Aquaporin-1 and Caveolin-1 are essential for the proper formation of the placental vasculature

REPPETI J.; SIERRA MATÍAS N; DAMIANO E; MARTÍNEZ N.

Simposio; International Symposium on Reproductive Health: overcoming barriers for research in reproduction; 2021

Introduction: Placental angiogenesis requires proliferation, migration, and differentiation of endothelial cells. There are large numbers of caveolae in the plasma membrane of endothelial cells. Caveolae are lipid domains involved in vesicular trafficking and signal transduction. Caveolin-1 (Cav-1) is the main protein that forms caveolae, and can bind to different membrane proteins such as aquaporins. Aquaporin-1 (AQP1) is a transmembrane water channel that moves water in response to osmotic gradients. Regarding placental macrovascular endothelial cells, we previously demonstrated that AQP1 and Cav-1 are expressed in these cells.Objective: To evaluate the role of AQP1 and caveolae/Cav-1 in the formation of the placental vasculature.Materials and Methods: Macrovasculature cell line EA.hy926 (ATCC® CRL-2922?) was used. Co-localization of Cav-1 with AQP1 was assessed by confocal immunofluorescence. Putative Caveolin-1 binding sites on the amino acid sequence of AQP1 were analyzed by in silico analysis using BioEdit and PyMol programs. Cells were treated with 5mM methyl-β-cyclodextrin (MβCD) to disrupt caveolae, and with tetraethylammonium chloride (TEA) 50μM and 100μM to block AQP1. The efficiency in the blockade of AQPs was evaluated by cell swelling assay. Cell viability was assessed by MTT and cell migration by wound healing assay. Results: In silico analysis showed that AQP1 has a putative binding site for Cav-1. In addition, Cav-1 and AQP1 co-localize in the cell membrane of EA.hy926 cells. Treatment with MβCD to disassembly the caveolar structure significantly reduced cell migration (p