Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene regulator is key to healthy retinal development and good vision in adulthood

09.08.2013
Animal study reveals “unexpected” role of horizontal cells in photoreceptor rod and cone cell development of retina

Scientists are developing a clearer picture of how visual systems develop in mammals. The findings offer important clues to the origin of retinal disorders later in life.


Confocal microscope images show far fewer horizontal cells generated in mice without Onecut1 (bottom panels) compared to those in normal mice (top panels).

In research published this week in the Journal of Neuroscience, University at Buffalo scientists and colleagues focused on a particular protein, called a transcription factor, that regulates gene activity necessary for the development of one type of retinal neuron, the horizontal cells.

Horizontal cells process visual information by integrating and regulating input from rod and cone photoreceptors, which allow eyes to adjust to see well in both bright and dim light conditions.

“We have found that activation of the transcription factor named Onecut1 is essential for the formation of horizontal cells,” explains Xiuqian Mu, PhD, assistant professor in the departments of Ophthalmology and Biochemistry in the UB School of Medicine and Biomedical Sciences.

The researchers came to this conclusion after creating mice that lacked Onecut1. In these knockout mice, the number of horizontal cells was 80 percent lower than in normal mice.

The researchers were surprised to find that the removal of Onecut1 also had an impact on photoreceptor cells, the rods and cones that absorb light in the retina and convert that energy to an electrical impulse eventually conveyed to the brain.

During development, Mu explains, the removal of Onecut1 only appeared to impact the horizontal cells. However, by the time these mice reached adulthood, around 8 months old, the level of photoreceptor cells in these knockout mice was less than half the normal level.

“Because degradation of photoreceptors is believed to be a major factor in retinal diseases, such as retinitis pigmentosa and Leber’s congenital amaurosis, this finding, that horizontal cells are necessary for the normal survival of photoreceptor cells, is novel and significant,” says Mu. “Many retinal diseases are manifested by the degeneration of photoreceptor cells.”

This finding was unexpected, Mu explains, because most investigations into the degeneration of photoreceptor cells have involved genes that directly affect photoreceptor cell development.

“People haven’t been looking at horizontal cells,” he says. “We didn’t think that they’d be involved in photoreceptor cell degradation.

“With this finding, we have discovered that retinal horizontal cells are required for maintaining the integrity of the retina and that their deficiency can lead to retinal degradation,” explains Mu.

He notes that in most cases where photoreceptor cells die, it’s because they are somehow defective.

“But in this case, the photoreceptor cells are fine in the beginning, so the death of the photoreceptor cells is a secondary affair that is somehow driven by the deficiency in horizontal cells,” he says.

UB co-author Steven J. Fliesler, PhD, Meyer H. Riwchun Endowed Chair Professor, vice-chair and director of research in the Department of Ophthalmology and professor in the Department of Biochemistry, notes that this finding could open up a new area of study.

“One scenario we have speculated upon is that there are important supportive interactions between horizontal cells and photoreceptors that are required to maintain photoreceptor function and viability,” Fliesler says. “When horizontal cells are blocked from being formed -- the immediate consequence of knocking out Onecut1 -- the photoreceptors don't get what they need to survive, so they degenerate and die later on.”

The majority of the research was conducted in the UB Department of Ophthalmology/Ross Eye Institute and the developmental genomics group at UB’s New York State Center of Excellence in Bioinformatics and Life Sciences.

First author on the paper is Fuguo Wu of UB. Other UB co-authors are Renzhong Li, Tadeusz J. Kaczynski, Darshan Sapkota. Additional co-authors are Yumiko Umino and Eduardo Solessio of SUNY Upstate Medical University, Shengguo Li and Mengqing Xiang of the University of Medicine and Dentistry of New Jersey, David M. Sherry of the University of Oklahoma Health Sciences Center and Maureen Gannon of Vanderbilt University Medical Center.

Mu, Fliesler and Solessio also are faculty members of the SUNY Eye Institute, a SUNY-wide eye research consortium.

The work was supported by the Whitehall Foundation, the National Eye Institute, the SUNY/RF Research Collaboration Fund, Research to Prevent Blindness, the Oklahoma Center for the Advancement of Science and Technology, the Lions of Central New York, and resources and facilities provided by the Veterans Administration Western NY Healthcare System.

Media Contact Information
Ellen Goldbaum
Senior Editor, Medicine
Tel: 716-645-4605
goldbaum@buffalo.edu
Twitter: @egoldbaum

Ellen Goldbaum | EurekAlert!
Further information:
http://www.buffalo.edu

More articles from Life Sciences:

nachricht Toward a 'smart' patch that automatically delivers insulin when needed
18.01.2017 | American Chemical Society

nachricht 127 at one blow...
18.01.2017 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>