[biomed] physorg: mouse ESCs => insuling-producing cells, work in mice

[Alejandro Dubrovsky]

(
http://www.physorg.com/news146409227.html
)

Pure insulin-producing cells produced in mouse
General Science / Biology
Singapore researchers have developed an unlimited number of pure
insulin-producing cells from mouse embryonic stem cells (ESCs).

These pure insulin-producing cells, which according to electron
microscopy studies, have the same sub-cellular structures as the
insulin-producing cells naturally found in the pancreas, were highly
effective in treating diabetes in the mouse model.

The transplants of pure insulin-producing cells reduced the blood
glucose levels of diabetic mice with high blood glucose levels.

The experiments also showed that the subsequent removal of the
transplanted cells from the diabetic mice restored the blood glucose to
its original high level.

None of the diabetic mice involved in the transplant experiments
developed teratoma, which are a type of tumour often associated with
ESCs and which could complicate their use in human therapeutic
treatment.

Furthermore, the pure insulin-producing cells managed to retain their
insulin-production and glucose-sensing capacity over time.

The Singapore researchers' achievement provides proof of principle that
this strategy could be applied to human ESCs to obtain similar pure
insulin-producing cells.

These research findings were published in two separate papers in the
July and August 2008 online versions of the journal Stem Cell Research.

Conducting the research were scientists at the Institute of Medical
Biology (IMB), which is under Singapore's Agency for Science, Technology
and Research (A*STAR), and the Yong Loo Lin School of Medicine (YLLSoM )
at the National University of Singapore (NUS).

The team of researchers was co-led by Dr. Lim Sai Kiang, an IMB
principal investigator and a research associate professor at the YLLSoM
Department of Surgery, and Dr. Li Guodong, a research associate
professor at National University Medical Institutes, YLLSoM, NUS.

Commenting about these findings, Dr. Gordon Weir, Director of the
Clinical Islet Transplantation Program at Harvard Medical School, who
also holds appointments at the Harvard Stem Cell Institute and Joslin
Diabetes Centre, said, "The amount of careful work done by this group of
researchers is impressive. We need something to put into diabetic
patients to treat their condition, and these findings tell us
interesting things about the development of beta cells."

The strategic approach by the group offers avenues for further research
in the treatment for diabetes. Said Dr. Lim, "Our ability to isolate and
then multiply insulin-producing cells from differentiating ESCs provides
an unlimited supply of pure insulin-producing cells to study in
unprecedented detail many aspects of these cells."

Added Dr Li, "Besides providing a tool to facilitate basic research in
test tubes and animals, these insulin-producing cells may be also used
to replace the isolated native pancreatic cells that are hard to obtain
in a large amount, for pharmacological tests".

Source: Agency for Science, Technology and Research (A*STAR), Singapore