Effect of exogenous miR206 on the development of denervated muscular atrophy by inhibiting the expression of myostatin of rats / 中华显微外科杂志

ABSTRACT

Objective:To investigate the effects and mechanism of miR206 in rat model of denervated muscular atrophy.Methods:From September, 2020 to December, 2020, a total of 40 rats were selected for this study. Denervated muscular atrophy model was established on 16 SPF Sprague-Dawley rats, by removing 1 cm in length of sciatic nerve. The rats were classified into 4 groups according to the sampling time: 0 d, 3 d, 7 d and 14 d(4 rats per group). The other 24 rats were also established into denervated skeletal muscle atrophy models and assigned into 3 groups: denervation add miR206 group, denervation add NC transfection reagent group, and sham-operated group( n=8 in each group). After sampling, the area of cross section of the gastrocnemius muscle and gastrocnemius muscle mass were measured to evaluate muscle atrophy. The mRNA and protein expression of myostatin were determined by real-time PCR and Western blot. Combining with luciferase report to explore the underlying mechanism of miR206, the t-test and oneway ANOVA were used for data analysis used in this study. In one-way ANOVA analysis, if the difference between groups was statistically significant, Bonferroni method would be used for further comparing of all pairs. P<0.05 was considered statistically significant. Results:After excision of a part of sciatic nerve of rat models, gastrocnemius muscle mass of denervation plus miR206 group, denervation plus NC transfection reagent group and sham-operated group were: (0.63±0.04), (0.51±0.02) and (1.05±0.02), respectively. The cross section areas of gastrocnemius muscle in each groups were: (761.30±21.79) μm 2, (640.30±30.31) μm 2 and (1066.00±51.65) μm 2, respectively( P<0.05). Myostatin mRNA expression showed lower in miR206 group than in NC group tested by Western blot, which were(0.57±0.04) in miR206 and (0.81±0.04) in NC group tested by qPCR( P<0.05). The protein expression measured by Western blot test revealed same expression pattern as mRNA expression pattern. The different of relative expression between miR206 group and NC group( P<0.05). Finally, in the mmu-miR206 co-transfected with the MSTN 3'UTR-luciferase sensor group, the relative luciferase activity was measured at 0.26±0.07 and it was significant lower than any other groups( P<0.05). Conclusion:The miR206 can counteract denervated skeletomuscular atrophy through down regulating the myostatin expression. Myostatin is a new discovered target gene of miR206.