Single-Cell Biophysics: Measurement, Modulation, and Modeling

Single-Cell Biophysics: Measurement, Modulation, and Modeling

Poster Abstracts

48-POS Board 24 Quantifying Tight Junction Morphology of MDCK Epithelial Cells and Its Implications in Cell-Cell Interactions Ivan Alex P. Lazarte 1,2 , Chen-Ho Wang 1 , Ching chung Hsueh 3 , Li-fan Wu 1 , Yu-Chieh Kuo 1 , Keng-hui Lin 1 .Wan-jung Lin 1 . 1 Academia Sinica, Taipei, Taiwan, 2 National Central University, Taoyuan, Taiwan, 3 National Taiwan University, Taipei, Taiwan. Epithelium comprises the majority of metazoan structures and perform important physiological functions such as protection barrier, secretion, and selective absorption. They are highly polarized and the plasma membranes are separated into apical, lateral, and basal sides. Tight junctions form a continuous belt at the sub-apical location at the borders of two cells as a fence function to maintain the polarity of membrane proteins and seal the paracellular space between cells. The tight junctions are linked to actin cytoskeleton through an adaptor proteins. We found that the tight junctions form tortuous structure as Madin Darby Canine Kidney (MDCK) cells grow into higher confluency on a 2D transwell or as a cyst in 3D matrigel. When we perturbed actin-myosin contractility of MDCK cells by small molecules Y27632 and blebbistatin, the tight junctions become less tortuous, and cell shape changes in terms of height and the apical area. We developed 3D image analysis to quantify the tortuosity of tight junctions and proposed that the morphological change of tight junctions can be indication of apical constriction force and cell- cell tension. By constructing a simple theoretical model by surface evolver to explain the morphology of tight junction affected by the interplay between apical, and lateral tension. Using the endogenous cellular structure for quantifying intercellular force is non-perturbative and the gained knowledge can be used to test current theoretical models which explains the epithelial cell shapes based on basal, lateral, and apical tensions.

122