If medical science is going to improve upon the natural healing process or restore failing healing capabilities for the aged, then it certainly can't hurt to know - in great detail - how healing actually works. There's still work to do and much to decipher down at the biochemical, genetic and cellular level, as a recent release makes clear:
Clinicians have known for some time that when the skin is abraded new cells come from the hair follicle. What remained a mystery was the exact nature of the origins of the new cells-specifically, what percentage stems from the deep follicle and what percentage from the epidermis near the wound.
Cotsarelis' team found that adult stem cells from the lowest portion of the hair follicle, or "bulge," quickly ascend the follicle in response to wounding and ultimately comprise about 30 percent of the new cells in a wound when it first starts to heal. In addition, the stem cells respond rapidly to surface wounding-within two days-by generating short-lived "transient-amplifying" cells that respond to acute wound-healing needs.
Using a genetically engineered mouse designed in their lab, the researchers were able to visually follow the fate of the stem cells as they migrated from deep within the skin to the surface wound site. The mouse stem cells express a reporter gene that encodes an enzyme, which can be detected with a special blue-color reaction. "We could see blue lines coming from the follicles going toward the center of the wound," says Cotsarelis. "They formed a striking radial pattern like the spokes of a wheel."
It's encouraging to see just how sophisticated modern biotechnology has already become - an experiment of this sort would have been an expensive pipe dream even 10 years ago, based on knowledge not yet obtained, and tools not yet built or standardized.