Epidermal Neural Crest Cells
Epidermal neural crest cells (EPI-NCSC) are remnants of the embryonic neural crest and give rise to hair, skin, sweat glands, peripheral nerves, facial bones and cartilage, pigment, and some endocrine glands. Maya Sieber-Blum, Ph.D., professor of stem cell science at Newcastle University, said that some of these cells survive in hair follicles, where her group discovered them by accident. “When we saw these neural crest cells in the bulge of hair follicles, we first had to prove they were stem cells.”
The cells were molecularly characterized by long serial analysis of gene expression (longSAGE). Data showed that 19 genes are characteristic for both embryonic neural crest stem cells and EPI-NCSC, but are not expressed by epidermal stem cells. These 19 genes were validated at the protein level by immunocytochemistry. “We used that molecular signature to compare it to other published data to find out if our cells are unique—and they are unique among skin resident stem cells.”
One of the challenges in working with human EPI-NCSC is expansion in cell culture. Dr. Blum said her lab has developed a technique to efficiently accomplish this, but was unable to provide details due to IP restrictions.
In another study, Dr. Blum wanted to see if her cells expressed the same four genes that are used for induced pluripotent stem cells. Data shows that Myc, Sox2, Klf4, and Lin28 are expressed at levels similar to mouse embryonic stem cells. However, the pluripotency genes Nanog and Oct4 are expressed at 700- to 800-fold lower compared to embryonic stem cells. “This likely explains the fact that EPI-NCSC did not form tumors in the spinal cord of mice.”
In collaboration with the Brain Research Institute, the cells were tested in mice with spinal cord injuries. Data showed integration into the spinal cord, cell survival in high numbers, vascularization of the scar, bridging of the lesion, and no tumor formation. Potential therapeutic applications include spinal cord injury, repair of neural degeneration, as well as bone transplants.