Matsubara Ai, Miyashita Takenori, Mori Terushige, Akiyama Kosuke, Inamoto Ryuhei, Mori Nozomu
Department of Otolaryngology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793, Japan.
Auris Nasus Larynx. 2012 Aug;39(4):361-4. doi: 10.1016/j.anl.2011.07.004. Epub 2011 Aug 25.
Claudins are a family of membrane proteins which localize to tight junctions (TJs). Recent studies have shown that claudins can form pores for ions in the TJs and regulate the permeability of epithelial paracellular ion transport. The endolymphatic sac (ES) is a part of the inner ear, absorbing the endolymphatic fluid. ES dysfunction may result in endolymphatic hydrops. In this study, we focused on the paracellular transport and examined claudin mRNA expression in the ES epithelia.
Total RNA was isolated from whole ES epithelia of rats by laser capture microdissection. RT-PCR was used to evaluate the expression of claudins. The expression of each claudin mRNA in the epithelial cells of rat ES was confirmed by in situ hybridization.
RT-PCR indicated the expression of cldn2, cldn4, cldn6, cldn7, cldn9, cldn11, cldn12, and cldn14. The expression of these claudin mRNAs in the epithelial cells of rat ES was confirmed by in situ hybridization.
We demonstrated mRNA expression of multiple claudins in the rat ES epithelia. These results in the ES epithelia were consistent with a role of claudins in paracellular ion transport.
闭合蛋白是一类定位于紧密连接（TJ）的膜蛋白家族。最近的研究表明，闭合蛋白可在紧密连接中形成离子通道，并调节上皮细胞旁离子转运的通透性。内淋巴囊（ES）是内耳的一部分，负责吸收内淋巴液。内淋巴囊功能障碍可能导致内淋巴积水。在本研究中，我们聚焦于细胞旁转运，并检测了内淋巴囊上皮中闭合蛋白mRNA的表达。
通过激光捕获显微切割技术从大鼠整个内淋巴囊上皮中分离总RNA。采用逆转录聚合酶链反应（RT-PCR）评估闭合蛋白的表达。通过原位杂交证实大鼠内淋巴囊上皮细胞中各闭合蛋白mRNA的表达。
RT-PCR显示了闭合蛋白2、闭合蛋白4、闭合蛋白6、闭合蛋白7、闭合蛋白9、闭合蛋白11、闭合蛋白12和闭合蛋白14的表达。原位杂交证实了这些闭合蛋白mRNA在大鼠内淋巴囊上皮细胞中的表达。
我们证实了大鼠内淋巴囊上皮中多种闭合蛋白的mRNA表达。内淋巴囊上皮中的这些结果与闭合蛋白在细胞旁离子转运中的作用一致。
