Stem Cells Curing Burn-Induced Blindness

mcgrew writes "The AP (via Yahoo) is reporting that Italian researchers can now cure blindness caused by chemical burns using the patient's own stem cells. 'The treatment worked completely in 82 of 107 eyes and partially in 14 others, with benefits lasting up to a decade so far. One man whose eyes were severely damaged more than 60 years ago now has near-normal vision.' Previously, this kind of injury needed either a corneal transplant or stem cells from someone else, both of which are plagued by problems with tissue rejection. Unfortunately, this only works for damaged corneas — so far."

It doesn't always work...

[Garble Snarky]

I believe it is well documented that some humans lose almost all ability to process vision information, if they go long enough without it. Surely this depends on the age at which vision is lost, and the duration of the blindness, but the problem of restoring vision processing, for those who have lost it, is significantly harder to solve.

Re:Stem cell extraction

[stoanhart]

RTFA?

The took them from the rim of the cornea of the unaffected eye, or from unaffected portions if both eyes were damaged.

PLEASE....

[DoofusOfDeath]

Please don't let this be another one of those /. discussions where people conflate generic) stem cell therapy with embryonic stem cell therapy.

Many Christian's oppose the latter, and almost none is against the former.

I'm not even a Christian and I'm *&*#$# tired of the BS that comes from confusing the two positions. Seeing people attack straw men is annoying after the millionth time.

Re:Why arent we funding this??

[Attila Dimedici]

Um, this research was eligible for federal funding under President Bush and I assume it is still eligible for federal funding under Obama. The thing you seem to not have noticed is that this procedure works with adult stem cells, not embryonic stem cells.

Two questions

[Something Witty Here]

Is anyone working on treatments (stem cells, carbon nanotubes,
magic fairy dust, whatever...) for repairing a wrinkled retina?
(It detached, and the fine surgeon didn't get it reattached smoothly,
so that eye is like trying to look through textured privacy glass.)

For the optical wizards out there, what would it take to make
eyeglasses that can correct extreme myopia without changing
the magnification? Would a multiple element lens be able to
do this?

For those of you with extreme myopia, you are at higher risk for
retinal detachment. Talk with your eye doctor about getting
your retina "spot welded" with a laser to prevent this.
You do NOT want your retina to detach!!!

Re:Isn't this what stem cells are there for?

[interkin3tic]

Isn't the bloodstream supposed to distribute stem cells and do repairs like this itself?

No. Stem cells in an adult appear to all be fate restricted to some degree. Embryonic stem cells are often called "pluripotent" meaning they can turn into any type of cell you need. Pluripotent stem cells disappear long before you're born, early on they start to specialize into three broad types of cells, and they get more and more specialized from then on, most appear to eventually get to the point where they'll make just one or two types of cells and that's it. Adult stem cell populations seem to be fate restricted as well. Stem cells in the later embryo and after birth are usually found in discrete niches tightly controlled, not just circulating. Some adult tissues appear to lack stem cells entirely too, I guess the cornea is one of those tissues.

One of the best characterized stem cell systems is in the intestines, you need to refresh your intestines fairly rapidly, its a tough environment for the cells making up your gut and they just don't last very long, getting sloughed every few days if I remember correctly. Those cells spring up from transient amplifying cells which divide very fast to make large numbers of intestine cells, but the transient amplifying cells come from stem cells located somewhere in the wall of the intestine. Last I heard, there was some controversy over which cells of the intestinal crypt were the actual stem cells, but they do appear to be in the walls of the intestine itself, not the bloodstream.

Furthermore, it appears that the intestinal stem cells only produce the lining of the intestine, they don't make the cornea, blood, nerves, bones, skin, etc. Maybe you could find a way to coax them into doing that, but as far as I know, that hasn't been shown yet.

Bottom line though, the stem cells that make up the intestine are in the intestine and make up only intestine. It appears most adult stem cells are similar: they make one type of cell from specific locations. Corneas do not appear to have a natural stem cell reservoir, so if you damage them you appear to be SOL as far as nature goes (I guess? Not really too familiar with the eye). In the present study, it looks like the researchers took stem cells from right around the cornea, not the bloodstream. Maybe cells from around the cornea naturally have the ability to differentiate into cornea type cells, I'd have to do some background reading.

But in general, no, there are not pluripotent stem cells floating around in your bloodstream. In cases where adult mice have had pluripotent stem cells injected into their bloodstream, they develop horrible tumors at those sites which are a complex mix of several different types of cells, a teratoma. I think the interpretation there is that stem cells generally need to be under tight control, which can't happen in the blood stream, or else you'll get them doing things you don't want them to do.