Analysis of peroxiporin-mediated H2O2 fluxes in HeLa cellular membrane: A therapeutic potential in redox signaling disorders

Once considered merely a byproduct of oxidative respiration with deleterious effects, hydrogen peroxide (H2O2) has now emerged as a pivotal second messenger influencing celular processes by modulating protein function and gene expression. A particularity of the mechanism of action of this molecule resides in its compartmentalized production within cells. To reach its targets, H2O2 must cross cellular membranes aided by members of the family of aquaporin (AQP) channels. In HeLa cells, it has been demonstrated that AQP8 is the unique transporter mediating H2O2 internalization upon an exogenous challenge, despite the presence of abundant mRNA corresponding to AQP3. In this study, we have utilized the genetically encoded H2O2-specific ratiometric HyPer probe stably expressed in HeLa cells cytosol (HeLa HyPerCyto) to explore this paradox by measuring and characterizing H2O2 permeability across both channels. Live imaging analyses revealed that AQP8 is the transporter preferentially used at the highest concentrations tested, while AQP3 appeared to facilitate H2O2 transport at the lower concentrations. These findings deepen into the comprehension of the complex regulation that must be deployed to control a physiological signal which can be potentially harming, providing insights into peroxiporinmediated H2O2 management.