Stroke, Alzheimer’s, Parkinson’s, ALS—these neurological conditions strip people of their abilities to think, move or both. One of the goals driving regenerative medicine research is to use stem cells to create neural cells to treat these and other neurodegenerative conditions. Two papers recently published in Proceedings of the National Academy of Sciences USA (PNAS) bring us measurably closer to this goal.In the first paper, Dr. Stuart Lipton, Professor and Director of the Del E. Webb Center for Neuroscience, Aging, and Stem Cell Research, collaborated with lead authors Dr. Sheng Ding of the Gladstone Institutes and Dr. Kang Zhang of the UC San Diego School of Medicine to create large quantities of self-renewing, neural stem cells from human embryonic stem cells. These cells can become many types of brain cells and showed no increased risk of forming tumors, a problem that has plagued other efforts.
This is a big deal. Stem cells have the enticing potential to heal injuries and treat disease, but it has been difficult to produce enough stable cells for clinical use. The ability to create large quantities of neural stem cells brings us a step closer to treatments.
Even better, these scientists have found more than one way of producing neural cells. For several years, researchers have been reprogramming adult cells to become less mature induced pluripotent stem (iPS) cells. From there, iPS cells, like their embryonic cousins, can be differentiated into virtually any type of cell. But this is a long process, requiring multiple steps. What if we could simply convert an adult cell, a skin cell for example, into the target cell, eliminating the need to regress it all the way back to the pluripotent stage?
In the other PNAS paper, in which Dr. Lipton again collaborates with lead author Dr. Ding, as well as Dr. Zhang, the team converted skin cells directly into neural stem cells, a much more efficient process than creating intermediary iPS cells. Once produced, the neural stem cells can give rise to many types of neurons, as well as glial cells, which support neuronal cells.
“These new findings highlight the fact that the stem cell field is quickly making progress in devising methods to generate increased numbers of nerve cells while avoiding the potential of accidentally creating tumors,” said Dr. Lipton. “While more work remains to be done, these kinds of advances will lead to new regenerative therapies for humans in the not-too-distant future.”