The Migratory Capacity of Human Trophoblastic BeWo Cells: Effects of Aldosterone and the Epithelial Sodium Channel

Abstract

Aldosterone is a key regulator of ENaC channel and stimulates protein methylation on the β-subunit of ENaC. We found that aldosterone (100 nM) promotes cellular migration in a wound healing model in trophoblastic BeWo cells. Here we tested if the positive influence of aldosterone on wound healing is related to the methylation reactions. Cell migration and proliferation were measured in BeWo cells at 6 h, when mitosis is still scarce. Cell migration covered 12.4, 25.3, 19.6 and 45.1 % of the wound when cultivated under control, aldosterone (12 h), 8Br-cAMP and aldosterone plus 8Br-cAMP, respectively. Amiloride blocked the effects of aldosterone alone or in the presence of 8Br-cAMP on wound healing. Wound healing decreased in aldosterone (plus 8Br-cAMP) coexposed with the methylation inhibitor 3-deazaadenosine (3-DZA) (12.9 % reinvasion of the wound). There was an increase in wound healing in aldosterone, 8Br-cAMP and 3-DZA- treated cells, in the presence of AdoMet, a methyl donor, compared to cells in the absence of AdoMet (27.3 and 12.9 % reinvasion of the wound). Cell proliferation assessed with the reagent MTT was not changed in any of these treatments, suggesting that cellular migration is the main factor for the reinvasion of the wound healing. Electrophysiological studies showed an increase in ENaC current in presence of aldosterone. This effect was higher with 8Br-cAMP and there was a decrease when 3-DZA was present. AdoMet treatment partially reversed this phenomenon. We suggest that aldosterone positively influences wound healing in BeWo cells, at least in part through methylation of ENaC.