Inflammation up-regulates cochlear expression of TRPV1 to potentiate drug-induced hearing loss

Sci Adv. 2019 Jul 17;5(7):eaaw1836. doi: 10.1126/sciadv.aaw1836. eCollection 2019 Jul.

Abstract

Aminoglycoside antibiotics are essential for treating life-threatening bacterial infections, despite the risk of lifelong hearing loss. Infections induce inflammation and up-regulate expression of candidate aminoglycoside-permeant cation channels, including transient receptor potential vanilloid-1 (TRPV1). Heterologous expression of TRPV1 facilitated cellular uptake of (fluorescently tagged) gentamicin that was enhanced by agonists, and diminished by antagonists, of TRPV1. Cochlear TRPV1 was immunolocalized near the apical membranes of sensory hair cells, adjacent supporting cells, and marginal cells in the stria vascularis. Exposure to immunostimulatory lipopolysaccharides, to simulate of bacterial infections, increased cochlear expression of TRPV1 and hair cell uptake of gentamicin. Lipopolysaccharide exposure exacerbated aminoglycoside-induced auditory threshold shifts and loss of cochlear hair cells in wild-type, but not in heterozygous Trpv1+/- or Trpv1 knockout, mice. Thus, TRPV1 facilitates cochlear uptake of aminoglycosides, and bacteriogenic stimulation upregulates TRPV1 expression to exacerbate cochleotoxicity. Furthermore, loss-of-function polymorphisms in Trpv1 can protect against immunogenic exacerbation of aminoglycoside-induced cochleotoxicity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminoglycosides / adverse effects*
  • Animals
  • Calcium / metabolism
  • Cell Survival / drug effects
  • Cells, Cultured
  • Disease Models, Animal
  • Gene Expression Regulation
  • Gene Knockdown Techniques
  • Gentamicins / adverse effects
  • Hair Cells, Auditory / drug effects*
  • Hair Cells, Auditory / metabolism*
  • Hair Cells, Auditory / ultrastructure
  • Hearing Loss / etiology*
  • Hearing Loss / metabolism
  • Hearing Loss / physiopathology
  • Inflammation / complications*
  • Inflammation / genetics*
  • Ion Channel Gating
  • Mice
  • Mice, Knockout
  • TRPV Cation Channels / genetics*
  • Toll-Like Receptor 4 / metabolism

Substances

  • Aminoglycosides
  • Gentamicins
  • TRPV Cation Channels
  • TRPV1 protein, mouse
  • Toll-Like Receptor 4
  • Calcium