TY - JOUR
T1 - Myosin II activity softens cells in suspension
AU - Chan, Chii J.
AU - Ekpenyong, Andrew E.
AU - Golfier, Stefan
AU - Li, Wenhong
AU - Chalut, Kevin J.
AU - Otto, Oliver
AU - Elgeti, Jens
AU - Guck, Jochen
AU - Lautenschläger, Franziska
N1 - Funding Information:
The authors acknowledge financial support from the European Community’s Seventh Framework Program (grant No. FP7/2007-2013) under grant agreement No. TRANSPOL 264399 (to C.J.C.), Cambridge Gates Scholarship (to F.L.), Cambridge Commonwealth Bursary and Duke of Edinburgh Scholarship (to A.E.E.), and the LightTouch Starting Investigator Grant of the European Research Council and the Humboldt-Professorship from the Alexander-von-Humboldt Foundation (to J.G.).
PY - 2015/4/21
Y1 - 2015/4/21
N2 - 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.
AB - 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.
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U2 - 10.1016/j.bpj.2015.03.009
DO - 10.1016/j.bpj.2015.03.009
M3 - Article
C2 - 25902426
AN - SCOPUS:84928254421
VL - 108
SP - 1856
EP - 1869
JO - Biophysical Journal
JF - Biophysical Journal
SN - 0006-3495
IS - 8
ER -