title: Rapidly self-renewing human multipotent marrow stromal cells (hMSC) express sialyl Lewis X and actively adhere to arterial endothelium in a chick embryo model system.
abstract: BACKGROUND
  There have been conflicting observations regarding the receptors utilized by human multipotent mesenchymal bone marrow stromal cells (hMSC) to adhere to endothelial cells (EC). To address the discrepancies, we performed experiments with cells prepared with a standardized, low-density protocol preserving a sub-population of small cells that are rapidly self-renewing.
  
  
  METHODS
  Sialyl Lewis X (SLeX) and α4 integrin expression were determined by flow cytometry. Fucosyltransferase expression was determined by quantitative realtime RT-PCR. Cell adhesion assays were carried out with a panel of endothelial cells from arteries, veins and the microvasculature in vitro. In vivo experiments were performed to determine single cell interactions in the chick embryo chorioallantoic membrane (CAM). The CAM is a well-characterized respiratory organ allowing for time-lapse image acquisition of large numbers of cells treated with blocking antibodies against adhesion molecules expressed on hMSC.
  
  
  RESULTS
  hMSC expressed α4 integrin, SLeX and fucosyltransferase 4 and adhered to human EC from arteries, veins and the microvasculature under static conditions in vitro. In vivo, hMSC rolled on and adhered to arterioles in the chick embryo CAM, whereas control melanoma cells embolized. Inhibition of α4 integrin and/or SLeX with blocking antibodies reduced rolling and adhesion in arterioles and increased embolism of hMSC.
  
  
  CONCLUSIONS
  The results demonstrated that rapidly self-renewing hMSC were retained in the CAM because they rolled on and adhered to respiratory arteriolar EC in an α4 integrin- and SLeX-dependent manner. It is therefore important to select cells based on their cell adhesion receptor profile as well as size depending on the intended target of the cell and the injection route.
authors.affiliation: Xavier University of Louisiana, Biology Department, New Orleans, Louisiana, United States of America; Center for Stem Cell Research and Regenerative Medicine, Tulane University School of Medicine, New Orleans, Louisiana, United States of America; Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America.
authors.forename: Harris E
authors.initials: HE
authors.lastname: McFerrin
authors.affiliation: Program in Regenerative Medicine, University of Texas Medical School at Houston, Houston, Texas, United States of America.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Olson
authors.affiliation: Stanford Department of Bioengineering, Stanford University, Stanford, California, United States of America.
authors.forename: Miriam V
authors.initials: MV
authors.lastname: Gutschow
authors.affiliation: Center for Stem Cell Research and Regenerative Medicine, Tulane University School of Medicine, New Orleans, Louisiana, United States of America.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Semon
authors.affiliation: Center for Stem Cell Research and Regenerative Medicine, Tulane University School of Medicine, New Orleans, Louisiana, United States of America; Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America.
authors.forename: Deborah E
authors.initials: DE
authors.lastname: Sullivan
authors.affiliation: Texas A & M Health Science Center College of Medicine Institute for Regenerative Medicine at Scott & White, Temple, Texas, United States of America.
authors.forename: Darwin J
authors.initials: DJ
authors.lastname: Prockop
mesh_terms: D000818:Animals; D001158:Arteries / Q000378:metabolism*; D002450:Cell Communication; D045744:Cell Line, Tumor; D002642:Chick Embryo; D042783:Endothelial Cells / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D039441:Integrin alpha4 / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D051379:Mice; D009844:Oligosaccharides / Q000378:metabolism*; D000080506:Sialyl Lewis X Antigen
chemical_list: D009844:Oligosaccharides; D000080506:Sialyl Lewis X Antigen; D039441:Integrin alpha4