Las Diferentes tensiones de oxigeno alteraría la expresión de NHE-3 en placenta humana.

DIETRICH VALERIA; SZPILBARG NATALIA; RECA ALEJANDRA; DAMIANO ALICIA E

Buenos Aires

Jornada; XII Jornadas anuales de la Sociedad Argentina de Biología. Buenos Aires, Argentina.; 2010

SAB

It is known that in some pathological states such as preeclampsia (PE) the hypoxic environment during placentation modifies the expression and/or the function of some transport proteins. One of them could be the isoform 3 of the Na+/H+ exchanger (NHE-3) which plays a key role in the maintenance of intercellular pH. Previously, we found that the molecular expression of NHE-3 was decreased in syncytiotrophoblast (hST) from preeclamptic placentas. Up to now, the mechanism that regulates NHE-3 expression remains unclear. The aim of our work was to evaluate if different oxygen tensions alter NHE-3 expression in human placentas.Explants from normal term placenta were incubated in normoxia, hypoxia, and in hypoxia/reoxygenation (H/R). Semiquantitative RT- PCR, Western blot analysis and immunohistochemistry were performed to study NHE-3 expression. We found that the expression of NHE-3 hST is decreased when explants were cultivated under hypoxic treatment. However, H/R partially restored it but less than in normoxia ones. In all cases, NHE-3 was located in the apical membranes and in citoplasmatic regions. We can conclude that hypoxia may alter the expression of the NHE-3 and reoxygenation may partially reverse this effect. Further studies are needed to elucidate if changes in oxygen tension may also modify placental pH homeostasis.