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1.
J Biol Chem ; 300(5): 107246, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38556081

RESUMEN

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.


Asunto(s)
Dihidrotestosterona , Péptidos , Multimerización de Proteína , Receptores Androgénicos , Animales , Humanos , Ratones , Atrofia Bulboespinal Ligada al X/metabolismo , Atrofia Bulboespinal Ligada al X/genética , Atrofia Bulboespinal Ligada al X/patología , Dihidrotestosterona/farmacología , Dihidrotestosterona/metabolismo , Péptidos/metabolismo , Péptidos/genética , Receptores Androgénicos/metabolismo , Receptores Androgénicos/genética , Ratas , Línea Celular
2.
J Neurosci Res ; 102(1): e25278, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38284836

RESUMEN

Spinal and bulbar muscular atrophy (SBMA) is an X-linked disorder that affects males who inherit the androgen receptor (AR) gene with an abnormal CAG triplet repeat expansion. The resulting protein contains an elongated polyglutamine (polyQ) tract and causes motor neuron degeneration in an androgen-dependent manner. The precise molecular sequelae of SBMA are unclear. To assist with its investigation and the identification of therapeutic options, we report here a new model of SBMA in Drosophila melanogaster. We generated transgenic flies that express the full-length, human AR with a wild-type or pathogenic polyQ repeat. Each transgene is inserted into the same safe harbor site on the third chromosome of the fly as a single copy and in the same orientation. Expression of pathogenic AR, but not of its wild-type variant, in neurons or muscles leads to consistent, progressive defects in longevity and motility that are concomitant with polyQ-expanded AR protein aggregation and reduced complexity in neuromuscular junctions. Additional assays show adult fly eye abnormalities associated with the pathogenic AR species. The detrimental effects of pathogenic AR are accentuated by feeding flies the androgen, dihydrotestosterone. This new, robust SBMA model can be a valuable tool toward future investigations of this incurable disease.


Asunto(s)
Atrofia Bulboespinal Ligada al X , Drosophila , Adulto , Humanos , Masculino , Animales , Drosophila melanogaster , Andrógenos , Atrofia Bulboespinal Ligada al X/genética , Atrofia Muscular
3.
Brain ; 146(3): 1083-1092, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35639850

RESUMEN

Spinal and bulbar muscular atrophy, namely Kennedy disease, is a rare progressive neurodegenerative disorder caused by the expansion of a CAG repeat in the first exon of the androgen receptor gene on the X chromosome. We assessed the clinical history, laboratory findings, functional scales and electrophysiological data, as well as the levels of luteinizing hormone, follicle-stimulating hormone and testosterone, in 157 Korean patients with genetically confirmed spinal and bulbar muscular atrophy (mean age at data collection = 56.9 years; range = 33-83 years). Hand tremor was the first symptom noticed by patients at a median age of 35 years, followed by gynaecomastia, orofacial fasciculation, cramps and fatigability in ascending order. Clinical symptoms such as paraesthesia and dysphagia appeared during the later stages of the disease. Cane use during ambulation began at a median age of 62 years. There were statistically significant differences between patients and controls in the results of sensory nerve studies, motor conduction velocity, and distal latencies. Furthermore, among the hormone markers analysed, the level of luteinizing hormone exhibited a negative correlation with the spinal and bulbar muscular atrophy functional rating scale, Korean version. However, among the patients with a disease duration of ≤5 years, the levels of luteinizing hormone showed a significant correlation with assessments using the amyotrophic lateral sclerosis functional rating scale-revised, spinal and bulbar muscular atrophy functional rating scale, Korean version and the 6-minute walk test. In conclusion, our findings provide clinical information from a substantial number of patients with spinal and bulbar muscular atrophy in Korea that accorded with that of patients with this disease worldwide but with updated clinical features.


