Expression of microRNA-222 in serum of patients with Alzheimer's disease

The aim of the present study was to determine the association between Alzheimer's disease (AD) and microRNA-222 in the serum of patients with AD. The expression of microRNAs was detected and the results were verified using microarray analysis and reverse transcription-quantitative polymerase chain reaction. The results indicated that there were 35 strips of microRNA in the mild AD group, in which the difference of expression signal was >500 IU/ml. There were 26 strips of microRNA with a difference in expression signal of >500 IU/ml in the mild and moderate AD groups. The downregulation of microRNA-222 in the mild and moderate groups was statistically significant (P<0.01), and the expression of microRNA-222 in the moderate group was significantly lower, compared with that in the mild AD group (P<0.05). It was concluded that microRNA-222 may affect the occurrence and development of AD through a variety of mechanisms, and may serve as a biomarker for the early diagnosis of AD