Hope for significant new diabetes treatment in Stanford discovery

September 20, 2006

STANFORD, Calif. - Certain immune-suppressing drugs, such as those taken by patients who have had organ transplants, greatly increase the risk of developing diabetes. These drugs are known to put a stranglehold on a protein called calcineurin.

So it's not exactly a surprise that Seung Kim, MD, PhD, assistant professor of developmental biology at the Stanford University School of Medicine, chose to study why calcineurin inhibition leads to the disease. What is surprising is just how central calcineurin turns out to be in the health and happiness of the insulin-producing pancreatic beta cells. His findings, to be published in the Sept. 21 issue of Nature, could shake up diabetes research, lead to new classes of diabetes drugs and aid in efforts to develop stem cell treatments for diabetes.

"This work has the potential to be big," said Scott Campbell, PhD, vice president of research for the American Diabetes Association. He said that drugs based on this research could potentially expand the numbers of the few beta cells that remain in diabetics and make those cells perform better. "That would have a major impact on the lives of people with diabetes."

In diabetes, the beta cells produce too little insulin or none at all, which prevents cells of the body from being able to take in sugar after a meal. Sugar accumulates in the blood, damaging the blood vessels, kidneys and eyes. Diabetics are also prone to nerve damage. In the United States, 20.8 million people, or 7 percent of the population, have diabetes.

Knowing the potential link between calcineurin-inhibiting drugs and diabetes, Kim and MD/PhD graduate student Jeremy Heit collaborated with Gerald Crabtree, MD, professor of pathology, in a series of experiments to clarify the connection. They worked with mice that had been bred to produce calcineurin in the pancreas only until they were born. After birth, the pancreas in each mouse stopped producing the protein. By 12 weeks of age, the mice, which had been born with a normal number of beta cells, were severely diabetic.

Squelching calcineurin prevented the beta cells from increasing their numbers as the mice grew - more body mass requires more beta cells to keep blood sugar in check. It also reduced the amount of insulin made by the existing beta cells. What's more, calcineurin was found to regulate 10 genes that already had been associated with diabetes.

"This work has led us and others to think in entirely new ways about diabetes," Heit said. Until now people had identified individual genes or processes that were involved in diabetes. The new findings show that these lines of research are connected through a common regulator in calcineurin.

Heit and Kim used further genetic trickery to bypass calcineurin by artificially activating its protein sidekick, called NFAT. Beta cells lacking calcineurin but with active NFAT behaved normally, multiplying as the mice aged and producing normal amounts of insulin.

The implications of these findings are many: Kim, whose work in diabetes includes the development of islet cells, identifying new drug targets and potential stem cell treatments, said the calcineurin findings have wide-ranging implications. "The finding that the calcineurin pathway regulates other pathways in the beta cell makes it highly relevant to many areas of diabetes research," he said.

Campbell said the next step is to verify that the findings in mice also hold true in humans. "This is a step in the right direction and a major leap forward, but now we need to take it into to humans," he said.
-end-
Other Stanford researchers who participated in this work include postdoctoral fellow Asa Apelqvist. PhD; graduate students Monte Winslow and Joel Neilson, and research assistant Xueying Gu.

Heit is the recipient of an American Diabetes Association Medical Scholars Grant. Winslow is supported by a Stanford graduate fellowship and a Howard Hughes Medical Institute Predoctoral Fellowship. The study was supported by awards to Crabtree from HHMI and the NIH, and to Kim from the NIH, the Biomedical Scholars Program of the Pew Charitable Trusts and the Stephen and Caroline Kaufer Fund for Neuroendocrine Tumor Research.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital at Stanford. For more information, please visit the Web site of the medical center's Office of Communication & Public Affairs at http://mednews.stanford.edu.

Stanford University Medical Center

Related Diabetes Articles from Brightsurf:

New diabetes medication reduced heart event risk in those with diabetes and kidney disease
Sotagliflozin - a type of medication known as an SGLT2 inhibitor primarily prescribed for Type 2 diabetes - reduces the risk of adverse cardiovascular events for patients with diabetes and kidney disease.

Diabetes drug boosts survival in patients with type 2 diabetes and COVID-19 pneumonia
Sitagliptin, a drug to lower blood sugar in type 2 diabetes, also improves survival in diabetic patients hospitalized with COVID-19, suggests a multicenter observational study in Italy.

Making sense of diabetes
Throughout her 38-year nursing career, Laurel Despins has progressed from a bedside nurse to a clinical nurse specialist and has worked in medical, surgical and cardiac intensive care units.

Helping teens with type 1 diabetes improve diabetes control with MyDiaText
Adolescence is a difficult period of development, made more complex for those with Type 1 diabetes mellitus (T1DM).

Diabetes-in-a-dish model uncovers new insights into the cause of type 2 diabetes
Researchers have developed a novel 'disease-in-a-dish' model to study the basic molecular factors that lead to the development of type 2 diabetes, uncovering the potential existence of major signaling defects both inside and outside of the classical insulin signaling cascade, and providing new perspectives on the mechanisms behind insulin resistance in type 2 diabetes and possibly opportunities for the development of novel therapeutics for the disease.

Tele-diabetes to manage new-onset diabetes during COVID-19 pandemic
Two new case studies highlight the use of tele-diabetes to manage new-onset type 1 diabetes in an adult and an infant during the COVID-19 pandemic.

Genetic profile may predict type 2 diabetes risk among women with gestational diabetes
Women who go on to develop type 2 diabetes after having gestational, or pregnancy-related, diabetes are more likely to have particular genetic profiles, suggests an analysis by researchers at the National Institutes of Health and other institutions.

Maternal gestational diabetes linked to diabetes in children
Children and youth of mothers who had gestational diabetes during pregnancy are at increased risk of diabetes themselves, according to new research published in CMAJ (Canadian Medical Association Journal).

Two diabetes medications don't slow progression of type 2 diabetes in youth
In youth with impaired glucose tolerance or recent-onset type 2 diabetes, neither initial treatment with long-acting insulin followed by the drug metformin, nor metformin alone preserved the body's ability to make insulin, according to results published online June 25 in Diabetes Care.

People with diabetes visit the dentist less frequently despite link between diabetes, oral health
Adults with diabetes are less likely to visit the dentist than people with prediabetes or without diabetes, finds a new study led by researchers at NYU Rory Meyers College of Nursing and East Carolina University's Brody School of Medicine.

Read More: Diabetes News and Diabetes Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.