Polarized light retardation analysis allows for the evaluation of tension in individual stress fibers

Shukei Sugita; Masatoshi Hozaki; Tsubasa S Matsui; Kazuaki Nagayama; Shinji Deguchi; Masanori Nakamura

doi:10.1016/j.bbrc.2022.06.066

Polarized light retardation analysis allows for the evaluation of tension in individual stress fibers

Biochem Biophys Res Commun. 2022 Sep 10:620:49-55. doi: 10.1016/j.bbrc.2022.06.066. Epub 2022 Jun 24.

Authors

Shukei Sugita¹, Masatoshi Hozaki², Tsubasa S Matsui³, Kazuaki Nagayama⁴, Shinji Deguchi³, Masanori Nakamura⁵

Affiliations

¹ Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan; Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan. Electronic address: sugita.shukei@nitech.ac.jp.
² Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan.
³ Division of Bioengineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan.
⁴ Department of Mechanical Systems Engineering, Ibaraki University, Nakanarusawa-cho, Hitachi, 316-8511, Japan.
⁵ Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan; Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan; Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan.

PMID: 35777134
DOI: 10.1016/j.bbrc.2022.06.066

Abstract

The tension in the stress fibers (SFs) of cells plays a pivotal role in determining biological processes such as cell migration, morphological formation, and protein synthesis. Our previous research developed a method to evaluate the cellular contraction force generated in SFs based on photoelasticity-associated retardation of polarized light; however, we employed live cells, which could have caused an increase in retardation and not contraction force. Therefore, the present study aimed to confirm that polarized light retardation increases inherently due to contraction, regardless of cell activity. We also explored the reason why retardation increased with SF contractions. We used SFs physically isolated from vascular smooth muscle cells to stop cell activity. The retardation of SFs was measured after ATP administration, responsible for contracting SFs. The SFs were imaged under optical and electron microscopes to measure SF length, width, and retardation. The retardation of isolated SFs after ATP administration was significantly higher than before. Thus, we confirmed that retardation increased with elevated tension in individual SFs. Furthermore, the SF diameter decreased while the SF length remained almost constant. Thus, we conclude that a contraction force-driven increase in the density of SFs is the main factor for the rise in polarized light retardation.

Keywords: Mechanobiology; Photoelasticity; Polscope; Stress fibers; Tension.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adenosine Triphosphate / metabolism
Cell Movement
Myocytes, Smooth Muscle* / physiology
Stress Fibers* / metabolism
Stress, Mechanical

Substances

Adenosine Triphosphate