Asunto(s)
Atrofia Bulboespinal Ligada al X , Atrofia Muscular Espinal , Humanos , Adulto , Persona de Mediana Edad , Atrofia Bulboespinal Ligada al X/diagnóstico , Atrofia Bulboespinal Ligada al X/genética , Estudios Transversales , Temblor , Atrofia Muscular , Hormona Luteinizante , Atrofia Muscular Espinal/genética , Receptores Androgénicos/genética
4.
Cell Mol Biol (Noisy-le-grand) ; 70(9): 74-80, 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39380278

RESUMEN

This study explores a novel therapeutic approach for spinal bulbar muscular atrophy (SBMA), a neurodegenerative disorder caused by a mutation in the Androgen Receptor (AR) gene. The aim is to investigate the potential of CRISPR-Cas9 technology in targeting the mutant AR gene to inhibit its production. The objectives include assessing the accuracy and efficacy of CRISPR-Cas9 guided RNAs in silencing the mutant gene and evaluating the feasibility of this approach as a treatment for SBMA. Computational and in-silico approaches are used to evaluate the feasibility of using CRISPR-Cas9 technology for treating SBMA. Computational analysis is used to design CRISPR-Cas9 guided RNAs targeting the mutant AR gene, assessing their on-target and off-target scores, GC content, and structural accuracy. In-silico simulations predict the potential therapeutic outcomes of the CRISPR-Cas9 approach in an artificial environment. Three guided RNA (gRNA) sequences were designed using the CHOPCHOP tool, targeting specific regions of the AR gene with high efficiency and 100% match. These gRNAs demonstrated effective targeting with minimal off-target scores and optimal GC content. Additionally, lentiCRISPR v2 plasmids were designed for the delivery of CRISPR materials, enabling high-efficiency multiplex genome editing of the AR gene. Thermodynamic ensemble predictions indicated favorable secondary structure stability of the designed gRNAs, further supporting their suitability for gene editing. The evaluation of designed gRNAs confirmed their strong binding ability to the target sequences, validating their potential as effective tools for genome editing. The study highlights the potential of CRISPR-Cas9 technology for targeting the Androgen Receptor gene associated with spinal bulbar muscular atrophy (SBMA). The findings support the feasibility of this approach for gene editing and suggest further exploration in preclinical and clinical settings. Recommendations include continued research to optimize CRISPR-Cas9 delivery methods and enhance specificity for therapeutic applications in SBMA.


Asunto(s)
Sistemas CRISPR-Cas , ARN Guía de Sistemas CRISPR-Cas , Receptores Androgénicos , Sistemas CRISPR-Cas/genética , Humanos , ARN Guía de Sistemas CRISPR-Cas/genética , Receptores Androgénicos/genética , Silenciador del Gen , Atrofia Bulboespinal Ligada al X/genética , Atrofia Bulboespinal Ligada al X/terapia , Simulación por Computador , Mutación/genética , Secuencia de Bases , Edición Génica/métodos
5.
Pract Neurol ; 24(4): 302-305, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-38485225

RESUMEN

A 57-year-old man developed worsening early morning headaches, muscle cramps and falls over 12 months. He had widespread fasciculation and was diagnosed with motor neurone disease, and treated with nocturnal hypoventilation. Based on this diagnosis, he made significant personal and financial decisions including retiring and selling his house. He subsequently developed a lump in his right breast and was found to have gynaecomastia. This triggered genetic testing for Kennedy's disease leading to the correct diagnosis. This case highlights an unusual presentation of a rare disease leading to misdiagnosis and major repercussions for the patient. Recent genetic analysis from the 100 000 genome project suggests Kennedy's disease may be four times more prevalent in the population than previously thought, highlighting the need to consider genetic testing, especially if there is a suggestion of multisystem disease.


