I just got done reading a Nature interview of Elaine Fuchs, who does stem cell research at Rockerfeller University in NYC. Specifically she focuses on how skin stem cells act to maintain and repair the skin.
As I read the article, I found myself asking a lot of questions, that seem obvious but that I rarely think about. Questions like: How exactly does my body repair a cut on my skin? How does it know to do it? What does it have in reserve? Why doesn't it use the same mechanism to keep my skin from looking wrinkled and scathed? How do scars form?
A sample passage:
In the skin, there are stem cells that exist within the bulge of the hair follicle and also in the basal layer of the epidermis. We still don't know whether all of the cells within the basal layer can behave as stem cells or whether only a few stem cells exist that are scattered within this layer. It's an open question of where along the lineage to differentiation is the point of no return where a stem cell becomes irreversibly committed to terminally differentiate. In the skin the point of no return has definitely passed in the dead hair cells or in the enucleated squames [squamous cells] that are sloughed off the skin. But can an epidermal cell that has exited the basal layer and begun its journey to the body surface go backwards under certain circumstances and become a stem cell again?
To answer this question, we need to have a firmer grasp of the key features of a stem cell that determine stemness.
What I suddenly realized reading the article is that all these questions of regeneration are very unknown, and the medical potential of finding out is huge, and beyond that, it would be hugely satisfying as a human to really understand how the mechanics of my body works. I would love to make a working molecular model of a human one day. (In computer simulation of course) ;)
As for the potential of stem cells? Well some wikipedians have put together a good image for that: