Figure 1.
Lateral migration set-up of HaCaT or HF cells cultured on collagen I-coated PDMS membrane in a tensile device.
(A) An in-house developed tensile device by applying mechanical stretch, via the PDMS membrane, to the cells (upper panel). Also plotted was the tensile strain profile of PDMS membrane at a pre-set 20% strain along tensile direction (x-axis) (lower panel). (B) Schematic of monocultured (upper panel) or cocultured (lower panel) HaCaT or HF cells on the stretched membrane where the cells tend to migrate in two directions with a distance L or L’ at a given time point. Arrows indicate the migration direction of the cells when they are monocultured (to leftward or rightward) or cocultured (to outward or inward). (C, D) Typical images of cocultured HaCaT cells at t = 0 (C) and 6 day (D) with the leading edge indicated as white dashed lines (Bar = 500 µm) with the inserts illustrating the magnified images (Bar = 100 µm). The white strip in (D) was used to disconnect the oversized image.
Figure 2.
Lateral migration of HaCaT cells on collagen I-coated PDMS membrane in the absence or presence of HF cells and mechanical stretch.
(A, B) Time course of normalized instantaneous or accumulative distance of monocultured (M/N) (A) or cocultured (C/N) (B) HaCaT cells in the absence of mechanical stretch. (C, D) Time course of normalized instantaneous or accumulative distance of monocultured (M/S) (C) or cocultured (C/S) (D) HaCaT cells in the presence of mechanical stretch. Data were collected from at least triplets and presented as the mean±standard deviation (SD) of migration distance and then normalized by the initial width at t = 0 day. P value indicates the level of statistical significance of difference in normalized distances between leftward and rightward migration for M/N and M/S or inward and outward migration for C/N and C/S. Arrows indicate the different scales of the double y-axes for normalized instantaneous and accumulative distances.
Figure 3.
Lateral migration of HF cells on collagen I-coated PDMS membrane in the absence or presence of HaCaT cells and mechanical stretch.
(A, B) Time course of normalized instantaneous or accumulative distance of monocultured (M/N) (A) or cocultured (C/N) (B) HF cells in the absence of mechanical stretch. (C, D) Time course of normalized instantaneous or accumulative distance of monocultured (M/S) (C) or cocultured (C/S) (D) HF cells in the presence of mechanical stretch. Data were collected and presented in the same way as Fig. 2.
Figure 4.
Transmembrane migration set-up of HaCaT or HF cells using a modified transwell assay.
Plotted was up-to-down (A) or down-to-up (B) transmigration of monoclutured or cocultured HaCaT or HF cells in the absence or presence of mechanical stretch. Integration of the mechanical stretch assay with the modified transwell assay was also illustrated (C) and the detailed protocols were referred in Fig. S4.
Figure 5.
Transmigration of HaCaT cells on collagen I-coated transwell chamber.
(A, B) Up-to-down (A) or down-to-up (B) transmigration of monoclutured or cocultured HaCaT cells in the absence of mechanical stretch. (C, D) Up-to-down or down-to-up transmigration of cocultured HaCaT cells in the absence (C) or presence (D) of mechanical stretch. Data are presented as the fraction of transmigrated HaCaT cells at t = 36, 48 h normalized to that at t = 24 h in respective cases.
Figure 6.
Transmigration of HF cells on collagen I-coated transwell chamber.
Up-to-down (A) or down-to-up (B) transmigration of monoclutured or cocultured HF cells in the absence or presence of mechanical stretch. Data are presented as the fraction of transmigrated HaCaT cells at t = 36, 48 h normalized to that at t = 24 h in respective cases.
Figure 7.
Comparison of content of EGF secretion in the conditional medium using 2D (A) or 3D (B) assay.
Data were collected from at least triplets and presented as the average optical intensity at OD 450
Figure 8.
Inhibition of EGF in lateral (A) or transmembrane (B) migration of HaCaT cells.
Data were presented as the mean ± SD of cell migration distance normalized by initial width of HaCaT cells at t = 0 day (A) or of fraction of transmigrated HaCaT cells at t = 36, 48 h normalized to that at t = 24 h in respective cases (B). Data at t = 24 h were not presented for the sake of clarity.
Figure 9.
Inhibition of TGF-α (A) or TGF-β1 (B) in transmigration of HaCaT cells.
Data were presented as the mean ± SD of fraction of transmigrated HaCaT cells at t = 36, 48 h normalized to that at t = 24 h in respective cases. Data at t = 24 h were not presented for the sake of clarity.