Function of newly identified basal lamina structure fractone and regulation of neural stem cell differentiation at subventricular zone

我们分析了大脑中一种新的基底膜状毛细血管结构--Fractone的分子组成。我们还尝试了对存在脑室下区的成体神经干细胞进行鉴定和分离，并探讨了干细胞分化的机制。[1]对新的基底膜样结构进行了分子和细胞分析，用免疫组织化学方法检测了基底膜分子层粘连蛋白和IV型胶原在小鼠脑内的分布。特别是，层粘连蛋白链和IV型胶原链存在于断裂带中，但纤维连接蛋白在那里不表达。此外，脑室下区和脊髓密码区几乎都有裂解带分布，但在第三、四脑室的部分区域未见。发育研究表明，神经干细胞在出生后第7天开始在脑室下层周围表达，然后在出生后第14天仅在脑室外侧部分表达。此外，我们通过免疫电子显微镜分析更准确地识别了神经干细胞的结构。[2]神经干细胞与脑室下区的鉴定和分离我们尝试从成年小鼠脑室下区分离神经干细胞，并允许其在不同条件下进一步分化为神经元和星形胶质细胞。为了建立分化条件，我们制备了富含基质大分子的底物。[3]细胞外基质对干细胞分化的调控我们成功地培养了从侧脑室下区制备的神经球，并建立了进一步分化为神经元和星形胶质细胞的条件。

We analyzed molecular components of the new basement membrane-like structure of capillaries in the brain, fractone. We also tried identification and separation of adult neural stem cells existing subventricular zone, and investigated mechanisms of stem cell differentiation.[1]Molecular and cellular analysis of the new basement membrane like structure fractone.We detected the basement mambrane molecules such as laminin and type IV collagen in the mouse fractone by immunohistochemistry. Especially, several laminin chains and type IV collagen chains were present in the fractone, but fibronectin was not expressed there. Moreover, the fractone was distributed around almost all of subventricular zone in the brain and spinal code but it was not present in some areas of the third and forth ventricle. Developmental studies showed that the fractone started its expression around subventricular zone at postnatal day seven, and then expression pattern was limited to lateral part of ventricle at postnatal day 14. Furthermore, we recognized the fractone structure more precisely using immunoelectron-microscopic analysis.[2]Identification and separation of neural stem cells from subventricular zoneWe tried to separate neural stem cells from adult mouse subventricular zones and allowed them to further differentiate into neurons and astrocytes in various conditions. To set-up differentiation conditions, we prepared substrates rich in matrix macromolecules.[3]Control of stem cell differentiation by extracellular matrixWe successfully culture neurospheres prepared from subventricular zone of the lateral ventricles and set-up conditions to further differentiate into neurons and astrocytes.