Figure 4. Chemerin stimulates transendothelial migration of MSCs and requires MMP-2.

A, Representative fields from MSC transendothelial migration experiments showing migration of PKH67-labelled MSCs (left). CCX832 (1 µM) inhibited chemerin- (center) and CAM-CM stimulated MSC transendothelial migration but CCX826 (1 µM) had no effect (right). B, Chemerin, and IGF-II used as a positive control, promptly (30 min) stimulated proMMP2 abundance in media as detected by Western blot but had no effect on cellular proMMP2 abundance (left); chemerin significantly increased MMP-2 enzyme activity in MSC media detected by the selective substrate MCA-Pro-Leu-Ala-Nva-Dpa-Ala-Arg-NH₂ (right). C, Human recombinant MMP-2 (80 ng/ml) stimulated transendothelial migration and there was dose-dependent inhibition by an MMP-2 selective inhibitor (MMP-2 inhibitor I) (left). The MMP-2 inhibitor (60 µM) significantly inhibited chemerin-stimulated MSC transendothelial migration (centre). Horizontal arrows, p<0.05, t- test (n = 3).