Differential expression of platelet-endothelial cell adhesion molecule-1 (PECAM-1) in murine tissues.
OBJECTIVE
To characterize and compare the expression of PECAM-1 in unstimulated and tumor necrosis factor alpha-(TNF-alpha)-stimulated tissues of mice.


METHODS
Binding and non-binding monoclonal antibodies (mAb) were radiolabeled and injected into wild-type mice and mice deficient of P-selectin, CD18, or ICAM-1. The relative accumulation of binding mAb (PECAM-1 mAb) was determined in wild-type mice following a 25 micrograms/kg i.p. injection of TNF-alpha and in mutant mice under basal conditions.


RESULTS
Under unstimulated conditions, PECAM-1 was significantly expressed in all tissues examined, with no changes occurring after TNF-alpha stimulation. An equivalence of PECAM-1 expression was observed in unstimulated tissues among wild-type mice and mice that are genetically deficient in either CD18, ICAM-1, or P-selectin. The level of PECAM-1 expression in different vascular beds was highly correlated to published values of endothelial surface area. Normalization of previously published values of ICAM-1, VCAM-1, E- and P-selectin expression relative to PECAM-1 expression in the same tissues revealed a diminished organ-to-organ variability in expression of the different adhesion molecules. Estimates of adhesion molecule expression in lung and brain were most profoundly affected by normalization to PECAM-1 expression.


CONCLUSIONS
These findings support the use of PECAM-1 expression in regional vascular beds as an indicator of endothelial cell surface area.
Eppihimer
M J
MJ
Department of Molecular and Cellular Physiology, Louisiana State University Medical Center, Shreveport 71130-3932, USA.
Russell
J
J
Langley
R
R
Vallien
G
G
Anderson
D C
DC
Granger
D N
DN
D000818:Animals; D000911:Antibodies, Monoclonal; D018821:CD18 Antigens / Q000235:genetics / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008833:Microcirculation / Q000378:metabolism*; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D014018:Tissue Distribution; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D018821:CD18 Antigens; D019007:P-Selectin; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1