(Press-News.org) Researchers at the University of Minnesota Medical School have gained insight into how different types of age-related hearing loss may occur in humans. The discovery could eventually help physicians develop drugs to combat progressive hearing loss. Their paper is published on October 14 in the open-access journal PLoS Genetics.
James Ervasti, Ph.D., and colleague Ben Perrin, Ph.D., studied how two very closely related genes contribute to hearing function in mice. Mutations in the same genes are associated with deafness in humans. The duo discovered two key cellular processes that are required to maintain auditory function.
The genes encode proteins called β-actin and γ-actin. In humans, deafness-causing mutations have been linked to both proteins. β- and γ-actin comprise the primary structural elements of stereocilia (hair-like fibers in the ear), which convert mechanical sound energy into the nerve signals that allow humans to hear.
The two proteins are 99 percent identical; however, their slight differences have been exactly conserved through evolution from birds to mammals, suggesting that each protein may have important and distinct functions. Ervasti and Perrin tested the idea that two closely linked proteins have separate, but important, roles in hearing by knocking out each gene in mouse auditory hair cells.
They found that β-actin and γ-actin do have different maintenance functions that together keep the hair-like fibers -- that allow mice to hear -- healthy. Both knockout mice had normal hearing at young ages, but developed specific types of progressive hearing loss and stereocilia pathology that differed depending on which protein was lost.
"These separate maintenance pathways are likely important for maintaining auditory function during aging and may contribute to future understanding of common forms of age-related hearing loss in humans," Perrin said.
INFORMATION:
FINANCIAL DISCLOSURE: Funding was provided by NIH grants F32 DC009539 (to BJP) and a R01 AR049899 (to JME). Parts of this work were carried out in the Characterization Facility, University of Minnesota, a member of the NSF-funded Materials Research Facilities Network (www.mrfn.org) via the MRSEC program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
COMPETING INTERESTS: The authors have declared that no competing interests exist.
CITATION: Perrin BJ, Sonnemann KJ, Ervasti JM (2010) b-Actin and c-Actin Are Each Dispensable for Auditory Hair Cell Development But Required for Stereocilia Maintenance. PLoS Genet 6(10): e1001158. doi:10.1371/journal.pgen.1001158
PLEASE ADD THIS LINK TO THE FREELY AVAILABLE ARTICLE IN ONLINE VERSIONS OF YOUR REPORT (the link will go live when the embargo ends): http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1001158
PRESS-ONLY PREVIEW OF THE ARTICLE:
http://www.plos.org/press/plge-06-10-ervasti.pdf
CONTACT: Nick Hanson, Academic Health Center, 612-624-2449, hans2853@umn.edu
Justin Paquette, Academic Health Center, 612-626-7037, jpaquett@umn.edu
Disclaimer
This press release refers to an upcoming article in PLoS Genetics. The release is provided by journal staff [or by the article authors and/or their institutions. Any opinions expressed in this release or article are the personal views of the journal staff and/or article contributors, and do not necessarily represent the views or policies of PLoS. PLoS expressly disclaims any and all warranties and liability in connection with the information found in the releases and articles and your use of such information.
About PLoS Genetics
PLoS Genetics (http://www.plosgenetics.org) reflects the full breadth and interdisciplinary nature of genetics and genomics research by publishing outstanding original contributions in all areas of biology. All works published in PLoS Genetics are open access. Everything is immediately and freely available online throughout the world subject only to the condition that the original authorship and source are properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.
About the Public Library of Science
The Public Library of Science (PLoS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org.
END
1. One-Size-Fits-All Blood Pressure Recommendations Won't Suit All Dialysis Patients
Age, Race, and Diabetes Status Affect Blood Pressure's Link to Premature Death
Previous research indicates that mild to moderate hypertension may not increase dialysis patients' risk of dying prematurely. These findings contrast with those found in the general population and are generalized to diverse groups of patients with kidney disease. To see if age, race, and the presence or absence of diabetes affects the relationship between blood pressure and risk of premature death among dialysis ...
