Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Mechanosensory hair cells express two molecularly distinct mechanotransduction channels

Abstract

Auditory hair cells contain mechanotransduction channels that rapidly open in response to sound-induced vibrations. We report here that auditory hair cells contain two molecularly distinct mechanotransduction channels. One ion channel is activated by sound and is responsible for sensory transduction. This sensory transduction channel is expressed in hair cell stereocilia, and previous studies show that its activity is affected by mutations in the genes encoding the transmembrane proteins TMHS, TMIE, TMC1 and TMC2. We show here that the second ion channel is expressed at the apical surface of hair cells and that it contains the Piezo2 protein. The activity of the Piezo2-dependent channel is controlled by the intracellular Ca2+ concentration and can be recorded following disruption of the sensory transduction machinery or more generally by disruption of the sensory epithelium. We thus conclude that hair cells express two molecularly and functionally distinct mechanotransduction channels with different subcellular distributions.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Expression of Piezo1 and Piezo2 in the inner ear.
Figure 2: Analysis of hearing function.
Figure 3: Piezo2 localization in hair cells.
Figure 4: Hair bundle morphology in Piezo2-cko mice.
Figure 5: Analysis of normal-polarity and reverse-polarity currents.
Figure 6: Effect of the intracellular Ca2+ concentration on reverse-polarity currents.
Figure 7: Maturation of mechanotransduction in OHCs from Piezo2-null mice and effects of mechanical disruption of the sensory epithelium on channel activity.

References

  1. Gillespie, P.G. & Müller, U. Mechanotransduction by hair cells: models, molecules, and mechanisms. Cell 139, 33–44 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Beurg, M., Fettiplace, R., Nam, J.H. & Ricci, A.J. Localization of inner hair cell mechanotransducer channels using high-speed calcium imaging. Nat. Neurosci. 12, 553–558 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Kurima, K. et al. TMC1 and TMC2 localize at the site of mechanotransduction in mammalian inner ear hair cell stereocilia. Cell Rep. 12, 1606–1617 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Xiong, W. et al. TMHS is an integral component of the mechanotransduction machinery of cochlear hair cells. Cell 151, 1283–1295 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Zhao, B. et al. TMIE is an essential component of the mechanotransduction machinery of cochlear hair cells. Neuron 84, 954–967 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Labay, V., Weichert, R.M., Makishima, T. & Griffith, A.J. Topology of transmembrane channel-like gene 1 protein. Biochemistry 49, 8592–8598 (2010).

    Article  CAS  PubMed  Google Scholar 

  7. Kawashima, Y. et al. Mechanotransduction in mouse inner ear hair cells requires transmembrane channel-like genes. J. Clin. Invest. 121, 4796–4809 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Kim, K.X. & Fettiplace, R. Developmental changes in the cochlear hair cell mechanotransducer channel and their regulation by transmembrane channel-like proteins. J. Gen. Physiol. 141, 141–148 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Pan, B. et al. TMC1 and TMC2 are components of the mechanotransduction channel in hair cells of the mammalian inner ear. Neuron 79, 504–515 (2013).

    Article  CAS  PubMed  Google Scholar 

  10. Kim, K.X. et al. The role of transmembrane channel-like proteins in the operation of hair cell mechanotransducer channels. J. Gen. Physiol. 142, 493–505 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Kindt, K.S., Finch, G. & Nicolson, T. Kinocilia mediate mechanosensitivity in developing zebrafish hair cells. Dev. Cell 23, 329–341 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Marcotti, W. et al. Transduction without tip links in cochlear hair cells is mediated by ion channels with permeation properties distinct from those of the mechano-electrical transducer channel. J. Neurosci. 34, 5505–5514 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  13. Waguespack, J., Salles, F.T., Kachar, B. & Ricci, A.J. Stepwise morphological and functional maturation of mechanotransduction in rat outer hair cells. J. Neurosci. 27, 13890–13902 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Alagramam, K.N. et al. Mutations in protocadherin 15 and cadherin 23 affect tip links and mechanotransduction in mammalian sensory hair cells. PLoS One 6, e19183 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Beurg, M., Xiong, W., Zhao, B., Müller, U. & Fettiplace, R. Subunit determination of the conductance of hair-cell mechanotransducer channels. Proc. Natl. Acad. Sci. USA 112, 1589–1594 (2015).

