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The Journal of Clinical Investigation Apr 2020BACKGROUNDHBV-related acute-on-chronic liver failure (HBV-ACLF) is hallmarked by high short-term mortality rates, calling for accurate prognostic biomarkers for initial... (Clinical Trial)
Clinical Trial
BACKGROUNDHBV-related acute-on-chronic liver failure (HBV-ACLF) is hallmarked by high short-term mortality rates, calling for accurate prognostic biomarkers for initial risk stratification.METHODSThree tandem mass tag-labeled (TMT-labeled) quantitative proteomic studies were performed on 10 patients with HBV-related acute hepatic decompensation and on 20 patients with HBV-ACLF. Candidate biomarkers were preliminarily verified in a cross-sectional cohort (n = 144) and further confirmed in 2 prospective cohorts (n = 207 and n = 148).RESULTSPlasminogen, a potential prognostic biomarker for HBV-ACLF, was identified by TMT quantitative proteomics and preliminarily verified in the cross-sectional cohort. Further validation with a prospective cohort (n = 207) showed that plasminogen levels at admission were significantly lower (P < 0.001) in HBV-ACLF nonsurvivors than in survivors. The cumulative survival duration of patients with high plasminogen levels was significantly longer (P < 0.001) than that of patients with low plasminogen levels. During hospitalization, plasminogen levels significantly decreased (P = 0.008) in the deterioration group but significantly increased (P < 0.001) in the improvement group. Additionally, plasminogen levels gradually increased in survivors but gradually decreased in nonsurvivors. The P5 score, a prognostic panel incorporating plasminogen levels, hepatic encephalopathy occurrence, age, international normalized ratio (INR), and total bilirubin, was significantly superior to the Child-Pugh, Model for End-stage Liver Disease (MELD), Chronic Liver Failure Consortium ACLF (CLIF-C ACLF), Chinese Group on the Study of Severe Hepatitis B (COSSH), and HINT (a prognostic score based on hepatic encephalopathy occurrence, INR, neutrophil count, and thyroid-stimulating hormone) scores (all P < 0.05). The performances of the plasminogen level and P5 score were validated in a second multicenter, prospective cohort (n = 148).CONCLUSIONSPlasminogen is a promising prognostic biomarker for HBV-ACLF, and sequential plasminogen measurements could profile the clinical course of HBV-ACLF. P5 is a high-performance prognostic score for HBV-ACLF.FUNDINGThe National Key Research and Development Program (2017YFC1200204); the National Natural Science Foundation of China (81400589, 81600497); the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (81121002); the Chinese High-Tech Research and Development Programs (2012AA020204); the National S&T Major Project (2012ZX10002004); and the Zhejiang Provincial Medicine and Health Science and Technology Project (2016147735).
Topics: Acute-On-Chronic Liver Failure; Adult; Biomarkers; Female; Hepatitis B virus; Hepatitis B, Chronic; Humans; Male; Middle Aged; Plasminogen
PubMed: 32175919
DOI: 10.1172/JCI130197 -
Journal of Thrombosis and Haemostasis :... Oct 2023The plasminogen/plasmin (Plg/Pla) system, best known for its classical role in thrombolysis, has been recently highlighted as a regulator of other biological processes... (Review)
Review
The plasminogen/plasmin (Plg/Pla) system, best known for its classical role in thrombolysis, has been recently highlighted as a regulator of other biological processes in mammals, including key steps involved in the resolution of inflammation. Inflammation resolution is a complex process coordinated by different cellular effectors, notably leukocytes, and active mediators, and is initiated shortly after the inflammatory response begins. Once the inflammatory insult is eliminated, an effective and timely engagement of proresolution programs prevents persistent inflammation, thereby avoiding excessive tissue damage, fibrosis, and the development of autoimmunity. Interestingly, recent studies demonstrate that Plg/Pla and their receptor, plasminogen receptor (Plg-R), regulate key steps in inflammation resolution. The number of studies investigating the involvement of the Plg/Pla system in these and other aspects of inflammation, including degradation of extracellular matrices, immune cell migration, wound healing, and skeletal growth and maintenance, highlights key roles of the Plg/Pla system during physiological and pathologic conditions. Here, we discuss robust evidence in the literature for the emerging roles of the Plg/Pla system in key steps of inflammation resolution. These findings suggest that dysregulation in Plg production and its activation plays a role in the pathogenesis of inflammatory diseases. Elucidating central mechanisms underlying the role of Plg/Pla in key steps of inflammation resolution either in preclinical models of inflammation or in human inflammatory conditions, can provide a rationale for the development of new pharmacologic interventions to promote resolution of inflammation, and open new pathways for the treatment of thromboinflammatory conditions.
