Increased Expression of Aquaporin 9 in Trophoblast From Gestational Diabetic Patients

Gestational diabetes mellitus is the most frequent pathophysiological alteration in pregnancy, increasing the incidence of complications in both mother and fetus. The macrosomia that occurs in these fetuses may be related with some changes in nutrient transport mechanism in placenta. The presence of aquaporin 9, an aquaglyceroporin, has previously been demonstrated in placenta. We raised the question whether aquaporin 9 expression may be upregulated in placenta from gestational diabetes, thus providing a faster transport of glycerol and water through placenta. We studied 21 placentas (13 controls and 8 gestational diabetes) from cesarean delivery at term. The expression of aquaporin 9 was analyzed by quantitative PCR, immunoblot, and immunohistochemistry. The median values from quantitative PCR were compared by nonparametric tests for independent samples (Mann-Whitney U-test). We have found that trophoblast from gestational diabetes express higher amount of aquaporin 9, which was found statistically significant (p<0.05). The increase in aquaporin 9 expression was confirmed by immunoblot, and localization in the syncytiotrophoblast was checked by immunohistochemistry. The increase in aquaporin 9 expression in placenta from gestational diabetes may contribute to the higher transport rate in this pathology of pregnancy.