TY - JOUR
T1 - Mechanical strain increases cell stiffness through cytoskeletal filament reorganization
AU - Smith, Paul G.
AU - Deng, Linhong
AU - Fredberg, Jeffrey J.
AU - Maksym, Geoffrey N.
PY - 2003/8/1
Y1 - 2003/8/1
N2 - We tested the hypothesis that cytoskeletal reorganization induced by cyclic strain increases cytoskeletal stiffness (G′). G′ was measured by optical magnetic twisting cytometry in control cells and cells that had received mechanical strain for 10-12 days. G′ was measured before and after both contractile and relaxant agonists, and in the strained cells both parallel (Para) and perpendicular (Perp) to the aligned cytoskeleton. Before activation, G′ Para was 24 ± 5% (± SE) greater compared with Perp (P < 0.05), and 35% ± 6 greater compared with control (Cont, P < 0.01). The difference between strained and control cells was enhanced by KCl, increasing G′ 171 ± 7% Para compared with 125 ± 6% Perp and 129 ± 8% Cont (P < 10-5 both cases). The decrease in G′ from baseline due to relaxant agonists isoproterenol and dibutyryl cAMP was similar in all groups. Long-term oscillatory loading of airway smooth muscle (ASM) cells caused stiffness to increase and become anisotropic. These findings are consistent with the hypothesis that cytoskeletal reorganization can enhance ASM stiffness and contractility. They imply, furthermore, that oscillatory loading of ASM may contribute to airway narrowing and failure of airway dilation in asthma.
AB - We tested the hypothesis that cytoskeletal reorganization induced by cyclic strain increases cytoskeletal stiffness (G′). G′ was measured by optical magnetic twisting cytometry in control cells and cells that had received mechanical strain for 10-12 days. G′ was measured before and after both contractile and relaxant agonists, and in the strained cells both parallel (Para) and perpendicular (Perp) to the aligned cytoskeleton. Before activation, G′ Para was 24 ± 5% (± SE) greater compared with Perp (P < 0.05), and 35% ± 6 greater compared with control (Cont, P < 0.01). The difference between strained and control cells was enhanced by KCl, increasing G′ 171 ± 7% Para compared with 125 ± 6% Perp and 129 ± 8% Cont (P < 10-5 both cases). The decrease in G′ from baseline due to relaxant agonists isoproterenol and dibutyryl cAMP was similar in all groups. Long-term oscillatory loading of airway smooth muscle (ASM) cells caused stiffness to increase and become anisotropic. These findings are consistent with the hypothesis that cytoskeletal reorganization can enhance ASM stiffness and contractility. They imply, furthermore, that oscillatory loading of ASM may contribute to airway narrowing and failure of airway dilation in asthma.
KW - Airway smooth muscle cell
KW - Anisotropy
KW - Optical magnetic twisting cytometry
KW - Plasticity
KW - Smooth muscle contraction
UR - http://www.scopus.com/inward/record.url?scp=0041843897&partnerID=8YFLogxK
U2 - 10.1152/ajplung.00329.2002
DO - 10.1152/ajplung.00329.2002
M3 - Article
C2 - 12704020
AN - SCOPUS:0041843897
SN - 1040-0605
VL - 285
SP - L456-L463
JO - American Journal of Physiology - Lung Cellular and Molecular Physiology
JF - American Journal of Physiology - Lung Cellular and Molecular Physiology
IS - 2 29-2
ER -