Topics: Animals; Humans; Plasminogen; Fibrinolysin; Macrophages; Inflammation; Fibrinolysis; Mammals
PubMed: 37495082
DOI: 10.1016/j.jtha.2023.07.013 -
Atherosclerosis May 2022Elevated plasma concentrations of lipoprotein(a) (Lp(a)) are a causal risk factor for the development of atherothrombotic disorders including coronary heart disease.... (Review)
Review
Elevated plasma concentrations of lipoprotein(a) (Lp(a)) are a causal risk factor for the development of atherothrombotic disorders including coronary heart disease. However, the pathological mechanisms underlying this causal relationship remain incompletely defined. Lp(a) consists of a lipoprotein particle in which apolipoproteinB100 is covalently linked to the unique glycoprotein apolipoprotein(a) (apo(a)). The remarkable homology between apo(a) and the fibrinolytic proenzyme plasminogen strongly suggests an antifibrinolytic role: apo(a) contains a strong lysine binding site and can block the sites on fibrin and cellular receptors required for plasminogen activation, but itself lacks proteolytic activity. While numerous in vitro and animal model studies indicate that apo(a) can inhibit plasminogen activation and fibrinolysis, this activity may not be preserved in Lp(a). Moreover, elevated Lp(a) does not reduce the efficacy of thrombolytic therapy and is not a risk factor for some non-atherosclerotic thrombotic disorders such as venous thromboembolism. Accordingly, different prothrombotic mechanisms for Lp(a) must be contemplated. Evidence exists that Lp(a) binds to and inactivates tissue factor pathway inhibitor and stimulates expression of tissue factor by monocytes. Moreover, some studies have shown that Lp(a) promotes platelet activation and aggregation, at least in response to some agonists. Lp(a) alters the structure of the fibrin network to make it less permeable and more resistant to lysis. Finally, Lp(a) may promote the development of a vulnerable plaque phenotype that is more prone to rupture and hence the precipitation of atherothrombotic events. Further study, especially in animal models of thrombosis, is required to clarify the prothrombotic effects of Lp(a).
Topics: Animals; Apolipoproteins A; Apoprotein(a); Fibrin; Fibrinolysis; Lipoprotein(a); Plasminogen; Thrombosis
PubMed: 35606079
DOI: 10.1016/j.atherosclerosis.2022.04.009 -
Arteriosclerosis, Thrombosis, and... Oct 2023High levels of Lp(a) (lipoprotein(a)) are associated with multiple forms of cardiovascular disease. Lp(a) consists of an apoB-containing particle attached to the...
BACKGROUND
High levels of Lp(a) (lipoprotein(a)) are associated with multiple forms of cardiovascular disease. Lp(a) consists of an apoB-containing particle attached to the plasminogen homologue apo(a). The pathways for Lp(a) clearance are not well understood. We previously discovered that the plasminogen receptor PlgRKT (plasminogen receptor with a C-terminal lysine) promoted Lp(a) uptake in liver cells. Here, we aimed to further define the role of PlgRKT and to investigate the role of 2 other plasminogen receptors, annexin A2 and S100A10 (S100 calcium-binding protein A10) in the endocytosis of Lp(a).
METHODS
Human hepatocellular carcinoma (HepG2) cells and haploid human fibroblast-like (HAP1) cells were used for overexpression and knockout of plasminogen receptors. The uptake of Lp(a), LDL (low-density lipoprotein), apo(a), and endocytic cargos was visualized and quantified by confocal microscopy and Western blotting.
