Sex difference, proteostasis and mitochondrial function impact stroke-related sarcopenia-A systematic review and meta-analysis

BACKGROUND

The prevalence of stroke-related sarcopenia has been noted; however, epidemiological data and interventions that increase or reduce the incidence of stroke-related sarcopenia remain lacking.

METHODS

Studies on stroke-related sarcopenia were included in association or interventional analyses. All analyses were performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two evaluators independently extracted the data.

RESULTS

Female stroke patients had a higher preference for sarcopenia than male patients (pooled odds ratio [OR] = 0.670, 95 % CI 0.533-0.842, p = 0.001). Although stroke patients without drug use have improved skeletal muscle mass index (SMI) (MD = 0.272, 95 % CI 0.087-0.457, p = 0.004), handgrip strength (HGS) was not significantly altered (MD = -0.068, 95 % CI -0.221-0.076, p = 0.354). Stroke patients with nutrient interventions have improved SMI (MD = -0.354, 95 % CI -0.635- -0.073, p = 0.014) and HGS (MD = -0.394, 95 % CI -0.678- -0.111, p = 0.006); the synergistic effect of rehabilitation exercise has not been ruled out. Whether a sex difference exists in these interventions remains to be investigated. The underlying pathological mechanisms and potential therapeutic strategies for this disease are discussed.

CONCLUSION

Sex difference, proteostasis, and mitochondrial function may impact the incidence of stroke-related sarcopenia. Understanding the underlying pathological mechanisms and potential therapeutic targets for this disease will provide new insights into disease treatment, prevention, and drug development.

Factors influencing the reduction in quadriceps muscle thickness in the paretic limbs of patients with acute stroke

BACKGROUND & AIMS

Muscle atrophy is an early event that occurs after stroke, but there are few reports on the changes in skeletal muscle thickness in acute stroke. This study investigated the factors contributing to reduced muscle thickness in patients with acute stroke.

METHODS

In total, 51 patients with stroke and the National Institute of the Health Stroke Scale (NIHSS) > 3 were included in our study. They were admitted to our hospital between July 2017 and May 2020. The quadriceps muscle thickness was measured with an ultrasound device within 2 days after admission and 14 days later. The collected data included age, sex, body mass index, stroke type, neuromuscular electrical stimulation, NIHSS, serum albumin at admission, start of enteral nutrition, Functional Oral Intake Scale (FOIS), start of mobilization and ambulation, number of physical and occupational therapy units, C-reactive protein at admission and whether surgery had been performed. These data were retrospectively retrieved from medical documents. A dietician calculated energy intake, protein intake, and energy adequacy. Multiple regression analysis was used to identify the factors associated with reduced quadriceps muscle thickness. The independent variables were NIHSS, date of start of enteral feeding, protein intake, FOIS, date of mobilization, and date of start of ambulation training.

RESULTS

The rate of change in quadriceps muscle thickness of the paretic limb was -15.3 % (interquartile range, -46.1-14.8 %). Multiple regression analysis showed that the factors responsible for the decrease in muscle thickness on the paretic side were FOIS (β: 0.376; 95 % Cl, 0.999 to 4.541) and the start date of ambulation (β: -0.378; 95 % Cl, -2.575 to -0.543), with a multiple correlation coefficient of 0.456.

CONCLUSION

The FOIS and the start date of ambulation after acute stroke were related to the rate of reduction in muscle thickness on the paretic side.

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.