Featured Research

from universities, journals, and other organizations

Discovering the missing 'LINC' to deafness

Date:
January 28, 2013
Source:
American Friends of Tel Aviv University
Summary:
50 percent of hearing loss is linked to genetic mutations. Now a researcher has discovered a significant mutation in a family of proteins that could lead to new treatments for hearing disorders.

The different position of cell nuclei in unhealthy (red) cells relative to healthy (blue) cells leads to deafness.
Credit: Image courtesy of American Friends of Tel Aviv University

Because half of all instances of hearing loss are linked to genetic mutations, advanced gene research is an invaluable tool for uncovering causes of deafness -- and one of the biggest hopes for the development of new therapies. Now Prof. Karen Avraham of the Sackler Faculty of Medicine at Tel Aviv University has discovered a significant mutation in a LINC family protein -- part of the cells of the inner ear -- that could lead to new treatments for hearing disorders.

Her team of researchers, including Dr. Henning Horn and Profs. Colin Stewart and Brian Burke of the Institute of Medical Biology at A*STAR in Singapore, discovered that the mutation causes chaos in a cell's anatomy. The cell nucleus, which contains our entire DNA, moves to the top of the cell rather than being anchored to the bottom, its normal place. Though this has little impact on the functioning of most of the body's cells, it's devastating for the cells responsible for hearing, explains Prof. Avraham. "The position of the nucleus is important for receiving the electrical signals that determine proper hearing," she explains. "Without the ability to receive these signals correctly, the entire cascade of hearing fails."

This discovery, recently reported in the Journal of Clinical Investigation, may be a starting point for the development of new therapies. In the meantime, the research could lead towards work on a drug that is able to mimic the mutated protein's anchoring function, and restore hearing in some cases, she suggests.

From human to lab to mouse

Prof. Avraham originally uncovered the genetic mutation while attempting to explain the cause of deafness in two families of Iraqi Jewish descent. For generations, members of these families had been suffering from hearing loss, but the medical cause remained a mystery. Using deep genetic sequencing, a technology used to sequence the entire human genome, she discovered that the hearing impaired members of both families had a mutated version of the protein Nesprin4, a part of the LINC group of proteins that links the cell's nucleus to the inner wall of the cell.

In the lab, Prof. Avraham recreated this phenomenon by engineering the mutation in single cells. With the mutation in place, Nesprin4 was not found in the area around the cell nucleus, as in healthy cells, but was spread throughout the entire cell. Investigating further, she studied lab mice that were engineered to be completely devoid of the protein.

Created in Singapore, the mice were originally engineered to study the biology of LINC proteins. The fact that they were deaf came as a complete surprise to researchers. Without this protein serving as an anchor, the cell nucleus is not located in the correct position within inner ear cells, but seems to float throughout. This causes the cells' other components to reorient as well, ultimately harming the polarity of the cells and hindering electrical signals. It's a mutation that took a heavy toll on the cells' ability to transfer sound signals, explains Prof. Avraham, rendering the mice deaf.

Given the similarity between mouse and human inner ear cells, researchers predict that the same phenomenon is occurring in human patients with a mutation in the Nesprin4 gene.

Looking for a wider impact

Prof. Avraham says that she and her collaborators are the first to reveal this mutation as a cause of deafness. "Now that we have reported it, scientists around the world can test for mutations in this gene," she notes. The mutation could indeed be a more common genetic cause of deafness in a number of populations. And because Nesprin4 belongs to a family of proteins that have been linked to other diseases, such as muscular coordination and degeneration disorders, this could prove a ripe area for further research.


Story Source:

The above story is based on materials provided by American Friends of Tel Aviv University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Henning F. Horn, Zippora Brownstein, Danielle R. Lenz, Shaked Shivatzki, Amiel A. Dror, Orit Dagan-Rosenfeld, Lilach M. Friedman, Kyle J. Roux, Serguei Kozlov, Kuan-Teh Jeang, Moshe Frydman, Brian Burke, Colin L. Stewart, Karen B. Avraham. The LINC complex is essential for hearing. Journal of Clinical Investigation, 2013; DOI: 10.1172/JCI66911

Cite This Page:

American Friends of Tel Aviv University. "Discovering the missing 'LINC' to deafness." ScienceDaily. ScienceDaily, 28 January 2013. <www.sciencedaily.com/releases/2013/01/130128113926.htm>.
American Friends of Tel Aviv University. (2013, January 28). Discovering the missing 'LINC' to deafness. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2013/01/130128113926.htm
American Friends of Tel Aviv University. "Discovering the missing 'LINC' to deafness." ScienceDaily. www.sciencedaily.com/releases/2013/01/130128113926.htm (accessed August 22, 2014).

Share This




More Health & Medicine News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Two US Ebola Patients Leave Hospital Free of the Disease

Two US Ebola Patients Leave Hospital Free of the Disease

AFP (Aug. 21, 2014) Two American missionaries who were sickened with Ebola while working in Liberia and were treated with an experimental drug are doing better and have left the hospital, doctors say on August 21, 2014. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Cadavers, a Teen, and a Medical School Dream

Cadavers, a Teen, and a Medical School Dream

AP (Aug. 21, 2014) Contains graphic content. He's only 17. But Johntrell Bowles has wanted to be a doctor from a young age, despite the odds against him. He was recently the youngest participant in a cadaver program at the Indiana University NW medical school. (Aug. 21) Video provided by AP
Powered by NewsLook.com
American Ebola Patients Released: What Cured Them?

American Ebola Patients Released: What Cured Them?

Newsy (Aug. 21, 2014) It's unclear whether the American Ebola patients' recoveries can be attributed to an experimental drug or early detection and good medical care. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins