MMP-9 and miR-181a-5p in serum and placenta are associated with adverse outcomes of patients with severe preeclampsia and their infants.

This study explored the correlation of MMP-9 with miR-181a-5p in severe preeclampsia (SPE). Placental tissues and serum were collected from 30 pregnant SPE patients (aged 29.42 ± 3.75) and 30 normal pregnant women (aged 27.72 ± 2.21), followed by detecting MMP-9 and miR-181a-5p fold changes using RT-qPCR, and grouped as follows: high expression groups (≥median value): H-MMP-9 and H-miR-181a-5p vs. low expression groups (<median value): L-MMP-9 and L-miR-181a-5p. MMP-9 was weakly expressed (F = 709.99, p < 0.001; F = 670.45, p < 0.001) (serum: 0.41 ± 0.06 (fold changes); placenta: 0.42 ± 0.09 (fold changes)), whereas miR-181a-5p was highly expressed (F = 284.93, p < 0.001; F = 353.78, p < 0.001) (serum: 2.26 ± 0.39; placenta: 2.02 ± 0.29) in SPE patients. MMP-9 was negatively correlated with miR-181a-5p (serum: r = -0.5767, p = 0.0009; placenta: r = -0.5667, p = 0.0011) in SPE patients. MMP-9 showed positive-correlation with gestational week at delivery (r = 0.7625; p < 0.0001) and infant weight (r = 0.4947; p < 0.0001) of SPE patients. miR-181-5p showed negative-correlation (gestational week at delivery: r = -0.5614, p = 0.0012; infant weight: r = -0.4081, p = 0.0252). H-MMP-9 group had lower adverse outcome than L-MMP-9 group (p = 0.0006), and H-miR-181a-5p group had higher adverse outcome than L-miR-181a-5p group (p = 0.0036). In brief, MMP-9 was negatively correlated with miR-181a-5p in serum and placenta of SPE patients. MMP-9 and miR-181a-5p affected gestational week at delivery and infant weight, providing novel targets for SPE treatment.