Sam Stephens, PhD, assistant professor in Endocrinology and Metabolism, recently earned a $1.2M grant from the Department of Defense’s (DOD) Congressionally Directed Medical Research Program (CDMRP). Additionally, Dr. Stephens received a three-year, $345,000 Innovative Basic Science Award from the American Diabetes Association (ADA). The projects for each of these grants focus on understanding insulin packaging in islet beta-cells in healthy and diabetic states and how this impacts insulin release. The DOD grant is scheduled to begin in April and the ADA in July.
Islet beta-cells are small clusters of pancreatic cells, and these beta-cells use the hormone insulin to regulate blood sugar. During the course of type 2 diabetes, the islet beta-cells ramp up insulin production to overcome the body’s insulin resistance.
“As a counter-measure to maintain insulin supplies, islet beta-cells increase insulin production; however, long-term this strategy fails, rendering the beta-cell unable to produce enough insulin to maintain normal blood sugar,” Stephens said. “The reasons for this failure are not known, and are the major focus of the lab.”
With the funds from the ADA, Dr. Stephens aims to investigate the role of the chromogranin B and VGF proteins in regulating insulin production and storage in the islet beta-cells.
The DoD project will examine the impact diabetic stress has on insulin packaging and storage pathways in the islet beta-cell. Additionally, he will test current diabetes medications to see if these medications aid or diminish beta-cell health in type 2 diabetes.
“To study this process, we use genetically encoded biosensors and high-resolution microscopes to examine how insulin is synthesized, packaged, and stored inside islet beta-cells and how these processes are altered in diabetes,” Stephens said.