Whole-genome microarray and targeted analysis of angiogenesis-regulating gene expression (ENG, FLT1, VEGF, PlGF) in placentas from pre-eclamptic and small-for-gestational-age pregnancies

Objective. To compare the placental pathology associated with pre-eclampsia (PE) and/or fetal growth restriction, the transcriptomes of placental tissues from PE and small-for-gestational-age (SGA) pregnancies were explored. In addition, a targeted analysis of angiogenesis-regulating gene expression was performed. Methods. Whole-genome microarray analysis was performed on placental tissue from gestational age-matched PE (n=10), SGA (n=8) and PE+SGA (n=10) pregnancies. The expression of genes regulating angiogenesis (endoglin (ENG), fms-related tyrosine kinase 1 (FLT1), vascular endothelial growth factor (VEGF) and placental growth factor (PlGF)) was analyzed by quantitative real time reverse transcriptase polymerase chain reaction (qRT-PCR). Results. Microarray analysis did not reveal any significant differences between groups. However, an increased expression of ENG and FLT1 was detected by qRT-PCR in the PE+SGA group. Conclusions. The placental transcriptome did not differ between groups, although an increased anti-angiogenic gene expression in PE+SGA was observed with qRT-PCR analysis. Based on this, we conclude that although microarray technology may represent a powerful tool in generating new hypothesis in complex fields, it may not be sensitive enough to detect subtle changes in gene expression.