Asunto(s)
Atrofia Bulboespinal Ligada al X , Humanos , Masculino , Persona de Mediana Edad , Atrofia Bulboespinal Ligada al X/genética , Atrofia Bulboespinal Ligada al X/diagnóstico
6.
J Hum Genet ; 67(7): 441-444, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35165376

RESUMEN

Mutations in the DNAJB6 gene cause limb girdle muscular dystrophy D1 (LGMD D1) and distal myopathy with rimmed vacuoles. With the discovery of new mutations, the phenotypic spectrum of DNAJB6-related myopathy has been extended, making the diagnosis more complicated. In this study, we describe a female carrier of spinal and bulbar muscular atrophy (SBMA) diagnosed with DNAJB6-related distal myopathy. The c.292_294delGAT (p. Asp98del) mutation in the DNAJB6 gene and a 49 CAG repeat expansion in the androgen receptor (AR) gene were identified. According to the clinical manifestations of distal-dominant lower limb involvement, a myogenic pattern in the electrophysiological study, and rimmed vacuoles on muscle pathology, the patient was ultimately diagnosed with DNAJB6-related distal myopathy. A functional study in a zebrafish model indicated that the c.292_294delGAT (p. Asp98del) mutation contributed to muscle structure defects. This study offers useful insights for the differential diagnosis of a condition in which patients carry pathogenic variants in different genes.


Asunto(s)
Atrofia Bulboespinal Ligada al X , Miopatías Distales , Proteínas del Choque Térmico HSP40 , Chaperonas Moleculares , Distrofia Muscular de Cinturas , Proteínas del Tejido Nervioso , Animales , Atrofia Bulboespinal Ligada al X/diagnóstico , Atrofia Bulboespinal Ligada al X/genética , Miopatías Distales/diagnóstico , Miopatías Distales/genética , Femenino , Proteínas del Choque Térmico HSP40/genética , Humanos , Chaperonas Moleculares/genética , Distrofia Muscular de Cinturas/genética , Proteínas del Tejido Nervioso/genética , Pez Cebra/genética
7.
Eur J Neurol ; 29(12): 3556-3563, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35996994

RESUMEN

BACKGROUND AND PURPOSE: Spinal-bulbar muscular atrophy (SBMA) (Kennedy's disease) is a motor neuron disease. Kennedy's disease is nearly exclusively caused by mutations in the androgen receptor encoding gene (AR). The results of studies aimed at identification of the genetic cause of a disease that best approximates SBMA in a pedigree (four patients) without mutations in AR are reported. METHODS: Clinical investigations included thorough neurological and non-neurological examinations and testing. Genetic analysis was performed by exome sequencing using standard protocols. UBA1 mutations were modeled on the crystal structure of UBA1. RESULTS: The clinical features of the patients are described in detail. A missense mutation in UBA1 (c.T1499C; p.Ile500Thr) was identified as the probable cause of the non-Kennedy SBMA in the pedigree. Like AR, UBA1 is positioned on chromosome X. UBA1 is a highly conserved gene. It encodes ubiquitin-like modifier activating enzyme 1 (UBA1) which is the major E1 enzyme of the ubiquitin-proteasome system. Interestingly, UBA1 mutations can also cause infantile-onset X-linked spinal muscular atrophy (XL-SMA). The mutation identified here and the XL-SMA causative mutations were shown to affect amino acids positioned in the vicinity of UBA1's ATP binding site and to cause structural changes. CONCLUSION: UBA1 was identified as a novel SBMA causative gene. The gene affects protein homeostasis which is one of most important components of the pathology of neurodegeneration. The contribution of this same gene to the etiology of XL-SMA is discussed.


Asunto(s)
Artrogriposis , Atrofia Bulboespinal Ligada al X , Enfermedad de la Neurona Motora , Atrofia Muscular Espinal , Enzimas Activadoras de Ubiquitina , Humanos , Artrogriposis/complicaciones , Atrofia Bulboespinal Ligada al X/genética , Enfermedad de la Neurona Motora/complicaciones , Atrofia Muscular/complicaciones , Atrofia Muscular Espinal/genética , Receptores Androgénicos/genética , Ubiquitinas , Enzimas Activadoras de Ubiquitina/genética
8.
BMC Neurol ; 22(1): 425, 2022 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-36376797

