电针通过调控微小RNA对失神经肌萎缩大鼠肌卫星细胞增殖的影响

Effect of electroacupuncture on muscular atrophy and expression of microRNAs and muscle satellite cell proliferation related proteins in denervated gastrocnemius muscle rats

目的:观察电针干预对失神经肌萎缩大鼠腓肠肌中微小RNA-1(Mir-1)、微小RNA-133a(Mir-133a)、微小RNA-133b(Mir-133b)、配对盒转录因子Pax7、组蛋白脱乙酰酶4(HDAC4)表达的影响,探讨电针延缓失神经肌萎缩的机制。方法:SD大鼠随机分为假手术组、模型组和电针组,每组8只。横断坐骨神经制备大鼠右后肢失神经肌萎缩模型。电针组电针大鼠患侧'足三里''环跳',每次10 min,每日1次,连续干预2周。电针干预结束后称取并计算各组大鼠的腓肠肌湿重比,HE染色后测定腓肠肌纤维横截面积,实时荧光定量PCR法检测各组大鼠腓肠肌中Mir-1、Mir-133a、Mir-133b、HDAC4 mRNA、Pax7 mRNA的相对表达量。结果:造模2周后,模型组大鼠腓肠肌湿重比和肌纤维横截面积明显低于假手术组(P<0. 01);与模型组相比,电针组大鼠腓肠肌湿重比和肌纤维横截面积显著增加(P<0. 01)。与假手术组相比,模型组腓肠肌中Mir-1、Mir-133a相对表达量降低,HDAC4 mRNA和Mir-133b相对表达量升高(P<0. 05),Pax7mRNA相对表达量无明显变化(P>0. 05);电针组术侧腓肠肌中Pax7、HDAC4 mRNA相对表达量较模型组增加(P<0. 05),Mir-1、Mir-133a、Mir-133b相对表达量较模型组减少(P<0. 05)。结论:电针干预可能通过抑制失神经肌萎缩大鼠腓肠肌中Mir-1、Mir-133a、Mir-133b的表达,增加Pax7、HDAC4 mRNA的表达,促进失神经肌萎缩大鼠肌卫星细胞的增殖。

ObjectiveTo investigate the effect of electroacupuncture(EA)on muscular atrophy and expression of microRNAs(Mir-1,Mir-133 a,Mir-133 b)and some proliferation-related factors of muscle satellite cells as histone deacetylase4(HDAC4)and the paired box transcription factor Pax7(Pax7)in skeletal muscle atrophy rats.Methods Twenty-four male SD rats were randomly and equally divided into sham operation,model and EA groups.The skeletal muscle atrophy model was established by transection of the right sciatic nerve.EA(2 Hz,1 mA)was applied to the right'Zusanli'(ST36)and'Huantiao'(GB30)for 10 min,once a day,seven times a week for 2 weeks.The wet weight of bilateral gastrocnemius muscles was measured to calculate the ratio of weight between the affected gastrocnemius muscle and healthy gastrocnemius muscle.The cross-sectional area(CSA)of the gastrocnemius muscle on the affected side was measured after H.E.staining.The expression levels of Mir-1,Mir-133 a,Mir-133 b,HDAC4 mRNA and Pax7 mRNA in the gastrocnemius muscle tissue were detected using quantitative real time-PCR.ResultsCompared with the sham operation group,the ratio of wet weight and CSA of the gastrocnemius muscle,and the expression levels of Mir-1 and Mir-133 a were significantly decreased in the model group(P<0.01,P<0.05),while the expression levels of HDAC4 mRNA and Mir-133 b significantly up-regulated in the model group(P<0.05).Following EA intervention,the decreased levels of the ratio of wet weight and CSA of the gastrocnemius muscle were significantly suppressed(P<0.01),suggesting an inhibition of the skeletal muscle atrophy,and the expression levels of Pax7 and HDAC4 mRNAs were notably upregulated(P<0.05),and those of Mir-1,Mir-133 a and Mir-133 b were significantly or further significantly down-regulated relevant to the model group(P<0.05).ConclusionEA intervention can delay muscular atrophy in rats with denervated gastrocnemius muscle,which may be related with its function in up-regulating the expression of Pax7 and HDAC4 mRNAs and down-regulating the expression of Mir-1,Mir-133 a and Mir-133 b.