A preliminary analysis of microRNA-21 expression alteration after antipsychotic treatment in patients with schizophrenia

Schizophrenia is a severe and debilitating psychiatric disorder of unknown etiology, and its diagnosis is essentially based on clinical symptoms. Despite growing evidence on the relation of altered expression of miRNAs and schizophrenia, most patients with schizophrenia usually had an extensive antipsychotic treatment history before miRNA expression profile analysis, and the pharmacological effects on miRNA expression are largely unknown. To overcome these impediments, miRNA microarray analysis was performed in peripheral blood mononuclear cells (PBMCs) obtained from patients with schizophrenia who were not on antipsychotic medication and healthy controls. Then, using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), we verified the top 10 miRNAs with the highest fold-change values from microarray analysis in 82 patients with schizophrenia and 43 healthy controls, and nine miRNAs demonstrated significant differences in expression levels. Finally, we compared these nine miRNA profiles before and after antipsychotic treatment. Our results revealed that serum miR-21 expression decreased strikingly in patients after antipsychotic treatment. The change of miR-21 expression was negatively correlated with improvement of positive, general psychopathology, and aggressiveness symptoms. This study preliminarily analyzed the possible changes in circulating miRNAs expression in response to antipsychotic medication for schizophrenia, and the molecular mechanisms of this needs to be further explored.