Bypassing Induced Pluripotent Stem Cell Stage, Neurons Derived From Cord Blood Cells May Represent New Therapeutic Options

Cord blood (CB) 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, which may make them easier to convert into specific cell lineages. The collection of CB cells is safe and painless and poses no risk to the donor, and they can be stored in blood banks for later use.

Lead by Juan Carlos Izpisua Belmonte, a professor in Salk's Gene Expression Laboratory, the team demonstrated that CB cells, which come from the mesoderm, the middle layer of embryonic germ cells, can be switched to ectodermal cells, outer layer cells from which brain, spinal and nerve cells arise.

"Unlike previous studies, where multiple transcription factors were necessary to convert skin cells into neurons, our method requires only one transcription factor to convert CB cells into functional neurons," said Fred Gage a professor in Salk Institutes's Laboratory of Genetics.

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. Using a variety of tests, 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. Additionally, they transferred the Sox2-infused CB cells to a mouse brain and found that they integrated into the existing mouse neuronal network and were capable of transmitting electrical signals like mature functional neurons.

Adapted from the Salk Institute announcement.