Nav: Home

Drug treatment could combat hearing loss

February 21, 2017

CAMBRIDGE, MA -- Within the inner ear, thousands of hair cells detect sound waves and translate them into nerve signals that allow us to hear speech, music, and other everyday sounds. Damage to these cells is one of the leading causes of hearing loss, which affects 48 million Americans.

Each of us is born with about 15,000 hair cells per ear, and once damaged, these cells cannot regrow. However, researchers at MIT, Brigham and Women's Hospital, and Massachusetts Eye and Ear have now discovered a combination of drugs that expands the population of progenitor cells (also called supporting cells) in the ear and induces them to become hair cells, offering a potential new way to treat hearing loss.

"Hearing loss is a real problem as people get older. It's very much of an unmet need, and this is an entirely new approach," says Robert Langer, the David H. Koch Institute Professor at MIT, a member of the Koch Institute for Integrative Cancer Research, and one of the senior authors of the study.

Jeffrey Karp, an associate professor of medicine at Brigham and Women's Hospital (BWH) and Harvard Medical School in Boston; and Albert Edge, a professor of otolaryngology at Harvard Medical School based at Massachusetts Eye and Ear, are also senior authors of the paper, which appears in the Feb. 21 issue of Cell Reports.

Lead authors are Will McLean, a recent PhD recipient at the Harvard-MIT Division of Health Sciences and Technology, and Xiaolei Yin, an instructor at Brigham and Women's and a research affiliate at the Koch Institute. Other authors are former MIT visiting student Lin Lu, Mass Eye and Ear postdoc Danielle Lenz, and Mass Eye and Ear research assistant Dalton McLean.

Cell regeneration

Noise exposure, aging, and some antibiotics and chemotherapy drugs can lead to hair cell death. In some animals, those cells naturally regenerate, but not in humans.

The research team began investigating the possibility of regenerating hair cells during an earlier study on cells of the intestinal lining. In that study, published in 2013, Karp, Langer, Yin, and others reported that they could generate large quantities of immature intestinal cells and then stimulate them to differentiate, by exposing them to certain molecules.

During that study, the team became aware that cells that provide structural support in the cochlea express some of the same surface proteins as intestinal stem cells. The researchers decided to explore whether the same approach would work in those supporting cells.

They exposed cells from a mouse cochlea, grown in a lab dish, to molecules that stimulate the Wnt pathway, which makes the cells multiply rapidly.

"We used small molecules to activate the supporting cells so they become proliferative and can generate hair cells," Yin says.

At the same time, to prevent the cells from differentiating too soon, the researchers also exposed the cells to molecules that activate another signaling pathway known as Notch.

Once they had a large pool of immature progenitor cells (about 2,000-fold greater than any previously reported), the researchers added another set of molecules that provoked the cells to differentiate into mature hair cells. This procedure generates about 60 times more mature hair cells than the technique that had previously worked the best, which uses growth factors to induce the supporting cochlea cells to become hair cells without first expanding the population.

The researchers found that their new approach also worked in an intact mouse cochlea removed from the body. In that experiment, the researchers did not need to add the second set of drugs because once the progenitor cells were formed, they were naturally exposed to signals that stimulated them to become mature hair cells.

"We only need to promote the proliferation of these supporting cells, and then the natural signaling cascade that exists in the body will drive a portion of those cells to become hair cells," Karp says.

Easy administration

Because this treatment involves a simple drug exposure, the researchers believe it could be easy to administer it to human patients. They envision that the drugs could be injected into the middle ear, from which they would diffuse across a membrane into the inner ear. This type of injection is commonly performed to treat ear infections.

Some of the researchers have started a company called Frequency Therapeutics, which has licensed the MIT/BWH technology and plans to begin testing it in human patients within 18 months. "We hope that our work will allow other scientists to pursue studies of supporting cells and hair cells that have not been possible because such limited quantities of hair cells were available," Will McLean says.

"Researchers who have been eager to conduct experiments on inner ear hair cells will now be able to replicate our work and have huge numbers of them to do all kinds of experiments," Karp says.

