title: GSH monoethyl ester rescues mitochondrial defects in cystic fibrosis models.
abstract: Cystic fibrosis (CF), a multisystem disease caused by CFTR (cystic fibrosis transmembrane conductance regulator) gene mutations, is associated with an abnormal inflammatory response and compromised redox homeostasis in the airways. Recent evidence suggests that dysfunctional CFTR leads to redox imbalance and to mitochondrial reduced glutathione (mtGSH) depletion in CF models. This study was designed to investigate the consequences of mtGSH depletion on mitochondrial function and inflammatory response. mtGSH depletion was confirmed in colonic epithelium of CFTR-null mice and in CFTR-mutated human epithelial cells. GSH uptake experiments performed on isolated mitochondria suggest that mtGSH depletion is not due to a defective GSH transport capacity by CF mitochondria, despite the decreased expression of two mtGSH carriers, oxoglutarate carrier and dicarboxylate carrier. CM-H(2)DCFDA [5 (and 6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester] fluorescence and aconitase activity showed an increase in reactive oxygen species levels in CFTR-defective cells and a pro-oxidative environment within CF mitochondria. The activities of respiratory chain complexes were further examined. Results showed a selective loss of Complex I (CI) function in CF models associated with an altered mitochondrial membrane potential (Δψ(m)). CI analysis showed normal expression but an overoxidation of its NADH-ubiquinone oxidoreductase Fe-S protein 1 subunit. GSH monoethyl ester (GSH-EE) significantly enhanced mtGSH levels in the IB3-1/C38 model and reversed CI inhibition, suggesting that mtGSH depletion is responsible for the loss of CI activity. Furthermore, GSH-EE attenuated Δψ(m) depolarization and restored normal IL-8 secretion by CFTR-defective cells. These studies provide evidence for a critical role of a mtGSH defect in mitochondrial dysfunction and abnormal IL-8 secretion in CF cells and reveal the therapeutic potential of mitochondria-targeted antioxidants in CF.
authors.affiliation: Université Paris Descartes, Faculté de Médecine, site Necker, INSERM U845, Paris, France
authors.forename: Mairead
authors.initials: M
authors.lastname: Kelly-Aubert
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Trudel
authors.forename: Janine
authors.initials: J
authors.lastname: Fritsch
authors.forename: Thao
authors.initials: T
authors.lastname: Nguyen-Khoa
authors.forename: Maryvonne
authors.initials: M
authors.lastname: Baudouin-Legros
authors.forename: Sandra
authors.initials: S
authors.lastname: Moriceau
authors.forename: Ludovic
authors.initials: L
authors.lastname: Jeanson
authors.forename: Fatima
authors.initials: F
authors.lastname: Djouadi
authors.forename: Corine
authors.initials: C
authors.lastname: Matar
authors.forename: Marc
authors.initials: M
authors.lastname: Conti
authors.forename: Mario
authors.initials: M
authors.lastname: Ollero
authors.forename: Franck
authors.initials: F
authors.lastname: Brouillard
authors.forename: Aleksander
authors.initials: A
authors.lastname: Edelman
mesh_terms: D000818:Animals; D002460:Cell Line; D003550:Cystic Fibrosis / Q000188:drug therapy* / Q000378:metabolism; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism; D029382:Dicarboxylic Acid Transporters / Q000235:genetics / Q000378:metabolism; D042967:Electron Transport Complex I / Q000235:genetics / Q000378:metabolism; D005978:Glutathione / Q000031:analogs & derivatives* / Q000494:pharmacology; D016209:Interleukin-8 / Q000378:metabolism; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018181:Mice, Inbred CFTR; D018345:Mice, Knockout; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009154:Mutation; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D020127:Recovery of Function / Q000187:drug effects
chemical_list: C505032:CFTR protein, human; C508606:CXCL8 protein, human; D029382:Dicarboxylic Acid Transporters; D016209:Interleukin-8; D026901:Membrane Transport Proteins; D011837:Radiation-Protective Agents; C021723:oxoglutarate translocator; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; C042431:S-ethyl glutathione; D042967:Electron Transport Complex I; D005978:Glutathione