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Measurement of Calcium Fluctuations Within the Sarcoplasmic Reticulum of Cultured Smooth Muscle Cells Using FRET-based Confocal Imaging
Published on: June 20, 2016
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La excesiva expresión de Ca2+-ATPasa en el retículo sarcoplásmico/endoplásmico causa un aumento de la absorción de
Nils Teucher1, Juergen Prestle, Tim Seidler
1Department of Cardiology and Pneumology, University of Goettingen, Goettingen, Germany.
Circulation
|October 27, 2004
Resumen
El aumento de la expresión de Ca2+-ATPasa (SERCA) en el retículo sarcoplasmático/endoplasmático puede mejorar la función cardíaca. Sin embargo, la expresión excesiva de SERCA1a puede, paradójicamente, deteriorar la contractilidad de los miocitos debido al aumento de la actividad y el amortiguamiento del calcio.
Área de la Ciencia:
- Cardiología Cardiología.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- La actividad de la Ca2+-ATPasa (SERCA) del retículo sarcoplasmático/endoplasmático es crucial para la función cardíaca.
- Mejorar la absorción de SERCA es una estrategia terapéutica potencial para la insuficiencia cardíaca.
- El impacto de los diferentes niveles de expresión de SERCA1a en la contractilidad cardíaca y el manejo del calcio requiere más investigación.
Objetivo del estudio:
- Para investigar los efectos de los diferentes niveles de expresión de la Ca2+-ATPasa 1a (SERCA1a) en el retículo sarcoplasmático/endoplasmático sobre la contractilidad de los miocitos y el ciclo del calcio.
- Para determinar si el aumento de la expresión de SERCA1a aumenta la contractilidad de los miocitos de una manera dependiente de la dosis del gen.
Principales métodos:
- Los cardiomiocitos aislados de conejo fueron transfectados con adenovirus que codifican SERCA1a en diferentes multiplicidades de infección (MOI).
- Los grupos de control recibieron adenovirus que codifican para la beta-galactosidasa.
- Se midió la relajación de los miocitos, el acortamiento fraccionario, la absorción de Ca2+ en el retículo sarcoplásmico y la amplitud transitorio de Ca2+.
Principales resultados:
- La expresión moderada de SERCA1a (MOI 10) mejoró la relajación y el acortamiento fraccionario de los miocitos, y aumentó la amplitud transitorio de Ca2+ y el contenido de Ca2+ SR.
- Una mayor expresión de SERCA1a (MOI 50) condujo a una disminución del acortamiento de los miocitos, a pesar de la mejora de la cinética de absorción de Ca2+ de SR (disminución de Km, aumento de Vmax).
- Las simulaciones matemáticas indicaron que la actividad elevada de SERCA y el amortiguamiento citosólico de Ca2+ a altos niveles de expresión redujeron la amplitud transitorio de Ca2+, lo que explica la reducción de la contracción.
Conclusiones:
- La transferencia genética moderada de SERCA1a puede mejorar la contractilidad cardíaca y el ciclo del calcio.
- Los niveles suprafisiológicos de la expresión de SERCA1a pueden afectar negativamente el acortamiento de los miocitos.
- Las estrategias terapéuticas dirigidas a SERCA deben considerar cuidadosamente los niveles óptimos de expresión para evitar efectos perjudiciales.
Palabras clave:
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