Localization of in the inner ear by non-Rl in situ hybridization

骨桥蛋白(OPN)被认为是一种参与骨化过程的非胶原性骨基质蛋白。本研究用非放射性同位素原位杂交法检测了OPN在大鼠内耳中的表达。在血管纹、螺旋神经节、前庭感觉细胞和前庭暗细胞的边缘细胞中可观察到OPN mRNA的表达。免疫组织化学显示OPN蛋白仅在耳石中表达。OPN mRNA存在于耳蜗区和前庭暗细胞中的原因尚不清楚。另一方面，球囊和椭圆囊的研究结果表明，OPN是大鼠耳石的蛋白质成分之一，前庭毛细胞参与了耳石的形成。

Osteopontin (OPN) is considered to be a non-collagenous bone matrix protein which is involved in the ossification process. However, OPN has recently been observed in ectopic sites such as the kidney and nervous tissues.In the present study, expression of OPN mRNA was examined in the rat inner ear by non-radioisotopic in situ hybridization. Signals of OPN mRNA were observed in the marginal cells of the stria vascularis, spiral ganglions, vestibular sensory cells and vestibular dark cells. OPN protein was detected only in otoliths by immunohistochemistry. The reasons for the presence of OPN mRNA in the cochlea and dark cells of the vestibulum were unclear. On the other hand, findings of the sacculus and utriculus suggest that OPN is one of the protein components of rat otoliths and that vestibular hair cells are involved in the production of otolith.