Expression of AQP-10, -11 and -12 in the rat stria vascularis

Abstract

Background

Water homeostasis is essential for inner ear function. Several aquaporins (AQPs), which are water transport proteins in the cell or plasma membrane, have been reported in the lateral wall of the rat inner ear (cochlea). However, the presence of AQP-10, -11 and -12 has not been reported in the rat stria vascularis (SV) to date.

Aims/objectives

We have aimed to clarify the expression of AQP-10, -11 and -12 in the cochlea lateral wall.

Materials and methods

Using Wistar rats, we examined the expression of AQP-10, -11 and -12 in the cochlea lateral wall using molecular approaches and immunohistochemistry.

Results

AQP-11 was molecular biologically expressed, but the expression of AQP-10 and -12 was not observed. Immunohistochemically, AQP-11 was diffusely localized in the basal cells and marginal cells of the rat SV but was not expressed at the apical site of marginal cells with double staining. The expression of AQP-10 and -12 was not observed.

Conclusions and significance

Only AQP-11 was expressed in the basal cells and marginal cells, but it was not expressed at the apical site of marginal cells. Based on this study, AQP-11 may not have an important role in water flux between the perilymph and endolymph.

Chinese Abstract

背景: 水稳态对于内耳功能至关重要。 据报道, 几种水通道蛋白 (AQP), 即细胞或质膜中的水转运蛋白, 存在于大鼠内耳(耳蜗)的侧壁中。 然而, 迄今为止, 尚未有大鼠血管纹(SV)中存在 AQP-10、-11 和 -12的报道。

目的: 阐明在耳蜗侧壁中 AQP-10、-11 和 -12的表达。

材料和方法: 我们使用分子法和免疫组织化学法, 检测了Wistar 大鼠耳蜗侧壁 中AQP-10、-11 和 -12 的表达。

结果: AQP-11有分子生物学表达, 但没有观察到AQP-10和-12的表达。 免疫组织化学显示, AQP-11 广泛定位于大鼠 SV的基底细胞和边缘细胞中。但双染色显示, 它不表达于边缘细胞的顶端部位。未观察到 AQP-10 和 -12的表达。

结论及意义: AQP-11仅在基底细胞和边缘细胞中有表达, 但在边缘细胞的顶端部位没有表达。 根据这项研究, AQP-11 可能没有外淋巴和内淋巴之间的水通流的重要功能。

Keywords:

• AQP-10
• AQP-11
• AQP-12
• immunohistochemistry
• molecular biology
• stria vascularis

Acknowledgements

We are greatly indebted to Professor Kenichi Ishibashi for his kind advice on the PCR study of AQP-10.

Disclosure statement

No potential conflict of interest was reported by the author(s).