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author:("marches, M J")
1.  Human mast cells stimulate vascular tube formation. Tryptase is a novel, potent angiogenic factor. 
Journal of Clinical Investigation  1997;99(11):2691-2700.
The presence of mast cells near capillary sprouting sites suggests an association between mast cells and angiogenesis. However, the role of mast cells in blood vessel development remains to be defined. In an attempt to elucidate this relationship, we investigated the effect of human mast cells (HMC-1) and their products on human dermal microvascular endothelial cell (HDMEC) tube formation. Coculture of HMC-1 with HDMEC led to a dose-response increase in the network area of vascular tube growth. Moreover, the extent of neovascularization was enhanced greatly when HMC-1 were degranulated in the presence of HDMEC. Further examination using antagonists to various mast cell products revealed a blunted response (73-88% decrease) in the area of vascular tube formation if specific inhibitors of tryptase were present. Tryptase (3 microg/ml) directly added to HDMEC caused a significant augmentation of capillary growth, which was suppressed by specific tryptase inhibitors. Tryptase also directly induced cell proliferation of HDMEC in a dose-dependent fashion (2 pM-2 nM). Our results suggest that mast cells act at sites of new vessel formation by secreting tryptase, which then functions as a potent and previously unrecognized angiogenic factor.
PMCID: PMC508115  PMID: 9169499
2.  Anti-IgE autoantibodies in systemic sclerosis (scleroderma). 
Annals of the Rheumatic Diseases  1989;48(3):201-205.
An enzyme immunoassay was used to determine the prevalence of anti-IgE auto-antibodies in 66 patients with systemic sclerosis (scleroderma) stratified according to extent and duration of disease. Serum IgG anti-IgE antibodies were detected in 14 (21%) patients and IgM anti-IgE antibodies in nine (14%) patients. The overall prevalence of IgG or IgM isotypes was 21/66, (32%). Anti-IgE autoantibodies were not found in six patients with undifferentiated connective tissue disease or two patients with eosinophilic fasciitis. Attempts to demonstrate histamine release from basophils in vitro by using serum samples containing high titre anti-IgE antibody were unsuccessful. By multivariate analysis the presence of anti-IgE antibody was not associated with duration of systemic sclerosis; extent of scleroderma; specific visceral features, including heart, lung, renal, and gastrointestinal involvement; or mortality.
PMCID: PMC1003721  PMID: 2930275
3.  Synovial procollagenase activation by human mast cell tryptase dependence upon matrix metalloproteinase 3 activation. 
Journal of Clinical Investigation  1989;84(5):1657-1662.
Mast cells have been implicated in the pathogenesis of the matrix degradation observed in the cartilaginous and osseous structures of the rheumatoid joint. We previously reported that human mast cell tryptase, a 134-kD granule-associated neutral protease, is present in rheumatoid synovium and can activate collagenase in crude culture medium in vitro. the present study attempts to depict the precise mechanism of this activation. To express full activation of latent collagenase, matrix metalloproteinase 3 (MMP-3) or stromelysin, can be activated by tryptase in a time and dose-dependent manner. Tryptase was not capable of generating active collagenase in the crude media from cultured rheumatoid synoviocytes depleted of proMMP-3 by immunoadsorption. In addition, the function of the tissue inhibitor of metalloproteinases (TIMP) was not altered by tryptase, and SDS-PAGE analysis revealed no degradation of TIMP by tryptase. The tryptase dependent activation of synoviocyte procollagenase thereby appears to be entirely dependent upon its ability to activate proMMP-3.
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PMCID: PMC304033  PMID: 2553780

Results 1-3 (3)