Plasminogen activation by fibroblasts from periodontal ligament and gingiva is not directly affected by chemokines in vitro.
OBJECTIVE
Chronic inflammation in periodontal disease is associated with increased plasminogen activation and elevated levels of chemokines. It is unknown whether chemokines can regulate the activation of plasminogen via modulation of plasminogen activators (PA) and the corresponding plasminogen activator inhibitors (PAI) in periodontal tissue.


METHODS
To establish a link between chemokines and activation of plasminogen, human periodontal ligament fibroblasts (PDL) and gingival fibroblasts (GF) were incubated with IL-8, monocyte chemoattractant protein-1, macrophage inflammatory protein-1alpha, and platelet factor-4, either alone or in the presence of the inflammatory mediators TGF-beta and IL-1. The potential of the cell lysates to activate plasminogen was based on kinetic studies with the substrate casein. Casein zymography was performed to determine the molecular sizes of the PA. Total PAI-1 in the cell-conditioned medium was quantified by immunoassay.


RESULTS
We report that the chemokines did not affect activation of plasminogen by PDL and GF. Even in the presence of TGF-beta which suppressed, and IL-1 which stimulated plasminogen activation, the chemokines had no direct effect. Inhibition of PA and plasmin, but not of matrix metalloproteinases and cysteine proteinases prevented caseinolysis. The plasminogen activation capacity of the cell lysates was represented by a single band with features of uPA. The immunoassay showed that the release of PAI-1 in PDL and GF remained unaffected by the chemokines, also when stimulated with TGF-beta.


CONCLUSIONS
These results suggest that plasminogen activation by PDL and GF is not directly affected by the chemokines even in the presence of the inflammatory mediators TGF-beta and IL-1.
Sarajlic
Jasna
J
Department of Oral Surgery, Medical University of Vienna, Vienna, Austria, Währingerstrasse 25a, A-1090 Vienna, Austria.
Agis
Hermann
H
Kandler
Barbara
B
Watzek
Georg
G
Gruber
Reinhard
R
D002364:Caseins / Q000378:metabolism; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000494:pharmacology; D054405:Chemokine CCL3 / Q000494:pharmacology; D018925:Chemokines / Q000494:pharmacology*; D017077:Culture Media, Conditioned; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D005881:Gingiva / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D018836:Inflammation Mediators / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D016209:Interleukin-8 / Q000494:pharmacology; D061965:Matrix Metalloproteinase Inhibitors; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010958:Plasminogen / Q000187:drug effects / Q000378:metabolism*; D010960:Plasminogen Activators / Q000032:analysis / Q000187:drug effects; D015849:Plasminogen Inactivators / Q000378:metabolism; D010978:Platelet Factor 4 / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D014568:Urokinase-Type Plasminogen Activator / Q000032:analysis
D002364:Caseins; D018932:Chemokine CCL2; D054405:Chemokine CCL3; D018925:Chemokines; D017077:Culture Media, Conditioned; D015853:Cysteine Proteinase Inhibitors; D018836:Inflammation Mediators; D007375:Interleukin-1; D016209:Interleukin-8; D061965:Matrix Metalloproteinase Inhibitors; D015849:Plasminogen Inactivators; D016212:Transforming Growth Factor beta; D010978:Platelet Factor 4; D010958:Plasminogen; D010960:Plasminogen Activators; D014568:Urokinase-Type Plasminogen Activator