152
|
Bozza FA, Shah AM, Weyrich AS, Zimmerman GA. Amicus or adversary: platelets in lung biology, acute injury, and inflammation. Am J Respir Cell Mol Biol 2008; 40:123-34. [PMID: 18723438 DOI: 10.1165/rcmb.2008-0241tr] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Platelets are the chief effector cells in hemostasis and have additional major functions in inflammation, vascular integrity, and tissue repair. Platelets and the lungs have interrelated activities. Previous studies provide evidence that platelets contribute to pulmonary vascular barrier function and are required for defense against pulmonary hemorrhage, and that the lungs can influence platelet number and distribution. There is also evidence that platelets contribute to pathologic syndromes of pulmonary inflammation and thrombosis. Thus, platelets have an "amicus or adversary" relationship with the lung. Recent observations and discoveries have established new paradigms relevant to influences of platelets on lung cell and molecular biology. These new findings are in a variety of areas including thrombopoieis, nontraditional activities of platelets, new synthetic capabilities and mechanisms of post-translational gene expression, interactions of platelets with endothelial cells and contributions to alveolar capillary barrier permeability, interactions of platelets with myeloid leukocytes, and platelet involvement in stem cell signaling and vascular repair. These issues are considered in a translational approach, with an emphasis on acute lung injury and the acute respiratory distress syndrome.
Collapse
Affiliation(s)
- Fernando A Bozza
- University of Utah, Program in Human Molecular Biology and Genetics, 15 North 2030 East, Room 4220, Salt Lake City, UT 84112-5330, USA.
| | | | | | | |
Collapse
|
154
|
Maroney SA, Ferrel JP, Collins ML, Mast AE. Tissue factor pathway inhibitor-gamma is an active alternatively spliced form of tissue factor pathway inhibitor present in mice but not in humans. J Thromb Haemost 2008; 6:1344-51. [PMID: 18503630 PMCID: PMC3549614 DOI: 10.1111/j.1538-7836.2008.03033.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Tissue factor pathway inhibitor (TFPI) is a potent inhibitor of tissue factor procoagulant activity produced as two alternatively spliced isoforms, TFPIalpha and TFPIbeta, which differ in domain structure and mechanism for cell surface association. 3' Rapid amplification of cDNA ends was used to search for new TFPI isoforms. TFPIgamma, a new alternatively spliced form of TFPI, was identified and characterized. METHODS The tissue expression, cell surface association and anticoagulant activity of TFPIgamma were characterized and compared to those of TFPIalpha and TFPIbeta through studies of mouse and human tissues and expression of recombinant proteins in Chinese hamster ovary (CHO) cells. RESULTS TFPIgamma is produced by alternative splicing using the same 5'-splice donor site as TFPIbeta and a 3'-splice acceptor site 276 nucleotides beyond the stop codon of TFPIbeta in exon 8. The resulting protein has the first two Kunitz domains connected to an 18 amino acid C-terminal region specific to TFPIgamma. TFPIgamma mRNA is differentially produced in mouse tissues but is not encoded within the human TFPI gene. When expressed in CHO cells, TFPIgamma is secreted into conditioned media and effectively inhibits tissue factor procoagulant activity. CONCLUSIONS TFPIgamma is a third alternatively spliced form of TFPI that is widely expressed in mouse tissues but not made by human tissues. It contains the first two Kunitz domains and is a secreted, rather than a cell surface-associated, protein. It is a functional anticoagulant and may partially explain the resistance of mice to coagulopathy in tissue factor-mediated models of disease.
Collapse
Affiliation(s)
- Susan A. Maroney
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI
| | | | | | - Alan E. Mast
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI
| |
Collapse
|
157
|
Brambilla M, Camera M, Colnago D, Marenzi G, De Metrio M, Giesen PL, Balduini A, Veglia F, Gertow K, Biglioli P, Tremoli E. Tissue Factor in Patients With Acute Coronary Syndromes. Arterioscler Thromb Vasc Biol 2008; 28:947-53. [DOI: 10.1161/atvbaha.107.161471] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective—
Activated platelets and circulating platelet-leukocyte aggregates (PLA) are significantly higher in patients with unstable angina than in those with stable angina (SA). Platelets from healthy subjects express TF on activation. The aim of this study was to investigate the expression of TF in PLA, in platelets, and in monocytes of acute coronary syndrome (ACS) patients compared to SA patients and healthy subjects (Controls).
