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Zheng Z, Mukhametova L, Boffa MB, Moore EE, Wolberg AS, Urano T, Kim PY. Assays to quantify fibrinolysis: strengths and limitations. Communication from the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee on fibrinolysis. J Thromb Haemost 2023; 21:1043-1054. [PMID: 36759279 PMCID: PMC10109242 DOI: 10.1016/j.jtha.2023.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 01/04/2023] [Accepted: 01/06/2023] [Indexed: 01/15/2023]
Abstract
Fibrinolysis is a series of enzymatic reactions that degrade insoluble fibrin. Plasminogen activators convert the zymogen plasminogen to the active serine protease plasmin, which cleaves and solubilizes crosslinked fibrin clots into fibrin degradation products. The quantity and quality of fibrinolytic enzymes, their respective inhibitors, and clot structure determine overall fibrinolysis. The quantity of protein can be measured by antigen-based assays, and both quantity and quality can be assessed using functional assays. Furthermore, variations of commonly used assays have been reported, which are tailored to address the role(s) of specific fibrinolytic factors and cellular elements (eg, platelets, neutrophils, and red blood cells). Although the concentration and/or activity of a protein can be quantified, how these individual components contribute to the overall fibrinolysis outcome can be challenging to determine. This difficulty is due to temporal changes within and around the thrombi during the clot breakdown, particularly the fibrin matrix structure, and composition. Furthermore, terms such as "fibrinolytic activity/potential," "plasminogen activation," and "plasmin activity" are often used interchangeably despite having different definitions. The purpose of this review is to 1) summarize the assays measuring fibrinolysis activity and potential, 2) facilitate the interpretation of data generated by these assays, and 3) summarize the strengths and limitations of these assays.
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Affiliation(s)
- Ze Zheng
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA; Blood Research Institute, Versiti Blood Center of Wisconsin, Milwaukee, Wisconsin, USA
| | - Liliya Mukhametova
- Chemical Enzymology Department, Chemistry Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Michael B Boffa
- Department of Biochemistry and Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Ernest E Moore
- Department of Surgery, Ernest E. Moore Shock Trauma Center at Denver Health, University of Colorado, Denver, Colorado, USA
| | - Alisa S Wolberg
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Tetsumei Urano
- Department of Medical Physiology, Hamamatsu University School of Medicine and Shizuoka Graduate University of Public Health, Hamamatsu, Japan
| | - Paul Y Kim
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada; Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada.
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Kuleš J, Bilić P, Horvatić A, Kovačević A, Guillemin N, Ljubić BB, Galan A, Jović I, Torti M, Rubić I, Eckersall PD, Mrljak V. Serum proteome profiling in canine chronic valve disease using a TMT-based quantitative proteomics approach. J Proteomics 2020; 223:103825. [PMID: 32422277 DOI: 10.1016/j.jprot.2020.103825] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/09/2020] [Accepted: 05/12/2020] [Indexed: 10/24/2022]
Abstract
Chronic valve disease (CVD) is the most common clinically significant heart disease of dogs, affecting 20 to 40% of dogs. The aim of this study was to evaluate the serum protein profile of healthy and CVD affected dogs, by means of an isobaric tandem mass tag (TMT) label-based high-resolution quantitative proteomic approach. Additionally, conventional cardiac biomarkers were measured in the serum, functional bioinformatics analysis was employed for elucidating molecular mechanisms and pathways associated with CVD, and validation of proteomic results was performed by immunoassays and Western blotting. Of 290 identified and quantified proteins, 15 proteins showed significantly different abundances (p < .05), including antithrombin-III, alpha-2-antiplasmin, tetranectin, apolipoprotein M, adiponectin, inter-alpha-trypsin inhibitor heavy chain H1, gelsolin and apolipoprotein B-100. The identified proteins with differently abundances are involved in a number of pathways, such as complement and coagulation cascades, haemostasis, regulation of actin cytoskeleton, lipid metabolism and transport. We found comparative similarities with human disease in terms of identified proteins and GO pathways, which confirmed similar pathophysiology of this disease, but also differences, mainly in lipid metabolism. SIGNIFICANCE: There have been few investigations of canine serum proteome despite the potential for biomarker discovery and comparative disease analysis. Establishing serum proteomic signatures in healthy dogs and dogs with CVD will benefit for understanding the aetiology of disease in dogs, identify putative biomarkers and provide models of comparative human disease. Circulating biomarkers are important for understanding of the mechanisms of cardiovascular disease and high incidence of CVD in dogs prioritizes the search for novel biomarkers.
