线粒体运输蛋白HUMMR促进低氧环境中大鼠神经元轴突生长

The mitochondrial transport protein HUMMR promotes neuronal axon growth in a hypoxic environment

目的:探讨低氧环境对神经元轴突生长的影响及低氧诱导的线粒体运输调节蛋白(HUMMR)在其中的作用。方法:将来源于SD大鼠的原代培养海马神经元放置在5%低氧培养箱中培养,利用免疫荧光染色方法观察神经元轴突生长情况,通过转染线粒体定位质粒pDsRed2⁃Mito观察神经元中线粒体运输,Western Blot检测HUMMR的表达情况。结果:在5%低氧暴露7 d后,低氧组神经元轴突长度显著高于对照组;神经元中线粒体轴突运输数量和速度都显著增多,尤其轴突逆向运输数量显著多于对照组;Western Blot显示HUMMR蛋白表达升高。结论:低氧环境培养可以促进神经元轴突生长,HUMMR蛋白表达增高,促进线粒体轴突逆向运输功能,可能是促进神经元轴突生长的重要机制之一。

Objective:To investigate the effect of hypoxic environment on neuronal axon growth and the role of hypoxia up⁃regulated mitochondrial movement regulator(HUMMR)protein.Methods:Primary cultured hippocampal neurons derived from SD newborn rats were cultured in a 5%hypoxic incubator.The neuronal axon growth was observed by immunofluorescence straining.The neuronal axonal growth was observed bytransfecting pDsRed2⁃Mito plasmid.The expression of HUMMR in neurons was observed by Western Blot.Results:After 7 days of 5%hypoxic exposure,the axon growth length of neurons in the hypoxic group was significantly higher than that in the control group.The number of mitochondrial and axon transport speed in neurons in the hypoxic group increased significantly,especially the axon reverse transport was significantly higher than that in the control group.Western Blot shows elevated expression of HUMMR protein.Conclusion:Hypoxia environment culture can promote neuronal axon growth,increase HUMMR pro⁃tein expression,promote mitochondrial axon reverse transport function,which may be one of the important mechanisms to promote neuronal axon growth.