胰岛素样生长因子-1受体在小鼠毛细胞发育过程中的表达

The expression of IGF-1R in hair cells of normal developing mice

目的观察在小鼠耳蜗毛细胞中胰岛素样生长因子(IGF)-1受体(IGF1R)分布和表达情况,探讨其生物学特点。方法制作耳蜗组织铺片,采用荧光免疫组织化学染色方法,激光共聚焦显微镜观察小鼠发育期间(出生后P0-P20)的IGF-1R在耳蜗毛细胞的分布和定位。应用Western印迹及实时PCR法检测新生小鼠毛细胞在出生后不同时期IGF-1R蛋白及mRNA的表达水平。结果耳蜗组织铺片荧光免疫组织化学染色方法显示:IGF-1R在小鼠耳蜗发育过程中在毛细胞均有表达,部位在细胞膜上。随着年龄的增加表达减少。Western印迹及实时PCR显示小鼠耳蜗毛细胞的细胞膜蛋白及mRNA表达水平随着出生年龄增加而逐渐减少。P0组和P4组,P12组,P20组细胞膜蛋白及mRNA的表达水平相比具有明显差异(P<0.05),而P12和P20两组间比较无明显差异(P>0.05)。结论在小鼠耳蜗发育成熟过程中在耳蜗毛细胞IGF-1R均有表达,表达量随着出生年龄增加而减少。推测在内耳细胞发育增殖过程中起重要信号转导作用。

Objective To study the expression and distribution of IGF-1R of the inner ear in normal developing mice, and to elucidate the function and biological characteristics of IGF-1R. Methods The expression and distribution of 1GF-1R of the inner ear during normal developing （P0-P20 after birth） mice was observed by fluorescence immunohistochemistly with laser scanning confocal microscope. IGF- 1R protein and mRNA was examined by Western blot and realtime PCR. Results In the hair cell of cochlea, the mRNA expressions of IGF- 1R detected by in situ hybridization were almost the same as the protein expressions of IGF-I R tested with immunohistochemical methods. The IGF-1R was widely distributed in the cell membrane of hair cells. The protein and mRNA expression of IGF-1R in hair cells and the quantity of expression decreased with aging. The mRNA expression of IGF-1R in group PO was higher than that in group P4, PI2 and P20 （P 〈 0. 01 ） , and there was no significant difference between group P12 and group P20 （P 〉 0. 05 ）. Conclusions There are expressions of IGF-1R in hair cells in normal developing mice. The expressions are related to ages and decrease with aging. IGF-1R may play an important role in signal transduction during inner ear cell proliferation in a paracrine and autocrine manner.