alpha-synuclein and Constipation

Parkinson's disease (PD) is a neurodegenerative disorder whose aetiology remains unclear: degeneration involves several neurotransmission systems, resulting in a heterogeneous disease characterized by motor and non-motor symptoms. PD causes progressive disability that responds only to symptomatic therapies. Future advances include neuroprotective strategies for use in at-risk populations before the clinical onset of disease, hence the continuing need to identify reliable biomarkers that can facilitate the clinical diagnosis of PD. In this evaluative review, we summarize information on potential diagnostic biomarkers for use in the clinical and preclinical stages of PD.

Topics: alpha-Synuclein; Biomarkers; Brain; Cognition Disorders; Constipation; Depression; Early Diagnosis; Genetic Predisposition to Disease; Humans; Inflammation; Levodopa; Metabolomics; Microbiota; Movement Disorders; Neuroimaging; Olfaction Disorders; Parkinson Disease; REM Sleep Behavior Disorder; Symptom Assessment; Vision Disorders

Early involvement of gut is observed in Parkinson's disease (PD) and symptoms such as constipation may precede motor symptoms. α-Synuclein pathology is extensively evident in the gut and appears to follow a rostrocaudal gradient. The gut may act as the starting point of PD pathology with spread toward the central nervous system. This spread of the synuclein pathology raises the possibility of prion-like propagation in PD pathogenesis. Recently, the role of gut microbiota in PD pathogenesis has received attention and some phenotypic correlation has also been shown. The extensive involvement of the gut in PD even in its early stages has led to the evaluation of enteric α-synuclein as a possible biomarker of early PD. The clinical manifestations of gastrointestinal dysfunction in PD include malnutrition, oral and dental disorders, sialorrhea, dysphagia, gastroparesis, constipation, and defecatory dysfunction. These conditions are quite distressing for the patients and require relevant investigations and adequate management. Treatment usually involves both pharmacological and non-pharmacological measures. One important aspect of gut dysfunction is its contribution to the clinical fluctuations in PD. Dysphagia and gastroparesis lead to inadequate absorption of oral anti-PD medications. These lead to response fluctuations, particularly delayed-on and no-on, and there is significant relationship between levodopa pharmacokinetics and gastric emptying in patients with PD. Therefore, in such cases, alternative routes of administration or drug delivery systems may be required.

Topics: alpha-Synuclein; Antiparkinson Agents; Constipation; Deglutition Disorders; Enteric Nervous System; Gastrointestinal Absorption; Gastrointestinal Microbiome; Gastrointestinal Tract; Gastroparesis; Humans; Malnutrition; Parkinson Disease; Sialorrhea

Epidemiological studies show correlations between constipation and development of Parkinson's disease (PD); however, few studies have explored the association between constipation and dementia with Lewy bodies (DLB), Parkinson's disease dementia (PDD), and multiple system atrophy (MSA). We sought to explore the lifelong association of constipation and PD, DLB, PDD, and MSA (α-Synucleinopathies), compared to age- and sex-matched controls.. Using the Rochester Epidemiology Project (REP), we established an incident cohort of clinically defined α-synucleinopathies. A movement-disorder specialist reviewed all medical charts to establish clinical diagnoses.. We identified 453 incident cases of clinically diagnosed α-synucleinopathies and an identical number of age- and sex-matched controls in Olmsted County (MN), 1991-2010. There were 303 cases of PD; 80, DLB; 54, PDD; and 16, MSA. Approximately 50% of α-synucleinopathies of all types reported constipation, compared to 27% in controls. The earliest pre-motor onset constipation was in DLB (median, 3.76 years prior to α-synucleinopathies motor-symptom onset); latest onset post-motor constipation was in PD (median, 5.15 years after motor-symptom onset). PD also had the highest longstanding constipation rate (18.2%). All α-synucleinopathies had higher odds of constipation compared to controls, except for MSA (p = 0.09), likely due to a limited sample size.. PD, DLB, and PDD had higher odds of constipation compared to controls; PD had the most widespread onset of lifelong constipation, both longstanding and pre- or post-motor onset symptoms. Our results indicate that constipation rates do not differ among α-synucleinopathies but do differ in terms of temporal onset compared to disease onset.

