Proteomic Insights into Biology of Bipolar Disorder: Implications for Health Complexity and Mortality

OBJECTIVE

The present study has the following objectives: 1) identify differentially expressed proteins and pathways in blood samples of BD compared to healthy controls by employing high-throughput proteomics and bioinformatics and 2) characterize disease-related molecular signatures through in-depth analysis of the differentially expressed proteins and pathways.

METHODS

Blood samples from BD patients (n=10) classified into high (BD+) or poor functioning (BD-), based on functional and cognitive status, and healthy controls (n=5) were analyzed using mass spectrometry-based proteomic analysis. Bioinformatics was performed to detect biological processes, pathways, and diseases related to BD.

RESULTS

Eight proteins exclusively characterized the molecular profile of patients with BD+ compared to HC, while 26 altered proteins were observed in the BD- group. These altered proteins were mainly enriched in biological processes related to lipid metabolism, complement system and coagulation cascade, and cardiovascular diseases; all these changes were more prominent in the BD- group.

CONCLUSION

These findings may represent systemic alterations that occur with the progression of the illness and a possible link between BD and medical comorbidities. Such comprehensive understanding provides valuable insights for targeted interventions, addressing mental and physical health aspects in subjects with BD. Despite these promising findings, further research is warranted, encompassing larger sample cohorts and incorporating biological validation through molecular biology methods.

The combination of paeonol, diosmetin-7-O-β-D-glucopyranoside, and 5-hydroxymethylfurfural from Trichosanthis pericarpium alleviates arachidonic acid-induced thrombosis in a zebrafish model

Trichosanthis fruit (TF) is a classic medicinal material obtained from Shandong, China. The peel of this fruit (Trichosanthis pericarpium, TP) is known to exert anti-thrombotic effects. However, the anti-thrombotic active components and mechanisms of TP have yet to be fully elucidated. Combined with zebrafish models and high-performance liquid chromatography (HPLC), this study evaluated the endogenous anti-thrombotic effects with the combination of three compounds from TP. First, we used HPLC to investigate the components in the water extract of TP. Next, we used the zebrafish model to investigate the anti-thrombotic activity of the three compound combinations by evaluating a range of indicators. Finally, the expression of related genes was detected by real-time quantitative polymerase chain reaction (qPCR). HPLC detected a total of eight components in TP water extract, with high levels of paeonol (Pae), diosmetin-7-O-β-D-glucopyranoside (diosmetin-7-O-glucoside), and 5-hydroxymethylfurfural (5-HMF). The most significant anti-thrombotic activity was detected when the Pae: diosmetin-7-O-glucoside:5-HMF ratio was 4:3:3. qPCR analysis revealed that the abnormal expression levels of f2, fga, fgb, vwf, ptgs1, and tbxas1 induced by arachidonic acid (AA) were improved. The combination of Pae, diosmetin-7-O-glucoside, and 5-HMF may alleviate AA-induced thrombosis by inhibiting the inflammatory reaction, coagulation cascade reaction, and arachidonic acid metabolism pathways.

Research into New Molecular Mechanisms in Thrombotic Diseases Paves the Way for Innovative Therapeutic Approaches

Thrombosis is a multifaceted process involving various molecular components, including the coagulation cascade, platelet activation, platelet-endothelial interaction, anticoagulant signaling pathways, inflammatory mediators, genetic factors and the involvement of various cells such as endothelial cells, platelets and leukocytes. A comprehensive understanding of the molecular signaling pathways and cell interactions that play a role in thrombosis is essential for the development of precise therapeutic strategies for the treatment and prevention of thrombotic diseases. Ongoing research in this field is constantly uncovering new molecular players and pathways that offer opportunities for more precise interventions in the clinical setting. These molecular insights into thrombosis form the basis for the development of targeted therapeutic approaches for the treatment and prevention of thrombotic disease. The aim of this review is to provide an overview of the pathogenesis of thrombosis and to explore new therapeutic options.

