Neuromuscular electrical stimulation alleviates stroke-related sarcopenia by promoting satellite cells myogenic differentiation via AMPK-ULK1-Autophagy axis

Background

Stroke-related sarcopenia can result in muscle mass loss and muscle fibers abnormality, significantly affecting muscle function. The clinical management of stroke-related sarcopenia still requires further research and investigation. This study aims to explore a promising therapy to restore muscle function and promote muscle regeneration in stroke-related sarcopenia, providing a new theory for stroke-related sarcopenia treatment.

Methods

Stroke-related sarcopenia rat model was established by using permanent middle cerebral artery occlusion (pMCAO) rat and treated with neuromuscular electrical stimulation (NMES). Electrical stimulation (ES) treatment in vitro was mimicked to test the effect of NMES on muscle regeneration in rat skeletal muscle satellite cells (MuSCs). Catwalk, H&E and Masson's trichrome staining, immunofluorescence, transcriptomic analysis, transmission electron microscopy, MuSCs transfection, autophagy flux detection, quantitative real-time PCR analysis, Co-Immunoprecipitation and Western Blot were used to investigate the role of NMES and its mechanism in stroke-related sarcopenia in vivo.

Results

After NMES treatment, muscle mass and myogenic differentiation were significantly increased in stroke-related sarcopenia rats. The NMES group had more stable gait, neater footprints, higher muscle wet weight, more voluminous morphology and more regenerated muscle fibers. Additionally, ES treatment induced myogenic differentiation in rat MuSCs in vitro. Transcriptomic analysis also showed that “AMPK signaling pathway” was enriched and genes upregulated in ES-treated cells, revealing ES treatment could activate the autophagy in an AMPK-ULK1-dependent mechanism in MuSCs. Besides, it was also founded that infusion of AMPK or ULK1 inhibitor, knockdown of AMPK or ULK1 in MuSCs could block the effect of myotube formation of ES.

Conclusion

NMES not only restores muscle function but also enhances myogenic activity and muscle regeneration via AMPK-ULK1 autophagy in stroke-related sarcopenia rats. Our study provides a promising strategy for the treatment of stroke-related sarcopenia.

The translational potential of this article

This study first demonstrates that NMES alleviates stroke-related sarcopenia by promoting MuSCs differentiation through AMPK-ULK1-autophagy axis. The findings reveal a novel therapeutic mechanism, suggesting that NMES can restore muscle function and enhance regeneration in stroke patients. By combining NMES with MuSCs-based therapies, this approach offers a promising strategy for clinical rehabilitation, potentially improving muscle mass and function in stroke survivors. The translational potential lies in its applicability to non-invasive, cost-effective treatments for sarcopenia, enhancing patients' quality of life.