    Article  CAS  PubMed  Google Scholar 

  16. Beurg, M., Kim, K.X. & Fettiplace, R. Conductance and block of hair-cell mechanotransducer channels in transmembrane channel-like protein mutants. J. Gen. Physiol. 144, 55–69 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Beurg, M., Goldring, A.C. & Fettiplace, R. The effects of Tmc1 Beethoven mutation on mechanotransducer channel function in cochlear hair cells. J. Gen. Physiol. 146, 233–243 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Coste, B. et al. Piezo1 and Piezo2 are essential components of distinct mechanically activated cation channels. Science 330, 55–60 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Coste, B. et al. Piezo proteins are pore-forming subunits of mechanically activated channels. Nature 483, 176–181 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Honoré, E., Martins, J.R., Penton, D., Patel, A. & Demolombe, S. The piezo mechanosensitive ion channels: may the force be with you! Rev. Physiol. Biochem. Pharmacol. 169, 25–41 (2015).

    Article  PubMed  CAS  Google Scholar 

  21. Schug, N. et al. Differential expression of otoferlin in brain, vestibular system, immature and mature cochlea of the rat. Eur. J. Neurosci. 24, 3372–3380 (2006).

    Article  PubMed  Google Scholar 

  22. Yasunaga, S. et al. A mutation in OTOF, encoding otoferlin, a FER-1-like protein, causes DFNB9, a nonsyndromic form of deafness. Nat. Genet. 21, 363–369 (1999).

    Article  CAS  PubMed  Google Scholar 

  23. Woo, S.H. et al. Piezo2 is required for Merkel-cell mechanotransduction. Nature 509, 622–626 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Madisen, L. et al. A robust and high-throughput Cre reporting and characterization system for the whole mouse brain. Nat. Neurosci. 13, 133–140 (2010).

    Article  CAS  PubMed  Google Scholar 

  25. Nornes, H.O., Dressler, G.R., Knapik, E.W., Deutsch, U. & Gruss, P. Spatially and temporally restricted expression of Pax2 during murine neurogenesis. Development 109, 797–809 (1990).

    Article  CAS  PubMed  Google Scholar 

  26. Groves, A.K. & Bronner-Fraser, M. Competence, specification and commitment in otic placode induction. Development 127, 3489–3499 (2000).

    Article  CAS  PubMed  Google Scholar 

  27. Hutson, M.R., Lewis, J.E., Nguyen-Luu, D., Lindberg, K.H. & Barald, K.F. Expression of Pax2 and patterning of the chick inner ear. J. Neurocytol. 28, 795–807 (1999).

    Article  CAS  PubMed  Google Scholar 

  28. Ohyama, T. & Groves, A.K. Generation of Pax2-Cre mice by modification of a Pax2 bacterial artificial chromosome. Genesis 38, 195–199 (2004).

    Article  CAS  PubMed  Google Scholar 

  29. Rowitch, D.H. & McMahon, A.P. Pax-2 expression in the murine neural plate precedes and encompasses the expression domains of Wnt-1 and En-1. Mech. Dev. 52, 3–8 (1995).

    Article  CAS  PubMed  Google Scholar 

  30. Ranade, S.S. et al. Piezo1, a mechanically activated ion channel, is required for vascular development in mice. Proc. Natl. Acad. Sci. USA 111, 10347–10352 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Hardisty-Hughes, R.E., Parker, A. & Brown, S.D. A hearing and vestibular phenotyping pipeline to identify mouse mutants with hearing impairment. Nat. Protoc. 5, 177–190 (2010).

    Article  CAS  PubMed  Google Scholar 

  32. Ashmore, J. Cochlear outer hair cell motility. Physiol. Rev. 88, 173–210 (2008).

    Article  CAS  PubMed  Google Scholar 

  33. Fettiplace, R. Active hair bundle movements in auditory hair cells. J. Physiol. (Lond.) 576, 29–36 (2006).

    Article  CAS  Google Scholar 

  34. Ashmore, J.F. Forward and reverse transduction in the mammalian cochlea. Neurosci. Res. 12 (Suppl.), S39–S50 (1990).

    CAS  Google Scholar 

  35. Santos-Sacchi, J. Reversible inhibition of voltage-dependent outer hair cell motility and capacitance. J. Neurosci. 11, 3096–3110 (1991).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Grillet, N. et al. Harmonin mutations cause mechanotransduction defects in cochlear hair cells. Neuron 62, 375–387 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Beurg, M., Goldring, A.C., Ricci, A.J. & Fettiplace, R. Development and localization of reverse-polarity mechanotransducer channels in cochlear hair cells. Proc. Natl. Acad. Sci. USA 113, 6767–6772 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Beurg, M., Nam, J.H., Chen, Q. & Fettiplace, R. Calcium balance and mechanotransduction in rat cochlear hair cells. J. Neurophysiol. 104, 18–34 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Corey, D.P. & Hudspeth, A.J. Kinetics of the receptor current in bullfrog saccular hair cells. J. Neurosci. 3, 962–976 (1983).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. Lumpkin, E.A. & Hudspeth, A.J. Detection of Ca2+ entry through mechanosensitive channels localizes the site of mechanoelectrical transduction in hair cells. Proc. Natl. Acad. Sci. USA 92, 10297–10301 (1995).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  41. Assad, J.A., Shepherd, G.M. & Corey, D.P. Tip-link integrity and mechanical transduction in vertebrate hair cells. Neuron 7, 985–994 (1991).