New High-Affinity Thrombin Aptamers for Advancing Coagulation Therapy: Balancing Thrombin Inhibition for Clot Prevention and Effective Bleeding Management with Antidote

Thrombin is a key enzyme involved in blood clotting, and its dysregulation can lead to thrombotic diseases such as stroke, myocardial infarction, and deep vein thrombosis. Thrombin aptamers have the potential to be used as therapeutic agents to prevent or treat thrombotic diseases. Thrombin DNA aptamers developed in our laboratory exhibit high affinity and specificity to thrombin. In vitro assays have demonstrated their efficacy by significantly decreasing Factor II activity and increasing PT and APTT times in both plasma and whole blood. Aptamers AYA1809002 and AYA1809004, the two most potent aptamers, exhibit high affinity for their target, with affinity constants (Kd) of 10 nM and 13 nM, respectively. Furthermore, the in vitro activity of these aptamers displays dose-dependent behavior, highlighting their efficacy in a concentration-dependent manner. In vitro stability assessments reveal that the aptamers remain stable in plasma and whole blood for up to 24 h. This finding is crucial for their potential application in clinical settings. Importantly, the thrombin inhibitory activity of the aptamers can be reversed by employing reverse complement sequences, providing a mechanism to counteract their anticoagulant effects when necessary to avoid excessive bleeding. These thrombin aptamers have been determined to be safe, with no observed mutagenic or immunogenic effects. Overall, these findings highlight the promising characteristics of these newly developed thrombin DNA aptamers, emphasizing their potential for therapeutic applications in the field of anticoagulation therapy. Moreover, the inclusion of an antidote in the coagulation therapy regimen can improve patient safety, ensure greater therapeutic efficacy, and minimize risk during emergency situations.

A Rare Case of Acquired Factor VIII Deficiency in an Elderly Male With a History of Rheumatoid Arthritis

Acquired hemophilia A (AHA) or factor VIII (FVIII) deficiency is caused by autoantibodies targeting FVIII in the blood coagulation pathway; it is a rare condition making it challenging to diagnose. A timely diagnosis is crucial, without which there is a risk of catastrophic bleeding. We report a case of a patient with a history of duodenal arteriovenous malformations, previously on apixaban, who presented with four days of melena. On admission he was found to have a hemoglobin of 5.7 and elevated partial thromboplastin time (PTT), promoting further workup showing FVIII levels of <1%, with a mixing study that failed to correct suggesting the presence of inhibitors against FVIII. Other characteristics of this patient's cases included controlled rheumatoid arthritis without detectable rheumatoid factor or increased erythrocyte sedimentation rate (ESR). The patient was initially treated with prednisone and intravenous immunoglobulins, but an insufficient response prompted the initiation of recombinant factor VII, rituximab, and cyclophosphamide during hospitalization.

Bilateral Deep Vein Thrombosis (DVT) as a Harbinger of Lung Adenocarcinoma: A Rare Presentation

Oncologic disorders, such as lung adenocarcinoma, can intricately interplay with the coagulation cascade, often leading to thromboembolic events, of which deep vein thrombosis (DVT) stands out prominently. In this report, we present a unique case of a 50-year-old non-smoking Jordanian male who exhibited bilateral DVT as an unexpected preliminary manifestation of an aggressive lung adenocarcinoma. Although the patient did not possess common risk factors for DVT, the bilateral presentation drew attention to the possibility of an underlying malignancy. Subsequent investigations revealed a stage 4 primary lung adenocarcinoma. This case underscores the imperative of maintaining a broad differential in cases of DVT, especially when presenting bilaterally and without evident etiology. Such early detection and intervention, accompanied by collaborative medical strategies and specialized care, can play a pivotal role in enhancing patient prognosis and survival rates. This case exemplifies the potential of DVT, particularly when bilateral, as a harbinger of a more sinister underlying pathology like lung adenocarcinoma.

Monitoring the Formation of Fibrin Clots as Part of the Coagulation Cascade Using Fluorescent Single-Walled Carbon Nanotubes

Blood coagulation is a critical defense mechanism against bleeding that results in the conversion of liquid blood into a solid clot through a complicated cascade, which involves multiple clotting factors. One of the final steps in the coagulation pathway is the conversion of fibrinogen to insoluble fibrin mediated by thrombin. Because coagulation disorders can be life-threatening, the development of novel methods for monitoring the coagulation cascade dynamics is of high importance. Here, we use near-infrared (NIR)-fluorescent single-walled carbon nanotubes (SWCNTs) to image and monitor fibrin clotting in real time. Following the binding of fibrinogen to a tailored SWCNT platform, thrombin transforms the fibrinogen into fibrin monomers, which start to polymerize. The SWCNTs are incorporated within the clot and can be clearly visualized in the NIR-fluorescent channel, where the signal-to-noise ratio is improved compared to bright-field imaging in the visible range. Moreover, the diffusion of individual SWCNTs within the fibrin clot gradually slows down after the addition of thrombin, manifesting a coagulation rate that depends on both fibrinogen and thrombin concentrations. Our platform can open new opportunities for coagulation disorder diagnostics and allow for real-time monitoring of the coagulation cascade with a NIR optical signal output in the biological transparency window.

