Differences in miRNAs profile in pregnant women with preeclampsia compared with healthy pregnant women.

Preeclampsia is a hypertensive and multisystemic disorder characterized by mild to severe hypertension during the second half of pregnancy. Circulating microribonucleic acids (miRNAs) have been identified as potential biomarkers for its diagnosis and prognosis. In this study, we compared global miRNA expression profiling in serum samples obtained from pregnant women belonging to three groups: women with severe preeclampsia pregnancies, mild preeclampsia pregnancies, and healthy pregnancies using the NanoString nCounter platform. We found that 26 miRNAs exhibited significant differential expressions between the three groups. Based on predefined selection criteria, miR-604 and miR-423-5p were initially identified as up-regulated, whereas miR-3615, miR-99b-5p, and miR-4443 were down-regulated by NanoString profiling. These candidate miRNAs were subsequently selected for qRT-PCR validation. qRT-PCR analysis confirmed that miR-99b-5p, miR-4443, and miR-604 were consistently down-regulated in both mild and severe preeclampsia compared with healthy pregnancies. miR-3615 demonstrated stage-dependent variation, with significant downregulation in mild preeclampsia and a relative increase in severe cases. Notably, only miR-423-5p exhibited the most pronounced dysregulation, showing slight reduction in mild preeclampsia but a marked up-regulation in severe preeclampsia, consistent with the NanoString results. These findings suggest that miR-423-5p may serve as a potential circulating biomarker associated with disease severity in preeclampsia.