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The Latest Research on Hair Cell Regeneration to Restore Hearing Hearing Health Foundation’s collaborative Hearing Restoration Project consortium headlined a scientific conference in New York City to advance cures for hearing loss. By Lauren McGrath
The New York Academy of Sciences (NYAS) hosted “Hearing Restoration and Hair Cell Regeneration,” a symposium in early October 2019 to connect internationally recognized hearing loss experts from academia, industry, government, and nonprofit organizations. Hearing Health Foundation (HHF) scientists spoke and presented, and HHF also served as a promotional partner for the conference. Armed with the knowledge that non-mammalian species have the ability to regenerate their inner ear sensory hair cells and restore their hearing, 11 speakers delved into the science during the full-day symposium in New York City. This included two researchers who are funded by HHF through the Hearing Restoration Project (HRP): HRP scientific director Peter Barr-Gillespie, Ph.D., of Oregon Health & Science University, and HRP consortium member Tatjana Piotrowski, Ph.D., of the Stowers Institute for Medical Research in Missouri. NYAS program manager Kari Fischer, Ph.D., and NYAS Scientific Organizing Committee member Michael Franti, Ph.D., introduced the conference, which began with keynote speaker Barr-Gillespie and his presentation, “A Cross-Species Approach to Hair Cell Regeneration.” This presentation was an overview of the HRP’s work investigating the restoration of hearing in humans by converting remaining cells in the inner ear into functional hair cells. Barr-Gillespie noted that two pivotal papers from the late 1980s, “Regeneration of Sensory Cells After Acoustic Trauma” and “Hair Cell Regeneration After Acoustic Trauma in Coturnix Quail,” which were coauthored by HHF Emerging Research Grants (ERG) scientists Douglas Cotanche, Ph.D., and Edwin Rubel, Ph.D., respectively, added greatly to the knowledge of how hearing works. These HHF-funded discoveries that birds can spontaneously regenerate their hearing once it has been 26
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lost formed the basis of the HRP, established in 2011. The overarching principle of the HRP, Barr-Gillespie explained, is collaboration through the open sharing of data and ideas. Consortium members use a comparative approach, examining the hearing mechanisms of chickens and zebrafish, which both show robust hair cell regeneration, as well as mice, which do not show hair cell regeneration in the cochlea. Barr-Gillespie provided greater context on several active, species-specific projects led by consortium members. He noted that HRP members share their data through a portal, the gEAR (gene Expression Analysis Resource), developed by consortium member Ronna Hertzano, M.D., Ph.D., of the University of Maryland Medical Center, which enables analysis and visualization of complex data and resource-sharing among the greater scientific community. Barr-Gillespie posits that furthering our understanding of gene-regulatory networks used to build hair cells and maintain supporting cells will ultimately enable regeneration strategies. Piotrowski’s presentation, “Hair Cell Regeneration in the Zebrafish Lateral Line,” provided specifics that followed up on Barr-Gillespie’s overall summary of the consortium’s cross-species approach. Zebrafish lateral line cells are homologous to mammalian inner ear hair cells, but they detect water movement instead of sound in order to preserve their ability to orient themselves. Piotrowski’s lab investigates which genes, including transcription factors, guide the regeneration of hair cells and how these genes are regulated by enhancers. Enhancers are DNA sequences in the genome that increase the expression of nearby genes. Identifying the specific enhancers, for example, that are active in zebrafish regeneration provides a better set of candidate targets that could be useful in triggering regeneration in mice. The NYAS symposium also featured a poster session
