Cyclic Adenosine Monophosphate Regulation of Aquaporin Gene Expression in Human Amnion Epithelia

Cell membrane aquaporins (AQPs) may con t r i b u t e importantly to the regulation of intramembranous absorption of amniotic fluid. Recently, the authors demonstrated that human amnion AQP3 expression is upregulated by second-messenger cyclic adenosine monophosphate (cAMP). The present study was undertaken to determine the cAMP regulation of other AQP types, specifically AQP1, 8, and 9, in human amnion epithelia in vitro. Human amnion epithelial cell cultures were prepared from amnion of normal-term pregnancy. To investigate the effect of cAMP on AQP expression, primary human amnion cell cultures were incubated for 2, 10, and 20 hours with culture medium containing either 50 µM forskolin, an adenylate cyclase activator that stimulates cellular production of cAMP, or 100 µM SP-cAMP, a cAMP agonist that stimulates protein kinase A. Total RNA was isolated from the cultured cells, and semiquantitative real-time reverse transcription polymerase chain reaction was carried out to determine the relative level of...