New Scientist Breaking News - Human blood cells coaxed to produce insulin

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Human blood cells coaxed to produce insulin

Tantalising experiments that seem to have made human blood cells start

producing insulin have raised the prospect of a new treatment for

diabetes. Although the treatment has only been tried in mice so far, it

might mean people can be cured with implants of their own cells.

But even the researcher whose team carried out the work says he will

remain sceptical until other groups have repeated it. “If it’s true, it

would be very nice, but the data is very preliminary,” cautions Bernat

Soria, chairman of the European Stem Cell Network.

Juvenile-onset diabetes is caused by the immune system destroying the

insulin-producing beta cells in the pancreas. It can now be treated by

transplanting beta cells taken from cadavers, using a technique called

the Edmonton protocol. But many recipients suffer severe side effects

because of the drugs they have to take to prevent their immune systems

rejecting the foreign cells. Also, the supply of beta cells is limited

– only 500 people have been treated so far.

Several teams around the world have now managed to derive

insulin-producing cells from human embryonic stem cells (ESCs). While

this might one day end the shortage of beta cells for transplantation,

it is not a perfect solution.

One problem is that there is no easy way to derive ESCs from individual

patients, so obtaining matching cells might not be possible and

immunosuppressant drugs would likely still be needed. And even if the

beta cells were a perfect match, without drugs they might still be

destroyed by the same autoimmune reaction that killed patients’

original beta cells.

Beta cells

Soria’s team at the Institute of Bioengineering in Alicante, Spain, was

the first to obtain insulin-producing cells from mouse ESCs and is also

working with human ESCs. Recently, together with Fred Fandrich of the

University of Kiel in Germany, the team tried a different approach:

exposing human white blood cells to the same growth factors it had

applied to mouse ESCs. It worked. “We convinced white blood cells to

produce insulin,” Soria says.

When the transformed cells were injected into diabetic mice, their

blood sugar levels returned to normal, Soria told a recent conference

on stem cells in Edinburgh, UK. After a week the effect disappeared,

because the animals’ immune systems destroyed the human cells. The full

results will appear soon in Gastroenterology.

The next step is to find out if insulin-producing cells can be derived

from the blood of people with diabetes, and if they will be stable

after re-implantation. One great advantage of the approach, if it

works, is that white blood cells are very easy to obtain.

It is not yet clear whether the insulin-producing cells have actually

become beta cells or another cell type that has been persuaded to make

insulin, says Burns of King’s College London, who studies beta

cells. This should not matter as long as the cells produce normal

insulin in response to rising blood sugar levels, he says.

“If this is the case, then this would be a significant advance.” It

could even be an advantage if the cells are not true beta cells, as it

means they might escape the autoimmune reaction that causes juvenile

diabetes.

http://www.newscientist.com/article.ns?id=dn7212