RESUMEN
BACKGROUND: Helicase for meiosis 1 (HFM1), a putative DNA helicase expressed in germ-line cells, has been reported to be closely associated with premature ovarian insufficiency (POI). However, the underlying molecular mechanism has not been clearly elucidated. The aim of this study was to investigate the function of HFM1 in the first meiotic prophase of mouse oocytes. RESULTS: The results suggested that the deficiency of HFM1 resulting in increased apoptosis and depletion of oocytes in mice, while the oocytes were arrested in the pachytene stage of the first meiotic prophase. In addition, impaired DNA double-strand break repair and disrupted synapsis were observed in the absence of HFM1. Further investigation revealed that knockout of HFM1 promoted ubiquitination and degradation of FUS protein mediated by FBXW11. Additionally, the depletion of HFM1 altered the intranuclear localization of FUS and regulated meiotic- and oocyte development-related genes in oocytes by modulating the expression of BRCA1. CONCLUSIONS: These findings elaborated that the critical role of HFM1 in orchestrating the regulation of DNA double-strand break repair and synapsis to ensure meiosis procession and primordial follicle formation. This study provided insights into the pathogenesis of POI and highlighted the importance of HFM1 in maintaining proper meiotic function in mouse oocytes.
Asunto(s)
Profase Meiótica I , Oocitos , Ubiquitinación , Animales , Femenino , Ratones , Apoptosis/fisiología , Roturas del ADN de Doble Cadena , Reparación del ADN/fisiología , Meiosis/fisiología , Profase Meiótica I/fisiología , Ratones Noqueados , Oocitos/metabolismo , Proteína FUS de Unión a ARN/metabolismo , Proteína FUS de Unión a ARN/genéticaRESUMEN
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that mainly affects the motor system. It is a very heterogeneous disorder, so far more than 40 genes have been described as responsible for ALS. The cause of motor neuron degeneration is not yet fully understood, but there is consensus in the literature that it is the result of a complex interplay of several pathogenic processes, which include alterations in nucleocytoplasmic transport, defects in transcription and splicing, altered formation and/or disassembly of stress granules and impaired proteostasis. These defects result in protein aggregation, impaired DNA repair, mitochondrial dysfunction and oxidative stress, neuroinflammation, impaired axonal transport, impaired vesicular transport, excitotoxicity, as well as impaired calcium influx. We argue here that all the above functions ultimately lead to defects in protein synthesis. Fused in Sarcoma (FUS) is one of the genes associated with ALS. It causes ALS type 6 when mutated and is found mislocalized to the cytoplasm in the motor neurons of sporadic ALS patients (without FUS mutations). In addition, FUS plays a role in all cellular functions that are impaired in degenerating motor neurons. Moreover, ALS patients with FUS mutations present the first symptoms significantly earlier than in other forms of the disease. Therefore, the aim of this review is to further discuss ALS6, detail the cellular functions of FUS, and suggest that the localization of FUS, as well as protein synthesis rates, could be hallmarks of the ALS phenotype and thus good therapeutic targets.
Asunto(s)
Esclerosis Amiotrófica Lateral , Enfermedades Neurodegenerativas , Humanos , Esclerosis Amiotrófica Lateral/patología , Neuronas Motoras/patología , Mutación , Citoplasma/genética , Citoplasma/metabolismo , Citoplasma/patología , Proteína FUS de Unión a ARN/genética , Proteína FUS de Unión a ARN/metabolismoRESUMEN
Amyotrophic lateral sclerosis (ALS) is the most frequent adult-onset motor neuron disorder. The disease is characterized by degeneration of upper and lower motor neurons, leading to death usually within five years after the onset of symptoms. While most cases are sporadic, 5%-10% of cases can be associated with familial inheritance, including ALS type 6, which is associated with mutations in the Fused in Sarcoma (FUS) gene. This work aimed to evaluate how the most frequent ALS-related mutations in FUS, R521C, R521H, and P525L affect the protein structure and function. We used prediction algorithms to analyze the effects of the non-synonymous single nucleotide polymorphisms and performed evolutionary conservation analysis, protein frustration analysis, and molecular dynamics simulations. Most of the prediction algorithms classified the three mutations as deleterious. All three mutations were predicted to reduce protein stability, especially the mutation R521C, which was also predicted to increase chaperone binding tendency. The protein frustration analysis showed an increase in frustration in the interactions involving the mutated residue 521C. Evolutionary conservation analysis showed that residues 521 and 525 of human FUS are highly conserved sites. The molecular dynamics results indicate that protein stability could be compromised in all three mutations. They also affected the exposed surface area and protein compactness. The analyzed mutations also displayed high flexibility in most residues in all variants, most notably in the interaction site with the nuclear import protein of FUS.
