To investigate the mechanism of microRNA-383 (miR-383) in regulating soluble fms-like tyrosine kinase-1 (sFlt-1)-mediated phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway in the development of preeclampsia (PE).

A total of 58 pregnant women with PE who delivered at the Department of Obstetrics of Hainan Western Central Hospital from January to December 2022 were selected as the study subjects. They were included into the severe PE group (n=29) and mild PE group (n=29) according to the severity of PE. Twenty-nine healthy pregnant women who were hospitalized and delivered in the same hospital during the same period were enrolled as controls and assigned to control group 1. In parallel, 12 specific pathogen-free (SPF) healthy female pregnant Kunming mice on day 5 of gestation were selected as the study subjects and randomly included in the following groups: model + transfection group 1 [n=3, mice were first treated with tail vein injection of phosphatidylserine (PS)/phosphatidylcholine (PC) emulsion microdroplets to establish a PE-like pathological model, and then administered with the miR-383 mimics transfection complex], model + transfection group 2 (n=3, mice were first treated with tail vein injection of PS/PC emulsion microdroplets to establish a PE-like pathological model, and then administered with the NC agomir mimics transfection complex), model group (n=3, mice were first treated with tail vein injection of PS/PC emulsion microdroplets to establish a PE-like pathological model, and then administered with saline), and control group 2 (n=3, treated with tail vein injection of saline). Serum sFlt-1 protein levels in the three groups of pregnant women and four groups of pregnant mice were measured by enzyme-linked immunosorbent assay (ELISA). The relative expression levels of miR-383 and sFlt-1 mRNA in placental tissues from the three groups of pregnant women and four groups of pregnant mice were determined by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). The relative protein expression levels of PI3K, phosphorylated PI3K (p-PI3K), Akt, and phosphorylated Akt (p-Akt) in placental tissues of four groups of pregnant mice were measured by Western blot. One-way ANOVA method was used to statistically compare the above examination results of the three groups of pregnant women and the four groups of pregnant mice. Further pairwise comparisons were performed using the Student-Newman-Keuls q test. This study was approved by the Ethics Committee of Hainan Western Central Hospital (Approval No. LLKY-2023-10), and written informed consents were obtained from all pregnant women. There were no statistically significant differences in general clinical data, including maternal age, proportion of primiparas and multiparas, and ethnicity, among the three groups of pregnant women (all P>0.05).

① There were statistically significant differences among the three groups of pregnant women in systolic blood pressure, diastolic blood pressure, gestational age at delivery, and 24-hour urinary protein levels (F=214.94, 226.74, 9.40, 449.76; all P<0.001). ② Serum sFlt-1 protein levels in the pregnant women of severe PE group, mild PE group, and control group 1 were (2 941.3±490.1), (2 189.5±455.3), and (1 409.1±318.1) ng/L, respectively, with a statistically significant difference among the three groups (F=93.08, P<0.001). Further pairwise comparisons revealed that serum sFlt-1 protein levels were highest in the severe PE group, followed by the mild PE group and the control group 1, and all the differences were statistically significance (all P<0.001). ③ The relative expression levels of miR-383 and sFlt-1 mRNA in placental tissues of the three groups of pregnant women were compared overall, respectively, and both the differences were statistically significant (P<0.001). Further pairwise comparisons showed that the relative expression levels of miR-383 were lowest in the severe PE group, followed by the mild PE group and the control group 1, while the relative expression levels of sFlt-1 mRNA were highest in the severe PE group, followed by the mild PE group and the control group 1, and all the differences were statistically significant (all P<0.05). ④ Overall comparison of serum sFlt-1 protein levels among the four groups of pregnant mice revealed a statistically significant difference (F=136.49, P<0.001). Further pairwise comparisons showed that the model + transfection group 1 had had significantly lower serum sFlt-1 protein level than the model + transfection group 2 and model group, control group 2 had significantly lower serum sFlt-1 protein levels than the other three groups, and with all differences being statistically significant (all P<0.001). ⑤ Overall comparisons of relative expression levels of placental miR-383 and sFlt-1 mRNA among the four groups of pregnant mice showed statistically significant differences (both P<0.001). Further pairwise comparisons revealed that, for miR-383 expression, model + transfection group 1 had significantly higher levels than the other 3 groups, and the control group 2 had higher level than the model + transfection group 2 and the model group, and all the differences were statistically significant (all P<0.001). For sFlt-1 mRNA expression, the model + transfection group 1 had significantly lower level than the model + transfection group 2 and the model group, and the control group 2 had lower level than the other three groups, and all the differences were statistically significant (all P<0.001). ⑥ Overall comparisons of relative expression levels of placental PI3K, p-PI3K, Akt, and p-Akt protein among the four groups of pregnant mice showed statistically significant differences (all P<0.001). Further pairwise comparisons demonstrated that the model + transfection group 1 had significantly higher levels of these four proteins than the model + transfection group 2 and the model group, the control group 2 had higher levels of these four proteins than the other three groups, and all the differences were statistically significant (all P<0.05).

miR-383 and sFlt-1 play important roles in the pathogenesis of PE in pregnant mice and women. Downregulation of miR-383 leads to upregulation of sFlt-1, which in turn mediates the downregulation of the PI3K/Akt signaling pathway, thereby contributing to the onset and progression of PE in pregnant mice and women.