1
|
Allosteric modulation of exosite 1 attenuates polyphosphate-catalyzed activation of factor XI by thrombin. JOURNAL OF THROMBOSIS AND HAEMOSTASIS : JTH 2023; 21:83-93. [PMID: 36695400 DOI: 10.1016/j.jtha.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 10/05/2022] [Accepted: 10/31/2022] [Indexed: 01/11/2023]
Abstract
BACKGROUND Polyphosphate (polyP) promotes feedback activation of factor (F) XI by thrombin by serving as a template. The contribution of thrombin's exosites to these interactions is unclear. OBJECTIVES To determine the contribution of thrombin exosites 1 and 2 to polyP-induced potentiation of FXI activation by thrombin. METHODS The affinities of α-thrombin; K109E/110E-thrombin, an exosite 1 variant, or R93E-thrombin, an exosite 2 variant; FXI; and FXIa for polyP-70 were quantified using surface plasmon resonance in the absence or presence of exosite ligands. FXI was activated with α-thrombin or thrombin variants in the absence or presence of polyP-70 and exosite ligands. RESULTS α-Thrombin, K109/110E-thrombin, FXI, and FXIa bound polyP-70, whereas R93E-thrombin exhibited minimal binding. Exosite 1 and exosite 2 ligands attenuated thrombin binding to polyP-70. PolyP-70 accelerated the rate of FXI activation by α-thrombin and K109E/110E-thrombin but not R93E-thrombin up to 1500-fold in a bell-shaped, concentration-responsive manner. Exosite 1 and exosite 2 ligands had no impact on FXI activation by thrombin in the absence of polyP-70; however, in its presence, they attenuated activation by 40% to 65%. CONCLUSION PolyP-70 binds FXI and thrombin and promotes their interaction. Exosite 2 ligands attenuate activation because thrombin binds polyP-70 via exosite 2. Attenuation of FXI activation by exosite 1 ligands likely reflects allosteric modulation of exosite 2 and/or the active site of thrombin because exosite 1 is not directly involved in FXI activation. Therefore, allosteric modulation of thrombin's exosites may represent a novel strategy for downregulating FXI activation.
Collapse
|
2
|
PS. It was me all along! Emergence of phosphatidylserine in the procoagulant state in atrial fibrillation. Int J Cardiol 2018; 258:161-162. [DOI: 10.1016/j.ijcard.2018.02.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 02/07/2018] [Indexed: 11/23/2022]
|
3
|
Abstract
Platelets play a vital role in normal hemostasis to stem blood loss at sites of vascular injury by tethering and adhering to sites of injury, recruiting other platelets and blood cells to the developing clot, releasing vasoactive small molecules and proteins, and assembling and activating plasma coagulation proteins in a tightly regulated temporal and spatial manner. In synchrony with specific end products of coagulation, primarily cross-linked fibrin, a stable thrombus quickly forms. Far beyond physiological hemostasis and pathological thrombosis, emerging evidence supports platelets playing a pivotal role in vascular homeostasis, inflammation, cellular repair, regeneration, and wide range of autocrine and paracrine functions. In essence, platelets play both structural and functional roles as reporters, messengers, and active transporters surveying the vasculature for cues of environmental or developmental stimuli and participating as first responders.1 In this review, we will provide a contemporary perspective of platelet physiology, including fundamental, translational, and clinical constructs that apply directly to human health and disease.
Collapse
Affiliation(s)
- Richard C Becker
- From the Heart, Lung and Vascular Institute, University of Cincinnati College of Medicine, OH (R.C.B.); and Gill Heart and Vascular Institute (T.S., S.S.S.) and Lexington VA Medical Center (T.S., S.S.S.), University of Kentucky School of Medicine.