Topics: alpha-Synuclein; Chronic Disease; Constipation; Dementia; Humans; Lewy Body Disease; Minnesota; Multiple System Atrophy; Parkinson Disease; Synucleinopathies

Non-motor symptoms in Parkinson's disease (PD) are common, difficult to treat, and significantly impair quality of life. One prevalent non-motor symptom is constipation, which can precede the diagnosis of PD by years or even decades. Constipation has been underexplored in animal models of PD and lacks specific therapies. This assay utilizes a Drosophila model of PD in which human alpha-synuclein is expressed under a pan-neuronal driver. Flies expressing alpha-synuclein develop the hallmark features of PD: the loss of dopaminergic neurons, motor impairment, and alpha-synuclein inclusions. This protocol outlines a method for studying constipation in these flies. Flies are placed on fly food with a blue color additive overnight and then transferred to standard food the following day. They are subsequently moved to new vials with standard fly food every hour for 8 h. Before each transfer, the percentage of blue-colored fecal spots compared to the total fecal spots on the vial wall is calculated. Control flies that lack alpha-synuclein expel all the blue dye hours before flies expressing alpha-synuclein. Additionally, the passage of blue-colored food from the gut can be monitored with simple photography. The simplicity of this assay enables its use in forward genetic or chemical screens to identify modifiers of constipation in Drosophila.

Topics: alpha-Synuclein; Animals; Constipation; Disease Models, Animal; Dopaminergic Neurons; Drosophila; Humans; Parkinson Disease; Quality of Life

Prodromal constipation (PC) at Parkinson's disease (PD) onset may mark a distinct neurodegenerative trajectory; accordingly, presenting phenotype, biochemical signature, and progression of PD patients with PC (PD + PC) might differ from those without (PDwoPC). We compared the clinical-biochemical profile of de novo PD patients with and without PC, and the respective mid-term progression, to establish the grouping effect of PC.. Motor and non-motor scores were collected at diagnosis in n = 57 PD + PC patients and n = 73 PDwoPC. Paired CSF biomarkers (α-synuclein, amyloid and tau peptides, lactate, CSF/serum albumin ratio or AR) were assessed into a smaller sample and n = 46 controls. Clinical progression was estimated as Hoehn and Yahr stage (HY) and levodopa equivalent daily dose (LEDD) change 2.06 ± 1.35 years after diagnosis.. At onset, PD + PC patients had higher HY and MDS-UPDRS-part III scores, and higher CSF AR. PDwoPC had higher Non-Motor Symptoms Scale domain-2 score, and lower CSF α-synuclein level. At follow-up, PD + PC had greater LEDD.. PC identifies a group of de novo patients with more severe motor impairment, possible blood brain barrier disruption, and greater dopaminergic requirement at mid-term; conversely, de novo PDwoPC patients had prominent fatigue, and pronounced central synucleinopathy.

Topics: alpha-Synuclein; Biomarkers; Constipation; Humans; Lactates; Levodopa; Parkinson Disease; Serum Albumin