RESUMEN

BACKGROUND: Spinal and bulbar muscular atrophy (SBMA) is an X-linked recessive hereditary neuromuscular disorder caused by the expanded trinucleotide repeat in the androgen receptors gene. The major clinical manifestations of SBMA consist of weakness in the bulbar and limb muscles, fasciculations, tremors, cramps, sensory impairment, and gynecomastia. However, atypical SBMA cases may lead to misdiagnosis. Muscular fatigue and decremental responses to repetitive nerve stimulation (RNS), despite being observed in some SBMA patients, are usually occurred in MG patients, and patient with the symptom of mastication fatigue was rarely reported. In addition, cardiological investigations have been performed in SBMA patients and several ECG alterations were identified. Here we report an SBMA patient presenting with a rare onset symptom of mastication fatigue, who has been detected with a positive titin antibody in the serum and showed a WPW pattern electrocardiogram. CASE PRESENTATION: The patient showed mildly progressive fatigue in the muscles of mastication over 3 years. Neurological examination showed facial muscle weakness and a wasting tongue with fasciculations, but the weakness, wasting, or fasciculations were not obvious in the limbs. 3-Hz RNS showed a decremental response in bilateral orbicularis oculi. The test of titin antibody was positive in the serum, and the electrocardiogram showed a WPW pattern ECG. Genetic analysis revealed an increased number (39 repeats) of tandem CAG repeats in the AR gene, which confirmed the diagnosis of SBMA. The fatigue symptom was significantly improved after oral pyridostigmine bromide treatment. CONCLUSION: This case calls for more attention to muscular fatigue as the onset symptoms of Kennedy's disease. ECG screening is of importance in SBMA patients and further studies are needed to investigate the titin antibody in SBMA patients as well as other neurogenic disorders.


Asunto(s)
Atrofia Bulboespinal Ligada al X , Atrofia Muscular Espinal , Humanos , Masculino , Atrofia Bulboespinal Ligada al X/complicaciones , Atrofia Bulboespinal Ligada al X/diagnóstico , Atrofia Bulboespinal Ligada al X/genética , Conectina/genética , Masticación , Fasciculación , Fatiga
9.
J Med Genet ; 58(6): 385-391, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-32571900

RESUMEN

BACKGROUND: Spinal and bulbar muscular atrophy (SBMA), also known as Kennedy's disease, is an X-linked motor neuron disorder caused by an expanded CAG repeat in the gene coding for the androgen receptor (AR). The range and significance of reduced penetrance alleles in SBMA has not been fully determined to date. We presently sought to determine the range of reduced penetrance alleles in SBMA. METHODS: Through systematic literature review and meta-analysis, we collected and analysed data from 2576 patients with SBMA and compared the distributions of the CAG repeat number (CAG)n in the AR gene between patients and 112 248 control alleles of the general population. RESULTS: Our analysis revealed an unexpectedly high frequency of expanded SBMA-associated alleles, with (CAG)n ≥35 present in 107/100,000 and (CAG)n ≥38 present in 27/100,000 of the general population. Consequently, we suggest an updated model describing the distribution of expanded alleles in the general population. We argue against the established cut-off principle for the penetrance of SBMA and suggest that penetrance gradually increases from 35 to approximately 46 (CAG)n, above which it reaches a plateau approaching maximum value. CONCLUSION: Asymptomatic men of the general population with no/unknown SBMA family history are free of risk when carrying (CAG)n ≤34, are at intermediate but increasing risk for developing SBMA when carrying (CAG)n ≈35-46 and have close to 100% risk of developing the disease when carrying (CAG)n ≥47. The above observations should be helpful and clinically useful when providing genetic counselling to individuals and families bearing SBMA-associated alleles.