| | - Travis Sexton
- From the Heart, Lung and Vascular Institute, University of Cincinnati College of Medicine, OH (R.C.B.); and Gill Heart and Vascular Institute (T.S., S.S.S.) and Lexington VA Medical Center (T.S., S.S.S.), University of Kentucky School of Medicine
| | - Susan S Smyth
- From the Heart, Lung and Vascular Institute, University of Cincinnati College of Medicine, OH (R.C.B.); and Gill Heart and Vascular Institute (T.S., S.S.S.) and Lexington VA Medical Center (T.S., S.S.S.), University of Kentucky School of Medicine
| |
Collapse
|
4
|
Shiu HT, Leung PC, Ko CH. The roles of cellular and molecular components of a hematoma at early stage of bone healing. J Tissue Eng Regen Med 2018; 12:e1911-e1925. [PMID: 29207216 DOI: 10.1002/term.2622] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 10/23/2017] [Accepted: 11/22/2017] [Indexed: 12/14/2022]
Abstract
Bone healing is a complex repair process that commences with the formation of a blood clot at the injured bone, termed hematoma. It has evidenced that a lack of a stable hematoma causes delayed bone healing or non-union. The hematoma at the injured bone constitutes the early healing microenvironment. It appears to dictate healing pathways that ends in a regenerative bone. However, the hematoma is often clinically removed from the damaged site. Conversely, blood-derived products have been used in bone tissue engineering for treating critical sized defects, including fibrin gels and platelet-rich plasma. A second generation of platelet concentrate that is based on leukocyte and fibrin content has also been developed and introduced in market. Conflicting effect of these products in bone repair are reported. We propose that the bone healing response becomes dysregulated if the blood response and subsequent formation and properties of a hematoma are altered. This review focuses on the central structural, cellular, and molecular components of a fracture hematoma, with a major emphasis on their roles in regulating bone healing mechanism, and their interactions with mesenchymal stem cells. New angles towards a better understanding of these factors and relevant mechanisms involved at the beginning of bone healing may help to clarify limited or adverse effects of blood-derived products on bone repair. We emphasize that the recreation of an early hematoma niche with critical compositions might emerge as a viable therapeutic strategy for enhanced skeletal tissue engineering.
Collapse
Affiliation(s)
- Hoi Ting Shiu
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.,State Key Laboratory of Phytochemistry & Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Ping Chung Leung
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.,State Key Laboratory of Phytochemistry & Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Chun Hay Ko
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.,State Key Laboratory of Phytochemistry & Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| |
Collapse
|
5
|
Polyphosphate/platelet factor 4 complexes can mediate heparin-independent platelet activation in heparin-induced thrombocytopenia. Blood Adv 2016; 1:62-74. [PMID: 29296696 DOI: 10.1182/bloodadvances.2016000877] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 10/03/2016] [Indexed: 01/01/2023] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is a thrombotic disorder initiated by antibodies to complexes between platelet factor 4 (PF4) and heparin. The risk of recurrent thromboembolism persists after heparin is cleared and platelet activation leading to release of PF4 has dissipated. We asked whether antigenic complexes between polyphosphates and PF4 released from activated platelets might intensify or sustain the prothrombotic phenotype of HIT. PF4 forms stable, ultralarge complexes with polyphosphates of various sizes, including those released from platelets, which are recognized by the HIT-like monoclonal KKO, an immunoglobulin G2bκ monoclonal heparin/PF4 binding antibody, and by human HIT antibodies. KKO helps to protect PF4/polyphosphate complexes from degradation by phosphatases. Complement is activated when HIT antibodies bind to PF4/polyphosphate complexes and PF4 reverses the inhibition of complement by polyphosphates. Polyphosphates and PF4 are stored primarily in separate granules in resting platelets, but they colocalize when the cells are activated. Platelets activated by subaggregating doses of thrombin receptor activating peptide release polyphosphates and PF4, which form antigenic complexes that allow KKO to further activate platelets in the absence of heparin and exogenous PF4. These studies suggest that thrombin- or immune complex-mediated release of endogenous antigenic PF4/polyphosphate complexes from platelets may augment the prothrombotic risk of HIT and perpetuate the risk of thrombosis after heparin has been discontinued.
