Myosin II activity softens cells in suspension

Chii J. Chan, Andrew Ekpenyong, Stefan Golfier, Wenhong Li, Kevin J. Chalut, Oliver Otto, Jens Elgeti, Jochen Guck, Franziska Lautenschläger

Research output: Contribution to journalArticle

47 Scopus citations

Abstract

The cellular cytoskeleton is crucial for many cellular functions such as cell motility and wound healing, as well as other processes that require shape change or force generation. Actin is one cytoskeleton component that regulates cell mechanics. Important properties driving this regulation include the amount of actin, its level of cross-linking, and its coordination with the activity of specific molecular motors like myosin. While studies investigating the contribution of myosin activity to cell mechanics have been performed on cells attached to a substrate, we investigated mechanical properties of cells in suspension. To do this, we used multiple probes for cell mechanics including a microfluidic optical stretcher, a microfluidic microcirculation mimetic, and real-time deformability cytometry. We found that nonadherent blood cells, cells arrested in mitosis, and naturally adherent cells brought into suspension, stiffen and become more solidlike upon myosin inhibition across multiple timescales (milliseconds to minutes). Our results hold across several pharmacological and genetic perturbations targeting myosin. Our findings suggest that myosin II activity contributes to increased whole-cell compliance and fluidity. This finding is contrary to what has been reported for cells attached to a substrate, which stiffen via active myosin driven prestress. Our results establish the importance of myosin II as an active component in modulating suspended cell mechanics, with a functional role distinctly different from that for substrate-adhered cells.

Original languageEnglish
Pages (from-to)1856-1869
Number of pages14
JournalBiophysical Journal
Volume108
Issue number8
DOIs
StatePublished - Apr 21 2015
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Biophysics

Cite this

Chan, C. J., Ekpenyong, A., Golfier, S., Li, W., Chalut, K. J., Otto, O., Elgeti, J., Guck, J., & Lautenschläger, F. (2015). Myosin II activity softens cells in suspension. Biophysical Journal, 108(8), 1856-1869. https://doi.org/10.1016/j.bpj.2015.03.009