Asunto(s)
Atrofia Bulboespinal Ligada al X/genética , Penetrancia , Edad de Inicio , Alelos , Atrofia Bulboespinal Ligada al X/epidemiología , Femenino , Frecuencia de los Genes , Humanos , Meiosis , Modelos Genéticos
10.
Neurol Neurochir Pol ; 56(3): 276-280, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35661131

RESUMEN

INTRODUCTION: The expansion of a hexanucleotide GGGGCC repeat (G4C2) in the C9orf72 locus is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In addition, C9orf72 expansion has also been detected in patients with a clinical manifestation of Parkinson's Disease (PD), Alzheimer's Disease (AD), Huntington's Disease (HD), and ataxic disorders. MATERIAL AND METHODS: A total of 1,387 patients with clinically suspected ALS, HD or spinal and bulbar muscular atrophy (SBMA) were enrolled, and the prevalence of C9orf72 expansions was estimated. RESULTS: The hexanucleotide expansion accounted for 3.7% of the ALS patients, 0.2% of the HD suspected patients with excluded HTT mutation, and 1.3% of the suspected SBMA patients with excluded mutation in AR gene. CONCLUSIONS: This is the first report revealing the presence of C9orf72 expansion in patients with a suspected SBMA diagnosis. Consequently, we advise testing for C9orf72 expansion in patients presenting with the SBMA phenotype and a genetically unsolved diagnosis.


Asunto(s)
Esclerosis Amiotrófica Lateral , Atrofia Bulboespinal Ligada al X , Demencia Frontotemporal , Esclerosis Amiotrófica Lateral/genética , Atrofia Bulboespinal Ligada al X/genética , Proteína C9orf72/genética , Expansión de las Repeticiones de ADN/genética , Demencia Frontotemporal/genética , Humanos , Proteínas/genética
11.
Neurol Sci ; 42(10): 4317-4320, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34085109

RESUMEN

We report a 51-year-old male diagnosed with X-linked recessive spinal and bulbar muscular atrophy (SBMA) by genetic testing who presented with 30 years history of progressive proximal and bulbar weakness responsive to cholinesterase inhibitor. Although the anti-acetylcholine receptor antibody (anti-AChR Ab) was negative, the myasthenic state was confirmed by decremental response in repetitive nerve stimulation and increased jitter frequency and blocking in single fiber-electromyography. While myasthenia gravis and SBMA may co-exist independently in an individual having the signs and symptoms of both conditions, the absence of anti-AChR Ab may imply that myasthenia can be an exaggerated activity-induced fatigue or weakness from the latter.


Asunto(s)
Atrofia Bulboespinal Ligada al X , Miastenia Gravis , Atrofia Bulboespinal Ligada al X/genética , Inhibidores de la Colinesterasa/uso terapéutico , Electromiografía , Humanos , Masculino , Persona de Mediana Edad , Debilidad Muscular/genética , Miastenia Gravis/complicaciones , Miastenia Gravis/tratamiento farmacológico , Miastenia Gravis/genética
12.
Int J Mol Sci ; 22(11)2021 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-34073630

RESUMEN

Motor neuron diseases (MNDs) are neurodegenerative disorders characterized by upper and/or lower MN loss. MNDs include amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), and spinal and bulbar muscular atrophy (SBMA). Despite variability in onset, progression, and genetics, they share a common skeletal muscle involvement, suggesting that it could be a primary site for MND pathogenesis. Due to the key role of muscle-specific microRNAs (myomiRs) in skeletal muscle development, by real-time PCR we investigated the expression of miR-206, miR-133a, miR-133b, and miR-1, and their target genes, in G93A-SOD1 ALS, Δ7SMA, and KI-SBMA mouse muscle during disease progression. Further, we analyzed their expression in serum of SOD1-mutated ALS, SMA, and SBMA patients, to demonstrate myomiR role as noninvasive biomarkers. Our data showed a dysregulation of myomiRs and their targets, in ALS, SMA, and SBMA mice, revealing a common pathogenic feature associated with muscle impairment. A similar myomiR signature was observed in patients' sera. In particular, an up-regulation of miR-206 was identified in both mouse muscle and serum of human patients. Our overall findings highlight the role of myomiRs as promising biomarkers in ALS, SMA, and SBMA. Further investigations are needed to explore the potential of myomiRs as therapeutic targets for MND treatment.


