| Autor: |
Collier ME; Dr. Mary Collier, Biomedical Section, Department of Biological Sciences, University of Hull, Hull, HU6 7RX, UK, Tel.: +44 1482 465528; Fax: +44 1482 465458, E-mail: mary_collier8@hotmail.com., Maraveyas A, Ettelaie C |
| Jazyk: |
angličtina |
| Zdroj: |
Thrombosis and haemostasis [Thromb Haemost] 2014 Apr 01; Vol. 111 (4), pp. 647-55. Date of Electronic Publication: 2013 Nov 21. |
| DOI: |
10.1160/TH13-09-0769 |
| Abstrakt: |
We previously reported that the incorporation of tissue factor (TF) into cell-derived microvesicles (MVs) is regulated by the phosphorylation of the cytoplasmic domain of TF. Since the cytoskeletal protein filamin-A is known to bind to the cytoplasmic domain of TF in a phosphorylation-dependent manner, the involvement of filamin-A in the incorporation of TF into MVs was examined. Endothelial cells were transfected to express TF, whereas MDA-MB-231 cells were used to examine endogenously expressed TF. MV release was induced by activating protease-activated receptor-2 (PAR2). Partial suppression of filamin-A expression using two different filamin-A siRNA sequences resulted in significant reductions in the incorporation of TF antigen into MVs as determined by TF-ELISA and western blot analysis, and was reflected in reduced thrombin-generation and FXa-generation capacities of these MVs. Deletion of the cytoplasmic domain of TF also resulted in reduced incorporation of TF into MVs, whereas the suppression of filamin-A expression had no additional effect on the incorporation of truncated TF into MVs. Partial suppression of filamin-A expression had no effect on the number and size distribution of the released MVs. However, >90% suppression of filamin-A expression resulted in increased MV release, possibly as a result of increased instability of the plasma membrane and underlying cytoskeleton. In conclusion, the presence of filamin-A appears to be essential for the incorporation of TF into MVs following PAR2 activation, but is not required for the process of MV formation and release following PAR2 activation. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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