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SMN-deficiency disrupts SERCA2 expression and intracellular Ca(2+) signaling in cardiomyocytes from SMA mice and patient-derived iPSCs

Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by loss of alpha motor neurons and skeletal muscle atrophy. The disease is caused by mutations of the SMN1 gene that result in reduced functional expression of survival motor neuron (SMN) protein. SMN is ubiquitously expresse...

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Detalles Bibliográficos
Autores principales: Khayrullina, Guzal, Moritz, Kasey E., Schooley, James F., Fatima, Naheed, Viollet, Coralie, McCormack, Nikki M., Smyth, Jeremy T., Doughty, Martin L., Dalgard, Clifton L., Flagg, Thomas P., Burnett, Barrington G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7206821/
https://www.ncbi.nlm.nih.gov/pubmed/32384912
http://dx.doi.org/10.1186/s13395-020-00232-7
Descripción
Sumario:Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by loss of alpha motor neurons and skeletal muscle atrophy. The disease is caused by mutations of the SMN1 gene that result in reduced functional expression of survival motor neuron (SMN) protein. SMN is ubiquitously expressed, and there have been reports of cardiovascular dysfunction in the most severe SMA patients and animal models of the disease. In this study, we directly assessed the function of cardiomyocytes isolated from a severe SMA model mouse and cardiomyocytes generated from patient-derived IPSCs. Consistent with impaired cardiovascular function at the very early disease stages in mice, heart failure markers such as brain natriuretic peptide were significantly elevated. Functionally, cardiomyocyte relaxation kinetics were markedly slowed and the T(50) for Ca(2+) sequestration increased to 146 ± 4 ms in SMN-deficient cardiomyocytes from 126 ± 4 ms in wild type cells. Reducing SMN levels in cardiomyocytes from control patient IPSCs slowed calcium reuptake similar to SMA patent-derived cardiac cells. Importantly, restoring SMN increased calcium reuptake rate. Taken together, these results indicate that SMN deficiency impairs cardiomyocyte function at least partially through intracellular Ca(2+) cycling dysregulation.