EFFECTS OF THE CFTR MODULATORS LUMACAFTOR AND IVACAFTOR ON MITOCHONDRIAL DYNAMICS

CAMILA DIB; TATIANA M. LIMPIAZ DEL VALLE; NADIA NUÑEZ; JAVIER KAMIDA; BIANCA SERRANO SOTO; PILAR PREDASSI; IGLESIAS GONZÁLEZ, PABLO A.; TOMÁS A. SANTA-COLOMA; ANGEL GABRIEL VALDIVIESO

CABA

Congreso; Reunión Anual de la Sociedad Argentina de Fisiología; 2023

SAFIS

Introduction: Mutations in the CFTR gene, responsible for cystic fibrosis (CF), are associated with mitochondrial abnormalities, including changes in mitochondrial dynamics. Previously, we reported increased mitochondrial fission with cAMP stimulation of CFTR activity in IB3-1 (CF) cells. In addition, lumacaftor (VX-809) and ivacaftor (VX-770), the initial CFTR modulators approved forCF therapy, are known to impact CFTR localization and activation. Objectives: This study aims to explore the effects of VX-809 and VX-770 on both mitochondrial morphology and function while considering the hypothesis that CFTR activity may modulate mitochondrial dynamics. Methods: IB3-1 (CF) cells (ΔF508/W1282X) were treated with VX-809 (10 μM) and VX-770 (0.1 μM) for48h. Mitochondrial morphology was analyzed using confocal microscopy with Mitotraker Orange-labeled cells and analyzed with the MiNA plugin in Fiji and Micro-P softwares. Also, MFN1 and DRP1 levels were measured in IB3-1 (CF), S9 (IB3-1 expressing wt-CFTR), and C38 (IB3-1 expressing a truncated functional CFTR) cells. Cellular and mitochondrial ROS levels were quantified by flow cytometry using DCFH-DA and MitoSOX probes, respectively. Mitochondrial membrane potential (Ψm) was measured using TMRE or JC-1 probes by flow cytometry. Results: The combination of VX-809 and VX-770 for 48h increased several indicators of mitochondrial fission (p