Pregnant Mothers Pass Stem Cells To Their Diabetic Babies To Help Them Make Insulin

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Main Category: Diabetes
Also Included In: Stem Cell Research;  Pediatrics / Children's Health;  Pregnancy / Obstetrics
Article Date: 23 Jan 2007 - 6:00 PDT


A team of UK and US scientists have discovered that stem cells can pass from the mother to her diabetic foetus during pregnancy and help it to produce insulin.

The research was conducted by a team of scientists from the University of Bristol in the UK and Seattle's Fred Hutchinson Cancer Research Center in the US.

The results are published in the current early online edition of the Proceedings of the National Academy of Sciences.

The scientists discovered that maternal stem cells can pass through the placenta into the developing child and differentiate into "beta-cells" in the foetus's pancreas to produce insulin.

The scientists also discovered 94 children and young adults with type 1 diabetes had significantly higher levels of maternal DNA in their blood compared to 54 brothers and sisters and 24 unrelated volunteers who did not have the disease. They reckon this could be because the mother's DNA comes from cells that traverse the placenta to repair damage in the baby's pancreatic tissue.

Beta-cells are specialist cells in the Islets of Langerhans part of the pancreas and their role is to produce insulin and release it into the bloodstream. Children with type 1 diabetes do not produce enough insulin, a hormone that controls the level of sugar, or glucose, in the blood.

The beta-cells with maternal DNA continue to help the baby's pancreas produce insulin even after birth.

This type of "small scale foreign DNA occupation", where a small part of the body is occupied by cells with DNA that is not representative of the "host", is known as microchimerism. It is not clear whether the presence of the maternal DNA in the child has other, perhaps more harmful, side-effects.

The hope is that this discovery will lead to new treatments for type 1 diabetes and other similar genetic diseases.

Earlier studies have shown evidence of maternal stem cells going into the foetus's blood stream, and that they can still be harmlessly alive in the child many years after birth.

The thing that makes this discovery exciting, is that unlike other "donor" situations, the maternal cells did not appear to be attacking the child's pancreatic tissue, nor to be causing an immune response in the child's body.

This could lead to treatments where a mother's stem cells are used to treat genetic disorders in children, helping to overcome problems with donor mismatching which often happens when stem cells from a non-genetically related donor are harvested. Or there could be other examples of microchimerism that could be exploited for treatment development, said the research team.

Before this study the scientists thought that perhaps the presence of maternal DNA beta-cells in the child's pancreas was preventing the child from developing insulin, but they now believe the obverse is the case. The maternal DNA is actively helping the faulty tissue to repair itself. There is a cooperative thing going on with some child DNA and some maternal DNA to make sure the insulin is being produced.

The scientists also think that the presence of maternal DNA in the child from early embryo stage helps it to develop a tolerance toward this "foreign" DNA. This is what leads them to be hopeful that treatments involving this more "natural" transfer of DNA may present with lower risk of rejection and other donor problems.

In the UK there are about 350,000 people with type 1 diabetes. In the US the figure is close to 3 million.

Diabetes is the leading cause of adult blindness, kidney failure, non-traumatic amputations, nerve damage, stroke and heart attacks in the US.

The Juvenile Diabetes Research Foundation International.

Proceedings of the National Academy of Sciences.

Written by: Catharine Paddock
Writer: Medical News Today
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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