Asunto(s)
Esclerosis Amiotrófica Lateral , Atrofia Bulboespinal Ligada al X , MicroARNs , Mutación Missense , Superóxido Dismutasa-1 , Superóxido Dismutasa , Sustitución de Aminoácidos , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Animales , Atrofia Bulboespinal Ligada al X/genética , Atrofia Bulboespinal Ligada al X/metabolismo , Humanos , Ratones , Ratones Transgénicos , MicroARNs/genética , MicroARNs/metabolismo , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa-1/genética , Superóxido Dismutasa-1/metabolismo
13.
Hum Mol Genet ; 27(14): 2425-2442, 2018 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-29897452

RESUMEN

A distinguishing aspect of spinal and bulbar muscular atrophy (SBMA) is its androgen-dependence, possibly explaining why only males are clinically affected. This disease, which impairs neuromuscular function, is linked to a polyglutamine expansion mutation in the androgen receptor (AR). In mouse models of SBMA, motor dysfunction is associated with pronounced defects in neuromuscular transmission, including defects in evoked transmitter release (quantal content, QC) and fiber membrane excitability (based on the resting membrane potential, RMP). However, whether such defects are androgen-dependent is unknown. Thus, we recorded synaptic potentials intracellularly from adult muscle fibers of transgenic (Tg) AR97Q male mice castrated pre-symptomatically. Although castration largely protects both QC and the RMP of fibers, correlating with the protective effect of castration on motor function, significant deficits in QC and RMP remained. Surprisingly, comparable defects in QC and RMP were also observed in pre-symptomatic AR97Q males, indicating that such defects emerge early and are pre-clinical. Exposing asymptomatic Tg females to androgens also induces both motor dysfunction and comparable defects in QC and RMP. Notably, asymptomatic Tg females also showed significant deficits in QC and RMP, albeit less severe, supporting their pre-clinical nature, but also raising questions about the androgen-dependence of pre-clinical symptoms. In summary, current evidence indicates that disease progression depends on androgens, but early pathogenic events may be triggered by the mutant AR allele independent of androgens. Such early, androgen-independent disease mechanisms may also be relevant to females carrying the SBMA allele.


Asunto(s)
Andrógenos/genética , Atrofia Bulboespinal Ligada al X/fisiopatología , Neuronas Motoras/patología , Receptores Androgénicos/genética , Andrógenos/metabolismo , Animales , Atrofia Bulboespinal Ligada al X/genética , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Ratones , Ratones Transgénicos , Neuronas Motoras/metabolismo , Fibras Musculares Esqueléticas/patología , Músculo Esquelético/metabolismo , Músculo Esquelético/patología
14.
Curr Opin Neurol ; 33(5): 629-634, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32773451

RESUMEN

PURPOSE OF REVIEW: The aim of this study was to illustrate the current understanding and avenues for developing treatment in spinal and bulbar muscular atrophy (SBMA), an inherited neuromuscular disorder caused by a CAG trinucleotide repeat expansion in the androgen receptor (AR) gene. RECENT FINDINGS: Important advances have been made in characterizing the molecular mechanism of the disease, including the disruption of protein homeostasis, intracellular trafficking and signalling pathways. Biomarkers such as MRI quantification of muscle volume and fat fraction have been used to track disease progression, and will be useful in future clinical studies. Therapies tested and under development have been based on diverse strategies, including targeting mutant AR gene expression, stability and activity, and pathways that mitigate disease toxicity. SUMMARY: We provide an overview of the recent advances in understanding the SBMA disease mechanism and highlight efforts to translate these insights into well tolerated and effective therapy.


