Skip to comments.Human stem cells help blinded rats
Posted on 09/21/2006 8:33:39 AM PDT by xjcsa
WASHINGTON (Reuters) - Human embryonic stem cells can partly restore vision in blinded rats, and may offer a source of transplants for people with certain eye diseases, researchers at a U.S. company reported on Thursday.
The finding, published in the journal Cloning and Stem Cells, might offer a way to use stem cells that now exist in laboratories, the researchers said.
"We have developed a technology that we hope can be used to treat degenerative eye diseases such as macular degeneration," said Dr. Robert Lanza of Advanced Cell Technology in Worcester, Massachusetts, who led the study.
"We have demonstrated that these human embryonic-stem-cell-derived cells can rescue visual function in animals that otherwise would have gone blind," Lanza said in an e-mail.
Stem cells are a kind of template cell for the body, producing the various tissue and cell types. Those taken from days-old embryos are especially malleable, and can produce any cell or tissue found in the body.
Their use and production is controversial, however, with opponents saying it is unethical to use human embryos in this way. They say there are plenty of good experiments to be done using so-called adult stem cells, and scientists are racing to find potential therapies using both kinds of cells.
President George W. Bush restricted federal funding of human embryonic stem cell research to a few lines, or batches, of cells that existed as of August 2001.
Private companies such as Advanced Cell Technology can do as they like, and Lanza's team used some of those batches from 2001 as well as other batches produced using private funds.
They transplanted the cells into rats genetically engineered to have defective eyes. The rats usually go completely blind.
BYPASSING THE IMMUNE SYSTEM
Lanza's team was trying to get the stem cells to morph into retinal pigment epithelium cells, which support the photoreceptors in the eye.
Right now there is no ready source of these cells, and the company team thought this may be a good place to test out embryonic stem cells.
"First, the eye is an immune-privileged site -- which means transplanted cells won't be rejected as aggressively as the rest of the body," Lanza said.
"And second, many of these diseases are quite serious. For instance, macular degeneration alone affects more than 30 million people worldwide and is the leading cause of blindness in patients over 60 in the United States."
At the start of the experiment, the researchers had to get the stem cells to generate the desired tissue.
"In this study, we reliably generated retinal cells ... from all 18 human embryonic stem cell lines that were studied. In fact, we generated 67 different retinal stem cell lines," Lanza said.
Then they transplanted them into the rats. The cells grew normally and did not -- as is a risk with embryonic cells -- form tumors, Lanza said.
Soon the rats were able to follow lights with their eyes. They had about 70 percent of the spatial acuity of a normal, healthy rat, Lanza's team said. When the rats were killed and their eyes examined, they had grown layers of the retinal cells.
"These observations are very exciting as they show that one day it will be possible to treat diseases of human eyes with cells," said Ian Wilmut, editor-in-chief of the magazine and one of the researchers who cloned the first sheep, Dolly.
Lanza's company has said it might be possible to create banks of human embryonic stem cells that would provide close tissue matches for a variety of patients.
"A bank of about 100 human embryonic stem cell lines could match half of the U.S. population," the researchers wrote.
Tell that to my dad, macular degeneration has robbed him of his sight.
And yes, he has volunteered to be and been a guinea pig on an experimental procedure (Not stem cell related)
they can find the traps now I betcha
Sorry if I offended you; I know macular degeneration is terrible, and I hope the experimental procedure works. I am convinced, however, that embryonic stem cell research is no less immoral than Nazi research on prisoners in the 1930s, no matter what the benefits may be.
Sure--I'm prefectly willing to tell him that it's not right to commit murder just to restore his eyesight. My wife's grandmother went blind for the same reason, but I know she wouldn't accept such a procedure.
Since the eye is ".... an immune-privileged site -- which means transplanted cells won't be rejected as aggressively as the rest of the body,", I'd bet human stem cells would work as well and posssibly better.
See post #6
And the bottom line of the argument is that embryonic stem cells are the shadow effort of the pro-abortion lobby groups. That is the only reason to push to hot and heavy for embryonic stem cell research when two other totally uncontroversial MUCH more plentiful sources of the same kinds of stem cells which have been proven to benefit HUMANS, but those are deliberately ignored by the media, whoare lap dog $2 w****s for the pro-abortion lobby. This is the bottom line.
