Focal adhesion assembly/disassembly and TRPV4 participation in AQP2-dependent renal migration

WHITE A; PIZZONI A; RIVAROLA V; BELTRAMONE N; FORD P; CAPURRO C; DI GIUSTO G

Buenos Aires

Congreso; Reunion Sociedades Biocientificas; 2017

Sociedad Argentina de Fisiologia

We have previously demonstrated that Aquaporin 2 (AQP2) promotesrenal cell migration. It is well known that migration is a processthat requires continuous turnover of focal adhesions (FAs) andit was shown that AQP2 interacts with proteins forming FAs, so theaim of the present work was to study the dynamics of FAs in renalcells expressing AQP2. Moreover, since Ca2+ signaling is implicatedin FAs turnover and results from our laboratory showed a differential activation of the Ca2+ channel TRPV4 influenced by AQP2, we also investigated if TRPV4 participates in the AQP2-enhanced renal cell migration. For experimental procedures two renal cell lines were used: WT-RCCD1 (not expressing AQPs) and AQP2-RCCD1 (transfected with AQP2). Immunofluorescence studies with paxillin were performed in scratched monolayers to visualize FAs. Images were taken with a confocal microscope, deconvolved and processed for making FAs area measurements. Cell migration in presence of TRPV4 agonists 4α-PDD (10 mM) and GSK1016790A (3 nM) was investigated with Wound Healing assay. Images were taken at different times and results were expressed as % of wound closure. Immunofluorescence studies showed punctuated paxillin labeling indicating FAs in the leading edge of migrating RCCD1 cells. These FAs were found to be small in AQP2-RCCD1 (1.80±0.19 mm2 , n=85) than in WT-RCCD1 (5.87±1.04 mm, n=120, p