Inhibitor Plasminogen Activator Research Articles

Tranexamic acid for upper gastrointestinal bleeding

Background. In patients with trauma and significant bleeding or risk of significant bleeding it is advised to administer tranexamic acid (TXA) intravenously as early as possible at a loading dose of 1 g for 10 minutes, followed by 1 g for 8 hours. The effectiveness of TXA has been proven in various pathological conditions in large trials. TXA has been shown to reduce the need for blood transfusions.
 Objective. To describe the use of TXA for upper gastrointestinal tract (GIT) bleeding.
 Materials and methods. Analysis of literature sources on this topic.
 Results and discussion. The mechanism of TXA action is to inhibit plasminogen activation and reduce fibrin degradation, however, its features are not clear. With the use of TXA, the strength of the blood clot and its resistance to lysis increases. The use of TXA in gastrointestinal bleeding was analyzed in the Cochrane Review (2012) of seven randomized controlled trials involving 1,654 patients. TXA was compared with placebo, lansoprazole or cimetidine. There was a lower mortality in the TXA group, however, after taking into account possible bias, this trend did not persist. A randomized placebo-controlled study of HALT-IT included 12,009 patients with gastrointestinal bleeding who were prescribed TXA (loading dose of 1+3 g for 24 hours) or placebo. The primary endpoint was death from bleeding within 5 days. There were no differences in mortality or re-bleeding. The TXA group had a higher frequency of deep vein thrombosis and pulmonary embolism. One of the reasons for the lack of benefits of TXA in gastrointestinal bleeding is that the onset of such bleeding is difficult to detect immediately, and to achieve the effect of TXA as early as possible administration is necessary. In this case, >80 % of patients sought medical help >3 hours after the onset of bleeding. In addition, in 50 % of patients, the bleeding was due to esophageal varices due to liver disease. It is known that most coagulation factors are synthesized in the liver, so liver failure is a common cause of coagulopathies. When the liver is affected, the levels of vitamin-K-dependent procoagulants (coagulation factors II, VII, IX and X), coagulation factor V, as well as anticoagulants (proteins C and S, antithrombin) decrease. Levels of fibrinogen and acute phase proteins remain normal or increase. In case of liver failure, hyperfibrinolysis occurs and at the same time the risk of thrombosis increases significantly. In such patients there is a decrease in hemostatic blood reserve. In general, contraindications to the use of TXA include severe renal failure, seizures, disseminated intravascular coagulation without bleeding, arterial or venous thromboembolism, active bleeding from the upper urinary tract.
 Conclusions. 1. TXA is effective for most types of bleedings, however, there are some exceptions. 2. One should remember the side effects of TXA and follow the recommended method of administration. 3. TXA is not suitable for the treatment of gastrointestinal bleeding.

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells.

Transforming growth factor-β (TGF-β) is a secreted multifunctional factor that plays a key role in intercellular communication. Perturbations of TGF-β signaling can lead to breast cancer. TGF-β elicits its effects on proliferation and differentiation via specific cell surface TGF-β type I and type II receptors (i.e., TβRI and TβRII) that contain an intrinsic serine/threonine kinase domain. Upon TGF-β-induced heteromeric complex formation, activated TβRI elicits intracellular signaling by phosphorylating SMAD2 and SMAD3. These activated SMADs form heteromeric complexes with SMAD4 to regulate specific target genes, including plasminogen activation inhibitor 1 (PAI-1, encoded by the SERPINE1 gene). The induction of epithelial-to-mesenchymal transition (EMT) allows epithelial cancer cells at the primary site or during colonization at distant sites to gain an invasive phenotype and drive tumor progression. TGF-β acts as a potent inducer of breast cancer invasion by driving EMT. Here, we describe systematic methods to investigate TGF-β signaling and EMT responses using premalignant human MCF10A-RAS (M2) cells and mouse NMuMG epithelial cells as examples. We describe methods to determine TGF-β-induced SMAD2 phosphorylation by Western blotting, SMAD3/SMAD4-dependent transcriptional activity using luciferase reporter activity and SERPINE1 target gene expression by quantitative real-time-polymerase chain reaction (qRT-PCR). In addition, methods are described to examine TGF-β-induced EMT by measuring changes in morphology, epithelial and mesenchymal marker expression, filamentous actin staining and immunofluorescence staining of E-cadherin. Two selective small molecule TGF-β receptor kinase inhibitors, GW788388 and SB431542, were used to block TGF-β-induced SMAD2 phosphorylation, target genes and changes in EMT marker expression. Moreover, we describe the transdifferentiation of mesenchymal breast Py2T murine epithelial tumor cells into adipocytes. Methods to examine TGF-β-induced signaling and EMT in breast cancer may contribute to new therapeutic approaches for breast cancer.

Plasminogenuria is associated with podocyte injury, edema, and kidney dysfunction in incident glomerular disease.

Urinary plasminogen/plasmin, or plasmin (ogen) uria, has been demonstrated in proteinuric patients and exposure of cultured podocytes to plasminogen results in injury via oxidative stress pathways. A causative role for plasmin (ogen) as a "second hit" in kidney disease progression has yet to have been demonstrated in vivo. Additionally, association between plasmin (ogen) uria and kidney function in glomerular diseases remains unclear. We performed comparative studies in a puromycin aminonucleoside (PAN) nephropathy rat model treated with amiloride, an inhibitor of plasminogen activation, and measured changes in plasmin (ogen) uria. In a glomerular disease biorepository cohort (n=128), we measured time-of-biopsy albuminuria, proteinuria, and plasmin (ogen) uria for correlations with kidney outcomes. In cultured human podocytes, plasminogen treatment was associated with decreased focal adhesion marker expression with rescue by amiloride. Increased glomerular plasmin (ogen) was found in PAN rats and focal segmental glomerulosclerosis (FSGS) patients. PAN nephropathy was associated with increases in plasmin (ogen) uria and proteinuria. Amiloride was protective against PAN-induced glomerular injury, reducing CD36 scavenger receptor expression and oxidative stress. In patients, we found associations between plasmin (ogen) uria and edema status as well as eGFR. Our study demonstrates a role for plasmin (ogen)-induced podocyte injury in the PAN nephropathy model, with amiloride having podocyte-protective properties. In one of the largest glomerular disease cohorts to study plasminogen, we validated previous findings while suggesting a potentially novel relationship between plasmin (ogen) uria and estimated glomerular filtration rate (eGFR). Together, these findings suggest a role for plasmin (ogen) in mediating glomerular injury and as a viable targetable biomarker for podocyte-sparing treatments.

Sirtuin 5 promotes arterial thrombosis by blunting the fibrinolytic system.

Arterial thrombosis as a result of plaque rupture or erosion is a key event in acute cardiovascular events. Sirtuin 5 (SIRT5) belongs to the lifespan-regulating sirtuin superfamily and has been implicated in acute ischaemic stroke and cardiac hypertrophy. This project aims at investigating the role of SIRT5 in arterial thrombus formation. Sirt5 transgenic (Sirt5Tg/0) and knock-out (Sirt5-/-) mice underwent photochemically induced carotid endothelial injury to trigger arterial thrombosis. Primary human aortic endothelial cells (HAECs) were treated with SIRT5 silencing-RNA (si-SIRT5) as well as peripheral blood mononuclear cells from acute coronary syndrome (ACS) patients and non-ACS controls (case-control study, total n = 171) were used to increase the translational relevance of our data. Compared to wild-type controls, Sirt5Tg/0 mice displayed accelerated arterial thrombus formation following endothelial-specific damage. Conversely, in Sirt5-/- mice, arterial thrombosis was blunted. Platelet function was unaltered, as assessed by ex vivo collagen-induced aggregometry. Similarly, activation of the coagulation cascade as assessed by vascular and plasma tissue factor (TF) and TF pathway inhibitor expression was unaltered. Increased thrombus embolization episodes and circulating D-dimer levels suggested augmented activation of the fibrinolytic system in Sirt5-/- mice. Accordingly, Sirt5-/- mice showed reduced plasma and vascular expression of the fibrinolysis inhibitor plasminogen activator inhibitor (PAI)-1. In HAECs, SIRT5-silencing inhibited PAI-1 gene and protein expression in response to TNF-α. This effect was mediated by increased AMPK activation and reduced phosphorylation of the MAP kinase ERK 1/2, but not JNK and p38 as shown both in vivo and in vitro. Lastly, both PAI-1 and SIRT5 gene expressions are increased in ACS patients compared to non-ACS controls after adjustment for cardiovascular risk factors, while PAI-1 expression increased across tertiles of SIRT5. SIRT5 promotes arterial thrombosis by modulating fibrinolysis through endothelial PAI-1 expression. Hence, SIRT5 may be an interesting therapeutic target in the context of atherothrombotic events.

Redistribution of TPA Fluxes in the Presence of PAI-1 Regulates Spatial Thrombolysis

The fibrin clot is gelatinous matter formed upon injury to stop blood loss and is later destroyed by fibrinolysis, an enzymatic cascade with feedback. Pharmacological fibrinolysis stimulation is also used to destroy pathological, life-threatening clots and thrombi (thrombolysis). The regulation of the nonlinear spatially nonuniform fibrinolytic process in thrombolysis is not currently well understood. We developed a reaction-diffusion-advection model of thrombolysis by tissue plasminogen activator (TPA) in an occluded vessel with a pressure gradient. Sensitivity-analysis-based model reduction was used to reveal the critical processes controlling different steps of thrombolysis. The propagation of thrombolysis in the system without flow was predominantly controlled by TPA diffusion, whereas transport of other active components was rendered nonessential either by their high fibrin-binding parameters and short lifetimes or their initial uniform distribution. The concentration of the main TPA inhibitor plasminogen activator inhibitor 1 (PAI-1) controlled both the extent of lysis propagation and the shape of fibrin spatial distribution during lysis. Interestingly, PAI-1 remained important even when its concentration was an order of magnitude below that of TPA because of its role at the edge of the diffusing TPA front. The system was robust to reaction rate constant perturbations. Using these data, a reduced model of thrombolysis was proposed. In the presence of flow, convection of TPA was the critical controlling process; although the role of PAI-1 concentration was much less in the presence of flow, its influence became greater in the presence of collateral bypassing vessels, which sufficiently reduced TPA flux through the thrombus. Flow bypass through the collateral vessel caused a decrease in TPA flux in the clotted vessel, which increased the PAI-1/TPA ratio, thus making PAI-1-induced inhibition relevant for the regulation of spatial lysis up to its arrest.

Human Plasminogen Exacerbates Clostridioides difficile Enteric Disease and Alters the Spore Surface

The protease plasmin is an important wound healing factor, but it is not clear how it affects gastrointestinal infection-mediated damage, such as that resulting from Clostridioides difficile. We investigated the role of plasmin in C difficile-associated disease. This bacterium produces a spore form that is required for infection, so we also investigated the effects of plasmin on spores. C57BL/6J mice expressing the precursor to plasmin, the zymogen human plasminogen (hPLG), or infused with hPLG were infected with C difficile, and disease progression was monitored. Gut tissues were collected, and cytokine production and tissue damage were analyzed by using proteomic and cytokine arrays. Antibodies that inhibit either hPLG activation or plasmin activity were developed and structurally characterized, and their effects were tested in mice. Spores were isolated from infected patients or mice and visualized using super-resolution microscopy; the functional consequences of hPLG binding to spores were determined. hPLG localized to the toxin-damaged gut, resulting in immune dysregulation with an increased abundance of cytokines (such as interleukin [IL] 1A, IL1B, IL3, IL10, IL12B, MCP1, MP1A, MP1B, GCSF, GMCSF, KC, TIMP-1), tissue degradation, and reduced survival. Administration of antibodies that inhibit plasminogen activation reduced disease severity in mice. C difficile spores bound specifically to hPLG and active plasmin degraded their surface, facilitating rapid germination. We found that hPLG is recruited to the damaged gut, exacerbating C difficile disease in mice. hPLG binds to C difficile spores, and, upon activation to plasmin, remodels the spore surface, facilitating rapid spore germination. Inhibitors of plasminogen activation might be developed for treatment of C difficile or other infection-mediated gastrointestinal diseases.

Lupeol suppresses plasminogen activator inhibitor-1-mediated macrophage recruitment and attenuates M2 macrophage polarization

Tumor-associated macrophages (TAMs) are closely related with poor prognosis of cancers. The current study investigated whether lupeol regulates TAMs by focusing on the recruitment and polarization of macrophages. We found that lupeol suppressed the recruitment of THP-1 macrophages (THP-1 cells differentiated into macrophages) towards H1299 lung carcinoma cells by inhibiting plasminogen activator inhibitor-1 (PAI-1) production from H1299 cells. The reduced migration of THP-1 macrophages by lupeol was recovered by adding recombinant human PAI-1 as a chemoattractant. Knockdown of PAI-1 or treatment of tiplaxtinin, a PAI-1 inhibitor, in H1299 cells abrogated the chemotaxis of macrophages. Furthermore, lupeol suppressed the interleukin (IL)-4- and IL-13-induced M2 macrophage polarization. The mRNA expression of M2 macrophage markers and the phosphorylation of signal transducer and activator of transcription 6 (STAT6) were commonly decreased by lupeol in RAW264.7 cells. In addition, lupeol-suppressed M2 macrophage polarization led to the reduced migration of Lewis lung carcinoma (LLC) cells. Taken together, our results suggest that lupeol attenuates PAI-1-mediated macrophage recruitment towards cancer cells and inhibits M2 macrophage polarization.

