The cell recognition molecule, cognin, mediates choline acetyltransferase activity in embryonic chick retina.
The cell recognition molecule, cognin, mediates choline acetyltransferase activity in embryonic chick retina.
复制标题
细胞识别分子 cognin 介导胚胎鸡视网膜中的胆碱乙酰转移酶活性。
DOI：
10.1016/0006-8993(92)91191-g
复制
发表时间：
1992
期刊：
影响因子：
2.9
通讯作者：
Hausman,RE
中科院分区：
文献类型：
--
作者：
Sagar,GD;Rao,AS;Ren,Y;Hausman,RE
细胞信号传导和细胞间相互作用在胚胎中枢神经系统的神经元分化中起重要作用。以前的工作(Hausman, r.e., Vivek Sagar， G.D.和Shah， b.h.,Dev。Brain Res., 59(1991) 31-37)表明胚胎鸡视网膜的胆碱能分化依赖于胰岛素和神经元间的相互作用。在这里，我们追求依赖于细胞相互作用的分子本质。已知胚胎鸡视网膜含有几种细胞粘附或识别分子。我们问视网膜认知蛋白，一个50 kDa的细胞表面相关蛋白，是否在控制发育中的鸡视网膜胆碱能分化中起作用。如前所述，胆碱能分化是通过两个标记来衡量的：胆碱乙酰转移酶（ChAT）活性和高亲和力胆碱摄取。我们使用cognin的多克隆抗体来确定阻断cognin介导的细胞相互作用是否会影响正常胚胎中这些胆碱能标记物的增加。我们证明，在早期发育的视网膜神经元培养物中，ChAT活性的正常发育外观受到40%的抑制，但在分化程度更高的视网膜培养物中没有影响。这种抑制对视网膜是选择性的，因为在同样表达ChAT的神经组织如大脑和小脑中没有发现这种抑制。与胰岛素的作用相反，胆碱摄取不受cognin抗体治疗的影响。针对视网膜中存在的另外两种细胞识别分子（Ng-CAM和n -钙粘蛋白）的抗体不会阻止ChAT的正常发育外观。这些结果表明，在发育中的鸡视网膜中，认知素介导的相互作用在控制胆碱能分化的一个方面起着独特的作用。
Cell signaling and cell-cell interactions play an important role in neuronal differentiation in the embryonic CNS. Previous work (Hausman, R.E., Vivek Sagar, G.D. and Shah, B.H.,Dev. Brain Res., 59 (1991) 31–37) had shown that cholinergic differentiation in the embryonic chick retina depends on insulin and neuron-neuron interactions. Here, we pursued the molecular nature of that dependence on cell interactions. The embryonic chick retina is known to contain several cell adhesion or recognition molecules. We asked if retina cognin, a 50 kDa cell surface-associated protein, played a role in controlling cholinergic differentiation in the developing chick retina. As previously, cholinergic differentiation was measured by two markers: choline acetyltransferase (ChAT) activity and high-affinity choline uptake. We used polyclonal antibody to cognin to determine if blocking cognin-mediated cell interactions would affect the normal embryonic increases in these cholinergic markers. We demonstrated a 40% inhibition of the normal developmental appearance of ChAT activity in retina neuronal cultures from early development, but no effect in cultures from more differentiated retina. The inhibition was selective for retina, since it was not seen in neural tissues like cerebrum and cerebellum that also express ChAT. In contrast to the effect of insulin, choline uptake was not affected by treatment with cognin antibody. Antibodies to two other cell recognition molecules present in the retina (Ng-CAM and N-cadherin) did not block the normal developmental appearance of ChAT. These results suggest that cognin-mediated interactions play a unique role in the control of one aspect of cholinergic differentiation in the developing chick retina.