ABSTRACT
OBJECTIVE: To explore the effect of electroacupuncture (EA) serum on expression of myogenic differentiation antigen (Myod) and autophagy-related protein Beclin 1 in cultured muscle satellite cells of rats under starvation conditions. METHODS: The primary multifidus muscle satellite cells of one male SD rat were isolated and cultured to obtain the 3rd generation of cells. The EA serum was got from the rat received EA stimulation of bilateral "Weizhong" (BL40, 2 Hz/10 Hz, 1 mA, duration of 20 min, once daily for 7 days). The cell suspension (2×104/well) of the 3rd generation of cultured cells was transferred to each well of a 96-well plate in medium containing 10% fetal bovine serum (FBS). Twelve duplicate wells were set up for the blank control serum (without FBS), 10% FBS, 10% EA serum, 20% EA serum and 30% EA serum groups and incubated for 12 h and 24 h, respectively. Each well was supplemented with 10 µL CCK-8 reagent to be incubated for 1 h again for observing the state of cell proliferation. After culturing the primary muscle satellite cells in serum-free medium for 12 h, the cells were randomly divided into serum-free group, 10% fetal bovine serum group and optimal concentration electroacupuncture serum group, and serum of corresponding concentration was added respectively. The expression levels of Beclin 1 and cell-proliferation-related protein Myod were detected by Western blot. RESULTS: CCK-8 assay displayed that the proliferation levels were significantly higher at 12 h and 24 h after serum intervention in the 10% FBS, 10% EA serum, 20% EA serum and 30% EA serum groups than that in the blank control serum group (P0.05). As a result, 10% EA serum was selected as the optimal concentration for Western blot tests. No significant difference was found in the expression levels of Myod and Beclin 1 proteins among the serum-free, 10% FBS and 10% EA serum groups before intervention (P>0.05), and there was a marked up-regulation of Myod expression and an obvious down-regulation of Beclin 1 expression at 12 h in both the 10% EA serum and 10% FBS groups in comparison with their own pre-intervention (P0.05). CONCLUSION: EA serum can promote proliferation of cultured muscle satellite cells under starvation conditions, which is related to its functions in regulating expression of Beclin 1 and cell-proliferation-related protein Myod.