Asunto(s)
Atrofia Bulboespinal Ligada al X/genética , Receptores Androgénicos/genética , Expansión de Repetición de Trinucleótido , Biomarcadores , Atrofia Bulboespinal Ligada al X/metabolismo , Atrofia Bulboespinal Ligada al X/terapia , Progresión de la Enfermedad , Humanos
16.
Adv Exp Med Biol ; 1195: 199-204, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32468478

RESUMEN

X-linked spinal and bulbar muscular atrophy (SBMA), also known as Kennedy syndrome, is an adult-onset neurodegenerative disorder characterized by slowly progressive muscle atrophy and other severe symptoms gradually leading to reduced mobility and ultimately to death due to respiratory failure. Two decades ago we reported the first prenatal diagnosis of SBMA worldwide. Here we present a Greek family in which we have performed seven prenatal DNA tests for SBMA mutation after extensive genetic counseling. Since there is not yet a cure for SBMA, prenatal testing may be a good choice for couples at risk for prevention of this neurodegenerative disorder in their offspring. The issues addressed during genetic counseling for such a disabling disorder of adult onset are discussed as a paradigm for other conditions with similar characteristics.


Asunto(s)
Atrofia Bulboespinal Ligada al X/diagnóstico , Atrofia Bulboespinal Ligada al X/genética , Salud de la Familia , Asesoramiento Genético , Mutación , Diagnóstico Prenatal , Adulto , Atrofia Bulboespinal Ligada al X/complicaciones , Femenino , Grecia , Humanos , Atrofia Muscular/complicaciones , Embarazo
17.
Neurobiol Dis ; 124: 1-13, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30391288

RESUMEN

Spinal and bulbar muscular atrophy (SBMA) is a neurodegenerative disease caused by the expansion of polyglutamine region in the androgen receptor. To gain insights into mechanisms of SBMA, four wild-type and five SBMA iPSC lines were differentiated to spinal motor neurons (sMNs) with high efficiency. SBMA sMNs showed neurite defects, reduced sMN survival and decreased protein synthesis levels. Microarray analysis revealed a dysregulation in various neuronal-related signalling pathways in SBMA sMNs. Strikingly, FAM135B a novel gene of unknown function, was found drastically downregulated in SBMA sMNs. Knockdown of FAM135B in wild-type sMNs reduced their survival and contributed to neurite defects, similar to SBMA sMNs, suggesting a functional role of FAM135B in SBMA. The degenerative phenotypes and dysregulated genes revealed could be potential therapeutic targets for SBMA.


Asunto(s)
Atrofia Bulboespinal Ligada al X/metabolismo , Atrofia Bulboespinal Ligada al X/patología , Péptidos y Proteínas de Señalización Intracelular/fisiología , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Neuritas/metabolismo , Neuritas/patología , Atrofia Bulboespinal Ligada al X/genética , Diferenciación Celular , Perfilación de la Expresión Génica , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/patología , Péptidos y Proteínas de Señalización Intracelular/genética , Fenotipo , Transducción de Señal
18.
Funct Integr Genomics ; 19(3): 533-539, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30612224

RESUMEN

Kennedy's disease, resulted from the expansion of a CAG repeat in exon 1 of androgen receptor (AR) gene, is a motor neuron degenerative disease in the brainstem and spinal cord with the slow development of facial, bulbar, and limb muscle degeneration. To investigate the clinical manifestations and gene mutations in Han Chinese patients with Kennedy's disease. The clinical manifestations of 5 male Han Chinese patients including 2 probands and their relatives from 2 families and 1 sporadic case were retrospectively studied. The CAG repeats in the first exon of AR were screened in 5 Han Chinese people including 2 probands and their healthy relatives from 2 families and 1 sporadic case by polymerase chain reaction (PCR) and direct sequencing. The average age at onset of Kennedy's disease was 48.20 ± 8.70 (mean ± SD) years and the average duration was 7.60 ± 5.32 years. All the patients showed slow onset and progressive weakness, wasting, and fasciculations of the whole body. Four patients demonstrated decreased fertility and 1 patient showed mild gynecomastia. Serum creatine kinase and testosterone levels were elevated mildly in 2 and 1 patients, respectively. The electromyogram showed neurogenic abnormalities. Muscle magnetic resonance demonstrated reduced muscle volume and fatty infiltration. Three different enlarged CAG domains were discovered in the 2 families and 1 sporadic patient with Kennedy's disease, and the CAG repeat number was 48, 43, and 44, respectively. The clinical manifestations of Kennedy's disease in Han Chinese middle-aged men were progressive weakness and atrophy in the bulbar and spinal muscles, occasionally demonstrating incomplete androgen insensitivity syndrome. These patients were also characterized with enlarged CAG repeat number in the first exon of AR, indicating that CAG number could be used in the diagnosis of Han Chinese patients with Kennedy's disease.


