A newly discovered mouse hormone may open the door to better treatment for
diabetes, researchers suggested Thursday.
The hormone, called betatrophin, triggers the growth of "beta" cells, which
produce insulin in the pancreas, but with diabetes either don't function
properly or become ineffective.
Diabetes afflicts more than 25 million people nationwide, according to the
American Diabetes Association. It is a condition that causes high blood sugar
that can lead to heart disease, kidney failure and blindness.
In the journal Cell, a team led by Harvard's Peng Yi reports that betatrophin
can produce a roughly seventeenfold increase in these cells.
"This is really an amazing discovery. Hormones with this kind of effect aren't
discovered very often, and this opens a whole new pathway to treating diabetes,"
says diabetes expert Jake Kushner of the McNair Medical Institute at Baylor
College of Medicine in Houston, who was not part of the study team. He cautioned
that the hormone's effects, which the study team sees as isolated to beta cells,
need to be thoroughly investigated for safety.
The hormone was discovered almost by accident, as the Harvard team investigated
a research compound that basically recreates what happens in diabetes. The
compound short circuits the release of insulin in response to increasing blood
sugar. When that happened to the mice in the study, their production of the
hormone betatrophin ramped up and spurred the growth of insulin producing cells.
Diabetics often need daily insulin injections to compensate for the condition.
In type 2, or adult-onset diabetes, the most frequent kind, beta cells stop
producing enough insulin, and in juvenile diabetes, or type 1, about 10% of
cases, beta cells have died.
"Of course, we are a long way from a treatment. But if this could be used in
people, what I think it could mean eventually is that instead of taking insulin
injections three times a day, you might take an injection of this hormone once a
week or once a month," says study senior author Doug Melton of the Harvard Stem
Cell Institute, in a commentary provided by the university.
"It will need to be established (that) the molecule drives beta cell replication
in humans," says beta cell expert Peter Butler of the University of
California-Los Angeles. He cautions that "a variety" of compounds have earlier
been identified that drive beta cell growth in young mice but then did not have
the same effect on beta cells in people.