Gastric smooth muscle cells manifest an abnormal phenotype in Parkinson ’s disease rats with gastric dysmotility

AbstractGastroparesis is a common symptom in Parkinson ’s disease (PD) and whether any change occurs in gastric smooth muscle cells (SMCs) of PD patients is unclear. We previously reported that rats with bilateral substantia nigra lesions induced by 6-hydroxydopamine (6-OHDA), referred to as 6-OHDA rats, manifest typical gastroparesis. In the present study, we further investigate the underlying mechanism. By means of an organ bath system and an implantable radiotelemetry system, both a weakened contractile force of gastric circular smooth muscle and gastric myoelectric activity were detected in the 6-OHDA rats and phasic and tonic contractions e licited by carbachol or high concentration of potassium were significantly reduced in gastric circular muscle strips. A thickened smooth muscle layer was observed under a light microscope and an ultrastructure of hypertrophic SMCs, with increased caveolae and decreased dense bodies, was observed und er transmission electron microscope. Furthermore, the mRNA and protein expression levels of contractile markers (myosin light chain 20, myosin heavy chain 11 and α-smooth muscle actin) and the transcription factor serum response factor (SRF) were significantly decreased, while the TNFα and IL-1β content was increased in the 6-OHDA rats. These results suggest that the decreased contractile force in 6-OHDA rats may be associated with the phenotypic abnormality observed in SMCs, which is due to downregulated contractile...
Source: Cell and Tissue Research - Category: Cytology Source Type: research

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ConclusionsLoss of Nrf2/BH4/nNOS expression in PD impairs antioxidant gene expression, which deregulates NO synthesis, thereby contributing to the development of GI dysmotility and constipation. Nitric oxide appears to be important to maintain dopamine synthesis in the colon.
Source: Digestive Diseases and Sciences - Category: Gastroenterology Source Type: research
Conclusions Dysautonomic symptoms frequently occuring in α-synucleinopathies comprise cardiovascular, gastrointestinal, urogenital and thermoregulatory disturbances. These symptoms reduce quality of life and worsen prognosis. The understanding of their pathophysiology, as well as the detection of α-synuclein deposition and autonomic dysfunction in the premotor stages of α-synucleinopathies may be key for identifying novel treatment targets and improving clinical outcomes. While causative treatment is not yet available, improvement of quality of life can be achieved by personalized symptomatic treatment r...
Source: Frontiers in Neurology - Category: Neurology Source Type: research
AbstractPurpose of ReviewPatients with Parkinson ’s disease (PD) often display gastrointestinal and genitourinary autonomic symptoms years or even decades prior to diagnosis. These symptoms are thought to be caused in part by pathological α-synuclein inclusions in the peripheral autonomic and enteric nervous systems. It has been proposed that t he initial α-synuclein aggregation may in some PD patients originate in peripheral nerve terminals and then spread centripetally to the spinal cord and brainstem. In vivo imaging methods can directly quantify the degeneration of the autonomic nervous system as well...
Source: Current Neurology and Neuroscience Reports - Category: Neuroscience Source Type: research
Prion-like Propagation of α-synuclein in the gut-brain axis. Brain Res Bull. 2018 Jun 09;: Authors: Chen Y, Shao Q, Yuan YH, Chen NH Abstract Parkinson's disease (PD) is a progressive degenerative disease of the nervous system, which is characterized by movement disorders, such as static tremor, rigidity, and bradykinesia in advanced patients. Gastrointestinal (GI) dysfunction, such as gastric dysmotility, constipation, and anorectic dysfunction, is common non-motor symptom in the early stage of PD. The progression of PD includes the degenerative loss of dopaminergic (DA) neurons and aggregation...
Source: Brain Research Bulletin - Category: Neurology Authors: Tags: Brain Res Bull Source Type: research
Abstract Alpha-Synuclein (α-syn) is by far the most highly vetted pathogenic and therapeutic target in Parkinson's disease. Aggregated α-syn is present in sporadic Parkinson's disease, both in the central nervous system (CNS) and peripheral nervous system (PNS). The enteric division of the PNS is of particular interest because 1) gastric dysfunction is a key clinical manifestation of Parkinson's disease, and 2) Lewy pathology in myenteric and submucosal neurons of the enteric nervous system (ENS) has been referred to as stage zero in the Braak pathological staging of Parkinson's disease. The presence o...
Source: Neurobiology of Disease - Category: Neurology Authors: Tags: Neurobiol Dis Source Type: research
Abstract Helicobacter pylori infection (Hp-I) is a prevalent disorder identified in the majority of the population in many countries around the world and is responsible for substantial gastrointestinal morbidity. Likewise, neurodegenerative diseases such as Alzheimer's disease, Parkinson's diseases, multiple sclerosis or glaucoma defined as ocular Alzheimer's disease, are associated with a large public health burden and are among the leading causes of disability. Emerging evidences suggest that Hp-I may be associated with neurodegenerative conditions. Moreover, Hp-I could be a predictor of metabolic syndrome (MetS...
Source: Current Molecular Medicine - Category: Molecular Biology Authors: Tags: Curr Mol Med Source Type: research
Abstract The synucleinopathies—Parkinson's disease, dementia with Lewy bodies, multiple system atrophy, and pure autonomic failure—result from distinct patterns of abnormal α‐synuclein aggregation throughout the nervous system. Autonomic dysfunction in these disorders results from variable involvement of the central and peripheral autonomic networks. The major pathologic hallmark of Parkinson's disease and dementia with Lewy bodies is Lewy bodies and Lewy neurites; of multiple system atrophy, oligodendroglial cytoplasmic inclusions; and of pure autonomic failure, peripheral neuronal cytoplasmic inclusio...
Source: Movement Disorders - Category: Neurology Authors: Tags: Review Source Type: research
CONCLUSION: Under dopaminergic nigrostriatal denervation, treatment with L-DOPA/BE ameliorated colonic motility through a normalization of myenteric cholinergic neurotransmission, along with an improvement of colonic inflammation. PMID: 28526609 [PubMed - as supplied by publisher]
Source: Neuropharmacology - Category: Drugs & Pharmacology Authors: Tags: Neuropharmacology Source Type: research
Background and Objectives: Gastrointestinal dysfunction is a common non motor symptom in Parkinson's disease (PD). However, the potential association between vitamin D and gastroparesis in PD has not been previously investigated. The aim of this study was to compare vitamin D levels between drug-naive de novo PD patients with normal gastric emptying and those with delayed gastric emptying. Methods: Fifty-one patients with drug-naive de novo PD and 20 age-matched healthy controls were enrolled in this study. Gastric emptying time (GET) was assessed by scintigraphy, and gastric emptying half-time (T1/2) was determined. The P...
Source: Neurodegenerative Diseases - Category: Neurology Source Type: research
Abstract BACKGROUND AND OBJECTIVES: Gastrointestinal dysfunction is a common non motor symptom in Parkinson's disease (PD). However, the potential association between vitamin D and gastroparesis in PD has not been previously investigated. The aim of this study was to compare vitamin D levels between drug-naive de novo PD patients with normal gastric emptying and those with delayed gastric emptying. METHODS: Fifty-one patients with drug-naive de novo PD and 20 age-matched healthy controls were enrolled in this study. Gastric emptying time (GET) was assessed by scintigraphy, and gastric emptying half-time (T1/2...
Source: Neuro-Degenerative Diseases - Category: Neurology Authors: Tags: Neurodegener Dis Source Type: research
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