基于转录组学的电刺激对失神经支配大鼠骨骼肌结构和功能保护作用机制

关键词：转录组学  电刺激  失神经支配  骨骼肌  机制研究

Keywords:transcriptomics  electrical stimulation  denervation  skeletal muscle  mechanisms study

摘要：

      摘要 目的：基于转录组学探讨电刺激对完全失神经支配骨骼肌的保护作用及机制。 方法：60只SD大鼠随机分为假手术组（sham，SHAM）、手术组（completely denervation，CDN）和电刺激组（completely denervation + electrical stimulation，CDN+ES）。CDN+ES组于术后接受2Hz电刺激（20min/d，共28d）。通过HE染色、电镜评估结构，离体肌力测试评估功能，RNA-Seq（RNA sequencing）分析分子机制。 结果：①结构保护：CDN+ES组腓肠肌湿重、肌纤维横截面积和直径均显著高于CDN组（均P<0.05），超微结构破坏减轻。②功能保护：CDN+ES组最大收缩力和收缩曲线下面积显著高于CDN组（均P<0.05）。③分子机制：筛选出14个关键基因，显著富集于“蛋白质消化与吸收”（COL3A1、COL5A3等）和“VEGF信号通路”（PPP3CA）。 结论：28d电刺激可部分改善失神经支配骨骼肌的萎缩、超微结构破坏和收缩功能下降，其作用可能与调控细胞外基质重塑和VEGF信号通路有关。

Abstract:

      Abstract Objective： To investigate the protective effects and mechanisms of electrical stimulation （ES） on completely denervated skeletal muscle based on transcriptomics. Method： Sixty Sprague-Dawley (SD) rats were randomly divided into sham operation（SHAM）， complete denervation（CDN）， and denervation plus ES treatment（CDN+ES） groups. The CDN+ES group received 2?Hz ES （20?min/day for 28?days） starting postoperatively. Structural changes were assessed by hematoxcylin-eosin (HE) staining and electron microscopy； contractile function was evaluated by in?vitro muscle force testing， and molecular mechanisms were analyzed via RNA-Seq. Result： ①Structural protection： The CDN+ES group showed significantly increased gastrocnemius wet weight，muscle fiber cross-sectional area， and diameter compared with the CDN group （all?P<0.05）， along with attenuated ultrastructural damage. ②Functional protection： The maximum contraction force and the area under the contraction curve were significantly higher in the CDN+ES group than in the CDN group （both?P<0.05）. ③Molecular mechanism： Fourteen key differentially expressed genes were identified， which were significantly enriched in the “Protein digestion and absorption” pathway （involving COL3A1， COL5A3， etc.） and the “VEGF signaling pathway” （involving PPP3CA）. Conclusion： A 28-day ES regimen can partially ameliorate atrophy， ultrastructural disruption， and contractile dysfunction in denervated skeletal muscle. The protective effects may be associated with the regulation of extracellular matrix remodeling and the VEGF signaling pathway.