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La disfunción mitocondrial y la apoptosis subyacen al proceso patógeno en la cardiomiopatía relacionada con la
Alina Maloyan1, Atsushi Sanbe, Hanna Osinska
1Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital, Cincinnati, Ohio, USA.
Circulation
|December 1, 2005
Resumen
La alfa-B-cristalina mutante (CryAB) causa cardiomiopatía relacionada con la desmina al interrumpir la estructura mitocondrial-sarcomérica. Esto conduce a la insuficiencia cardíaca a través de la función mitocondrial deteriorada y la apoptosis.
Área de la Ciencia:
- Biología Cardiovascular Biología Cardiovascular
- Biología mitocondrial Biología mitocondrial
- La proteinopatía es una proteopatía.
Sus antecedentes:
- Las mitocondrias y los sarcómeros mantienen una relación arquitectónica crítica dependiente del citoesqueleto.
- Una mutación específica (R120G) en la cristalina alfa-B (CryAB) causa cardiomiopatía relacionada con la desmina, marcada por agregados amiloide-positivos de CryAB y desmin.
- Esta enfermedad se puede modelar en ratones a través de la expresión específica cardíaca del mutante CryAB.
Objetivo del estudio:
- Investigar los efectos inmediatos de la expresión de R120G CryAB en la estructura y función de los cardiomiocitos.
- Para dilucidar la secuencia de eventos que conducen a la insuficiencia cardíaca en la cardiomiopatía relacionada con desmin.
Principales métodos:
- Estudios in vitro en los que se utilizó la transfección mediada por adenovirus de cardiomiocitos adultos con R120G CryAB.
- Estudios in vivo en ratones transgénicos con expresión cardíaca específica de R120G CryAB.
- Evaluación de la mecánica contráctil, la integridad citoesquelética, la organización mitocondrial, el consumo de oxígeno y las vías apoptóticas.
Principales resultados:
- In vitro, la expresión de R120G alteró la mecánica contráctil de los cardiomiocitos.
- In vivo, las perturbaciones tempranas del citoesqueleto precedieron a la disfunción de los órganos, con cambios arquitectónicos mitocondriales observados.
- La disfunción mitocondrial incluía una respiración ligada al complejo I reducida, un poro de transición de permeabilidad alterado y una disminución del potencial de la membrana interna, seguido de apoptosis e insuficiencia cardíaca.
Conclusiones:
- La disfunción del acompañante cardíaco, ejemplificada por R120G CryAB, deteriora agudamente la mecánica de los cardiomiocitos y la arquitectura del sarcomero mitocondrial.
- Estas perturbaciones conducen a la disfunción mitocondrial, la activación de la apoptosis y, en última instancia, a la insuficiencia cardíaca.
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