Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetic hearing loss may be reversible without gene therapy

26.02.2007
A large proportion of genetically caused deafness in humans may be reversible by compensating for a missing protein, based on discoveries in mice.

Emory University researchers have found that in mice, increasing the amount of the protein connexin26 in the ear's cochlea compensates for an absence of another protein, connexin30. The findings come 10 years after scientists first discovered that connexin26 mutations cause much of the deafness diagnosed at birth.

Xi (Erick) Lin, PhD, associate professor of otolaryngology and cell biology at Emory University School of Medicine, was lead author of the study, published recently in the Proceedings of the National Academy of Sciences (http://www.pnas.org/cgi/content/full/104/4/1337).

"There are millions of deaf people affected by mutations in this one gene, connexin26," he says. "Congenital hearing loss is one of the most common human genetic birth defects, and that is why in almost all the states universal newborn hearing screening is mandated by law [including Georgia]."

... more about:
»connexin26 »connexin30 »deafness »junction »therapy

In people without congenital hearing loss, connexin26 and connexin30 work together to form the cochlea's hybrid junction gaps, which facilitate intercellular communication. But when one of the proteins is missing, the hybrid junction gaps fail to work, and the cochlea's hair cells die off, leaving the body incapable of translating sounds into nerve impulses.

Even though scientists knew connexin26 was implicated in congenital deafness, they did not know precisely why. Working with Emory colleagues and scientists from the University of Bonn in Germany, Dr. Lin developed contrasting hypotheses.

"The deafness could have two very different explanations," he says. "Either hybrid gap junctions have special biophysical properties that cannot be replaced by gap junctions built with only one type of connexin, or mutations in one of the two connexins just cut the supply for making the gap junctions in half."

By adding extra connexin26 to mice that were missing connexin30, Dr. Lin and his team proved the latter hypothesis. With the additional connexin26, hearing sensitivity was restored and the expected hair cell death never occurred. Those positive findings led Dr. Lin to conclude, "The problem is simply caused by not having enough protein remaining in the ear of these mutant mice to assemble gap junctions."

Dr. Lin and his colleagues are now working to see if connexin-related deafness can be reversed in a mouse model, or if increasing connexin30 may help when connexin26 is absent.

As the research picks up momentum, these results--and future findings--may mean big changes for how congenital deafness is approached. Up to now, says Dr. Lin, scientists working on hearing loss had placed all their bets on gene therapy. That may no longer make sense. "Gene therapy, which has very few successful cases so far, may not be necessary," explains Dr. Lin.

Instead, Dr. Lin's findings indicate that a drug to boost connexin26 may be all that is needed. "Our work predicts that a drug should be sufficient to cure connexin30 deletion-caused deafness," he says.

Holly Korschun | EurekAlert!
Further information:
http://www.emory.edu
http://www.pnas.org/cgi/content/full/104/4/1337

Further reports about: connexin26 connexin30 deafness junction therapy

More articles from Life Sciences:

nachricht First study on physical properties of giant cancer cells may inform new treatments
14.08.2018 | Brown University

nachricht Tiny Helpers that Clean Cells
14.08.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

Tiny Helpers that Clean Cells

14.08.2018 | Life Sciences

Algorithm provides early warning system for tracking groundwater contamination

14.08.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>