载脂蛋白e亚型通过erk途径影响轴突生长锥的生长 - 第三军医大学学报.doc

载脂蛋白E亚型通过细胞外信号调节激酶 [摘要] 目的 观察载脂蛋白E（apolipoprotein E，apoE）各个亚型对神经元轴突生长锥的影响并探索其机制。方法 体外培养小鼠皮质神经块，加入重组人类apoE到神经块培养基中，免疫荧光和Western blot检测重组人类apoE能否进入轴突及其生长锥；鬼丙环肽染色生长锥观察重组人类apoE2、3、4对生长锥的影响；加入细胞外信号调节激酶extracellular signal-regulated kinase, ERK)信号通路抑制剂，观察ERK信号通路是否参与apoE亚型对生长锥的影响。结果 免疫荧光和Western blot显示加入重组人类apoE后的神经块轴突及其生长锥中apoE为阳性；加入重组人类apoE2、3、4组的荧光强度分别为50.7±19.4、58.5±15.4、23.4±13.5，其中加入重组人类apoE4的轴突生长锥荧光强度低于加入重组人类apoE2、3的生长锥荧光强度（P0.05）；同时加入重组人类apoE4和ERK信号通路抑制剂的实验组生长锥荧光强度为32.8±13.2，而仅加入重组人类apoE4的实验组生长锥荧光强度为21.9±6.9，实验组生长锥荧光强度高于对照组（P0.05）。结论 重组人类apoE能进入轴突及其生长锥；apoE4能负性影响生长锥生长；阻断ERK信号途径能抑制apoE4对生长锥的负面影响。 [关键词] 神经块；轴突；生长锥；载脂蛋白E；细胞外信号调节激酶 ApoE4 influences the growth cone of neuronal axon through ERK signal pathway. Yin Cheng, Jiang Li, Zhou Shuai, Sun Xiaochuan*（Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China） [Abstract] Objective To observe the effect of apoE subtypes on the growth cones of neuronal axons and explore the possible mechanism. Methods Culturing the cortical explants of mice in vitro, adding the recombinant human apoE into culture medium, the immunofluorescence and western blot were used to detect recombinant human apoE whether entering axons and growth cones; Phalloidin was used to dye the growth cones which were cultured with recombinant human apoE2, 3, 4; ERK inhibitor was added into culture medium to discover ERK pathway whether participating in the process of apoE subtypes influencing the growth cones. Results The data of immunofluorescence and western blot showed the recombinant human apoE was positive in axons and growth cones; the fluorescence intensity of axonal growth cones which cultured by apoE2、3、4 was 50.7±19.4，58.5±15.4，23.4±13.5, the fluorescence intensity of axonal growth cones which cultured by apoE4 was weaker than that of growth cones which cultured by apoE2 or apoE3（P0.05）; the fluorescence intensity of growth cones which cultured by apoE4 and ERK inhibitor was 32.8±13.2,