Genetically Engineered Mice Regenerate Beta Cells
FRIDAY June 6, 2008 -- Genetically engineered mice in which pancreatic beta cells can regenerate after being induced to die may provide information that leads to improved treatments for type 1 diabetes, researchers say.
Type 1 diabetes occurs when the immune system destroys pancreatic beta cells, which make and release insulin, the hormone that converts blood sugar to energy for cells in the body.
In this study, a team at the University of Texas Southwestern Medical Center at Dallas genetically manipulated mature, insulin-positive pancreatic beta cells in the mice (called PANIC-ATTAC mice) so that the beta cells would die when they came in contact with a drug. The researchers stopped administering the drug and allowed the mice to recover. Within two months, the animals' beta cells had recovered, and their blood glucose levels returned to normal.
It's not clear what enabled the beta cells in the mice to recover, but learning more about this mechanism may prove a major advance in type 1 diabetes research. The researchers are now working to develop a method to isolate the cell population that gives rise to the new beta cells, the study authors said.
The study is to be published in an upcoming issue of the journal Diabetes.
"The ability to induce cell death is not novel. The fact that the beta cells regenerate after we kill them is really the new aspect of this (mouse) model. It enables us to see what kind of event or pharmacological intervention might stimulate or enhance regeneration," senior author Dr. Philipp Scherer, professor of internal medicine, and director of the Touchstone Center for Diabetes Research at UT Southwestern, said in a prepared statement.
"The model allows us to get a transcriptional signature, a fingerprint, of how beta cells fend off the pharmaceutical stimulus we provide to prompt cell death. In other words, it provides a way to identify the most critical factors that protect against beta cell death and to potentially find ways to increase these factors in people with type 1 diabetes," Scherer said.
About one million people in the United States have type 1 diabetes, for which there is no cure or prevention. Type 1 diabetes accounts for between 5 percent and 10 percent of all diagnosed diabetes cases in the United States.
Posted: June 2008