Asunto(s)
Esclerosis Amiotrófica Lateral/genética , Simulación por Computador , Mutación , Proteína FUS de Unión a ARN/genética , Esclerosis Amiotrófica Lateral/mortalidad , Análisis Mutacional de ADN , Bases de Datos de Proteínas , Simulación de Dinámica Molecular , Polimorfismo de Nucleótido Simple , Proteína FUS de Unión a ARN/metabolismoRESUMEN
Amyotrophic Lateral Sclerosis (ALS) is one of the most common adult-onset motor neuron disease causing a progressive, rapid and irreversible degeneration of motor neurons in the cortex, brain stem and spinal cord. No effective treatment is available and cell therapy clinical trials are currently being tested in ALS affected patients. It is well known that in ALS patients, approximately 50% of pericytes from the spinal cord barrier are lost. In the central nervous system, pericytes act in the formation and maintenance of the blood-brain barrier, a natural defense that slows the progression of symptoms in neurodegenerative diseases. Here we evaluated, for the first time, the therapeutic effect of human pericytes in vivo in SOD1 mice and in vitro in motor neurons and other neuronal cells derived from one ALS patient. Pericytes and mesenchymal stromal cells (MSCs) were derived from the same adipose tissue sample and were administered to SOD1 mice intraperitoneally. The effect of the two treatments was compared. Treatment with pericytes extended significantly animals survival in SOD1 males, but not in females that usually have a milder phenotype with higher survival rates. No significant differences were observed in the survival of mice treated with MSCs. Gene expression analysis in brain and spinal cord of end-stage animals showed that treatment with pericytes can stimulate the host antioxidant system. Additionally, pericytes induced the expression of SOD1 and CAT in motor neurons and other neuronal cells derived from one ALS patient carrying a mutation in FUS. Overall, treatment with pericytes was more effective than treatment with MSCs. Our results encourage further investigations and suggest that pericytes may be a good option for ALS treatment in the future. Graphical Abstract á .
Asunto(s)
Esclerosis Amiotrófica Lateral/terapia , Células Madre Pluripotentes Inducidas/patología , Neuronas Motoras/patología , Pericitos/trasplante , Superóxido Dismutasa-1/genética , Tejido Adiposo/citología , Tejido Adiposo/metabolismo , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/mortalidad , Esclerosis Amiotrófica Lateral/patología , Animales , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/patología , Tronco Encefálico/metabolismo , Tronco Encefálico/patología , Catalasa/genética , Catalasa/metabolismo , Corteza Cerebral/metabolismo , Corteza Cerebral/patología , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Masculino , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Transgénicos , Neuronas Motoras/metabolismo , Mutación , Pericitos/citología , Pericitos/metabolismo , Proteína FUS de Unión a ARN/genética , Proteína FUS de Unión a ARN/metabolismo , Médula Espinal/metabolismo , Médula Espinal/patología , Superóxido Dismutasa-1/deficiencia , Análisis de SupervivenciaRESUMEN
OBJECTIVE: The aim of this study was to detect the chromosomal translocation t(12;16)(q13;p11) that leads to a gene fusion encoding a FUS-CHOP chimeric protein and has been shown to be highly characteristic of myxoid and round cell subtypes of liposarcoma, in a case of oral myxoid liposarcoma. METHOD AND MATERIALS: Nested reverse transcriptase-polymerase chain reaction to detect the TLS/FUS-CHOP fusion gene transcript was performed. A case of inflammatory fibrous hyperplasia and a case of oral lipoma were included as negative controls. RESULTS: Only the myxoid oral liposarcoma showed a 103-base pair product, specific of TLS/FUS-CHOP fusion type II transcript. CONCLUSION: The identification of FUS-CHOP transcript is potentially useful in the diagnosis and research of oral liposarcomas.