Written by Hannah Weems

Prasanna Krishnamurthy, Ph.D., an associate professor of Biomedical Engineering, co-authored a study in April that finds a link between brain health and heart disease. Previously, clinical studies have shown a strong connection between depression and the risk for heart disease. Those specific mechanisms, however, are yet to be understood. The recent lab study found cardiac glycosaminoglycans and structural alterations during chronic stress-induced depression-like behavior in mice.

In Krisnamurthy's study, mice were assigned to a non-stress group and a chronic mild stress group. Mice in stress were exposed to a series of mild, unpredictable stressors for seven weeks. These mice displayed a significant decrease in protein expression of hippocampal brain-derived neutrophic factor (BDNF) and exhibited depression-like behavioral changes, such as learned helplessness and decreased explorative behavior.

While cardiac function remained the same in both groups, the mice under stress exhibited an increased left ventricular wall thickness. In comparison to the mice in the non-stress group, these mice demonstrated an increase in cardiomyocyte cross-sectional area, and an associated decrease in brain-derived neurotrophic. The authors note that further research is needed to explore the relationship between cardiac GAGs biology and myocardial remodeling as a causal mechanism that underlie cardiovascular complications in patients with major depressive disorder.

This study, “Cardiac glycosaminoglycans and structural alterations during chronic stress-induced depression-like behavior in mice,” published in the peer-reviewed American Journal of Physiology Heart and Circulatory Physiology, is one of the first of its kind to characterize cardiac proteoglycan/glycosaminoglycan profile in response to depression-like behavior and determine if alterations in glycosaminoglycan profile are associated with structural changes in the heart.

Krishnamurthy and his team’s next step is to identify molecular signatures that mediate cardiac pathology during mental disorder. Research investigations are underway to study the role of novel mediators in causing heart disease and to develop potential treatment strategies.