Karp, Langer, and Yin are also working on applying this approach to other types of cells, including types of intestinal cells involved in insulin regulation and control of the gut microbiota.
-end-
The research was funded by the National Institutes of Health, the European Commission, the Harvard-MIT IDEA2 Award, the Shulsky Foundation, David H. Koch, and Robert Boucai.

Massachusetts Institute of Technology

Related Hearing Loss Articles:

Researchers listen to zebrafish to understand human hearing loss
Can a fish with a malformed jaw tell us something about hearing loss in mice and humans?
Postmenopausal hormone therapy associated with higher risk of hearing loss
Use of postmenopausal hormone therapy was associated with higher risk of hearing loss, and the risk tended to increase with longer duration of use.
Few researchers consider hearing loss in healthcare communication: Study
Of the 67 papers reviewed, only 16 (23.9 percent) included any mention of hearing loss.
Few studies consider hearing loss when assessing communication with physicians
Doctors believe that communication with those under their care is important, but most studies of communication between physicians and older adults do not mention that hearing loss may affect this interaction.
Study shows hearing tests miss common form of hearing loss
Traditional clinical hearing tests often fail to diagnose patients with a common form of inner ear damage that might otherwise be detected by more challenging behavioral tests, according to the findings of a University at Buffalo-led study published in the journal Frontiers in Neuroscience.
Drug treatment could combat hearing loss
Researchers at MIT and Brigham and Women's Hospital have discovered a combination of drugs that induces supporting cells in the ear to differentiate into hair cells, offering a potential new way to treat hearing loss.
Second cause of hidden hearing loss identified
Some people can pass a hearing test but have trouble understanding speech in a noisy environment.
U study: Law aiding infants at risk for hearing loss
A Utah law has led to increased early identification of infants with hearing loss due to a congenital infection, according to a new study by University of Utah and Utah Department of Health researchers.
MED-EL convenes global hearing researchers for age-related hearing loss workshop
Leading scientists and hearing experts from around the world will gather for a scientific workshop sponsored by hearing implant leader MED-EL.
Iron deficiency anemia associated with hearing loss
In a study published online by JAMA Otolaryngology-Head & Neck Surgery, Kathleen M.

Related Hearing Loss Reading:

Hearing Loss: Facts and Fiction: 7 Secrets to Better Hearing
by Timothy Frantz M.D. (Author)

"Hearing Loss – Facts and Fiction- 7 SECRETS TO BETTER HEARING" is the solution to the American epidemic of hearing loss. One in five Americans suffer from hearing loss. Unfortunately up to 3/4 of Americans with hearing loss do not treat it, primarily due to the high cost of hearing aids. "The Hear Doc" is concerned about what he considers to be a true crisis. In this easy-to-read book, Dr. Frantz shows you: -12 Ways to get Hearing Aids for FREE or at Reduced Prices. -10 Tips to Better Communication Without Using Hearing Aids. -How to Try Hearing Aids at NO Risk in Over 30 U.S.... View Details


Hearing Loss: A Guide to Prevention and Treatment (Harvard Medical School Special Health Reports)
by Harvard Health Publications (Author), Harvard Health Publications (Editor), David Murray Vernick (Editor), Ann Stockwell (Editor)

If you thing you might need a hearing checkup, you probably do. This special health report describes the causes and cures for hearing loss. You ll learn about the latest advances in hearing aid technology and find out which kind of hearing device may be best for you. This report also contains in-depth information on the causes, diagnosis, and treatment of hearing loss. You'll learn how to prevent hearing loss and preserve the hearing you have now. View Details


The Hearing-Loss Guide: Useful Information and Advice for Patients and Families (Yale University Press Health & Wellness)
by John M. Burkey (Author), Robert L. Daniels (Foreword)

The best advice for those with hearing loss, from a leading audiologist and from patients with personal experience  

Where can the most accurate and helpful information about hearing loss be found? From a friend or relative who has impaired hearing? From an experienced audiologist? Both, says the author of this essential book!
 
In an unusual new approach, audiologist John M. Burkey offers not only specific and up-to-date information based on his own extensive experience with patients, but also useful, first-hand advice from those patients themselves. The... View Details


Frustrated by Hearing Loss? Five Keys to Communication Success
by Dusty Ann Jessen Au.D. (Author)

Let's face it...hearing loss is incredibly frustrating for all parties involved. Hearing aids have come a long way in recent years, but they are only one piece of the communication puzzle. To conquer communication breakdowns, it is essential to learn the 5 Keys to Communication Success! View Details


Hearing Loss: Causes, Prevention, and Treatment
by Jos J. Eggermont (Author)

Hearing Loss: Causes, Prevention, and Treatment covers hearing loss, causes and prevention, treatments, and future directions in the field, also looking at the cognitive problems that can develop.

To avoid the “silent epidemic” of hearing loss, it is necessary to promote early screening, use hearing protection, and change public attitudes toward noise. Successful treatments of hearing loss deal with restoring hearing sensitivity via hearing aids, including cochlear, brainstem, or midbrain implants. Both the technical aspects and effects on the quality of life of these... View Details


Understanding Childhood Hearing Loss: Whole Family Approaches to Living and Thriving (Whole Family Approaches to Childhood Illnesses and Disorders)
by Brian J. Fligor (Author)

Childhood hearing loss is more common than most people assume, and yet this invisible condition can rob a child of the ability to develop close emotional relationships with family and friends. This book demystifies this condition and offers emotionally-supportive approaches to caring for the child and the whole family. It is written from the perspective of a pediatric audiologist who has diagnosed hearing loss in hundreds of newborns and young children, and who has shaped clinical best-practices during his career.

Hearing loss is not an “all or nothing” condition, but a range... View Details


What Did You Say? An Unexpected Journey Into the World of Hearing Loss
by Monique E. Hammond (Author)

Nothing prepared Monique Hammond for her own sudden hearing loss, and her questions to medical professionals often left her with more questions than answers. What Did You Say? is the book she wishes she had when she was coping with and trying to understand her own hearing loss.

Hammond points out that she is not a professional hearing specialist, so her first important message is that people who experience any ear-related symptoms ''must consult their physician or ear specialist for proper diagnosis and treatment.'' From there, she provides organized, easy-to-understand facts and... View Details


Hearing Loss: From Stigma to Strategy
by Michael Simmons (Author)

Literally millions of people in Britain are affected by hearing loss, and the number is growing steadily. For many, it is a desperate situation, for others, an unwished-for challenge: to enter the world of hearing aids and gadgets, and to somehow come to terms with other people’s jokes—blindness is never laughed at—and the need to adjust a muffled, or even silent, environment. Michael Simmons, a distinguished international journalist until his retirement in 1997, has age-related hearing loss. Researching for this book, he soon realized it was a very poor relation in the deafness field.... View Details


The Consumer Handbook on Hearing Loss and Hearing Aids: A Bridge to Healing
by Richard E. Carmen (Editor)

This Fourth Edition is updated to current knowledge and technology that includes fascinating and compelling new information on cutting edge fitness-related research and better hearing. The collective effort of all the writers covers about everything you'll want to know if you have a hearing loss and are considering hearing aids. There can be a lot of uncertainty and emotions that prevail during the process of addressing untreated hearing loss, leaving a trail of devastation and turmoil in its wake, since procrastination is often at the expense of loved ones.This book charts a quiet path... View Details

Best Science Podcasts 2017

We have hand picked the best science podcasts for 2017. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Simple Solutions
Sometimes, the best solutions to complex problems are simple. But simple doesn't always mean easy. This hour, TED speakers describe the innovation and hard work that goes into achieving simplicity. Guests include designer Mileha Soneji, chef Sam Kass, sleep researcher Wendy Troxel, public health advocate Myriam Sidibe, and engineer Amos Winter.
Now Playing: Science for the People

#448 Pavlov (Rebroadcast)
This week, we're learning about the life and work of a groundbreaking physiologist whose work on learning and instinct is familiar worldwide, and almost universally misunderstood. We'll spend the hour with Daniel Todes, Ph.D, Professor of History of Medicine at The Johns Hopkins University, discussing his book "Ivan Pavlov: A Russian Life in Science."