Introduction: Excessive alcohol consumption results in neuroadaptation, neurodegeneration, and differential expression of numerous genes.\ Objective: To determine the relationship between the expression of the alpha synuclein gene (SNCA) in blood, single nucleotide variant (SNV) in its promoter region, and chronic constipation in people with problems of alcohol consumption.\ Materials and methods: The sample consisted of 35 controls and 27 cases selected according to the score obtained with the AUDIT tool. For the diagnosis of constipation, the Rome IV criteria were applied. Nucleic acid extraction was performed from peripheral blood and the expression of the gene was evaluated by qPCR, protein quantification by ELISA, and the presence of SNV in the promoter region of the gene by Sanger sequencing.\ Results: We observed a relative gene overexpression of SNCA mRNA in the case group, which was not related to the diagnosis of chronic constipation. There was 4.8 times greater risk of presenting constipation in the group of cases. Besides, nine single nucleotide variants were found in a segment of the promoter region of the gene rich in CpG regulatory sequences with similar frequency between the groups while a variant was identified in position -2171, which is not reported in GenBank for variants and whose genotype A/T was associated with increased expression of SNCA mRNA.\ Conclusion: We evidenced an overexpression of alpha synuclein mRNA in people with problems of alcohol consumption that was not related to the diagnosis of chronic constipation.. Introducción. El consumo excesivo de alcohol resulta en neuroadaptación, neurodegeneración y expresión diferencial de numerosos genes. Objetivo. Determinar la relación entre la expresión del gen de la alfa sinucleína (SNCA) en sangre, las variantes de nucleótido único (Single Nucleotide Variant, SNV) en su región promotora y el estreñimiento crónico en personas con problemas de consumo de alcohol. Materiales y métodos. La muestra estuvo conformada por 35 controles y 27 casos, seleccionados según el puntaje obtenido con la herramienta AUDIT. En el diagnóstico del estreñimiento se aplicaron los criterios de Roma IV. La extracción de ácidos nucleicos se hizo a partir de sangre periférica y se evaluó la expresión del gen mediante qPCR, la cuantificación proteica por ELISA y la presencia de SNV en la región promotora del gen por la secuenciación de Sanger. Resultados. Se observó sobreexpresión génica relativa de ARNm del gen SNCA en el grupo de casos sin relación con el estreñimiento crónico. Se evidenció un riesgo 4,8 veces mayor de presentar estreñimiento en el grupo de casos. Se encontraron nueve variantes de nucleótido simple en un segmento de la región promotora del gen rica en secuencias reguladoras CpG, con frecuencia similar entre los grupos, y se detectó una variante en la posición -2171 que no se encuentra reportada en GenBank para variantes clínicas y cuyo genotipo A/T se relacionó con el incremento de la expresión del ARNm del SNCA. Conclusión. En personas con problemas de consumo de alcohol se evidenció la sobreexpresión del ARNm de alfa sinucleína, lo cual no se relacionó con el diagnóstico de estreñimiento crónico.

Topics: Adult; Alcoholism; alpha-Synuclein; Case-Control Studies; Chronic Disease; Colombia; Constipation; Female; Gastrointestinal Motility; Gene Expression; Gene Frequency; Humans; Inflammation; Leukocytes, Mononuclear; Male; Polymorphism, Single Nucleotide; Prevalence; Promoter Regions, Genetic; RNA, Messenger; Urban Population; Young Adult

Parkinson's disease (PD) is a progressive neurodegenerative disorder thought to be caused by accumulation of α-synuclein (α-syn) within the brain, autonomic nerves, and the enteric nervous system (ENS). Involvement of the ENS in PD often precedes the onset of the classic motor signs of PD by many years at a time when severe constipation represents a major morbidity. Studies conducted in vitro and in vivo, have shown that squalamine, a zwitterionic amphipathic aminosterol, originally isolated from the liver of the dogfish shark, effectively displaces membrane-bound α-syn.. Here we explore the electrophysiological effect of squalamine on the gastrointestinal (GI) tract of mouse models of PD engineered to express the highly aggregating A53T human α-syn mutant.. GI motility and in vivo response to oral squalamine in PD model mice and controls were assessed using an in vitro tissue motility protocol and via fecal pellet output. Vagal afferent response to squalamine was measured using extracellular mesenteric nerve recordings from the jejunum. Whole cell patch clamp was performed to measure response to squalamine in the myenteric plexus.. Squalamine effectively restores disordered colonic motility in vivo and within minutes of local application to the bowel. We show that topical squalamine exposure to intrinsic primary afferent neurons (IPANs) of the ENS rapidly restores excitability.. These observations may help to explain how squalamine may promote gut propulsive activity through local effects on IPANs in the ENS, and further support its possible utility in the treatment of constipation in patients with PD.