The never ending success story of tranexamic acid in acquired bleeding.

Tranexamic acid (TXA) is an anti-fibrinolytic agent that acts by inhibiting plasminogen activation and fibrinolysis. Although its first clinical use dates back more than 50 years, this hemostatic agent is still the object of intense clinical and developmental research. In particular, renewed interest in TXA has arisen following evidence that it has a beneficial effect in reducing blood loss in a variety of medical and surgical conditions at increased risk of bleeding. Given this characteristic, TXA is currently considered a mainstay of Patient Blood Management programs aimed at reducing patients’ exposure to allogeneic blood transfusion. Importantly, recent large randomized controlled trials have consistently documented that the use of TXA confers a survival advantage in a number of globally critical clinical conditions associated with acute bleeding, including traumatic injury and post-partum hemorrhage, without increasing the thromboembolic risk.

Increased dipeptidyl peptidase-4 accelerates chronic stress-related thrombosis in a mouse carotid artery model.

Exposure to chronic psychosocial stress is a risk factor for metabolic cardiovascular disorders. Given that dipeptidyl peptidase-4 (DPP-4) has an important role in human pathobiology, we investigated the role of DPP-4 in stress-related thrombosis in mice, focusing on oxidative stress and the von Willebrand factor (vWF)-cleaving protease ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13). Male mice randomly assigned to nonstress and 2-week immobilized-stress groups underwent iron chloride3 (FeCl3)-induced carotid artery thrombosis surgery for morphological and biochemical studies at specific times. On day 14 post-stress/surgery, stress had enhanced the lengths and weights of arterial thrombi, with alterations of plasma DPP-4, plasminogen activation inhibitor-1 and ADAMTS13. The stressed mice had increased levels of vascular cell adhesion molecule-1, intracellular adhesion molecule-1, monocyte chemoattractant protein-1, gp91phox, p22phox, matrix metalloproteinase-2 (MMP-2), MMP-9, cathepsins S and K mRNAs and/or proteins, and reduced levels of endothelial nitric oxide synthase, catalase and superoxide dismutase-1 mRNAs and/or proteins. Stress also accelerated arterial endothelial cell damage. The DPP-4 inhibitor anagliptin ameliorated the stress-induced targeted molecular and morphological changes and thrombosis. In vitro, DPP-4 inhibition also mitigated the alterations in the targeted ADAMTS13 and other oxidative and inflammatory molecules in human umbilical vein endothelial cells in response to H2O2. DPP-4 inhibition appeared to improve the FeCl3-induced thrombosis in mice that received stress, possibly via the improvement of ADAMTS13 and oxidative stress, suggesting that DPP-4 could become a novel therapeutic target for chronic psychological stress-related thrombotic events in metabolic cardiovascular disorders.

Synergy between plasminogen activator inhibitor-1, α-synuclein, and neuroinflammation in Parkinson’s disease

Parkinson’s disease (PD) is a progressive degenerative nervous system disorder and is the second most common neurodegenerative disorder in the elderly population. The disease originates from the loss of dopamine-producing neurons in the substantia nigra in the brain, resulting in unregulated activity of the basal ganglia. Αlpha-synuclein (α-syn) is a protein found to aggregate in the substantia nigra region of patients with PD, forming Lewy Body inclusions; its aggregation may contribute to neuronal cell death in PD. This work hypothesizes about the synergistic relationship between α-syn aggregation and neuroinflammation to up-regulate expression of the serine protease inhibitor (serpin) plasminogen activator inhibitor-1 (PAI-1). The protease, plasmin, has been shown to cleave extracellular α-syn (including its monomeric, oligomeric, and fibrillary forms), resulting in less aggregation and Lewy Body formation. The zymogen plasminogen is converted to its active serine protease form, plasmin, either by tissue plasminogen activator (tPA) or by urokinase plasminogen activator (uPA) bound to urokinase receptor (uPAR). Both tPA and uPA/uPAR are inhibited by PAI-1. Thus, when PAI-1 levels increase, less plasmin is generated, which would lead to reduced proteolysis of α-syn. Expression of PAI-1 is increased both in inflammatory environments and in the presence of extracellular α-syn aggregates. This scenario suggests a pathological amplification loop: increased extracellular α-syn aggregation activates an inflammatory response from microglia and astrocytes, increasing PAI-1 levels, and decreasing the generation of plasmin. With reduced plasmin, less α-syn can be cleaved, and aggregation continues, sustaining the pathological process. Understanding this putative pathogenic loop could provide insight into the means by which neurodegeneration progresses in PD, and it may offer possible novel therapeutic strategies.

