Auto-Reverse Nuclear Migration in Bipolar Mammalian Cells on Micropatterned Surfaces


B. Szabó 1, Zs. Környei 2, J. Zách 3, D. Selmeczi 3, G. Csúcs 4, A. Czirók 3, and T. Vicsek 1,3
 

1 Research Group for Biological Physics, HAS, Budapest, Hungary
2 Institute of Experimental Medicine, Budapest, Hungary
3 Department of Biological Physics, Eötvös University, Budapest, Hungary
4 Laboratory for Biomechanics, ETH, Zürich, Switzerland

A novel assay based on micropatterning and time-lapse microscopy has been developed for the study of nuclear migration dynamics in cultured mammalian cells. When cultured on 10-20-µm wide adhesive stripes, the motility of C6 glioma and primary mouse fibroblast cells is diminished. Nevertheless, nuclei perform an unexpected auto-reverse motion: when a migrating nucleus approaches the leading edge, it decelerates, changes the direction of motion, and accelerates to move toward the other end of the elongated cell. During this process, cells show signs of polarization closely following the direction of nuclear movement. The observed nuclear movement requires a functioning microtubular system, as revealed by experiments disrupting the main cytoskeletal components with specific drugs. On the basis of our results, we argue that auto-reverse nuclear migration is due to forces determined by the interplay of microtubule dynamics and the changing position of the microtubule organizing center as the nucleus reaches the leading edge. Our assay recapitulates specific features of nuclear migration (cell polarization, oscillatory nuclear movement), while it allows the systematic study of a large number of individual cells. In particular, our experiments yielded the first direct evidence of reversive nuclear motion in mammalian cells, induced by attachment constraints. Cell Motil. Cytoskeleton 59:38 49, 2004.

Key words: microtubule dynamics; centrosome; cell polarization; interkinetic nuclear migration; ventricular zone

Supplemental movies

Video 1 (mov, mpg) displays the motility of C6 cells on the surface of 20-µm-wide Alexa488-labeled fibronectin-fibrinogen stripes.
Video 2 (mov, mpg) shows the reversive nuclear motion in a single C6 cell on a similar stripe. Frame size: 270x60  µm2.
Video 3 (mov, mpg)) (frame size: 400x115 µm2), 4 (mov, mpg) (frame size: 250x50 µm2), and 5 (mov, mpg) (frame size: 630x480 µm2) show the effect of 30 nM taxol (administered at 16 h), 20 nM vinblastine (administered at 9 h), and 500 nM cytochalasin D (administered at 12 h), respectively, on auto-reverse nuclear migration in C6 cells cultured on 20-µm-wide stripes.

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