Cationic antimicrobial protein of Mr 37 kDa: a multifunctional inflammatory protein.
OBJECTIVE
To investigate the role of cationic antimicrobial protein of Mr 37 kDa (CAP37) a neutrophil-derived inflammatory mediator on endothelial cell function.


METHODS
Endothelial cells used in this study were obtained from human lung microvessels and rat aorta. The latter was a kind gift of Dr. Paula Grammas. The mono-mac 6 cell line used in this study was the generous gift of Dr. H.W. Loms Ziegler-Heitbrock.


METHODS
Endothelial cell proteins kinase C activity was determined by measuring calcium- and phospholipid-dependent phosphorylation of histone. Endothelial cell migration was determined using Costar Transwell apparatus. Cell surface expression of adhesion molecules, ICAM-1 and PECAM-1 was determined using flow cytometry. RT-PCR was used to amplify the CAP37 from endothelial cells treated with LPS.


RESULTS
We demonstrated that CAP37 which was originally identified as having potent antimicrobial activity and chemotactic activity for monocytes was capable of modulating endothelial cell functions. CAP37 activated endothelial cell protein kinase C in a dose- and time-dependent fashion. Importantly CAP37 increased the adhesive properties of the endothelium for monocytes. CAP37 upregulated the well known adhesion molecules, ICAM-1 and PECAM-1 in a dose- and time-dependent manner. In addition, CAP37 promoted endothelial cell migration. Further investigations indicated that CAP37 was induced in endothelial cells in response to pro-inflammatory cytokines such as tumor necrosis factor-alpha and interleukin-1 alpha as well as inflammatory mediators such as lipopolysaccharide. Unstimulated endothelial cells did not constitutively express CAP37. The cDNA sequence of endothelial CAP37 was determined and found to be highly homologous to the sequence obtained for neutrophil-derived CAP37.


CONCLUSIONS
Our studies strongly suggest that CAP37 plays a pivotal role in monocyte-endothelial interactions and the transmigration of monocytes from the vasculature into extravascular tissues.
Pereira
H A
HA
Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma 73190, USA. Anne-Pereira@ouhsc.edu
D000818:Animals; D023181:Antimicrobial Cationic Peptides; D001483:Base Sequence; D001798:Blood Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D018076:DNA, Complementary / Q000737:chemistry; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D011493:Protein Kinase C / Q000378:metabolism
C062991:AZU1 protein, human; D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D002352:Carrier Proteins; D018076:DNA, Complementary; D011493:Protein Kinase C