RESULTS
The uptake of both Lp(a) and apo(a), but not LDL, was significantly increased in HepG2 and HAP1 cells overexpressing PlgRKT, annexin A2, or S100A10. Conversely, Lp(a) and apo(a), but not LDL, uptake was significantly reduced in HAP1 cells in which PlgRKT and S100A10 were knocked out. Surface binding studies in HepG2 cells showed that overexpression of PlgRKT, but not annexin A2 or S100A10, increased Lp(a) and apo(a) plasma membrane binding. Annexin A2 and S100A10, on the other hand, appeared to regulate macropinocytosis with both proteins significantly increasing the uptake of the macropinocytosis marker dextran when overexpressed in HepG2 and HAP1 cells and knockout of S100A10 significantly reducing dextran uptake. Bringing these observations together, we tested the effect of a PI3K (phosphoinositide-3-kinase) inhibitor, known to inhibit macropinocytosis, on Lp(a) uptake. Results showed a concentration-dependent reduction confirming that Lp(a) uptake was indeed mediated by macropinocytosis.
CONCLUSIONS
These findings uncover a novel pathway for Lp(a) endocytosis involving multiple plasminogen receptors that enhance surface binding and stimulate macropinocytosis of Lp(a). Although the findings were produced in cell culture models that have limitations, they could have clinical relevance since drugs that inhibit macropinocytosis are in clinical use, that is, the PI3K inhibitors for cancer therapy and some antidepressant compounds.
Topics: Humans; Plasminogen; Lipoprotein(a); Annexin A2; Dextrans; Phosphatidylinositol 3-Kinases; Carrier Proteins; Apolipoproteins A
PubMed: 37589135
DOI: 10.1161/ATVBAHA.123.319344 -
Haematologica Feb 2021Tissue plasminogen activator (tPA) and urokinase (uPA) differ in their modes of action. Efficient tPA-mediated plasminogen activation requires binding to fibrin. In...
Tissue plasminogen activator (tPA) and urokinase (uPA) differ in their modes of action. Efficient tPA-mediated plasminogen activation requires binding to fibrin. In contrast, uPA is fibrin independent and activates plasminogen in solution or when associated with its cellular receptor uPAR. We have previously shown that polyphosphate (polyP), alters fibrin structure and attenuates tPA and plasminogen binding to fibrin, thereby down-regulating fibrinolysis. Here we investigate the impact of polyP on uPA-mediated fibrinolysis. As previously reported polyP of an average chain length of 65 (polyP65) delays tPA-mediated fibrinolysis. The rate of plasmin generation was also delayed and reduced 1.6-fold in polyP65-containing clots (0.74 ± 0.06 vs. 1.17 ± 0.14 pM/s in P < 0.05). Analysis of tPA-mediated fibrinolysis in real-time by confocal microscopy was significantly slower in polyP65-containing clots. In marked contrast, polyP65 augmented the rate of uPA-mediated plasmin generation 4.7-fold (3.96 ± 0.34 vs. 0.84 ± 0.08 pM/s; P < 0.001) and accelerated fibrinolysis (t1/2 64.5 ± 1.7 min vs. 108.2 ± 3.8 min; P < 0.001). Analysis of lysis in real-time confirmed that polyP65 enhanced uPA-mediated fibrinolysis. Varying the plasminogen concentration (0.125 to 1 μM) in clots dose-dependently enhanced uPA-mediated fibrinolysis, while negligible changes were observed on tPA-mediated fibrinolysis. The accelerating effect of polyP65 on uPA-mediated fibrinolysis was overcome by additional plasminogen, while the down-regulation of tPA-mediated lysis and plasmin generation was largely unaffected. PolyP65 exerts opposing effects on tPA- and uPA-mediated fibrinolysis, attenuating the fibrin cofactor function in tPA-mediated plasminogen activation. In contrast, polyP may facilitate the interaction between fibrin-independent uPA and plasminogen thereby accelerating plasmin generation and downstream fibrinolysis.
