WESTPORT, CT (Reuters Health) Dec 08 - For the first time, human neural stem cells have been identified, isolated, and grown in cell culture, according to a press release from NeuralStem Biopharmaceuticals, Ltd., the company that developed and patented the process.
Using this technique, the researchers have shown conclusively that region-specific stem cells rather than a single multipotential cell exist in the nervous system. These findings are published in the most recent issue of NeuroScience News.
Dr. Karl Johe, co-founder and chief scientific officer of the College Park, Maryland-company, told Reuters Health that developmental neurobiologists have always known that during development "there is a definite organization in the epithelium where the functional organization is determined by the physical location and timing of the birth of the cells. In terms of being able to actually capture those cells in culture, this is the first."
"Basically when we isolate the stem cells from different areas of the fetal brain, cortex or midbrain or spinal cord, we assess what the stem cells can do by looking at the differences in phenotypes that come out in culture," he explains. "The key technical step," Dr. Johe emphasized, "is that we allow the cells to differentiate on their own; we are not putting some cocktails in and inducing them to go in a certain direction."
In a study reported by Reuters Health on November 30, Dr. Timothy R. Brazelton, from Stanford University, in California, and colleagues found that bone marrow stem cells could migrate to the central nervous system and express neuronal proteins.
In reference to this study and others, Dr. Johe commented that "the whole notion of taking different cells and turning them into brain cells is conceding to the idea that brain cells cannot be grown. But that's wrong, we've shown that they can be grown. They can be grown and they can develop into physiologically functioning neurons."
"We are in the process of developing the cells for animal experimentation, but we have not gone into people yet. In animals, our main focus has been Parkinson's disease, but we are slowly developing a couple of other models as well, multiple sclerosis for instance and spinal cord injury," he stated.
"Other investigators have implanted fetal nerve cells into adult patients with neurologic diseases, but they have not isolated and grown neural stem cells in culture," Dr. Johe explained. A major factor limiting transplants is the availability of fetal tissue, he noted.
"For something like
Parkinson's, it has been estimated that somewhere between 6 to 10 fetuses
are required to collect enough material to put into one patient. The scale
of the problem is huge. We actually solved this by being able to grow the
stem cells to the area that is needed," Dr. Johe concluded.
2000 Reuters Ltd