Dong Y, Sui L, Yamaguchi F, Kamitori K, Hirata Y, Hossain A, Noguchi C, Katagi A, Nishio M, Suzuki A, Lou X, Tokuda M
Department of Cell Physiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan.
Department of Cell Physiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan.
Neuroscience. 2014 Jan 31;258:263-9. doi: 10.1016/j.neuroscience.2013.11.017. Epub 2013 Nov 16.
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor suppressor gene that regulates various cell processes including proliferation, growth, synaptogenesis, neural and glioma stem/progenitor cell renewal. In addition, PTEN can regulate sensory cell proliferation and differentiation of hair bundles in the mammalian cochlea. In this study we use immunofluorescence, Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) to reveal the expression of PTEN in the developing cochlear lateral wall, which is crucial for regulating K(+) homeostasis. Relatively high levels of PTEN are initially expressed in the marginal cells (MCs) of the lateral wall at embryonic day (E) 17.5 when they start to differentiate. Similarly high levels are subsequently expressed in differentiating root cells (RCs) at postnatal day (P) 3 and then in spiral ligament fibrocytes (SLFs) at P 10. In the mature cochlea, PTEN expression is low or undetectable in MCs and SLFs but it remains high in RCs and their processes. The expression pattern for PTEN in the developing lateral wall suggests that it plays a critical role in the differentiation of the cellular pathways that regulate K(+) homeostasis in the cochlea.
10号染色体缺失的磷酸酶及张力蛋白同源物（PTEN）是一种肿瘤抑制基因，可调节包括增殖、生长、突触形成、神经及胶质瘤干/祖细胞更新等多种细胞过程。此外，PTEN可调节哺乳动物耳蜗中感觉细胞的增殖以及毛束的分化。在本研究中，我们使用免疫荧光、蛋白质免疫印迹及逆转录聚合酶链反应（RT-PCR）来揭示PTEN在发育中的耳蜗外侧壁的表达情况，该部位对于调节钾离子稳态至关重要。在胚胎第17.5天，当外侧壁的边缘细胞（MCs）开始分化时，PTEN最初在这些细胞中表达水平相对较高。随后在出生后第3天，分化中的根细胞（RCs）中表达水平同样较高，然后在出生后第10天的螺旋韧带纤维细胞（SLFs）中表达水平较高。在成熟的耳蜗中，PTEN在MCs和SLFs中的表达较低或无法检测到，但在RCs及其突起中仍保持较高水平。PTEN在发育中的外侧壁的表达模式表明，它在调节耳蜗钾离子稳态的细胞途径分化中起关键作用。
