Scientists from the University of California have successfully used human pluripotent stem cells to regenerate a spinal cord after injury. This study was conducted on rats so further research is still required. Furthermore the cells source was not made clear. pluripotent stem cells (PSCs) can be used to describe embryonic stem cells or induced pluripotent stem cells (from an adult)
Although the latter is more experimental (1), which is why you will find the former case in most definitions pertaining to pluripotent stem cells. That of course raises ethical concerns for some people – If you can only get PSCs from an embryo does that not incentivize the dehumanization of life’s earlier stages? Is this primarily a religious concern? Such quandaries were a huge hurdle preventing stem cell research for the longest time.
Hopefully we can eventually resolve this by furthering research in to induced pluripotent stem cells. However, one thing is for sure – the following study proves that it is at least possible to regenerate an entire spine with neural stem cells, regardless of the origin. That of course means potentially salvaging the quality of life for tens of thousands who suffer from spinal disorders and even helping the paralyzed to walk again.
In the study researchers from the San Diego School of Medicine carefully grafted a set of neural stem cells prepared from hPSCs on to the injured spine of a rat.
Full of excitatory neurons (charged and ready to fire) these neural stem cells began to expand over a large distance successfully sprouting axons and supplanting nerves on to the targeted tissue.
The end result? Complete regeneration of the rats corticospinal system.
“We established a scalable source of human spinal cord NSCs that includes all spinal cord neuronal progenitor cell types,” said Kumamaru. “In grafts, these cells could be found throughout the spinal cord, dorsal to ventral. They promoted regeneration after spinal cord injury in adult rats, including corticospinal axons, which are extremely important in human voluntary motor function. In rats, they supported functional recovery.”
The good thing about neural stem cells is that you can freeze them for long periods of time. Perhaps in the future we will also be able to clone them without having to use embryonic stem cells anymore.
According to the scientists at UCLA this same batch of NSCs will be cryo-preserved for three to five years in preparation for human clinical trials. They till nee to figure out whether ornot transplantation is safe over longer periods of time in both rodent and primate studies.
Aside from regeneration NSCs can be used in modeling and drug screening for disorders that involve spinal cord dysfunction, including
- amyotrophic lateral sclerosis
- progressive muscular atrophy
- hereditary spastic paraplegia
- spinocerebellar ataxia,
All of which are genetic disorders characterized by progressive loss of coordination in gait, hands and eye movement.