RRC ID 74476
Author Ebata H, Umeda K, Nishizawa K, Nagao W, Inokuchi S, Sugino Y, Miyamoto T, Mizuno D.
Title Activity-dependent glassy cell mechanics Ⅰ: Mechanical properties measured with active microrheology.
Journal Biophys J
Abstract Active microrheology was conducted in living cells by applying an optical-trapping force to vigorously-fluctuating tracer beads with feedback-tracking technology. The complex shear modulus G(ω)=G'(ω)-iG″(ω) was measured in HeLa cells in an epithelial-like confluent monolayer. We found that G(ω)∝(-iω)1/2 over a wide range of frequencies (1 Hz <ω/2π <10 kHz). Actin disruption and cell-cycle progression from G1 to S and G2 phases only had a limited effect on G(ω) in living cells. On the other hand, G(ω) was found to be dependent on cell metabolism; ATP-depleted cells showed an increased elastic modulus G'(ω) at low frequencies, giving rise to a constant plateau such that G(ω)=G0+A(-iω)1/2 . Both the plateau and the additional frequency dependency ∝(-iω)1/2 of ATP-depleted cells are consistent with a rheological response typical of colloidal jamming. On the other hand, the plateau G0 disappeared in ordinary metabolically active cells, implying that living cells fluidize their internal states such that they approach the critical jamming point.
Published 2023-4-11
DOI 10.1016/j.bpj.2023.04.011
PII S0006-3495(23)00241-2
PMID 37050875
IF 3.854
Resource
Human and Animal Cells HeLa(RCB0007) HeLa/Fucci2(RCB2867)