Podocalyxin enhances the adherence of cells to platelets.
Podocalyxin (PODXL) is a mucin protein of the CD34 family expressed in kidney glomerular podocytes, vascular endothelium, progenitor bone marrow and tumor cells. It is assumed that PODXL plays an anti-adherent role in kidney podocytes. CHO cells stably expressing human PODXL (CHO-PODXL) or human tumor cells (Tera-1) inherently expressing PODXL showed increased adherence to platelets. The adherence of cells was inhibited (70%) by blockers of platelet P-selectin, prevented by the soluble ectodomain of human PODXL (PODXL-Delta) or by the arginine-glycine-aspartate (RGDS) peptide and partially impeded by inhibition of integrin alphaVbeta3/alphaVbeta5, suggesting a coordinated action of P-selectin and integrins. Colocalization of platelet P-selectin and PODXL expressed on CHO cells was demonstrated by confocal immunofluorescence. No adherence to platelets was observed when PODXL was expressed in glycomutant CHO cells deficient in sialic acid.
Larrucea
S
S
Department of Physiopathology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain.
Butta
N
N
Rodriguez
R B
RB
Alonso-Martin
S
S
Arias-Salgado
E G
EG
Ayuso
M S
MS
Parrilla
R
R
D000818:Animals; D001483:Base Sequence; D001792:Blood Platelets / Q000502:physiology*; D016466:CHO Cells; D002448:Cell Adhesion / Q000502:physiology*; D006224:Cricetinae; D003412:Cricetulus; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D006031:Glycosylation; D006801:Humans; D016023:Integrins / Q000502:physiology; D051379:Mice; D009154:Mutation; D019007:P-Selectin / Q000502:physiology; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012795:Sialoglycoproteins / Q000235:genetics / Q000502:physiology*; D014162:Transfection
D017931:DNA Primers; D018076:DNA, Complementary; D016023:Integrins; D019007:P-Selectin; D011994:Recombinant Proteins; D012795:Sialoglycoproteins; C001643:podocalyxin