    Article  CAS  PubMed  Google Scholar 

  42. Hackney, C.M., Mahendrasingam, S., Penn, A. & Fettiplace, R. The concentrations of calcium buffering proteins in mammalian cochlear hair cells. J. Neurosci. 25, 7867–7875 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Dubin, A.E. et al. Inflammatory signals enhance piezo2-mediated mechanosensitive currents. Cell Rep. 2, 511–517 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Lelli, A., Asai, Y., Forge, A., Holt, J.R. & Géléoc, G.S. Tonotopic gradient in the developmental acquisition of sensory transduction in outer hair cells of the mouse cochlea. J. Neurophysiol. 101, 2961–2973 (2009).

    Article  PubMed  PubMed Central  Google Scholar 

  45. Eijkelkamp, N. et al. A role for Piezo2 in EPAC1-dependent mechanical allodynia. Nat. Commun. 4, 1682 (2013).

    Article  CAS  PubMed  Google Scholar 

  46. Ding, J.P., Salvi, R.J. & Sachs, F. Stretch-activated ion channels in guinea pig outer hair cells. Hear. Res. 56, 19–28 (1991).

    Article  CAS  PubMed  Google Scholar 

  47. Iwasa, K.H., Li, M.X., Jia, M. & Kachar, B. Stretch sensitivity of the lateral wall of the auditory outer hair cell from the guinea pig. Neurosci. Lett. 133, 171–174 (1991).

    Article  CAS  PubMed  Google Scholar 

  48. Rybalchenko, V. & Santos-Sacchi, J. Cl- flux through a non-selective, stretch-sensitive conductance influences the outer hair cell motor of the guinea-pig. J. Physiol. (Lond.) 547, 873–891 (2003).

    Article  CAS  Google Scholar 

  49. Lee, W. et al. Synergy between Piezo1 and Piezo2 channels confers high-strain mechanosensitivity to articular cartilage. Proc. Natl. Acad. Sci. USA 111, E5114–E5122 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  50. Cahalan, S.M. et al. Piezo1 links mechanical forces to red blood cell volume. eLife 4, 2 (2015).

    Article  Google Scholar 

  51. Woo, S.H. et al. Piezo2 is the principal mechanotransduction channel for proprioception. Nat. Neurosci. 18, 1756–1762 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  52. Schwander, M. et al. A forward genetics screen in mice identifies recessive deafness traits and reveals that pejvakin is essential for outer hair cell function. J. Neurosci. 27, 2163–2175 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  53. Grillet, N. et al. Mutations in LOXHD1, an evolutionarily conserved stereociliary protein, disrupt hair cell function in mice and cause progressive hearing loss in humans. Am. J. Hum. Genet. 85, 328–337 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Beurg, M., Tan, X. & Fettiplace, R. A prestin motor in chicken auditory hair cells: active force generation in a nonmammalian species. Neuron 79, 69–81 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  55. Zhu, Y. et al. Active cochlear amplification is dependent on supporting cell gap junctions. Nat. Commun. 4, 1786 (2013).

    Article  PubMed  CAS  Google Scholar 

Download references

Acknowledgements

We thank S.-H. Woo and K. Nonomura (The Scripps Research Institute, La Jolla, California, USA) for providing genetically modified mice for Piezo2 and for comments on the manuscript. A. Patapoutian is an investigator of the Howard Hughes Medical Institute. U. Müller is a Bloomberg Distinguished Professor. This research was funded by NIDCD grants DC005965, DC007704, DC014713 (U. Müller); DC01362 (R. Fettiplace); NIDCR DEo22358 (A. Patapoutian); the Dorris Neuroscience Center; the Skaggs Institute for Chemical Biology (U. Müller).

Author information

Authors and Affiliations

Authors

Contributions

All authors contributed to experimental design. Z.W. and N.G. designed and performed most of the experiments. S.R. generated some of the genetically modified mice; C.C. and N.Z. participated in gene expression studies; B.Z. carried out electron microscopic studies; B.C. analyzed effects of pharmacological inhibitors on Piezo2 expressed in heterologous cells; S.H.-P. carried out auditory brain stem response and distortion product otoacoustic emissions recordings and participated in the generation of genetically modified mice; and M.B. analyzed effects of calcium on mechanotransduction. U.M., A.P. and R.F. supervised the experiments and participated in data analysis and interpretation. U.M. and Z.W. wrote the manuscript with substantial input from the other authors.

