高原环境对小鼠成体神经发生的影响

Influence of altitude environment on the adult neurogenesis in mice

目的:探索和研究我国青藏高原高海拔生存环境对于小鼠海马齿状回成体神经干细胞增殖和新生细胞分化的影响。方法:健康成年昆明小鼠分为两组,一组为1519 m海拔高度的兰州对照组,另一组为4547 m海拔高度的青藏高原沱沱河高原环境组。运用BrdU腹腔注射和免疫荧光组织化学相结合的方法研究和比较不同环境中齿状回内成体神经干细胞的增殖和新生细胞的分化。结果:高原环境组的BrdU免疫阳性细胞数与低海拔对照组相比减少了40%(P=0.001),而高原环境组小鼠齿状回中的BrdU/Prox-1标记的双阳性细胞在BrdU标记的阳性细胞中的百分比与对照组相比没有显著的差异(P=0.211),并且两组小鼠齿状回中90%以上的BrdU阳性细胞同时也被Prox-1标记。结论:在青藏高原的高海拔低氧环境中,小鼠海马内成体神经干细胞的增殖明显受抑制,然而新生的细胞向颗粒细胞的分化并没有受到明显的影响。

Objective： To investigate the influence of high-altitude living environment in the Qinghai-Tibet Plateau on the proliferation of adult neural stem cells and differentiation of newborn cells in the dentate gyrus in mice.Methods： Healthy adult Kunming mice were divided into two groups： control group,living in Lanzhou（altitude is 1519 m）,and high-altitude environment group,living in Tuotuohe on Qinghai-Tibet Plateau（altitude is 4547 m）.Intraperitoneal BrdU-injection and immunohistochemistry were used to compare the proliferation of adult neural stem cells and differentiation of newborn cells in the dentate gyrus of mice.Results： The BrdU-positive cells in the dentate gyrus of the high-altitude environment group were significantly reduced by 40% compared with those in the control group（P=0.001）.However,the percentage of BrdU/Prox-1 double labeled positive cells in BrdU-positive cells showed no significant difference between two groups（P=0.211）,and more than 90% BrdU-positive cells in dentate gyrus were prox-1-postive.Conclusion： In high-altitude and low oxygen environment of the Qinghai-Tibet Plateau,the proliferation of neural stem cells in the subgranular zone（SGZ） of the dentate gyrus of mice was significantly decreased.However,the newborn cells differentiating into the granule cells was not significantly affected.