New hopes for diabetes cure
New research into cell differentiation has raised hopes of finding
a cure for insulin-dependent diabetes mellitis. A study published in the Proceedings of the National Academy of Sciences last
month has shown that in vitro,
duct tissue from the human pancreas can be expanded and then
reverted back into pancreatic
stem cells. By culturing these
cells under the correct conditions, they can be directed
towards differentiating into islet
cells. This is an important step
forward in diabetic research as
duct tissue is available in a much
larger volume than that of islet
cells. The American research
team has shown that this process
of ductal tissue differentiation
can produce a 10-fold to 15-fold
increase in insulin content. The
cells also respond appropriately
to increases in blood glucose
volumes.
An islet of Langerhans (centre) surrounded by pancreatic acini (JOHN BAVOSI/SPL)
Insulin dependent diabetes
affects an estimated half a
million people in the United
Kingdom. It results from an
autoimmune destruction of
insulin producing islet cells in
the pancreas. Although it has
been shown that islet cells taken
from external sources can be
successfully transplanted into
humans and begin to produce
insulin, there are not enough
cells to produce viable tissue for
transplantation on a large scale.
This is why this new finding is
such a breakthrough.
Dr Susan Bonner-Weir, who
led the research team from Harvard Medical School, Boston,
hopes that the technique may be
able to produce large numbers
of insulin producing cells to be
used in B cell replacement therapy. "We're like alchemists
changing lead into gold," she
commented, referring to the
transformation of otherwise discarded tissue into the valuable
insulin producing cells.
Although the islet generation is
currently limited in quantity, the
study raises the possibility that
once the process is optimised,
maintaining an in vitro cell
line could produce significant
amounts of new human islet
tissue. Once enough cells are
being produced, tissue transplantation is the next obvious step.
Sian Knight, Nottingham
The full research paper can be viewed at: http://www.pnas.org/cgi/reprint/97/14/7999.pdf
studentBMJ 2000;08:303-346 September ISSN 0966-6494
