Expression and function of miR-218-5p in the pathogenesis of postpartum depression

Postpartum depression (PPD) is a prevalent mental health condition following childbirth, currently diagnosed primarily through subjective evaluations, and its underlying biological mechanisms remain poorly understood.

This study evaluated the potential of miR-218-5p as a biomarker for PPD, while further explored its regulatory roles in depressive-like behaviors, inflammatory, and oxidative stress to provide clinical guidance for the precise diagnosis and treatment.

This study enrolled 106 PPD patients and 95 healthy puerperae. A PPD-like model was established in rats via chronic unpredictable mild stress (CUMS), with miR-218-5p overexpression in the experimental group. miR-218-5p levels were quantified via quantitative PCR. Receiver operating characteristic curve and logistic regression assessed miR-218-5p's diagnostic and predictive value. In addition, standard animal behavioral tests evaluated behavioral alterations in the CUMS and miR-218-5p overexpression groups. ELISA measured changes in inflammatory cytokines and oxidative stress markers.

In PPD patients, serum miR-218-5p were significantly lower and inversely related to depressive severity. It showed strong diagnostic accuracy for PPD and served as a standalone biomarker for predicting PPD onset. In CUMS rat model, key behaviors were distinctly altered. In addition, miR-218-5p expression was reduced in rat serum and hippocampus; hippocampal proinflammatory cytokine levels were increased, while antioxidant enzyme activity was lower. Overexpressing miR-218-5p in the model significantly alleviated depressive-like behaviors and reduced hippocampal inflammatory responses and oxidative stress injury. NRAS was a potential target gene of miR-218-5p.

miR-218-5p may act as a promising biomarker for PPD. It can reduce depressive-like symptoms via regulating inflammatory processes and rebalancing oxidative stress through NRAS .