神经干细胞有丝分裂过程中nestin表达变化

在哺乳动物胚胎早期发育过程中 ,中枢神经系统的神经干细胞 ( NSCs)首先通过对称分裂进行自身复制 ,然后通过不对称分裂产生神经元和胶质细胞的前体细胞 ,这些细胞都表达一种中间纤维蛋白 ( IF) -神经巢蛋白 ( nestin)。nestin的表达是暂时的 ,一旦前体细胞分化成终末分化细胞如神经元或胶质细胞 ,nestin则被其他中间纤维蛋白所取代。不同中间纤维在体内不同时期表达的原因和执行的功能还不清楚 ,但可以肯定的是 nestin与 NSCs的多潜能性有关。本实验通过缩时显微成像和免疫组织化学技术观察了 NSCs在对称分裂过程中 nestin的表达变化 ,发现 nestin在前、中、后、末四期的荧光强度表达有不同程度的变化 ,分裂前期与分裂间期相同 ,前中期荧光强度有明显增强 ,到中期荧光强度反而有些下降 ,到末期荧光强度达到最大值 ,胞质分裂后荧光强度逐渐下降。这种波动表达现象将有助于揭示 NSCs维持其多潜能性的奥秘

VARIATION OF NESTIN EXPRESSION DURING NEURAL STEM CELLS MITOSIS

In the vertebrate central nervous system (CNS), neural stem cells (NSCs) in the early cerebral cortical neuroepithelium first divide symmetrically to proliferate, and then divide asymmetrically to generate neuronal and glial progeny. These cells express an intermediate filament (IF) nestin, and once they develop into terminal differentiated cells as neurons or astrocytes, nestin can be replaced by other type IFs. We used time lapse microimaging and immunocytochemistry techniques to detect the process of NSC symmetrical division and found that nestin fluorescence intensity had different degree of enhancement during each mitotic stage of the NSCs, and declined soon after cytokinesis. This phenomenon implies that nestin may have an important role in the symmetric division of multipotential stem cells and help to discover the truth of NSCs multipotency.