A Stem-Cell Discovery Could Help Diabetics
by ilene - September 2nd, 2009 2:34 pm
A Stem-Cell Discovery Could Help Diabetics
By Alice Park, courtesy of TIME

Researchers are inching ever closer to bringing the latest stem-cell technologies from bench to bedside — and are, in the process, learning more about some diseases that long have remained medical black boxes.
This week, scientists at the Harvard Stem Cell Institute (HSCI) reported the first success in generating new populations of insulin-producing cells using skin cells of Type 1 diabetes patients. The achievement involved the newer embryo-free technique for generating stem cells, and marked the first step toward building a treatment that could one day replace a patient’s faulty insulin-making cells with healthy, functioning ones.
The experiment, published in the Proceedings of the National Academy of Sciences, also provided the first good model — in a petri dish — of how Type 1 diabetes develops, giving scientists a peek at what goes wrong in patients affected by the disease. Such knowledge could lead to not only new stem-cell-based treatments, but also novel drug therapies that might improve the symptoms of the disease.
Douglas Melton, co-director of HSCI, and his team took skin cells from two Type 1 diabetes patients, exposed the cells to a cocktail of three genes that converted them back to an embryonic state — which are referred to as pluripotent stem cells — then instructed the newly reborn cells to grow into beta cells, the cells in the pancreas that secrete insulin. In Type 1 diabetes, these beta cells no longer work to break down the glucose that floods the body after each meal, leading to blood-sugar spikes that can damage the kidneys and heart.
To test whether their lab-made cells could function like normal beta cells, Melton’s group exposed them to glucose in a dish. When sugar levels were high, the cells produced more of a protein that beta cells release when they break down sugar; when glucose levels were low, the protein levels were low as well.
"These cells represent the newest model of diabetes for humans," says Melton. "We have a lot of good models of Type 1 diabetes in the mouse, but everything that we have learned from them has failed in the clinic. Now we have a chance at figuring out how humans get the disease."…