Serum Exosome-Derived miR-139-5p as a Potential Biomarker for Major Depressive Disorder

Background: MicroRNAs (miRs) have been suggested to be biomarkers to inform the diagnosis of major depressive disorder (MDD). We have previously shown that exosomederived miR-139-5p had potential in differentiating between patients with MDD and healthy control (HC) subjects. Materials and Methods: To validate the potential of exosome-derived miR-139-5p as a biomarker for MDD, here we recruited 30 patients with MDD and 30 HC subjects, and used TaqMan probes to detect serum exosomal miR-139-5p levels. Results: The data showed that patients with MDD had significantly increased exosomal miR-139-5p levels when compared with controls. Correlation analysis suggested that sex, age, and body mass index did not significantly affect blood exosomal miR-139-5p levels in the tested subjects. The ROC curve showed that serum-derived miR-139-5p had reasonable performance in discriminating patients with MDD and HC subjects, with a sensitivity of 0.867 and specificity of 0.767, and the AUC was 0.807. Discussion: Taken together, these results demonstrated that patients with MDD were accompanied by significantly increased blood exosomal miR-139-5p levels, and exosomal miR-139-5p is a promising biomarker for the diagnosis of MDD.