Biochemical properties of platelet microparticle membranes formed during exocytosis resemble organelles more than plasma membrane

Olas, Beata; Lundell, Kerstin; Holmsen, Holm; Fukami, Miriam H.

doi:10.1016/s0014-5793(02)03060-0

Cited by 6 publications

(3 citation statements)

References 38 publications

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“…The intracellular mechanisms underlying the release of microparticles are as yet not fully understood, but they seem to be associated – among others – with the inducing stimulus leading to the actual vesiculation. It is now becoming apparent that the formation of microparticles is a highly regulated process: the phospholipid composition of PMPs shows characteristics from intracellular rather than from plasma membrane fractions and recent studies in endothelial cells showed that constitutively exposed proteins from these cells are hardly transmitted to endothelial‐cell‐derived microparticles [25,26].…”

Section: Characterization Of Microparticles: Size and Compositionmentioning

confidence: 99%

Cellular microparticles: new players in the field of vascular disease?

Diamant

Tushuizen

Sturk

et al. 2004

Eur J Clin Investigation

338

264

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Microparticles are small membrane vesicles that are released from cells upon activation or during apoptosis. Cellular microparticles in body fluids constitute a heterogeneous population, differing in cellular origin, numbers, size, antigenic composition and functional properties. Microparticles support coagulation by exposure of negatively charged phospholipids and sometimes tissue factor, the initiator of coagulation in vivo . Microparticles may transfer bioactive molecules to other cells or microparticles, thereby stimulating cells to produce cytokines, cell-adhesion molecules, growth factors and tissue factor, and modulate endothelial functions. Microparticles derived from various cells, most notably platelets but also leucocytes, lymphocytes, erythrocytes and endothelial cells, are present in the circulation of healthy subjects. Rare hereditary syndromes with disturbances in membrane vesiculation leading to a decreased numbers of microparticles clinically present with a bleeding tendency. In contrast, elevated numbers of microparticles are encountered in patients with a great variety of diseases with vascular involvement and hypercoagulability, including disseminated intravascular coagulation, acute coronary syndromes, peripheral arterial disease, diabetes mellitus and systemic inflammatory disease. Finally, microparticles are a major component of human atherosclerotic plaques. In view of their functional properties, cell-derived microparticles may be an important intermediate in the cascade of cellular and plasmatic dysfunctions underlying the process of atherogenesis.

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Section: Characterization Of Microparticles: Size and Compositionmentioning

confidence: 99%

Cellular microparticles: new players in the field of vascular disease?

Diamant

Tushuizen

Sturk

et al. 2004

Eur J Clin Investigation

338

264

View full text Add to dashboard Cite

show abstract

“…Small membrane-derived vesicles (microparticles, microvesicles) can either be formed on cellular surfaces (ectosomes), or within the endosomal pathway (exosomes) and are then released into the extracellular environment [55] by a number of cell types, including platelets, leukocytes, endothelial cells and smooth muscle cells, especially when the cells are undergoing activation, apoptosis [56] or malignant transformation [57] . Microparticles vary in size and composition, generally as a result of their source and formation process [55] .…”

Section: Circulating Tissue Factormentioning

confidence: 99%

Tissue Factor and Cancer

Milsom

Rak

2007

Pathophysiol Haemos Thromb

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Tissue factor (TF), the key regulator of haemostasis and angiogenesis, is also involved in the pathology of several diseases, including cardiovascular, inflammatory and neoplastic conditions. In the latter, TF is upregulated by cancer cells, as well as by certain host cells, and it is the interactions between these distinct pools of TF-expressing cells that likely influence tumour progression in several ways. Furthermore, the release of TF microparticles into the circulation is thought to contribute to the systemic coagulopathies commonly observed in cancer patients. The direct regulation of TF by oncogenic events has provided a plausible explanation for the relatively common overexpression of TF in various cancers and its involvement in tumour growth, angiogenesis, metastasis and coagulopathy. However, this constitutive influence is modified by the tumour microenvironment, cellular interactions and host factors rendering TF expression patterns complex and heterogeneous. It appears that in many biological contexts TF plays a central role in disease progression and thereby potentially constitutes an attractive therapeutic target, especially in scenarios where the risk of bleeding can be avoided by selecting appropriate medications, refined dosing or by targeting the signalling component of TF activity. The efficacy and safety of such approaches still awaits clinical verification.

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“…33 A recent study of platelet MV formation found that concanavalin A-FITC stained platelet plasma membranes do not result in concanavalin A-stained microvesicles, which among other findings led the authors to conclude that the membranes of microvesicles resemble organelles rather than platelet plasma membrane. 34 Platelet a granules can be thus considered as a sole source of the procoagulant activity of activated platelets. A detectable increase in PF3 activity seems to always accompany an increase in acid phosphatase activity.…”

mentioning

confidence: 99%

Procoagulant potential of platelet α granules

Polasek

2004

Platelets

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In this brief review of the literature it is pointed out that during platelet activation and degranulation platelet alpha granules leave the platelet interior through blebs in platelet plasma membrane and through the tips of the pseudopods, and then accumulate in the external milieu. There they undergo disintegration and secondary adhesion to the platelet plasma membranes. During their disintegration they expose their tightly packed GPIIb-IIIa complexes, annexin V stainable aminophospholipids, factor V, and the membrane markers CD62 and CD63. There is also demasking of lysosomal acid phosphatase activity and microvesicle formation. Lysosomal nature of platelet alpha granules is mentioned. It is suggested that platelet alpha granules are the sole source of platelet procoagulant activity and platelet microparticles (MP) or microvesicles (MV). The implications of this concept for antiplatelet therapy are discussed. A relationship of this process to tissue factor exposure and apoptosis is suggested.

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Biochemical properties of platelet microparticle membranes formed during exocytosis resemble organelles more than plasma membrane

Cited by 6 publications

References 38 publications

Cellular microparticles: new players in the field of vascular disease?

Cellular microparticles: new players in the field of vascular disease?

Tissue Factor and Cancer

Procoagulant potential of platelet α granules

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