When there is an injury to the spinal cord and neurons are damaged, patients are often paralyzed and there is little hope for recovery as neurons in the spinal cord do not regenerate. There are currently no effective treatments that allow significant recovery of function from spinal cord injuries; but research conducted at the Indiana University School of Medicine suggests it may be possible to reprogram cells to generate functional neurons.
When an injury is sustained to the spinal cord, glial cells respond and form scar tissue. There are three types of glial cells – astrocytes, ependymal, and NG2. The researchers investigated whether these cells could be modified to generate mature, functional neurons.
The researchers’ studies showed that only NG2 glial cells had any neurogenic potential in the spinal cord in their studies on adult mice, but they were not capable of generating mature neurons.
SOX2 is a transcription factor found inside the cells which is critical to neurogenesis. The researchers found that increasing the concentration of the SOX2 transcription factor inside the cells allowed them to achieve glia-to-neuron conversion in adult mice with spinal cord injuries to rebuild neural circuits and promote injury recovery.
The research showed that it is possible to generate neurons to replace those that have been lost due to spinal cord injury, while also reducing the size of glial scars in the lesion area of the damaged tissue.
“Ectopic SOX2-induced neurogenesis proceeds through an expandable ASCL1+ progenitor stage and generates excitatory and inhibitory propriospinal neurons, which make synaptic connections with ascending and descending spinal pathways,” explained the researchers. “These results reveal a latent neurogenic potential of somatic glial cells, which can be leveraged for regenerative medicine.”
You can read more about the study in the paper – In vivo reprogramming of NG2 glia enables adult neurogenesis and functional recovery following spinal cord injury – which was recently published in Cell Stem Cell. DOI: 10.1016/j.stem.2021.02.009