Functional interaction between Aquaporin-1 (AQP1) and Epithelial Sodium Channel (ENaC). Their role in cellular volume and biomechanic

MARIELA LENZE; RAMIRO GOLDMAN; RICARDO DORR; ROXANA TORIANO

Ciudad Autónoma de Buenos Aires

Congreso; Reunion Conjunta de Sociedades de Biociencias; 2017

Sociedad Argentina de Investigación Clínica

AQP1 and ENaC are both expressed in vascular endothelium. Their functions in this tissue would not be related to their canonical functions. It has been published that ENaC acts as mechano sensor stimulated by a non-genomic action of aldosterone hormone. In addition, we have reported that AQP1 permeability (Pf) is modulated by changes in membrane tension. Our aim was to study a possible functional interaction between AQP1 and ENaC which regulates cellular volume and biomechanic. The experimental model was Xenopus laevis oocyte expressing AQP1, ENaC or both protein by mRNA injection. We measured the osmotic response (OR) and the intracellular pressure (PIC) of these phenotypes challenged by different hypotonic gradients during short times (minutes). Also, these phenotypes were treated with amiloride, an ENaC inhibitor, or aldosterone. In all conditions, intra and extracellular Na+ remains in balance. We estimated the two classical parameters, Pf and water flux (Jw), to describe the OR obtained for the defined phenotypes. Both parameters were significantly greater in the AQP1-ENaC phenotype than the AQP1 one (p