Description
"Role of Apical Actin-Myosin Network in Regulating Tight Junctions in MDCK Cells
Karen G. Rosal1, Chia-hsuan Lu2, Fu-Lai Wen1, Shawn Ching-Chung Hsueh3, Wen-hsiu Wu4, Yu-Fang Lin5, Mathieu Prouveur6, Thomas Boudier7, Keng-hui Lin1, 8
- Institute of Physics, Academia Sinica, Taipei, Taiwan
- Department of Computer Science and Information Engineering, National Taiwan University,
Taipei, Taiwan - Department of Physics, University of British Columbia, Vancouver, Canada
- Department of Physics, National Tsing-hua University, Hsinchu, Taiwan
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
- Department of Applied Mathematics, Mines ParisTech, Paris, France
- Sorbonne University, Paris, France
- Department of Physics, National Taiwan University, Taipei, Taiwan
Abstract
The apicolateral border of epithelial cells is outlined by the tight junction. This acts like a belt that seals the paracellular spaces when neighboring cells form contact with each other. The actomyosin contractility is regulated by the permeability and morphology of tight junctions based on the purse-string model. Tight junction is close to the apical actin network. This network exerts inward contractions orthogonal to the tight junction. To determine the contribution of apical actin network to the overall integrity of a cell, we laser-ablated the apical surface of polarized MDCK epithelial cells. We found that laser ablation disrupted the apical cytoskeleton network, decreased in-plane tension, and increased the apical surface area. The tight junction also became less tortuous in shape after laser ablation. Upon addition of ROCK inhibitor Y27632, the density of the apical actin network increased and tight junction tortuosity decreased. Our findings show the importance of the apical actin network in exerting in-plane apical tension to regulate tight junction mechanobiology and epithelial cell shape. Currently, we are also exploring super-resolution microscopy to observe the direct connection of the actomyosin network and tight junctions."
