FSU chemist wins major grant to study obesity-diabetes link

A Florida State University researcher has received a major scientific grant to study the chemical processes within the human body that may lead to the development of diabetes. Knowledge gained from Michael Roper's research could lay the foundation for future treatments of a disorder that is reaching pandemic proportions throughout the world, especially in the United States and other developed countries.

Roper and graduate students operate micro-device used in their experiments. (Photo: Steve Leukanech, Department of Chemistry and Biochemistry)

Roper, an assistant professor in FSU's Department of Chemistry and Biochemistry, was recently awarded $1.4 million from the National Institutes of Health to fund a five-year project titled "Microfluidic Devices to Determine Roles of Islet-Secreted Leptin." Essentially, he will try to find out if a protein known as leptin may be secreted by the pancreas, which could then alter the levels of two important hormones, insulin and glucagon, thereby throwing the body's glucose levels, or "blood sugar," off-kilter.

"Within the pancreas are small groups of cells known as islets of Langerhans," Roper said. "One of the jobs of these cells is to sense the levels of glucose in the body and, in response, release hormones such as insulin and glucagon into the bloodstream. Insulin causes the body to store glucose, whereas glucagon causes the liver to release glucose when blood sugar is too low.

"Unfortunately, the molecular mechanisms that control the secretion of these hormones are complicated and not completely known," Roper said. "It has even been shown that in high-glucose conditions, such as those seen in many obese people, the islets of Langerhans will start to produce and secrete proteins such as leptin that are normally produced in the body's fat tissue, which complicates matters even further."

During his five-year study, Roper will work to develop processes to measure the minuscule amounts of leptin and other peptides that are secreted by the pancreas.

"What we are developing are miniaturized devices that hold cells and mimic the conditions inside the body," he said. "We then take what is secreted from the cells and measure the concentrations of multiple peptides, including insulin, glucagon and leptin. The overall objective of this application is the development of technology to quickly and easily measure acute changes in leptin secretion from the islets of Langerhans and determine how this secretion affects the release of traditional peptides such as insulin and glucagon.

"If we could map the relationships between the various peptides and glucose, we would have a better understanding of how secretion is altered in diabetes and how we may be able to change the values back to normal levels," Roper said.

In addition to his NIH grant, Roper is in the second year of a research grant provided by the American Heart Association. That grant, worth $264,000 over three years, is funding a project titled "Microfluidic Perfusion System for Simultaneous Measurement of Glucagon and Insulin Secretion."

To read more about all of the research currently taking place in Roper's FSU lab, visit www.chem.fsu.edu/~roper.

Diabetes is the world's fourth-leading cause of death by disease. An even greater number die from cardiovascular disease made worse by diabetes-related obesity disorders and hypertension. Other health complications can include blindness, stroke, kidney failure and poor circulation.

An estimated 20.8 million Americans—7 percent of our nation's population—suffer from diabetes, a disease in which the body does not produce or properly use insulin. Worldwide, some 246 million people currently have diabetes—and that number is projected to skyrocket to 380 million by the year 2025 as people adopt more sedentary lifestyles and higher-calorie diets.

By Barry Ray