Myelin sheaths the axons of nerve cells, but the integrity of this sheathing degrades with age. Transplants of neural stem cells can be used to encourage myelin formation, and researchers are exploring this approach as a therapy for conditions involving more profound myelin loss.
There is always a demand in this sort of research for better and cheaper ways to obtain cells that have the desired effect. It is not trivial, for example, to isolate the right sort of neural stem cell, or establish a protocol for producing these cells from embryonic or induced pluripotent stem cells. A great deal of stem cell research these days involves the discovery of chemical signals, growth environments, and other necessary items to guide the growth of specific cell types.
Here is an example for myelin-forming cells, which will no doubt contribute to the next round of research and development of cell therapies aimed at regrowth of myelin:
Researchers have unlocked the complex cellular mechanics that instruct specific brain cells to continue to divide. This discovery overcomes a significant technical hurdle to potential human stem cell therapies; ensuring that an abundant supply of cells is available to study and ultimately treat people with diseases.
"One of the major factors that will determine the viability of stem cell therapies is access to a safe and reliable supply of cells. This study demonstrates that - in the case of certain populations of brain cells - we now understand the cell biology and the mechanisms necessary to control cell division and generate an almost endless supply of cells."
The study focuses on cells called glial progenitor cells (GPCs) that are found in the white matter of the human brain. These stem cells give rise to two cells found in the central nervous system: oligodendrocytes, which produce myelin, the fatty tissue that insulates the connections between cells; and astrocytes, cells that are critical to the health and signaling function of oligodendrocytes as well as neurons.
One of the barriers to moving forward with human treatments for myelin disease has been the difficulty of creating a plentiful supply of necessary cells, in this case GPCs. Scientists have been successful at getting these cells to divide and multiply in the lab, but only for limited periods of time, resulting in the generation of limited numbers of usable cells. ... Overcoming this problem required that [researchers] master the precise chemical symphony that occurs within stem cells, and which instructs them when to divide and multiply, and when to stop this process and become oligodendrocytes and astrocytes.