Re-Growing Nerve Cells
Too late to help Christopher Reeve, alas, but this looks like the beginning of the breakthrough he was looking for:
BOSTON (Reuters) - Human embryonic stem cells can help regenerate damaged nerves in rats, producing compounds that nurture nerve cells and stimulate the growth of new ones, Geron Corp. said on Wednesday.
Geron had earlier reported that human embryonic stem cells had helped replace myelin, a fatty covering on nerves that is vital to function.
Now, the company's researchers said, they had shown the cells produce multiple nerve growth factors, which are proteins that stimulate the survival and regeneration of neurons.
For victims of paralysis, the ability to replace damaged or missing nerve tissue is the Holy Grail of stem cell research. It will take considerably more than what's been done here before we start seeing people abandoning their crutches and wheelchairs, and even more still before stem cell research offers hope to those who suffer in other ways -- e.g., Parkinson's/ Alzheimer's -- but this is an important step, nonetheless.
Meanwhile, we should be on the lookout for the convergence of other positive developments in this sphere, for example:
WASHINGTON (Reuters) - Stem cells taken from bone marrow replenished the radiation-ravaged immune systems and bone marrow of mice and can also make brain and liver cells, scientists reported on Monday.
These so-called adult stem cells can grow almost indefinitely in the lab and have many of the other valued properties of more controversial embryonic stem cells, Dr. Catherine Verfaillie of the University of Minnesota and colleagues reported.
"The cells not only survived when transplanted but they completely repopulated the blood system of the mice," Verfaillie said.
Writing in the Journal of Experimental Medicine, the researchers said the findings suggest adult stem cells can be manipulated to regenerate a range of cells and tissues.
Replacing brain cells might be more in line with helping the degenerative diseases mentioned above. And of course there will be tremendous benefits for many if the ability to regenerate liver and bone marrow cells pans out.
Additionally, stem cell therapies such as these which can be achieved using adult stem cells represent a kind of Holy Grail in their own right, in that they enable research to move forward without the ethical difficulties raised by embryonic stem cell research. And in addition to these ethical considerations, there's a very practical one -- most stem-cell therapies are intended for adults, or at least for people who stopped being embryos a long time ago. It makes sense to believe that, all things being equal, an individual's own undifferentiated cells -- cells with his or her own DNA -- will prove much more useful in treating any condition than would cells from some other body.