The expression of aquaporin-4 decreases in preeclamptic placentas

DIETRICH VALERIA; SZPILBARG NATALIA; ABAN CYNTIA; SILBERSTEIN CLAUDIA; ZOTTA ELSA; DAMIANO ALICIA E

Geilo

Congreso; International Federation of Placental Associations Meeting 2011; 2011

International Federation of Placental Associations

The transport of metabolites, ions and water from mother to fetus could take place primarily via transcellular routes. Water transport across hST may be facilitated by aquaporins (AQPs). In some pathological states such as preeclampsia trophoblast invasion of the spiral arteries lead to a failure to establish an adequate uteroplacental blood flow generating a relatively hypoxic trophoblast tissue attenuating considerably. We have first reported that water transport across the preeclamptic placentas was dramatically decreased compared to normal ones and that the expression of AQP3 and AQP9 was altered. Recently, some authors have found that AQP4 expression decreased along gestation in hST and endothelium of normal human placentas. In addition, other authors have reported that brain AQP4 expression changed under hypoxic conditions. OBJECTIVE: The aim of the present work was to study AQP4 in normal and preeclamptic placenta and in a model of ischemia-reperfusion [hypoxia-reoxygenation] type insult. METHODS: AQP4 expression was evaluated by Western blot and immunohistochemistry in normal, preeclamptic placentas and normal placental explants cultured in normoxia, hypoxia, and in hypoxia/reoxygenation conditions. RESULTS: We found that AQP4 was located in the apical membranes of hST and in the endothelium of normal placentas but it was almost undetectable in preeclamptic placentas. When explants were cultured under hypoxic conditions, AQP4 expression increased in both hST and endothelium but decreased after reoxygenation treatment. CONCLUSIONS: Alterations in AQP4 expression as a consequence of the different oxygenation conditions may explain the changes observed in water transport across preeclamptic placentas.