Topics: alpha-Synuclein; Animals; Cholestanols; Constipation; Disease Models, Animal; Electrophysiological Phenomena; Enteric Nervous System; Gastrointestinal Motility; Jejunum; Mice; Mice, Transgenic; Mutant Proteins; Myenteric Plexus; Neurons, Afferent; Parkinson Disease; Patch-Clamp Techniques; Vagus Nerve

Gastrointestinal (GI) motility dysfunction is the most common non-motor symptom of Parkinson's disease (PD). Studies have indicated that GI motility functions are impaired before the onset of PD.. To investigate the underlying mechanism of PD-induced GI dysmotility in MPTP (1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine)-induced animal model.. C57BL/6 mice were administered with or without a selective dopamine neurotoxin, MPTP, to induce parkinsonian symptoms. In addition to in vivo studies, in vitro experiments were also conducted in colon specimens using l-methyl-4-phenylpyridinium (MPP. MPTP-induced PD mice showed decreased expression of nuclear factor erythroid 2-related factor (Nrf2) and its target phase II genes in gastric and colon neuromuscular tissues. Decreased levels of tetrahydrobiopterin (BH

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; 1-Methyl-4-phenylpyridinium; alpha-Synuclein; Animals; Biopterins; Blotting, Western; Colon; Constipation; Disease Models, Animal; Enzyme Inhibitors; Gastric Emptying; Gastrointestinal Motility; Gene Expression Regulation; Heme Oxygenase-1; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; MPTP Poisoning; NF-E2-Related Factor 2; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase Type I; Parkinson Disease; Parkinsonian Disorders; Tyrosine 3-Monooxygenase

The aims of this study were to investigate the effect of colonic electrical stimulation (CES) on delayed colonic transit in Parkinson's disease (PD) model induced by rotenone and its possible mechanisms.. Sprague-Dawley male rats were implanted with a pair of electrodes on the serosa at the proximal colon and rotenone was subcutaneously injected for 6 weeks to induce the PD model. Behavior activity, stool volume and open-field test were recorded during the injection. Colonic propulsion rate was measured 6 weeks after rotenone injection. Colon samples of all rats were collected for the measurement of phosphorylated alpha-synuclein, choline acetyltransferase (CHAT), neuronal nitric oxide synthase (nNOS), and tyrosine hydroxylase (TH). The protocols of control rats were the same as the PD rats except that no electrodes were implanted and no rotenone was injected.. (1) Rotenone-induced PD rats demonstrated weight loss, significant decrease of the dopaminergic neurons in substantia nigra, and impairment of colon movement. (2) CES significantly accelerated the delayed colonic transmit (91.67 ± 5.58% vs 51.33 ± 4.18%), superior to Macrogol-4000. (3) CES significantly upregulated the expression of CHAT, nNOS and TH protein in colon of PD rats. (4) In colon of PD rats, the phosphorylated alpha-synuclein was significantly upregulated, but CES had no significant effect on phosphorylated alpha-synuclein.. Our data show that CES can normalize the delayed colonic transit and this normalization may attribute to affecting enteric excitatory and inhibitory neurons.

Topics: alpha-Synuclein; Animals; Choline O-Acetyltransferase; Colon; Constipation; Disease Models, Animal; Electric Stimulation; Enteric Nervous System; Gastrointestinal Motility; Intestine, Small; Male; Neurons; Nitric Oxide Synthase; Nitric Oxide Synthase Type I; Parkinson Disease; Rats; Rats, Sprague-Dawley; Rotenone; Substantia Nigra; Tyrosine 3-Monooxygenase

α-Synucleinopathies are neurodegenerative diseases that are characterized pathologically by α-synuclein inclusions in neurons and glia. The pathologic contribution of glial α-synuclein in these diseases is not well understood. Glial α-synuclein may be of particular importance in multiple system atrophy (MSA), which is defined pathologically by glial cytoplasmic α-synuclein inclusions. We have previously described Drosophila models of neuronal α-synucleinopathy, which recapitulate key features of the human disorders. We have now expanded our model to express human α-synuclein in glia. We demonstrate that expression of α-synuclein in glia alone results in α-synuclein aggregation, death of dopaminergic neurons, impaired locomotor function, and autonomic dysfunction. Furthermore, co-expression of α-synuclein in both neurons and glia worsens these phenotypes as compared to expression of α-synuclein in neurons alone. We identify unique transcriptomic signatures induced by glial as opposed to neuronal α-synuclein. These results suggest that glial α-synuclein may contribute to the burden of pathology in the α-synucleinopathies through a cell type-specific transcriptional program. This new Drosophila model system enables further mechanistic studies dissecting the contribution of glial and neuronal α-synuclein in vivo, potentially shedding light on mechanisms of disease that are especially relevant in MSA but also the α-synucleinopathies more broadly.

