Thrombin promotes endothelial cell alignment in Matrigel in vitro and angiogenesis in vivo

Abstract

We have tested the effect of thrombin on endothelial cell tube formation in vitro and angiogenesis in vivo. Thrombin induces the differentiation of endothelial cells into capillary structures in a dose-dependent fashion (0.1-0.3 units thrombin/ml) on Matrigel, a laminin-rich reconstituted basement membrane matrix. At higher thrombin concentrations (1.0 unit/ml), a suppression of tube formation is evident, probably due to downregulation (desensitization) of the thrombin receptor. D-Phe-Pro-Arg-CH2Cl-thrombin is without effect when used alone, but it abolishes the tube-promoting effect of thrombin when used in combination with thrombin, indicating the involvement of the catalytic site of thrombin. Activation of protein kinase C (PKC) seems to be the transduction mechanism involved in the stimulation of tube formation by thrombin. Ro-318220 (3 micrograms/ml), a specific inhibitor of PKC, completely abolishes the stimulatory effect of thrombin. In the in vivo Matrigel system of angiogenesis, there is a 10-fold increase in endothelial cell infiltration in response to thrombin. These results provide evidence for the angiogenesis-promoting effect of thrombin in vivo and the induction by thrombin of the angiogenic phenotype of endothelial cells in vitro in the absence of other cell types such as smooth muscle cells, pericytes, and inflammatory cells.

Human mesenchymal stem cells overexpressing pigment epithelium-derived factor inhibit hepatocellular carcinoma in nude mice

“…When human umbilical vein endothelial cells are cultured on Matrigel, they rapidly align and form hollow tube-like structures (Haralabopoulos et al, 1994). The CM derived from hMSCs-GFP did not affect tube formation.…”

Dabigatran Potentiates Gemcitabine-Induced Growth Inhibition of Pancreatic Cancer in Mice

“…This is somewhat puzzling, as thrombin is known to enhance angiogenesis (44), and anticoagulants inhibit tumor cell-mediated angiogenesis (45). Interestingly, however, low thrombin levels (i.e., 0.1-0.3 U/ mL) more potently induce angiogenesis as compared with high (i.e., 1 U/mL) thrombin levels (46), suggesting that residual thrombin activity in dabigatran-treated mice might actually induce angiogenesis. In line, some studies do show that thrombin inhibits angiogenesis in vitro (47), whereas both FX and FXa possess anti-angiogenic properties in vitro in zebra fish intersegmental vasculature formation and in chick embryo chorioallantoic membrane assays (48).…”

Protease-activated receptors in cancer: A systematic review

“…Although thrombin is best known for its direct role in clot formation via platelet activation and fibrin deposition, a number of the effects of thrombin in cancer may be mediated by promoting angiogenesis in vivo (17)(18)(19). Numerous cellular effects of thrombin on endothelial cells contribute to the angiogenic action of thrombin (Table I) (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30).…”