Anchoring Junctions and Cytoskeletal Networks in An

INTRODUCTION Arguably, the biological basis of the mechanical properties observed in epithelial tissues resides within the complex threedimensional arrangement of intercellular junctions that serve to anchor intracellular actin and intermediate filament networks of individual cells. Morphologically, anchoring junctions are often classified as (i) cell-cell junctions: adherens junctions and desmosomes, or (ii) cell-matrix junctions: focal adhesion complexes and hemidesmosomes. Desmosomes and hemidesmosomes are associated with intermediate filament networks, while focal adhesion complexes and adherens junctions are associated with actin networks. To date, experimental evidence is lacking that directly characterizes the mechanical function of specific anchoring junctions and organized cytoskeletal networks as they govern both tissue-level resistance and response (mechanotransduction) to mechanical deformation. As such, histology texts continue to ascribe only general mechanical functions to anchoring junctions, largely based upon rheological studies of the viscoelastic properties of experimentally isolated cytoskeletal proteins [1]. The goal of this research is to more precisely define the constitutive mechanical behavior of anchoring junctions and organized cytoskeletal networks within epithelial tissues as they relate to biological function in states of both health and disease.