Gene expression of lipid transporters in peripheral blood mononuclear cells of pregnant women: A longitudinal study

Abstract

PLTP, SR-B1, ABCA1 and ABCG1 transporters mediate the uptake of maternal HDL-cholesterol and its transfer to the foetal circulation. Their placental expressions have already been explored, but less is known about changes in their gene expressions in maternal peripheral blood mononuclear cells (PBMC). The aim of this study was to investigate longitudinal changes in gene expression of PLTP, SRB1, ABCA1 and ABCG1 in maternal PBMCs during healthy pregnancy. Changes in PLTP, SR-B1, ABCA1 and ABCG1 gene expressions, in relation to the maternal smoking status before pregnancy, was examined. Quantification of PLTP, SCARB1, ABCA1 and ABCG1 mRNA was performed using quantitative polymerase chain reaction (qPCR) method in total RNA isolated from PBMCs. In the second trimester (T2), PLTP gene expression was upregulated compared to the first trimester (T1), while in the third trimester (T3) it was significantly downregulated compared to T1 and T2. Gene expression of SRB1, ABCA1 and ABCG1 did not change significantly during the course of healthy pregnancy. A significant negative correlation was observed between the concentration of triglycerides and the ABCA1 and ABCG1 genes in the T1 and T2. During whole pregnancy course, a negative correlation of ABCA1 mRNA with total cholesterol was observed. In T2, ABCA1 mRNA correlated negatively with LDL-cholesterol concentrations. A negative correlation of PLTP mRNA with HDL-cholesterol in T2 was observed. SRB1 gene expression was significantly upregulated in pregnant women who had smoked before pregnancy in T1 and T2. Gene expression of ABCA1 and ABCG1 was significantly upregulated in pregnant women who had smoked before pregnancy during T1. PLTP PBMCs gene expression showed changes throughout healthy pregnancy, which is in line with changes in maternal lipid status. Maternal smoking status before pregnancy significantly affected ABCA1, ABCG1 and SR-B1 PBMCs gene expression during healthy pregnancy, which could affect cholesterol homeostasis in mothers.