慢性低氧对小鼠脑微血管内皮细胞RAGE和LRP-1表达的影响

目的研究慢性低氧状态下血脑屏障上β淀粉样蛋白（amyloidD，Aβ）转运体——晚期糖基化终产物受体（RAGE）及低密度脂蛋白受体相关蛋白-1（LRP-1）表达的变化。方法将鼠脑微血管内皮细胞（BMVECs）分别进行正常气体培养（正常对照组）以及24h、36h及48h的低氧培养，用RT—PCR法和WesternBlot法分别检测细胞RAGE和LRP-1mRNA和蛋白的表达。结果低氧24h组RAGEmRNA和蛋白表达低于正常对照组（P〈0．05），低氧48h组RAGEmRNA和蛋白表达高于正常对照组（P〈O．05），低氧24h、36h及48h组RAGEmRNA和蛋白表达呈时间依赖性增高（P〈0．05）；低氧各组LRP-1mRNA和蛋白表达较正常对照组降低，呈时间依赖性（P〈0．05）；RAGE／LRP，1mRNA和蛋白表达呈时间依赖性增高（P〈0．05）。结论在慢性低氧状态下，血脑屏障BMVECs表达RAGE上调，LRP-1下调，RAGE／LRP-1比值增高，推测可能由此增加了Ap的净入脑量。

Effect of chronic hypoxia on the expression of RAGE and LRP-1 in mice brain microvascular endothelial cells

Objective To study the effect of chronic hypoxic culture on the expression of amyloid β （A β ） trasport systems receptor for advanced glycation end products （RAGE） and LDL receptor related protein- 1 （LRP- 1） on blood-brain barrier （BBB）. Methods Microvascular endothelial cells（BMVECs） were exposed to chronic hypoxia for 0h（control）,24, 36 and 48 h respectively,the mRNA and protein were detected by RT-PCR and Western Blot. Results Compared to the control, the RAGE mRNA and protein expression were lower at 24 h（P〈0.05） but higher at 48 h（P〈0.05）,and mRNA and protein expression of RAGE increased depend on time under chronic hypoxic condition（P〈0.05）. Compared to the control, mRNA and protein expression of LRP- 1 decreased depend on time under chronic hypoxic condition （P〈0.05）. The ratios of RAGE/LRP-1 mRNA and protein increased depending on time（P〈0.05）.Conclusions Under chronic hypoxic condition, the expression of RAGE increased,but the LRP-1 decreased in BMVECs. The increasing ratios of RAGE/LRP- 1 maybe increase net influx of Aβ into the brain.