An adjoint-based method for the computation of gradients in coagulation schemes

An adjoint-based methodology is proposed to compute the gradient of the outcomes of mathematical models for the coagulation cascade. The method is first exposed and validated by considering a simple, analytically tractable case involving only 3 species. Its potential is further illustrated by considering a detailed model for the extrinsic pathway involving 34 chemical species interacting through 45 chemical reactions and for which the gradient of Endogeneous Thrombin Potential, clotting time, maximum rate and peak value of thrombin with respect to the initial concentrations and reactions rates are computed. It is shown that the method produces gradients estimates that are fully consistent with the finite differences approximation used so far in the literature, but at a much lower computational cost.

Microparticle Phosphatidylserine Mediates Coagulation: Involvement in Tumor Progression and Metastasis

Tumor progression and cancer metastasis has been linked to the release of microparticles (MPs), which are shed upon cell activation or apoptosis and display parental cell antigens, phospholipids such as phosphatidylserine (PS), and nucleic acids on their external surfaces. In this review, we highlight the biogenesis of MPs as well as the pathophysiological processes of PS externalization and its involvement in coagulation activation. We review the available evidence, suggesting that coagulation factors (mainly tissue factor, thrombin, and fibrin) assist in multiple steps of tumor dissemination, including epithelial-mesenchymal transition, extracellular matrix remodeling, immune escape, and tumor angiogenesis to support the formation of the pre-metastatic niche. Platelets are not just bystander cells in circulation but are functional players in primary tumor growth and metastasis. Tumor-induced platelet aggregation protects circulating tumor cells (CTCs) from the blood flow shear forces and immune cell attack while also promoting the binding of CTCs to endothelial cells and extravasation, which activates tumor invasion and sustains metastasis. Finally, in terms of therapy, lactadherin can inhibit coagulation by competing effectively with coagulation factors for PS binding sites and may similarly delay tumor progression. Furthermore, we also investigate the therapeutic potential of coagulation factor inhibitors within the context of cancer treatment. The development of multiple therapies targeting platelet activation and platelet-tumor cell interactions may not only reduce the lethal consequences of thrombosis but also impede tumor growth and spread.

Inhibition of thrombin on endothelium enhances recruitment of regulatory T cells during IRI and when combined with adoptive Treg transfer, significantly protects against acute tissue injury and prolongs allograft survival

Ischemia-reperfusion injury (IRI) amplifies T cell alloimmune responses after transplantation with thrombin playing a key pro-inflammatory role. To explore the influence of thrombin on regulatory T cell recruitment and efficacy we used a well-established model of IRI in the native murine kidney. Administration of the cytotopic thrombin inhibitor PTL060 inhibited IRI, and by skewing expression of chemokines (reducing CCL2 and CCL3 but increasing CCL17 and CCL22) increased the infiltration of M2 macrophages and Tregs. When PTL060 was combined with infusion of additional Tregs, these effects were further amplified. To test the benefits of thrombin inhibition in a transplant model, BALB/c hearts were transplanted into B6 mice with or without perfusion with PTL060 in combination with Tregs. Thrombin inhibition or Treg infusion alone led to small increments in allograft survival. However, the combined therapy led to modest graft prolongation by the same mechanisms as in renal IRI; graft survival was accompanied by increased numbers of Tregs and anti-inflammatory macrophages, and reduced expression of pro-inflammatory cytokines. While the grafts succumbed to rejection associated with the emergence of alloantibody, these data suggest that thrombin inhibition within the transplant vasculature enhances the efficacy of Treg infusion, a therapy that is currently entering the clinic to promote transplant tolerance.

