2024 Research
271st ENMC international workshop: Towards a unifying effort to fight Kennedy's disease. 20-22 October 2023, Hoofddorp, Netherlands
The workshop held in the Netherlands from October 20–22, 2023, united 27 scientists from academia, healthcare, and industry representing 11 countries, alongside four patient and charity representatives. Focused on Kennedy's Disease (KD), also known as spinal and bulbar muscular atrophy (SBMA), the workshop aimed to consolidate knowledge, align on clinical trial designs, and promote participative medicine for effective treatments. Discussions emphasized KD's molecular mechanisms, highlighting its status as a neuromuscular disorder with motor neuron degeneration. Strategies for therapeutic intervention, including AR activity modulation and targeting post-translational modifications, were proposed. The need for diagnostic, prognostic, and target engagement biomarkers was stressed. Challenges in patient stratification and clinical trial recruitment were acknowledged, with the International KD/SBMA Registry praised for its role. The workshop concluded with a patient-focused session, underscoring challenges in KD diagnosis and the vital support provided by patient associations. To read the article, click here.
Patient-Reported Impact of Symptoms in Spinal and Bulbar Muscular Atrophy
Abstract
Background and objectives: The aim of this study was to determine the frequency and relative importance of symptoms experienced by patients with spinal and bulbar muscular atrophy (SBMA).
Methods:
We conducted a cross-sectional study of 232 participants with SBMA. Participants provided input regarding 18 themes and 208 symptoms that affect patients with SBMA. Participants were asked about the relative importance of each symptom, and analysis was conducted to determine how age, education, disease duration, CAG repeat length, and ambulation status relate to symptom prevalence.
Results:
Hip, thigh, or knee weakness (96.5%), fatigue (96.5%), problems with hands and fingers (95.7%), and limitations with walking (95.7%) were the themes with the highest prevalence in the study population. Ambulatory status was associated with the prevalence of 9 of the 14 themes, and CAG repeat length and education were each associated with 4 of 14 themes. The prevalence of fatigue was reduced in those with a lower CAG repeat length and increased with a longer disease duration. Younger patients reported a higher prevalence of emotional issues.
Discussion:
There are a diversity of themes that are important to patients with SBMA. These themes have a variable level of importance to the population with SBMA and represent clinically meaningful outcome measures for future therapeutic interventions.
Written work prepared by employees of the Federal Government as part of their official duties is, under the U.S. Copyright Act, a “work of the United States Government” for which copyright protection under Title 17 of the United States Code is not available. As such, copyright does not extend to the contributions of employees of the Federal Government.. To read the paper, click here.
Precise editing of pathogenic nucleotide repeat expansions in iPSCs using paired prime editor
Abstract
Nucleotide repeat expansion disorders, a group of genetic diseases characterized by the expansion of specific DNA sequences, pose significant challenges to treatment and therapy development. Here, we present a precise and programmable method called prime editor–mediated correction of nucleotide repeat expansion (PE-CORE) for correcting pathogenic nucleotide repeat expansion. PE-CORE leverages a prime editor and paired pegRNAs to achieve targeted correction of repeat sequences. We demonstrate the effectiveness of PE-CORE in HEK293T cells and patient-derived induced pluripotent stem cells (iPSCs). Specifically, we focus on spinal and bulbar muscular atrophy and spinocerebellar ataxia type, two diseases associated with nucleotide repeat expansion. Our results demonstrate the successful correction of pathogenic expansions in iPSCs and subsequent differentiation into motor neurons. Specifically, we detect distinct downshifts in the size of both the mRNA and protein, confirming the functional correction of the iPSC-derived motor neurons. These findings highlight PE-CORE as a precision tool for addressing the intricate challenges of nucleotide repeat expansion disorders, paving the way for targeted therapies and potential clinical applications., to read the research article published in Oxford University Press, click here.
Blocking the dimerization of polyglutamine-expanded androgen receptor protects cells from DHT-induced toxicity by increasing AR turnover
Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular degenerative disease caused by a polyglutamine expansion in the androgen receptor (AR). This mutation causes AR to misfold and aggregate, contributing to toxicity in and degeneration of motor neurons and skeletal muscle. There is currently no effective treatment or cure for this disease. The role of an interdomain interaction between the amino- and carboxyl-termini of AR, termed the N/C interaction, has been previously identified as a component of androgen receptor-induced toxicity in cell and mouse models of SBMA. However, the mechanism by which this interaction contributes to disease pathology is unclear. This work seeks to investigate this mechanism by interrogating the role of AR homodimerization - a unique form of the N/C-interaction- in SBMA. We show that, although the AR N/C-interaction is reduced by polyglutamine-expansion, homodimers of 5α-dihydrotestosterone (DHT)-bound AR are increased. Additionally, blocking homodimerization results in decreased AR aggregation and toxicity in cell models. Blocking homodimerization results in the increased degradation of AR, which likely plays a role in the protective effects of this mutation. Overall, this work identifies a novel mechanism in SBMA pathology that may represent a novel target for the development of therapeutics for this disease. To access the article published in the "Journal of Biological Chemistry", click here.
