Evaluation of MicroRNA-16 and MicroRNA-221 in Serum and Placenta in Gestational Diabetes Mellitus: Correlation with Macrosomia

Abstract

Gestational diabetes mellitus is defined as impaired glucose tolerance diagnosed during pregnancy for the first time and is present in 6-7% of pregnancies with the increase in pregnancy complications (Catalano, 2014). It is one of the most common medical disorders of pregnancy. Women with GDM are at high risk for future type 2 diabetes, 50% of women with GDM subsequently develop type 2 diabetes within 25 years (England et al., 2009;O'Sullivan, 1982). Additionally, maternal diabetes during pregnancy exposes the fetus to hyperglycemia and high insulin levels, which might be related to increased risk of childhood and adult obesity; type 2 diabetes and GDM at childbearing ages (Dabelea et al., 2000).There are series of metabolic changes that occur during normal pregnancy, with a progressive increase in insulin resistance mainly due to placental hormones production (growth hormone, progesterone, placental lactogen, and corticotrophin) important for fetal nutrition. Gestational diabetes develops in women whose insulin production is insufficient to counteract increasing insulin resistance (Catalano, 2014) that has been correlated with increasing of maternal G ESTATIONAL diabetes mellitus (GDM) is associated with short and long-term complications for pregnant women and their coming offspring. MicroRNAs are small noncoding RNA molecules that regulate gene expression. This study aimed to investigate the potential expression of microRNA-16 and 221 in maternal serum and their mirror expression in the placenta in GDM and their correlation with severity of GDM and Macrosomia.This study was conducted on twenty pregnant women with GDM and other twenty healthy pregnant women who served as a control group. GDM group was further subdivided into severe and mild subgroups according to the levels of fasting and postprandial 2 hours glucose levels. MicroRNA-16 and microRNA-221 were estimated by quantitative real time polymerase chain reaction (qRT-PCR). Results revealed that microRNA-16 levels in serum and placental tissue were significantly higher in the GDM group than the control group, with high significant increase in severe GDM than in mild GDM subgroup. Significant decreases in the levels of microRNA-221 were detected in both serum and placenta in GDM group versus the control group. In GDM group, there was a direct high significant correlation of microRNA-16 in serum and placenta with fetal macrosomia, but there was no correlation of microRNA-221 in serum with fetal macrosomia.A significant increase of microRNA-16 in the severe GDM group than in the mild GDM group was observed and it could be concluded that microRNA-16 may be the noncoding RNA at the molecular level that affected the severity of GDM in mothers and the macrosomia of their offspring.