Stability of motor endplates is greater in the biceps than in the interossei in a rat model of obstetric brachial plexus palsy
Stability of motor endplates is greater in the biceps than in the interossei in a rat model of obstetric brachial plexus palsy
复制标题
在产科臂丛神经麻痹大鼠模型中，二头肌运动终板的稳定性高于骨间肌
DOI：
10.4103/1673-5374.276341
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发表时间：
2020-09-01
影响因子：
6.1
通讯作者：
Gu，Yu-Dong
中科院分区：
文献类型：
--
作者：
Li，Bo;Chen，Liang;Gu，Yu-Dong
产瘫下干修复时间窗短于上干修复时间窗。失去神经支配的手的内在肌肉变得不可逆转地萎缩，比失去神经支配的二头肌要快得多。然而，目前尚不清楚去神经的骨间肌肉的运动终板是否比去神经的二头肌的运动终板退化得更快。在这项研究中，我们使用了一种产瘫大鼠的右上肢臂丛神经麻痹模型。C5-6椎间孔远端撕裂，同时伴有C7-8和T1撕脱，以左侧上肢为对照。分别于5周和7周采集双侧骨间和二头肌。用免疫荧光法检测运动终板的形态。用实时定量聚合酶链式反应和免疫印迹法检测乙酰胆碱受体亚单位(α，β和δ)、RAPSYN和β-连环蛋白的基因和蛋白表达水平。免疫荧光显微镜下可见失神经支配的骨间肌内运动终板碎裂，而失神经支配的二头肌运动终板形态完整，碎裂较少。与失神经支配的二头肌相比，失神经支配的骨间肌内运动终板的数目和面积明显低于对照侧。与失神经支配的二头肌相比，失神经支配的骨间肌乙酰胆碱受体亚单位(α，β和δ)的基因和蛋白表达水平显著降低，而β-连环蛋白的表达水平显著升高。7周时，失神经支配的二头肌中Rapsyn的蛋白表达高于失神经支配的骨间肌。我们的发现表明，在产瘫大鼠模型中，骨间运动终板不稳定，而二头肌运动终板保持稳定。所有程序均经复旦大学实验动物伦理委员会中国批准(批准号：东风-187)在2016年1月。
The time window for repair of the lower trunk is shorter than that of the upper trunk in patients with obstetric brachial plexus palsy. The denervated intrinsic muscles of the hand become irreversibly atrophic much faster than the denervated biceps. However, it is unclear whether the motor endplates of the denervated interosseous muscles degenerate more rapidly than those of the denervated biceps. In this study, we used a rat model of obstetric brachial plexus palsy of the right upper limb. C5–6 was lacerated distal to the intervertebral foramina, with concurrent avulsion of C7–8 and T1, with the left upper limb used as the control. Bilateral interossei and biceps were collected at 5 and 7 weeks. Immunofluorescence was used to assess the morphology of the motor endplates. Real-time quantitative polymerase chain reaction and western blot assay were used to assess mRNA and protein expression levels of acetylcholine receptor subunits (α, β and δ), rapsyn and β-catenin. Immunofluorescence microscopy showed that motor endplates in the denervated interossei were fragmented, while those in the denervated biceps were morphologically intact with little fragmentation. The number and area of motor endplates, relative to the control side, were significantly lower in the denervated interossei compared with the denervated biceps. mRNA and protein expression levels of acetylcholine receptor subunits (α, β and δ) were significantly lower, whereas β-catenin protein expression was higher, in the denervated interossei compared with the denervated biceps. The protein expression of rapsyn was higher in the denervated biceps than in the denervated interossei at 7 weeks. Our findings demonstrate that motor endplates of interossei are destabilized, whereas those of the biceps remain stable, in the rat model of obstetric brachial plexus palsy. All procedures were approved by the Experimental Animal Ethics Committee of Fudan University, China (approval No. DF-187) in January 2016.