Diarylpropionitrile-stimulated ERß nuclear accumulation promotes MyoD-induced muscle regeneration in mdx mice by interacting with FOXO3A.

ABSTRACT

Duchenne muscular dystrophy (DMD) is an X-linked recessive progressive degenerative disease of skeletal muscle, characterized by intramuscular inflammation, muscle regeneration disorder and replacement of muscle with fibroadipose tissue. DMD is caused by the absence of normal dystrophy. Impaired self-renew ability and limited differentiation capacity of satellite cells are proved as main reasons for muscle regeneration failure. The deficiency of estrogen impedes the process of muscle regeneration. However, the role of estrogen receptor ß (ERß) in muscle regeneration is still unclear. This study aims to investigate the role and the pharmacological effect of ERß activation on muscle regeneration in mdx mice. This study showed that mRNA levels of ERß and myogenic-related genes both witnessed increasing trends in dystrophic context. Our results revealed that treatment with selective ERß agonist (DPN, diarylpropionitrile) significantly increased myogenic differentiation 1 (MyoD-1) level and promoted muscle regeneration in mdx mice. Similarly, in mdx mice with muscle-specific estrogen receptor α (ERα) ablation, DPN treatment still promoted muscle regeneration. Moreover, we demonstrated that myoblasts differentiation was accompanied by raised nuclear accumulation of ERß. DPN treatment augmented the nuclear accumulation of ERß and, thus, contributed to myotubes formation. One important finding was that forkhead box O3A (FOXO3A), as a pivotal transcription factor in Myod-1 transcription, participated in the ERß-promoted muscle regeneration. Overall, we offered an interesting explanation about the crucial role of ERß during myogenesis.