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El músculo esquelético Rac1 media las adaptaciones del entrenamiento hacia la resíntesis de glucógeno muscular y la

Steffen H Raun¹, Carlos Henriquez-Olguín², Emma Frank¹

¹The Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.

|August 31, 2025

Resumen

La Rho GTPasa Rac1 es crucial para la adaptación muscular al ejercicio. La pérdida de Rac1 afecta el crecimiento muscular y la capacidad de ejercicio, destacando su papel en la respuesta del músculo esquelético al entrenamiento.

Área de la Ciencia:

Fisiología del ejercicio
Biología molecular
Biología del músculo esquelético

Sus antecedentes:

El ejercicio a largo plazo ofrece beneficios para la salud, pero los mecanismos moleculares siguen sin estar claros.
Las GTPasas Rho, particularmente Rac1, se alteran significativamente en el músculo esquelético después del ejercicio.
La identificación de objetivos moleculares mediadores del ejercicio es esencial para el desarrollo terapéutico.

Objetivo del estudio:

Investigar el papel de la Rho GTPasa Rac1 en la adaptación del músculo esquelético al entrenamiento físico.
Para aclarar las vías moleculares a través de las cuales Rac1 influye en la respuesta muscular al ejercicio.
Determinar las consecuencias funcionales de la modulación de Rac1 en el rendimiento y la adaptación muscular.

Principales métodos:

Análisis de la activación de Rac1 en el músculo esquelético humano después del ejercicio agudo.
Utilizando modelos genéticos de ratón con deficiencia o ganancia de función Rac1 específica para el músculo.
Empleando técnicas como el Western blotting, las pruebas de capacidad de ejecución, las evaluaciones de hipertrofia muscular y la proteómica basada en la espectrometría de masas.

Principales resultados:

La activación de Rac1 se observó agudamente en el músculo esquelético humano después del ejercicio.
La pérdida de Rac1 específica del músculo en ratones redujo la síntesis de proteínas, la capacidad de ejercicio y la hipertrofia.
Se encontró que Rac1 regula la resíntesis de glucógeno a través de una vía dependiente de NOX2 y es esencial para la señalización inducida por la contracción.
El análisis proteómico reveló que Rac1 afecta la organización del citoesqueleto, la adaptación muscular y las vías ribosómicas.

Conclusiones:

El músculo esquelético Rac1 es un mediador clave de las adaptaciones moleculares y funcionales al entrenamiento físico.
Rac1 juega un papel crítico en la síntesis de proteínas musculares inducida por el ejercicio, la mejora del rendimiento y la hipertrofia.
Dirigirse a Rac1 puede ofrecer estrategias terapéuticas para mejorar la salud muscular y la respuesta al ejercicio.

Palabras clave:

La contracción Entrenamiento físico Glicógeno El metabolismo Hipertrofia de los músculos Síntesis de proteínas Rac1 y Rac2 El músculo esquelético

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