Figure 3
Endothelial S1P 5 activation decreases monocyte transmigration. FTY720P (10−6 M in DMSO; a) and a S1P5 agonist (10−6 M in DMSO; b) were added to confluent monolayers of hCMEC/D3 cells for 24 hours. Monocyte migration was assayed by time lapse microscopy, FTY720P treatment of the brain ECs reduced monocyte migration to 55.3% ± 7.42 (n = 3) compared to control (106.0% ± 6.14 n = 3; a) and treatment with the selective S1P5 agonist reduced monocyte migration to 75.9% ± 0.68 n = 3; b). Both FTY720P and S1P5 agonist treated cells show reduced VCAM-1 expression (control: 100.0% ± 17.0; S1P5 agonist 64.8% ± 8.9, n = 3; c) and increased VE-cadherin expression (control: 100.0% ± 8.5; S1P5 agonist: 126.3% ± 2. 6, n = 3; d). Values represent the mean ± SEM of three individual experiments each performed in triplicate with controls set at 100%. Statistical significance (t-test) is indicated with asterisks: *P < 0.05 **P < 0.002 and ***P < 0.001.