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Affiliation(s)
- Josipa Kuleš
- Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia
| | - Petra Bilić
- Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia
| | - Anita Horvatić
- Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia
| | - Alan Kovačević
- Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Switzerland
| | - Nicolas Guillemin
- Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia
| | - Blanka Beer Ljubić
- Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia
| | - Asier Galan
- Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia
| | - Ines Jović
- Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia
| | - Marin Torti
- Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia
| | - Ivana Rubić
- Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia
| | - Peter David Eckersall
- College of Veterinary, Medical and Life sciences, School of Veterinary Medicine, University of Glasgow, UK
| | - Vladimir Mrljak
- Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia.
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The plasma proteome and the acute phase protein response in canine pyometra. J Proteomics 2020; 223:103817. [PMID: 32416315 DOI: 10.1016/j.jprot.2020.103817] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/24/2020] [Accepted: 05/09/2020] [Indexed: 01/30/2023]
Abstract
Canine pyometra is a common inflammatory disease of uterus in sexually mature bitches caused by secondary bacterial infection, leading to change in plasma proteins associated with the innate immune system. Proteomic investigation is increasingly being applied to canine diseases in order to identify and quantify significant changes in the plasma proteome. The aim of the study was to assess and quantify changes in plasma proteome profiles of healthy dogs and pyometra affected bitches using a TMT-based high-resolution quantitative proteomic approach. As a result, 22 proteins were significantly down-regulated including transthyretin, antithrombin, retinol-binding protein, vitamin D binding protein, paraoxonase 1, and kallikrein, while 16 were significantly up-regulated including haptoglobin light chain, alpha-1-acid glycoprotein, C-reactive protein precursor, and lipopolysaccharide-binding protein in dogs with pyometra. Pathway analysis indicated that acute inflammatory response, regulation of body fluid levels, protein activation cascade, the humoral immune response, and phagocytosis were affected in pyometra. Validation of biological relevance of the proteomic study was evident with significant increases in the concentrations of haptoglobin, C-reactive protein, alpha-1-acid glycoprotein, and ceruloplasmin by immunoassay. Pyometra in bitches was shown to stimulate an increase in host defence system proteins in response to inflammatory disease including the acute phase proteins. SIGNIFICANCE: The label-based high-resolution quantitative proteomics analysis and bioinformatic approach used in this study provide insight into the complex pathophysiology of inflammation associated with pyometra revealing proteins with biomarker potential. Early diagnosis and therapeutic intervention may prevent severe complications associated with advancing sepsis in dogs with pyometra. Therefore the identification of diagnostic biomarkers that, after clinical validation may be used in veterinary practice and protein relevant to pathways responding to disease are important findings of the study. Data are available via ProteomeXchange with identifier PXD015951.
