Researchers restore hearing in noise-deafened mouse: NIDCD-supported researchers use drug to grow new sensory hair cells in the inner ear

2013 ◽  
Development ◽  
2007 ◽  
Vol 134 (24) ◽  
pp. 4405-4415 ◽  
Author(s):  
S. Raft ◽  
E. J. Koundakjian ◽  
H. Quinones ◽  
C. S. Jayasena ◽  
L. V. Goodrich ◽  
...  

2005 ◽  
Vol 28 (1) ◽  
pp. 106-117 ◽  
Author(s):  
Ellen Reisinger ◽  
Ulrike Zimmermann ◽  
Marlies Knipper ◽  
Jost Ludwig ◽  
Nikolaj Klöcker ◽  
...  

PLoS ONE ◽  
2010 ◽  
Vol 5 (1) ◽  
pp. e8627 ◽  
Author(s):  
Geoffrey C. Horwitz ◽  
Andrea Lelli ◽  
Gwenaëlle S. G. Géléoc ◽  
Jeffrey R. Holt

2018 ◽  
Author(s):  
Itallia V. Pacentine ◽  
Teresa Nicolson

AbstractMutations in transmembrane inner ear (TMIE) cause deafness in humans; previous studies suggest involvement in the mechano-electrical transduction (MET) complex in sensory hair cells, but TMIE’s precise role is unclear. In tmie zebrafish mutants, we observed that GFP-tagged Tmc1 and Tmc2b, which are putative subunits of the MET channel, fail to target to the hair bundle. In contrast, overexpression of Tmie strongly enhances the targeting of Tmc2b-GFP to stereocilia. To identify the motifs of Tmie underlying the regulation of the Tmcs, we systematically deleted or replaced peptide segments. We then assessed localization and functional rescue of each mutated/chimeric form of Tmie in tmie mutants. We determined that the first putative helix was dispensable and identified a novel critical region of Tmie, the extracellular region and transmembrane domain, which mediates both mechanosensitivity and Tmc2b-GFP expression in bundles. Collectively, our results suggest that Tmie’s role in sensory hair cells is to target and stabilize Tmc subunits to the site of MET.Author summaryHair cells mediate hearing and balance through the activity of a pore-forming channel in the cell membrane. The transmembrane inner ear (TMIE) protein is an essential component of the protein complex that gates this so-called mechanotransduction channel. While it is known that loss of TMIE results in deafness, the function of TMIE within the complex is unclear. Using zebrafish as a deafness model, Pacentine and Nicolson demonstrate that Tmie is required for the localization of other essential complex members, the transmembrane channel-like (Tmc) proteins, Tmc1/2b. They then evaluate twelve unique versions of Tmie, each containing mutations to different domains of Tmie. This analysis reveals that some mutations in Tmie cause dysfunctional gating of the channel as demonstrated through reduced hair cell activity, and that these same dysfunctional versions also display reduced Tmc expression at the normal site of the channel. These findings link hair cell activity with the levels of Tmc in the bundle, reinforcing the currently-debated notion that the Tmcs are the pore-forming subunits of the mechanotransduction channel. The authors conclude that Tmie, through distinct regions, is involved in both trafficking and stabilizing the Tmcs at the site of mechanotransduction.


1990 ◽  
Vol 110 (4) ◽  
pp. 1055-1066 ◽  
Author(s):  
G P Richardson ◽  
S Bartolami ◽  
I J Russell

Immunological techniques have been used to generate both polyclonal and monoclonal antibodies specific for the apical ends of sensory hair cells in the avian inner ear. The hair cell antigen recognized by these antibodies is soluble in nonionic detergent, behaves on sucrose gradients primarily as a 16S particle, and, after immunoprecipitation, migrates as a polypeptide with a relative molecular mass of 275 kD on 5% SDS gels under reducing conditions. The antigen can be detected with scanning immunoelectron microscopy on the apical surface of the cell and on the stereocilia bundle but not on the kinocilium. Double label studies indicate that the entire stereocilia bundle is stained in the lagena macula (a vestibular organ), whereas in the basilar papilla (an auditory organ) only the proximal region of the stereocilia bundle nearest to the apical surface is stained. The monoclonal anti-hair cell antibodies do not stain brain, tongue, lung, liver, heart, crop, gizzard, small intestine, skeletal muscle, feather, skin, or eye tissues but do specifically stain renal corpuscles in the kidney. Experiments using organotypic cultures of the embryonic lagena macula indicate that the antibodies cause a significant increase in the steady-state stiffness of the stereocilia bundle but do not inhibit mechanotransduction. The antibodies should provide a suitable marker and/or tool for the purification of the apical sensory membrane of the hair cell.


Sign in / Sign up

Export Citation Format

Share Document