Kodama Haruka, Kumai Yoshihiko, Nishimoto Kohei, Sanuki Tetsuji, Yumoto Eiji
Department of Otolaryngology Head and Neck Surgery, Kumamoto University, Graduate School of Medicine, Kumamoto, Japan.
Laryngoscope. 2015 Jul;125(7):E245-51. doi: 10.1002/lary.25248. Epub 2015 Mar 26.
OBJECTIVES/HYPOTHESIS: To examine modulation of M-cadherin, a marker for satellite cells (SCs); and MyoD, which may indicate the myogenic activity following recurrent laryngeal nerve (RLN) denervation and immediate reinnervation; and to elucidate the correlation between their modulations and establishment of neuromuscular junctions (NMJs) in the reinnervated rat thyroarytenoid (TA) muscle.
Quantitative real-time polymerase chain reaction qPCR and histologic assessment of the TA muscle following RLN transection and anastomosis.
Rats were divided into three groups: 1) denervation alone (DNV) (n = 60), 2) denervation with anastomosis (ANS) (n = 60), and 3) sham-operated controls (n = 12). Animals were sacrificed at 3 days and 1, 3, and 5 weeks after treatment. TA muscles harvested from 40 animals from each DNV and ANS group; all of sham group were subjected to qPCR for assessment of the modulation of M-cadherin and MyoD; and the remaining larynges of DNV and ANS group were used for histologic analysis.
The expression levels of messenger RNAs (mRNAs) encoding M-cadherin and MyoD in the TA muscle of the DNV group were significantly higher (P < 0.05) than in the control throughout the study period. These mRNA levels in the ANS group were significantly higher (P < 0.05) at ≤ 1 week than in the controls but fell to control levels at ≥ 3 weeks. In the ANS group, recovery of muscle area and NMJs structure occurred by 3 weeks.
These data suggested that NMJ formation following reinnervation might prompt recovery of M-cadherin and MyoD mRNA expression to the quiescent level of SCs.
目的/假设：研究卫星细胞（SCs）标志物M-钙黏蛋白的调节情况；以及肌分化抗原（MyoD），其可能指示喉返神经（RLN）去神经支配及即刻再支配后的生肌活性；并阐明它们的调节与再支配大鼠甲杓肌（TA）中神经肌肉接头（NMJs）建立之间的相关性。
对RLN横断和吻合术后的TA肌进行定量实时聚合酶链反应（qPCR）和组织学评估。
将大鼠分为三组：1）单纯去神经支配组（DNV）（n = 60），2）去神经支配并吻合组（ANS）（n = 60），3）假手术对照组（n = 12）。在治疗后3天、1周、3周和5周处死动物。从每个DNV组和ANS组的40只动物中采集TA肌；对所有假手术组进行qPCR以评估M-钙黏蛋白和MyoD的调节情况；DNV组和ANS组其余的喉部用于组织学分析。
在整个研究期间，DNV组TA肌中编码M-钙黏蛋白和MyoD的信使核糖核酸（mRNAs）表达水平显著高于对照组（P < 0.05）。ANS组中这些mRNA水平在≤1周时显著高于对照组（P < 0.05），但在≥3周时降至对照水平。在ANS组中，肌肉面积和NMJs结构在3周时恢复。
这些数据表明，再支配后NMJ的形成可能促使M-钙黏蛋白和MyoD mRNA表达恢复到SCs的静止水平。
