Carr V M, Farbman A I, Colletti L M, Morgan J I
Department of Neurobiology and Physiology, Northwestern University, Evanston, IL 60208-3520.
Neuroscience. 1991;45(2):433-49. doi: 10.1016/0306-4522(91)90239-k.
We have examined adult and embryonic rat olfactory epithelia by immunohistochemical techniques using the monoclonal antibody 1A-6, which was raised against embryonic rat olfactory epithelia. A heretofore unidentified cell type, reactive with the monoclonal antibody 1A-6, was observed scattered within the epithelium. The 1A-6 reactivity of these cells is most intense on the microvilli projecting from the luminal cell surfaces. For several reasons, we believe these cells are not neurons but a distinct subpopulation of supporting cells or some other sort of non-neuronal cells. (1) They have no identifiable axonal process, are not reactive with an antibody against olfactory marker protein, and are not in juxtaposition with trigeminal axons. (2) They survive ablation of the olfactory bulb. (3) Their nuclei lie within the supporting cell layer, and they resemble supporting cells morphologically and in their [3H]thymidine birthdating and turnover characteristics. However, the 1A-6-positive cells fail to react with the general supporting cell-specific monoclonal antibody SUS-1 [see Hempstead J. L. and Morgan J. I. (1983) Brain Res. 188, 289-295] a finding which suggests that they are not typical supporting cells. Immunoreactivity to 1A-6 is developmentally regulated. Immunohistochemical preparations of almost all tissues we examined showed widespread reactivity in the embryo but a much more restricted pattern in the adult. In the olfactory epithelium of the fetus, the luminal surfaces of all cells, including supporting cells and olfactory receptor cells and cilia, are reactive, while in the adult only the non-neuronal cell subpopulation shows this reactivity. We also found that during the reconstitution of olfactory epithelium which occurs in response to olfactory bulbectomy-induced neuronal degeneration, fetal patterns of 1A-6 reactivity are not re-expressed, i.e. the only 1A-6-positive cells are the non-neuronal cells seen in unperturbed adult olfactory epithelium. Preliminary biochemical analyses of membrane fractions from E19 brain and from adult olfactory mucosa indicate that the 1A-6 reactivity is associated with two bands, having molecular weights of 42,000 and 46,000 on Western blots.
我们使用针对胚胎大鼠嗅上皮产生的单克隆抗体1A-6，通过免疫组织化学技术检测了成年和胚胎大鼠的嗅上皮。在整个上皮中散在地观察到一种以前未被识别的细胞类型，它与单克隆抗体1A-6发生反应。这些细胞的1A-6反应性在从管腔细胞表面伸出的微绒毛上最为强烈。出于几个原因，我们认为这些细胞不是神经元，而是支持细胞的一个独特亚群或某种其他类型的非神经元细胞。（1）它们没有可识别的轴突，不与抗嗅觉标记蛋白的抗体发生反应，也不与三叉神经轴突并列。（2）它们在嗅球切除后存活下来。（3）它们的细胞核位于支持细胞层内，在形态上以及在其[3H]胸腺嘧啶核苷出生标记和更新特征方面与支持细胞相似。然而，1A-6阳性细胞不与一般的支持细胞特异性单克隆抗体SUS-1发生反应[见Hempstead J. L.和Morgan J. I.（1983年）《脑研究》188卷，289 - 295页]，这一发现表明它们不是典型的支持细胞。对1A-6的免疫反应性受发育调控。我们检查的几乎所有组织的免疫组织化学制剂在胚胎中显示出广泛的反应性，但在成体中则表现出更为局限的模式。在胎儿的嗅上皮中，所有细胞的管腔表面，包括支持细胞、嗅觉受体细胞和纤毛，都有反应，而在成体中只有非神经元细胞亚群显示出这种反应性。我们还发现，在因嗅球切除诱导的神经元变性而发生的嗅上皮重建过程中，胎儿期的1A-6反应性模式并未重新出现，即唯一的1A-6阳性细胞是在未受干扰的成年嗅上皮中所见的非神经元细胞。对E19脑和成年嗅黏膜的膜组分进行的初步生化分析表明，1A-6反应性与两条带相关，在蛋白质印迹上分子量分别为42,000和46,000。
