Expression and localization of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in murine and human placentas.

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is one of the scavenger receptors that recognizes oxidized low-density lipoprotein as a major ligand. The placenta is a major source of prooxidant during pregnancy, and the level of placental oxidative stress increases rapidly at the end of the first trimester and tapers off later in gestation. In our study, we evaluated placental expression of LOX-1 during different gestational stages in mice and humans. We used immunohistochemistry and ISH to identify LOX-1-expressing cells in murine and human placentas. In both species, higher expression of LOX-1 mRNA during early to midgestational stages compared with late gestation-corresponding to the increased oxidative stress in early pregnancy-was shown by real-time RT-PCR. In murine placenta, we showed that LOX-1-expressing cells were fibroblast-like stromal cells in metrial glands and decidua basalis and that they were glycogen trophoblast cells in the junctional and labyrinth zones. In the human, LOX-1 expression was detected in villous cytotrophoblasts in both first trimester and term placentas. These localization patterns of LOX-1 in murine and human placentas suggest the possible involvement of LOX-1 in high oxidative stress conditions of pregnancy.