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Eltringham-Smith LJ, Bhakta V, Gataiance S, Sheffield WP. Reduction of thrombus size in murine models of thrombosis following administration of recombinant α1-proteinase inhibitor mutant proteins. Thromb Haemost 2017; 107:972-84. [DOI: 10.1160/th11-09-0604] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 02/02/2012] [Indexed: 11/05/2022]
Abstract
SummaryThe variant serpin α1-PI M358R inhibits thrombin and other proteases such as activated protein C (APC) and factor XIa. We previously described recombinant proteins HAPI M358R (α1-PI M358R containing an N-terminal extension corresponding to residues 1–75 of heparin cofactor II) and HAPI RCL5 (HAPI M358R with F352-I356 and I360 substituted for the corresponding residues of antithrombin), with enhanced selectivity for thrombin over APC inhibition. We tested the hypotheses that these recombinant proteins would limit thrombosis in three mouse models, and that the HAPI chimeric proteins would be more effective than α1-PI M358R. Recombinant serpins were purified from Escherichia coli by nickel chelate and ion exchange affinity chromatography, and administered to mice intravenously. HAPI RCL5 reduced incorporation of radiolabelled fibrin(ogen) into thrombi in the ferric chloride-injured vena cava in a dose-dependent manner; HAPI M358R was less effective and α1-PI M358R was without effect. In a model of murine endotoxaemia, HAPI RCL5 was more effective than α1-PI M358R in reducing radiolabelled fibrin(ogen) deposition in heart and kidneys; immunohis-tochemistry of tissue sections showed lesser staining with anti-fibrin(ogen) antibodies with both treatments. In the ferric chloride-injured murine carotid artery, administration of both recombinant serpins was equally effective in lengthening the vessel’s time to occlusion. Our results show that the antithrombotic efficacy of the recombinant serpins correlates with their potency as thrombin inhibitors, since HAPI RCL5 inhibits thrombin, but not factors Xa, XIa, XIIa, or neutrophil elastase, more rapidly than α1-PI M358R.
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Reed GL, Houng AK, Singh S, Wang D. α2-Antiplasmin: New Insights and Opportunities for Ischemic Stroke. Semin Thromb Hemost 2016; 43:191-199. [PMID: 27472428 DOI: 10.1055/s-0036-1585077] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Thrombotic vascular occlusion is the leading cause of ischemic stroke. High blood levels of α2-antiplasmin (a2AP), an ultrafast, covalent inhibitor of plasmin, have been linked in humans to increased risk of ischemic stroke and failure of tissue plasminogen activator (tPA) therapy. Consistent with these observations, a2AP neutralizes the therapeutic benefit of tPA therapy in experimental stroke. In addition, a2AP has deleterious, dose-related effects on ischemic brain injury in the absence of therapy. Experimental therapeutic inactivation of a2AP markedly reduces microvascular thrombosis, ischemic brain injury, brain swelling, brain hemorrhage, and death after thromboembolic stroke. These data provide new insights into the critical importance of a2AP in the pathogenesis of ischemic brain injury and suggest that transiently inactivating a2AP may have therapeutic value in ischemic stroke.
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Affiliation(s)
- Guy L Reed
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, Tennessee
| | - Aiilyan K Houng
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, Tennessee
| | - Satish Singh
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, Tennessee
| | - Dong Wang
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, Tennessee
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Kuleš J, Mrljak V, Barić Rafaj R, Selanec J, Burchmore R, Eckersall PD. Identification of serum biomarkers in dogs naturally infected with Babesia canis canis using a proteomic approach. BMC Vet Res 2014; 10:111. [PMID: 24885808 PMCID: PMC4045879 DOI: 10.1186/1746-6148-10-111] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 04/07/2014] [Indexed: 11/30/2022] Open
Abstract
Background Canine babesiosis is a tick-borne disease that is caused by the haemoprotozoan parasites of the genus Babesia. There are limited data on serum proteomics in dogs, and none of the effect of babesiosis on the serum proteome. The aim of this study was to identify the potential serum biomarkers of babesiosis using proteomic techniques in order to increase our understanding about disease pathogenesis. Results Serum samples were collected from 25 dogs of various breeds and sex with naturally occurring babesiosis caused by B. canis canis. Blood was collected on the day of admission (day 0), and subsequently on the 1st and 6th day of treatment. Two-dimensional electrophoresis (2DE) of pooled serum samples of dogs with naturally occurring babesiosis (day 0, day 1 and day 6) and healthy dogs were run in triplicate. 2DE image analysis showed 64 differentially expressed spots with p ≤ 0.05 and 49 spots with fold change ≥2. Six selected spots were excised manually and subjected to trypsin digest prior to identification by electrospray ionisation mass spectrometry on an Amazon ion trap tandem mass spectrometry (MS/MS). Mass spectrometry data was processed using Data Analysis software and the automated Matrix Science Mascot Daemon server. Protein identifications were assigned using the Mascot search engine to interrogate protein sequences in the NCBI Genbank database. A number of differentially expressed serum proteins involved in inflammation mediated acute phase response, complement and coagulation cascades, apolipoproteins and vitamin D metabolism pathway were identified in dogs with babesiosis. Conclusions Our findings confirmed two dominant pathogenic mechanisms of babesiosis, haemolysis and acute phase response. These results may provide possible serum biomarker candidates for clinical monitoring of babesiosis and this study could serve as the basis for further proteomic investigations in canine babesiosis.
