Role of protein in development of new hearing hair cells
Finding could lead to future treatments for hearing loss

Date:
September 11, 2020
Source:
University of Maryland School of Medicine
Summary:
Researchers have conducted a study that has determined the role that
a critical protein plays in the development of hair cells. These
hair cells are vital for hearing. Some of these cells amplify
sounds that come into the ear, and others transform sound waves
into electrical signals that travel to the brain.



FULL STORY ========================================================================== Researchers at the University of Maryland School of Medicine (UMSOM) have conducted a study that has determined the role that a critical protein
plays in the development of hair cells. These hair cells are vital for
hearing. Some of these cells amplify sounds that come into the ear, and
others transform sound waves into electrical signals that travel to the
brain. Ronna Hertzano, MD, PhD, Associate Professor in the Department of Otorhinolaryngology Head and Neck Surgery at UMSOM and Maggie Matern,
PhD, a postdoctoral fellow at Stanford University, demonstrated that
the protein, called GFI1, may be critical for determining whether an
embryonic hair cell matures into a functional adult hair cell or becomes
a different cell that functions more like a nerve cell or neuron.


==========================================================================
The study was published in the journal Development, and was conducted
by physician-scientists and researchers at the UMSOM Department of Otorhinolaryngology Head and Neck Surgery and the UMSOM Institute for
Genome Sciences (IGS), in collaboration with researchers at the Sackler
School of Medicine at Tel Aviv University in Israel.

Hearing relies on the proper functioning of specialized cells within the
inner ear called hair cells. When the hair cells do not develop properly
or are damaged by environmental stresses like loud noise, it results in
a loss of hearing function.

In the United States, the prevalence of hearing loss doubles with every
10-year increase in age, affecting about half of all adults in their 70s
and about 80 percent of those who are over age 85. Researchers have been focusing on describing the developmental steps that lead to a functional
hair cell, in order to potentially generate new hair cells when old ones
are damaged.

Hair cells in the inner ear To conduct her latest study, Dr. Hertzano
and her team utilized cutting-edge methods to study gene expression in
the hair cells of genetically modified newborn mice that did not produce
GFI1. They demonstrated that, in the absence of this vital protein,
embryonic hair cells failed to progress in their development to become
fully functional adult cells. In fact, the genes expressed by these
cells indicated that they were likely to develop into neuron-like cells.

"Our findings explain why GFI1 is critical to enable embryonic cells to progress into functioning adult hair cells," said Dr. Hertzano. "These
data also explain the importance of GFI1 in experimental protocols to regenerate hair cells from stem cells. These regenerative methods have
the potential of being used for patients who have experienced hearing
loss due to age or environmental factors like exposure to loud noise."
Dr. Hertzano first became interested in GFI1 while completing her M.D.,
Ph.D.

at Tel Aviv University. As part of her dissertation, she discovered that
the hearing loss resulting from mutations in another protein called POU4F3 appeared to largely result from a loss of GFI1 in the hair cells. Since
then, she has been conducting studies to discover the role of GFI1
and other proteins in hearing. Other research groups in the field are
now testing these proteins to determine whether they can be used as a "cocktail" to regenerate lost hair cells and restore hearing.

"Hearing research has been going through a Renaissance period, not only
from advances in genomics and methodology, but also thanks to its uniquely collaborative nature among researchers," said Dr. Herzano.

The new study was funded by the National Institute on Deafness and
Other Communication Disorders (NIDCD) which is part of the National
Institutes of Health (NIH). It was also funded by the Binational
Scientific Foundation (BSF).

"This is an exciting new finding that underscores the importance of
basic research to lay the foundation for future clinical innovations,"
said E. Albert Reece, MD, PhD, MBA, Executive Vice President for
Medical Affairs, UM Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean, University of Maryland School of
Medicine. "Identifying the complex pathways that lead to normal hearing
could prove to be the key for reversing hearing loss in millions of
Americans."

========================================================================== Story Source: Materials provided by
University_of_Maryland_School_of_Medicine. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Maggie S. Matern, Beatrice Milon, Erika L. Lipford, Mark McMurray,
Yoko
Ogawa, Andrew Tkaczuk, Yang Song, Ran Elkon, Ronna Hertzano. GFI1
functions to repress neuronal gene expression in the developing
inner ear hair cells. Development, 2020; 147 (17): dev186015 DOI:
10.1242/ dev.186015 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/09/200911200012.htm

--- up 2 weeks, 4 days, 6 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)