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La fosforilación de la cadena ligera de miosina es crítica para la adaptación al estrés cardíaco
Sonisha A Warren1, Laura E Briggs, Huadong Zeng
1Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL 32610-0274, USA.
Circulation
|October 26, 2012
Resumen
La degradación acelerada de la quinasa de cadena ligera de miosina cardíaca (cMLCK) por el sistema ubiquitina-proteasoma reduce la fosforilación de la cadena ligera de miosina cardíaca 2 (MLC2v), impulsando la transición de la hipertrofia compensada a la insuficiencia cardíaca.
Área de la Ciencia:
- Cardiología Cardiología.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- La hipertrofia cardíaca es una respuesta compensatoria al estrés, pero el estrés sostenido puede conducir a insuficiencia cardíaca descompensada.
- El mecanismo de transición de la insuficiencia cardíaca compensada a la descompensada es poco conocido.
- La fosforilación de la cadena ligera de miosina cardíaca 2 (MLC2v) mejora la contractilidad, y la quinasa de la cadena ligera de miosina cardíaca (cMLCK) es una enzima clave involucrada.
Objetivo del estudio:
- Investigar el papel de cMLCK en la adaptación cardíaca al estrés.
- Para determinar cómo cambian los niveles de cMLCK y la fosforilación MLC2v durante la sobrecarga de presión.
- Para aclarar los mecanismos subyacentes a la transición a la insuficiencia cardíaca.
Principales métodos:
- Utilizó la constricción transaórtica en ratones de tipo salvaje para inducir una sobrecarga de presión.
- Generó knockout cMLCK y modelos de ratón de sobreexpresión.
- Investigó el efecto de la inhibición del sistema ubiquitina-proteasoma en los niveles de proteína cMLCK.
Principales resultados:
- La sobrecarga de presión redujo significativamente los niveles de MLC2v y cMLCK fosforilados en ratones de tipo salvaje.
- Los ratones knockout de cMLCK desarrollaron insuficiencia cardíaca severa bajo sobrecarga de presión.
- La sobreexpresión de la cMLCK protegió contra la insuficiencia cardíaca, y la inhibición de la degradación de proteínas atenuó la reducción de la cMLCK.
Conclusiones:
- La aceleración de la rotación de la proteína cMLCK a través del sistema ubiquitina-proteasoma contribuye a la reducción de la fosforilación MLC2v.
- Este proceso subyace a la progresión de la hipertrofia cardíaca compensada a la insuficiencia cardíaca descompensada.
- Dirigirse a la estabilidad de la cMLCK puede ofrecer estrategias terapéuticas para la insuficiencia cardíaca.
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