Corresponding author

Correspondence to Ulrich Müller.

Ethics declarations

Competing interests

Ulrich Müller is a cofounder of Decibel Therapeutics.

Integrated supplementary information

Supplementary Figure 1 Piezo2-Cre;Ai9 expression in P2 mouse brain

Piezo2 is not expressed in neurons of the auditory hindbrain and is restricted to endothelial cells, trigeminal nerve fibers, neuropil of trigeminal nuclei and the dorsal horn of the rostral spinal cord. All images are from flattened projections of confocal images taken from sagittal sections at various mediolateral locations of P2 Piezo2-Cre; Ai9 (red) counterstained for DAPI, a nuclear marker (blue). (A) Piezo2 is expressed only by endothelial cells in P2 cerebral cortex and hippocampus. (B) Piezo2 is expressed by endothelial cells in the P2 cerebellum and the choroid plexus of the fourth ventricle but not by any other cell types. (C) Piezo2 is expressed by endothelial cells but no other cell types in the cochlear nucleus nor fibers contacting the cochlear nucleus. Note the labeled trigeminal nerve fibers. (D) The superior olivary nucleus, the major source of olivocochlear efferent neurons, does not express Piezo2, except for endothelial cells. No fibers contacting the superior olivary nucleus express Piezo2. (E) The inferior colliculus, cerebellum and cochlear nuclei do not express Piezo2, except for endothelial cells. Piezo2 is expressed in the trigeminal nerve, trigeminal nuclei, and dorsal horn of the rostral spinal cord. Scale bar in (E) = 500 μm and applies to all images.

Supplementary Figure 2 Analysis of vestibular function

A forced swim test was used to analyze vestibular function. Tail activity, hind leg activity, head position, swimming direction, and body posture in water were recorded. Results are represented as mean ± standard error of the mean (SE). P = 1, U = 21 by Mann-Whitney test. The number of tested mice is indicated.

Supplementary Figure 3 Analysis of nonlinear capacitance (NLC) of apical OHCs from P15 mice.

(A) Summary data showing the capacitance change when cells were depolarized from -150 to 100 mV. (B,C) Statistical analyses showing that there was no obvious difference both in membrane potential with peak capacitance (B, unpaired t-test, p=0.314, t(10) = 1.067) and in peak capacitance (C, unpaired t-test, p=0.637, t(10) = 0.489) between controls and Piezo2cko (PZ2cko) mice. Values are mean ± SEM.

Supplementary Figure 4 Analysis of force–current relationship of OHCs with fluid jet

Normalized current fluidjet voltage plots of OHCs obtained from P7 pups. The voltage is the driving voltage applied to the fluid jet piezo disc. Values are mean ± SEM. Mann-Whitney test between control and PZ2cko groups: -10 V, P = 0.488, U = 36; -8 V, P = 0.307, U = 32; -6 V, P = 0.967, U = 44; -4 V, P = 0.178, U = 28; -2 V, P = 0.348, U = 33; 0 V, P = 0.236, U = 30; 2 V, P = 0.438, U = 35; 4 V, P = 0.596, U = 38; 6 V, P = 0.391, 34; 8 V, P = 0.838, U = 42; 10 V, P = 0.391, U = 34; 12 V, P = 0.348, U = 33; 14 V, P = 0.27, U = 31; 16 V, P = 0.54, U = 37; 18 V, P = 0.567, U = 37.5; 20 V, P = 0.307, U = 32; 22 V, P = 0.595, U = 38; 24 V, P = 0.111, U = 25; 26 V, P = 0.595, U = 38; 28 V, P = 0.624, U = 28.5; 30 V, P = 0.653, U = 39.

Supplementary Figure 5 Analysis of sensitivity of Piezo2 currents to dihydrostreptomycin (DHS)

Representative mechanotransduction currents in HEK293 cells overexpressing Piezo2 and summary data showing the effect of 100 μM DHS on mechanotransduction currents in the presents of different extracellular Ca2+ concentrations (100 μM and 2.5 mM). Current traces were recorded with 2.5 mM Ca2+ in bath solution. Values are mean ± SEM.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wu, Z., Grillet, N., Zhao, B. et al. Mechanosensory hair cells express two molecularly distinct mechanotransduction channels. Nat Neurosci 20, 24–33 (2017). https://doi.org/10.1038/nn.4449

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nn.4449

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing