Interleukin-1β Enhances Umbilical Cord Mesenchymal Stem Cell Adhesion Ability on Human Umbilical Vein Endothelial Cells via LFA-1/ICAM-1 Interaction

Figure 4

p38 MAPK signaling pathway is involved in IL-1β-mediated LFA-1 expression in MSCs and MSC adhesion to HUVECs. (a) Immunocytochemistry staining for LFA-1 (green) and DAPI (blue) in MSCs. Cells were treated with p38 MAPK (SB 203580, 5 μM), AKT (GSK690693, 20 μM), ERK1/2 (U0126 20 μM), and JNK (SP600125 20 nM) inhibitor and combined with IL-1β for 30 minutes (scale bar: 50 μm). (b) Western blot results of the p38 MAPK and phosphorylated p38 MAPK from the lysates of cells pretreated with IL-1β at 0, 1, 3, 5, 10, and 20 minutes. (c) Western blot results of the LFA-1 (129 kDa) expression in membrane fractions of MSCs treated with IL-1β and SB 203580 (SB) or cotreated with both IL-1β and SB. (d) Quantitative graphs of the Western blot results of LFA-1 expression of (c) (, ). (e) Representative image of MSC adhesion on HUVECs. MSCs were treated with IL-1β and inhibitor SB 203580 adhesion to IL-1β-activated HUVECs or nonactivated HUVECs. MSCs labelled with calcein AM (5 μM) (green), HUVECs, and MSC cell nuclei were stained with Hoechst 33258 (blue) (scale bar: 50 μm). (f) Quantitative graphs of the cell adhesion assay results of MSCs treated with IL-1β and MAPK inhibitor SB 203580 adhesion to nonactivated HUVECs (black bars) or IL-1β-activated HUVECs (gray bars). Values were the cell number fold change relative to the control group. Data represent (, , , and ) (N.S.: nonsignificance).

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