The Path to a Cure for Hearing Loss and Tinnitus

By Laura Friedman

On May 21, 2015, Hearing Health Foundation hosted its first live-video research briefing as part of our effort to provide regular updates on our research programs and progress. Through these briefings, our goal is for our attendees to obtain new information and understanding about hearing loss, prevention and research toward a cure.

During this inaugural research briefing, Dr. Peter Barr-Gillespie, Scientific Director, Hearing Restoration Project presented the Hearing Restoration Project (HRP). The HRP was founded in 2011 and is the first and only international research consortium focused on investigating hair cell regeneration as a cure for hearing loss and tinnitus. The overarching principle of the consortium is collaboration: open sharing of data and ideas. The HRP consortium consists of 14 of the top investigators in the audiological space, as well as a scientific director, Dr. Barr-Gillespie.

We wanted to share with you highlights from the presentation, which is available to watch with live captioning or to read with notes summarizing each slide

  1. History of Hearing Health Foundation

    • Founded in 1958, established reputation for pioneering breakthroughs in hearing and balance research.

      • Early supporters of the revolutionary cochlear implant. Today, over 220,000 children and adults benefit.

      • Advocated for the passage of Universal Newborn Hearing Screening legislation in the 1990s. Today, 97% of newborns are tested for hearing loss at birth.

      • The Emerging Research Grants Program provides seed funding for researchers in hearing and balance science such as discoveries in hair cell regeneration, tinnitus, hyperacusis, and Ménière’s research. 

  2. The Challenge

    • In the past century, the primary treatment for hearing loss has been hearing aids and cochlear implants. While these have been very successful treatments, they have limitations.

    • For this century, we have a number of different avenues for more effective therapy. 

      • Preventing the damage to the hair cells to preserve hearing. By generating greater awareness of the effects of hearing loss, we aim encourage people of all ages to protect their ears.

      • Gene therapy, targeting those who have lost hearing due to genetic disorders.

      • The majority of people who have lost hearing have done so through noise damage or aging, and may be candidates for hair cell regeneration/restoration.

  3. HRP Consortium History & Model

    • One of the key facets of the HRP’s approach is that we use three different animal models for studying hair cell regeneration
      • Two of those models, the chick and the zebrafish, show robust hair cell regeneration.
        • f you damage the hair cells of a chick or a fish, within a short time—only a day or two for the fish, a few weeks for the chick—the hair cells come back; new hair cells are formed.
          • So, that's spectacular, because it tells us that animals are capable of regenerating hair cells. 
      • y contrast, the mouse is our other experimental model. Like in the human, the mouse shows no hair cell regeneration after a few days following birth.
        • You can damage the hair cells in the mouse and as far as we can tell, nothing much happens in terms of restoring hair cells. So, if we can figure out how to regenerate hair cells in the mouse, then we will be able to regenerate hair cells in people.
  4. HRP Strategic Research Plan

    • Our strategic plan consists of three separate phases. We have already made a lot of progress on Phase 1 and we have initiated Phase 2:

      • Phase 1 – Discovery research:  Compare the fish, chick, and mouse to discover pro- or anti-regeneration pathways and determine supporting cell fates.

      • Phase 2 – Pathway validation: Verify pathways using fish, chick, and mouse models and describe regeneration strategies.

      • Phase 3 – Develop therapies and treatment options: Identify drugs that trigger hair cell regeneration in the mouse model.

  5. Progress To-Date

    • Progress on Phase 1: We've identified a variety of candidates for hair cell regeneration and the pathways that are necessary. 

      • We have too many, so we really are continuing to use bioinformatics methods to winnow down and determine which are most important.

      • We have definitively shown, at least in the mouse, the specialized supporting cells remain.

      • We know now what our target cells are for triggering hair cell regeneration. 

    • Phase 2 has begun, but we haven’t stopped Phase 1: 

      • We've got multiple approaches to try and see whether or not we can block regeneration in the fish and chick or stimulate regeneration in the mouse.

    • Phase 3 is in sight:

      • Experimental models from Phase 2 will be used to screen for drugs—using the mouse first

  6. The Next Five Years

    • With your help, we can continue to quicken the pace towards a cure. Here’s our plan for the next five years: 

      • Phase 1 will continue: more candidate generation for Phase 2

      • Phase 2 (pathway verification) already initiated in zebrafish, mouse, chick (low throughput)

      • Phase 2 must be scaled up: many more genes, combinatorial approaches; cell lines for screening

      • Phase 3 (drug screening) requires the right screening model, which will come out of Phase 2.

The Future is Very Bright – But we need your support!

Hair cell regeneration is a plausible goal for eventual treatment of hearing and balance disorders. The question is not if we will regenerate hair cells in humans, but when.  However, we need your support to continue this vital research and find a cure! Please make your gift today.  

 

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