Figure 4
Growth of MSCs is reversible by interchanging the culture conditions. (a) To determine if effects of supplements are reversible, we have interchanged culture media from FCS (2 days) to HPL (2 days) and then back to FCS (2 days) (n = 4). Exemplary phase contrast images are provided. (b) Aspect ratios at day 2 demonstrate that HPL-MSCs are more elongated than FCS-MSCs (****p < 0.0001). (c) Aspect ratios at day 4 demonstrate that interchanging to HPL-medium for only two days already results in significant elongation of the cells (****p < 0.0001). (d) This change in morphology is again reversible by again changing for two days to FCS culture medium (day 6; ****p < 0.0001). (e) Proliferation can be transiently accelerated by interchanging to HPL culture medium. (f) Immunofluorescence analysis of the actin cytoskeleton (green) and the focal-adhesion associated protein vinculin (red). Representative images at day 4 (2 days interchange to HPL medium; nucleus counterstained with DAPI in blue). (g) The number of focal adhesions, (h) mean area of focal adhesions per cell, and (i) mean aspect ratio of the focal adhesions were quantified at day 4. FCS-MSCs have more elongated focal adhesions than HPL-MSCs, and this is reversible by interchanging culture media for two days (**p < 0.01; ****p < 0.0001; ns = not significant).