Discovery and development of Factor Xa inhibitors (2015-2022)

As a pathological coagulation process, thrombus can lead to many serious diseases, including ischemic stroke, acute myocardial infarction (AMI), acute coronary syndrome (ACS), and deep venous thrombosis (DVT). And anticoagulant drugs are one of the most effective ways to prevent and treat these diseases. Although macromolecular anticoagulant drugs such as low molecular weight heparins (LMWHs) are widely used in the clinic, their characteristics of requiring injectable use hinder their further promotion in the clinic, and the disadvantages of oral anticoagulant drugs, such as warfarin and dabigatran etexilate, which can easily cause bleeding adverse effects, are also not addressed. Factor Xa (FXa) has gained attention because it lies at the intersection of the coagulation cascade pathways, whereas subsequently introduced Factor Xa inhibitors such as rivaroxaban and apixaban, among others, have gained market popularity because of their high potency for anticoagulation and high specificity for Factor Xa when administered orally. But some of the drawbacks that these Factor Xa inhibitors have simultaneously such as fewer indications and the lack of an effective reversal drug when bleeding occurs are urgently addressed. The development of new Factor Xa inhibitors therefore becomes one means of addressing these questions. This article summarizes the small molecule Factor Xainhibitors developed from 2015 to 2022, classifies them according to their scaffolds, focuses on the analysis of their structure-activity relationships, and provides a brief assessment of them.

Model reduction of coagulation cascade based on genetic algorithm

Fibrin is an important product of the coagulation cascade, and plays an eminent role in platelet stabilization. Since coagulation cascade models typically involve the reaction kinetics of dozens of proteins, which will incur burdensome computational costs when coupled to blood flow in complex geometries, researchers often ignore this process when constructing thrombosis models. However, previous studies have shown that fundamental aspects of coagulation can be reproduced with simpler models, which motivated us to obtain a reduced-order model of fibrin generation through a systematic approach. Therefore, we introduced a semi-automatic framework to perform model-reduction of cascade reactions in this study, which consisted of two processes. Specifically, the retained protein species and cascade reactions were determined based on published studies and simulation results from the full cascade model, while the optimal reaction rates for the new cascade network were determined using a genetic algorithm. The framework has been applied to a 19-species coagulation model that triggers fibrin generation in internal fields via reactive boundaries, and a 10-species reduced-order model was obtained to reproduce the kinetics of fibrinogenesis in the full cascade model at different boundary tissue factor concentrations. This reduced-order model of fibrinogenesis would be valuable for thrombosis modeling that considers both the coagulation cascade and platelet activity. Furthermore, the framework proposed herein can also be applied to the reductions of other cascade reaction models.

D-Dimer Level Among COVID-19 Patients as Biological Mediator for Hyper Coagulation State

&lt;b&gt;Background and Objective:&lt;/b&gt; Viremia due to SARS-CoV-2 lead variety of biochemical change in the human body, which play a crucial role in the activation of the coagulation cascade causing thrombotic complications and coagulopathies. The study aimed&lt;i&gt; &lt;/i&gt;to ascertain the D-dimer level as a biological mediator in COVID-19 patients in Khartoum state and compare the results to the control group. &lt;b&gt;Materials and Methods:&lt;/b&gt; A cross-sectional study was conducted during the period of August to December, 2021, including 50 healthy patients and 50 COVID-19 patients, blood samples were collected from study groups for measurement of D-dimer level using an I Chroma device. Statistical analysis was conducted using SSPS version 21. &lt;b&gt;Results:&lt;/b&gt; This study revealed a statistically increased D-dimer level among COVID-19 patients compared with the control group (2000-10000 vs. up to 500 ng mL&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;), respectively. &lt;b&gt;Conclusion:&lt;/b&gt; Viremia induced by COVID-19 infection can cause a high D-dimer level which can lead to thrombosis event or bleeding tendency.

Identification of the Antithrombotic Mechanism of Leonurine in Adrenalin Hydrochloride-Induced Thrombosis in Zebrafish via Regulating Oxidative Stress and Coagulation Cascade

