Figure 1: Leukocyte rolling is reduced in S1P3−/− mice and after S1P3 blockade, respectively, and is enhanced by S1P administration.
From: Sphingosine-1-phosphate receptor 3 promotes leukocyte rolling by mobilizing endothelial P-selectin
Leukocyte rolling was quantified in postcapillary venules of the cremaster muscle of (a) S1P3−/− mice (n=5) and C57Bl6 controls (n=6). Rolling was abolished by systemic injection of a P-selectin-blocking antibody in both groups. Middle: representative snap shot images of rolling leukocytes (arrows) are shown. Right: representative whole-mount immunohistochemistry for P-Selectin after in vivo injection of an anti-P-selectin antibody (left: no staining in uninjured cremaster, right: luminal P-selectin staining in the contralateral exteriorized cremaster). Scale bar, 40 μm. (b) Unaltered rolling of S1P3−/− leukocytes on immobilized P-selectin. Microflow chambers were coated with recombinant murine P-selectin and perfused with arterial blood diverted from the carotid artery of C57Bl6 and S1P3−/− mice (n=3 each) for the indicated times. The number of rolling cells was quantified per field of view (FOV). (c) Rolling in C57Bl6 mice with (n=4) and without (n=5) the S1P3 inhibitor TY-52156 (1.25 mg kg−1 intraperitoneally (i.p.) 30 min before experiment). (d) Rolling in C57Bl6 mice at baseline and immediately after S1P injection into the carotid artery (30 μg kg−1, n=5). Quantitative data are presented as mean±s.e.m. Significance was established using a Wilcoxon rank sum test or a paired two-tailed Student’s t-test. In all experiments: *P<0.05; **P<0.01; ***P<0.001.
