Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Más filtros

Banco de datos
Tipo de estudio
Tipo del documento
Asunto de la revista
País de afiliación
Intervalo de año de publicación
1.
Brain Commun ; 4(2): fcac081, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35445192

RESUMEN

Amyotrophic lateral sclerosis is a late-onset adult neurodegenerative disease, although there is mounting electrophysiological and pathological evidence from patients and animal models for a protracted preclinical period of motor neuron susceptibility and dysfunction, long before clinical diagnosis. The key molecular mechanisms linked to motor neuron vulnerability in amyotrophic lateral sclerosis have been extensively studied using transcriptional profiling in motor neurons isolated from adult mutant superoxide dismutase 1 mice. However, neonatal and embryonic motor neurons from mutant superoxide dismutase 1 mice show abnormal morphology and hyperexcitability, suggesting preceding transcriptional dysregulation. Here, we used RNA sequencing on motor neurons isolated from embryonic superoxide dismutase 1G93A mice to determine the earliest molecular mechanisms conferring neuronal susceptibility and dysfunction known in a mouse model of amyotrophic lateral sclerosis. Transgenic superoxide dismutase 1G93A mice expressing the spinal motor neuron homeobox HB9:green fluorescent protein reporter allowed unambiguous identification and isolation of motor neurons using fluorescence-activated cell sorting. Gene expression profiling of isolated motor neurons revealed transcriptional dysregulation in superoxide dismutase 1G93A mice as early as embryonic Day 12.5 with the majority of differentially expressed genes involved in RNA processing and α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate-mediated glutamate receptor signalling. We confirmed dysregulation of the α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor Subunit 2, at transcript and protein levels, in embryonic superoxide dismutase 1G93A mouse motor neurons and human motor neurons derived from amyotrophic lateral sclerosis patient induced pluripotent stem cells harbouring pathogenic superoxide dismutase 1 mutations. Mutant superoxide dismutase 1 induced pluripotent stem cell-derived motor neurons showed greater vulnerability to α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate-mediated excitotoxicity, consistent with α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor Subunit 2 downregulation. Thus, α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor Subunit 2 deficiency leading to enhanced α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor signalling, calcium influx, hyperexcitability, and chronic excitotoxicity is a very early and intrinsic property of spinal motor neurons that may trigger amyotrophic lateral sclerosis pathogenesis later in life. This study reinforces the concept of therapeutic targeting of hyperexcitability and excitotoxicity as potential disease-modifying approaches for amyotrophic lateral sclerosis.

3.
Sci Rep ; 9(1): 15928, 2019 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-31685864

RESUMEN

MicroRNAs (miRNAs) are translational regulatory molecules with recognised roles in heart development and disease. Therefore, it is important to define the human miRNA expression profile in cardiac progenitors and early-differentiated cardiomyocytes and to determine whether critical cardiac transcription factors such as NKX2-5 regulate miRNA expression. We used an NKX2-5eGFP/w reporter line to isolate both cardiac committed mesoderm and cardiomyocytes. We identified 11 miRNAs that were differentially expressed in NKX2-5 -expressing cardiac mesoderm compared to non-cardiac mesoderm. Subsequent profiling revealed that the canonical myogenic miRNAs including MIR1-1, MIR133A1 and MIR208A were enriched in cardiomyocytes. Strikingly, deletion of NKX2-5 did not result in gross changes in the cardiac miRNA profile, either at committed mesoderm or cardiomyocyte stages. Thus, in early human cardiomyocyte commitment and differentiation, the cardiac myogenic miRNA program is predominantly regulated independently of the highly conserved NKX2-5 -dependant gene regulatory network.


Asunto(s)
Proteína Homeótica Nkx-2.5/metabolismo , MicroARNs/metabolismo , Miocitos Cardíacos/metabolismo , Diferenciación Celular , Línea Celular , Técnicas de Inactivación de Genes , Redes Reguladoras de Genes , Proteína Homeótica Nkx-2.5/deficiencia , Proteína Homeótica Nkx-2.5/genética , Células Madre Embrionarias Humanas/citología , Células Madre Embrionarias Humanas/metabolismo , Humanos , Mesodermo/metabolismo , MicroARNs/genética , Células Madre/citología , Células Madre/metabolismo , Transcriptoma
4.
Nat Commun ; 9(1): 1373, 2018 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-29636455

RESUMEN

Congenital heart defects can be caused by mutations in genes that guide cardiac lineage formation. Here, we show deletion of NKX2-5, a critical component of the cardiac gene regulatory network, in human embryonic stem cells (hESCs), results in impaired cardiomyogenesis, failure to activate VCAM1 and to downregulate the progenitor marker PDGFRα. Furthermore, NKX2-5 null cardiomyocytes have abnormal physiology, with asynchronous contractions and altered action potentials. Molecular profiling and genetic rescue experiments demonstrate that the bHLH protein HEY2 is a key mediator of NKX2-5 function during human cardiomyogenesis. These findings identify HEY2 as a novel component of the NKX2-5 cardiac transcriptional network, providing tangible evidence that hESC models can decipher the complex pathways that regulate early stage human heart development. These data provide a human context for the evaluation of pathogenic mutations in congenital heart disease.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Redes Reguladoras de Genes , Proteína Homeótica Nkx-2.5/genética , Células Madre Embrionarias Humanas/metabolismo , Miocitos Cardíacos/metabolismo , Organogénesis/genética , Proteínas Represoras/genética , Potenciales de Acción/fisiología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Diferenciación Celular , Línea Celular , Eliminación de Gen , Regulación del Desarrollo de la Expresión Génica , Proteína Homeótica Nkx-2.5/deficiencia , Células Madre Embrionarias Humanas/citología , Humanos , Miocardio/citología , Miocardio/metabolismo , Miocitos Cardíacos/citología , Técnicas de Placa-Clamp , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Proteínas Represoras/metabolismo , Transcripción Genética , Molécula 1 de Adhesión Celular Vascular/genética , Molécula 1 de Adhesión Celular Vascular/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA