喉返神经缺损后损伤近端神经组织miR-221和PTEN表达变化

Changes of miR-221 and PTEN expressive activities in the proximal end nervous tissue of defected recurrent laryngeal nerve among rats

目的研究大鼠喉返神经缺损后损伤近端神经组织中miR 221和PTEN达水平变化与神经修复过程的相关性。方法建立大鼠喉返神经缺损模型,应用Real time RT PCR技术分别于第0d(对照组)、Id、4d和7d时检测喉返神经缺损后损伤近端神经组织的miR-221和PTEN表达活性水平,评估其活性表达变化与神经修复过程的相关性。结果喉返神经缺损后第0d、d1、d4和d7,损伤处近端神经组织中miR 221表达量分别为0.067±0.005、0.073±0.004、0.116±0.006和0.148±0.003;PTEN表达量分别为0.115±0.008、0.103±0.003、0.056±0.006和0.032±0.002;与对照组比较,第4d和第7d miR 221表达水平均上调,而PTEN则呈下调趋势,差异均有显著性统计学意义(P<0.05)。结论大鼠喉返神经缺损后,损伤近端神经组织中miR 221表达上调,并可能通过调控PTEN表达水平而对神经组织修复过程发挥促进作用。

Objective To investigate the expressive activity changes of miR-221 and PTEN in the proximal end nervous tissue of defected recurrent laryngeal nerve among rats. Methods Damage mode of recurrent laryngeal nerve disjunction was established among rats at first, and then, real time RT-PCR technique was utilized to determine the expressive levels of miR-221 and PTEN in the proximal end nervous tissue of disjuncted recurrent laryngeal nerve at 0 day, day 1, day 4 and day 7 respectively, with the healthy nervous tissue as normal control （day 0） to evaluate the possible association of miR-221 and PTEN expressive activities with recurrent laryngeal nerve reparation. Results The expressive levels of miR-221 in the proximal end nervous tissue of disjuncted recurrent laryngeal nerve were 0.067±0.005, 0.073±0.004, 0.116±0.006 and 0.148±0.003 at d0, d1, d4 and d7 respectively, while, that of PTEN were 0.115±0.008, 0.103±0.003, 0.056±0.006 and 0.032±0.002 at these time points respectively. When compared with that of controls, the expressive activities of miR-221 were significantly up-regulated but that of PTEN were obviously down-regulated in the proximal nerve tissue at d4 and d7 respectively, with statistic significances among them （P〈0.05）. Conclusions As shown clearly from this study, the expressive activity of miR-221 is up-regulated in the proximal nerve tissue of disjuncted recurrent laryngeal nerve in rats during the period of nerve reparation. Then, it may play a role in regeneration of injured recurrent laryngeal nerve by regulating PTEN expression in a down-regulated way.