肌肉特异性microRNAs在骨骼肌损伤修复过程中的动态表达

目的探讨3种肌肉特异性microRNAs(miRNAs):miR-1、miR-133和miR-206在骨骼肌损伤修复过程中在肌肉组织中和血清中的动态表达。方法局部注射0.75%盐酸布比卡因(BPVC)制作小鼠腓肠肌损伤模型,采用Real Time RT-PCR方法检测注药后不同时间点3种miRNAs在肌肉组织中和血清中的表达量。结果小鼠一侧腓肠肌注射BPVC后,该侧后肢的活动能力明显较对侧下降;肌肉组织中miR-1、miR-133和miR-206的表达水平均于注射BPVC后先下降后明显上升、维持一段时间后又恢复至接近注药前水平;正常小鼠血清中3种miR-NAs的表达量均很低;血清中miR-1、miR-133和miR-206均于肌肉注射BPVC后早期表达上调,其中miR-1于注药后6～12h表达上调,miR-133于注药后6～24h表达上调,而miR-206于注药后6h表达轻微增高。结论对C57BL/6小鼠而言,局部注射60μl BPVC可制作出稳定的腓肠肌损伤模型,肌肉特异性miRNAs可能在骨骼肌的再生过程中发挥了一定调控作用,有望成为肌肉疾病的潜在治疗靶点;骨骼肌损伤时释放miRNAs到血清中,肌肉特异性miRNAs有望作为肌肉疾病的诊断指标之一。

Dynamic expressions of muscle-specific microRNAs during injury-repair process of skeletal muscle

Objective To explore the temporal expression patterns of muscle-specific microRNAs(miR-1,miR-133 and miR-206)in muscle and serum during a degeneration-regeneration process of mouse gastrocnemius muscles.Methods Muscle injury was performed on gastrocnemius muscles of 7-week-old C57BL/6(B6)mice by injecting 60ul 0.75%Bupivacaine hydrochloride(BPVC).Real Time RT-PCR was used to examine the expression levels of muscle-specific microRNAs in the injuring mouse gastrocnemius mucle and serum at different time points after-injection.Results We observed that the leg’ ability of movement was obviously damaged after injection.The expression of miR-1,miR-133 and miR-206 decreased firstly,then increased markedly,and gradually recovered in gastrocnemius muscles during a degeneration-regeneration process induced by BPVC.The three muscle-specific microRNAs serum levels of normal mouse were very low and increased at early stage after injecting BPVC in gastrocnemius muscle.MiR-1 serum level increased from 6h to 12h after injection,miR-133 serum level increased from 6h to 24h after injection,and miR-206 serum level increased slightly at 6h after injection.Conclusion We presume that muscle-specific microRNAs might reflect active regeneration of skeletal muscle fibers and muscle-specific microRNAs are released from injuryed muscle to blood.Muscle-specific microRNAs could be potential targets for treating muscle diseases and biomarkers of muscle damage.