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Updated: Jul 18, 2026

Simplified, High-throughput Analysis of Single-cell Contractility using Micropatterned Elastomers
Published on: April 8, 2022
Alpha-smooth muscle actin expression enhances cell traction force
Jianxin Chen1, Hongxia Li, Nirmala SundarRaj
1Department of Orthopaedic Surgery, MechanoBiology Laboratory, University of Pittsburgh, Pennsylvania 15213, USA.
Abstract:
Using an established corneal stromal cell differentiation model, we manipulated alpha-smooth muscle actin (alpha-SMA) protein expression levels in fibroblasts by treating them with TGF-beta1, bFGF, TGF-beta type I receptor inhibitor (SB-431542), and siRNA against alpha-SMA. The corresponding cell traction forces (CTFs) were determined by cell traction force microscopy. With all these treatments, we found that alpha-SMA is not required for CTF induction, but its expression upregulates CTF. This upregulation involves the modification of stress fibers but does not appear to relate to non-muscle myosin II expression or beta-actin expression. Moreover, there exists a linear relationship between alpha-SMA protein expression level and CTF magnitude. Finally, CTFs were found to vary among a population of myofibroblasts, suggesting that alpha-SMA protein expression levels of individual cells also vary.
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