Nebulized Tranexamic Acid for the Use of Epistaxis: A Case Report.

Tranexamic acid is an antifibrinolytic agent and functions as a competitive inhibitor of plasminogen activation, promoting hemostasis. Topical application of tranexamic acid for the control of epistaxis has been described in the literature, mainly through administration with gauze and packing. There is limited evidence for the use of tranexamic acid via alternative routes of administration such as nebulization. We describe a patient who presented to the emergency department with epistaxis who was treated with nebulized tranexamic acid. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Our case provides an alternative treatment modality using nebulizing tranexamic acid to help manage epistaxis in patients that cannot be managed with topical antifibrinolytic therapy administered by other means.

EPIGENETIC CLOCKS OF COMPUTED TOMOGRAPHY MEASURES OF FATTY ORGANS

DNA methylation (DNAm) based biomarkers collectively known as “epigenetic clock” yielding accurate measure of age in any tissue across the entire life course have associated with a large host of age-related conditions. To study their implications in metabolic syndromes, we analyzed computed tomography (CT) derived measures of adiposity with 1) three widely-used clocks: Horvath, Hannum, and Levine (PhenoAge), and a newly developed clock DNAmGrimAge, and 2) seven DNAm based plasma proteins, the components comprising the DNAmGrimAge. Age-adjusted DNAmGrimAge and several age-adjusted DNAm plasma proteins including plasminogen activation inhibitor 1 (PAI-1) stand our followed by adrenomedullin and leptin. Fatty liver (r ≤ 0.41, P ≤ 2.9E-37) and excess visceral adipose tissue fat (r ≤0.42, P ≤ 1.5E-41) are the most significant CT-based measures of DNAmPAI-1 and DNAmGrimAge. Furthermore, age-adjusted DNAmGrimAge and age-adjusted DNAmPAI-1 continued showing the most significant relationship with lifestyle factors including healthy diet and educational attainment in expected directions.

TAFI deficiency causes maladaptive vascular remodeling after hemophilic joint bleeding.

Excessive vascular remodeling is characteristic of hemophilic arthropathy (HA) and may contribute to joint bleeding and the progression of HA. Mechanisms for pathological vascular remodeling after hemophilic joint bleeding are unknown. In hemophilia, activation of thrombin-activatable fibrinolysis inhibitor (TAFI) is impaired, which contributes to joint bleeding and may also underlie the aberrant vascular remodeling. Here, hemophilia A (factor VIII-deficient; FVIII-deficient) mice or TAFI-deficient mice with transient (antibody-induced) hemophilia A were used to determine the role of FVIII and TAFI in vascular remodeling after joint bleeding. Excessive vascular remodeling and vessel enlargement persisted in FVIII-deficient and TAFI-deficient mice, but not in transient hemophilia WT mice, after similar joint bleeding. TAFI-overexpression in FVIII-deficient mice prevented abnormal vessel enlargement and vascular leakage. Age-related vascular changes were observed with FVIII or TAFI deficiency and correlated positively with bleeding severity after injury, supporting increased vascularity as a major contributor to joint bleeding. Antibody-mediated inhibition of uPA also prevented abnormal vascular remodeling, suggesting that TAFI's protective effects include inhibition of uPA-mediated plasminogen activation. In conclusion, the functional TAFI deficiency in hemophilia drives maladaptive vascular remodeling in the joints after bleeding. These mechanistic insights allow targeted development of potentially new strategies to normalize vascularity and control rebleeding in HA.

The serine protease inhibitors and SERPINE1/2 disrupt prostaglandin E2 production and hyaluronic acid retention in FSH-stimulated pig cumulus-oocyte complexes.

