title: Assessment of mitochondrial membrane potential in HEI-OC1 and LLC-PK1 cells treated with gentamicin and mitoquinone.
abstract: OBJECTIVE
  To determine the effects of concurrent treatment with gentamicin and the mitochondria-targeted antioxidant mitoquinone (MitoQ; which may prevent gentamicin ototoxicity) on change in the mitochondrial membrane potential (Δψ(m)), a precursor of apoptosis.
  
  
  METHODS
  Prospective and controlled.
  
  
  METHODS
  Academic research laboratory.
  
  
  METHODS
  LLC-PK1 (Lilly Laboratories Culture-Pig Kidney Type 1) and HEI-OC1 (House Ear Institute Organ of Corti 1) cells-renal and auditory cell lines, respectively-were used in this study. Δψ(m) was assessed by flow cytometry through the MitoProbe JC-1 Kit for Flow Cytometry in untreated LLC-PK1 and HEI-OC1 cells and cells exposed to low- (100µM) or high- (2000µM) dose gentamicin for 24 hours, with and without 0.5µM each of MitoQ or idebenone (IDB; an untargeted ubiquinone).
  
  
  RESULTS
  Δψ(m) was not different in untreated LLC-PK1 cells and cells coincubated with low-dose gentamicin and MitoQ or IDB (P > .05). In HEI-OC1 cells, coincubation with low-dose gentamicin and MitoQ decreased Δψ(m) (P = .002). Coincubation of LLC-PK1 cells with high-dose gentamicin and DMSO, MitoQ, or IDB depolarized Δψ(m) (P < .0001), with MitoQ depolarizing the Δψ(m) to a greater extent than that of IDB (P = .03). In contrast, HEI-OC1 cells demonstrated a hyperpolarized Δψ(m) when coincubated with high-dose gentamicin and DMSO, MitoQ, or IDB (P < .001).
  
  
  CONCLUSIONS
  The combination of gentamicin and MitoQ holds the potential to disrupt Δψ(m). This suggests a heightened need to monitor for toxicity in patients receiving both agents.
authors.affiliation: Department of Otolaryngology, University of Florida, Gainesville, FL, USA.
authors.forename: Maria Raye Anne V
authors.initials: MR
authors.lastname: Ng
authors.affiliation: Department of Otolaryngology, University of Florida, Gainesville, FL, USA.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Antonelli
authors.affiliation: Department of Otolaryngology, University of Florida, Gainesville, FL, USA.
authors.forename: Jerin
authors.initials: J
authors.lastname: Joseph
authors.affiliation: Department of Otolaryngology, University of Florida, Gainesville, FL, USA carolyn.ojano-dirain@ent.ufl.edu.
authors.forename: Carolyn Ojano
authors.initials: CO
authors.lastname: Dirain
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D005839:Gentamicins / Q000494:pharmacology*; D006801:Humans; D018374:LLC-PK1 Cells; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects; D011446:Prospective Studies; D013552:Swine; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D005839:Gentamicins; D009943:Organophosphorus Compounds; D014451:Ubiquinone; C429014:mitoquinone
keywords: aminoglycoside; antioxidants; gentamicin; mitochondrial membrane potential; mitoquinone; ototoxicity