Abstract
Vascular smooth muscle cells (VSMCs) have two distinct phenotypes: contractile and synthetic. The major difference between these phenotypes lies in the magnitude of the contractile force produced by the cell. Although traction force microscopy (TFM) is often used to evaluate cellular contractile force, this method requires complex preprocessing and a sufficiently compliant substrate. To evaluate the contractile force and the phenotype of living VSMCs with minimal effort and in a manner independent of the substrate stiffness, we propose a photoelasticity-based method using retardation, which is related to the difference between the first and second principal stresses and their orientation. The results demonstrate that actin filaments co-localize with areas of high retardation in cells, indicating that the retardation of VSMCs is promoted by actin filaments. The retardation of cells treated with calyculin A and Y-27632 tended to be larger and smaller, respectively, than that of control cells. Cell traction force significantly correlates with total cell retardation (r2 = 0.38). The retardation of contractile VSMCs (passage 2) was significantly higher than that of synthetic VSMCs (passage 12). These results indicate that cell retardation can be used to assess cell contractile force and, thus, determine the phenotype of VSMCs.
Highlights
Some cells generate a contractile force through stress fibres (SFs), composed of actin and myosin filaments, by sliding bundles of myosin filaments over bundles of actin filaments
This study demonstrates that the retardation of Vascular smooth muscle cells (VSMCs) is correlated with their contractility
Cell retardation is well co-localized with SFs, which are considered to generate the contraction force of VSMCs
Summary
Some cells generate a contractile force through stress fibres (SFs), composed of actin and myosin filaments, by sliding bundles of myosin filaments over bundles of actin filaments. Traction force microscopy (TFM)[14] is a representative method for determining the CTF exerted by a cell on a substrate surface. In TFM, microspheres are embedded in a compliant substrate, and their displacement by cell contraction is used to measure the strain and determine the cell CTF. The main drawback of TFM and the methods evaluating micro-pillar deformation and substrate wrinkles is that cells must be sparsely seeded and the substrate must be compliant enough to allow large deformation. White colours in the merged images show the co-localization between the cytoskeleton and retardation. Because the extracellular matrix stiffness influences VSMC phenotype[18,19], the phenotype of cells cultured on a soft substrate are likely to differ from those of cells in natural conditions
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
