Fig 5.

HtrA4 expression under hypoxia and in preeclampsia. (A) Downregulation of HtrA4 expression by hypoxia. BeWo cells were incubated under normoxic or hypoxic conditions. After 72 h of incubation, cells were analyzed by immunoblotting with GCM1, HtrA4, and β-actin Abs, respectively. Phase-contrast images for the morphology of normoxic and hypoxic cells were provided (left). In a separate experiment, cells were subjected to quantitative PCR analysis of the HtrA4 transcript level. (B) Suppression of HtrA4 promoter activity by hypoxia. BeWo cells were transfected with pHtrA4-1kb and incubated under normoxic and hypoxic conditions and subsequently harvested for luciferase assays. (C) Suppression of placental cell invasion by hypoxia. BeWo cells plated in Matrigel-coated chambers were incubated under normoxic or hypoxic condition for invasion analysis. Means and SD from three independent experiments are presented in panels A to C. (D) Decreased HtrA4 expression in preeclamptic placentas. Sections of two normal (N) and two preeclamptic (P) placentas at 38 weeks of gestation were immunostained with HtrA4 Ab. Note that the insets show consecutive sections immunostained with CK7 Ab. Bar, 100 μm.