Teeth regrowth

[Taka]

Alligator Stem Cell Study Gives Clues to Tooth Regeneration

Alligators may help scientists learn how to stimulate tooth
regeneration in people, according to new research led by the Keck
School of Medicine of USC.

For the first time, a global team of researchers led by USC pathology
Professor Cheng-Ming Chuong, M.D., Ph.D., has uncovered unique
cellular and molecular mechanisms behind tooth renewal in American
alligators. Their study, titled "Specialized stem cell niche enables
repetitive renewal of alligator teeth," appears in Proceedings of the
National Academy of Sciences, the official journal of the United
States National Academy of Sciences.

"Humans naturally only have two sets of teeth -- baby teeth and adult
teeth," said Chuong. "Ultimately, we want to identify stem cells that
can be used as a resource to stimulate tooth renewal in adult humans
who have lost teeth. But, to do that, we must first understand how
they renew in other animals and why they stop in people."

Whereas most vertebrates can replace teeth throughout their lives,
human teeth are naturally replaced only once, despite the lingering
presence of a band of epithelial tissue called the dental lamina,
which is crucial to tooth development. Because alligators have well-
organized teeth with similar form and structure as mammalian teeth and
are capable of lifelong tooth renewal, the authors reasoned that they
might serve as models for mammalian tooth replacement.

"Alligator teeth are implanted in sockets of the dental bone, like
human teeth," said Ping Wu, Ph.D., assistant professor of pathology at
the Keck School of Medicine and first author of the study. "They have
80 teeth, each of which can be replaced up to 50 times over their
lifetime, making them the ideal model for comparison to human teeth."

Using microscopic imaging techniques, the researchers found that each
alligator tooth is a complex unit of three components -- a functional
tooth, a replacement tooth, and the dental lamina -- in different
developmental stages. The tooth units are structured to enable a
smooth transition from dislodgement of the functional, mature tooth to
replacement with the new tooth. Identifying three developmental phases
for each tooth unit, the researchers conclude that the alligator
dental laminae contain what appear to be stem cells from which new
replacement teeth develop.

"Stem cells divide more slowly than other cells," said co-author
Randall B. Widelitz, Ph.D., associate professor of pathology at the
Keck School of Medicine. "The cells in the alligator's dental lamina
behaved like we would expect stem cells to behave. In the future, we
hope to isolate those cells from the dental lamina to see whether we
can use them to regenerate teeth in the lab."

The researchers also intend to learn what molecular networks are
involved in repetitive renewal and hope to apply the principles to
regenerative medicine in the future.

The authors also report novel cellular mechanisms by which the tooth
unit develops in the embryo and molecular signaling that speeds growth
of replacement teeth when functional teeth are lost prematurely. Co-
authors include colleagues from the Louisiana Department of Wildlife
and Fisheries, University of Georgia, National Cheng Kung University,
National Taiwan University, and Xiangya Hospital in China.

SOURCE: http://www.sciencedaily.com/releases/2013/05/130514101457.htm

[John H. Gohde]

On May 15, 11:00 pm, Taka <taka0...@gmail.com> wrote:
> Alligator Stem Cell Study Gives Clues to Tooth Regeneration
>
> Alligators may help scientists learn how to stimulate tooth
> regeneration in people, according to new research led by the Keck
> School of Medicine of USC.

Heaven help us all. :(