HYPEROSMOLARITY INDUCES CAVEOLAE INTERNALIZATION IMPAIRING EXTRAVILLOUS TROPHOBLAST DIFFERENTIATION

REPPETTI ,JULIETA; MEDINA, YOLLYSETH; BELTRAMONE, NATALIA; DAMIANO, ALICIA E; MARTÍNEZ N,

Congreso; LXV ANNUAL MEETING OF SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA; 2020

During placentation, human extravillous trophoblast (EVT) cells need to proliferate, migrate, and differentiate correctly to ensure proper placental development. Previously, we reported that caveolae are required for the proper migration and endovascular differentiation of EVT. Recently, we found that hyperosmolarity alters EVT cell migration and invasion. However, up to now, the molecular mechanism is unknown. We hypothesized that hyperosmolarity increases caveolae endocytosis and caveolin-1 (Cav-1) degradation, altering EVT cell differentiation.Objectives: Our aim was to explore the effect of hyperosmolarity on caveolae microdomains and the impact on the EVT cell differentiation.Methods: The human EVT Swan-71 cell line was cultured in complete DMEM/F-12. 100 mM of sucrose was added to generate the hyperosmolar 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 Electron Microscopy (TEM). Cav-1 expression was determined by WB in different conditions (isoosmolarity or control and hyperosmolarity, with or without MG-132- a proteasome inhibitor- and NH4Cl- a lysosomal inhibitor). Endovascular differentiation was analyzed by the formation of tube-like structures in plates coated with Matrigel®.Results: Cell viability was not affected by the experimental conditions. TEM showed that hyperosmolarity induced the internalization of caveolae. In addition, hyperosmolarity also increased Cav-1 protein degradation by lysosomal proteolysis (p