Leukocyte migration after intradermal injection of CXCL1 in sdc-3 null and wild-type mice and altered distribution of E-selectin. (A) Mice were injected intradermally with recombinant murine CXCL1 (3 μg/site in PBS) or PBS as control. After four hours the animals were sacrificed and skin biopsies were processed for light microscopy. Haematoxylin and eosin staining of skin sections show neutrophil recruitment into the dermis in sdc-3−/− (mid panel) and sdc-3+/+ (right panel) mice. The left micrograph shows skin from an sdc-3−/−mouse following PBS administration. Scale bar 50 μm. (B) Using the same samples as in (A) lysates were prepared from skin biopsies and myeloperoxidase (MPO) activity measured as a marker for the presence of neutrophils. Increased MPO activity is observed in sdc-3−/−compared to sdc-3+/+skin tissue. For sdc-3−/−mice n = 9 with CXCL1 and with PBS, and for sdc-3+/+mice n = 10 with CXCL1 and with PBS. Data are means ± SEM. *P <0.03 compared with CXCL1 injected sdc-3+/+mice. #P <0.005 compared to respective PBS control. (C and D) Sdc-3 staining of endothelial cells is shown in a dermal venule from a wild-type mouse. (E and F) E-selectin shows a luminal distribution in the endothelial cells of the dermis after PBS (E) and CXCL1 (F) administration, this section is from a sdc-3−/−mouse. Scale bar 50 μm for E-selectin and 25 μm for sdc-3 micrographs. (G) Quantification of the number of blood vessels with a luminal E-selectin distribution in the dermis of sdc-3+/+ (n = 8) compared to sdc-3−/− (n = 9) mice. Data are mean ± SEM, **P <0.008 compared to sdc-3 wild-type mice. CXCL1, chemokine C-X-C ligand 1; PBS, phosphate-buffered saline.