Thrombosis is a general pathological phenomenon during severe disturbances to homeostasis, which plays an essential role in cardiovascular and cerebrovascular diseases. Leonurine (LEO), isolated from Leonurus japonicus Houtt, showes a crucial role in anticoagulation and vasodilatation. However, the properties and therapeutic mechanisms of this effect have not yet been systematically elucidated. Therefore, the antithrombotic effect of LEO was investigated in this study. Hematoxylin-Eosin staining was used to detect the thrombosis of zebrafish tail. Fluorescence probe was used to detect the reactive oxygen species. The biochemical indexes related to oxidative stress (lactate dehydrogenase, malondialdehyde, superoxide dismutase and glutathione) and vasodilator factor (endothelin-1 and nitric oxide) were analyzed by specific commercial assay kits. Besides, we detected the expression of related genes (fga, fgb, fgg, pkcα, pkcβ, vwf, f2) and proteins (PI3K, phospho-PI3K, Akt, phospho-Akt, ERK, phospho-ERK FIB) related to the anticoagulation and fibrinolytic system by quantitative reverse transcription and western blot. Beyond that, metabolomic analyses were carried out to identify the expressions of metabolites associated with the anti-thrombosis mechanism of LEO. Our in vivo experimental results showed that LEO could improve the oxidative stress injury, abnormal platelet aggregation and coagulation dysfunction induced by adrenalin hydrochloride. Moreover, LEO restored the modulation of amino acids and inositol metabolites which are reported to alleviate the thrombus formation. Collectively, LEO attenuates adrenalin hydrochloride-induced thrombosis partly via modulating oxidative stress, coagulation cascade and platelet activation and amino acid and inositol metabolites.

Associations of D-Dimer with Computed Tomographic Lung Abnormalities, Serum Biomarkers of Lung Injury, and Forced Vital Capacity: MESA Lung Study

Rationale: The coagulation cascade may play a role in the pathogenesis of interstitial lung disease through increased production of thrombin and fibrin deposition. Whether circulating coagulation cascade factors are linked to lung inflammation and scarring among community-dwelling adults is unknown. Objectives: To test the hypothesis that higher baseline D-dimer concentrations are associated with markers of early lung injury and scarring. Methods: Using the MESA (Multi-Ethnic Study of Atherosclerosis) cohort (n = 6,814), we examined associations of baseline D-dimer concentrations with high attenuation areas from examination 1 (2000-2002; n = 6,184) and interstitial lung abnormalities from examination 5 computed tomographic (CT) scans (2010-2012; n = 2,227), and serum MMP-7 (matrix metalloproteinase-7) and SP-A (surfactant protein-A) from examination 1 (n = 1,098). We examined longitudinal change in forced vital capacity (FVC) from examinations 3-6 (2004-2018, n = 3,562). We used linear logistic regression and linear mixed models to examine associations and adjust for potential confounders. Results: The mean (standard deviation) age of the cohort was 62 (10) years, and the D-dimer concentration was 0.35 (0.69) ug/ml. For every 10% increase in D-dimer concentration, there was an increase in high attenuation area percentage of 0.27 (95% confidence interval (CI), 0.08-0.47) after adjustment for covariates. Associations were stronger among those older than 65 years (P values for interaction < 0.001). A 10% increase in D-dimer concentration was associated with an odds ratio of 1.05 for interstitial lung abnormalities (95% CI, 0.99-1.11). Higher D-dimer concentrations were associated with higher serum MMP-7 and a faster decline in FVC. D-dimer was not associated with SP-A. Conclusions: Higher D-dimer concentrations were associated with a greater burden of lung parenchymal abnormalities detected on CT scan, MMP-7, and FVC decline among community-dwelling adults.

Lung Epithelial Cell Transcriptional Regulation as a Factor in COVID-19-associated Coagulopathies

