Expression of
circular RNA (
circRNA), a class of noncoding RNAs that regulates gene expression, is altered in
Alzheimer's disease. This study profiled differentially expressed
circRNAs in peripheral blood mononuclear cells (PBMCs) from five patients with
Alzheimer's disease compared to healthy controls using
circRNA microarrays. We identified a total of 4060 differentially expressed
circRNAs (1990 upregulated and 2070 downregulated) in
Alzheimer's disease patients. Among these
circRNAs, 10 randomly selected
circRNAs were verified using qRT-PCR. The top 10 upregulated and downregulated
circRNAs were used to predict their target
miRNAs. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed that these differentially expressed
circRNAs were strongly associated with
inflammation, metabolism, and immune responses, which are all risk factors for
Alzheimer's disease. The
circRNA-
miRNA-
mRNA network was most involved in the MAPK, mTOR, AMPK, and WNT signaling pathways in
Alzheimer's disease. In conclusion, the current study demonstrated the importance of
circRNAs in
Alzheimer's disease development. Future studies will evaluate some of these
circRNAs as
biomarkers for early disease detection and to develop therapeutic strategies to clinically control
Alzheimer's disease progression.