Directed cell movement and cluster formation : 
physical principles

Gruler, Hans; Boisfleury-Chevance, A de

doi:10.1051/jp1:1994186

Cited by 16 publications

(9 citation statements)

References 4 publications

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“…At high enough cell density, the cells form a cluster where each cell tries to move towards the center of the cluster [7]. (b) A similar process is observed with migrating white blood cells [3]. If human leukocytes (granulocytes) are expose to blood plasma they then migrate as single amoeboid cells on a surface as shown in Figure 1a.…”

Section: Introductionmentioning

confidence: 96%

“…To generate a liquid crystal one must use anisotropic objects, like elongated molecules. Several ways are known to achieve this: with small molecules; with long helical rods that either occur in nature or can be made artificially; with polymers; with more complex structure units like the capside of a virus [2], that is an associated structure of molecules and ions; likewise, with even more complex structure units, like amoeboid cells which are complex structures far from thermodynamic equilibrium and act as machines [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

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Elastic properties of nematoid arrangements formed by amoeboid cells

et al. 2000

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In culture migrating and interacting amoeboid cells can form nematoid arrangements in analogy to a nematic liquid crystal phase. A nematoid arrangement is formed if the interaction has an apolar symmetry. Different cell types like human melanocytes (= pigment cells of the skin), human fibroblasts (= connective tissue cells), human osteoblasts (= bone cells), human adipocytes (= fat cells) etc., form a nematoid structure. Our hypothesis is that elastic properties of these nematoid structures can be described in analogy to that of classical nematic liquid crystals. The orientational elastic energy is derived and the orientational defects (disclination) of nematoid arrangements are investigated. The existence of halfnumbered disclinations shows that the nematoid structure has an apolar symmetry. The density-and order parameter dependence of the orientational elastic constants and their absolute values are estimated. From the defect structure, one finds that the splay elastic constant is smaller than the bend elastic constant (melanocytes). The core of a disclination is either a cell free space or occupied by non oriented cells (isotropic state), by a cell with a different symmetry, or by another cell type.

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Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Elastic properties of nematoid arrangements formed by amoeboid cells

et al. 2000

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“…The strong cell-cell attraction creates droplets of cells where each cell tries to reach the center of the droplet. This ordered structure is verified for human granulocytes exposed to low calcium concentration [12] and for slime mould cells exposed to low nutrition concentration [26].…”

Section: Predicted Liquid Crystal Analoguesmentioning

confidence: 84%

“…The stability of such self-organized structures cannot be derived by searching the minimum of a thermodynamic potential (thermodynamic equilibrium) because the involved cells are energy consuming machines which work far from thermodynamic equilibrium. The following new concept is used [8,[11][12][13]:…”

Section: Introductionmentioning

confidence: 99%

“…It has been recently shown that migrating and interacting amoeboid cells like granulocytes (white blood cell) [12], melanocytes (pigment cell of the skin) [13], etc., can form nematic liquid crystal state analogues. The topic of this paper is to show the analogy between the orderdisorder phase transition (elongated molecules at thermal equilibrium) and the order-disorder state transition (migrating and interacting machines far from thermal equilibrium).…”

Section: Introductionmentioning

confidence: 99%

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Nematic order-disorder state transition in a liquid crystal analogue formed by oriented and migrating amoeboid cells

Kemkemer

Teichgräber

Schrank-Kaufmann

et al. 2000

The European Physical Journal E

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In cell culture, liquid crystal analogues are formed by elongated, migrating, and interacting amoeboid cells. An apolar nematic liquid crystal analogue is formed by different cell types like human melanocytes (=pigment cells of the skin), human fibroblasts (=connective tissue cells), human osteoblasts (=bone cells), human adipocytes (=fat cells), etc. The nematic analogue is quite well described by i) a stochastic machine equation responsible for cell orientation and ii) a self-organized extracellular guiding signal, E 2, which is proportional to the orientational order parameter as well as to the cell density. The investigations were mainly made with melanocytes. The transition to an isotropic state analogue can be accomplished either by changing the strength of interaction (e.g. variation of the cell density) or by influencing the cellular machinery by an externally applied signal: i) An isotropic gaseous state analogue is observed at low cell density (ρ < 110 melanocytes/mm 2 ) and a nematic liquid crystal state analogue at higher cell density. ii) The nematic state analogue disappears if the bipolar shaped melanocytes are forced to become a star-like shape (induced by colchicine or staurosporine). The analogy between nematic liquid crystal state analogue formed by elongated, migrating and interacting cells and the nematic liquid crystal phase formed by interacting elongated molecules is discussed.

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