链霉素损伤后小鼠前庭毛细胞再生和神经支配

发布时间：2019-04-28 13:01

【摘要】： 目的：研究两种不同剂量的链霉素损伤后,小鼠前庭感觉上皮中毛细胞再生情况。 方法：通过左耳后半规管将两种不同剂量的链霉素注入小鼠前庭,分别建立小鼠前庭感觉上皮中度和重度损伤模型。术后不同时间点行椭圆囊免疫荧光染色、扫描电镜和树脂切片,观察不同程度损伤后椭圆囊感觉上皮的形态特征及毛细胞再生情况。 结果：椭圆囊前庭感觉上皮中度损伤后,毛细胞严重缺失,支持细胞保存良好；损伤后2周内出现以幼小纤毛为特征的新生毛细胞,并随着时间延长而增多；但是新生毛细胞的形态有别于正常毛细胞,而且再生的毛细胞数目有限。重度损伤后,毛细胞和支持细胞均受到严重损害,前庭感觉上皮被一极薄的单层扁平上皮取代；毛细胞的自我再生能力较中度损伤时极度减弱；部分细胞无毛细胞或支持细胞的特征。 结论：链霉素损伤后,小鼠前庭感觉上皮具有有限的自我再生能力。重度损伤极度降低了这种再生能力,前庭感觉上皮被一极薄的单层扁平上皮取代。 目的：探讨小鼠前庭毛细胞再生过程中Notch信号途径因子和Atoh1的作用。 方法：通过后半规管途径将链霉素注入小鼠前庭,建立小鼠前庭感觉上皮中度损伤模型。然后我们分别用免疫荧光染色和实时定量PCR的方法检测椭圆囊前庭感觉上皮中Notch信号途径因子(Notch1, Jagged1, Hes1, Hes5)及Atoh1的蛋白和mRNA的表达。 结果：免疫组化结果显示Jagged1表达于正常和损伤后支持细胞的细胞膜；Atoh1在正常小鼠前庭感觉上皮中无表达,但是毛细胞损伤后Atoh1表达增高,并可伴有myosinⅦa的共表达。实时定量PCR结果显示小鼠前庭毛细胞再生过程中Hes5下降,Atohl上升,Notch1, Jagged1和Hes1无变化。 结论：Notch信号通路和Atoh1参与了小鼠前庭毛细胞损伤后的自我再生过程。再生的启动时间可能早于过去的观点,Atoh1的升高可能是多条信号通路共同作用的结果。 目的：研究两种不同剂量的链霉素损伤后,小鼠前庭感觉上皮中神经突触、神经纤维和前庭神经节神经元的变化。 方法：通过后半规管将两种不同剂量的链霉素注入小鼠前庭,分别建立小鼠前庭感觉上皮中度和重度损伤模型。神经丝蛋白200抗体免疫荧光染色观察损伤后不同时间点椭圆囊前庭感觉上皮中神经突触和神经纤维的变化；上前庭神经节神经元树脂切片及定量分析,评价神经元的存活情况。 结果：中度损伤和重度损伤后1月,神经盏损伤严重,但是神经纤维存活,上前庭神经节神经元形态正常,密度无明显改变；重度损伤后3月,扁平上皮中无神经盏,上前庭神经节神经元的密度明显下降。 结论：小鼠前庭感觉上皮损伤后,神经支配退化缓慢。这为干细胞移植或人工前庭植入研究提供了有利条件。
[Abstract]:Aim: to study the regeneration of hair cells in vestibular sensory epithelium of mice after two different doses of streptomycin. Methods: two different doses of streptomycin were injected into the vestibular of mice through the posterior semicircular canal of the left ear to establish the model of moderate and severe vestibular sensory epithelium injury. Immunofluorescence staining, scanning electron microscopy and resin sections were performed at different time points after operation to observe the morphological characteristics of sensory epithelium and hair cell regeneration after different degrees of injury. Results: after moderate injury of sensory epithelium of ovale vesicles, hair cells were seriously absent and Sertoli cells were well preserved, and new hair cells with the characteristics of young cilia appeared within 2 weeks after injury, and increased with the prolongation of time. However, the morphology of new hair cells is different from that of normal hair cells, and the number of regenerated hair cells is limited. After severe injury, both hair cells and Sertoli cells were seriously damaged, the vestibular sensory epithelium was replaced by a very thin monolayer flat epithelium, and the ability of self-regeneration of hair cells was extremely weakened when the injury was moderate. Characteristics of hairless cells or Sertoli cells in some cells. Conclusion: the vestibular sensory epithelium of mice has limited ability of self-regeneration after streptomycin injury. Severe injury greatly reduces this ability to regenerate and the vestibular sensory epithelium is replaced by a very thin monolayer flattened epithelium. Aim: to investigate the role of Notch signal pathway factor and Atoh1 in the regeneration of mouse vestibular hair cells. Methods: streptomycin was injected into the vestibule of mice through the posterior semicircular canal pathway to establish the model of moderate vestibular sensory epithelial injury in mice. Then immunofluorescence staining and real-time quantitative PCR were used to detect the expression of Notch signal pathway factor (Notch1, Jagged1, Hes1, Hes5), Atoh1 protein and mRNA in the vestibular sensory epithelium of elliptic sac. Results: the results of immunohistochemistry showed that Jagged1 was expressed in the membrane of Sertoli cells after injury and normal mice, but there was no expression of Atoh1 in vestibular sensory epithelium of normal mice, but the expression of Atoh1 was increased after hair cell injury with co-expression of myosin 鈪，

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