Cell migration through small gaps

Abstract

Cell motility is a fundamental process associated with many phenomena in nature, such as immune response, wound healing, and cancer metastasis. In these processes, cells must squeeze through cell layers, and we characterize this ability to actively produce forces and simultaneously adapt their shapes. We have measured forward forces up to 15 nN that a migrating keratocyte was able to generate, in order to adjust its shape and successfully force its way under and past an obstacle. We also observed that 34 nN was capable of stalling the cell's forward motion. Furthermore, we measured that under compression stresses up to 1,165 pN/micro m2 (1,165 Pa), cell morphology, and velocity remained unchanged. Additionally, we found that keratocytes were able to compress themselves up to 80% vertically in order to squeeze through a gap as small as 500 nm.

Mathematical Modeling of Melanoma Cell Migration with an Elastic Continuum Model for the Evaluation of the Influence of Tumor Necrosis Factor-Alpha on Migration

“…Therefore, considering that melanoma cells migrating in the assay under the influence of TNF-show the same elasticity modulus of the melanoma cells migrating in control situation, the cell layer would have force resulting from lamellipod formation of approximately 5.72 nN and adhesion constant of approximately 0.2 h nN/ m 2 . Based on the literature, values of protrusive force have measures that vary from 0.5 nN to 85 nN, depending on the method used for measuring and the place of the cell where the force was measured on [29][30][31]. Furthermore, the increased force observed from the control to the TNF-situation is also in accordance with expected.…”

Probing cellular microenvironments and tissue remodeling by atomic force microscopy

“…6b). To study this, a micron-sized polystyrene bead was glued to a cantilever and positioned in front of a locomoting keratocyte, a popular in vitro model of a quickly moving cell [17]. In agreement with the aforementioned experiment, the cell was found to exert pushing pressure against the cantilever of the order of 1 kPa.…”

Asymmetry between pushing and pulling for crawling cells

“…This gives for the dimensional velocity of the unloaded cell (χ/ √ ξη)V * = 0.37×10 −7 m·s −1 and for its dimensional length √ ηξL * ∞ = 0.3 × 10 −7 m. This length scale is of the right order of magnitude while the velocity scale is at least an order of magnitude smaller than the values recorded for keratocytes and fibroblasts [18,48]. In the case of pure pushing = −1, we can use the area S = 10 −12 m 2 to obtain the dimensional value of the stall force χSQ * = 1nN which is realistic [16][17][18][19]. Based on these estimates we conclude that negative motility may be expected in the interval of pulling force values 1 − 1.7nN and this prediction can be tested experimentally.…”

“…The equation (16), which is nonlinear in contrast to what we have had in the minimal model, must be again supplemented by two mechanical boundary conditions, σ(0) = q − and σ(L ∞ ) = q + , and two kinematic boundary conditions,…”

“…An inherent functional disparity between protrusion-contraction components of the motility mechanism suggests a fundamental difference in the structure of the force-velocity relations associated with pushing and pulling. In experimental studies pushing and pulling are often difficult to distinguish and most of the measured force-velocity data are attributed to pushing [16][17][18][19].…”