Subha Bhaskaran publishes article based on her PhD dissertation

According to the National Diabetes Education Program, “diabetes is a group of diseases marked by high levels of blood glucose resulting from defects in insulin production, insulin action, or both. Diabetes can lead to serious complications and premature death.” Over 25 million Americans have diabetes, which is over 8 percent of the population. Assistant Professor Amy Banes-Berceli, of the Department of Biological Sciences, and her team is hard at work trying to understand and cure this serious disease. In the January 15 issue of the American Journal of Physiology, they published a article titled “Molecular Interactions of Serotonin (5-HT) and Endothelin-1 in Vascular Smooth Muscle Cells: In Vitro and Ex Vivo Analyses” (Am. J. Physiol., Volume 306, Pages C143-C151, 2014). The introduction to their paper describes their study and its goals.

“Diabetes mellitus is a leading cause of renal disease [a disease of the kidney] and an independent risk factor for cardiovascular disease complications in the United States. Accumulating evidence suggests that serotonin [5-hydroxytryptamine (5-HT)], a well-known mitogen and a potent vasoconstrictor, may also stimulate pathological processes in diabetes. 5-HT has been associated with cardiovascular diseases such as atherosclerosis and pulmonary hypertension, but it has been overlooked in some diseases because of its low circulating physiological levels (estimated to be in the 10⁻⁹ M range) and a lack of understanding of the roles of 5-HT in the peripheral systems. One way by which physiological levels of 5-HT may have an effect on vascular tone is through the interaction with other vasoactive substances including ET-1 [endothelin-1], which could exacerbate the pathophysiological mechanisms….

We tested the hypothesis that the interaction between 5-HT and ET-1 in VSMC [vascular smooth muscle cells, which line the inner surface of blood vessels] at physiological concentrations would cause enhanced activation of both p42/44 MAPK [mitogen-activated protein kinase] and JAK2 [Janus kinase 2] signaling pathways in vitro for acute preincubations of the cultured VSMCs with 5-HT and/or ET-1 that could contribute to altered cellular functions especially in hyperglycemic conditions. We also hypothesized that the physiological levels of 5-HT and ET-1 interact to stimulate an increase in the contractile response in arteries ex vivo that may lead to altered vascular functions that may contribute to early development of cardiovascular injury as a consequence of diabetes.”

The lead author on the study was Subha Bhaskaran, who obtained her PhD from the Biomedical Sciences: Biological Communication program last year, and now teaches for the Department of Biological Sciences. For her dissertation she studied “Molecular Mechanisms of Serotonin (5-HT) Involvement in Diabetic Complications.” Also contributing to the study was Jeremy Zaluski (BS 2011), formerly an undergraduate biology major working with Banes-Berceli.

The research was supported by a grant (R00HL91177) to Banes-Berceli from the National Heart, Lung, and Blood Institute, part of the National Institutes of Health.