For more than 20 years doctors have used cells from blood taken from umbilical cords and the placenta to treat a variety of illnesses. Now the Salk Institute of Biological Studies is using a single protein to convert cord blood (CB) cells into neuron-like cells for the possible treatment of conditions like stroke, brain and spinal cord injury.
The researchers note that cord blood cells offer a number of advantages over other types of stem cells. They are not embryonic stem cells and thus they are not controversial; they are more plastic, or flexible, than adult stem cells from sources like bone marrow; the collection of CB cells is safe and painless, poses no risk to the donor, and they can be stored in blood banks for later use.
The researchers demonstrated that these CB cells, which come from the middle layer of embryonic germ cells, can be switched to become ectodermal cells, outer layer cells from which brain, spinal and nerve cells arise. “This study shows for the first time the direct conversion of a pure population of human cord blood cells into cells of neuronal lineage by the forced expression of a single transcription factor, ” said Juan Carlos Izpisua Belmonte, a professor in Salk’s Gene Expression Laboratory, who led the research team, in the July 20 news release.
The Salk researchers used a retrovirus to introduce Sox2, a transcription factor that acts as a switch in neuronal development, into CB cells. After culturing them in the laboratory, they discovered colonies of cells expressing neuronal markers. They determined that the new cells, called induced neuronal-like cells (iNC), could transmit electrical impulses, signaling that the cells were mature and functional neurons. They transferred the Sox2-infused CB cells to a mouse brain and found that the cells integrated into the existing mouse neuronal network and were capable of transmitting electrical signals like mature functional neurons.
Researchers hope to use these cells for modeling neurological diseases such as autism, schizophrenia, Parkinson’s or Alzheimer’s disease. The study is published in the Proceedings of the National Academy of Sciences.
