Promising research continues for cure on hearing loss

For 2010, the American Hearing Research Foundation will be funding six grants. This year, we received the highest number of grant proposals in our history—41 proposals in all. The following grants will begin on January 1, 2010, and will be funded for $20,000 for one year.

Douglas Cotanche, Ph.D.
Boston University School of Medicine, Massachusetts
“Cell fate regulation in cochlear development and regeneration”

Birds can regenerate hair cells in the cochlea once they are lost – an ability that mammals do not possess. When hair cells are lost in birds, following loud noise exposure or administration of ototoxic drugs in the lab, the supporting cells around the hair cells turn into new hair cells. Cotanche and colleagues hope that by studying this process in birds, they will be able to induce the mammalian cochlear cells to undergo a similar regeneration. Specifically, the researchers will study the genetics involved in supporting cell transduction into hair cells in chicks and mice. They hope to gain understanding of the molecular processes involved in hair cell regeneration in order to cause the same regeneration in mammalian cells.

Saima Riazuddin, Ph.D.
Cincinnati Children’s Hospital Medical Center, Ohio
“Generation and characterization of a mouse model of DFNB26”

More than 100 gene locations have been indentified as contributing to hearing loss in its various forms. However, knowledge on how genes affect hearing remain inadequate. Researchers need to be able to study and develop animal models to study disease causing mutations, and to define the molecular pathways leading to hearing loss to ultimately develop therapeutic approaches to treating deafness. Riazuddin and colleagues have recently mapped a deafness causing gene called DFNB26 in an extended family. They also discovered another gene that that suppresses the deafness-causing gene. The researchers hope to study how these two genes work to cause and prevent deafness among the members of this family by developing mice with these genes. The study will provide valuable models for defining the role of DFNB26 in the inner ear and to develop treatment strategies for this disease.

Angelika Doetzlhofer, Ph.D.
Johns Hopkins University School of Medicine, Baltimore, Maryland
“Response of supporting cell to hair loss in the mammalian cochlea”

Doetzelhofer and colleagues hope to uncover the molecular signals activated in supporting cells after hair cell loss, and what pathways may inhibit hair cell regeneration. In mammals, hair cells only develop during embryonic development, and when hair cells are lost, they are not replaced. However, in birds, when hair cells are lost, supporting cells can transform into new hair cells. Researchers believe that supporting hair cells, even in mammals, have the ability to transform into hair cells, but that signals from adjacent cells and/or dying hair cells block supporting cells from becoming new hair cells. Doetzlhofer and colleagues will investigate these inhibitory pathways and will look at changes in gene expression in supporting cells as hair cells are lost. Understanding the molecular mechanisms that prevent hair cell regeneration in mammals is a crucial first stem in developing successful hair cell replacement therapies.