title: Syndecan-1 in the mouse parietal peritoneum microcirculation in inflammation.
abstract: BACKGROUND
  The heparan sulfate proteoglycan syndecan-1 (CD138) was shown to regulate inflammatory responses by binding chemokines and cytokines and interacting with adhesion molecules, thereby modulating leukocyte trafficking to tissues. The objectives of this study were to examine the expression of syndecan-1 and its role in leukocyte recruitment and chemokine presentation in the microcirculation underlying the parietal peritoneum.
  
  
  METHODS
  Wild-type BALB/c and syndecan-1 null mice were stimulated with an intraperitoneal injection of Staphylococcus aureus LTA, Escherichia coli LPS or TNFα and the microcirculation of the parietal peritoneum was examined by intravital microscopy after 4 hours. Fluorescence confocal microscopy was used to examine syndecan-1 expression in the peritoneal microcirculation using fluorescent antibodies. Blocking antibodies to adhesion molecules were used to examine the role of these molecules in leukocyte-endothelial cell interactions in response to LTA. To determine whether syndecan-1 co-localizes with chemokines in vivo, fluorescent antibodies to syndecan-1 were co-injected intravenously with anti-MIP-2 (CXCL2), anti-KC (CXCL1) or anti-MCP-1 (CCL2).
  
  
  CONCLUSIONS
  Syndecan-1 was localized to the subendothelial region of peritoneal venules and the mesothelial layer. Leukocyte rolling was significantly decreased with LPS treatment while LTA and TNFα significantly increased leukocyte adhesion compared with saline control. Leukocyte-endothelial cell interactions were not different in syndecan-1 null mice. Antibody blockade of β2 integrin (CD18), ICAM-1 (CD54) and VCAM-1 (CD106) did not decrease leukocyte adhesion in response to LTA challenge while blockade of P-selectin (CD62P) abrogated leukocyte rolling. Lastly, MIP-2 expression in the peritoneal venules was not dependent on syndecan-1 in vivo. Our data suggest that syndecan-1 is expressed in the parietal peritoneum microvasculature but does not regulate leukocyte recruitment and is not necessary for the presentation of the chemokine MIP-2 in this tissue.
authors.affiliation: Medical Sciences Graduate Program, McMaster University, Hamilton, ON, Canada.
authors.forename: Paulina M
authors.initials: PM
authors.lastname: Kowalewska
authors.affiliation: Thrombosis and Atherosclerosis Research Institute and the Department of Medicine, McMaster University, Hamilton, ON, Canada.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Patrick
authors.affiliation: Thrombosis and Atherosclerosis Research Institute and the Department of Medicine, McMaster University, Hamilton, ON, Canada.
authors.forename: Alison E
authors.initials: AE
authors.lastname: Fox-Robichaud
mesh_terms: D000818:Animals; D000906:Antibodies / Q000008:administration & dosage; D018821:CD18 Antigens / Q000235:genetics / Q000276:immunology; D002465:Cell Movement; D018932:Chemokine CCL2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000276:immunology; D054360:Chemokine CXCL1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000276:immunology; D054426:Chemokine CXCL2 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000276:immunology; D042783:Endothelial Cells / Q000276:immunology / Q000473:pathology; D015870:Gene Expression; D007249:Inflammation / Q000139:chemically induced / Q000235:genetics / Q000276:immunology / Q000473:pathology; D007274:Injections, Intraperitoneal; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000276:immunology; D007962:Leukocytes / Q000276:immunology / Q000473:pathology; D008070:Lipopolysaccharides / Q000008:administration & dosage; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D019007:P-Selectin / Q000037:antagonists & inhibitors / Q000235:genetics / Q000276:immunology; D010537:Peritoneum / Q000098:blood supply* / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D053668:Syndecan-1 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000276:immunology
chemical_list: D000906:Antibodies; D018821:CD18 Antigens; C491768:Ccl2 protein, mouse; D018932:Chemokine CCL2; D054360:Chemokine CXCL1; D054426:Chemokine CXCL2; C475895:Cxcl1 protein, mouse; C404915:Cxcl2 protein, mouse; D008070:Lipopolysaccharides; D019007:P-Selectin; C508242:Sdc1 protein, mouse; D053668:Syndecan-1; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1