Coordinated endothelial cell networking, a component of angiogenesis, is required to form and refine the exquisite fractal network that emerges in the developing and mature lung to facilitate efficient gas exchange from birth onwards. Real-time imaging of endothelial cells cultured within a specialized extracellular matrix (ECM) microenvironment, designated the basement membrane, formed the basis of this project.
The angiogenic networking behavior of lung mesenchymal cells, designated RFL-6 or MFLM-4 cells, which have ability to transform into networking endothelial cells in response to basement membrane proteins was evaluated in contrasting conditions: with or without Prx-1, a gene that enhances networking. When Prx-1 is absent, cells formed clustered on basement membrane material. On the other hand, when Prx-1 was present, cells formed branched networks on this matrix.
The network formations are also influenced by the topological geometries found within the underlying ECM. With the help of metalloproteinase, cell behaviors could either dissolve the existing extracellular matrix or regenerate and attach new structures to the matrix.
Thus, the roles played by Prx-1 (code) and the ECM (environment) are highly influential in creating these network morphologies by endothelial cells (components).
This collaboration between code, environment and component has to operate on a series of scales which start with the single cells paring, grouping and clustering, and eventually reconfiguring these clusters into larger networks which create the lung vasculature. By studying the relationship between these effectors, we can observe how inter-scalar relationships occur and move from the micro to the macro.
UPenn Dept of ARCH999, Independent Study, Spring 09 (Sabin & Jones).
Joshua Freese, Shuni Feng
Jeffrey Nesbit (initial studies)