Wednesday, August 26, 2009

U. of Wisconsin scientist David Gamm announces success turning skin cells into light sensitive retinal cells

Eye cells that are sensitive to light have been produced from skin in a breakthrough that could eventually lead to treatments for blindness

By Richard Alleyne, Science Correspondent

Scientists genetically “reprogrammed” human skin cells to possess the same properties as those that make up the retina.

The process involved first turning them into pluripotent stem (IPS) cells, which have the potential to develop into virtually every kind of tissue in the body.

By exposing the IPS cells to a specific cocktail of chemicals, the scientists then caused them to grow into partially developed retina cells – the light-sensitive cells at the back of the eye which transmit nerve signals to the brain.

Although the work, published in the Proceedings of the National Academy of Sciences, is at a very early stage, it paves the way for treatments that allow retinas to be repaired with cells grown from a patient’s own skin.

In the more immediate future scientists could use the cultivated cells to study genetically-linked eye disorders, or screen new drugs for retina conditions.

Study leader Dr David Gamm, from the University of Wisconsin, said: “This is an important step forward for us, as it not only confirms that multiple retinal cells can be derived from human IPS cells. but also shows how similar the process is to normal human retinal development.

“That is quite remarkable given that the starting cell is so different from a retinal cell and the whole process takes place in a plastic dish.

“We continue to be amazed at how deep we can probe into these early events and find that they mimic those found in developing retinas.

“Perhaps this is the way to close the gap between what we know about building a retina in mice, frogs and flies with that of humans.”

Tests showed that the IPS cells gave rise to many types of retina cell, including the photoreceptors that turn light impulses into electrical nerve signals.

In previous research, scientists have succeeded in restoring vision to blind mice by repairing their retinas with stem cells.

Future treatments could help patients with conditions such as macular degeneration, the leading cause of blindness among the elderly.

Another disorder involving damage to the retina is retinitis pigmentosa, which causes tunnel vision and blindness.

* Meanwhile, a new kind of "patch” made from stem cells that can mend a broken heart after an attack has been successfully tested by scientists.

Cells lost from the heart do not grow back naturally, leaving the organ in a weakened and vulnerable state.

Researchers in Israel demonstrated the new patch in rats with injured hearts.

Article from The Telegraph


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