Notch和Wnt信号通路联合对雏鸡听觉毛细胞再生的影响

Effect of combination of Notch and Wnt signaling pathways on the hair cell regeneration after hair cell injury

哺乳类听觉毛细胞(hair cell,HC)损伤后无法再生,鸟类听觉毛细胞损伤后可以再生,研究鸟类毛细胞再生机制将会为研究哺乳动物毛细胞再生提供理论依据.本文选取出生后7d的小鸡作为动物模型,对小鸡基底乳突(basilar papilla,BP)进行体外培养,研究鸟类基底乳突毛细胞再生过程中Notch和Wnt信号通路的作用.研究结果表明:Wnt(Wnt/β-catenin)信号通路与Notch信号通路都对毛细胞的再生作用显著,新生的毛细胞主要来源于支持细胞(supporting cell,SC);抑制Notch信号通路会促进支持细胞转分化变成毛细胞,这个过程会消耗大量的支持细胞,毛细胞的正常功能离不开支持细胞的营养和支撑,支持细胞的过度消耗对长远再生是不可取的;Wnt通路的激动可以促进支持细胞的增殖.本文联合2种信号通路,同时抑制Notch信号通路、激动Wnt信号通路,使大量支持细胞转分化形成毛细胞并不断促进支持细胞的增殖,使毛细胞的再生效果达到最佳状态.

Hair cells in birds or other lower vertebrates,unlike in mammals,have a robust capacity for regeneration,which brings new hope for treatment of mammalian hearing impairment.Chicken inner ears were used for gentamicin treatment(78μmol·L-1,streptomysin for two days).The injured chick basilar papilla(BP)were cultured in Dulbecco's modified Eagle's medium.Licl(7.5 mmol·L-1 in DMSO)was used to activate Wnt signaling and DAPT(50μmol·L-1 in DMSO)to inhibit Notch signaling.It was found that comodulation by Licl and DAPT increased proliferating cells and differentiated cells towards hair cells.Thus,this study provides potential clues also for hair cell restoration in mammals.