Letourneau P C, Shattuck T A, Roche F K, Takeichi M, Lemmon V
Department of Cell Biology and Neuroanatomy, University of Minnesota, Minneapolis 55455.
Dev Biol. 1990 Apr;138(2):430-42. doi: 10.1016/0012-1606(90)90209-2.
The role of calcium-dependent adhesion molecules in the migration of nerve growth cones onto the top of Schwann cells was probed by examination of sensory growth cone-Schwann cell interactions in medium containing either 1.0 mM Ca2+ or 0.1 mM Ca2+. In the presence of 1.0 mM Ca2+ growth cones rapidly migrated onto Schwann cells, spread, and remained for extended periods. However, in 0.1 mM Ca2+ growth cones still made frequent contacts with Schwann cells, but migration onto the upper cell surface was much reduced. This contrast in growth cone-Schwann cell interactions could be switched rapidly by changing the Ca2+ concentration of the culture medium. Growth cones of retinal neurons showed similar calcium-dependence in their migration onto Schwann cells. Antibodies to the calcium-dependent adhesion molecule, N-cadherin, also blocked growth cone migration onto Schwann cells, but antibodies to another neuronal adhesion molecule, L1, had no effect on growth cone-Schwann cell interactions. Immunocytochemical staining for N-cadherin and L1 indicated that growth cones and Schwann cells have N-cadherin on their surfaces, while L1 is present only on axons and growth cones. These results provide two kinds of evidence that N-cadherin is important in the initial interactions of growth cones and Schwann cells.
通过检测在含有1.0 mM Ca2+或0.1 mM Ca2+的培养基中感觉神经生长锥与雪旺细胞的相互作用，探究了钙依赖性粘附分子在神经生长锥迁移至雪旺细胞顶部过程中的作用。在1.0 mM Ca2+存在的情况下，生长锥迅速迁移至雪旺细胞上，铺展并长时间停留。然而，在0.1 mM Ca2+条件下，生长锥仍频繁与雪旺细胞接触，但向上细胞表面的迁移则大大减少。通过改变培养基中的Ca2+浓度，生长锥与雪旺细胞相互作用的这种差异可迅速转变。视网膜神经元的生长锥在迁移至雪旺细胞上时显示出类似的钙依赖性。针对钙依赖性粘附分子N-钙粘蛋白的抗体也可阻断生长锥向雪旺细胞的迁移，但针对另一种神经元粘附分子L1的抗体对生长锥与雪旺细胞的相互作用没有影响。对N-钙粘蛋白和L1的免疫细胞化学染色表明，生长锥和雪旺细胞表面有N-钙粘蛋白，而L1仅存在于轴突和生长锥上。这些结果提供了两类证据，表明N-钙粘蛋白在生长锥与雪旺细胞的初始相互作用中起重要作用。