Methods and Results—
We enrolled 26 consecutive patients with ACS, 29 patients with SA, and 25 Controls. A significantly greater number of total and TF positive platelet-monocyte aggregates was found by flow cytometry in blood of ACS patients than in either SA patients (3-fold) or Controls (5-fold). ACS patients also had a significantly higher amount of TF-positive platelets than SA or Controls (>3-fold) and significantly higher thrombin generation capacity. TF mRNA expression in platelets was significantly higher in ACS patients than in SA or Controls.
Conclusions—
In ACS patients the greater expression of TF in platelets and PLA strengthens the link between platelet activation, blood coagulation, and thrombus formation and may further contribute to the hypercoagulability associated with the disease.
Collapse
Affiliation(s)
- Marta Brambilla
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| | - Marina Camera
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| | - Deborah Colnago
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| | - Giancarlo Marenzi
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| | - Monica De Metrio
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| | - Peter L. Giesen
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| | - Alessandra Balduini
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| | - Fabrizio Veglia
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| | - Karl Gertow
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| | - Paolo Biglioli
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| | - Elena Tremoli
- From the Department of Pharmacological Sciences (M.B., M.C., E.T.), University of Milan, Italy; Centro Cardiologico Monzino IRCCS (M.C., D.C., G.M., M.D.M., F.V., K.G., P.B., E.T.), Milan, Italy; the Department of Biochemistry (A.B.), University of Pavia, Italy; and Thrombinoscope CV (P.L.G.), Maastricht, The Netherlands
| |
Collapse
|
160
|
Orfeo T, Brummel-Ziedins KE, Gissel M, Butenas S, Mann KG. The nature of the stable blood clot procoagulant activities. J Biol Chem 2008; 283:9776-86. [PMID: 18268016 DOI: 10.1074/jbc.m707435200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The function of tissue factor (Tf)-initiated coagulation is hemorrhage control through the formation and maintenance of an impermeable platelet-fibrin barrier. The catalytic processes involved in the clot maintenance function are not well defined, although the rebleeding problems characteristic of individuals with hemophilias A and B suggest a link between specific defects in the Tf-initiated process and defects in the maintenance function. We have previously demonstrated, using a methodology of "flow replacement" (or resupply) of ongoing Tf-initiated reactions with fresh reactants, that procoagulant complexes are produced during Tf-initiated coagulation, which are capable of reinitiating coagulation without input from extrinsic factor Xase activity (Orfeo, T., Butenas, S., Brummel-Ziedins, K. E., and Mann, K. G. (2005) J. Biol. Chem. 280, 42887-42896). Here we used Tf-initiated reactions in normal and hemophilia blood or in their corresponding proteome mixtures as sources of procoagulant end products and then varied the resupplying material to determine the identity of the catalysts that drive the new cycle of thrombin formation. The central findings are as follows: 1) the prothrombinase complex (fVa-fXa-Ca(2+)-membrane) accumulated during the episode of Tf-initiated coagulation is the primary catalyst responsible for the observed pattern of prothrombin activation after resupply; 2) impairments in intrinsic factor Xase function, i.e. hemophilias A and B, result in an impaired capacity to mount a resupply response; and 3) in normal hemostasis the intrinsic factor Xase function contributes to the durability of the resupply response.
Collapse
Affiliation(s)
- Thomas Orfeo
- Department of Biochemistry, University of Vermont, Colchester, VT 05446, USA
| | | | | | | | | |
Collapse
|
163
|
Crawley JTB, Lane DA. The haemostatic role of tissue factor pathway inhibitor. Arterioscler Thromb Vasc Biol 2007; 28:233-42. [PMID: 17951326 DOI: 10.1161/atvbaha.107.141606] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Under normal conditions the blood circulates freely within the confines of the vascular system, carrying oxygen, nutrients, and hormonal information around the body and removing metabolic waste. If blood gains access to extravascular sites, or the vasculature becomes pathologically challenged, hemostasis may be activated. This process is finely regulated by positive and negative feedback loops that modulate fibrin clot formation. Blood coagulation revolves around the activation and assembly of the components of the prothrombinase complex, which converts the inactive zymogen, prothrombin, into its active form, thrombin. This serine protease catalyzes the conversion of fibrinogen to fibrin, the structural scaffold that stabilizes platelet aggregates at sites of vascular injury. The extent of the hemostatic response is controlled by the action of inhibitory pathways, which ensure that thrombin activity and the spread of the hemostatic plug is limited to the site of vessel damage. This review article focuses on the major physiological regulator of tissue factor-induced coagulation, tissue factor pathway inhibitor, its expression, anticoagulant function, and its role in normal hemostasis.
Collapse
Affiliation(s)
- James T B Crawley
- Department of Hematology, Imperial College London, 5th Floor Commonwealth Building, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.
| | | |
Collapse
|