AQP9 expression in human pathological Placentas

DAMIANO, ALICIA E; ZOTTA ELSA; ILLSLEY, NICHOLAS; IBARRA CRISTINA

Sorrento

Conferencia; International Federation of Placenta Associations Meeting 2001; 2001

International Federation of Placenta Associations

Previously we have reported the expression and localization of aquaporin type 9 (AQP9) water channel in the microvillous membranes of the human placental syncytiotrophoblast (hST). In mammals, AQP9 is not only a water channel, but also permits the rapid passage of wide variety of uncharged solutes, including carbamides, polyols, purines and pyrimidines, including many involved in fetoplacental growth and development. It is unknown however, whether the expression of placental AQP9 is altered in pathophysiological conditions of pregnancies, specially those associated with abnormal fetal growth. We therefore examined expression of AQP9 in syncytiotrophoblast microvillous membranes from pregnancies resulting in intrauterine growth retardation(IUGR), diabetic pregnancies (type A and B) and pre-eclamptic pregnancies. Western blot analysis using specific anti AQP9 antibody revealed in all cases two predominant bands at 29 kDa and 37 kDa in syncytial microvillous membranes. Microvillous AQP9 protein expression was unchanged in IUGR or diabetes pregnancies but was increased in placental membranes from preeclamptics. Although the complete etiology of pre-eclampsia has not yet been established, generalized maternal endothelial dysfunction is known to occur. This leads to increased uterine vascular resistance, decrease capacitance and decreased total blood flow to the placenta. It is not clear however whether the changes in AQP9 result from these hemodynamic alterations from more proximal preeclamptic factors.