Altered microRNA Expression in Peripheral Blood Mononuclear Cells from Young Patients with Schizophrenia

Schizophrenia (SZ) is a debilitating psychotic disorder of unknown etiology, and the diagnosis is essentially based on clinical symptoms. So it is urgent to find an objective and feasible clinical diagnostic index for SZ. MicroRNA array was performed in peripheral blood mononuclear cells (PBMCs) obtained from young SZ patients and gender-, age-, and ethnicity-matched healthy controls. Then, real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to verify the top 10 microRNAs (miRNAs) with the highest fold change values in 55 SZ patients and 28 healthy controls, and 9 miRNAs demonstrate significant differences in expression levels (P < 0.01). Receiver operating characteristic (ROC) curve analysis showed that the combining area under the ROC curve (AUC) of the nine miRNAs was 0.973 (95 % confidence interval (CI): 0.945-1.000). miRNA target gene prediction and functional annotation analysis showed that there were significant enrichments in several gene ontology (GO) biological process and Kyoto encyclopedia of genes and genomes (KEGG) pathways associated with nervous system and brain functions, suggesting that the differentially expressed miRNAs may be involved in mechanism of SZ. We conclude that altered expression of miRNAs in PMBCs might be involved in young SZ pathogenesis and may serve as noninvasive biomarker for SZ diagnosis.