Page URL: https://www.bionews.org.uk/page_89779

Gene therapy cures blind mice

14 August 2005
By BioNews
Appeared in BioNews 321

US scientists have used gene therapy to successfully treat mice with a rare genetic disorder that causes blindness, called retinoschisis. The researchers, based at the University of Florida Genetics Institute, say their method could eventually be used to treat a range of eye diseases in humans.

Retinoschisis causes the retina to split in the middle, leading to gradual sight loss in affected children. There is currently no cure for the disorder, which is usually first detected in boys between five and ten years of age. In healthy eyes, the cells of the retina usually make a protein called retinoschisin, which acts like glue to stick the layers of the retina together. But in children with retinoschisis, this protein is missing, so the layers separate and tiny cysts form, causing blindness.

In the latest study, the scientists used mice with symptoms of retinoschisis equivalent to those of a ten-year-old boy affected by the disease. They injected a healthy copy of the human RS1 gene- which makes the retinoschisin protein - into the right eyes of the mice. Six months later, the team used a laser opthalmoscope to look at the inside of the animals' eyes, and found that while cysts had appeared in the untreated eyes, the treated eyes appeared healthy. The light-detecting rod and cone cells were unaffected, and the layers of the retina were intact.

The researchers, who published their findings in the journal Molecular Therapy, say that the protein made by the therapeutic gene could move within the retina to its target sites, and that the beneficial changes appeared to be long-lasting. They say that it may now take two to five years to try out the treatment in human patients, because of the need for safety studies. The team also say the work has promising implications for other genetic eye diseases that affect the eye's ability to process light, such as retinitis pigmentosa.

Meanwhile, US researcher Katherine High predicts that a successful gene therapy treatment for the blood clotting disorder haemophilia could be available in five years time. 'It has taken approximately 5-8 years to move from a cure for haemophilia in mice to a cure in dogs', she said, adding that the studies carried out on dogs had identified problems that had to be solved before trying the approach in humans. Professor High presented the latest findings last week at a meeting held in Sydney, Australia.

SOURCES & REFERENCES
Gene therapy prevents blindness in mice
Yahoo Daily News |  10 August 2005
Gene therapy to treat haemophilia
EurekaAlert |  9 August 2005
Scientists use gene transfer to prevent retinoschisis
News-Medical.net |  2 August 2005
RELATED ARTICLES FROM THE BIONEWS ARCHIVE
27 June 2011 - by Dr Lux Fatimathas 
Humans may retain a diminished ability to see the Earth's magnetic field, claims a new American study. Experiments were carried out to investigate the function of light-sensitive proteins called cryptochromes, in the eyes of fruit flies and Monarch butterflies...
27 June 2011 - by Dr Nadeem Shaikh 
A group of US scientists has successfully used a virus to deliver genes into monkey retinas that could potentially restore damaged photoreceptor cells. The findings could lead to gene therapies being developed to treat blindness and other eye conditions in humans...
28 March 2011 - by Dr Sophie Pryor 
US scientists have taken an important step towards using stem cells to treat age-related macular degeneration (AMD), the leading cause of blindness in the UK. The study demonstrates, for the first time, the ability to direct human iPS (induced pluripotent stem) cells to become...
20 September 2004 - by BioNews 
The first clinical trial based on a promising new technology called RNA interference (RNAi) is set to begin in the US, to treat a progressive eye disorder. The researchers hope to test the safety of the technique for treating a disease called wet age-related macular degeneration (AMD). This condition, which...
18 February 2002 - by BioNews 
Doctors have successfully used gene therapy in the treatment for a type of haemophilia, a condition caused by a defect in one of the genes which controls blood clotting. Sufferers bruise easily, are prone to nosebleeds, and have a risk of internal bleeding. A virus that had been genetically altered...
30 April 2001 - by BioNews 
Gene therapy has enabled dogs born blind because of an inherited disorder to have some of their sight restored. This is the first time that gene therapy of this type has proved to be successful in a large animal. The achievement might mean that the technique could be adapted to...
HAVE YOUR SAY
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions


Syndicate this story - click here to enquire about using this story.