ABSTRACT
The European Spinocerebellar Ataxia Type 3/Machado-Joseph Disease Initiative (ESMI) is a consortium established with the ambition to set up the largest European longitudinal trial-ready cohort of Spinocerebellar Ataxia Type 3/Machado-Joseph Disease (SCA3/MJD), the most common autosomal dominantly inherited ataxia worldwide. A major focus of ESMI has been the identification of SCA3/MJD biomarkers to enable future interventional studies. As biosample collection and processing variables significantly impact the outcomes of biomarkers studies, biosampling procedures standardisation was done previously to study visit initiation. Here, we describe the ESMI consensus biosampling protocol, developed within the scope of ESMI, that ultimately might be translated to other neurodegenerative disorders, particularly ataxias, being the first step to protocol harmonisation in the field.
Subject(s)
Cerebellar Ataxia , Machado-Joseph Disease , Spinocerebellar Ataxias , Spinocerebellar Degenerations , Humans , BiomarkersABSTRACT
Evidence from patients with Parkinson's disease (PD) and our previously reported α-synuclein (SNCA) transgenic rat model support the idea that increased SNCA protein is a substantial risk factor of PD pathogenesis. However, little is known about the transcription control of the human SNCA gene in the brain in vivo. Here, we identified that the DYT6 gene product THAP1 (THAP domain-containing apoptosis-associated protein 1) and its interaction partner CTCF (CCCTC-binding factor) act as transcription regulators of SNCA. THAP1 controls SNCA intronic enhancers' activities, while CTCF regulates its enhancer-promoter loop formation. The SNCA intronic enhancers present neurodevelopment-dependent activities and form enhancer clusters similar to "super-enhancers" in the brain, in which the PD-associated single-nucleotide polymorphisms are enriched. Deletion of the SNCA intronic enhancer clusters prevents the release of paused RNA polymerase II from its promoter and subsequently reduces its expression drastically in the brain, which may provide new therapeutic approaches to prevent its accumulation and thus related neurodegenerative diseases defined as synucleinopathies.
Subject(s)
Brain , Parkinson Disease , Humans , alpha-Synuclein/genetics , Apoptosis Regulatory Proteins/metabolism , Brain/metabolism , DNA-Binding Proteins/metabolism , Introns/genetics , Parkinson Disease/metabolism , Polymorphism, Single Nucleotide , Regulatory Sequences, Nucleic AcidABSTRACT
A skin biopsy of a patient with spinocerebellar ataxia type 3 (SCA3, also known as Machado-Joseph disease (MJD)) caused by a CAG trinucleotide repeat expansion in the ATXN3 gene, was used to generate an induced pluripotent stem cell line, HIHCNi002-A (iPSC-SCA3). Skin fibroblasts were reprogrammed using episomal plasmids carrying hOCT4, hSOX2, hKLF4, hL-MYC, and hLIN28. The iPSC-SCA3 line exhibits chromosomal stability with conservation of the ATXN3 repeat expansion, expresses pluripotency markers and differentiates into endo-, meso-, and ectodermal cells in vitro.