Collapse
|
6
|
Kulakovskaya TV, Lichko LP, Ryazanova LP. Diversity of phosphorus reserves in microorganisms. BIOCHEMISTRY (MOSCOW) 2015; 79:1602-14. [PMID: 25749167 DOI: 10.1134/s0006297914130100] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Phosphorus compounds are indispensable components of the Earth's biomass metabolized by all living organisms. Under excess of phosphorus compounds in the environment, microorganisms accumulate reserve phosphorus compounds that are used under phosphorus limitation. These compounds vary in their structure and also perform structural and regulatory functions in microbial cells. The most common phosphorus reserve in microorganism is inorganic polyphosphates, but in some archae and bacteria insoluble magnesium phosphate plays this role. Some yeasts produce phosphomannan as a phosphorus reserve. This review covers also other topics, i.e. accumulation of phosphorus reserves under nutrient limitation, phosphorus reserves in activated sludge, mycorrhiza, and the role of mineral phosphorus compounds in mammals.
Collapse
Affiliation(s)
- T V Kulakovskaya
- Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
| | | | | |
Collapse
|
7
|
Impact of extracellular RNA on endothelial barrier function. Cell Tissue Res 2014; 355:635-45. [DOI: 10.1007/s00441-014-1850-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 02/13/2014] [Indexed: 11/25/2022]
|
8
|
Shiu HT, Goss B, Lutton C, Crawford R, Xiao Y. Controlling whole blood activation and resultant clot properties by carboxyl and alkyl functional groups on material surfaces: a possible therapeutic approach for enhancing bone healing. J Mater Chem B 2014; 2:3009-3021. [DOI: 10.1039/c4tb00009a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Most research virtually ignores the important role of a blood clot in supporting bone healing.
Collapse
Affiliation(s)
- Hoi Ting Shiu
- Bone and Tissue Engineering
- Institute of Health and Biomedical Innovation
- Queensland University of Technology
- Brisbane, Australia
| | - Ben Goss
- Bone and Tissue Engineering
- Institute of Health and Biomedical Innovation
- Queensland University of Technology
- Brisbane, Australia
| | - Cameron Lutton
- Bone and Tissue Engineering
- Institute of Health and Biomedical Innovation
- Queensland University of Technology
- Brisbane, Australia
| | - Ross Crawford
- Bone and Tissue Engineering
- Institute of Health and Biomedical Innovation
- Queensland University of Technology
- Brisbane, Australia
| | - Yin Xiao
- Bone and Tissue Engineering
- Institute of Health and Biomedical Innovation
- Queensland University of Technology
- Brisbane, Australia
| |
Collapse
|
9
|
Abstract
Polyphosphate, synthesized by all cells, is a linear polymer of inorganic phosphate. When released into the circulation, it exerts prothrombotic and proinflammatory activities by modulating steps in the coagulation cascade. We examined the role of polyphosphate in regulating the evolutionarily related proteolytic cascade complement. In erythrocyte lysis assays, polyphosphate comprising more than 1000 phosphate units suppressed total hemolytic activity with a concentration to reduce maximal lysis to 50% that was 10-fold lower than with monophosphate. In the ion- and enzyme-independent terminal pathway complement assay, polyphosphate suppressed complement in a concentration- and size-dependent manner. Phosphatase-treated polyphosphate lost its ability to suppress complement, confirming that polymer integrity is required. Sequential addition of polyphosphate to the terminal pathway assay showed that polyphosphate interferes with complement only when added before formation of the C5b-7 complex. Physicochemical analyses using native gels, gel filtration, and differential scanning fluorimetry revealed that polyphosphate binds to and destabilizes C5b,6, thereby reducing the capacity of the membrane attack complex to bind to and lyse the target cell. In summary, we have added another function to polyphosphate in blood, demonstrating that it dampens the innate immune response by suppressing complement. These findings further establish the complex relationship between coagulation and innate immunity.
