Magnetic Twisting Cytometry

2011 ◽  
Vol 2011 (4) ◽  
pp. pdb.prot5599-pdb.prot5599 ◽  
Author(s):  
K. E. Kasza ◽  
D. Vader ◽  
S. Koster ◽  
N. Wang ◽  
D. A. Weitz
Keyword(s):  
Magnetic Twisting Cytometry

Mechanical properties of rat bone marrow and circulating neutrophils and their responses to inflammatory mediators

Blood ◽  
2002 ◽  
Vol 99 (6) ◽  
pp. 2207-2213 ◽  
Author(s):  
Hajime Saito ◽  
Jean Lai ◽  
Rick Rogers ◽  
Claire M. Doerschuk
Keyword(s):  
Mechanical Properties ◽  
Bone Marrow ◽  
Plasma Membrane ◽  
Complement Protein ◽  
Magnetic Twisting Cytometry ◽  
Pulmonary Capillaries ◽  
Shape Changes ◽  
Rat Bone

Abstract Neutrophils are continuously released from the bone marrow (BM), and this release is accelerated during inflammation. This study compared the mechanical properties of mature neutrophils within the BM and the circulating blood, as well as the role of microtubule rearrangement in the release of neutrophils from the BM in rats. Neutrophils isolated from the BM were stiffer than neutrophils in the circulating blood, using magnetic twisting cytometry. BM neutrophils also contained more F-actin within the submembrane region than circulating neutrophils when examined using confocal microscopy, suggesting that mature quiescent neutrophils within the BM are stiffer than circulating neutrophils because of increased formation of F-actin beneath the plasma membrane. Complement protein 5 fragments or formylmethionyl-leucylphenylalanine (fMLP) induced a stiffening response within 2 minutes that was greater in circulating than in BM neutrophils. This stiffening required F-actin formation within the submembrane region but not microtubule rearrangement in both circulating and BM neutrophils. fMLP-induced shape changes were more pronounced in circulating than in BM neutrophils, which showed fewer and smaller pseudopods and fewer membrane irregularities. In vivo, fMLP induced neutropenia, sequestration of neutrophils within the pulmonary capillaries, and release of neutrophils from the BM. Studies using colchicine demonstrated that rearrangement of microtubules was not required for any of these processes but was required for normal trafficking of neutrophils through the pulmonary capillaries.

scholarly journals Measurement of cell microrheology by magnetic twisting cytometry with frequency domain demodulation

2001 ◽  
Vol 91 (3) ◽  
pp. 1152-1159 ◽  
Author(s):  
Marina Puig-De-Morales ◽  
Mireia Grabulosa ◽  
Jordi Alcaraz ◽  
Joaquim Mullol ◽  
Geoffrey N. Maksym ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Complex Modulus ◽  
Signal To Noise Ratio ◽  
Membrane Receptors ◽  
Elastic Behavior ◽  
Frequency Range ◽  
Bronchial Epithelial ◽  
Coherent Demodulation ◽  
Magnetic Twisting Cytometry ◽  
Cell Micromechanics

Magnetic twisting cytometry (MTC) (Wang N, Butler JP, and Ingber DE, Science260: 1124–1127, 1993) is a useful technique for probing cell micromechanics. The technique is based on twisting ligand-coated magnetic microbeads bound to membrane receptors and measuring the resulting bead rotation with a magnetometer. Owing to the low signal-to-noise ratio, however, the magnetic signal must be modulated, which is accomplished by spinning the sample at ∼10 Hz. Present demodulation approaches limit the MTC range to frequencies <0.5 Hz. We propose a novel demodulation algorithm to expand the frequency range of MTC measurements to higher frequencies. The algorithm is based on coherent demodulation in the frequency domain, and its frequency range is limited only by the dynamic response of the magnetometer. Using the new algorithm, we measured the complex modulus of elasticity (G*) of cultured human bronchial epithelial cells (BEAS-2B) from 0.03 to 16 Hz. Cells were cultured in supplemented RPMI medium, and ferromagnetic beads (∼5 μm) coated with an RGD peptide were bound to the cell membrane. Both the storage (G′, real part of G*) and loss (G", imaginary part of G*) moduli increased with frequency as ωα (2π × frequency) with α ≈ ¼. The ratio G"/G′ was ∼0.5 and varied little with frequency. Thus the cells exhibited a predominantly elastic behavior with a weak power law of frequency and a nearly constant proportion of elastic vs. frictional stresses, implying that the mechanical behavior conformed to the so-called structural damping (or constant-phase) law (Maksym GN, Fabry B, Butler JP, Navajas D, Tschumperlin DJ, LaPorte JD, and Fredberg JJ, J Appl Physiol 89: 1619–1632, 2000). We conclude that frequency domain demodulation dramatically increases the frequency range that can be probed with MTC and reveals that the mechanics of these cells conforms to constant-phase behavior over a range of frequencies approaching three decades.

