UNDER THE MICROSCOPE WITH ARMANDO MENDEZ, PH.D.
Dr. Armando Mendez knows about the ravages of diabetes. Early in his research career, he saw that diabetes was a major risk factor for cardiovascular disease. Then, he further delved into the connection between cardiovascular disease and kidney disease, noting that people with diabetes were at greater risk for both conditions. It became clear that diabetes was a major culprit behind a host of complications that affect just about every organ in the body.
From his first academic appointment at Massachusetts General Hospital in Boston to his long-standing tenure at the Diabetes Research Institute, Dr. Mendez has been studying the damaging effects of diabetes. And, he’s intent on preventing them.
As director of the DRI’s Biomarker and Immunoassay Core Laboratory and a Research Associate Professor of Medicine in the Division of Endocrinology, Metabolism at the University of Miami Miller School of Medicine, he and his team focus on identifying biological signals, or biomarkers, that may predict the onset of these conditions. Using a mix of lifestyle changes, drugs, or the body’s own defenses, they are developing new therapies to stop or delay the onset of these complications in patients.
One of his latest projects focuses on a hormone called oxytocin and its role in protecting the body’s tissues and cells from diabetes destruction. Through his research, he found that oxytocin may even be able to preserve the health and survival of the insulin-producing cells that are destroyed in type 1 diabetes.
What is your area of research at the DRI?
Our work has looked at the disorders associated with both type 1 and type 2 diabetes, primarily studying the effects of cardiovascular disease and lipids (cholesterol and triglycerides) on the body. The overarching goal of these studies is to identify biomarkers, or signs of disease onset, that we can modify with certain interventions to prevent or delay damage to patients.
Another important area of research has been in understanding the role of oxytocin and the oxytocin receptor that is found in most cells throughout the body. For example, in studies of atherosclerosis using research models, we have shown that the group treated with oxytocin had significantly less artery disease compared to the untreated group.
What is oxytocin and why is it important?
Oxytocin is a hormone that is mainly associated with childbirth. However, over the last decade it has become clear that oxytocin is involved in many other functions. In fact, oxytocin receptors – links on the surface of cells that uniquely bind to oxytocin – are found on most of the body’s cells, supporting its broader function.
Our lab was the first to identify the oxytocin receptor on the surface of certain immune cells that are involved in attacking harmful invaders, repairing tissue, and causing inflammation. We showed that when we delivered oxytocin to these immune cells, it acted like a natural anti-inflammatory agent.
We have also shown that oxytocin is present within islets, predominantly in the insulin-producing beta cells but also in other cell types in the islet. Early studies have shown that treating beta cells with oxytocin can improve insulin secretion, suggesting that it plays a role in beta cell health. Other studies have also shown that oxytocin might protect the beta cells during times of high stress.
What are the next steps in your research?
We have developed a specific research model to better understand how oxytocin influences beta cell function and survival under normal conditions and also under different stresses that can influence blood sugar control, beta cell survival and diabetes. As we continue down this research path, we are keenly interested in understanding how oxytocin may affect autoimmunity, beta cell destruction and overall metabolic health. We will be working closely with other DRI investigators that are experts in these areas of research to further inform out studies.
(DRIFocus Fall 2019)