Expression of aquaporins early in human pregnancy

Abstract Background Aquaporins (AQPs) constitute a family of channel proteins implicated in transmembrane water transport. Thirteen different AQPs (AQP0–12) have been described but their precise biologic function still remains unclear. AQPs 1, 3, 4, 8, and 9 expression has been described in human chorion, amnion and placenta; however, AQP4 is the only that has been identified in the first trimester of human pregnancy. Objective To assess multiplicity of AQPs expression from 10th to 14th week gestation. Population and methods Chorionic villi samples (CVS) collected in pregnant women for prenatal diagnosis were analysed by real time-PCR to assess cDNA expression of AQPs 1, 2, 3, 4, 5, 6, 7, 8, 9, and 11, and compared with AQPs expression in placentas from normal term pregnancies. Results 26 CVS corresponding to 26 pregnant women (age: 32.7 ± 4.5 years; gestational age: 12.4 ± 0.9 weeks) and 10 placental samples corresponding to normal term pregnancies were analysed. In CVS karyotype was normal in 16 cases, trisomy in 6 cases, mosaicism in 1 and unknown in 1. We found high mRNA expression for AQPs 1, 3, 9 and 11, low for AQPs 4, 5, and 8, and non-detectable for AQPs 2, 6, and 7 in chorionic villi. Conclusions This is the first study systematically assessing the expression of a multiplicity of AQPs in chorionic villi samples between 10th and 14th weeks of gestation. High expression of AQP11 has been identified for the first time in early stages of human pregnancy. Chromosomal abnormalities did not alter AQPs' expression.