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El ADN mitocondrial que escapa de la autofagia causa inflamación y insuficiencia cardíaca
Takafumi Oka1, Shungo Hikoso, Osamu Yamaguchi
1Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
Nature
|April 27, 2012
Resumen
El ADN mitocondrial que escapa de la autofagia desencadena la inflamación en las células del corazón, causando insuficiencia cardíaca. El bloqueo del receptor 9 de tipo Toll (TLR9) previene esta respuesta inflamatoria y protege contra el daño cardíaco.
Área de la Ciencia:
- Biología Cardiovascular Biología Cardiovascular
- Inmunología Inmunología.
- Biología celular Biología celular.
Sus antecedentes:
- La insuficiencia cardíaca es una de las principales causas de muerte, y la inflamación juega un papel clave en su desarrollo.
- Los mecanismos precisos que inician la inflamación cardíaca no se comprenden completamente.
- Las mitocondrias, originarias de las bacterias, contienen ADN que potencialmente puede desencadenar respuestas inmunes.
Objetivo del estudio:
- Para investigar el papel del ADN mitocondrial en el inicio de respuestas inflamatorias dentro de los cardiomiocitos.
- Aclarar los mecanismos por los cuales las mitocondrias dañadas contribuyen a la patogénesis de la insuficiencia cardíaca.
- Para explorar posibles objetivos terapéuticos para la enfermedad cardíaca inducida por la inflamación.
Principales métodos:
- Se estudiaron ratones con una deleción específica del corazón de la desoxirribonucleasa lisosomal (DNase) II.
- Sobrecarga de presión inducida para imitar el estrés cardíaco.
- Se han administrado oligodeoxinucleótidos inhibidores contra el receptor 9 de tipo Toll (TLR9).
- Analizó marcadores inflamatorios, expresión de citoquinas e histología cardíaca.
Principales resultados:
- El ADN mitocondrial que escapa de la autofagia induce una inflamación mediada por el receptor 9 de tipo Toll (TLR9), lo que lleva a miocarditis y cardiomiopatía dilatada.
- La deficiencia de DNase II exacerbada por la insuficiencia cardíaca inducida por sobrecarga de presión, caracterizada por inflamación y acumulación de ADN mitocondrial.
- Inhibición o ablación de la inflamación y disfunción cardíaca atenuada por TLR9 en ratones con deficiencia de DNasa II y ratones de tipo salvaje.
Conclusiones:
- La liberación de ADN mitocondrial de las mitocondrias dañadas es un desencadenante clave para la inflamación dependiente de TLR9 en el corazón.
- La DNasa II juega un papel crucial en la limpieza del ADN mitocondrial, previniendo la acumulación del autolisosoma y la posterior inflamación.
- Dirigirse a TLR9 ofrece una estrategia terapéutica potencial para la insuficiencia cardíaca inflamatoria.
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