Scientists program blood stem cells to become vision cells

University of Florida researchers were able to program bone marrow stem cells to repair damaged retinas in mice, suggesting a potential treatment for one of the most common causes of vision loss in older people.

The success in repairing a damaged layer of in mice implies that blood taken from can be programmed to restore a variety of cells and tissues, including ones involved in cardiovascular disorders such as atherosclerosis and .

"To our knowledge, this is the first report using targeted gene manipulation to specifically program an adult stem cell to become a new cell type," said Maria B. Grant, M.D., a professor of pharmacology and therapeutics at UF's College of Medicine. "Although we used genes, we also suggest you can do the same thing with drugs — but ultimately you would not give the drugs to the patient, you would give the drugs to their cells. Take the cells out, activate certain chemical pathways, and put the cells back into the patient."

In a paper slated to appear in the September issue of the journal Molecular Therapy, scientists describe how they used a virus carrying a gene that gently pushed cultured from mice toward a fate as retinal cells. Only after the stem cells were reintroduced into the mice did they completely transform into the desired type of vision cells, apparently taking environmental cues from the damaged retinas.

After studying the cell-transformation process, scientists were able to bypass the gene manipulation step entirely and instead use chemical compounds that mirrored environmental conditions in the body, thus pointing the stem cells toward their ultimate identities as vision cells.

"First we were able to show you can overexpress a protein unique to a retinal cell type and trick the stem cell into thinking it is that kind of cell," said Grant, who collaborated with Edward Scott, Ph.D., the director of the Program in Stem Cell Biology and Regenerative Medicine at UF's McKnight Brain Institute. "As we proceeded, we found we could activate the stem cells by mimicking the body's natural signaling channels with chemicals. This implies a whole new field of stem cell research that uses drug manipulation rather than genetic manipulation to send these immature cells along new pathways."

Scientists chose to build retinal pigment epithelial cells, which form the outer barrier of the retina. In addition to being very specialized and easy to identify, RPE cells are faulty in many retinal diseases, including age-related macular degeneration, which affects nearly 2 million people in the United States, and some forms of blindness related to diabetes.

"This work applies to 85 percent of patients who have age-related macular degeneration," Grant said. "There are no therapies for this devastating disease."

The work was supported by the National Eye Institute. Researchers removed blood stem cells from the bone marrow of mice, modified the cells in cultures, and injected them back into the animals' circulatory systems. From there, the stem cells were able to home in on the eye injury and become retinal cells.

At 28 days after receiving the modified stem cells, mice that had previously demonstrated no retinal function were no different than normal mice in electrical measures of their response to light.

Grant and UF have patented some technology involved in the research.

Source: University of Florida (news : web)

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Jul 31, 2009
We have president bush to thank for these advances because he forced scientists to do the harder work of developing non-embryonic stem cells into a viable treatment regimine... I remember researching this issue back in the day and discovered that much to my surprise, Bush wasnt being a knuckle-dragging bible thumper, he was trying to force everyone onto the harder high road of an ultimately much more useful technology than the embryonic route... For his Kennedyesque "We choose the moon" decision he was universally derided and criticized as being a extreme right to life loony... Hopefully blind people will soon reap the fruit of his hard decision... I'd take 8 more years of Bush ANY day over the empty suit with the pretty face and suave demeanor!

Jul 31, 2009
Were you born retarded or did you bump your head somewhere along the way?

We have president bush to thank for these advances because blah blah blah...words words meaningless words....
Bush wasnt being a knuckle-dragging bible thumper, he was trying to force everyone onto the harder high road blah blah more complete nonsense ...
I'd take 8 more years of Bush ANY day over the empty suit with the pretty face and suave demeanor!

Aug 01, 2009
No, i just read and study and don't have a closed mind like you, supermegadope... You think in the socialist utopia being built that you stoners are going to continue to hit your chronic and lay around all day on the xbox???

Aug 02, 2009
It would seem a stretch to say that Bush made those choices for scientific reasons. That's what you're saying. Like he had more foresight than the scientific community. Of course it would have been an adviser. I would think we would have heard of such wording. If you can find credible material containing Bush describing the intent of such decisions in the way you claim, that would be interesting. Until then your comment has no credibility.

Aug 06, 2009
you honestly believe the Hate Bush at All costs "dinosaur planet traditional media outlets would have credited bush with taking a high road on something as important as this??? I suppose you believe Obama needs no advisors at all right? He knows all, sees all and is all powerful right? sounds like a cult of personality type leader worship syndrome... try moving to North Korea if you want to be surrounded by cult members or just join scientology...

Sep 02, 2009
What exactly has Bush to do with the research? It would work with ANY kind of stem cells. The embryonic are just easier to get, I don't think anyone considered them the best option. What's wrong with you people?!
Besides, messing with your bone marrow usually is EXTREMELY painful. Just imagine how much pain would have been induced into people if all the experiments with stem cells were coming from bone marrow. Get real people. Science is rarely a straight road, but don't get too carried away...

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