New insights in the regulation of placental AQP9: oxygen tension modulates AQP9 expression in human placenta

CASTRO-PARODI MAURICIO; SZPILBARG NATALIA; DIETRICH VALERIA; DI PAOLA MAURICIO; MASKIN BERNARDO; FARINA MARIANA; DAMIANO ALICIA E

Foz de Iguazu

Simposio; V LatinAmerican Symposium on Maternal-Fetal Interaction & Placenta; 2013

Placenta Association of the Americas- Grupo Latinoamericano de placenta

The response of AQP9 to changes in oxygen tension in trophoblast is still unknown. Our aim was to establish whether alterations in oxygen may modulate placental AQP9.We analyzed human AQP9-gene to find putative HIF-1 binding sites. Explants from normal placentas were cultured at different concentrations of oxygen or with CoCl2. AQP9 expression and water uptake were determined. Lipid membrane composition was also studied. Although, fourteen consensus HIF-1 binding sites were found in AQP9-gene, protein expression decreased abruptly when HIF1a was expressed by deprivation of oxygen or COCl2 stabilization. Consequently,water uptake showed an important decrease. In contrast, after reoxygenation, HIF1a was undetectable while AQP9 increased significantly. Interestingly, water phospholipid membrane composition of trophoblast was altered after treatments. Our findings suggest that oxygen may modulate placental AQP9 expression which seems to be independent of water flux.