John Chappell, assistant professor in the Department of Biomedical Engineering and Mechanics in the College of Engineering and a primary faculty member of the Virginia Tech Carilion Research Institute, has received a National Science Foundation Faculty Early Career Development (CAREER) award to examine the roles that pericytes and endothelial cells play in blood vessel formation and function.

With the five-year, $549,771 CAREER grant, Chappell will use imaging modalities in combination with novel experimental techniques to observe pericyte and endothelial cell dynamics in various cell and tissue microenvironments. As part of the study, he will also build and test computational models to capture how these cells interact in developing and mature blood vessels.

Pericytes and endothelial cells make up an essential part of the vascular unit in all tissues. Among pericytes’ many functions is the stabilization of blood vessels, during which they secrete proteins to coat themselves and also endothelial cells, which line the interior surface of the vessels.

“Up until more recently, endothelial cell biology has been studied almost exclusively, while relatively little has been explored regarding pericytes and their functional roles within that vascular unit,” said Chappell. “Even the scientific definition of a pericyte is still very much in flux. We’re hoping to make contributions that can help clear up some of that confusion.”

With an approach that combines developmental biology with engineering, Chappell and his lab will use experiments to complement and refine computational models to generate – and test – new hypotheses.

“Structurally, when blood vessels form, we want to know how pericytes and endothelial cells work together to form the vessel,” said Chappell. “And then as they’re forming that vessel, how do they regulate how much matrix to secrete as they’re stabilizing the vessel they’ve just made.”

In certain disease conditions, the coating of proteins secreted by pericytes along with other components of the extracellular matrix surrounding endothelial cells can become disrupted. The balance among these components can shift outside of a normal range, which may then damage vessel function.

By studying the basic fundamentals of how pericytes and endothelial cells interact and regulate each other, Chappell hopes to eventually apply those findings to the prevention and treatment of conditions where remodeling vasculature plays a primary role in disease progression. Such conditions include diabetic retinopathy as well as tumor growth and metastasis.

As part of the award, Chappell will work with leaders in STEM education on the Health Sciences and Technology campus in Roanoke to develop supplemental activities and lessons on the scientific method. These activities, for use in primary and secondary classrooms, will include the integration of scientific observations from an active research laboratory in a cross-curricular approach.

Written by Emily Roediger