Abstract
Capping and release of membranous, small (<1.5 μm) endothelial microparticles were quantified by immunofluorescence microscopy and flow cytometry after treatment of cultures of human renal microvascular endothelial cells with agonists tumor necrosis factor-alpha (TNF-α) or mitomycin C. For constitutive marker CD31, both agonist-treated attached, monolayer, and detached, free endothelial cells formed caps and released microparticles. TNF-α and mitomycin C induced dissimilar appearing CD31-containing caps after 3 h, followed by endothelial microparticle release after 6 h. The degree of capping correlated with increasing counts of released microparticles. For lymphokine-inducible CD54, TNF-α also induced CD54-containing caps and microparticle release, but mitomycin C failed to induce the expression of either entity. Neither capping nor microparticle release caused by TNF-α was part of an apoptotic pathway that involved caspase 3. Mitomycin C treatment of endothelial cells caused capping and microparticle release with a time course similar to TNF-α induction for 15 to 24 h, but assays for caspase 3 were positive, confirming the apoptotic action of mitomycin C. Membrane capping and microparticle release from endothelial cells are a convenient experimental model for studying protein movement, release of microparticles, and their possible biological significance.
Original language | English (US) |
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Pages (from-to) | 179-189 |
Number of pages | 11 |
Journal | Endothelium: Journal of Endothelial Cell Research |
Volume | 9 |
Issue number | 3 |
DOIs | |
State | Published - 2002 |
Keywords
- Caps
- Endothelial cells
- Immunofluorescence
- Microparticles
- Mitomycin C
- TNF-α
ASJC Scopus subject areas
- Physiology
- Cell Biology