Single-Cell Biophysics: Measurement, Modulation, and Modeling

Single-Cell Biophysics: Measurement, Modulation, and Modeling

Poster Abstracts

122

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

, Ching chung Hsueh

, Li-fan Wu

, Yu-Chieh Kuo

Keng-hui Lin

.Wan-jung Lin

Academia Sinica, Taipei, Taiwan,

National Central University, Taoyuan, Taiwan,

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.