TNFα (rho = 0.638 95% CI: 0.102-0.887, P = 0.02); and a correlation between Verrucomicrobia abundance and plasma concentrations of IFNγ (rho = 0.545 95% CI - 0.043-0.852, P = 0.05). The elevated plasma cytokine responses were confirmed in an additional independent 120 patients with PD and 120 controls (TNFα: PD vs. control 8.51 ± 4.63 pg/ml vs. 4.82 ± 2.23 pg/ml, P < 0.01; and IFNγ: PD vs. control: 38.45 ± 7.12 pg/ml vs. 32.79 ± 8.03 pg/ml, P = 0.03).
This study reveals altered gut microbiota in PD and its correlation with clinical phenotypes and severity in our population. The altered plasma cytokine profiles associated with gut microbiome composition alterations suggest aberrant immune responses may contribute to inflammatory processes in PD.
A path for α-synuclein from the gut to the nervous system. Enteroendocrine cells (EECs) express α-synuclein and connect to α-synuclein-containing enteric nerves. This circuit provides a possible ...route for bacteria or toxins in the gut to induce abnormal α-synuclein formation that could transfer to the nervous system to initiate Parkinson’s disease.
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•Parkinson’s disease is characterized by Lewy bodies in the brain and peripheral nerves.•Misfolding and aggregation of α-synuclein leads to Lewy body formation.•Misfolded α-synuclein can spread in a prion-like fashion.•Epidemiological and experimental evidence suggest PD arises in the gut.•Like neurons, enteroendocrine cells express α-synuclein and could be a source of PD.
Parkinson’s disease (PD) is a debilitating neurodegenerative condition associated with tremor, rigidity, dementia, and gastrointestinal symptoms such as constipation, nausea and vomiting. The pathological hallmarks of PD are Lewy bodies and neurites in the brain and peripheral nerves. The major constituent of Lewy bodies is the neuronal protein α-synuclein. Misfolding of α-synuclein confers prion-like properties enabling its spread from cell to cell. Misfolded α-synuclein also serves as a template and induces misfolding of endogenous α-synuclein in recipient cells leading to the formation of oligomers that progress to fibrils and eventually Lewy bodies. Accumulating evidence suggests that PD may arise in the gut. Clinically, gastrointestinal symptoms often appear in patients before other neurological signs and aggregates of α-synuclein have been found in enteric nerves of PD patients. Importantly, patients undergoing vagotomy have a reduced risk of developing PD. Experimentally, abnormal forms of α-synuclein appear in enteric nerves before they appear in the brain and injection of abnormal α-synuclein into the wall of the intestine spreads to the vagus nerve. Ingested toxins and alterations in gut microbiota can induce α-synuclein aggregation and PD, however, it is not known how PD starts. Recently, it has been shown that sensory cells of the gut known as enteroendocrine cells (EECs) contain α-synuclein and synapse with enteric nerves, thus providing a connection from the gut to the brain. It is possible that abnormal α-synuclein first develops in EECs and spreads to the nervous system.
The classic view portrays Parkinson disease (PD) as a motor disorder resulting from loss of substantia nigra pars compacta dopaminergic neurons. Multiple studies, however, describe prodromal, ...non-motor dysfunctions that affect the quality of life of patients who subsequently develop PD. These prodromal dysfunctions comprise a wide array of gastrointestinal motility disorders including dysphagia, delayed gastric emptying and chronic constipation. The histological hallmark of PD - misfolded α-synuclein aggregates that form Lewy bodies and neurites - is detected in the enteric nervous system prior to clinical diagnosis, suggesting that the gastrointestinal tract and its neural (vagal) connection to the central nervous system could have a major role in disease aetiology. This Review provides novel insights on the pathogenesis of PD, including gut-to-brain trafficking of α-synuclein as well as the newly discovered nigro-vagal pathway, and highlights how vagal connections from the gut could be the conduit by which ingested environmental pathogens enter the central nervous system and ultimately induce, or accelerate, PD progression. The pathogenic potential of various environmental neurotoxicants and the suitability and translational potential of experimental animal models of PD will be highlighted and appraised. Finally, the clinical manifestations of gastrointestinal involvement in PD and medications will be discussed briefly.
Induced pluripotent stem cells (iPS cells) are a promising source for a cell-based therapy to treat Parkinson's disease (PD), in which midbrain dopaminergic neurons progressively degenerate. However, ...long-term analysis of human iPS cell-derived dopaminergic neurons in primate PD models has never been performed to our knowledge. Here we show that human iPS cell-derived dopaminergic progenitor cells survived and functioned as midbrain dopaminergic neurons in a primate model of PD (Macaca fascicularis) treated with the neurotoxin MPTP. Score-based and video-recording analyses revealed an increase in spontaneous movement of the monkeys after transplantation. Histological studies showed that the mature dopaminergic neurons extended dense neurites into the host striatum; this effect was consistent regardless of whether the cells were derived from patients with PD or from healthy individuals. Cells sorted by the floor plate marker CORIN did not form any tumours in the brains for at least two years. Finally, magnetic resonance imaging and positron emission tomography were used to monitor the survival, expansion and function of the grafted cells as well as the immune response in the host brain. Thus, this preclinical study using a primate model indicates that human iPS cell-derived dopaminergic progenitors are clinically applicable for the treatment of patients with PD.
There is growing awareness within the scientific community of the strong connection between the inflammation in the intestine and the pathogenesis of Parkinson's disease (PD). In previous studies we ...developed a PD animal model exposing pup rats to permethrin (PERM) pesticide. Here, we intended to explore whether in our animal model there were changes in gut permeability, fecal microbiota and hepatic injury. Moreover, we tested if the co-treatment with an electrolyzed reduced (ERW) was effective to protect against alterations induced by PERM. Rats (from postnatal day 6 to 21) were gavaged daily with PERM, PERM+ERW or vehicle and gut, liver and feces were analyzed in 2-months-old rats. Increased gut permeability, measured by FITC-dextran assay, was detected in PERM group compared to control and PERM+ERW groups. In duodenum and ileum, concentration of occludin was higher in control group than those measured in PERM group, whereas only in duodenum ZO-1 was higher in control than those measured in PERM and PERM+ERW groups. Number of inflammatory focis and neutrophils as well as iNOS protein levels were higher in livers of PERM-treated rats than in those of PERM+ERW and control rats. Fecal microbiota analysis revealed that Lachnospira was less abundant and Defluviitaleaceae more abundant in the PERM group, whereas the co-treatment with ERW was protective against PERM treatment since the abundances in Lachnospira and Defluviitaleaceae were similar to those in the control group. Higher abundances of butyrate- producing bacteria such as Blautia, U.m. of Lachnospiraceae family, U.m. of Ruminococcaceae family, Papillibacter, Roseburia, Intestinimonas, Shuttleworthia together with higher butyric acid levels were detected in PERM+ERW group compared to the other groups. In conclusion, the PD animal model showed increased intestinal permeability together with hepatic inflammation correlated with altered gut microbiota. The positive effects of ERW co-treatment observed in gut, liver and brain of rats were linked to changes on gut microbiota.
Parkinson's disease (PD) is a common neurodegenerative disorder primarily characterized by the death of dopaminergic neurons that project from the substantia nigra
. Although the molecular bases for ...PD development are still little defined, extensive evidence from human samples and animal models support the involvement of inflammation in onset or progression. However, the exact trigger for this response remains unclear. Here, we provide a systematic review of the cellular mediators, i.e., microglia, astroglia and endothelial cells. We also discuss the genetic and transcriptional control of inflammation in PD and the immunomodulatory role of dopamine and reactive oxygen species. Finally, we summarize the preclinical and clinical approaches targeting neuroinflammation in PD.
Genome-wide association studies have discovered hundreds of loci associated with complex brain disorders, but it remains unclear in which cell types these loci are active. Here we integrate ...genome-wide association study results with single-cell transcriptomic data from the entire mouse nervous system to systematically identify cell types underlying brain complex traits. We show that psychiatric disorders are predominantly associated with projecting excitatory and inhibitory neurons. Neurological diseases were associated with different cell types, which is consistent with other lines of evidence. Notably, Parkinson's disease was genetically associated not only with cholinergic and monoaminergic neurons (which include dopaminergic neurons) but also with enteric neurons and oligodendrocytes. Using post-mortem brain transcriptomic data, we confirmed alterations in these cells, even at the earliest stages of disease progression. Our study provides an important framework for understanding the cellular basis of complex brain maladies, and reveals an unexpected role of oligodendrocytes in Parkinson's disease.
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