The serine proteases, tissue- and urokinase-type plasminogen activators (PLAT and PLAU) and their inhibitors SERPINE1/2 are regulators of plasminogen to plasmin conversion. They are widely expressed in ovarian tissues, including granulosa and cumulus cells, and their expression is regulated by gonadotropins. The aim of this work was to assess the effect of serine protease inhibitors (aprotinin and AEBSF) and SERPINE1/2 on FSH-induced cumulus cell expansion, the production of prostaglandin E2 (PGE2) and retention of hyaluronic acid (HA) in expanding cumulus. The serine protease activity proved to be essential for the production of PGE2 and also for the retention of HA; the inhibition of plasminogen activators by SERPINE1/2 had the same effect. Collectively, these data indicate that plasmin is required for proper function of expanding cumulus cells in vitro and presumably also in vivo in the pre-ovulatory follicles.

Lipoprotein-A Fails to Inhibit Plasminogen Activation and Fibrinolysis in a Whole Blood Model

Bartley, Matthew G. MD, MS; Vigneshwar, Navin MD; Moore, Ernest E. MD, FACS; Kelher, Marguerite MS; Silliman, Christopher C. MD, PhD; Samuels, Jason MD; Coleman, Julia R. MD, MPH; Sauaia, Angela A. MD, PhD; Cohen, Mitchell J. MD, FACS; Banerjee, Anirban O. PhD Author Information

Changes in coagulation of sepsis rats with protein-malnutrition or energy-malnutrition

To investigate the changes in coagulation of sepsis rats with protein-malnutrition or energy-malnutrition. 108 male Sprague-Dawley (SD) rats were divided into three groups by random number table, with 36 rats in each group. The rats in normal feeding group were given a free diet (27 g/d, containing 18% protein fodder), and the rats in protein-malnutrition group were given a low protein diet (27 g/d, containing 5% protein fodder). The rats in energy-malnutrition group were given a low energy diet (9 g/d, containing 18% protein fodder). After 4 weeks of continuous feeding, 8 rats from each group were sacrificed for malnutrition evaluation. The weights of body, thymus and spleen were measured. The percentages of spleen T lymphocyte subsets and M1 macrophage were determined by flow cytometry. Plasma interleukins (IL-6 and IL-10) levels were determined by enzyme-linked immunosorbent assay (ELISA). The remaining 28 rats in each group were collected for cecal ligation and puncture (CLP) to reproduce the sepsis model, 20 rats of which were used for Kaplan-Meier survival analysis, and the other 8 rats were sacrificed at 8 hours after CLP. The levels of plasma IL-6 and IL-10 were determined by ELISA, and the percentage of spleen M1 macrophages was determined by flow cytometry. The mRNA expressions of tissue factor (TF) and plasminogen activation inhibitor-1 (PAI-1) in liver tissue were determined by reverse transcription-polymerase chain reaction (RT-PCR). Pearson correlation method was used to analyze the correlation between the mRNA expressions of TF and PAI-1 and IL-6 in rats after CLP. (1) After 4 weeks of feeding, the rats in the normal feeding group and protein-malnutrition group gained weight, while those in the energy-malnutrition group lost 25% of their initial body weight. The weights of body, thymus and spleen in the protein-malnutrition group and the energy-malnutrition group were significantly lower than those in the normal feeding group. Compared with the normal feeding group and the protein-malnutrition group, the percentages of spleen CD3+T lymphocytes, CD4+T lymphocytes, M1 macrophages and plasma IL-6 levels were significantly increased in the energy-malnutrition group [CD3+T lymphocytes percentage: (52.1±3.7)% vs. (46.9±3.9)%, (44.5±2.2)%; CD4+T lymphocyte percentages: (35.0±3.6)% vs. (26.3±2.2)%, (25.1±2.3)%; M1 macrophage percentages: (8.7±2.0)% vs. (3.2±1.3)%, (4.2±1.1)%; IL-6 (ng/L): 129.4±16.2 vs. 48.1±10.0, 53.0±8.3, all P < 0.05]. (2) Kaplan-Meier survival analysis at 7 days after CLP showed: all rats in the energy-malnutrition group died, and the 7-day cumulative survival rate was significantly lower than that in the normal feeding group and the protein-malnutrition group [0% (0/20) vs. 35% (7/20), 55% (11/20), both P < 0.05]. The mortality of the normal feeding group was 65%, which was consistent with moderate CLP mortality, indicating that the CLP model was successfully prepared. After CLP, the plasma IL-6 level in the protein-malnutrition group was significantly lower than that in the normal feeding group [IL-6 (ng/L): 154.6±34.7 vs. 233.4±41.2, P < 0.05]. Compared with the normal feeding group, the mRNA expressions of TF and PAI-1 in liver and plasma IL-6 levels in the energy-malnutrition group were significantly increased [TF mRNA (2-ΔΔCT): 4.5±2.2 vs. 1.1±0.7, PAI-1 mRNA (2-ΔΔCT): 3.3±1.8 vs. 1.3±0.9, IL-6 (ng/L): 382.7±118.2 vs. 233.4±41.2, all P < 0.05], the percentage of M1 macrophages in spleen was significantly lowered [(8.9±2.4)% vs. (15.2±5.4)%, P < 0.05]. There was no significant difference in plasma IL-10 level among all the groups. Correlation analysis showed that the mRNA expressions of TF and PAI-1 in the liver of rats after CLP were positively correlated with plasma IL-6 level (r1 = 0.644, r2 = 0.574, both P < 0.01). Long-term sustained stress (starvation) leads to sustained chronic inflammatory state, and stimulated the release of related inflammatory factors and activation of the coagulation system after infection. And the inflammatory factors in sepsis rats without sustained stress protein malnutrition were significantly reduced.

