Infections and Changes in Commensal Bacteria and the Pathogenesis of Parkinson's Disease.

The cause of Parkinson's disease (PD) is unknown, but environmental factors are purported to influence risk. Interest in PD as a sequel of infection dates back to reports of parkinsonism arising from encephalitis lethargica. The objective of this paper is to review the literature as it relates to infections and changes in microbiome and the genesis of PD.

Gut-Derived Sterile Inflammation and Parkinson's Disease.

The etiology of Parkinson's disease (PD) is unknown, but evidence is increasing that there is a prominent inflammatory component to the illness. Epidemiological, genetic, and preclinical evidence support a role for gut-derived sterile inflammation. Pro-inflammatory bacteria are over-represented in the PD gut microbiota.

Experimental colitis promotes sustained, sex-dependent, T-cell-associated neuroinflammation and parkinsonian neuropathology.

Background: The etiology of sporadic Parkinson's disease (PD) remains uncertain, but genetic, epidemiological, and physiological overlap between PD and inflammatory bowel disease suggests that gut inflammation could promote dysfunction of dopamine-producing neurons in the brain. Mechanisms behind this pathological gut-brain effect and their interactions with sex and with environmental factors are not well understood but may represent targets for therapeutic intervention.

Methods: We sought to identify active inflammatory mechanisms which could potentially contribute to neuroinflammation and neurological disease in colon biopsies and peripheral blood immune cells from PD patients.

Mild Cognitive Impairment as an Early Landmark in Huntington's Disease.

As one of the clinical triad in Huntington's disease (HD), cognitive impairment has not been widely accepted as a disease stage indicator in HD literature. This work aims to study cognitive impairment thoroughly for prodromal HD individuals with the data from a 12-year observational study to determine whether Mild Cognitive Impairment (MCI) in HD gene-mutation carriers is a defensible indicator of early disease. Prodromal HD gene-mutation carriers evaluated annually at one of 32 worldwide sites from September 2002 to April 2014 were evaluated for MCI in six cognitive domains.

APOE4 is Associated with Differential Regional Vulnerability to Bioenergetic Deficits in Aged APOE Mice.

The ε4 allele of apolipoprotein E (APOE) is the dominant genetic risk factor for late-onset Alzheimer's disease (AD). However, the reason for the association between APOE4 and AD remains unclear. While much of the research has focused on the ability of the apoE4 protein to increase the aggregation and decrease the clearance of Aβ, there is also an abundance of data showing that APOE4 negatively impacts many additional processes in the brain, including bioenergetics.

Recent Advances in the Treatment of Huntington's Disease: Targeting DNA and RNA.

Huntington's disease is a dominantly inherited neurodegenerative disease caused by an unstable expanded trinucleotide repeat at the short end of the fourth chromosome. Central nervous system pathology begins in the striatum, eventually affecting the entire brain and occurs consequent to multiple intracellular derangements. The proximate cause is a mutant protein with an elongated polyglutamine tract.

Chronic stress-induced gut dysfunction exacerbates Parkinson's disease phenotype and pathology in a rotenone-induced mouse model of Parkinson's disease.

Recent evidence provides support for involvement of the microbiota-gut-brain axis in Parkinson's disease (PD) pathogenesis. We propose that a pro-inflammatory intestinal milieu, due to intestinal hyper-permeability and/or microbial dysbiosis, initiates or exacerbates PD pathogenesis. One factor that can cause intestinal hyper-permeability and dysbiosis is chronic stress which has been shown to accelerate neuronal degeneration and motor deficits in Parkinsonism rodent models.

Role of TLR4 in the gut-brain axis in Parkinson's disease: a translational study from men to mice.

Objective: Recent evidence suggesting an important role of gut-derived inflammation in brain disorders has opened up new directions to explore the possible role of the gut-brain axis in neurodegenerative diseases. Given the prominence of dysbiosis and colonic dysfunction in patients with Parkinson's disease (PD), we propose that toll-like receptor 4 (TLR4)-mediated intestinal dysfunction could contribute to intestinal and central inflammation in PD-related neurodegeneration.