Topics: alpha-Synuclein; Animals; Animals, Genetically Modified; Cell Death; Constipation; Disease Models, Animal; Dopaminergic Neurons; Drosophila; Humans; Movement Disorders; Nerve Degeneration; Neurodegenerative Diseases; Neuroglia; Protein Aggregation, Pathological; Transcription, Genetic; Transcriptome

Topics: alpha-Synuclein; Brain; Constipation; Dopamine Plasma Membrane Transport Proteins; Humans; Parkinson Disease; Primary Dysautonomias

Hyposmia plays an important role in the early and differential diagnosis of Parkinson's disease (PD); however its underlying mechanism is poorly understood. The aim of the present study is to explore the clinical phenotypic and genotypic correlation of hyposmia in Chinese PD patients.. Olfactory function evaluated by 16-item odor identification test from Sniffin' Sticks (SS-16) of 218 Chinese Han PD patients and 110 healthy controls was compared. 186 patients also had the genetic information of two positive GWAS-linked SNCA loci (rs11931074, rs894278) previously validated in our center. The associations of hyposmia with SNCA variants and disease phenotypic characteristics including motor symptoms (UPDRS motor score) and other common NMSs (clinical possible RBD-cpRBD, depression and chronic constipation) were analyzed.. Nearly 39.9% (n = 87) of PD reported subjective complaints of hyposmia, while 60.1% (n = 131) patients had objective hyposmia (SS-16 < 8.3). Patients with hyposmia had older age (p = 0.001), later onset age (p = 0.020), higher SCOPA-AUT scores (p = 0.011), higher percentage of chronic constipation (p = 0.001) and cpRBD (p = 0.003). Binary logistic regression analysis revealed that ageing (OR = 1.058; 95%CI: 1.012-1.106; p = 0.013), chronic constipation (OR = 2.072; 95% CI: 1.157-3.710; p = 0.014) and cpRBD (OR = 2.234; 95% CI: 1.040-4.797; p = 0.039) were independent influential factors of hyposmia in Chinese PD patients. Subgroup analysis of patients with both clinical and genetic results demonstrated that after adjusting for age, sex, chronic constipation and cpRBD, rs11931074 TT genotype may increase the risk of hyposmia in PD (OR = 3.24 95% CI = 1.23-8.51, p = 0.017) compared to GG genotype via an additive model.. Age, cpRBD, chronic constipation and SNCA rs11931074 may correlate with hyposmia in Chinese PD patients.

Topics: Age of Onset; Aged; Aged, 80 and over; alpha-Synuclein; Asian People; Constipation; Female; Genetic Variation; Genotype; Humans; Male; Middle Aged; Odorants; Olfaction Disorders; Parkinson Disease; Risk Factors

Parkinson's disease is a neurodegenerative disorder characterized by motor and nonmotor impairments, including constipation. The hallmark pathological features of Parkinson's disease are Lewy bodies and neurites, of which aggregated α-synuclein is a major constituent. Frequently, Lewy pathology is identified in the distal gut of constipated Parkinson's disease patients. The neurons that innervate the distal gut that express α-synuclein have not been identified. We used multiple-labeling immunohistochemistry and anterograde tracing to quantify which neurons projecting to the guinea pig rectum and human colon expressed α-synuclein in their axons. α-Synuclein-immunoreactivity was present in 24 ± 0.7% of somatostatin (SOM)-immunoreactive (IR) varicosities; 20 ± 4.3% of substance P (SP)-IR varicosities and 9 ± 1.3% vasoactive intestinal polypeptide (VIP)-IR varicosities in guinea pig rectal myenteric ganglia. However, α-synuclein-immunoreactivity was localized in significantly more vesicular acetylcholine transporter (VAChT)-IR varicosities (88 ± 3%, P < 0.001). Of SOM-IR, SP-IR, and VIP-IR varicosities that lacked VAChT-immunoreactivity, only 1 ± 0.3%, 0 ± 0.3%, and 0% contained α-synuclein-immunoreactivity, respectively. 71 ± 0.8% of VAChT-IR varicosities in myenteric ganglia of human colon were α-synuclein-IR. In guinea pig rectal myenteric ganglia, α-synuclein- and VAChT-immunoreactivity coexisted in 15 ± 1.4% of biotinamide-labeled extrinsic varicosities; only 1 ± 0.3% of biotinamide-labeled extrinsic varicosities contained α-synuclein-immunoreactivity without VAChT-immunoreactivity. α-Synuclein expression in axons to the distal gut correlates closely with expression of the cholinergic marker, VAChT. This is the first report of cell-selective α-synuclein expression in the nervous system. Our results suggest cholinergic neurons in the gut may be vulnerable in Parkinson's disease.

