Effect of arsenic in epithelial cells with impaired activity of the CFTR

SOTOMAYOR, VERÓNICA; SANTA COLOMA TA,; CLAUZURE, MARIÁNGELES; PEREZ, CARLOS; VALERIA LAURA BERKOWICZ; ANGEL GABRIEL VALDIVIESO

Mar del Plata

Congreso; LXIII Reunión de la Sociedad Argentina de Investigación Clínica (SAIC); 2018

(395) EFFECT OF ARSENIC IN EPITHELIAL CELLS WITHIMPAIRED ACTIVITY OF THE CFTRValeria Laura Berkowicz1, Mariangeles Clauzure1, VerónicaSotomayor1, Angel Gabriel Valdivieso1, Consuelo Mori1, CarlosPerez, Tomás Santa Coloma11Laboratory of Cell and Molecular Biology, Institute for BiomedicalResearch (BIOMED), Pontifical Catholic Universityof Buenos Aires (UCA) and National Scientific and TechnicalResearch Council (CONICET), Buenos Aires, Argentina.Cystic Fibrosis, an inherited disease affecting 1:2500 newborn, ischaracterized by mutations in the CFTR, gene encoding a cAMP-regulatedchloride channel. Little is known about the effects of environmentallyrelevant levels of arsenic on ion channels including theCFTR. The aim of this study was to determine how arsenic affectsmammalian cells with a diminished activity of the CFTR; it is knownthat the metalloid elicits its effect through mitochondrial pathwayswhich, in cystic fibrosis is deeply compromise. IB3-1 (a bronchialcell line derived from a cystic fibrosis patient with a DF508/W1282XCFTR genotype) and S9 (IB3-1 cells transduced with an adeno-associatedviral vector to stably express wt-CFTR) were exposed toAs III (NaAsO2) (0-200 uM) for 2-24 h. Crystal violet assay resultsin S9 and IB3-1 epithelial cells showed increase susceptibility in S9(compare to IB3-1) to As 10-200 uM when exposed for 2-24 h. Similarresponse were found in apoptosis profile measured by Annexin-Vand Propidium iodide apotosis/necrosis assay and flow cytometry(significant differences were assessed by ANOVA and Fisher?s LSDat p =0.01). This might be due to mitochondrial activity impairmentand its involvement in apoptosis. Using synchrotron technology atthe Synchrotron facility in Brazil, we determined speciation in cellsexposed for 2-24 h to As (III) (50-100 uM). This result showed usthat As was mainly found as As+3 form and that might be bindingsulfur, such as As-Glutathione, a well-known detoxifying pathway forAs. Taken together, this results partially explains the importance ofmitochondrial functionality and GSH detoxifying pathway in cells exposedto As III, even at concentrations of As below permitted levelsin drinking water, and for as little as 2 h of exposure. Our next stepis to study the effects of the metalloid on the expression and theactivity of CFTR.