Differential expression profiles of circulating microRNAs in newborns associated to maternal pregestational overweight and obesity

Abstract

Background: The perinatal environment has a role in the establishment of altered metabolic and inflammatory responses, and could be modulated by microRNAs regulating immune and metabolic processes.

Objective: To analyze the expression profile of four circulating microRNAs and cytokine serum concentrations in neonates born to overweight and obese women.

Methods: Pregnant women were included and grouped by pregestational body mass index (21 with normal weight, 10 overweight and 10 obese women). A peripheral blood sample was obtained from newborn infants and used to determine circulating miRNAs expression and cytokine serum concentrations.

Results: There were significant differences in the expression of three microRNAs between newborns of pregestational obese women and newborns from pregestational normal weight women: miR-155 (p = 0.03), miR-181a (p = 0.02) and miR-221 (p = 0.04). A significant reduction in IL-1β (p = 0.005) expression was also found in newborns of overweight women; although this cytokine was also diminished in newborns of obese women, this was not statistically significant. An association between IL-1β concentrations and miR-146a and miR-221 expression was also observed.

Conclusions: Expression of miR-155, miR-181a and miR-221 differs in infants born to obese women compared with infants born to normal weight women. Changes in microRNA expression could participate in the epigenetic foetal programming of metabolic disorders in children born to obese women.

Keywords: Foetal programming; microRNAs; newborn; obesity; pregnancy.