六味地黄丸介导RAGE抑制MMP-2/MMP-9对Aβ_(1-40)损伤bEnd.3细胞紧密连接蛋白的影响

Liuwei Dihuang Pills-elicited inhibition of MMP-2/MMP-9 via RAGE on tight junction protein of Aβ_(1-40)-injured bEnd.3 cells

目的探讨六味地黄丸对β淀粉样蛋白1-40(Aβ_(1-40))损伤的小鼠脑微血管内皮细胞(bEnd.3)的保护作用及其机制。方法采用CCK8法检测Aβ_(1-40)和六味地黄丸含药血清(MSLDP)对细胞活性的影响,筛选合适的作用浓度。将bEnd.3细胞分为对照组、Aβ_(1-40)组、MSLDP+Aβ_(1-40)组和MSLDP组,采用Western blot检测低密度脂蛋白相关蛋白1(LRP1)、晚期糖基化终末产物受体(RAGE)、基质金属蛋白酶2(MMP-2)、MMP-9、闭锁小带蛋白-1(ZO-1)、脑源性神经营养因子(BDNF)蛋白表达,免疫荧光检测LRP1、RAGE、ZO-1表达;再将bEnd.3细胞分为对照组、Aβ_(1-40)组、FPS-ZM1(RAGE抑制剂)+Aβ_(1-40)组和FPS-ZM1+Aβ_(1-40)+MSLDP组,Western blot检测RAGE、MMP-9、MMP-2、ZO-1蛋白表达。结果Aβ_(1-40)呈剂量依赖性降低bEnd.3细胞活性(P<0.01),MSLDP对Aβ_(1-40)损伤的细胞活性具有保护作用(P<0.05,P<0.01),因此选择10μmol/L Aβ_(1-40)和10%MSLDP进行后续实验。与对照组比较,Aβ_(1-40)组RAGE、MMP-2、MMP-9蛋白表达升高(P<0.01),LRP1、ZO-1、BDNF蛋白表达降低(P<0.05,P<0.01),并且LRP1、ZO-1荧光强度降低(P<0.01),RAGE荧光增强(P<0.01);与Aβ_(1-40)组比较,MSLDP组RAGE、MMP-2、MMP-9蛋白表达和RAGE荧光强度降低(P<0.05,P<0.01),而LRP1、ZO-1、BDNF蛋白表达和LRP1、ZO-1荧光强度升高(P<0.05,P<0.01)。与Aβ_(1-40)组比较,Aβ_(1-40)+FPS-ZM1组MMP-2、MMP9、RAGE蛋白表达降低(P<0.05,P<0.01),ZO-1蛋白表达升高(P<0.05);Aβ_(1-40)+FPS-ZM1+MSLDP组MMP-2、MMP9、RAGE蛋白表达降低(P<0.01),ZO-1蛋白表达升高(P<0.01),FPS-ZM1和MSLDP联合使用的效果更佳。结论六味地黄丸能够保护Aβ_(1-40)损伤的脑微血管内皮的细胞紧密连接,减轻血脑屏障障碍,保护神经血管单元防治阿尔茨海默病,可能通过调节RAGE途径抑制MMP-2/MMP-9途径实现。

AIM To investigate the protective effects and the mechanism of the Liuwei Dihuang Pills on mouse brain microvascular endothelial(bEnd.3)cells damaged byβ-Amyloid protein1-40(Aβ_(1-40)).METHODS CCK8 method was used to detect the effects of Aβ_(1-40)and medicated serum of Liuwei Dihuang Pills(MSLDP)on cell activity,and to screen the appropriate concentration.bEnd.3 cells of the control group,the Aβ_(1-40)group,the MSLDP+Aβ_(1-40)group and the MSLDP group had their low density lipoprotein-associated protein 1(LRP1),receptor for advanced glycation end products(RAGE),matrix metalloproteinase-2(MMP-2),MMP-9,scaffold protein zonule protein-1(ZO-1)detected by Western blot.bEnd.3 cells assigned into the control group,the Aβ_(1-40)group,the FPS-ZM1(RAGE inhibitor)+Aβ_(1-40)group and the FPS-ZM1+Aβ_(1-40)+MSLDP group had their expressions of RAGE,MMP-9,MMP-2 and ZO-1 detected by Western blot as well.RESULTS The cell activity of bEnd.3,was dose-dependently decreased by Aβ_(1-40)(P<0.01),but was protected by MSLDP(P<0.05,P<0.01).And 10μmol/L Aβ_(1-40)and 10%MSLDP were selected for subsequent experiments.Compared with the control group,the Aβ_(1-40)group displayed increased protein expressions of RAGE,MMP-2 and MMP-9(P<0.01),decreased protein expressions of LRP1,ZO-1 and BDNF(P<0.05,P<0.01),and decreased fluorescence intensities of LRP1 and ZO-1(P<0.01).Compared with the Aβ_(1-40)group,the MSLDP group shared decreased expressions of RAGE,MMP-2,MMP-9 proteins and RAGE fluorescence intensity(P<0.05,P<0.01),and increased expressions of LRP1,ZO-1 and BDNF proteins,and the fluorescence intensity of LRP1 and ZO-1(P<0.05,P<0.01);the Aβ_(1-40)+FPS-ZM1 group displayed decreased protein expressions of MMP-2,MMP9 and RAGE(P<0.05,P<0.01),and increased ZO-1 protein expression(P<0.05);and the Aβ_(1-40)+FPS-ZM1+MSLDP group displayed an even more decreased protein expressions of MMP-2,MMP9 and RAGE(P<0.01),increased ZO-1 protein expression(P<0.01)due to the the combination use of FPS-ZM1 and MSLDP.CONCLUSION Liuwei Dihuang Pills can protect the tight junction of bEnd.3 injured by Aβ_(1-40)and neurovascular units from Alzheimer’s disease by alleviating the dysfunction of the blood-brain barrier via RAGE-mediated MMP-2/MMP-9 pathway inhibition.