The levels of hypoxia-regulated microRNAs in plasma of pregnant women with fetal growth restriction Chun Zhao Placenta 2010

About Placenta Placenta publishes high-quality original articles and invited topical reviews on all aspects of human and animal placentation, and the interactions between the mother, the placenta and fetal development. There are no page charges, and colour plates are free. IF:2.767(2009) The journal publishes 12 issues per year

Introduction Fetal growth restriction (FGR) is biologically characterized as failure of a fetus to reach its growth potential and affecting 3- 10% of births. FGR is a complex disease. Its diagnosis remains difficult. The human placenta can secrete miRNAs and discrete types of miRNA species are found in the plasma of pregnant women, with the plasma level of selected miRNA species altered in a gestational age-dependent manner. The author recently identified that some miRNAs were regulated in human placental trophoblasts exposed to hypoxia. So they hypothesis that the level of these miRNAs is altered in the plasma of women with pregnancies complicated by FGR.

Materials and methods Participants: non-pregnant women(n=11) healthy pregnant women(n=14) women complicated by FGR(n=14) Total RNA isolation: similar to our methods QRT-PCR: SYBR Green PCR

Results

Discussion The change in miRNA species that were quantified in our study suggests an increase in total miRNA levels in the plasma of women with pregnancies complicated by FGR. This increase of circulating miRNAs in FGR was accompanied by a small diminution of miRNAs in placentas from FGR. The negative fold positive fold-change of plasma miRNAs in FGR vs. the negative fold-change of placenta miRNAs in FGR is intriguing. It may reflect process where placental injury in FGR attenuates miRNA biogenesis and increases exosome-dependent or independent release of miRNA to the plasma.

Gains Limits: There were no internal controls in the quantification of plasma miRNAs.