Laboratory of Olfactory Transduction, SISSA, International School for Advanced Studies, Via Bonomea 265, Trieste, 34136, Italy.
Dev Neurobiol. 2014 Jul;74(7):657-75. doi: 10.1002/dneu.22159. Epub 2013 Dec 17.
Calcium-activated chloride channels are involved in several physiological processes including olfactory perception. TMEM16A and TMEM16B, members of the transmembrane protein 16 family (TMEM16), are responsible for calcium-activated chloride currents in several cells. Both are present in the olfactory epithelium of adult mice, but little is known about their expression during embryonic development. Using immunohistochemistry we studied their expression in the mouse olfactory epithelium at various stages of prenatal development from embryonic day (E) 12.5 to E18.5 as well as in postnatal mice. At E12.5, TMEM16A immunoreactivity was present at the apical surface of the entire olfactory epithelium, but from E16.5 became restricted to a region near the transition zone with the respiratory epithelium, where localized at the apical part of supporting cells and in their microvilli. In contrast, TMEM16B immunoreactivity was present at E14.5 at the apical surface of the entire olfactory epithelium, increased in subsequent days, and localized to the cilia of mature olfactory sensory neurons. These data suggest different functional roles for TMEM16A and TMEM16B in the developing as well as in the postnatal olfactory epithelium. The presence of TMEM16A at the apical part and in microvilli of supporting cells is consistent with a role in the regulation of the chloride ionic composition of the mucus covering the apical surface of the olfactory epithelium, whereas the localization of TMEM16B to the cilia of mature olfactory sensory neurons is consistent with a role in olfactory signal transduction.
钙激活氯离子通道参与多种生理过程，包括嗅觉感知。跨膜蛋白 16 家族（TMEM16）的成员 TMEM16A 和 TMEM16B 负责几种细胞中的钙激活氯离子电流。这两种蛋白都存在于成年小鼠的嗅上皮中，但在胚胎发育过程中的表达情况知之甚少。我们使用免疫组织化学方法研究了它们在从胚胎期 12.5 天（E）到 18.5 天（E）的产前发育各个阶段以及出生后小鼠的嗅上皮中的表达。在 E12.5 时，TMEM16A 免疫反应性存在于整个嗅上皮的顶表面，但从 E16.5 开始，它仅限于与呼吸上皮过渡区附近的区域，在那里局限于支持细胞的顶部分及其微绒毛。相比之下，TMEM16B 免疫反应性在 E14.5 时存在于整个嗅上皮的顶表面，随后几天增加，并定位于成熟嗅觉感觉神经元的纤毛。这些数据表明 TMEM16A 和 TMEM16B 在发育中和出生后嗅上皮中具有不同的功能作用。TMEM16A 存在于支持细胞的顶部分和微绒毛中，这与调节覆盖嗅上皮顶表面的粘液中的氯离子离子组成的作用一致，而 TMEM16B 定位于成熟嗅觉感觉神经元的纤毛中，与嗅觉信号转导的作用一致。
