EGFR通过提高mTOR活性增强中枢神经元生长能力

EGFR enhances the growth activity of central neurons by increasing mTOR activity

目的:探寻EGFR对中枢神经元生长活性的影响及机制。方法:构建EGFR过表达(p LEGFP-EGFR)和RNAi干扰(vshRNA-EGFR)的慢病毒载体和质粒,作用于体外培养的神经元。Western-blot检测神经元不同EGFR表达水平下胞内微管蛋白(β-Tubulin)轴突蛋白(Tau)和神经丝蛋白(NF)的表达以及PI3K/Akt/m TOR的活化状态。利用m TOR体外抑制剂Rapamycin进一步观察EGFR的作用途径。结果:EGFR上调的同时观察到神经元中Tau、β-tubulin和NF蛋白表达水平和m TOR活性增加,同时PI3K/AKt通路活性在增强。用100μmol/L的Rapamycins处理24 h后,Tau、β-tubulin和NF表达水平明显下调,同时p-m TOR和p-Akt活性降低,神经元生长活性被抑制。结论:体外EGFR能通过PI3K/Akt信号通路激活,上调m TOR表达,从而促进神经元的生长活性。

Objective： To investigate the effect of EGFR on the growth activity of central neurons. Methods： Neurons were cultured with different EGFR expression levels. Rapamycin was used as an inhibitor of mTOR. Axon protein Tau, neuron proteins β-tubulin and neurofilament were assessed to evaluate the extent of the neurons growth. Expressions of EGFR, p-mTORSer^244s and p-AktSer473 were detected using Western blot for analyzing the underlying mechanisms. Results： Tau, β-tubulin and NF protein were up-regulated when EGFR was overexpressed, and down-regulated after EGFR was blocked. At the same time, the activity of PI3K/Akt pathway show the same trend. The up-regulation effects of growth activity of central neurons by EGFR were blocked by rapamycin（ 100μmol/L treated for 24h）. Conclusion： EGFR could rely on the activation of PI3K/Akt signal pathway, raise the expression of mTOR, finally promote the mentonal growth.