STEM CELL TREATMENT FOR DIABETES TRIAL

STEM CELL TREATMENT FOR DIABETES TRIAL

Nevertheless, a clinical trial started last month to test their therapeutic use in patients. But the cells take 6 weeks to become fully functional ОІ cells, and they can't be studied easily outside the body. Several teams have turned stem cells into precursors of ОІ cells, which mature when placed into experimental animals. Either way, 'it's proved to be an extraordinarily complicated undertaking,' says Mark Magnuson of Vanderbilt University in Nashville, who studies pancreatic development. Later they tried with so-called induced pluripotent stem (iPS) cells, made by reprogramming adult cells into an embryolike state. Indeed, one of the first things researchers tried to make from ES cells was pancreatic ОІ cells. ES cells are pluripotent, which means that in theory they can turn into any of the body's cell types-including ОІ cells. When scientists isolated human embryonic stem (ES) cells in 1998, hopes soared. But matching the precise insulin control achieved by the healthy pancreas is almost impossible, so researchers have hoped for decades to find a way to replace the missing cells. People control their diabetes by injecting carefully calibrated doses of insulin. In type 1 diabetes, the body's immune system mistakenly kills the ОІ cells for still-unknown reasons, and the body is left without insulin. Throughout the day, the pancreas regulates the body's blood sugar levels, responding to an increase in glucose after a meal by secreting insulin, which helps cells take up the sugar. The lab-generated cells should be a valuable tool for studying diabetes and, Melton hopes, could eventually be used to treat patients. 'The diabetes research community has been waiting for ages for this type of breakthrough,' says Jorge Ferrer, who studies the genetics of ОІ cells at Imperial College London. And when implanted into mice with a form of diabetes, the cells can cure the disorder.

The cells the researchers produced respond to glucose by producing insulin, just as normal ОІ cells do. This week, he and his colleagues report a potentially significant step toward that goal: a recipe that can turn human stem cells into functional pancreatic ОІ cells-the cells that are destroyed by the body's own immune system in type 1 diabetes patients such as Melton's son and daughter. For most of the past 2 decades, the developmental biologist at the Harvard Stem Cell Institute has focused his research on finding a cure. His son developed the disease as an infant, and his daughter was diagnosed at age 14.

Douglas Melton is as impatient as anyone for a cure for diabetes.

Stem cell treatment for diabetes