Design: To test this hypothesis we performed studies in both human tissue and a murine model of PD.

The enteric nervous system in PD: gateway, bystander victim, or source of solutions.

Apart from the characteristic and progressive motor- and movement-related problems, Parkinson's disease (PD) patients also suffer from several non-motor symptoms, including gastrointestinal dysfunction. The fact that the enteric nervous system (ENS) controls motility and that one of the typical PD hallmarks, α-synuclein-positive deposits, has also been found in the intestinal wall have rendered the ENS and the gut a popular subject of study in the context of PD. The possibility that these deposits could serve as an early biomarker is obviously of tremendous medical benefit but also the idea that the gut may possibly be a gateway via which the disease is initiated and progressively makes its way via the peripheral nerves to the central nervous system has increased the interest in the ENS-PD link.

The Potential Role of Gut-Derived Inflammation in Multiple System Atrophy.

Background: Recent evidence suggests that Parkinson's disease (PD) is associated with intestinal microbiota dysbiosis, abnormal intestinal permeability, and intestinal inflammation.

Objective: Our study aimed to determine if these gut abnormalities are present in another synucleinopathy, multiple system atrophy (MSA).

Methods: In six MSA and 11 healthy control subjects, we performed immunohistochemistry studies of colonic sigmoid mucosa to evaluate the intestinal barrier marker Zonula Occludens-1 and the endotoxin-related inflammation marker Toll-like-receptor-4 expression.

A randomized, double-blind, placebo-controlled trial of coenzyme Q10 in Huntington disease.

Objective: To test the hypothesis that chronic treatment of early-stage Huntington disease (HD) with high-dose coenzyme Q10 (CoQ) will slow the progressive functional decline of HD.

Methods: We performed a multicenter randomized, double-blind, placebo-controlled trial. Patients with early-stage HD (n = 609) were enrolled at 48 sites in the United States, Canada, and Australia from 2008 to 2012.

Gut Microbiota Regulate Motor Deficits and Neuroinflammation in a Model of Parkinson's Disease.

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).

Similar α-Synuclein staining in the colon mucosa in patients with Parkinson's disease and controls.

Background: The gut is proposed as a starting point of idiopathic IPD, but the presence of α-synuclein in the IPD colon mucosa is debated.

Objectives: The objective of this study was to evaluate if α-synuclein in the colon mucosa can serve as a biomarker of IPD.

Methods: Immunohistochemistry was used to locate and quantify in a blinded approach α-synuclein in the mucosa from biopsies of the right and left colon in 19 IPD patients and 8 controls.

Pridopidine for the treatment of Huntington's disease.

Introduction: Huntington's disease is a rare dominantly-inherited neurodegenerative disease with motor, cognitive and behavioral manifestations. It results from an expanded unstable trinucleotide repeat in the coding region of the huntingtin gene. Treatment is symptomatic, but a poor evidence baseguides selection of therapeutic agents.

Clinical-Genetic Associations in the Prospective Huntington at Risk Observational Study (PHAROS): Implications for Clinical Trials.

Importance: Identifying measures that are associated with the cytosine-adenine-guanine (CAG) expansion in individuals before diagnosis of Huntington disease (HD) has implications for designing clinical trials.

Objective: To identify the earliest features associated with the motor diagnosis of HD in the Prospective Huntington at Risk Observational Study (PHAROS).

Design, Setting, And Participants: A prospective, multicenter, longitudinal cohort study was conducted at 43 US and Canadian Huntington Study Group research sites from July 9, 1999, through December 17, 2009.

Abnormal lipopolysaccharide binding protein as marker of gastrointestinal inflammation in Parkinson disease.

