Developing platforms to investigate mechanotransduction during wound healing

Wound healing in adult skin tissue lacks the ability to recapitulate uninjured tissue structure-function, forming instead fibrotic tissue with limited functionality. The extracellular matrix regulates forces on a cell- and tissue-specific level. Fibronectin, a mechanically regulated extracellular matrix protein that binds integrins, growth factors, and other matrix proteins, is an irreplaceable modulator of wound healing. Despite this, our understanding of fibronectin isoforms, their spatiotemporal dynamics during matrix assembly, and their role in regulating mechanotransduction to direct cell migration to dictate normal or fibrotic wound healing remains critically understudied. The isoform EDA-fibronectin contains an Extra Domain A insert that is only expressed in adult tissue during wound healing or pathological processes. EDA-fibronectin is essential for wound closure, has been linked to tissue regeneration, but conversely also linked to fibrosis. How EDA-fibronectin regulates wound fate remains understudied, especially if EDA-fibronectin differentially regulates mechanotransduction signaling pathways driving either normal or fibrotic wound healing. This proposal seeks to: 1) study the role of substrate stiffnesses mimicking normal or fibrotic wounds in EDA-fibronectin matrix assembly and organization during wound healing; 2) examine the role of focal adhesion kinase in regulating cell migration behavior during wound closure; and 3) engineer a novel strainable wound closure assay to evaluate how strain alters matrix-mediated signaling during fibrotic wound closure. These projects seek to incorporate physiologically relevant stiffness and strain in a wound healing assay to investigate the importance of EDA-fibronectin structure-function during normal and fibrotic wound healing, shifting the focus in wound healing from repair to regeneration.