Diabetes is one of our most common chronic diseases, and one that not only causes great suffering for the patient, it is also very costly to society. Scientists at Karolinska Institutet have now discovered a new mechanism regulating how the pancreatic beta cell releases insulin into the blood when needed. Insulin is the hormone that controls glucose levels. Type II diabetes is caused when the beta cells are no longer able to release sufficient insulin to compensate for the body’s insulin insensitivity.
The newly discovered mechanism involves a molecule called InsP7. InsP7 is a member of a large family of phosphorylated inositols, chemical substances that play an key role in cell function. The researchers have found that InsP7 is an important signal molecule in the regulation of insulin release.
“The discovery gives us hope of finding new diabetes medicine,” says Per-Olof Berggren, professor at the Rolf Luft Centre for Diabetes and Endocrinology Research at Karolinska Institutet, who led the study together with Associate Professor Christopher Barker of the same department.
Professor Berggren noted with interest that the gene regulating the synthesis of InsP7 in the beta cell appears to have become mutated in a Japanese family with a congenital predisposition to type II diabetes. Mice lacking this gene also display many of the defects connected with human diabetes.
“The signal pathway that we have now identified in the beta cell can therefore be of immense strategic importance to our attempts to understand and treat diabetes,” says Professor Berggren.
”Requirement of Inositol Pyrophosphates for Full Exocytotic Capacity in Pancreatic b Cells”
Christopher Illies, Jesper Gromada, Roberta Fiume, Barbara Leibiger, Jia Yu,
Kirstine Juhl, Shao-Nian Yang, Deb K. Barma, John R. Falck, Adolfo Saiardi,
Christopher J. Barker, Per-Olof Berggren
Science, 23 November 2007