Fgf19对耳蜗毛细胞发育调控机制的研究

The impairment of cochear hair cells (CHCs) is the pathological reason for sensorineural hearing loss. At present, mammalian (including human) CHCs can't regenerate after being impaired, which makes it difficult to cure the disease. As we know birds' (including chicken's) CHCs can regenerate, so it can provide strategy for regulating mammalian CHCs regeneration by researching regeneration mechanism of chicken's CHCs. We found that Fgf19, Bmp4 and CHCA (CHC antigen) expressed in turn and related with strength in CHCs developing region in chicken after summarizing related references, so speculate that Fgf19 and Bmp4 are related to regulating CHCs development, and maybe have a high correlation each other. Supported by the special fund of NSFC in 2012, we completed a preliminary exploration by tissue culture in vitro, found that Fgf19 and Bmp4 have obvious synergistic effect for regulating Cath1 (hair cell marker) expression, while Cath1 expression lowing as Bmp4 being antagonized,and Fgf19 can't rescue it's function. However Bmp4 expression can be significantly strengthened by Fgf19. This project is going to verify the correctness of the theory by using culture and gene interference (RNAi) and over expression in vivo. The results will provide a theoretical basis for treating sensorineural hearing loss by deliverying gene / stem cells to induce CHCs regeneration.

耳蜗毛细胞损伤是感音性耳聋的病理基础, 目前哺乳类(包括人)耳蜗毛细胞损伤后不能再生，使其治疗成为难题。而鸟类（包括鸡）耳蜗毛细胞可再生，对鸡胚耳蜗毛细胞产生机制的研究可为人耳蜗毛细胞再生调控提供策略。我们总结文献发现：鸡胚耳蜗毛细胞发育时，其发育区内依次出现Fgf19、Bmp4、CHCA（耳蜗毛细胞抗原）的表达，且具强度相关性，因此推论：Fgf19和Bmp4与毛细胞发育调控相关，并可能彼此具有相关性。在2012年主任基金资助下，我们采用离体培养完成了初步探索，发现Fgf19 与Bmp4对Cath1（毛细胞标记）表达有明显协同作用；拮抗Bmp4后，Cath1表达减弱，Fgf19未能补救其作用；但Fgf19可使Bmp4表达强度明显增加。因此本项目拟采用活体鸡胚培养/孵化与基因干扰（RNAi）和过表达来验证上述理论的正确性，其结果将为基因/干细胞导入诱导耳蜗毛细胞再生治疗感音性耳聋提供理论指导

耳蜗毛细胞损伤是各种感音性耳聋的病理基础, 目前哺乳类(包括人)耳蜗毛细胞损伤后不能再生，使其治疗成为难题。而鸟类（包括鸡）耳蜗毛细胞则可再生，对鸡胚耳蜗毛细胞产生机制的研究可为人耳蜗毛细胞再生的调控提供策略。我们总结文献发现：鸡胚耳蜗毛细胞发育时，在其发育区内依次出现Fgf19（成纤维细胞生长因19）、Bmp4（骨形态发生蛋白4）、CHCA（耳蜗毛细胞抗原）的表达，且具有强度相关性，因此推论：Fgf19和Bmp4与毛细胞发育调控相关，并可能彼此具有相关性。本项目在活体鸡胚培养的耳囊区加入不同影响因子，通过原位杂交检测耳囊内Bmp4和Cath1（毛细胞的标记基因）的表达情况，发现Fgf19可使Bmp4表达强度明显增加，同时进行了Fgf19过表达腺病毒载体与慢病毒载体、Bmp4过表达慢病毒载体的构建，及三个病毒载体对离体细胞感染效率的评估，为后续实验奠定了基础。