Alzheimer病患者APP及PS1基因表达量的研究

为了检测Alzheimer病（Alzheimer’s disease，AD）患者外周血中淀粉样前体蛋白（Amyloid Precursor Protein, APP）基因及早老素1（Presenilin 1, PS1）基因的表达情况，进而探讨APP及PS1基因的表达与AD的相关性，采用SYBRGreenⅠ的方法对45例AD患者、25例血管性痴呆（vascular dementia, VD）患者及60名正常对照组样本的mRNA进行绝对定量，检测得到APP基因及PS1基因在对照组中的表达水平分别为0.026±0.005 amol/μg cDNA和0.026±0.004 amol/μg cDNA；在AD患者组中的表达量分别为0.044±0.006 amol/μg cDNA和0.051±0.011 amol/μg cDNA；，在VD患者组中的表达水平分别为0.072±0.013 amol/μg cDNA和0.039±0.005 amol/μg cDNA 。经显著性检验，AD患者组APP基因的表达水平上调，t=2.639， P<0.01；PS1基因的表达水平同样呈上调趋势，t=2.173，P<0.05，差异均具有统计学意义。VD患者组APP基因的表达水平上调，t=3.028，P<0.01；PS1基因的表达水平也同样呈上调趋势，t=2.012，P<0.05，均有显著性差异。因此，APP及PS1基因的表达水平的增高并不一定与AD发生特异性关联，而可能与多种导致痴呆的脑部病变发生关联。

Expression Levels of APP and PS1 Genes in Patients with Alzheimer's Disease

The gene expression levels of amyloid precursor protein (APP) and presenilin 1 (PS1) in the peripheral blood samples of patients with Alzheimer's disease(AD) and their association with the disease were studied. The absolute expression levels of APP and PS1 genes were quantified in 45 AD patients, 25 patients with vascular dementia (VD) and 60 healthy controls by real-time quantitative PCR using SYBR Green I. The APP expression levels in healthy controls, AD cases and VD cases are 0.026+/-0.005, 0.044+/-0.006 and 0.072+/-0.013 amol/microg cDNA, respectively; and the PS1 expression levels are 0.026+/-0.004, 0.051+/-0.011 and 0.039+/-0.005 amol/microg cDNA, respectively. Both APP and PS1 expression levels were significantly elevated in AD or in VD cases (APP, AD vs Control, t=2.639, P<0.01, VD vs Control, t=3.028P<0.01; PS1, AD vs Control, t=2.173P<0.05, VD vs Control, t=2.012P<0.05). It seems that elevated APP and PS1 gene expression is associated with dementia but not especially with AD.