Dramatic flares and bursts of energy - activity previously thought reserved for only the strongest magnetized pulsars - has been observed emanating from a weakly magnetised, slowly rotating pulsar. The international team of astrophysicists who made the discovery believe that the source of the pulsar's power may be hidden deep within its surface.
Pulsars, or neutron stars, are the collapsed remains of massive stars. Although they are on average only about 30km in diameter, they have hugely powerful surface magnetic fields, billions of times that of our Sun.
The most ...
Rivers and streams supply the lifeblood of ecosystems across the globe, providing water for drinking and irrigation for humans as well as a wide array of life forms in rivers and streams from single-celled organisms all the way up to the fish humans eat. But humans and nature itself are making it tough on rivers to continue in their central role to support fish species, according to new research by a team of scientists including one from Arizona State University.
Globally, rivers and streams are being drained due to human use and climate change. These and other human ...
Although most people assume that tests are a way to evaluate learning, a wealth of research has shown that testing can actually improve learning, according to two researchers from Kent State University. Dr. Katherine Rawson, associate professor in Kent State's Department of Psychology, and former Kent State graduate student Mary Pyc publish their research findings in the Oct. 15, 2010, issue of the journal Science.
"Taking practice tests – particularly ones that involve attempting to recall something from memory – can drastically increase the likelihood that you'll be ...
The food chain - the number of organisms that feed on each other — in the world's streams and rivers depends more upon the size of the stream and whether the waterways flood or run dry than the amount of available food resources, Yale University and Arizona State University (ASU) researchers report online in the Oct. 14 issue of the journal Science Express.
The findings suggest that large predators in river systems will be threatened by increased variability in water flow induced by climate change. The research also helps settle an old debate among ecologists about ...
While not an outright failure, a 2010 goal set by the Convention on Biological Diversity (CBD) for staunching the loss of the world's species fell far short of expectations for "The International Year of Biodiversity."
What does this mean for the 20 proposed 2020 goals being considered by the 10th conference of parties at the Convention on Biological Diversity in Nagoya, Japan, on Oct. 18-29, 2010?
In the article "Ecosystem Services for 2020," published Oct. 15, 2010 in the journal Science, some of the world's foremost biodiversity experts assembled by the Paris-based ...
Researchers have developed a genetic tool in mice to speed the discovery of novel genes involved in cancer. The system – called PiggyBac – has already been used by the team to identify novel candidate cancer-causing genes.
This new development of the PiggyBac system makes it a powerful addition to the armoury of genetic methods available to researchers for picking apart the genetic causes of cancer. It will complement advances in genomics and genetics of cancer, by providing biological validation to human mutations identified by cancer genome sequencing.
The PiggyBac ...
A gene's location on a chromosome plays a significant role in shaping how an organism's traits vary and evolve, according to findings by genome biologists at New York University's Center for Genomic and Systems Biology and Princeton University's Lewis-Sigler Institute for Integrative Genomics. Their research, which appears in the latest issue of the journal Science, suggests that evolution is less a function of what a physical trait is and more a result of where the genes that affect that trait reside in the genome.
Physical traits found in nature, such as height or eye ...
Discovery of a molecular switch that turns off the natural process of skin pigmentation may lead to a novel way of protecting the skin – activating the tanning process without exposure to cancer-causing UV radiation. In their report in the journal Genes & Development, researchers from the Massachusetts General Hospital (MGH) Cutaneous Biology Research Center (CBRC) describe how blocking the action of this switch – an enzyme called PDE-4D3 – in the skin of mice led to a significant increase in melanin production.
"The primary goal of inducing melanin production in human ...
AUDIO:
When a person has a heart attack, and the heart stops beating, a new study led by researchers at Washington University School of Medicine in St. Louis suggests that the...
Click here for more information.
Heart attack patients whose hearts have stopped beating and who receive cardiopulmonary resuscitation (CPR) from bystanders fare better if their resuscitators skip the rescue breaths and do only chest compression, according to a study led by researchers at Washington ...
