POSSIBLE ROLE OF TRPV-1 AND AQPS IN THE REGULATION OF TROPHOBLAST CELL VOLUME

MARTINEZ N ; REPETTI J; ABAN C ; MOYA G ; FARINA M ; DAMIANO

Simposio; VI LatinAmerican Symposium on Maternal-Fetal Interaction & Placenta; 2015

Mammalian cells have homeostatic mechanisms that maintain body-fluid osmolality near 300 mOsm/kg through the intake or excretion of water and salts. This osmoregulation is vital to prevent changes in cell volume that result in irreversible damage. Transient receptor potential vanilloid type-1 (TRPV-1) is a cation channel that mediates Ca2+ influx in response to osmotic stress, acting as a hypertonicity sensor. Recently, we have described TRPV-1 in trophoblast cells. Aquaporins (AQPs) are a family of small integral membrane proteins that facilitate osmotically driven water transport. Although AQP1, AQP3 and AQP9 are highly expressed in trophoblasts during early gestation, their role is still unknown. Objective: To evaluate the contribution of AQPs and TRPV-1 in cell volume regulation of first trimester trophoblast and the consequences on cell viability. Methods: TRPV-1, AQP3 and AQP9 protein expressions were analyzed by Western blot and immunohistochemistry in first trimester human chorionic villous samples (CVS) and in the Swan-71 cell line. The effect of hyperosmolarity on each protein expression was evaluated in Swan-71 cells before and after the inhibition of AQPs with HgCl2. Cell viability was analyzed by MTT assay and cleaved caspase-3 expression. Results: TRPV-1, AQP3 and AQP9 expression was found in CVS and Swan- 71 cells. After exposure to hyperosmolarity, we observed that the expression of the three proteins increased (p