转化生长因子β1在大鼠胚胎耳蜗中的表达

Expression of transforming growth factor-beta 1 in rat embryohic cochlea

背景:目前人们对耳蜗的发育做了大量的研究工作,但主要集中在病理情况及发育畸形上,而对正常胚胎耳蜗发育过程及相关因子表达的研究较少。目的:观察转化生长因子β1在大鼠胚胎耳蜗中的表达情况。方法:取SD妊娠大鼠56只,从E9-E19逐日将孕鼠断颈,剖腹,迅速取出胚胎,解剖显微镜下修剪内耳标本,经脱水、脱钙、定向石蜡包埋、切片处理。苏木精-伊红染色后光镜下观察内耳形态学演变过程。免疫组织化学SABC法观察转化生长因子β1在胚胎耳蜗的表达。结果与结论:大鼠内耳的发育开始于E8的外胚层增厚区,E9就可观察到听泡及其周围间充质的出现,E9.5听囊及听骨链开始发育,E12.5蜗管始基形成,E18.5耳蜗管发育完成,E16 Corti’s器发育形成,直到出生后内耳的结构和功能才发育完全。转化生长因子β1在E12.5-E19期均有表达,表达情况由弱到强再减弱,E14.5时最强。转化生长因子β1在大鼠耳蜗上皮发育中的表达呈明显的阶段性及组织特异性分布的特点,说明转化生长因子β1可能参与大鼠耳蜗上皮的发育过程。

BACKGROUND： Many researches on the development of cochlea have been made, but mainly depend on the pathological conditions and developmental deformity, while the researches on the development process of normal embryonic cochlea and expression of related factors are rare. OBJECTIVE： To investigate the expression of transforming growth factor 131 in rat embryonic cochlea. METHODS： Fifty-six Sprague Dawley rats were selected and the rats were pregnancy, and the embryos were obtained from the rats, trimmed the inner ear specimens under the anatomical microscope, and then the specimens were treated with dehydration, decalcification, directly paraffin embedding and slicing processing. The morphology evolution of inner cochlea was observed under light microscope after hematoxylin-eosin staining. The expression of transforming growth factor 131 in rat embryonic cochlea was observed by immunohistochemical streptavidin biotin-peroxidase complex method. RESULTS AND CONCLUSION： The development of rat inner ear began in ectoderm thickening area of E8 phase, otocyst and the emergency of the mesenchymal could be seen in E9 phase, otocyst and ossicular chain began to develop in E9.5 phase, formation of cochlear duct anlage could be seen in E12.5 phase, cochlea tube development was completed in E18.5 phase and Corti＇s formation could be seen in E16 phase. The structure and function of the inner ear could be fully developed after birth. The expression of transforming growth factor 131 could be seen in E12.5-E19 phases, and the expression was changed from weak to strong and then weakened further, and strongest in E14.5 phase. This suggested that transforming growth factor 131 may be involved during the development of rat cochlear epithelium.