Probing transmembrane mechanical coupling and cytomechanics using magnetic twisting cytometry

1995 ◽  
Vol 73 (7-8) ◽  
pp. 327-335 ◽  
Author(s):  
Ning Wang ◽  
Donald E. Ingber
Keyword(s):  
Cell Surface ◽  
Cell Shape ◽  
Magnetic Beads ◽  
Mechanical Response ◽  
Scavenger Receptor ◽  
Specific Cell ◽  
Transmembrane Receptors ◽  
Mechanical Coupling ◽  
Magnetic Twisting Cytometry ◽  
Force Transfer

We recently developed a magnetic twisting cytometry technique that allows us to apply controlled mechanical stresses to specific cell surface receptors using ligand-coated ferromagnetic microbeads and to simultaneously measure the mechanical response in living cells. Using this technique, we have previously shown the following: (i) β1 integrin receptors mediate mechanical force transfer across the cell surface and to the cytoskeleton, whereas other transmembrane receptors (e.g., scavenger receptors) do not; (ii) cytoskeletal stiffness increases in direct proportion to the level of stress applied to integrins; and (iii) the slope of this linear stiffening response differs depending on the shape of the cell. We now show that different integrins (β1, αVβ3, αV, α5, α2) and other transmembrane receptors (scavenger receptor, platelet endothelial cell adhesion molecule) differ in their ability to mediate force transfer across the cell surface. In addition, the linear stiffening behavior previously observed in endothelial cells was found to be shared by other cell types. Finally, we demonstrate that dynamic changes in cell shape that occur during both cell spreading and retraction are accompanied by coordinate changes in cytoskeletal stiffness. Taken together, these results suggest that the magnetic twisting cytometry technique may be a powerful and versatile tool for studies analyzing the molecular basis of transmembrane mechanical coupling to the cytoskeleton as well as dynamic relations between changes in cytoskeletal structure and alterations in cell form and function.Key words: integrins, mechanical stress, magnetic beads, cytoskeleton, cell shape.

scholarly journals Using Magnetic Twisting Cytometry to Study Monocyte Activation

2011 ◽  
Vol 100 (3) ◽  
pp. 303a
Author(s):  
Matthias Irmscher ◽  
Holger Kress ◽  
Arthur M. de Jong ◽  
Menno W.J. Prins
Keyword(s):  
Monocyte Activation ◽  
Magnetic Twisting Cytometry

Implications of heterogeneous bead behavior on cell mechanical properties measured with magnetic twisting cytometry

1999 ◽  
Vol 194 (1-3) ◽  
pp. 120-125 ◽  
Author(s):  
Ben Fabry ◽  
Geoffrey N. Maksym ◽  
Rolf D. Hubmayr ◽  
James P. Butler ◽  
Jeffrey J. Fredberg
Keyword(s):  
Mechanical Properties ◽  
Magnetic Twisting Cytometry ◽  
Cell Mechanical Properties

Magnetic Twisting Cytometry

2018 ◽  
pp. 59-92
Author(s):  
Daniel Isabey ◽  
Christelle Angely ◽  
Adam Caluch ◽  
Bruno Louis ◽  
Gabriel Pelle
Keyword(s):  
Magnetic Twisting Cytometry

Development and Calibration of an Optical Magnetic Twisting Cytometry for Studying Nano-Dynamics of Living Cells

2010 ◽  
Vol 160-162 ◽  
pp. 1535-1540
Author(s):  
Feng Lin ◽  
Xue Mei Jiang ◽  
Qing Feng Liao ◽  
Ai Jing Song ◽  
Lin Hong Deng
Keyword(s):  
Cell Surface ◽  
Respiratory Disease ◽  
Mechanical Stimulation ◽  
Cell Mechanics ◽  
Noise Level ◽  
Living Cells ◽  
Software Integration ◽  
Magnetic Twisting Cytometry ◽  
Noise Characteristics

We report the development and calibration of a built optical magnetic twisting cytometry (OMTC) system. The development includes hardware assembly and software integration. The system has been calibrated in terms of its noise characteristics. The results demonstrated that in current experimental condition the system performed satisfactorily with negligible noise level. The ASM cell also exhibited stiffening in response to mechanical stimulation due to continuous twisting of beads on the cell surface, providing a useful technique for studying the role of ASM cell mechanics in pathogenesis of respiratory disease such as asthma.

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