摘要
目的 探讨MicroRNA-1/133a在失神经骨骼肌萎缩过程中不同部位及时段的表达. 方法 2012年4月-2012年12月,取SD大鼠54只,体质量（200±10）g.随机分成9组,每组6只.切断大鼠右侧坐骨神经（实验组）,左侧行假手术（对照组）,分别于术后0h、8h、1d、3d、1周、2周、3周、4周、8周脊椎脱臼法处死1组大鼠,取其各组大鼠的快肌（腓肠肌、趾长伸肌）和慢肌（比目鱼肌）称重后,保存于-70℃冰箱.分别使用实时荧光定量RT-PCR法对各样本中的MicroRNA-1/133a进行检测并用电镜观察肌纤维超微结构的变化. 结果 大鼠失神经支配后肌肉湿重比随时间推移持续下降；电镜观察肌纤维结构排列逐渐紊乱；RT-PCR观察快慢肌对照组中miRNA-133a和miRNA-1表达均维持在一定的水平,实验组同对照组比较有差异；随时间延长,比目鱼肌实验组miRNA-133a和miRNA-1表达均是先降低后升高,4周时表达最低,8周时高表达；腓肠肌和趾长伸肌实验组中miRNA-133a在1周时表达最低,始终处于低表达,miRNA-1在3d时表达最低,始终处于低表达；快肌中miRNA-133a、miRNA-1表达降低的趋势更早.实验组与对照组比较,差异有统计学意义（P＜0.05）. 结论 MicroRNA-1/133a在大鼠快、慢肌失神经萎缩过程中的表达不同,推测可能是调控快、慢肌本质区别的一个关键点.
Objective To investigate the expression of MicroRNA-1/133a in denervated skeletal muscle at different periods.Methods From April 2012 to December 2012,a total of 54 Sprague-Dawle rats weighted （200 ± 10） g were used.They were randomly divided into 9 groups,each group of 6.The right sciatic nerve was cut off in rats （experimental group）,with the left one being sham operation（control group）at various time points（0 h,8 h,1 d,3 d,1 weeks,2 weeks,3 weeks,4 weeks,8 weeks）.Then after rats were sacrificed by spinal dislocation,the muscle sample（gastrocnemius,extensor digitorum longus and soleus）were harvested and weighed,then stored at-70 degrees.MicroRNA-1/133a were detected in each muscle specimens by RT-PCR.The ultrastructural changes of each muscle specimens at different periods were observed by electron microscopy.Results The muscle wet weight ratio of experimental group decreased gradually over time.Observed by electron microscopy,the different types of muscle fiber were disordered arrangement at different time points.RT-PCR was performed to quantitatively analyze miRNA-1/133a expressions of the fast-twitch muscles （i.e.,gastrocnemius and extensor digitorum longus）and slow-twitch muscle （soleus）.In the control group,miRNA-133 and miRNA-1 expression in the soleus muscles were maintained at a certain level,whereas in the experimental group,these first decreased and then increased,with the lowest at 4 weeks and the highest at 8 weeks.For the gastrocnemius and extensor digitorum longus muscles in the experimental group,the expressions changed with time,whereas in the control group,these were maintained at a certain level.In the experimental group,miRNA-133 at 1 week was the lowest and was always low for all time points,whereas in the experimental group,miRNA-1 expression at 3 days was at a minimum level.The expression of MicroRNA-1/133a in the experimental group had significant differences than the control group （P 〈 0.05）.Conclusion MicroRNA-1/ 133a have differrent expression in rat fast and slow denervation muscle atrophy,presumably.It is a key point in the regulation of fast-twitch and slow-twitch muscle aspects.
出处
《中华显微外科杂志》
CSCD
北大核心
2014年第1期56-62,共7页
Chinese Journal of Microsurgery
基金
国家自然科学基金面上项目，国家自然科学青年基金项目
关键词
失神经
肌萎缩
大鼠
MicroRNA-1/133a
MicroRNA-1/133a
Denervation
Muscle atrophy
Rat
