Human hair follicles found to be a new source of adult stem cells

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Human hair follicles found to be a new source of adult stem cells

http://www.news-medical.net/?id=18843

Researchers at the University of Pennsylvania School of Medicine have

isolated a new source of adult stem cells that appear to have the

potential to differentiate into several cell types.

If their approach to growing these cells can be scaled up and proves

to be safe and effective in animal and human studies, it could one

day provide the tissue needed by an individual for treating a host of

disorders, including peripheral nerve disease, Parkinson's disease,

and spinal cord injury.

" We are very excited about this new source of adult stem cells that

has the potential for a variety of applications, " says senior author

Xiaowei () Xu, MD, PhD, Assistant Professor of Pathology. " A

number of reports have pointed to the fact that adult stem cells may

be more flexible in what they become than previously thought, so we

decided to look in the hair follicle bulge, a niche for these cells. "

Xu and colleagues report their findings in the latest issue of the

American Journal of Pathology.

Hair follicles are well known to be a source for adult stem cells.

Using human embryonic stem cell culture conditions, the researchers

isolated and grew a new type of multipotent adult stem cell from

scalp tissue obtained from the National Institute of Health's

ative Human Tissue Network.

The mutipotent stem cells grow as masses the investigators call hair

spheres. After growing the " raw " cells from the hair spheres in

different types of growth factors, the investigators were able to

differentiate the stem cells into multiple lineages, including nerve

cells, smooth muscle cells, and melanocytes (skin pigment cells).

The differentiated cells acquired lineage-specific markers and

demonstrated appropriate functions in tissue culture, according to

each cell type. For example, after 14 days, 20% to 40% of the cells

in the melanocyte media took on a weblike shape typical of

melanocytes. The new cells also expressed biomarkers typical of

pigment cells and when placed in an artificial human skin construct,

produced melanin and responded to chemical cues from normal epidermis

skin cells.

After 14 days, about 10% of the stem cells in the neuronal cell line -

- a type of cell not present in skin or hair -- grew dendrites, the

long extensions typical of nerve cells and expressed neuronal

proteins. The neurotransmitter glutamate was also present in the

cells, but the neurotransmitter dopamine was not detected.

Thirdly, about 80% of the stem cells grown in the muscle media

differentiated into smooth muscle cells. These new muscle cells also

contracted when placed in a collagen matrix.

Overall, the researchers showed that human embryonic stem cell media

could be used to isolate and expand a novel population of multipotent

adult stem cells from human hair follicles. " Although we are just at

the start of this research, our findings suggest that human hair

follicles may provide an accessible, individualized source of stem

cells, " says Xu. The researchers are now working on inducing other

cell types from the hair sphere cells and testing the cells in animal

models. Study co-authors are Hong Yu, Suresh M. Kumar, and Geza Acs,

all from Penn; and Dong Fang, Ling Li, Thiennga K. Nguyen, and

Meenhard Herlyn, all from the Wistar Institute, Philadelphia.

http://www.uphs.upenn.edu