Nogo-A蛋白在小鼠中枢神经系统中的表达及其意义

目的　确定髓鞘关联蛋白Nogo -A在小鼠中枢神经系统 (CNS)细胞水平的分布特点 ,探讨Nogo -A蛋白在脊髓损伤后在CNS神经纤维再生中的作用。　方法　用成年C57BL/ 6小鼠的大脑、脊髓、周围组织以及自由落体致伤的脊髓组织作为研究对象 ,采用免疫组织化学方法观察Nogo -A蛋白的表达特点 ;培养鸡胚E12DRG神经元 ,测定在Nogo -A作用下神经元的生长锥萎陷值。　结果　在小鼠CNS中 ,Nogo -A蛋白的表达主要位于少突胶质细胞及其胞突包绕轴突所形成的髓鞘中 ,在周围组织中无表达。脊髓损伤后 ,在损伤灶的周围Nogo -A的表达呈中度增强 ;Nogo -A组的神经元生长锥萎陷率达 70 % ,明显高于空白对照组和载体对照组 ,差异有显著性意义 (P <0 .0 5)。　结论　Nogo -A蛋白在小鼠CNS细胞水平的分布特点对于调控CNS神经纤维轴突的再生可能起重要作用

Expression of Nogo-A protein and its significance in the central nervous system of adult mice

Objective To identify the cellular distribution of a my elin-associated protein (Nogo-A) in the central nervous system (CNS) of mice a nd explore its possible inhibition on the CNS axon regeneration after spinal cor d injury. Methods Brain, spinal cord, peripheral tissues and w eight-dropping injuried spinal cord from the adult C57BL/6 mice were studied. N ogo-A protein expression was localized immunohistochemically. Chick E12DRG neur ons were cultured and growth cone collapse assessed. Results N ogo-A protein expression detected was mainly in the oligodendrocyte cell body a nd the myelinated axons surrounded by cell processes rather than in the peripher al tissues. After spinal cord injury, Nogo-A was up-regulated at a moderate de gree in the area around the lesion. Chick E12 DRG growth cone collapse rate was as high as 70%, significantly higher than that in the blank control and vector control groups with a significant difference ( P <0.05). Conclusions The distribution of Nogo-A protein in the CNS may play an important role in regulating the axon regeneration of the CNS nerve fiber.