Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

U Iowa researchers prevent hereditary deafness in mice

28.07.2005


Working with mice, University of Iowa scientists and colleagues from Okayama University, Japan, have shown that it is possible to cure a certain type of hereditary deafness by silencing a gene that causes hearing loss.



Richard Smith, M.D., the Sterba Hearing Research Professor in Otolaryngology at the UI Roy J. and Lucille A. Carver College of Medicine, described the study as a proof-of-principle experiment, but added that the success may point the way to new treatments for deafness in humans.

"We gave a genetically-deafened mouse interfering RNA that specifically prevents a gene from being expressed that would otherwise cause deafness. By preventing its expression, we prevented the deafness," said Smith who was senior author of the study. "Even though this is in the early stages, it is really exciting because it points to other options for people who have hearing loss other than hearing aids or cochlear implants."


The gene-silencing technique used by the UI team is called RNA interference (RNAi) and works specifically against genetic conditions caused by a so-called dominant negative mechanism -- when a single copy of the mutant gene is sufficient to cause disease because the protein from the faulty gene has a dominant adverse effect over the protein from the normal gene. Although many of the most common deafness genes do not work through this mechanism, several human forms of inherited deafness, including the one mimicked by the UI mouse model, are caused by a dominant negative mechanism.

To test the gene-silencing technique, Yukihide Maeda, M.D., Ph.D., a postdoctoral researcher in Smith’s lab and lead author of the study, introduced a mutated gene that causes deafness in humans into the inner ear of mice. This gene acted through a dominant negative mechanism, and the mice had moderate hearing loss. Next, Maeda simultaneously introduced the mutant gene and a short piece of interfering RNA specifically designed to silence the gene. Standard hearing tests, similar to those used on newborn babies, confirmed that the treated mice were able to hear.

Smith noted that RNA interference was not only successful but also highly specific. Despite the fact that the mouse and the human gene differed by only two nucleotides over the short stretch of gene targeted by the RNAi, the mutant human gene was silenced while the normal mouse gene was unaffected.

With a view to someday moving this therapy to humans, the researchers also developed a non-invasive strategy to deliver the RNAi. A small piece of foam soaked in a solution containing the interfering RNA was placed against the membrane covering one opening into the inner ear of the mice. The slightly porous membrane allowed the interfering RNA to diffuse into the inner ear cells.

Although the UI team was successful in curing the mice of their genetic deafness, and the delivery strategy should translate easily to humans, a number of issues still must be addressed before the technique can be considered as a potential human therapy. These hurdles include determining if the treatment will still work in a mouse that has been deaf for some time before the RNAi is delivered, and finding ways to sustain the gene-silencing effect over an extended period of time.

Smith added that developing the technique to produce long-term rescue of hearing loss is a future focus for his research team.

In addition to Smith and Maeda, the research team included Kunihiro Fukushima and Kazunori Nishizaki of Okayama University Graduate School of Medicine in Okayama, Japan. The study, which was published in the June 15 issue of Human Molecular Genetics, was funded by the National Institutes of Health.

Jennifer Brown | EurekAlert!
Further information:
http://www.uiowa.edu

More articles from Life Sciences:

nachricht The dense vessel network regulates formation of thrombocytes in the bone marrow
25.07.2017 | Rudolf-Virchow-Zentrum für Experimentelle Biomedizin der Universität Würzburg

nachricht Fungi that evolved to eat wood offer new biomass conversion tool
25.07.2017 | University of Massachusetts at Amherst

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>