Topics: Adult; Aged; alpha-Synuclein; Animals; Antibody Specificity; Axons; Cholinergic Neurons; Colon; Constipation; Female; Guinea Pigs; Humans; Immunohistochemistry; Lewy Bodies; Male; Middle Aged; Myenteric Plexus; Parkinson Disease; Rectum; Reproducibility of Results; Vesicular Acetylcholine Transport Proteins

It is proposed that alpha-synucleinopathy initially affects the medulla oblongata and then progresses to more rostral brain areas ("Braak hypothesis"). According to this hypothesis, substantia nigra is affected in the later stages of PD. Another region affected in the earlier stages was reported to be olfactory bulb, although the following processes were not described in detail. On the other hand, several lines of evidence suggest that non-motor symptoms including constipation, depression, REM-sleep behavior disorder (RBD) and hyposmia may be prodromal symptoms in PD. The pathological staging postulated by the Braak hypothesis is in good agreement with the fact that these non-motor symptoms precede motor symptoms in PD, because affected brain areas in the early stages, such as dorsal vagal nucleus, locus ceruleus and olfactory bulb, are related to these non-motor features. Recently, it was reported that although half of brains corresponded to the Braak hypothesis, there were a high proportion of cases which did not fit the Braak's staging system and majority of the latter demonstrated amygdale-predominant alpha-synucleinopathy. It was also demonstrated that the Lewy pathology in olfactory bulb was closely related to the presence of alpha-synuclein pathology in amygdala. The amygdala is one of the main systems in odor perception and in PD, cortical neurons in corticomedial complex of amygdale, which have major olfactory connections, are selectively affected even in the early stages of the disease. We recently obtained the data suggesting that metabolic changes in the amygdala were associated with low scores in odor identification test. These data suggest that not only the olfactory bulb, but also the amygdala is also responsible for hyposmia in PD and that there may be another pathological process, which starts from the olfactory bulb and involves the amygdala.

Topics: alpha-Synuclein; Amygdala; Constipation; Depression; Disease Progression; Humans; Olfaction Disorders; Olfactory Bulb; Parkinson Disease; Positron-Emission Tomography; REM Sleep Behavior Disorder

Topics: Aged; alpha-Synuclein; Biopsy; Case-Control Studies; Colon; Constipation; Enteric Nervous System; Humans; Immunohistochemistry; Male; Nerve Degeneration; Parkinson Disease; Pilot Projects; Submucous Plexus

The presynaptic protein alpha-synuclein (alphaSyn) has been implicated in both familial and sporadic forms of Parkinson's disease. We examined whether human alphaSyn-overexpressing mice under Thy1 promoter (Thy1-alphaSyn) display alterations of colonic function. Basal fecal output was decreased in Thy1-alphaSyn mice fed ad libitum. Fasted/refed Thy1-alphaSyn mice had a slower distal colonic transit than the wild-type mice, as monitored by 2.2-fold increase in time to expel an intracolonic bead and 2.9-fold higher colonic fecal content. By contrast, Thy1-alphaSyn mice had an increased fecal response to novelty stress and corticotropin releasing factor injected intraperipherally. These results indicate that Thy1-alphaSyn mice display altered basal and stress-stimulated propulsive colonic motility and will be a useful model to study gut dysfunction associated with Parkinson's disease.

Topics: alpha-Synuclein; Animals; Colon; Constipation; Corticotropin-Releasing Hormone; Disease Models, Animal; Feces; Gastrointestinal Motility; Gene Expression; Humans; Male; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Transgenic; Parkinson Disease; Thy-1 Antigens