HYPEROSMOLARITY INDUCES CAVEOLAE INTERNALIZATION IMPAIRING EXTRAVILLOUS TROPHOBLAST DIFFERENTIATION

REPPETTI, JULIETA; DAMIANO, ALICIA E; BELTRAMONE, NATALIA; MEDINA, YOLLYSETH; MARTINEZ, NORA

Ciudad Autonoma de Buenos Aires

Congreso; Reunión Anual de la Sociedad Argentina de Investigaciones Clínicas.; 2020

During placentation, human extravillous trophoblast (EVT) cellsneed to proliferate, migrate, and differentiate correctly to ensure properplacental development. Previously, we reported that caveolaeare required for the proper migration and endovascular differentiationof EVT. Recently, we found that hyperosmolarity alters EVT cellmigration and invasion. However, up to now, the molecular mechanismis unknown. We hypothesized that hyperosmolarity increasescaveolae endocytosis and caveolin-1 (Cav-1) degradation, alteringEVT cell differentiation.Objectives: Our aim was to explore the effect of hyperosmolarityon caveolae microdomains and the impact on the EVT cell differentiation.Methods: The human EVT Swan-71 cell line was cultured in completeDMEM/F-12. 100 mM of sucrose was added to generate thehyperosmolar condition. Cell viability was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay.The localization of caveolae was analyzed by Transmission ElectronMicroscopy (TEM). Cav-1 expression was determined by WB in differentconditions (isoosmolarity or control and hyperosmolarity, withor without MG-132- a proteasome inhibitor- and NH4Cl- a lysosomalinhibitor). Endovascular differentiation was analyzed by the formationof tube-like structures in plates coated with Matrigel®.Results: Cell viability was not affected by the experimental conditions.TEM showed that hyperosmolarity induced the internalizationof caveolae. In addition, hyperosmolarity also increased Cav-1 proteindegradation by lysosomal proteolysis (p