from the University
of Pennsylvania School of Medicine have found that stem cells
play a vital role in male pattern baldness.
Cotsarelis, MD, study leader and chair of the Department of Dermatology at the
University of Pennsylvania School of Medicine, along with a team of
researchers, have discovered that the amount of stem cells on the scalp may
determine male pattern baldness.
came to this conclusion after comparing samples from men who were going through
hair transplants. When looking at samples from both bald parts of the scalp and
non-bald parts of the scalp, both had the same number of stem cells.
asked: 'Are stem cells depleted in bald scalp?'" said Cotsarelis. "We
were surprised to find the number of stem cells was the
same in the bald part of the scalp compared with other places, but did find a
difference in the abundance of a specific type of cell, thought to be a
progenitor cell. This implies that there is a problem in the activation of stem
cells converting to progenitor cells in bald scalp."
and his team of researchers studied their theory a little closer, and found
that hair follicles shrink rather than disappear in male pattern baldness. So
hair is available in bald spots of the scalp, but it's microscopic compared to
other non-balding parts due to the stem cells' problem with activation.
found similar results in 2007 while studying hair follicles in adult mice. He
discovered that “re-awakening” dormant genes in developing embryos could
regenerate hair follicles. They used wound healing in these models to
manipulate certain traits, and by stimulating these once-active genes; stem
cells formed new hair follicles.
are unsure as to why stem cells refuse to convert into the progenitor cells to
maintain a certain amount of hair follicles, but they remain hopeful due to the
fact that both areas on the scalp have the same number of stem cells. That way,
they can find ways to stimulate stem cell conversion and re-grow the hair in
addition to this study, Cotsarelis and his team would like to study female
pattern baldness as well for comparison purposes. This could lead to a larger
understanding of why the hair shrinks in humans, and could lead to the
development of cell-based treatments for
male and possibly female pattern baldness.