Looking at Lp(a) and Related Cardiovascular Risk: from Scientific Evidence and Clinical Practice

A considerable body of data from genetic and epidemiological studies strongly support a causal relationship between high lipoprotein(a) [Lp(a)] levels, and the development of atherosclerosis and cardiovascular disease. This relationship is continuous, unrelated to Lp(a) threshold, and independent of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol levels. Unfortunately, the mechanism(s) through which Lp(a) promotes atherosclerosis are not clarified yet. Suggested hypotheses include: an increased Lp(a)-associated cholesterol entrapment in the arterial intima followed by inflammatory cell recruitment, abnormal upload of proinflammatory oxidized phospholipids, impaired fibrinolysis by inhibition of plasminogen activation, and enhanced coagulation, through inhibition of the tissue factor pathway inhibitor. This review is aimed at summarizing the available evidence on the topic. There are two clinical forms, isolated hyperlipidemia(a) [HyperLp(a)] with acceptable LDL-C levels (< 70mg/dL), and combined elevation of Lp(a) and LDL-C in plasma. To date, no drugs that selectively decrease Lp(a) are available. Some novel lipid-lowering drugs can lower Lp(a) levels, but to a limited extent, as their main effect is aimed at decreasing LDL-C levels. Significant Lp(a) lowering effects were obtained with nicotinic acid at high doses. However, adverse effects apart, nicotinic acid is no longer prescribed and available in Europe for clinical use, after European Agency of Medicines (EMA) ban. The only effective therapeutic option for now is Lipoprotein Apheresis (LA), albeit with some limitations. Lastly, it is to be acknowledged that the body of evidence confirming that reducing plasma isolated elevation of Lp(a) brings cardiovascular benefit is still insufficient. However, the growing bulk of clinical, genetic, mechanistic, and epidemiological available evidence strongly suggests that Lp(a) is likely to be the smoking gun.

The Use of Tranexamic Acid (TXA) for the Management of Hemorrhage in Trauma Patients in the Prehospital Environment: Literature Review and Descriptive Analysis of Principal Themes.

Tranexamic acid (TXA) is an antifibrinolytic agent used to prevent traumatic exsanguination. It was first introduced to clinical practice for the management of patients with bleeding disorders, especially adapted to reduce bleeding in hemophiliacs undergoing oral surgical interventions. TXA exerts its action on the coagulation process by competitively inhibiting plasminogen activation, thereby reducing conversion of plasminogen into plasmin. This ultimately prevents fibrinolysis and reduces hemorrhage. Thus, TXA may be well suited for the management of traumatic hemorrhage in the prehospital setting.Despite multiplicity of studies on the use of TXA in clinical practice, there is no consensus regarding the use of TXA for the management of hemorrhage in trauma patients in the prehospital environment. Thus, a review on this topic was warranted. An extensive literature search yielded 14 full journal articles which met the inclusion criteria. These articles were thoroughly analyzed and the following themes were identified: "dose of TXA administration," "route of TXA administration," "optimal window of TXA administration," "safety of TXA use," "clinical effectiveness of TXA application," and the "feasibility of TXA use in the prehospital setting."Overall, to achieve the best possible outcomes, the literature supports the use of a loading dose of 1 g of TXA, followed by 1 g infusion over 8 h, given by intravenous administration within a 3-h window period of traumatic injury. TXA is very effective and safe to use in the prehospital setting, and its use is clinically and economically feasible.

