Coagulation factor IX (FIX) is an essential plasma protein for blood coagulation. The first epidermal growth factor motif of FIX (EGF-F9) has been reported to attenuate cell adhesion to the extracellular matrix. The purpose of this study was to determine the effects of this motif on cell adhesion and apoptosis. Treatment with a recombinant EGF-F9 attenuated cell adhesion to the extracellular matrix within ten minutes. De-adhesion assays with native FIX recombinant FIX deletion mutant proteins suggested that the de-adhesion activity of EGF-F9 requires the same process of FIX activation as that which occurs for coagulation activity. The recombinant EGF-F9 increased LDH activity release into the medium, and increased the number of cells stained with annexin V, and activated caspase-3, by 8.8 and 2.7 fold, respectively, indicating that EGF-F9 induced apoptosis. Activated caspase-3 increased very rapidly after only 5 min of administration of recombinant EGF-F9. Treatment with EGF-F9 increased the level of phosphorylated p38 MAPK, but not that of phosphorylated MAPK 44/42 or JNK. Inhibitors of caspase-3 suppressed the release of LDH. Caspase-3 inhibitors also suppressed the attenuation of cell adhesion and phosphorylation of p38 MAPK by EGF-F9. Our data indicated that EGF-F9 activated signals for apoptosis and induced de-adhesion in a caspase-3 dependent manner.
- coagulation factor
- epidermal growth factor
- cell adhesion
- ©2016 The Author(s)
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