Trophoblast turnover
Abbildung 1: Schematic representation of trophoblast turnover. (A) Normal pregnancy: The final event of cytotrophoblast differentiation, syncytial fusion, results in incorporation of fresh organelles and other cellular material into the syncytium (1). Within the multinucleated syncytiotrophoblast differentiation (2) and subsequently late apoptosis (3) take place. Finally, the late apoptotic material is packed into protrusions of the apical plasma membrane, syncytial knots. These knots are released into the maternal circulation as tightly sealed corpuscles (4). (B) Pre-eclampsia: Enhanced proliferation and syncytial fusion (1) may overwhelm the capacity of the syncytiotrophoblast in terms of differentiation (2) and apoptotic release (3). This may result in a necrotic breakdown of specific sites of the syncytiotrophoblast. If at these sites apoptosis has not yet started, pure necrosis can be observed; if however apoptosis has already lead to first cleavage of proteins, apoptotic material will be necrotically released (aponecrosis). At the same time the syncytiotrophoblast tries to counter balance for the increased input by increasing the release of apoptotic syncytial knots (4). Modified from [15].


Keywords: pregnancy,  Schema,  scheme,  Schwangerschaft,  trophoblast

Term placentas
Abbildung 2: Representative images of chorionic villi from term placentas derived from a normal pregnancy (A) and a pregnancy complicated by late-onset pre-eclampsia (B). In both images staining was performed using a primary antibody against placental-protein 13 (PP13), which is present in the apical membrane of the syncytiotrophoblast. In (A) the normal villous brush border can be seen, which is stained for PP13. In (B) the alterations of the brush border membrane are obvious. Protrusions on the cellular level can be seen (arrows) that may be released into the maternal circulation. Magnification ×900.


Keywords: Plazenta,  pre-eclampsia,  pregnancy,  Präeklampsie,  Schwangerschaft,  term placentas