Objective: To investigate the role of oxidized low-density lipoprotein (oxLDL) and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in pre-ecalmpsia.
Methods: From June 2007 to January 2008, 73 women with pre-eclampsia who delivered in the Department of Obstetrics, Affiliated Hospital of Qingdao University Medical College, were recruited, including 35 women with mild pre-eclampsia (MPE group) and 38 women with severe pre-eclampsia (SPE group). And 45 healthy pregnant women were taken as control group. Enzyme-linked immunosorbent assay (ELISA) was used to measure the plasma concentrations of oxLDL in these women. Semiquantitative RT-PCR and Western blot were used to investigate the expression of LOX-1 mRNA and protein in placenta. The expression of caspase-3 mRNA in placenta was determined using Semiquantitative RT-PCR.
Results: (1) The plasma concentrations of oxLDL in MPE group (0.42 +/- 0.11) mg/L, SPE group (0.68 +/- 0.12) mg/L, were significantly higher compared with control group (0.35 +/- 0.14) mg/L (P < 0.01) and the concentrations of oxLDL in MPE group were significantly higher compared with SPE group (P < 0.01). (2) The expression of LOX-1 mRNA in placenta of MPE group (0.70 +/- 0.10) and SPE group (0.84 +/- 0.08) were significantly higher than that in control group (0.58 +/- 0.11) (P < 0.01) and the expression of LOX-1 mRNA in MPE group was significantly higher than that of SPE group (P < 0.01). (3) The expression of LOX-1 protein in placenta of MPE group (0.79 +/- 0.15) and SPE group (0.90 +/- 0.12) were significantly higher compared with control group (0.68 +/- 0.11) (P < 0.01), while the expression of LOX-1 protein of MPE group was significantly higher compared with SPE group (P < 0.01). (4) The expression of caspase-3 mRNA in placenta of MPE group (3.82 +/- 0.18) and SPE group (5.39 +/- 0.14) were significantly higher than that in control group (2.19 +/- 0.20) (P < 0.01), and the expression of caspase-3 mRNA in MPE group was significantly higher than that of SPE group (P < 0.01). (5) In pre-eclampsia groups, the levels of LOX-1 mRNA in placenta were positively correlated with the plasma concentrations of ox LDL (r = 0.93, P < 0.05), and caspase-3 mRNA expression were positively correlated with the expression of LOX-1 mRNA in placenta (r = 0.84, P < 0.05).
Conclusion: Increased levels of oxLDL in plasma may induce excess expression of LOX-1 in placenta, which may be involved in the pathophysiological processes of pre-eclampsia.