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly become a global pandemic. In addition to the acute pulmonary symptoms of coronavirus disease (COVID-19) (the disease associated with SARS-CoV-2 infection), pulmonary and distal coagulopathies have caused morbidity and mortality in many patients. Currently, the molecular pathogenesis underlying COVID-19-associated coagulopathies are unknown. Identifying the molecular basis of how SARS-CoV-2 drives coagulation is essential to mitigating short- and long-term thrombotic risks of sick and recovered patients with COVID-19. We aimed to perform coagulation-focused transcriptome analysis of in vitro infected primary respiratory epithelial cells, patient-derived bronchial alveolar lavage cells, and circulating immune cells during SARS-CoV-2 infection. Our objective was to identify transcription-mediated signaling networks driving coagulopathies associated with COVID-19. We analyzed recently published experimentally and clinically derived bulk or single-cell RNA sequencing datasets of SARS-CoV-2 infection to identify changes in transcriptional regulation of blood coagulation. We also confirmed that the transcriptional expression of a key coagulation regulator was recapitulated at the protein level. We specifically focused our analysis on lung tissue-expressed genes regulating the extrinsic coagulation cascade and the plasminogen activation system. Analyzing transcriptomic data of in vitro infected normal human bronchial epithelial cells and patient-derived bronchial alveolar lavage samples revealed that SARS-CoV-2 infection induces the extrinsic blood coagulation cascade and suppresses the plasminogen activation system. We also performed in vitro SARS-CoV-2 infection experiments on primary human lung epithelial cells to confirm that transcriptional upregulation of tissue factor, the extrinsic coagulation cascade master regulator, manifested at the protein level. Furthermore, infection of normal human bronchial epithelial cells with influenza A virus did not drive key regulators of blood coagulation in a similar manner as SARS-CoV-2. In addition, peripheral blood mononuclear cells did not differentially express genes regulating the extrinsic coagulation cascade or plasminogen activation system during SARS-CoV-2 infection, suggesting that they are not directly inducing coagulopathy through these pathways. The hyperactivation of the extrinsic blood coagulation cascade and the suppression of the plasminogen activation system in SARS-CoV-2-infected epithelial cells may drive diverse coagulopathies in the lung and distal organ systems. Understanding how hosts drive such transcriptional changes with SARS-CoV-2 infection may enable the design of host-directed therapeutic strategies to treat COVID-19 and other coronaviruses inducing hypercoagulation.

Host-Parasite Relationships in Porcine Ascariosis: Anticoagulant Potential of the Third Larval Stage of Ascaris suum as a Possible Survival Mechanism

Simple Summary

Ascaris suum parasitises pigs all over the world causing a disease responsible for producing reductions in weight gains and damages to several organs of the infected animals that incur huge economic losses for the swine industry. While adult worms of this parasite are located in the small intestine of the host, their larval stages migrate through the bloodstream as an evolutionary advantageous strategy within a hostile environment that confronts host responses such as blood clots formation. The aim of this work is to study the ability of A. suum larvae to inhibit blood coagulation as a possible mechanism to control blood clots formation and facilitate their migration. The results showed that these larvae inhibited host blood coagulation and possessed molecules similar to those responsible for inhibiting blood coagulation in pigs. The anticoagulant effect of A. suum larvae could constitute a potential survival mechanism for the parasite. Therefore, developing new control strategies directed at this and similar processes could avoid A. suum larval migration and the establishment of adult worms in their definitive location, which is necessary to confront the damages and economic losses produced by this parasitosis.

Abstract

In order to evade the response of their hosts, helminth parasites have evolved precise and highly regulated mechanisms, including migration strategies of the larval stages. In regard to porcine ascariosis caused by Ascaris suum, its infective third-stage larvae (AsL3) undergo a complex migratory route through the bloodstream of their host before establishing in the small intestine to reach maturation. Despite the benefits attributed to this migration, blood clots formation could compromise larvae survival. The aim of this work was to study the interaction between the cuticle and excretory/secretory antigens of AsL3 and the host coagulation cascade. Larvae were obtained after incubating and hatching A. suum eggs, after which the antigenic extracts were produced. Their ability to disrupt the coagulation cascade was studied using anticoagulation and chromogenic assays, and techniques based on electrophoresis. The obtained results showed that both antigenic extracts possessed anticoagulant potential, being able to inhibit the intrinsic, extrinsic and/or common pathways of the blood coagulation cascade as well as the activated factor X. Moreover, three A. suum serpin proteins were identified as candidates to inhibit this host coagulation factor. To the best of our knowledge, this study shows, for the first time, the anticoagulant potential of the infective larvae of A. suum, which could be used by the parasite as a mechanism to facilitate its invasion and survival in the host.

Recognition and Management of Acute Purpura Fulminans: A Case Report of a Complication of Neisseria meningitidis Bacteremia

Purpura fulminans (PF) is a rare, potentially fatal complication of disseminated intravascular coagulation that is commonly associated with severe bacterial infections such as those caused by the bacterium Neisseria meningitidis. With the advent of vaccination, meningococcal disease has become infrequent, with a reported incidence of 1 case per 100,000 people per year. PF is an even rarer phenomenon that is only found in approximately 10 to 20% of patients with meningococcal septicemia. PF can cause irreversible tissue necrosis within 48 hours and, in severe cases, death. Early recognition is crucial as PF has a mortality rate as high as 60% in patients with meningococcal disease. Prompt recognition, treatment of the underlying cause, vigorous skin care, and multispecialty collaboration are required for optimal management of PF, though morbidity and mortality remain high as there is no cure for adult PF. We present a case of acute PF in a patient who presented with septic shock secondary to Neisseria bacteremia.