I challenge anyone to post evidence of embryonic stem cells that have shown ANY benefits in humans, because my wife has found several times more material on how adult and umbillical stem cells actually help humans, and since no one opposes their use, there is no other explaination as to why there is still a push to use embryonic stem cells, when the other is so plentiful and uncontroversial and actually shows great benefits. I liken it to natural resources like oil. If there is oil bubbling up on the grounds surface, and just under the surface, and then there is some oil miles under the water, or in harsh terrain that is very hard and expensive to get to, who in their right mind will demand that the hard to obtain oil be drilled on first, ignoring the oil sitting on or just below the surface? That's just foolish. The stem cell debate isn't about stem cells, it's about abortion. The pro-death protesters desperately want embryonic stem cells so they can further try and show that human embryos are just tissue and not any kind of human life. That's the reality of this whole thing.
If there were no embryonic stem cells and it was another hard to obtain kind of tissue that was the third wheel, it would have been dumped years ago and the debate would have never happenen and the other two kinds would have been further along by now. So really, people that could have been helped at this point HAVEN'T been because the pro-abortion activists so demand that embryonic stem cells be the only kind used. THAT is sick. Creating embryos just to kill them, not coming up with cures for anything, and at the same time, delaying the help that people need and could have received for years, becqause of an agenda to protect abortion by dehumanizing the human embryo. The pro-abortion crowd are really sick people.
I bet you meant, "ADULT" stem cells would work .... Right? I think "human" means embryonic.
Right---sometimes the fingers don't type what the mind is thinking of.
"I think "human" means embryonic."
Well, that's certainly the idea that the media is trying to establish. But according the correct language usage, it can mean either adult or embryonic. In fact, this article is more honest than most--it actually contains the word embryonic.
"Yep - using dead babies to help rats see better."
Well, at least it might help rats to open their eyes and see the real threat?.. And stop blaming Bush for everything in this world.
I was wondering when someone would take that angle on this...
I hope they find a solution.
For what it's worth, in spite of the huge political effort behind funding embryonic stem cell research with tax dollars, and the eagerness of the left-wing press to push it at every opportunity, adult stem cells have generally been found far more useful.
If I were going blind, I still wouldn't accept a cure that involved killing another human being. That's the terrible bind these people are trying to put people in, in hopes of making abortion seem more palatable. But I would hope that, if there's anything in this story, adult stem cells might be a better answer.
But we'd probably need to learn that from a different research group, since evidently the funding or ideology of this group requires them to work with fetal stem cells.
I agree totally.
What exactly does this mean?
Why wasn't this "fact" written as, "A bank of 200 human embryonic stem cell lines could match the entire U.S. population"?
Is some important detail being left out?
Some people seem [ahem] "overly eager" to involve human embryos in their experiments.
Great, once again, the embryonic stem cell researchers have replicated work already done on adult stem cells. In this case, we know that there are bone marrow cells that migrate to and repair damaged retinas and are exploring the chemoattractants that enable this migration and repair.The work is early, and like Lanza's, still in animal models, but it's ahead of the embryonic work.
Do a pubmed search
on "retina adult stem cells."
CONCLUSIONS: Damaged RPE secretes cytokines that have been shown to serve as chemoattractants for BM-derived stem cells (BMSCs). Retina-committed stem cells appear to reside in the BM and can be mobilized into the PB by G-CSF and FL. These stem cells may have the potential to serve as an endogenous source for tissue regeneration after RPE damage.
This study demonstrates that proliferation of a quiescent cell population with retinal stem/progenitor cell characteristics can be reactivated in vivo upon GF injections and suggests that, in adult mammals, the CB is a non-permissive environment for cell migration and neurogenesis.
There's much more on the retinal stem cells, just from this year.
Most retinal pigmentation happens postnatally, so the eye is one of the best chances for learning to recruit and activate appropriate stem cells. (We're already investigating transplanting corneas from non-embryonic stem cells.)
Gotta go slow, though.
One of the fantastic experiences I had in med school was to watch a patient's eyes "Snow" as the white blood cells in them - in reaction to a brain tumor - fell like snow when he sat up.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.