Abstract
The mechanical behavior of the human parasite Entamoeba histolytica plays a major role in the invasive process of host tissues and vessels. In this study, we set up an intracellular rheological technique derived from magnetic tweezers to measure the viscoelastic properties within living amoebae. The experimental setup combines two magnetic fields at 90° from each other and is adapted to an inverted microscope, which allows monitoring of the rotation of pairs of magnetic phagosomes. We observe either the response of the phagosome pair to an instantaneous 45° rotation of the magnetic field or the response to a permanent uniform rotation of the field at a given frequency. By the first method, we concluded that the phagosome pairs experience a soft viscoelastic medium, represented by the same mechanical model previously described for the cytoplasm of Dictyostelium discoideum [Feneberg et al. in Eur Biophys J 30(4):284–294 2001]. By the second method, the permanent rotation of a pair allowed us to apply a constant shear rate and to calculate the apparent viscosity of the cytoplasm. As found for entangled polymers, the viscosity decreases with the shear rate applied (shear-thinning behavior) and exhibits a power-law-type thinning, with a corresponding exponent of 0.65. Treatment of amoeba with drugs that affect the actin polymer content demonstrated that the shear-thinning behavior of the cytoplasm depends on the presence of an intact actin cytoskeleton. These data present a physiologic relevance for Entamoeba histolytica virulence. The shear-thinning behavior could facilitate cytoplasm streamings during cell movement and cell deformation, under important shear experienced by the amoeba during the invasion of human tissues. In this study, we also investigated the role of the actin-based motor myosin II and concluded that myosin II stiffens the F-actin gel in living parasites likely by its cross-linking activity.
Similar content being viewed by others
References
Allain C, Cloitre M, Perrot P (1997) Experimental investigation and scaling law analysis of die swell in semi-dilute polymer solutions. J Non-Newtonian Fluid Mech 73:51–66
Arhets P, Olivo JC, Gounon P, Sansonetti P, Guillen N (1998) Virulence and functions of myosin II are inhibited by overexpression of light meromyosin in Entamoeba histolytica. Mol Biol Cell 9(6):1537–1547
Bausch AR, Moller W, Sackmann E (1999) Measurement of local viscoelasticity and forces in living cells by magnetic tweezers. Biophys J 76(1):573–579
Bird RB, Amstrong RC, Hassager O (1987) Dynamics of polymeric liquids, vol 1. Fluid mechanics. Wiley, New York
Burns CG, Reedy M, Heuser J, De Lozanne A (1995) Expression of light meromyosin in Dictyostelium blocks normal myosin II function. J Cell Biol 130(3):605–612
Buxbaum RE, Dennerll T, Weiss S, Heidemann SR (1987) F-actin and microtubule suspensions as indeterminate fluids. Science 20235(4795):1511–1514
Coudrier E, Amblard F, Zimmer C, Roux P, Olivo-Marin J-C, Rigothier M-C, Guillen N (2004) Myosin II and the Gal-GalNAc lectin play a crucial role in tissue invasion by Entamoeba histolytica. Cell Microbiol (in press)
Feneberg W, Westphal M, Sackmann E (2001) Dictyostelium cells’ cytoplasm as an active viscoplastic body. Eur Biophys J 30(4):284–294
Graessley W (1967) Viscosity of entangling polydispers polymers. J Chem Phys 47:1942–1953
Hamann L, Nickel R, Tannich E (1995) Transfection and continuous expression of heterologous genes in the protozoan parasite Entamoeba histolytica. Proc Natl Acad Sci USA 92:8975–8979
Humphrey D, Duggan C, Saha D, Smith D, Käs J (2002) Active fluidization of polymer networks through molecular motors. Nature 416:413–416
Janmey PA, Hvidt S, Peetermans J, Lamb J, Ferry JD, Stossel TP (1988) Viscoelasticity of F-actin and F-actin/gelsolin complexes. Biochemistry 27:8218–8227
Janmey PA, Hvidt S, Lamb J, Stossel TP (1990) Resemblance of actin-binding protein/actin gels to covalently crosslinked networks. Nature 345:89–92
Janson LW, Kolega J, Taylor DL (1991) Modulation of contraction by gelation/solation in a reconstituted motile model. J Cell Biol 153:1479–1497
Kolega J, Janson LW, Taylor DL (1991) The role of solation-concentration coupling in regulating stress fiber dynamics in nonmuscle cells. J Cell Biol 114:993–1003
Laevsky G, Knecht DA (2003) Cross-linking of actin filaments by myosin II is a major contributor to cortical integrity and cell motility in restrictive environments. J Cell Sci 116(Pt18):3761–3770
Maksym GN, Fabry B, Butler JP, Navajas D, Tschumperlin DJ, Laporte JD, Fredberg JJ (2000) Mechanical properties of cultured human airway smooth muscle cells from 0.05 to 0.4 Hz. J Appl Physiol 89(4):1619–1632
Marion S, Wilhelm C, Voigt H, Bacri JC, Guillen N (2004) Overexpression of myosin IB in living Entamoeba histolytica enhances cytoplasm viscosity and reduces phagocytosis. J Cell Sci 117(Pt 15):3271–3279
Moller W, Nemoto I, Matsuzaki T, Hofer T, Heyder J (2000) Magnetic phagosome motion in J774A.1 macrophages: influence of cytoskeletal drugs. Biophys J 79:720–730
Shelden E, Knecht DA (1995) Mutants lacking myosin II cannot resist forces generated during multicellular morphogenesis. J Cell Sci 108(Pt 3):1105–1115
Stossel TP (1993) On the crowling of animal cells. Science 260:1086–1094
Tsai MA, Hammer DA (1997) Rheology of rat basophilic leukemia cells. Ann Biomed Eng 25(1):62–68
Tsai MA, Frank RS, Waugh RE (1993) Passive mechanical behavior of human neutrophils: power-law fluid. Biophys J 65(5):2078–2088
Tseng Y, Schafer BW, Almo SC, Wirtz D (2002) Functional synergy of actin filament cross-linking proteins. J Biol Chem 277:25609–25616
Tseng Y, An MK, Esue O, Wirtz D (2004) The bimodal role of filamin in controlling the architecture and mechanics of F-actin network. J Biol Chem 279:1819–1826
Wachsstock DH, Schwarz WH, Pollard TD (1994) Cross-linker dynamics determine the mechanical properties of actin gels. Biophys J 66:801–809
Watanabe H (1999) Viscoelasticity and dynamics of entangled polymers. Prog Polym Sci 24(9):1253–1403
Whilhelm C, Browaeys J, Ponton A, Bacri JC (2003) Rotational magnetic particles microrheology: the Maxwellian case. Phys Review E 67:061908
Xu CJ, Wirtz D, Pollard TD (1998) Dynamic cross-linking by alpha-actinin determines the mechanical properties of actin filament networks. J Biol Chem 273:9570–9576
Zaner KS, Stossel TP (1982) Some perspectives on the viscosity of actin filaments. J Cell Biol 93(3):987–991
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Marion, S., Guillen, N., Bacri, JC. et al. Acto-myosin cytoskeleton dependent viscosity and shear-thinning behavior of the amoeba cytoplasm. Eur Biophys J 34, 262–272 (2005). https://doi.org/10.1007/s00249-004-0449-5
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00249-004-0449-5