Navigation Links
Gene therapy restores vision to mice with retinal degeneration
Date:10/16/2008

Massachusetts General Hospital (MGH) researchers have used gene therapy to restore useful vision to mice with degeneration of the light-sensing retinal rods and cones, a common cause of human blindness. Their report, appearing in the Oct. 14 Proceedings of the National Academy of Sciences, describes the effects of broadly expressing a light-sensitive protein in other neuronal cells found throughout the retina.

"This is a proof of principle that someday we may be able to repair blindness in people with conditions like retinitis pigmentosa and macular degeneration," says Richard Masland, PhD, director of the Cellular Neurobiology Laboratory in the MGH Department of Neurosurgery. "There are several limitations we need to overcome before we can begin clinical trials, but I'm optimistic that this work may someday make a big difference for people who otherwise would have no vision at all."

The study was designed to investigate the effect of expressing the light-sensitive protein melanopsin in retinal ganglion cells. These specialized neurons receive light signals from the rods and cones and carry those signals into the brain via the optic nerve, which is formed from the cells' axons. Melanopsin is usually produced in a subset of cells that are involved with establishing circadian rhythms but not with vision. The MGH team used the standard viral vector adeno-associated virus to deliver the gene encoding melanopsin throughout the retinas of mice whose rod and cone photoreceptors had degenerated from lack of a crucial protein.

Four weeks after delivery of the gene, melanopsin normally produced in 1 percent of retinal ganglion cells was found in about 10 percent of ganglion cells in the treated eyes but not in eyes that received a sham injection. Many of the melanopsin-expressing cells were structurally different from those that typically produce the protein, implying that it was being expressed in a broader range of retinal ganglion cells. Electrophysiological examination of the melanopsin-expressing cells revealed that all responded to light, although the neuronal signal was delayed and persisted after the light signal had stopped, which is typical for a melanopsin-mediated signal. Two behavioral tests verified that the treated mice which otherwise would have been essentially blind had enough vision to find a darkened refuge in an otherwise brightly-lit area and to successfully learn that a light indicated a safe platform to which they could swim.

"The same level of melanopsin expression in a human retina might allow someone who otherwise would be totally blind to read newspaper headlines, but the slowness of the response would be a problem," Masland says. He notes that another group's gene therapy experiments published earlier this year were similar but used a protein that requires a level of light comparable to looking directly into a bright sky for a whole day, which would eventually damage the retina. "Before planning clinical trials, we need to develop a more sensitive version of the other protein, channelrhodopsin-2, or a faster-responding melanopsin, which we are working on."


'/>"/>

Contact: Sue McGreevey
smcgreevey@partners.org
617-724-2764
Massachusetts General Hospital
Source:Eurekalert

Related biology news :

1. A new radiation therapy treatment developed for head and neck cancer patients
2. St. Jude finds factors that accelerate resistance to targeted therapy in lymphoblastic leukemia
3. UC health news: molecular pathway may predict chemotherapy effectiveness
4. MIT works toward safer gene therapy
5. Intravenous gene therapy protects normal tissue of mice during whole-body radiation
6. Gene, stem cell therapy only needs to be 50 percent effective to create a healthy heart
7. Fourth Annual International Conference on Cell Therapy for Cardiovascular Diseases
8. Safe and effective therapy discovered for patients with protein-losing enteropathy
9. Ireland Cancer Center researchers advance stem cell gene therapy
10. Dolphin therapy a dangerous fad, Emory researchers warn
11. Cancer and arthritis therapy may be promising treatment for diabetes
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/13/2017)... 13, 2017 UBM,s Advanced Design and Manufacturing ... feature emerging and evolving technology through its 3D Printing ... run alongside the expo portion of the event and ... demonstrations focused on trending topics within 3D printing and ... manufacturing event will take place June 13-15, 2017 at the ...
(Date:4/11/2017)... Research and Markets has announced the addition of the ... ... to grow at a CAGR of 30.37% during the period 2017-2021. ... been prepared based on an in-depth market analysis with inputs from ... prospects over the coming years. The report also includes a discussion ...
(Date:4/6/2017)... 2017 Forecasts by Product Type ... by End-Use (Transportation & Logistics, Government & Public Sector, ... Fossil Generation Facility, Nuclear Power), Industrial, Retail, Business Organisation ... Are you looking for a definitive report on the ... ...
Breaking Biology News(10 mins):
(Date:8/10/2017)... , ... August 09, 2017 , ... ... help the agriculture industry reach its ideal customers with the right message. Their ... , “As a Midwest company, we realize how crucial the agriculture industry is,” ...
(Date:8/10/2017)... Ca (PRWEB) , ... August 09, 2017 , ... ... for regenerative medicine applications in the clinic is here. The team at Capricor ... present in conditioned medium for clinical studies. , Dr. Travis Antes, head ...
(Date:8/10/2017)... ... August 09, 2017 , ... Okyanos Center for Regenerative Medicine ... the Pelican Bay Hotel in Freeport, Grand Bahama on September 27, 2017. This daytime ... , With oversight from the Ministry of Health’s National Stem Cell Ethics Committee (NSCEC) ...
(Date:8/10/2017)... Philadelphia PA and London UK (PRWEB) , ... August 10, 2017 ... ... (SCRS) will host a new educational webinar to demonstrate how Good ... on feasibility, contracts, and site documents. In addition the webinar will discuss the importance ...
Breaking Biology Technology: