to BioTechniques free email alert service to receive content updates.
Cyclic stretch of the substratum using a shape-memory alloy induces directional migration in Dictyostelium cells
 
Yoshiaki Iwadate1,2 and Shigehiko Yumura1
Full Text (PDF)
Supplementary Material
Supplementary Movie 1. Motion of stretching device using SMA as a power source. (.mov)
To generate the power to stretch the elastic sheet, 4 pieces of coiled SMA were connected in parallel to the left edge of the sheet. The time cycle was 30 s. The movie is shown 5× faster than real time.
Supplementary Movie 2. Dictyostelium cells under the cyclic stretching stimuli. (.mov)
This movie was prepared for demonstration. The densities of cells in this movie were higher than that of the trajectory measurement (see Figure 2 in the main text). The time cycle was 30 s. The movie is shown 10× faster than real time.
Supplementary Movie 3. Migration of Dictyostelium cells under the cyclic stretching stimuli. (.mov)
The images where the substratum shrank in Movie 2 were extracted and accumulated sequentially. The movie is shown 450× faster than real time.

Using elastic sheets, it is difficult to exclude the Poisson's effect completely. In the case of our new device, when the sheet was stretched, 1/4 of perpendicular shrinkage took place, simultaneously. Cells showed random migration under the cyclic stretching stimuli of 10% stretching ratio and 10-s time cycle (Figure 3, A, B, and I). This indicates that cyclic stretching of <10% does not affect directionality of cell migration. In all experiments, the ratios of perpendicular shrinkage by Poisson's effect were <7.5% (Table 1). Thus, the perpendicular shrinkage in all experiments should not affect the directionality of cell migration. On the other hand, the speed of cell migration increased even when the ratio of cyclic stretching was 10% (Figure 3J). These results suggest that the perpendicular migration and increase in the migration speed in response to the cyclic stretching stimuli are mediated by different mechanisms.

The mechanical interaction between the cell and substratum may act as a primitive signaling cascade for determining polarity and migration direction because cells can migrate even if there are no additional environmental signals (such as a concentration gradient of a chemoattractant). It is generally believed that the mechanism of cell migration is based on actin polymerization at the front of the migrating cells, and actomyosin-dependent contraction at the rear (30). We proposed a model for cell migration in which myosin II may accumulate and exert an active force at the stretched region of the cell (31). The aspiration of a small part of the cell surface by a micropipette induced myosin II accumulation at the tip of the aspirated cell lobe, suggesting that myosin II may accumulate in response to mechanical stimulation (5). Our hypothesis of the mechanism of the migration perpendicular to the cyclic stretching is as follows: In response to the right-left cyclic stretching of the substratum, myosin II may accumulate right-left symmetrically. This may make the probabilities of the right and left migration equiprobable. A future topic of interest is determining whether the stretch stimuli generate polarized cell migration via polarized regulation of actin polymerization or actomyosin-dependent contraction. Further detailed observations using the new device described here will shed light on the relationship between the mechanosensing and molecular machinery involved in cell migration.

Acknowledgments

We thank Peter N. Devreotes (Johns Hopkins University, Baltimore, MD, USA) for the kind gift of the Dictyostelium cell line RI9. This study was partly supported by a Grant-in-Aid for Scientific Research on Priority Areas to SY from Japan's Ministry of Education, Culture, Sports, Science and Technology (MEXT). We are grateful for their support.

The authors declare no competing interests.

Correspondence
Address correspondence to Yoshiaki Iwadate, Department of Functional Molecular Biology, Graduate School of Medicine, Yamaguchi University, Yamaguchi 753-8512, Japan. Email: [email protected]

References
1.) Chien, S. 2008. Effects of disturbed flow on endothelial cells. Ann. Biomed. Eng. 36:554-562.

2.) Ricci, A.J., B. Kachar, J. Gale, and S.M. Van Netten. 2006. Mechano-electrical transduction: new insights into old ideas. J. Membr. Biol. 209:71-88.

3.) Mitchson, J.M., and M.M. Swann. 1954. The mechanical properties of the cell surface: I. The cell elastimeter. J. Exp. Biol. 31:31443-31460.

4.) Hochmuth, R.M. 2000. Micropipette aspiration of living cells. J. Biomech. 33:15-22.

5.) Merkel, R., R. Simson, D.A. Simson, M. Hohenadl, A. Boulbitch, E. Wallraff, and E. Sackmann. 2000. A micromechanic study of cell polarity and plasma membrane cell body coupling in Dictyostelium. Biophys. J. 79:707-719.

6.) Effler, J.C., Y. Kee, J.M. Berk, M.N. Tran, P.A. Iglesias, and D.N. Robinson. 2006. Mitosis-specific mechanosensing and contractile-protein redistribution control cell shape. Curr. Biol. 16:1962-1967.

7.) Wu, C.-C., Y.-S. Li, J.H. Haga, R. Kaunas, J.-J. Chiu, F.-C. Su, S. Usami, and S. Chien. 2007. Directional shear flow and Rho activation prevent the endothelial cell apoptosis induced by micropatterned anisotropic geometry. Proc. Natl. Acad. Sci. USA 104:1254-1259.

8.) Chang, S.-F., C.A. Chang, D.-Y. Lee, P.-L. Lee, Y.-M. Yeh, C.-R. Yeh, C.-K. Cheng, S. Chien, and J.-J. Chiu. 2008. Tumor cell cycle arrest induced by shear stress: roles of integrins and Smad. Proc. Natl. Acad. Sci. USA 105:3927-3932.

9.) Dalous, J., E. Burghardt, A. Muller-Taubenberger, F. Bruckert, G. Gerisch, and T. Bretschneider. 2008. Reversal of cell polarity and actin-myosin cytoskeleton reorganization under mechanical and chemical stimulation. Biophys. J. 94:1063-1074.

10.) Fass, J.N., and D.J. Odde. 2003. Tensile force-dependent neurite elicitation via anti-beta1 integrin antibody-coated magnetic beads. Biophys. J. 85:623-636 .

11.) Tanase, M., N. Biais, and M. Sheetz. 2007. Magnetic tweezers in cell biology. Methods Cell Biol. 83:473-493.

12.) Henon, S., G. Lenormand, A. Richert, and F. Gallet. 1999. A new determination of the shear modulus of the human erythrocyte membrane using optical tweezers. Biophys. J. 76:1145-1151.

13.) Mills, J.P., M. Diez-Silva, D.J. Quinn, M. Dao, M.J. Lang, K.S.W. Tan, C.T. Lim, G. Milon. 2007. Effect of plasmodial RESA protein on deformability of human red blood cells harboring Plasmodium falciparum. Proc. Natl. Acad. Sci. USA 104:9213-9217.

14.) Lim, C.T., E.H. Zhou, and S.T. Quek. 2006. Mechanical models for living cells. J. Biomech. 39:195-216.

15.) Giannone, G., and M.P. Sheetz. 2006. Substrate rigidity and force define form through tyrosine phosphatase and kinase pathways. Trends Cell Biol. 16:213-223.

16.) Vogel, V., and M. Sheetz. 2006. Local force and geometry sensing regulate cell functions. Nat. Rev. Mol. Cell Biol. 7:265-275.

17.) Naruse, K., T. Yamada, and M. Sokabe. 1998. Involvement of SA channels in orienting response of cultured endothelial cells to cyclic stretch. Am. J. Physiol. 274:H1532-H1538.

18.) Naruse, K., T. Yamada, X.R. Sai, M. Hamaguchi, and M. Sokabe. 1998. Pp125FAK is required for stretch dependent morphological response of endothelial cells. Oncogene 17:455-463.

19.) Birukov, K.G., J.R. Jacobson, A.A. Flores, S.Q. Ye, A.A. Birukova, A.D. Verin, and J.G.N. Garcia. 2003. Magnitude-dependent regulation of pulmonary endothelial cell barrier function by cyclic stretch. Am. J. Physiol. Lung Cell. Mol. Physiol. 285:L785-L797.

20.) Kaunas, R., P. Nguyen, S. Usami, and S. Chien. 2005. Cooperative effects of Rho and mechanical stretch on stress fiber organization. Proc. Natl. Acad. Sci. USA 102:15895-15900.

21.) Mark, J.E. 1999. Polymer Data Handbook. Oxford University Press, New York.

22.) Insall, R.H., R.D. Soede, P. Schaap, and P.N. Devreotes. 1994. Two cAMP receptors activate common signaling pathways in Dictyostelium. Mol. Biol. Cell 5:703-711.

23.) Li, L., S.F. Nørrelykke, and E.C. Cox. 2008. Persistent cell motion in the absence of external signals: A search strategy for eukaryotic cells. PLoS One 3:e2093.

24.) Lazopoulos, K.A., and D. Stamenovi. 2008. Durotaxis as an elastic stability phenomenon. J. Biomech. 41:1289-1294.

25.) Jiang, G., A.H. Huang, Y. Cai, M. Tanase, and M.P. Sheetz. 2006. Rigidity sensing at the leading edge through alphavbeta3 integrins and RPTPalpha. Biophys. J. 90:1804-1809.

26.) Lo, C.M., H.B. Wang, M. Dembo, and Y.L. Wang. 2000. Cell movement is guided by the rigidity of the substrate. Biophys. J. 79:144-152.

27.) Andrew, N., and R.H. Insall. 2007. Chemotaxis in shallow gradients is mediated independently of PtdIns 3-kinase by biased choices between random protrusions. Nat. Cell Biol. 9:193-200.

28.) Sato, M.J., H. Kuwayama, W.N. van Egmond, A.L.K. Takayama, H. Takagi, P.J.M. van Haastert, T. Yanagida, and M. Ueda. 2009. Switching direction in electric-signal-induced cell migration by cyclic guanosine monophosphate and phosphatidylinositol signaling. Proc. Natl. Acad. Sci. USA 106:6667-6672.

29.) Pullar, C.E., B.S. Baier, Y. Kariya, A.J. Russell, B.A. Horst, M.P. Marinkovich, and R.R. Isseroff. 2006. Beta4 integrin and epidermal growth factor coordinately regulate electric field-mediated directional migration via Rac1. Mol. Biol. Cell 17:4925-4935.

30.) Yumura, S., H. Mori, and Y. Fukui. 1984. Localization of actin and myosin for the study of ameboid movement in Dictyostelium using improved immunofluorescence. J. Cell Biol. 99:894-899.

31.) Iwadate, Y., and S. Yumura. 2008. Actin-based propulsive forces and myosin-II-based contractile forces in migrating Dictyostelium cells. J. Cell Sci. 121:1314-1324.

  1    2    3    4    5