Abstract:

Objective To investigate the expression of ATP binding cassette transporter A1(ABCA1) in serum obtained from peripheral blood of the patients with preeclampsia, and to clarify its effects on the injury of endothelial cells and possible mechanisms. Methods 40 cases of mild or severe preeclampsia women and 20 cases of normal pregnancy women were randomly selected, whose period of hospitalization and gestational age had no significant differences.The expression levels of serum ABCA1 and oxidized low-density lipoprotein (OX-LDL) in peripheral vein blood were determined by using ELISA.The primary isolated and cultured umbilical vein endothelial cells (HUVECs) were obtained from the three groups.The function of endothelial cells was tested on the basis of following aspects:monolayer barrier function was evaluated by transferring fluorescently-labeled BSA across the monolayer HUVECs;the cell proliferation was measured by using MTT assay;the levels of secretory nitric oxide(NO)was assayed by nitrate reductase assay. Results The expression levels of ABCA1 protein in serum of the patients in mild or severe preeclampsia groups were significantly lower, whereas the expression levels of OX-LDL and the ratios of OX-LDL/ABCA1 were significantly higher than those in normal pregnancy group(P<0.05).There was obviously negative correlation between the levels of ABCA1 and OX-LDL in the patients with preeclampsia(r=-0.681, P<0.05).Compared with normal pregnancy group, the BSA levels across the monolayer HUVECs of the patients in preeclampsia groups were significantly increased(P<0.05), the proliferation ability of HUVECs was markedly decreased(P<0.05), and the level of secretory NO was significantly reduced(P<0.05).And the more severe the disease, the more significant these changes.The ratio of serum OX-LDL/ABCA1 was positively correlated with the BSA level (r= 0.791, P<0.05), and was negatively correlated with the endothelial cell proliferation level(r=-0.812, P<0.05), and was negatively correlated with the endothelial NO level(r=-0.635, P<0.05) of the patients in preeclampsia groups. Conclusion The expression level of ABCA1 protein in serum of the patients with preeclampsia is decreased which can cause the oxidative stress and OX-LDL/ABCA1 expression imbalance.It is closely related to systemic vascular endothelial cell damage which may be one of the important mechanisms involved in the development of preeclampsia.

Key words: preeclampsia, ATP binding cassette transporter A1, oxidative stress, oxidized low-density lipoprotein, human umbilical vein endothelial cells