The effect of high expression of myogenic differentiation factor D in muscle satellite cells on prevention of denervation muscle atrophy: an experimental study in rats

Objeetive To study the effect of implantation of muscle satellite cells (MSCs) transtected with myogenic differentiation factor D (MyoD) high expression plasmids on denervated gastrocnemius muscle atrophy in rats.Methods Plasmid of high expression of MyoD was constructed and used to transfect MSCs derived from Sprague-Dawley rats.These transfected MSCs were transplanted into the denervated gastrocnemius muscles in a rat sciatic nerve transection model.At 2 and 4 weeks postoperatively,gastrocnemius muscles were harvested for measurement of wet muscle weight and muscle fiber cross sectional area from H&E stained tissue sections.The expression of MyoD was quantified with real-time PCR.Results Confocal microscopy detected MyoD expression in the transfected MSCs with a transfection efficiency of 43 ％.Gastrocnemius muscle wet weight of the MyoD transfected MSC group was higher than those of the other groups (P ＜ 0.05).The level of MyoD gene expression was higher in the MyoD transfected MSC group than in the other groups (P ＜ 0.05).Muscle cell degeneration and cell death was noted in the control group at 2 and 4 weeks postoperatively.Vacuole formation and myofiber rupture were also observed.Myofiber regeneration was present in the MSC group and MyoD transfected MSC group.Muscle fiber cross sectional area in the MyoD transfected MSC group was higher than the other groups at both 2 and 4 week time points.The differences were statistically significant (P ＜ 0.05).Conclusion Transplantation of high MyoD expression MSCs can delay denervation atrophy of gastrocnemius muscle in rats. Key words: Muscular atrophy;  Skeletal muscle satellite cells;  Myogenic differentiation factor D;  Denervated muscle atrophy;  Gene therapy