Association of microRNA-155, interleukin 17A, and proteinuria in preeclampsia

Background: This study aimed to explore the correlation between microRNA-155 (miR-155), interleukin 17A (IL-17), and late preeclampsia (PE) using biochemical parameters in maternal serum and urine. Methods: Sixty patients with PE were recruited to this study and were divided into 3 groups according to levels of urinary protein: mild urinary protein group (group A); moderate urinary protein group (group B); and severe urinary protein group (group C). All subjects presented with late onset PE (>= 32 weeks). In addition, 20 healthy pregnant women were recruited as a normal group (NP). Maternal serum and urine samples were obtained from all participants and assayed using immunofluorescence, transmission electron and immune electron microscopy, and western blot. Furthermore, placentas were also collected and miR-155 and IL-17 expression was measured using an enzyme-linked immunosorbent assay. Results: Levels of miR-155 and IL-17 expression were found to be increased in PE placentas and serum, compared to the normal group (P<.05). IL-17 levels and podocytes had a positive association in the serum of patients with PE. In addition, over-expression of miR-155 resulted in increased IL-17 production by CD4+ T cells in vitro, and nephrin expression was decreased in podocytes. Furthermore, IL-17 reduced nephrin expression in podocytes and podocyte apoptosis in a dose and time-dependent manner. Conclusion: The results of this study demonstrate a correlation between miR-155 and IL-17 in the formation of proteinuria during late onset PE. Abbreviations: 24U-pro = quantitation of 24-hour urinary protein, CYR61 = cysteine-rich 61, DBP = diastolic pressure, group A = mild urinary protein group, group B = moderate urinary protein group, group C = severe urinary protein group, IL-17 = interleukin 17A, miR-155 = microRNA-155, miRNAs = microRNAs, MPE = mild PE group, NP = a normal group, PE = preeclampsia, SBP = systolic pressure, SPE = severe PE group, TBS = tris-buffered saline, VEGF = vascular endothelial growth factor.