人、鼠神经干细胞的生物特性比较

Comparative study on biological property of neural stem cells from embryonic mouse cerebral cortex and fetal hippocampus

目的:比较分析体外人及小鼠神经干细胞原代培养的生长特性。方法:用无血清培养与单细胞克隆技术对人及鼠胚胎脑组织进行分离、培养。借用光镜、免疫组织化学对其鉴定,应用透射电镜对不同生长时期神经干细胞生物学特性进行观察。结果:人和鼠胚胎分离的细胞具有连续分化及克隆能力,克隆球与早期的原始细胞神经上皮干细胞蛋白(nestin)抗原呈阳性。诱导后成熟分化的细胞胶质纤维酸性蛋白(GFAP)及神经丝-200(NF-200)抗原呈阳性。小鼠神经干细胞电镜结果:1周时,细胞发育较为原始,核大胞质少,细胞器不发达,未观察到细胞突起及神经元与星形胶质细胞具备的特征。培养2周后,其电镜结果与1周结果无明显区别。继续培养到4周,见大部分细胞内出现空泡样变性,部分细胞表现出神经元及星形胶质细胞的一些特征。另外在克隆求内观察到类似细胞连接样结构。而人神经干细胞特性与小鼠神经干细胞相似,空泡样变性比小鼠神经干细胞更为明显。人与鼠神经干细胞经诱导分化10d后,见到典型的神经元及星形胶质细胞特征。结论:人及鼠神经干细胞具有很强的增殖能力,生物特性相似。

AIM:To explore the growth property of neural stem cells (NSC) in primary cultu re in vitro from embryonic mouse cerebral cortex and fetal hippocampus comparati vely. METHODS:Serum-free medium and monoclonal technique were used to isolate and c ulture the neural stem cells in vitro obtained from embryomic mouse cerebral cot ex and fetal hippo campus.The biological property of NSCs at different developin g stages was identified and observed with light microscopy, immunohistochemical method and transmission electron microscopy (TEM). RESULTS: The cells from fetal hippocampus and embryonic murine cortex had an a bility of consecutive differentiation and clone.Both neurosphere and native cell s were positive by nestin immunocytochemical staining. Neurofilament-200 (NF-2 00) and glial fibrillary acidic protein (GFAP) antigens were positive in the mat ure cells. The TEM results showed the following. the large nucleus with little p lasm and undeveloped organelle were observed in the NSCs after cell culture for 2 weeks, but cell process and the characteristics of neuron and astrocytes were not found. When the cells from embryonic mouse cortex were cultured for 4 weeks, besides vacuole degeneration of the NSCs, the organellae were rich and develope d, especially, cell process, microtubular microfilament and rough endoplasmic re ticulum (RER) found in some cells. At the same time, the junction-like structur e in monoclone, neurotubules, neurofilaments and glial filaments of some mature cells cultured were observed too. The biological property of NSCs from fetal hip pocampus was similar to that of NSCs from embryonic mouse cortex,while vacuole degeneration was more severe. Ten days after induction and differentiation, the typical morphology of neurons and astrocytes was observed.