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Enhancement of fibrinogen-triggered pro-coagulant activation of monocytes in vitro by matrix metalloproteinase-9.

Kaneider NC, Mosheimer B, Günther A, Feistritzer C, Wiedermann CJ - Thromb J (2010)

Bottom Line: Fibrinogen and its digestion fragment D induced pro-coagulant activation of monocytes as assessed in a cellular coagulation assay by reductions in clotting times.A selective inhibitor of matrix metalloproteinase-9 increased times to clot formation whereas other matrix metalloproteinase inhibitors did not significantly interfere with fibrinogen-augmented clot formation in this assay.Results provide further evidence that mediators of hemostasis have a profound impact on cells of the immune system and are closely related to inflammatory pathways.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Internal Medicine, Central Hospital of Bolzano, Lorenz-Böhler-Street 5, 39100 Bolzano (BZ), Italy. christian.wiedermann@asbz.it.

ABSTRACT

Background: Interaction of fibrinogen with specific leukocyte integrins of monocytes may link coagulation and inflammation, however, the precise mechanism of fibrinogen leading to the pro-inflammatory and pro-coagulatory response on monocytes is yet unknown.

Results: Fibrinogen and its digestion fragment D induced pro-coagulant activation of monocytes as assessed in a cellular coagulation assay by reductions in clotting times. Pro-coagulant activation was reversed by blocking antibodies against Mac-1 or LFA-1. Pre-exposure of monocytes to the p38 MAPK inhibitor SB 202190 and the MEK1.2 inhibitor U0126 led to significant increasees in coagulation times whereas blocking JNKII with its inhibitor had no such effect. Blocking NFkappaB with MG-132 also inhibited pro-coagulant activation of monocytes by fibrinogen. A selective inhibitor of matrix metalloproteinase-9 increased times to clot formation whereas other matrix metalloproteinase inhibitors did not significantly interfere with fibrinogen-augmented clot formation in this assay. Treatment of monocytes with fibrinogen increased concentrations of matrix metalloproteinase-9 immunoreactivity in their supernatants.

Conclusions: Fibrinogen induces monocyte pro-coagulant activation in an integrin-, nuclear factor kappaB-, p38 MAPK-, and MEK1.2-dependent manner. Activation of monocytes by fibrinogen increases metalloproteinase-9 secretion, metalloproteinase-9 itself enhances monocyte coagulation by an autocrine mechanism. Results provide further evidence that mediators of hemostasis have a profound impact on cells of the immune system and are closely related to inflammatory pathways.

No MeSH data available.


Related in: MedlinePlus

Inhibition of MMP-9 decreases the fibrinogen-triggered pro-coagulant activation of human monocytes. Monocytes were pre-treated with specific inhibitors of matrix metalloproteases (MMP)-1, -3, -8, -9 and -13, and exposed to fibrinogen. Then coagulation experiments were performed. The inhibitor of MMP-9 increased the time to clot formation to 355 ± 23.4 sec which was about the same for un-treated cells. Other MMP inhibitors did not interfere with fibrinogen-initiated clot formation. Results are given as mean ± SEM, n = 3. MMP-9: p < 0.05.
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Figure 5: Inhibition of MMP-9 decreases the fibrinogen-triggered pro-coagulant activation of human monocytes. Monocytes were pre-treated with specific inhibitors of matrix metalloproteases (MMP)-1, -3, -8, -9 and -13, and exposed to fibrinogen. Then coagulation experiments were performed. The inhibitor of MMP-9 increased the time to clot formation to 355 ± 23.4 sec which was about the same for un-treated cells. Other MMP inhibitors did not interfere with fibrinogen-initiated clot formation. Results are given as mean ± SEM, n = 3. MMP-9: p < 0.05.

Mentions: The major ligand-binding site within the α-chain of leukocyte integrins is called inserted domain (I-domain) and is homologous to the A domains of von Willebrand factor [12]. Interestingly, matrix metalloproteinase-9 (MMP-9), the most abundant MMP produced by monocytes, also binds to this I-domain of integrins and initiates the adhesion process [13]. Therefore, we performed cellular coagulation experiments in the presence of MMP-inhibitors. Again, cells were activated by fibrinogen and co-treated with MMP-inhibitors. Pre-treatment with a MMP-9 inhibitor completely reversed fibrinogen-induced clot formation of monocytes, whereas multiple other MMP inhibitors directed towards MMP-1, MMP-3, MMP-8, and MMP-13, did not affect monocyte aggregation (Fig. 5). Inhibition of various MMPs did not influence the coagulation time of untreated monocytes (data not shown).


