Format

Send to

Choose Destination
See comment in PubMed Commons below
J Lab Clin Med. 2001 Dec;138(6):393-402.

Simultaneous engagement of thrombin and Fc gamma RIIA receptors results in platelets expressing high levels of procoagulant proteins.

Author information

1
W. K. Warren Medical Research Institute and the Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, 73190, USA.

Abstract

Collagen and thrombin-activated (COAT) platelets represent a unique subset of activated platelets that exhibit high levels of several adhesive and procoagulant alpha-granule proteins on their surface. In this report we demonstrate that a similar subpopulation of platelets can also be generated by the combined stimulation of Fc gamma RIIA and thrombin receptors. Platelets activated in this manner are referred to as Fc receptor and thrombin-activated (FcRT) platelets, and they share many of the characteristics of the formerly observed COAT platelets, including aminophospholipid exposure, adhesive and procoagulant protein enrichment, increased frequency among young platelets, and sensitivity to transglutaminase inhibitors. Although Fc gamma RIIA receptor activation can be achieved either with anti-CD9 monoclonal antibodies (ALB-6 and ML-13) or with direct Fc receptor cross-linking, FcRT platelet generation occurs only with concurrent or slightly delayed thrombin stimulation. In fact, when thrombin was the second agonist, time delays of up to 120 seconds after Fc gamma RIIA receptor stimulation had little effect on the generation of FcRT platelets; however, a similar delay for convulxin plus thrombin activation results in a 90% diminution in COAT platelet production. FcRT platelet formation in platelet-poor plasma and whole blood was also investigated, and results were similar to those observed with gel-filtered platelets. Previous experiments with COAT platelet formation used physiologic agonists (collagen and thrombin) that might be encountered under either physiologic or pathologic conditions; however, the current experiments with Fc receptor stimulation offer the first example in which these highly prohemostatic platelets are likely to be strictly pathogenic.

PMID:
11753286
DOI:
10.1067/mlc.2001.120049
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center