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Affiliation(s)
| | | | | | | | | | - Peter D Eckersall
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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Sheffield WP, Eltringham-Smith LJ. Incorporation of albumin fusion proteins into fibrin clots in vitro and in vivo: comparison of different fusion motifs recognized by factor XIIIa. BMC Biotechnol 2011; 11:127. [PMID: 22185689 PMCID: PMC3258216 DOI: 10.1186/1472-6750-11-127] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 12/20/2011] [Indexed: 01/05/2023] Open
Abstract
Background The transglutaminase activated factor XIII (FXIIIa) acts to strengthen pathological fibrin clots and to slow their dissolution, in part by crosslinking active α2-antiplasmin (α2AP) to fibrin. We previously reported that a yeast-derived recombinant fusion protein comprising α2AP residues 13-42 linked to human serum albumin (HSA) weakened in vitro clots but failed to become specifically incorporated into in vivo clots. In this study, our aims were to improve both the stability and clot localization of the HSA fusion protein by replacing α2AP residues 13-42 with shorter sequences recognized more effectively by FXIIIa. Results Expression plasmids were prepared encoding recombinant HSA with the following N-terminal 23 residue extensions: H6NQEQVSPLTLLAG4Y (designated XL1); H6DQMMLPWAVTLG4Y (XL2); H6WQHKIDLPYNGAG4Y (XL3); and their 17 residue non-His-tagged equivalents (XL4, XL5, and XL6). The HSA moiety of XL4- to XL6-HSA proteins was C-terminally His-tagged. All chimerae were efficiently secreted from transformed Pichia pastoris yeast except XL3-HSA, and following nickel chelate affinity purification were found to be intact by amino acid sequencing, as was an N-terminally His-tagged version of α2AP(13-42)-HSA. Of the proteins tested, XL5-HSA was cross-linked to biotin pentylamine (BPA) most rapidly by FXIIIa, and was the most effective competitor of α2AP crosslinking not only to BPA but also to plasma fibrin clots. In the mouse ferric chloride vena cava thrombosis model, radiolabeled XL5-HSA was retained in the clot to a greater extent than recombinant HSA. In the rabbit jugular vein stasis thrombosis model, XL5-HSA was also retained in the clot, in a urea-insensitive manner indicative of crosslinking to fibrin, to a greater extent than recombinant HSA. Conclusions Fusion protein XL5-HSA (DQMMLPWAVTLG4Y-HSAH6) was found to be more active as a substrate for FXIIIa-mediated transamidation than seven other candidate fusion proteins in vitro. The improved stability and reactivity of this chimeric protein was further evidenced by its incorporation into in vivo clots formed in thrombosis models in both mice and rabbits.
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Affiliation(s)
- William P Sheffield
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
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Tsurupa G, Yakovlev S, McKee P, Medved L. Noncovalent interaction of alpha(2)-antiplasmin with fibrin(ogen): localization of alpha(2)-antiplasmin-binding sites. Biochemistry 2010; 49:7643-51. [PMID: 20687529 DOI: 10.1021/bi1010317] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Covalent incorporation (cross-linking) of plasmin inhibitor alpha(2)-antiplasmin (alpha(2)-AP) into fibrin clots increases their resistance to fibrinolysis. We hypothesized that alpha(2)-AP may also interact noncovalently with fibrin prior to its covalent cross-linking. To test this hypothesis, we studied binding of alpha(2)-AP to fibrin(ogen) and its fragments by an enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance. The experiments revealed that alpha(2)-AP binds to polymeric fibrin and surface-adsorbed fibrin(ogen), while no binding was observed with fibrinogen in solution. To localize the alpha(2)-AP-binding sites, we studied the interaction of alpha(2)-AP with the fibrin(ogen)-derived D(1), D-D, and E(3) fragments, and the recombinant alphaC region and its constituents, alphaC connector and alphaC domain and its subdomains, which together encompass practically the whole fibrin(ogen) molecule. In the ELISA, alpha(2)-AP bound to immobilized D(1), D-D, alphaC region, alphaC domain, and its C-terminal subdomain. The binding was Lys-independent and was not inhibited by plasminogen or tPA. Furthermore, the affinity of alpha(2)-AP for D-D was significantly increased in the presence of plasminogen, while that to the alphaC domain remained unaffected. Altogether, these results indicate that the fibrin(ogen) D region and the C-terminal subdomain of the alphaC domain contain high-affinity alpha(2)-AP-binding sites that are cryptic in fibrinogen and exposed in fibrin or adsorbed fibrinogen, and the presence of plasminogen facilitates interaction of alpha(2)-AP with the D regions. The discovered noncovalent interaction of alpha(2)-AP with fibrin may contribute to regulation of the initial stage of fibrinolysis and provide proper orientation of the cross-linking sites to facilitate covalent cross-linking of alpha(2)-AP to the fibrin clot.
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Affiliation(s)
- Galina Tsurupa
- Center for Vascular and Inflammatory Diseases and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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Goettig P, Magdolen V, Brandstetter H. Natural and synthetic inhibitors of kallikrein-related peptidases (KLKs). Biochimie 2010; 92:1546-67. [PMID: 20615447 PMCID: PMC3014083 DOI: 10.1016/j.biochi.2010.06.022] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 06/29/2010] [Indexed: 01/21/2023]
Abstract
Including the true tissue kallikrein KLK1, kallikrein-related peptidases (KLKs) represent a family of fifteen mammalian serine proteases. While the physiological roles of several KLKs have been at least partially elucidated, their activation and regulation remain largely unclear. This obscurity may be related to the fact that a given KLK fulfills many different tasks in diverse fetal and adult tissues, and consequently, the timescale of some of their physiological actions varies significantly. To date, a variety of endogenous inhibitors that target distinct KLKs have been identified. Among them are the attenuating Zn(2+) ions, active site-directed proteinaceous inhibitors, such as serpins and the Kazal-type inhibitors, or the huge, unspecific compartment forming α(2)-macroglobulin. Failure of these inhibitory systems can lead to certain pathophysiological conditions. One of the most prominent examples is the Netherton syndrome, which is caused by dysfunctional domains of the Kazal-type inhibitor LEKTI-1 which fail to appropriately regulate KLKs in the skin. Small synthetic inhibitory compounds and natural polypeptidic exogenous inhibitors have been widely employed to characterize the activity and substrate specificity of KLKs and to further investigate their structures and biophysical properties. Overall, this knowledge leads not only to a better understanding of the physiological tasks of KLKs, but is also a strong fundament for the synthesis of small compound drugs and engineered biomolecules for pharmaceutical approaches. In several types of cancer, KLKs have been found to be overexpressed, which makes them clinically relevant biomarkers for prognosis and monitoring. Thus, down regulation of excessive KLK activity in cancer and in skin diseases by small inhibitor compounds may represent attractive therapeutical approaches.
