TY - JOUR
T1 - Aminoglycosides rapidly inhibit NAD(P)H metabolism increasing reactive oxygen species and cochlear cell demise
AU - Desa, Danielle E.
AU - Nichols, Michael G.
AU - Smith, Heather Jensen
N1 - Funding Information:
Research reported in this publication was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences; Award No. P20GM103471 (Imaging Core and HJS Pilot Project Grant) and the National Center for Research Resources; Award No. G20RR024001, of the National Institutes of Health. DD was supported by Dr. Randolph M. and Teresa Kolars Ferlic and Clare Boothe Luce undergraduate research scholarships. MN was supported by the National Institute of General Medical Sciences; Award Nos. R15GM085776 and 5P20GM103427. This research was also supported by the National Institute on Deafness and Other Communication Disorders; Award No. RO3DC012109, to HJS. Imaging was conducted at the Creighton University Integrated Biomedical Imaging Facility. The contents are the sole responsibility of the authors and do not necessarily represent the official views of NIGMS, NCRR, or NIH.
Publisher Copyright:
© © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - 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 (O 2 ·-) and hydrogen peroxide (H 2 O 2) were measured using MitoSOX Red and Dihydrorhodamine 123, respectively, in sensory and supporting cells. A 1-h GM exposure significantly increased O 2 ·-formation in IHCs and increased H 2 O 2 formation in all cell types. At the same time point, GM significantly increased manganese superoxide dismutase (MnSOD) levels while significantly decreasing copper/zinc superoxide dismutase (CuZnSOD) in cochlear sensory cells. This suggests (1) a rapid conversion of highly reactive O 2 ·-to H 2 O 2 during the acute stage of ototoxic antibiotic exposure and (2) that the endogenous antioxidant system is significantly altered by AGs. Fluorescence intensity-based measurements of reduced nicotinamide adenine dinucleotide (phosphate) [NAD(P)H] and mitochondrial membrane potential were measured to determine if increases in GM-induced ROS production were correlated with changes in mitochondrial metabolism. This project provides a basis for understanding the mechanisms of mitochondrial ROS production in cochlear cells exposed to ototoxic antibiotics. Understanding the nature of ototoxic antibiotic-induced changes in mitochondrial metabolism is critical for developing hearing loss treatment and prevention strategies.
AB - 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 (O 2 ·-) and hydrogen peroxide (H 2 O 2) were measured using MitoSOX Red and Dihydrorhodamine 123, respectively, in sensory and supporting cells. A 1-h GM exposure significantly increased O 2 ·-formation in IHCs and increased H 2 O 2 formation in all cell types. At the same time point, GM significantly increased manganese superoxide dismutase (MnSOD) levels while significantly decreasing copper/zinc superoxide dismutase (CuZnSOD) in cochlear sensory cells. This suggests (1) a rapid conversion of highly reactive O 2 ·-to H 2 O 2 during the acute stage of ototoxic antibiotic exposure and (2) that the endogenous antioxidant system is significantly altered by AGs. Fluorescence intensity-based measurements of reduced nicotinamide adenine dinucleotide (phosphate) [NAD(P)H] and mitochondrial membrane potential were measured to determine if increases in GM-induced ROS production were correlated with changes in mitochondrial metabolism. This project provides a basis for understanding the mechanisms of mitochondrial ROS production in cochlear cells exposed to ototoxic antibiotics. Understanding the nature of ototoxic antibiotic-induced changes in mitochondrial metabolism is critical for developing hearing loss treatment and prevention strategies.
UR - http://www.scopus.com/inward/record.url?scp=85056420773&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85056420773&partnerID=8YFLogxK
U2 - 10.1117/1.JBO.24.5.051403
DO - 10.1117/1.JBO.24.5.051403
M3 - Article
C2 - 30411553
AN - SCOPUS:85056420773
VL - 24
JO - Journal of Biomedical Optics
JF - Journal of Biomedical Optics
SN - 1083-3668
IS - 5
M1 - 051403
ER -