Mast cell tryptase in mast cell granules enhances MCP-1 and interleukin-8 production in human endothelial cells.
OBJECTIVE
Recent studies have highlighted the pathogenetic importance of chronic inflammation in cardiovascular disorders such as congestive heart failure and atherosclerosis. Mast cells release a wide variety of immune mediators that may initiate inflammatory responses, whereas endothelial cells (ECs) play a prominent role in the pathogenesis of cardiovascular diseases by secreting cytokines. The purpose of this study was to clarify the role of mast cells as an activator of ECs.


RESULTS
ECs harvested from human umbilical cord veins were stimulated with mast cell granules (MCGs) prepared from sonicated human leukemic mast cells. The supernatants and total RNA from cells were collected. Levels of interleukin (IL)-1beta, tumor necrosis factor-alpha, and granulocyte colony-stimulating factor remained unchanged up to 24 hours. In contrast, levels of monocyte chemoattractant protein-1 (MCP-1) and IL-8 increased significantly within 6 hours. Northern blot analysis revealed an increase in MCP-1 and IL-8 mRNA expression in MCG-treated ECs. Induction of these chemokines was attenuated by antitryptase neutralizing antibody. Furthermore, MCP-1 and IL-8 were induced in ECs by incubation with human mast cell tryptase, but not with chymase.


CONCLUSIONS
These results indicate that the production of MCP-1 and IL-8 in ECs was induced by MCG and amplified by tryptase.
Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, 54 Kawaharacho Shogoin, Kyoto, 606-8397, Japan.
Makoto
M
Kinoshita
Masaharu
M
Okada
Masatake
M
Hara
Yutaka
Y
Furukawa
Akira
A
Matsumori
D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism*; D053818:Chymases; D003594:Cytoplasmic Granules / Q000201:enzymology; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D008407:Mast Cells / Q000201:enzymology*; D012697:Serine Endopeptidases / Q000378:metabolism*; D053802:Tryptases; D014471:Umbilical Veins / Q000166:cytology; D014657:Vasculitis / Q000276:immunology / Q000378:metabolism*
C111835:CCL2 protein, human; D018932:Chemokine CCL2; D016209:Interleukin-8; D012697:Serine Endopeptidases; D053818:Chymases; D053802:Tryptases