Topics: Fibrinolysin; Fibrinolysis; Humans; Plasminogen; Polyphosphates; Tissue Plasminogen Activator; Urokinase-Type Plasminogen Activator
PubMed: 32029503
DOI: 10.3324/haematol.2019.237966 -
American Journal of Physiology. Cell... Oct 2021Tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) are serine proteases and major activators of fibrinolysis in mammalian systems.... (Review)
Review
Tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) are serine proteases and major activators of fibrinolysis in mammalian systems. Because fibrinolysis is an essential component of the response to tissue injury, diverse cells, including cells that participate in the response to injury, have evolved receptor systems to detect tPA and uPA and initiate appropriate cell-signaling responses. Formation of functional receptor systems for the plasminogen activators requires assembly of diverse plasma membrane proteins, including but not limited to: the urokinase receptor (uPAR); integrins; -formyl peptide receptor-2 (FPR2), receptor tyrosine kinases (RTKs), the -methyl-d-aspartate receptor (NMDA-R), and low-density lipoprotein receptor-related protein-1 (LRP1). The cell-signaling responses elicited by tPA and uPA impact diverse aspects of cell physiology. This review describes rapidly evolving knowledge regarding the structure and function of plasminogen activator receptor assemblies. How these receptor assemblies regulate innate immunity and inflammation is then considered.
Topics: Animals; Enzyme Activation; Fibrinolysis; Humans; Immunity, Innate; Inflammation; Inflammation Mediators; Ligands; Plasminogen; Protein Conformation; Receptors, Urokinase Plasminogen Activator; Signal Transduction; Structure-Activity Relationship; Tissue Plasminogen Activator
PubMed: 34406905
DOI: 10.1152/ajpcell.00269.2021 -
Haematologica Mar 2020Plasminogen deficiency is an ultra-rare multisystem disorder characterized by the development of fibrin-rich pseudomembranes on mucous membranes. Ligneous... (Review)
Review
Plasminogen deficiency is an ultra-rare multisystem disorder characterized by the development of fibrin-rich pseudomembranes on mucous membranes. Ligneous conjunctivitis, which can result in vision impairment or loss, is the most frequent symptom reported. Affected systems may also include the respiratory tract, oropharynx, female reproductive tract, gingiva, middle ear, renal collecting system, skin and central nervous system. Untreated, plasminogen deficiency may result in significant reduction in quality of life and morbidity with potential life-threatening complications. Non-specific therapies are inadequate and plasminogen concentrates are not commercially available. The current understanding of plasminogen deficiency and management of disease symptoms and its progression are based on case reports/series and two small clinical trials. To date there has never been a comprehensive, international study to examine the natural history or optimal therapeutic intervention; knowledge gaps include identification of contributing factors and triggers of disease manifestations, inability to predict disease course, and insufficient real-world data for use of therapeutics. We have created an international, observational study (HISTORY) in a large cohort of persons with plasminogen deficiency and first-degree family members to address these gaps and to advance knowledge and care. HISTORY will build upon the established relationship between the Indiana Hemophilia and Thrombosis Center and the Fondazione Angelo Bianchi Bonomi, IRCCS Ca' Granda Ospedale Maggiore Policlinico - University of Milan and will utilize a modified version of the Prospective Rare Bleeding Disorders Database (PRO-RBDD). A biorepository containing samples from subjects with plasminogen deficiency will be established. This article describes the rationale behind the study and efforts towards its goals.
Topics: Conjunctivitis; Humans; Observational Studies as Topic; Plasminogen; Prospective Studies; Quality of Life; Registries
PubMed: 32001536
DOI: 10.3324/haematol.2019.241158 -
Journal of Thrombosis and Haemostasis :... Jun 2015Fibrinolysis appears in many diverse physiological situations, and the components of the system are well established, along with mechanistic details for the individual... (Review)
Review
Fibrinolysis appears in many diverse physiological situations, and the components of the system are well established, along with mechanistic details for the individual reactions and some high-resolution structures. Key questions in understanding the regulation of fibrinolysis surround mechanisms of initiation and propagation, the localization of fibrinolysis reactions to the fibrin clot, and the influence of fibrin structure and clot composition on thrombolysis. This review covers these key areas with a focus on recent developments on fibrin structure and binding, the effects of a variety of cell types, the consequences of histones and DNA released by neutrophils, and the influence of flow. A complete understanding of the regulation of fibrinolysis will come from the building of detailed mathematical models. Suitable models are at an early stage of development, but may improve as model clots increase in complexity to incorporate the components and interactions listed above.
