The Ratio of Factor VIIa:Tissue Factor Content within Microvesicles Determines the Differential Influence on Endothelial Cells
Tissue factor (TF)-positive microvesicles from various sources can promote cellular proliferation or alternatively induce apoptosis, but the determining factors are unknown. In this study the hypothesis that the ratio of fVIIa:TF within microvesicles determines this outcome was examined. Microvesicl...
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| Format: | Article |
| Language: | English |
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Georg Thieme Verlag KG
2019-04-01
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| Series: | TH Open |
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| Online Access: | http://www.thieme-connect.de/DOI/DOI?10.1055/s-0039-1688934 |
| _version_ | 1818137254317522944 |
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| author | Yahya Madkhali Sophie Featherby Mary E. Collier Anthony Maraveyas John Greenman Camille Ettelaie |
| author_facet | Yahya Madkhali Sophie Featherby Mary E. Collier Anthony Maraveyas John Greenman Camille Ettelaie |
| author_sort | Yahya Madkhali |
| collection | DOAJ |
| description | Tissue factor (TF)-positive microvesicles from various sources can promote cellular proliferation or alternatively induce apoptosis, but the determining factors are unknown. In this study the hypothesis that the ratio of fVIIa:TF within microvesicles determines this outcome was examined. Microvesicles were isolated from HepG2, BxPC-3, 786-O, MDA-MB-231, and MCF-7 cell lines and microvesicle-associated fVIIa and TF antigen and activity levels were measured. Human coronary artery endothelial cells (HCAECs) were incubated with these purified microvesicles, or with combinations of fVIIa-recombinant TF, and cell proliferation/apoptosis was measured. Additionally, by expressing mCherry-PAR2 on HCAEC surface, PAR2 activation was quantified. Finally, the activation of PAR2 on HCAEC or the activities of TF and fVIIa in microvesicles were blocked prior to addition of microvesicles to cells. The purified microvesicles exhibited a range of fVIIa:TF ratios with HepG2 and 786-O cells having the highest (54:1) and lowest (10:1) ratios, respectively. The reversal from proapoptotic to proliferative was estimated to occur at a fVIIa:TF molar ratio of 15:1, but HCAEC could not be rescued at higher TF concentrations. The purified microvesicles induced HCAEC proliferation or apoptosis according to this ruling. Blocking PAR2 activation on HCAEC, or inhibiting fVIIa or TF-procoagulant function on microvesicles prevented the influence on HCAEC. Finally, incubation of HCAEC with recombinant TF resulted in increased surface exposure of fVII. The induction of cell proliferation or apoptosis by TF-positive microvesicles is dependent on the ratio of fVIIa:TF and involves the activation of PAR2. At lower TF concentrations, fVIIa can counteract the proapoptotic stimulus and induce proliferation. |
| first_indexed | 2024-12-11T09:53:23Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 2512-9465 2512-9465 |
| language | English |
| last_indexed | 2024-12-11T09:53:23Z |
| publishDate | 2019-04-01 |
| publisher | Georg Thieme Verlag KG |
| record_format | Article |
| series | TH Open |
| spelling | doaj.art-2cbf586342f94485b8d8d2cf88e5a4182022-12-22T01:12:21ZengGeorg Thieme Verlag KGTH Open2512-94652512-94652019-04-010302e132e14510.1055/s-0039-1688934The Ratio of Factor VIIa:Tissue Factor Content within Microvesicles Determines the Differential Influence on Endothelial CellsYahya Madkhali0Sophie Featherby1Mary E. Collier2Anthony Maraveyas3John Greenman4Camille Ettelaie5Department of Biomedical Sciences, University of Hull, Hull, United KingdomDepartment of Biomedical Sciences, University of Hull, Hull, United KingdomDepartment of Cardiovascular Sciences, University of Leicester, Glenfield General Hospital, Leicester, United KingdomDivision of Cancer–Hull York Medical School, University of Hull, Hull, United KingdomDepartment of Biomedical Sciences, University of Hull, Hull, United KingdomDepartment of Biomedical Sciences, University of Hull, Hull, United KingdomTissue factor (TF)-positive microvesicles from various sources can promote cellular proliferation or alternatively induce apoptosis, but the determining factors are unknown. In this study the hypothesis that the ratio of fVIIa:TF within microvesicles determines this outcome was examined. Microvesicles were isolated from HepG2, BxPC-3, 786-O, MDA-MB-231, and MCF-7 cell lines and microvesicle-associated fVIIa and TF antigen and activity levels were measured. Human coronary artery endothelial cells (HCAECs) were incubated with these purified microvesicles, or with combinations of fVIIa-recombinant TF, and cell proliferation/apoptosis was measured. Additionally, by expressing mCherry-PAR2 on HCAEC surface, PAR2 activation was quantified. Finally, the activation of PAR2 on HCAEC or the activities of TF and fVIIa in microvesicles were blocked prior to addition of microvesicles to cells. The purified microvesicles exhibited a range of fVIIa:TF ratios with HepG2 and 786-O cells having the highest (54:1) and lowest (10:1) ratios, respectively. The reversal from proapoptotic to proliferative was estimated to occur at a fVIIa:TF molar ratio of 15:1, but HCAEC could not be rescued at higher TF concentrations. The purified microvesicles induced HCAEC proliferation or apoptosis according to this ruling. Blocking PAR2 activation on HCAEC, or inhibiting fVIIa or TF-procoagulant function on microvesicles prevented the influence on HCAEC. Finally, incubation of HCAEC with recombinant TF resulted in increased surface exposure of fVII. The induction of cell proliferation or apoptosis by TF-positive microvesicles is dependent on the ratio of fVIIa:TF and involves the activation of PAR2. At lower TF concentrations, fVIIa can counteract the proapoptotic stimulus and induce proliferation.http://www.thieme-connect.de/DOI/DOI?10.1055/s-0039-1688934tissue factormicrovesiclesprotease-activated receptor-2apoptosiscell proliferationfactor viia |
| spellingShingle | Yahya Madkhali Sophie Featherby Mary E. Collier Anthony Maraveyas John Greenman Camille Ettelaie The Ratio of Factor VIIa:Tissue Factor Content within Microvesicles Determines the Differential Influence on Endothelial Cells TH Open tissue factor microvesicles protease-activated receptor-2 apoptosis cell proliferation factor viia |
| title | The Ratio of Factor VIIa:Tissue Factor Content within Microvesicles Determines the Differential Influence on Endothelial Cells |
| title_full | The Ratio of Factor VIIa:Tissue Factor Content within Microvesicles Determines the Differential Influence on Endothelial Cells |
| title_fullStr | The Ratio of Factor VIIa:Tissue Factor Content within Microvesicles Determines the Differential Influence on Endothelial Cells |
| title_full_unstemmed | The Ratio of Factor VIIa:Tissue Factor Content within Microvesicles Determines the Differential Influence on Endothelial Cells |
| title_short | The Ratio of Factor VIIa:Tissue Factor Content within Microvesicles Determines the Differential Influence on Endothelial Cells |
| title_sort | ratio of factor viia tissue factor content within microvesicles determines the differential influence on endothelial cells |
| topic | tissue factor microvesicles protease-activated receptor-2 apoptosis cell proliferation factor viia |
| url | http://www.thieme-connect.de/DOI/DOI?10.1055/s-0039-1688934 |
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