Role of the Na+/H+ exchanger NHE1 in the AQP2-dependent renal cell migration.

WHITE ALAN; FORD PAULA; DI GIUSTO GISELA; NATALIA BELTRAMONE; CAPURRO CLAUDIA; PIZZONI ALEJANDRO; RIVAROLA VALERIA

Mar del Plata

Congreso; Reunión Anual de la Sociedad Argentina de Fisiología; 2018

Sociedad Argentina de Fisiología

Cell migration is the basis for many physiological and pathophysiologicalprocesses such us wound healing or metastasis. We havepreviously shown that Aquaporin 2 (AQP2) promotes renal cellmigration. Moreover, we have already demonstrated the participationof NHE1 in the increment observed in the % of migration ofAQP2-expressing cells. However, it is well known that NHE1 maycontribute to cell migration in several different ways: affecting cellvolume, regulating intracellular pH (pHi) and controlling cell adhesion,anchoring the cytoskeleton proteins to plasma membrane.The aim of the present work was to perform pHi measurements toevaluate if the activity of NHE1 exchanger inluences the microenvironmentof the lamellipodia in migrating cells. For experimentalprocedures two renal cell lines were used: WT-RCCD1 (not expressingAQPs) and AQP2-RCCD1 (stably transfected with AQP2).Fluorescence videomicroscopy measurements were performed inscratched monolayers: for ratiometric pHi measurements cells wereloaded with the pH-sensitive probe BCECF/AM. Fluorescence datawere acquired every 10s using a charge coupled-device cameraconnected to a computer and the Metaluor acquisition program.Changes in pHi were inferred from the ratio 490/440 of the luorescenceemitted from the lamellipodia of dye-loaded cells localized inthe migrating front. Cells were incubated in control isosmotic solutionor with HOE-694 (1uM) to inhibit NHE1 activity. Results showedthat after incubation with HOE only AQP2-expressing cells present an acidiication of their lamellipodia (ΔControl-HOE; AQP2-RCCD1:0.70±0.24 pH-units, n=40 cells in N=7 experiments, p