Defective Tmprss3-Associated Hair Cell Degeneration in Inner Ear Organoids

Stem Cell Reports. 2019 Jul 9;13(1):147-162. doi: 10.1016/j.stemcr.2019.05.014. Epub 2019 Jun 13.

Abstract

Mutations in the gene encoding the type II transmembrane protease 3 (TMPRSS3) cause human hearing loss, although the underlying mechanisms that result in TMPRSS3-related hearing loss are still unclear. We combined the use of stem cell-derived inner ear organoids with single-cell RNA sequencing to investigate the role of TMPRSS3. Defective Tmprss3 leads to hair cell apoptosis without altering the development of hair cells and the formation of the mechanotransduction apparatus. Prior to degeneration, Tmprss3-KO hair cells demonstrate reduced numbers of BK channels and lower expressions of genes encoding calcium ion-binding proteins, suggesting a disruption in intracellular homeostasis. A proteolytically active TMPRSS3 was detected on cell membranes in addition to ER of cells in inner ear organoids. Our in vitro model recapitulated salient features of genetically associated inner ear abnormalities and will serve as a powerful tool for studying inner ear disorders.

Keywords: TMPRSS3; deafness; degeneration; disease modeling; embryonic stem cell; hair cell; inner ear; organoid; vestibular system.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis / genetics
  • Cell Membrane / metabolism
  • Codon, Nonsense
  • Ear, Inner / pathology*
  • Gene Knockout Techniques
  • Hair Cells, Auditory, Inner / pathology*
  • Homeostasis / genetics
  • Humans
  • Large-Conductance Calcium-Activated Potassium Channels / metabolism
  • Mechanotransduction, Cellular
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Mice
  • Organoids / cytology*
  • Sequence Analysis, RNA
  • Serine Proteases / genetics*
  • Serine Proteases / metabolism
  • Single-Cell Analysis

Substances

  • Codon, Nonsense
  • Large-Conductance Calcium-Activated Potassium Channels
  • Membrane Proteins
  • Serine Proteases
  • Tmprss3 protein, mouse