Machado-Joseph disease, also known as spinocerebellar ataxia type 3, is the most common of the dominantly inherited ataxias worldwide and is characterized by mutant ataxin-3 misfolding, intracellular accumulation of aggregates and neuronal degeneration. Here we investigated the implication of autophagy, the major pathway for organelle and protein turnover, in the accumulation of mutant ataxin-3 aggregates and neurodegeneration found in Machado-Joseph disease and we assessed whether specific stimulation of this pathway could mitigate the disease. Using tissue from patients with Machado-Joseph disease, transgenic mice and a lentiviral-based rat model, we found an abnormal expression of endogenous autophagic markers, accumulation of autophagosomes and decreased levels of beclin-1, a crucial protein in the early nucleation step of autophagy. Lentiviral vector-mediated overexpression of beclin-1 led to stimulation of autophagic flux, mutant ataxin-3 clearance and overall neuroprotective effects in neuronal cultures and in a lentiviral-based rat model of Machado-Joseph disease. These data demonstrate that autophagy is a key degradation pathway, with beclin-1 playing a significant role in alleviating Machado-Joseph disease pathogenesis.
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http://dx.doi.org/10.1093/brain/awr047 | DOI Listing |
Cerebellum
January 2025
Department of Neurology, Fujian Key Laboratory of Molecular Neurology, Fujian Institute of Neurology, The First Affiliated Hospital, Fujian Medical University, Key Laboratory of Brain Aging and Neurodegenerative Diseases of Fujian Medical University, 20 Chazhong Road, Fuzhou, 350005, China.
Peripheral neuropathy (PN) identified as a significant contributor to disability in Spinocerebellar ataxia type 3 (SCA3) patients. This study seeks to assess the utility of current perception threshold (CPT) measurements in evaluating PN in individuals with SCA3 and aims to identify factors influencing CPT values in SCA3 and ascertain whether these values correlate with the severity of ataxia. Ninety-four patients diagnosed with SCA3 and 44 healthy controls were recruited for this investigation.
View Article and Find Full Text PDFOrphanet J Rare Dis
January 2025
Department of Neurology of First Affiliated Hospital, Fujian Medical University, Fuzhou, 350005, China.
Background: Spinocerebellar ataxia type 3 (SCA3) is a hereditary disease caused by abnormally expanded CAG repeats in the ATXN3 gene. The study aimed to identify potential biomarkers for assessing therapeutic efficacy by investigating the associations between expanded CAG repeat size, brain and spinal cord volume loss, and motor functions in patients with SCA3.
Methods: In this prospective, cross-observational study, we analyzed 3D T1-weighted MRIs from 92 patients with SCA3 and 42 healthy controls using voxel-based morphometry and region of interest approaches.
Mov Disord Clin Pract
January 2025
Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Background: Machado-Joseph disease (SCA3/MJD) is a neurodegenerative condition caused by a dominant expansion of a CAG repeat (CAGexp). Most of the variability in the age at onset of symptoms (AO) remains unexplained, and environmental influences were scarcely studied.
Objective: The objective was to test if AO of SCA3/MJD carriers can be associated with markers of the rural environment, such as demographic density (DeD), proportion of rural population (PRP), and the consumption of untreated well water (CWW).
Eur J Neurol
January 2025
School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.
Background: The regulatory role of the apolipoprotein E (APOE) ε4 allele in the clinical manifestations of spinocerebellar ataxia type 3 (SCA3) remains unclear. This study aimed to evaluate the impact of the APOE ε4 allele on cognitive and motor functions in SCA3 patients.
Methods: This study included 281 unrelated SCA3 patients and 182 controls.
CNS Neurosci Ther
December 2024
7T Magnetic Resonance Imaging Translational Medical Center, Department of Radiology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.
Aims: The aim of this study was to investigate the whole-brain asymmetry changes in spinocerebellar ataxia type 3 (SCA3) and their association with movement disorders.
Methods: Voxel-based morphometry (VBM) was used to assess asymmetry in gray matter (GM) volume in 83 genetically confirmed SCA3 patients and 83 sex- and age-matched healthy controls (HCs). The asymmetry index (AI) was analyzed for partial correlation with disease severity, as measured by the Scale for Assessment and Rating of Ataxia (SARA) and International Cooperative Ataxia Rating Scale (ICARS).
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