Asunto(s)
Atrofia Bulboespinal Ligada al X/patología , Mutación , Fenotipo , Receptores Androgénicos/genética , Adulto , Atrofia Bulboespinal Ligada al X/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Linaje
19.
Eur J Neurol ; 26(3): 519-524, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30351503

RESUMEN

BACKGROUND AND PURPOSE: Literature data on spinal and bulbar muscular atrophy (SBMA) epidemiology are limited and restricted to specific populations. The aim of our study was to accurately collect information about SBMA patients living in the Veneto region in Italy to compute reliable epidemiological data. Androgen receptor (AR) lineages were genotyped to evaluate the presence of a founder effect. METHODS: A prevalence survey considering all SBMA patients diagnosed in the Italian Veneto region on 31 January 2018 was carried out. The presence of different haplotypes obtained genotyping 15 polymorphic markers (single nucleotide polymorphisms and short tandem repeats) around the AR gene was evaluated. RESULTS: Based on 68 patients, the punctual prevalence of the disease on 31 January 2018 was 2.58/100 000 (95% confidence interval 1.65-3.35) in the male population. Five different haplotypes were identified, confirming the existence of multiple founder effects. It was also observed that, within the same haplotype, patients had a similar CAG repeat number (P-value < 0.001). CONCLUSIONS: A reliable estimation of SBMA prevalence in the Italian Veneto region was calculated which does not seem to be affected by a strong founder effect. Moreover, our data suggest that the length of the CAG expansion could be preserved in patients harbouring the same haplotype.


Asunto(s)
Atrofia Bulboespinal Ligada al X/epidemiología , Atrofia Bulboespinal Ligada al X/genética , Efecto Fundador , Haplotipos , Sistema de Registros , Anciano , Haplotipos/genética , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad
20.
Neurol Sci ; 40(7): 1393-1401, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30915613

RESUMEN

BACKGROUND: Spinal and bulbar muscular atrophy (SBMA) is a late onset, X-linked neuromuscular disease. Bulbar symptoms are a main characteristic of the disease but a tool for their clinical evaluation still does not exist. The aim of this study was to design and test a new scale (6-K-scale) for evaluation of bulbar function in SBMA. METHODS: We considered 60 genetically confirmed SBMA patients and built a scale to evaluate the V, VII, IX, X, and XII cranial nerves (CN) and the ansa cervicalis. Functional status was evaluated through the Spinal and Bulbar Muscular Atrophy Functional Rating Scale (SBMAFRS), 6-min-walk-test (6MWT), Adult Myopathy Assessment Tool (AMAT) scale, and FVC%. Twenty patients underwent a re-test after 3 weeks, while 31 were tested longitudinally after 6 months. Validation of the scale included reliability assessment and factorial analysis. To evaluate convergent validity, correlations between the 6-K-scale and functional parameters were performed. RESULTS: Internal consistency as measured by Cronbach's alpha was high (0.85) as was test-retest reliability. Principal component analysis yielded a six-factor solution accounting for 71.7% of the variance. The scale score was strongly correlated with the functional parameters. CONCLUSION: In conclusion, we designed and validated a new scale for bulbar evaluation in SBMA patients. This scale will be a useful tool in the clinical practice as well as a possible outcome measure in clinical trials.


Asunto(s)
Atrofia Bulboespinal Ligada al X/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Atrofia Bulboespinal Ligada al X/genética , Atrofia Bulboespinal Ligada al X/fisiopatología , Nervios Craneales/fisiopatología , Análisis Factorial , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados
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