Stem Cell Therapy for ALS

While stem cells from embryos take the media spotlight, progress is quietly and rapidly taking place with stem cells from adults as worthwhile therapeutic options in amyotrophic lateral sclerosis (ALS). Johns Hopkins researcher Lee Martin, Ph.D., who is funded by The ALS Association (ALSA), shows there is hope for this treatment strategy, as adult stem cells appear to prolong life in mice modeling ALS.

Martin’s team has taken stem cells from the olfactory bulb of adult mice, and placed these into SOD1 mice carrying the mutation that is associated with an inherited ALS. The treatment has extended life and delayed progress of motor symptoms. But bringing this strategy to the bedside will require a lot of wok over many years to make this hope a reality.

Stem cells can live and divide in lab dishes indefinitely, and certain ones have the potential to turn into all cells of the body. Scientists considered this potential limited for adult stem cells, as compared to those from an embryo, but that idea is changing.

Special Needs of Stem Cells

Stem cells need pampering to push them towards developing into different types of cells. Scientists can transfer key genes into stem cells to push them towards becoming a certain type of cell.

Problems that need to be avoided included the potential for implanted cells to form wrong connections, and the possibility of producing tumors or immune rejection. One has to check that the DNA is not altered by growing cells in a dish. These are real issues for stem cell transplants, as they do happen in the animal models.

Initial Success

Martin's aim is to use the animal’s own stem cells as therapy. A relatively easily tapped source is the olfactory bulb, a pair of projecting structures at the front of the brain that govern the sense of smell. Cells obtained from the olfactory bulbs include stem cells that propagate in the lab and can be frozen, stored, and then thawed and used.

Placing these cells into the mice requires painstaking surgery on the spinal cord. Injections successfully delivered the cells, and these cells lived and showed markers of becoming neurons as well as generating the glial cells that surround and aid neurons. The stem cells also sent nerve fibers through the appropriate nerve root out of the spinal cord. Connections appear to form to muscle, as well.

Mice treated by the implants had longer lives and less wasting. The typical 120 day life of the mice with the SOD1 mutation was extended, from 150 to 170 days, after Martin’s team carried out the implants of the stem cells at 100 days.

Will the disease process of ALS turn out to damage the newly minted neurons? That is a critical question. Further research is required to settle all of the issues and to realize the promise of stem cell therapy in ALS.