Toll样受体4在阿尔茨海默病及血管性痴呆患者外周血单核细胞表达的初步研究

目的:检测Toll样受体4(TLR4)在阿尔茨海默病(AD)及血管性痴呆(VaD)患者外周血单核细胞的表达情况,探讨TLR4在老年期痴呆发病机制中的可能作用。方法:选择临床确诊的AD患者(n=26)、VaD患者(n=31)和正常对照组(n=29)共86例,采用流式细胞术检测3组外周血单核细胞膜上TLR4蛋白阳性表达率及平均荧光强度(MFI)并进行比较分析。结果:外周血单核细胞膜表达TLR4的阳性表达率和MFI AD组和VaD组较对照组明显增高(P0.05)。结论:TLR4作为免疫炎性机制信号通路的关键蛋白,在AD、VaD的发病中均表现为增高,提示炎性机制在AD和VaD的发病中均发挥了作用,TLR4可能不能作为鉴别诊断的潜在生物标志物。

Study on expression of Toll-like receptor 4 in peripheral blood mononuclear cells from patients with Alzheimer disease and vascular dementia

Objective:To investigate the expression of Toll-like receptor 4(TLR4) in peripheral blood mononuclear cells(PBMCs) from patients with Alzheimer disease(AD) and vascular dementia(VaD),and to study the possible role of TLR4 in the pathogenesis of senile dementia.Methods:Clinically diagnosed AD(n=26) and VaD(n=31) patients and healthy controls(n=29) were enrolled in this study.The positive rates(%) and mean fluorescence intensity(MFI) of TLR4 in PBMCs were determined by flow cytometry.Results:The positive rate and MFI of TLR4 in PBMCs in both AD and VaD groups were significantly higher than those in controls(P<0.05).However,no statistically significant difference was found between AD and VaD groups(P>0.05).Conclusions:The expression of TLR4,which was a key protein of immunoinflammatory signal transduction pathway,in PBMCs was elevated in both AD and VaD groups.This suggested that neuroinflammation mechanism was involved in the pathogenesis of AD and VaD,and TLR4 could not be used as a potential biomarker for the differentiation of AD and VaD.