|
||
 |
||
About the Incoming Class
Neuroscience
| Stem Cell Breakthrough Enables Progress in ALS Research |
 |
| Chris Henderson |
For decades, researchers trying to understand why motor neurons degenerate in ALS have been stymied by their inability to study living neurons from patients. Adult motor neurons – the neurons responsible for muscle contraction – are not accessible from patients, and in any case cannot survive in the lab in petri dishes. “As a result, we don’t understand why motor neurons die, and we believe that is preventing us from developing effective therapies,” says Chris Henderson, PhD, professor of pathology, neurology and neuroscience, and co-director of Columbia’s Motor Neuron Center.
Dr. Henderson, Hynek Wichterle, PhD, assistant professor in pathology and cell biology, neurology and neuroscience, Wendy Chung, MD, PhD, Herbert Irving Assistant Professor of Pediatrics in Medicine, and Hiroshi Mitsumoto, MD, DSc, the Wesley J. Howe Professor of Neurology, are all part of the team that collaborated to create the motor neurons, developed from induced pluripotent stem (iPS) cells. These cells are derived from adult skin cells but behave like embryonic stem cells.
Though initial tests indicate that the iPS-derived motor neurons are indeed motor neurons, additional tests are required to see if they are identical to the gold standard – motor neurons derived from embryonic stem cells. If the human iPS motor neurons pass such tests, Columbia researchers plan to use the cells in high-throughput drug screening to try to find compounds that stop or slow motor neuron degeneration.
Researchers also will try to confirm last year’s discovery – made by Serge Przedborski, MD, PhD, the Page & William Black Professor of Neurology (in Pathology and Neurology) – that motor neurons may be killed in ALS by toxins released by neighboring cells in the spinal cord called astrocytes. The experiments were conducted with neurons and astrocytes from mice; the lab is now working to create astrocytes from the new iPS cells to repeat these tests in human cells.
Any scientific and therapeutic advances stemming from the new cells will take time, perhaps years. Even further away is the prospect of implanting iPS motor neurons into patients as therapy, since iPS cells contain viruses left over from the reprogramming process and tumors may form if they are injected into people. In addition, the potential of implanted cells to reverse the disease course is still unclear.
“One of the big misconceptions in stem cell research is the thinking that once we have stem cells we can simply put them into a patient’s spinal cord and be done,” Dr. Wichterle says. “In actuality, we have lots of work ahead of us.”