Topics: Animals; Fibrin; Fibrinolysis; Fibrinolytic Agents; Humans; Plasminogen; Plasminogen Activators; Protein Binding; Thrombolytic Therapy
PubMed: 26149056
DOI: 10.1111/jth.12935 -
Blood Jan 2021Plasminogen activation rates are enhanced by cell surface binding. We previously demonstrated that exogenous plasminogen binds to phosphatidylserine-exposing and spread...
Plasminogen activation rates are enhanced by cell surface binding. We previously demonstrated that exogenous plasminogen binds to phosphatidylserine-exposing and spread platelets. Platelets contain plasminogen in their α-granules, but secretion of plasminogen from platelets has not been studied. Recently, a novel transmembrane lysine-dependent plasminogen receptor, Plg-RKT, has been described on macrophages. Here, we analyzed the pool of plasminogen in platelets and examined whether platelets express Plg-RKT. Plasminogen content of the supernatant of resting and collagen/thrombin-stimulated platelets was similar. Pretreatment with the lysine analog, ε-aminocaproic acid, significantly increased platelet-derived plasminogen (0.33 vs 0.08 nmol/108 platelets) in the stimulated supernatant, indicating a lysine-dependent mechanism of membrane retention. Lysine-dependent, platelet-derived plasminogen retention on thrombin and convulxin activated human platelets was confirmed by flow cytometry. Platelets initiated fibrinolytic activity in fluorescently labeled plasminogen-deficient clots and in turbidimetric clot lysis assays. A 17-kDa band, consistent with Plg-RKT, was detected in the platelet membrane fraction by western blotting. Confocal microscopy of stimulated platelets revealed Plg-RKT colocalized with platelet-derived plasminogen on the activated platelet membrane. Plasminogen exposure was significantly attenuated in thrombin- and convulxin-stimulated platelets from Plg-RKT-/- mice compared with Plg-RKT+/+ littermates. Membrane exposure of Plg-RKT was not dependent on plasminogen, as similar levels of the receptor were detected in plasminogen-/- platelets. These data highlight Plg-RKT as a novel plasminogen receptor in human and murine platelets. We show for the first time that platelet-derived plasminogen is retained on the activated platelet membrane and drives local fibrinolysis by enhancing cell surface-mediated plasminogen activation.
Topics: Animals; Blood Platelets; Humans; Mice; Plasminogen; Platelet Activation; Receptors, Cell Surface
PubMed: 32842150
DOI: 10.1182/blood.2020007263 -
Stroke Aug 2022Mechanical thrombectomy is a highly effective treatment for acute ischemic stroke caused by large-vessel occlusion in the anterior cerebral circulation, significantly... (Review)
Review
Mechanical thrombectomy is a highly effective treatment for acute ischemic stroke caused by large-vessel occlusion in the anterior cerebral circulation, significantly increasing the likelihood of recovery to functional independence. Until recently, whether intravenous thrombolysis before mechanical thrombectomy provided additional benefits to patients with acute ischemic stroke-large-vessel occlusion remained unclear. Given that reperfusion is a key factor for clinical outcome in patients with acute ischemic stroke-large-vessel occlusion and the efficacy of both intravenous thrombolysis and mechanical thrombectomy is time-dependent, achieving complete reperfusion with a single pass should be the primary angiographic goal. However, it remains undetermined whether extending the procedure with additional endovascular attempts or local lytics administration safely leads to higher reperfusion grades and whether there are significant public health and cost implications. Here, we outline the current state of knowledge and research avenues that remain to be explored regarding the consistent therapeutic benefit of intravenous thrombolysis in anterior circulation strokes and the potential place of adjunctive intra-arterial lytics administration, including alternative thrombolytic agent place.
Topics: Brain Ischemia; Fibrinolytic Agents; Humans; Ischemic Stroke; Plasminogen; Stroke; Thrombectomy; Thrombolytic Therapy; Tissue Plasminogen Activator; Treatment Outcome
PubMed: 35506385
DOI: 10.1161/STROKEAHA.122.039287