Differential expression of miRNAs are associated with the insulin signaling pathway in preeclampsia and gestational hypertension.

Objectives: The objective of this study was to determine microRNAs (miRNAs) expression levels in placental tissue and serum samples from preeclampsia (PE) and gestational hypertensive (GH) patients.

Study Design: Using a targeted qPCR method, the selected miRNAs putatively involved in the PE and GH were examined from normotensive (n = 32), PE (n = 32) and GH (n = 28) in South African women. Western blot analysis of protein expressions of AKT and PI3K was performed in the placental tissue of all three groups.

Results: qPCR results of serum miR-222 expression levels showed a significant decrease in PE compared to GH and normotensive groups. miR-29a expression levels were significantly increased in PE and GH groups compared to normotensives. Serum expression levels of miR-181a in GH showed a significant increase compared to the PE and normotensive groups. Placental tissue expression levels of miR-181a were significantly increased in PE and GH groups compared to normotensives. Western blot results of placental tissue showed a decrease in the expression levels of AKT-serine and threonine in the PE groups compared to the normotensives and a significantly higher expression in the GH groups compared to normotensives. Phosphatidyl-inositol-3 kinase (PI3K) expression levels were significantly decreased in PE and GH groups compared to normotensives.

Conclusion: The present study, interestingly, demonstrates the differential expression of circulating miRNA in GH and a correlation between the expression levels of miRNAs with AKT/PI3K in the insulin signaling pathway, reinforcing the presence of metabolic dysregulation in PE and GH.