Blind mice see after cell transplant - Study suggests newborn cells best for transfer.

news@nature.com ^ | 8 November 2006 | Helen Pearson

[neverdem]

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Published online: 8 November 2006; | doi:10.1038/news061106-10

Blind mice see after cell transplant

Study suggests newborn cells best for transfer.

Helen Pearson

A transplanted cell (green) connects up to the host retina (blue). MacLaren et al

Using a technique that may one day help blind people to see, researchers have shown in mice that retinal cells from newborns transplanted into the eyes of blind adults wire up correctly and help them to detect light.

The finding challenges conventional biological thinking, because it shows that cells that have stopped dividing are better for transplantation than the stem cells that normally make new cells.

For decades, researchers have sought a way to replace the light-detecting cells that carpet the back of our eyes — and which break down in diseases such as retinitis pigmentosa and macular degeneration. But they have struggled to find cells that will work normally after being transplanted into the eye.

To find the best cell type, researchers led by Anand Swaroop at University of Michigan, Ann Arbor, and Robin Ali at University College London, UK, extracted cells from the retinas of mice at various times when photoreceptors are normally being generated, as embryos and after they are born. They then injected these cells into adult mouse retinas and counted how many new photoreceptors were generated.

Cells produced in the few days after birth generated the most new photoreceptors after transplantation and connected to the retina correctly, they found. These cells were destined to be photoreceptors but had not fully matured into rods, the cells that detect low light. The results are published in Nature¹.

It's very, very, very exciting.  Robert MacLaren, Moorfields Eye Hospital, London.

Injecting these cells into the eyes of partially blind mice improved the animals' sight, making their pupils react to light. "For us ophthalmologists it's very, very, very exciting," says Robert MacLaren, one of the study's authors at Moorfields Eye Hospital, London. "We can suddenly see in our minds a potential treatment."

From mice to man

It would be difficult to obtain equivalent human cells for transplantation, because they would have to come from fetuses in the first or second trimester of pregnancy. But Maclaren says that it may soon be possible to grow the correct retinal cells from adult stem cells or embryonic stem cells.

In the past there have been many attempts at transplanting tissue into the adult retina. Some researchers have transferred whole sheets of fetal retina into animals — a method that is now showing good results in tests on humans, says Robert Aramant of the company Ocular Transplantation in Louisville, Kentucky.

But these sheets do not join properly to the rest of the retina, says Thomas Reh, who studies retinal development at the University of Washington, Seattle. And transplanted stem cells have not efficiently generated new photoreceptors or restored sight. "This new work is head and shoulders above most of the other studies," Reh says.

MacLaren thinks that his cells are well suited to transplantation, because they are only one step from being adaptable stem cells and can tolerate being moved from one eye to another. Also, they are newly committed to becoming photoreceptors, so that they continue to grow into photoreceptors even after the move.

Researchers will now want to test whether newborn cells, rather than stem cells, are successful in other transplants, Reh says: "We've been doing it all wrong". Grafting new spinal neurons, for example, might help treat spinal-cord injuries.

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References

1. MacLaren R. E. , et al. Nature, 444 . 203 - 207 (2006). | Article |

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[kinoxi]

Usually section 2b, right by the weather.

[neverdem]

You want mouse parts transplanted inside of you enjoy. I'll watch.

Just the emotionalism already expressed on this thread is appalling. I won't write what I would like to write.

While this study used photoreceptor precursor cells extracted from the eyes of newborn mice, MacLaren is confident that adult stem cells could also be genetically manipulated to produce high numbers of precursor cells in the lab.

This is basic clinical science and genetics. When these genes are turned on and off will give answers. Don't be surprised when answers from mice are very similar to humans.

[kinoxi]

Like I said enjoy. I'll watch.

[neverdem]

Like I said enjoy. I'll watch.

Please study a little more than just watch. The left needs hard scientific articles and arguments to rebut their BS. By BS, I don't mean Bachelor of Science, although that degree usually has a greater value than Bachelor of Arts.

[Dr. Scarpetta]

Bump

[RoadTest]

It isn't enough for them to slaughter babies in the womb; now they're ripping cells out of young children's eyes?

Science and human sacrifice aren't so far apart after all, are they? I hate to hear what they'll do next.

[Robert A Cook PE]

Soon, the blind mice will be voting democrat.

Well, actually, now they're voting democrat, after they can see they might change their minds.

[agere_contra]

There was an article yesterday on sucessful treatment of macular degneration with ADULT stem cells by scientists in the UK.

Other cells were also tested (e.g. mice embryo) but it was IIRC the adult stem cells growing in an adult's own eye that showed the most promise.

[Robert A Cook PE]

Abortion (hatred of Christians in particular) more than anything.

Money? important, but not driving force.

It's the result of the driving hatred.

[kinoxi]

I am skeptical of rat studies.

[neverdem]

I am skeptical of rat studies.

IIRC, I just heard that they have 90% of our genes. They test on monkeys or apes before attempting phase I studies on humans.