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Affiliation(s)
- Peter Goettig
- Division of Structural Biology, Department of Molecular Biology, University of Salzburg, Billrothstrasse 11, 5020 Salzburg, Austria.
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Sheffield WP, Eltringham-Smith LJ, Gataiance S, Bhakta V. Addition of a sequence from alpha2-antiplasmin transforms human serum albumin into a blood clot component that speeds clot lysis. BMC Biotechnol 2009; 9:15. [PMID: 19257897 PMCID: PMC2654442 DOI: 10.1186/1472-6750-9-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Accepted: 03/03/2009] [Indexed: 11/21/2022] Open
Abstract
Background The plasma protein α2-antiplasmin (α2AP) is cross-linked to fibrin in blood clots by the transglutaminase factor XIIIa, and in that location retards clot lysis. Competition for this effect could be clinically useful in patients with thrombosis. We hypothesized that fusion of N-terminal portions of α2-antiplasmin to human serum albumin (HSA) and production of the chimeric proteins in Pichia pastoris yeast would produce a stable and effective competitor protein. Results Fusion protein α2AP(13-42)-HSA was efficiently secreted from transformed yeast and purified preparations contained within a mixed population the full-length intact form, while fusions with longer α2AP moieties were inefficiently secreted and/or degraded. The α2AP(13-42)-HSA protein, but not recombinant HSA, was cross-linked to both chemical lysine donors and fibrin or fibrinogen by factor XIIIa, although with less rapid kinetics than native α2AP. Excess α2AP(13-42)-HSA competed with α2AP for cross-linking to chemical lysine donors more effectively than a synthetic α2AP(13-42) peptide, and reduced the α2AP-dependent resistance to fibrinolysis of plasma clots equally effectively as the peptide. Native α2AP was found in in vivo clots in rabbits to a greater extent than α2AP(13-42), however. Conclusion In this first report of transfer of transglutamination substrate status from one plasma protein to another, fusion protein α2AP(13-42)-HSA was shown to satisfy initial requirements for a long-lasting, well-tolerated competitive inhibitor of α2-antiplasmin predicted to act in a clot-localized manner.
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Affiliation(s)
- William P Sheffield
- Department of Pathology and Molecular Medicine, McMaster University, 1200 Main Street West, Hamilton, Ontario, Canada.
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Wang H, Zhang Y, Heuckeroth RO. PAI-1 deficiency reduces liver fibrosis after bile duct ligation in mice through activation of tPA. FEBS Lett 2007; 581:3098-104. [PMID: 17561000 DOI: 10.1016/j.febslet.2007.05.049] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 05/08/2007] [Accepted: 05/18/2007] [Indexed: 11/19/2022]
Abstract
Plasminogen activator inhibitor-1 (PAI-1) increases injury in several liver, lung and kidney disease models. The objective of this investigation was to assess the effect of PAI-1 deficiency on cholestatic liver fibrosis and determine PAI-1 influenced fibrogenic mechanisms. We found that PAI-1(-/-) mice had less fibrosis than wild type (WT) mice after bile duct ligation. This change correlated with increased tissue-type plasminogen activator (tPA) activity, and increased matrix metalloproteinase-9 (MMP-9), but not MMP-2 activity. Furthermore, there was increased activation of the tPA substrate hepatocyte growth factor (HGF), a known anti-fibrogenic protein. In contrast, there was no difference in hepatic urokinase plasminogen activator (uPA) or plasmin activities between PAI-1(-/-) and WT mice. There was also no difference in the level of transforming growth factor beta 1 (TGF-beta1), stellate cell activation or collagen production between WT and PAI-1(-/-) animals. In conclusion, PAI-1 deficiency reduces hepatic fibrosis after bile duct obstruction mainly through the activation of tPA and HGF.
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Affiliation(s)
- Hongtao Wang
- Division of Gastroenterology and Nutrition, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
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