Alteration of microRNA expression in lymphocytes in patients with first-episode schizophrenia.

Background: The development of schizophrenia is related to a combination of genetic and epigenomic factors. MicroRNAs (miRNAs) play a crucial role in epigenetic processes and are relevant to the onset and progression of schizophrenia. They can regulate target genes during the growth and development of neurons and can be affected by genetic and environmental factors associated with schizophrenia. Although prior studies have found abnormal miRNA expression in schizophrenia, few studies have examined the miRNA level in first-episode schizophrenia (FES). The present study aimed to examine the expression of lymphocyte microRNA (miR-107, miR-181a, miR-181b, miR-223, miR-219, miR-137, miR-125b) in patients with first-episode schizophrenia who had never been treated.

Method: We investigated the expression of miRNAs using the real-time polymerase chain reaction (RT-PCR) technology. The severity of clinical symptoms was assessed using Positive and Negative Syndrome Scale (PANSS). The prognostic value of biomarkers was analyzed using receiver operating characteristic (ROC) curves, and the predictive value of these biomarkers was also compared. Logistic regression analysis was used to assess the relative risk related to microRNA alteration in schizophrenia. Logistic regression analyses were then performed to identify the most significant and sensitive miRNA biomarkers.

Results: Compared with the control group, the patient group exhibited significantly higher levels of expression for six miRNAs (miR-181a, miR-137, miR-223, miR-107, miR-181b, and miR-125b) (P < 0.05). The ROCs indicated that miR-223 exhibited the highest diagnostic value, with an area under the curve being 0.916.

Conclusions: The present study provided some insights into the alteration of miRNA expression, which might improve our understanding of the complex global changes in gene expression in the pathophysiology of schizophrenia. This study identified six miRNAs (miR-223, miR-181a, miR-181b, miR-125b, miR-219, and miR-107) that might facilitate the diagnosis of schizophrenia.