Enhancement of fibrinogen-triggered pro-coagulant activation of monocytes in vitro by matrix metalloproteinase-9.

Kaneider NC, Mosheimer B, Günther A, Feistritzer C, Wiedermann CJ - Thromb J (2010)

Inhibition of MMP-9 decreases the fibrinogen-triggered pro-coagulant activation of human monocytes. Monocytes were pre-treated with specific inhibitors of matrix metalloproteases (MMP)-1, -3, -8, -9 and -13, and exposed to fibrinogen. Then coagulation experiments were performed. The inhibitor of MMP-9 increased the time to clot formation to 355 ± 23.4 sec which was about the same for un-treated cells. Other MMP inhibitors did not interfere with fibrinogen-initiated clot formation. Results are given as mean ± SEM, n = 3. MMP-9: p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2837620&req=5

Figure 5: Inhibition of MMP-9 decreases the fibrinogen-triggered pro-coagulant activation of human monocytes. Monocytes were pre-treated with specific inhibitors of matrix metalloproteases (MMP)-1, -3, -8, -9 and -13, and exposed to fibrinogen. Then coagulation experiments were performed. The inhibitor of MMP-9 increased the time to clot formation to 355 ± 23.4 sec which was about the same for un-treated cells. Other MMP inhibitors did not interfere with fibrinogen-initiated clot formation. Results are given as mean ± SEM, n = 3. MMP-9: p < 0.05.
Mentions: The major ligand-binding site within the α-chain of leukocyte integrins is called inserted domain (I-domain) and is homologous to the A domains of von Willebrand factor [12]. Interestingly, matrix metalloproteinase-9 (MMP-9), the most abundant MMP produced by monocytes, also binds to this I-domain of integrins and initiates the adhesion process [13]. Therefore, we performed cellular coagulation experiments in the presence of MMP-inhibitors. Again, cells were activated by fibrinogen and co-treated with MMP-inhibitors. Pre-treatment with a MMP-9 inhibitor completely reversed fibrinogen-induced clot formation of monocytes, whereas multiple other MMP inhibitors directed towards MMP-1, MMP-3, MMP-8, and MMP-13, did not affect monocyte aggregation (Fig. 5). Inhibition of various MMPs did not influence the coagulation time of untreated monocytes (data not shown).

Bottom Line: Fibrinogen and its digestion fragment D induced pro-coagulant activation of monocytes as assessed in a cellular coagulation assay by reductions in clotting times.A selective inhibitor of matrix metalloproteinase-9 increased times to clot formation whereas other matrix metalloproteinase inhibitors did not significantly interfere with fibrinogen-augmented clot formation in this assay.Results provide further evidence that mediators of hemostasis have a profound impact on cells of the immune system and are closely related to inflammatory pathways.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Internal Medicine, Central Hospital of Bolzano, Lorenz-Böhler-Street 5, 39100 Bolzano (BZ), Italy. christian.wiedermann@asbz.it.

ABSTRACT

Background: Interaction of fibrinogen with specific leukocyte integrins of monocytes may link coagulation and inflammation, however, the precise mechanism of fibrinogen leading to the pro-inflammatory and pro-coagulatory response on monocytes is yet unknown.

Results: Fibrinogen and its digestion fragment D induced pro-coagulant activation of monocytes as assessed in a cellular coagulation assay by reductions in clotting times. Pro-coagulant activation was reversed by blocking antibodies against Mac-1 or LFA-1. Pre-exposure of monocytes to the p38 MAPK inhibitor SB 202190 and the MEK1.2 inhibitor U0126 led to significant increasees in coagulation times whereas blocking JNKII with its inhibitor had no such effect. Blocking NFkappaB with MG-132 also inhibited pro-coagulant activation of monocytes by fibrinogen. A selective inhibitor of matrix metalloproteinase-9 increased times to clot formation whereas other matrix metalloproteinase inhibitors did not significantly interfere with fibrinogen-augmented clot formation in this assay. Treatment of monocytes with fibrinogen increased concentrations of matrix metalloproteinase-9 immunoreactivity in their supernatants.

Conclusions: Fibrinogen induces monocyte pro-coagulant activation in an integrin-, nuclear factor kappaB-, p38 MAPK-, and MEK1.2-dependent manner. Activation of monocytes by fibrinogen increases metalloproteinase-9 secretion, metalloproteinase-9 itself enhances monocyte coagulation by an autocrine mechanism. Results provide further evidence that mediators of hemostasis have a profound impact on cells of the immune system and are closely related to inflammatory pathways.

No MeSH data available.


Related in: MedlinePlus