Struckhoff G
Anatomisches Institut, Universität Kiel, Germany.
Int J Dev Neurosci. 1995 Oct;13(6):595-606. doi: 10.1016/0736-5748(95)00040-n.
The glial-limiting membrane at the border of the central nervous system (CNS) consists of glial endfeet covered by a basal lamina. The formation of the glia limitans seems to be controlled by adjacent meninges but only little is known about this interaction. In the present study astrocytes and meningeal cells were investigated in vitro to see if cocultures of these cells can serve as a suitable model for the differentiation of the glial-limiting membrane and can be used to define the conditions under which the glial-limiting membrane develops. The following observations were made in cocultures of meningeal and astrocytic cells of two-day-old rats: (i) epithelioid astrocytes were transformed into stellate cells; (ii) single colonies of proliferating epithelioid astrocytes were generated; (iii) the area around these colonies becomes devoid of meningeal cells, which seem to form a circular border around the astroglial islands; (iv) from the glial colonies long thin glial processes grow towards the surrounding meningeal cells, terminating at the site of contact; (v) in the contact zone between meningeal cells and astrocytes irregular shaped deposits of electron dense material resembling a basal lamina were seen. These observations indicate that indeed a structure resembling a glial-limiting membrane develops in cocultures of meningeal and astrocytic cells. Its formation depends on the balance of growth promoting effects of meningeal cells on astrocytes and growth inhibiting effects of astrocytes on meningeal cells. Both activities can be enriched from conditioned media of pure astrocytic or meningeal cell culture. The proposed model of meningo-astrocytic cocultures may be a helpful instrument for further investigations on the formation of the glia limitans.
中枢神经系统（CNS）边界处的胶质界膜由被基膜覆盖的胶质终足组成。胶质界膜的形成似乎受相邻脑膜的控制，但关于这种相互作用人们了解甚少。在本研究中，对星形胶质细胞和脑膜细胞进行了体外研究，以观察这些细胞的共培养是否可作为胶质界膜分化的合适模型，并用于确定胶质界膜发育的条件。在两天龄大鼠的脑膜细胞和星形胶质细胞共培养中观察到以下情况：（i）上皮样星形胶质细胞转变为星状细胞；（ii）产生了增殖性上皮样星形胶质细胞的单个集落；（iii）这些集落周围的区域没有脑膜细胞，脑膜细胞似乎在星形胶质岛周围形成了一个圆形边界；（iv）从胶质集落伸出的细长胶质突起向周围的脑膜细胞生长，终止于接触部位；（v）在脑膜细胞和星形胶质细胞之间的接触区，可见到不规则形状的电子致密物质沉积，类似于基膜。这些观察结果表明，在脑膜细胞和星形胶质细胞的共培养中确实形成了类似胶质界膜的结构。其形成取决于脑膜细胞对星形胶质细胞的促生长作用与星形胶质细胞对脑膜细胞的生长抑制作用之间的平衡。这两种活性都可以从纯星形胶质细胞或脑膜细胞培养的条件培养基中富集。所提出的脑膜-星形胶质细胞共培养模型可能是进一步研究胶质界膜形成的有用工具。