Objective: An inflammation-driven model of PD has been proposed based on the endotoxin lipopolysaccaride (LPS), a potential source of inflammation in the gastrointestinal system linked to neurotoxicity. Systemic exposure to bacterial endotoxin (LPS) can be determined by measuring plasma LPS binding protein (LBP). We aimed to evaluate whether lipopolysaccharide binding protein (LBP) can be used to distinguish PD subjects from control subjects and to assess whether LBP levels correlate with PD disease severity.

Therapeutic advances in Huntington's Disease.

Huntington's disease is a rare hereditary degenerative disease with a wide variety of symptoms that encompass movement, cognition, and behavior. The genetic mutation that causes the disease has been known for more than 20 y, and animal models have illuminated a host of intracellular derangements that occur downstream of protein translation. A number of clinical trials targeting these metabolic consequences have failed to produce a single effective therapy, although clinical trials continue.

Colonic bacterial composition in Parkinson's disease.

Introduction: We showed that Parkinson's disease (PD) patients have alpha-synuclein (α-Syn) aggregation in their colon with evidence of colonic inflammation. If PD patients have altered colonic microbiota, dysbiosis might be the mechanism of neuroinflammation that leads to α-Syn misfolding and PD pathology.

Methods: Sixty-six sigmoid mucosal biopsies and 65 fecal samples were collected from 38 PD patients and 34 healthy controls.

Effect of creatine monohydrate on clinical progression in patients with Parkinson disease: a randomized clinical trial.

Importance: There are no treatments available to slow or prevent the progression of Parkinson disease, despite its global prevalence and significant health care burden. The National Institute of Neurological Disorders and Stroke Exploratory Trials in Parkinson Disease program was established to promote discovery of potential therapies.

Objective: To determine whether creatine monohydrate was more effective than placebo in slowing long-term clinical decline in participants with Parkinson disease.

Progression of intestinal permeability changes and alpha-synuclein expression in a mouse model of Parkinson's disease.

Parkinson's disease (PD) is a multifocal degenerative disorder for which there is no cure. The majority of cases are sporadic with unknown etiology. Recent data indicate that untreated patients with de novo PD have increased colonic permeability and that both de novo and premotor patients have pathological expression of α-synuclein (α-syn) in their colon.

Gut feelings about smoking and coffee in Parkinson's disease.

Strong epidemiologic evidence suggests that smokers and coffee drinkers have a lower risk of Parkinson's disease (PD). The explanation for this finding is still unknown, and the discussion has focused on two main hypotheses. The first suggests that PD patients have premorbid personality traits associated with dislike for coffee-drinking and smoking.

Diffusion tensor imaging of Parkinson's disease, atypical parkinsonism, and essential tremor.

Diffusion tensor imaging could be useful in characterizing movement disorders because it noninvasively examines multiple brain regions simultaneously. We report a multitarget imaging approach focused on the basal ganglia and cerebellum in Parkinson's disease, parkinsonian variant of multiple system atrophy, progressive supranuclear palsy, and essential tremor and in healthy controls. Seventy-two subjects were studied with a diffusion tensor imaging protocol at 3 Tesla.

Force control deficits in individuals with Parkinson's disease, multiple systems atrophy, and progressive supranuclear palsy.

Objective: This study examined grip force and cognition in Parkinson's disease (PD), Parkinsonian variant of multiple system atrophy (MSAp), progressive supranuclear palsy (PSP), and healthy controls. PD is characterized by a slower rate of force increase and decrease and the production of abnormally large grip forces. Early-stage PD has difficulty with the rapid contraction and relaxation of hand muscles required for precision gripping.

Is alpha-synuclein in the colon a biomarker for premotor Parkinson's disease? Evidence from 3 cases.

Background: Despite clinicopathological evidence that Parkinson's disease (PD) may begin in peripheral tissues, identification of premotor Parkinson's disease is not yet possible. Alpha-synuclein aggregation underlies Parkinson's disease pathology, and its presence in peripheral tissues may be a reliable disease biomarker.

Objective: We sought evidence of alpha-synuclein pathology in colonic tissues before the development of characteristic Parkinson's disease motor symptoms.