Screening of Alzheimer's disease-associated gene expression changes through peripheral blood monocytes extracted gene microarray analysis in patients with Alzheimer′s disease

Objective To screen the amyloid protein-β(Aβ)degradation-associated genes through peripheral blood monocytes(PBMC)-extracted gene microarray analysis in patients with Alzheimer′s disease(AD). Methods PBMC were isolated from blood of elderly AD patients versus age-matched healthy individuals(control). The cDNA(mRNAs)were analyzed using gene microarray.And real-time quantitative polymerase chain reaction detection and enzyme activity analysis were used to verify the primary outcome of gene chip. Results The expression of cathepsin D mRNA in peripheral blood monocytes was 104.70±15.96 in AD patients as compared with the control group 49.86±5.19, and the activity of cathepsin D was(22 620±1 389)RFU in AD versus(32 210±2 284)RFU in control(both P<0.05). Conclusions The results suggest that the decreased levels of cathepsin D could be the stage markers related to the pathophysiology of AD process.Based on the microarray data, we select cathepsin D genes for further study. Key words: Alzheimer disease; Monocytes; Amyloid beta-protein; Oligonucleotide array sequence analysis