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Full-Text Articles in Medicine and Health Sciences
Aminoglycosides Rapidly Inhibit Nad(P)H Metabolism Increasing Reactive Oxygen Species And Cochlear Cell Demise, Danielle E. Desa, Michael G. Nichols, Heather Jensen Smith
Aminoglycosides Rapidly Inhibit Nad(P)H Metabolism Increasing Reactive Oxygen Species And Cochlear Cell Demise, Danielle E. Desa, Michael G. Nichols, Heather Jensen Smith
Journal Articles: Eppley Institute
Despite causing permanent hearing loss by damaging inner ear sensory cells, aminoglycosides (AGs) remain one of the most widely used classes of antibiotics in the world. Although the mechanisms of cochlear sensory cell damage are not fully known, reactive oxygen species (ROS) are clearly implicated. Mitochondrial-specific ROS formation was evaluated in acutely cultured murine cochlear explants exposed to gentamicin (GM), a representative ototoxic AG antibiotic. Superoxide (O2·-) and hydrogen peroxide (H2O2) were measured using MitoSOX Red and Dihydrorhodamine 123, respectively, in sensory and supporting cells. A 1-h GM exposure significantly increased O2·- formation in IHCs and increased H2O2 formation in …
Gentamicin Differentially Alters Cellular Metabolism Of Cochlear Hair Cells As Revealed By Nad(P)H Fluorescence Lifetime Imaging, Lyandysha V. Zholudeva, Kristina G. Ward, Michael G. Nichols, Heather Jensen Smith
Gentamicin Differentially Alters Cellular Metabolism Of Cochlear Hair Cells As Revealed By Nad(P)H Fluorescence Lifetime Imaging, Lyandysha V. Zholudeva, Kristina G. Ward, Michael G. Nichols, Heather Jensen Smith
Journal Articles: Eppley Institute
Aminoglycoside antibiotics are implicated as culprits of hearing loss in more than 120,000 individuals annually. Research has shown that the sensory cells, but not supporting cells, of the cochlea are readily damaged and/or lost after use of such antibiotics. High-frequency outer hair cells (OHCs) show a greater sensitivity to antibiotics than high- and low-frequency inner hair cells (IHCs). We hypothesize that variations in mitochondrial metabolism account for differences in susceptibility. Fluorescence lifetime microscopy was used to quantify changes in NAD(P)H in sensory and supporting cells from explanted murine cochleae exposed to mitochondrial uncouplers, inhibitors, and an ototoxic antibiotic, gentamicin (GM). …
Gentamicin Rapidly Inhibits Mitochondrial Metabolism In High-Frequency Cochlear Outer Hair Cells, Heather Jensen Smith, Richard Hallworth, Michael G. Nichols
Gentamicin Rapidly Inhibits Mitochondrial Metabolism In High-Frequency Cochlear Outer Hair Cells, Heather Jensen Smith, Richard Hallworth, Michael G. Nichols
Journal Articles: Eppley Institute
Aminoglycosides (AG), including gentamicin (GM), are the most frequently used antibiotics in the world and are proposed to cause irreversible cochlear damage and hearing loss (HL) in 1/4 of the patients receiving these life-saving drugs. Akin to the results of AG ototoxicity studies, high-frequency, basal turn outer hair cells (OHCs) preferentially succumb to multiple HL pathologies while inner hair cells (IHCs) are much more resilient. To determine if endogenous differences in IHC and OHC mitochondrial metabolism dictate differential sensitivities to AG-induced HL, IHC- and OHC-specific changes in mitochondrial reduced nicotinamide adenine dinucleotide (NADH) fluorescence during acute (1 h) GM treatment …