The role of PKCzeta in amikacin-induced apoptosis in the cochlea: prevention by aspirin

Apoptosis. 2007 Feb;12(2):333-42. doi: 10.1007/s10495-006-0580-0.

Abstract

Aminoglycoside antibiotics are ototoxic, inducing irreversible sensorineural hearing loss mediated by oxidative and excitotoxic stresses. The NF-kappaB pathway is involved in the response to aminoglycoside damage in the cochlea. However, the molecular mechanisms of this ototoxicity remain unclear. We investigated the expression of PKCzeta, a key regulator of NF-kappaB activation, in response to aminoglycoside treatment. Amikacin induced PKCzeta cleavage and nuclear translocation. These events were concomitant with chromatin condensation and paralleled the decrease in NF-kappaB (p65) levels in the nucleus. Amikacin also induced the nuclear translocation of apoptotic inducing factor (AIF). Prior treatment with aspirin prevented PKCzeta cleavage and nuclear translocation. Thus, aspirin counteracts the early effects of amikacin, thereby protecting hair cells and spiral ganglion neurons. These results demonstrate that PKCzeta acts as sentinel connecting specific survival pathways to mediate cellular responses to amikacin ototoxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amikacin / pharmacology*
  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology
  • Apoptosis / drug effects*
  • Apoptosis Inducing Factor / metabolism
  • Aspirin / pharmacology*
  • Audiometry, Evoked Response
  • Cell Nucleus / drug effects
  • Cell Nucleus / metabolism
  • Cochlea / cytology*
  • Cochlea / enzymology*
  • Male
  • Protein Kinase C / metabolism*
  • Protein Transport / drug effects
  • Rats
  • Rats, Inbred Lew
  • Spiral Ganglion / cytology
  • Spiral Ganglion / drug effects
  • Spiral Ganglion / metabolism
  • Subcellular Fractions / drug effects
  • Subcellular Fractions / enzymology
  • Transcription Factor RelA / metabolism

Substances

  • Anti-Bacterial Agents
  • Anti-Inflammatory Agents, Non-Steroidal
  • Apoptosis Inducing Factor
  • Transcription Factor RelA
  • Amikacin
  • protein kinase C zeta
  • Protein Kinase C
  • Aspirin