Collapse
|
10
|
Gomes FM, Ramos IB, Wendt C, Girard-Dias W, De Souza W, Machado EA, Miranda K. New insights into the in situ microscopic visualization and quantification of inorganic polyphosphate stores by 4',6-diamidino-2-phenylindole (DAPI)-staining. Eur J Histochem 2013; 57:e34. [PMID: 24441187 PMCID: PMC3896036 DOI: 10.4081/ejh.2013.e34] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 09/22/2013] [Accepted: 09/24/2013] [Indexed: 01/10/2023] Open
Abstract
Inorganic polyphosphate (PolyP) is a biological polymer that plays important roles in the cell physiology of both prokaryotic and eukaryotic organisms. Among the available methods for PolyP localization and quantification, a 4',6-diamidino-2-phenylindole(DAPI)-based assay has been used for visualization of PolyP-rich organelles. Due to differences in DAPI permeability to different compartments and/or PolyP retention after fixation, a general protocol for DAPI-PolyP staining has not yet been established. Here, we tested different protocols for DAPI-PolyP detection in a range of samples with different levels of DAPI permeability, including subcellular fractions, free-living cells and cryosections of fixed tissues. Subcellular fractions of PolyP-rich organelles yielded DAPI-PolyP fluorescence, although those with a complex external layer usually required longer incubation times, previous aldehyde fixation and/or detergent permeabilization. DAPI-PolyP was also detected in cryosections of OCT-embedded tissues analyzed by multi-photon microscopy. In addition, a semi-quantitative fluorimetric analysis of DAPI-stained fractions showed PolyP mobilization in a similar fashion to what has been demonstrated with the use of enzyme-based quantitative protocols. Taken together, our results support the use of DAPI for both PolyP visualization and quantification, although specific steps are suggested as a general guideline for DAPI-PolyP staining in biological samples with different degrees of DAPI and PolyP permeability.
Collapse
Affiliation(s)
- F M Gomes
- Universidade Federal do Rio de Janeiro.
| | | | | | | | | | | | | |
Collapse
|
11
|
Gomes FM, Carvalho DB, Peron AC, Saito K, Miranda K, Machado EA. Inorganic polyphosphates are stored in spherites within the midgut of Anticarsia gemmatalis and play a role in copper detoxification. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:211-219. [PMID: 21946413 DOI: 10.1016/j.jinsphys.2011.09.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 09/13/2011] [Accepted: 09/13/2011] [Indexed: 05/31/2023]
Abstract
Inorganic polyphosphates (PolyP) are widespread molecules that have been shown to play a role in metal detoxification and heavy-metal tolerance. In the present report, we investigated the functional role of spherites as PolyP-metal binding stores in epithelial cells of the midgut of Anticarsia gemmatalis, a lepidopteran pest of soybean. PolyP stores were detected by DAPI staining and indirect immunohistochemistry as vesicles distributed in columnar cells and around goblet cell cavities. These PolyP vesicles were identified as spherites by their elemental profile in cell lysates that were partially modulated by P- or V-ATPases. PolyP levels along the midgut were detected using a recombinant exopolyphosphatase assay. When copper was added in the diet of larva, copper detection in spherites by X-ray microanalysis correlated with an increase in the relative phosphorous X-ray signal and with an increase in PolyP levels in epithelia cell lysate. Transmission electron microscopy of chemically fixed or cryofixed and freeze substituted tissues confirmed a preferential localization of spherites around the goblet cell cavity. Taken together, these results suggest that spherites store high levels of PolyP that are modulated during metal uptake and detoxification. The similarity between PolyP granules and spherites herein described also suggest that PolyP is one of the main phosphorous source of spherites found in different biological models. This suggests physiological roles played by spherites in the midgut of arthropods and mechanisms involved in heavy metal resistance among different insect genera.
Collapse
Affiliation(s)
- F M Gomes
- Laboratório de Entomologia Médica, Programa de Biologia Celular e Parasitologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil
| | | | | | | | | | | |
Collapse
|
12
|
Kulakovskaya TV, Vagabov VM, Kulaev IS. Inorganic polyphosphate in industry, agriculture and medicine: Modern state and outlook. Process Biochem 2012. [DOI: 10.1016/j.procbio.2011.10.028] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
13
|
The procoagulant and proinflammatory plasma contact system. Semin Immunopathol 2011; 34:31-41. [DOI: 10.1007/s00281-011-0288-2] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 07/20/2011] [Indexed: 10/17/2022]
|