Endothelial miR-30c suppresses tumor growth via inhibition of TGF-β-induced Serpine1.

In tumors, extravascular fibrin forms provisional scaffolds for endothelial cell (EC) growth and motility during angiogenesis. We report that fibrin-mediated angiogenesis was inhibited and tumor growth delayed following postnatal deletion of Tgfbr2 in the endothelium of Cdh5-CreERT2 Tgfbr2fl/fl mice (Tgfbr2iECKO mice). ECs from Tgfbr2iECKO mice failed to upregulate the fibrinolysis inhibitor plasminogen activator inhibitor 1 (Serpine1, also known as PAI-1), due in part to uncoupled TGF-β-mediated suppression of miR-30c. Bypassing TGF-β signaling with vascular tropic nanoparticles that deliver miR-30c antagomiRs promoted PAI-1-dependent tumor growth and increased fibrin abundance, whereas miR-30c mimics inhibited tumor growth and promoted vascular-directed fibrinolysis in vivo. Using single-cell RNA-Seq and a NanoString miRNA array, we also found that subtypes of ECs in tumors showed spectrums of Serpine1 and miR-30c expression levels, suggesting functional diversity in ECs at the level of individual cells; indeed, fresh EC isolates from lung and mammary tumor models had differential abilities to degrade fibrin and launch new vessel sprouts, a finding that was linked to their inverse expression patterns of miR-30c and Serpine1 (i.e., miR-30chi Serpine1lo ECs were poorly angiogenic and miR-30clo Serpine1hi ECs were highly angiogenic). Thus, by balancing Serpine1 expression in ECs downstream of TGF-β, miR-30c functions as a tumor suppressor in the tumor microenvironment through its ability to promote fibrin degradation and inhibit blood vessel formation.

Acute fibrinolysis shutdown occurs early in septic shock and is associated with increased morbidity and mortality: results of an observational pilot study

BackgroundSeptic coagulopathy represents a very dynamic disease entity, tilting from initial hypercoagulability towards a subsequent hypocoagulable disease state, entitled overt disseminated intravascular coagulation. Acute fibrinolysis shutdown has recently been described to be a crucial component of initial hypercoagulability in critically ill patients, although the underlying pathomechanisms, the specific temporal kinetics and its outcome relevance in patients with sepsis remain to be determined.MethodsIn total, 90 patients (30 with septic shock, 30 surgical controls and 30 healthy volunteers) were enrolled. Blood samples were collected at sepsis onset or prior and immediately after the surgical procedure as well as 3 h, 6 h, 12 h, 24 h, 48 h and 7 d later, whereas blood samples from healthy volunteers were collected once. Besides viscoelastic and aggregometric point-of-care testing (POCT), enzyme-linked immunosorbent and thrombin generation assays and liquid chromatography–mass spectrometry-based measurements were performed.ResultsAs assessed by viscoelastic POCT, fibrinolysis shutdown occurred early in sepsis. Significant increases in tissue plasminogen activator had no effect on thromboelastometrical lysis indices (LIs). Contrariwise, plasminogen activator inhibitor-1 was already significantly increased at sepsis onset, which was paralleled by significantly increased LIs in patients suffering from septic shock in comparison with both control groups. This effect persisted throughout the 7-day observation period and was most pronounced in severely ill as well as non-surviving septic patients. Thromboelastometrical LI, therefore, proved to be suitable for early diagnosis [e.g. LI 45 min: area under the curve (AUC) up to 0.933] as well as prognosis (e.g. LI 60 min: AUC up to 1.000) of septic shock.ConclusionsEarly inhibition of plasminogen activation leads to acute fibrinolysis shutdown with improved clot stability and is associated with increased morbidity and mortality in septic patients.Trial registration This study was approved by the local ethics committee (Ethics Committee of the Medical Faculty of Heidelberg; Trial-Code No. S247-2014/German Clinical Trials Register (DRKS)-ID: DRKS00008090; retrospectively registered: 07.05.2015). All study patients or their legal representatives signed written informed consent.