Navigation Links
Gene therapy restores vision to mice with retinal degeneration

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
Massachusetts General Hospital

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:
(Date:5/12/2016)... 2016 , a brand of ... results from the Q1 wave of its quarterly wearables ... consumers, receptivity to a program where they would receive ... insurance company. "We were surprised to see ... Michael LaColla , CEO of Troubadour Research, "primarily because ...
(Date:4/26/2016)... LONDON , April 26, 2016 ... EdgeVerve Systems, a product subsidiary of Infosys (NYSE: ... a partnership to integrate the Onegini mobile security ... (Logo: ) The ... enhanced security to access and transact across channels. ...
(Date:4/14/2016)... 2016 BioCatch ™, the ... announced the appointment of Eyal Goldwerger as ... Goldwerger,s leadership appointment comes at a time of ... deployment of its platform at several of the world,s ... discerns unique cognitive and physiological factors, is a winner ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Mass. , June 23, 2016   ... development of novel compounds designed to target cancer ... napabucasin, has been granted Orphan Drug Designation from ... the treatment of gastric cancer, including gastroesophageal junction ... stemness inhibitor designed to inhibit cancer stemness pathways ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... and Mold) microbial test has received AOAC Research Institute approval 061601. , “This ... introduced last year,” stated Bob Salter, Vice President of Regulatory and Industrial Affairs. ...
(Date:6/23/2016)... ... June 23, 2016 , ... Supplyframe, the Industry ... Supplyframe Design Lab . Located in Pasadena, Calif., the Design Lab’s mission ... hardware projects are designed, built and brought to market. , The Design Lab ...
(Date:6/23/2016)... NEWPORT BEACH, Calif. , June 23, 2016 /PRNewswire/ ... offering new biological discoveries to the medical community, has ... and co-founder Matthew Nunez . "We ... provide us with the capital we need to meet ... funding will essentially provide us the runway to complete ...
Breaking Biology Technology: