image: Patrick Calhoun (right), a graduate student of biological sciences in Virginia Tech's College of Science, was awarded an American Heart Association fellowship to pursue cardiac research in the laboratory of James Smyth (left), an assistant professor at the Virginia Tech Carilion Research Institute. view more
Credit: Virginia Tech Carilion Research Institute
The American Heart Association awarded Patrick Calhoun, a biological sciences graduate student, a predoctoral fellowship to carry out his dissertation research at the Virginia Tech Carilion Research Institute in the laboratory of James Smyth.
An assistant professor at VTCRI, Smyth is also a member of the Institute's Center for Heart and Regenerative Medicine Research and an assistant professor in the Department of Biological Sciences.
Under Smyth's mentorship, Calhoun will use the $89,000 award to support his ongoing research into how a viral infection can lead to cardiac death.
Calhoun is investigating how a viral infection that causes a mild cough in the lungs may have a much more severe effect in heart tissue. Cardiac cells communicate with one another through channels called gap junctions to keep the heart in sync.
"A viral infection can stop communication between heart cells, which can lead to arrhythmia," Calhoun said, noting that he specifically studies adenovirus, an increasingly known contributing factor in several sudden cardiac death cases.
In people less than 35 years old, sudden cardiac death is one of the largest contributors to heart disease, the leading cause of death in the United States. It disproportionately affects athletes and children, and researchers are only now beginning to understand why it occurs.
Calhoun is investigating the effect adenovirus has on gap junctions, as well as studying how gap junctions might be manipulated to mitigate the interruption to communication between cells.
Smyth and his team previously demonstrated that adenovirus attacks the components of gap junctions -- proteins called Connexin 43 that are the most abundant in the heart. In Connexin 43-free cells, the virus replicates more rapidly as a result of decreased cell-to-cell communication. In cells engineered to have robustly increased levels of Connexin 43, the infection cycle slowed.
"The ability of the cell to stop the virus hinged on its intercellular communication, which surprised us," said Smyth, who is also an assistant professor of biological sciences in Virginia Tech's College of Science. "We plan to learn even more from this exquisitely efficient virus -- it has to target key regulator hubs and disable them quickly. Every move counts."
Smyth and Calhoun plan to examine exactly how the virus targets and disables Connexin 43.
"All cardiac disease has this common theme of intercellular communication breakdown," Calhoun said. "If we can understand the pathways adenovirus uses in sudden cardiac death, we might be able to therapeutically target them in other forms of cardiac disease, too."
Calhoun also said that the American Heart Association's support was a welcome validation of the research and its potential given how competitive such awards are.
"I'm thankful the American Heart Association is just as excited as we are about this work," Calhoun said. "I'm also grateful for the support and encouragement they're giving me to pursue this project."
Calhoun earned his bachelor's degree in biological sciences from Virginia Tech, as well as an associate's degree from Virginia Western Community College. Originally from Niceville, Florida, Calhoun served in the U.S. Army before moving to Roanoke and joining Smyth's lab at the VTCRI.
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