Education Case: Hereditary Thrombophilia With Double Heterozygous Factor V Leiden and Factor II c.*97G>A Mutations

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.¹.

Integrating blood cell mechanics, platelet adhesive dynamics and coagulation cascade for modelling thrombus formation in normal and diabetic blood

Normal haemostasis is an important physiological mechanism that prevents excessive bleeding during trauma, whereas the pathological thrombosis especially in diabetics leads to increased incidence of heart attacks and strokes as well as peripheral vascular events. In this work, we propose a new multiscale framework that integrates seamlessly four key components of blood clotting, namely transport of coagulation factors, coagulation kinetics, blood cell mechanics and platelet adhesive dynamics, to model the development of thrombi under physiological and pathological conditions. We implement this framework to simulate platelet adhesion due to the exposure of tissue factor in a three-dimensional microchannel. Our results show that our model can simulate thrombin-mediated platelet activation in the flowing blood, resulting in platelet adhesion to the injury site of the channel wall. Furthermore, we simulate platelet adhesion in diabetic blood, and our results show that both the pathological alterations in the biomechanics of blood cells and changes in the amount of coagulation factors contribute to the excessive platelet adhesion and aggregation in diabetic blood. Taken together, this new framework can be used to probe synergistic mechanisms of thrombus formation under physiological and pathological conditions, and open new directions in modelling complex biological problems that involve several multiscale processes.

NMR-Based Structural Characterization of a Two-Disulfide-Bonded Analogue of the FXIIIa Inhibitor Tridegin: New Insights into Structure-Activity Relationships

The saliva of blood-sucking leeches contains a plethora of anticoagulant substances. One of these compounds derived from Haementeria ghilianii, the 66mer three-disulfide-bonded peptide tridegin, specifically inhibits the blood coagulation factor FXIIIa. Tridegin represents a potential tool for antithrombotic and thrombolytic therapy. We recently synthesized two-disulfide-bonded tridegin variants, which retained their inhibitory potential. For further lead optimization, however, structure information is required. We thus analyzed the structure of a two-disulfide-bonded tridegin isomer by solution 2D NMR spectroscopy in a combinatory approach with subsequent MD simulations. The isomer was studied using two fragments, i.e., the disulfide-bonded N-terminal (Lys1–Cys37) and the flexible C-terminal part (Arg38–Glu66), which allowed for a simplified, label-free NMR-structure elucidation of the 66mer peptide. The structural information was subsequently used in molecular modeling and docking studies to provide insights into the structure–activity relationships. The present study will prospectively support the development of anticoagulant-therapy-relevant compounds targeting FXIIIa.

Formation of nasal polyps: The roles of innate type 2 inflammation and deposition of fibrin

Chronic rhinosinusitis (CRS) is one of the most common chronic diseases worldwide. It is a heterogeneous disease, and geographical or ethnic differences in inflammatory pattern in nasal mucosa are major issues. Tissue eosinophilia in CRS is highly associated with extensive sinus disease, recalcitrance, and a higher nasal polyp (NP) recurrence rate after surgery. The prevalence of eosinophilic CRS (ECRS) is increasing in Asian countries within the last 2 decades, and this trend appears to be occurring across the world. International consensus criteria for ECRS are required for the accurate understanding of disease pathology and precision medicine. In a multicenter large-scale epidemiological survey, the "Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis study," ECRS was definitively defined when the eosinophil count in nasal mucosa is greater than or equal to 70 eosinophils/hpf (magnification, ×400), and this study proposed an algorithm that classifies CRS into 4 groups according to disease severity. The main therapeutic goal with ECRS is to eliminate or diminish the bulk of NP tissue. NPs are unique abnormal lesions that grow from the lining of the nasal and paranasal sinuses, and type 2 inflammation plays a critical role in NP development in patients with ECRS. An imbalance between protease and endogenous protease inhibitors might play a pivotal role in the initiation and exacerbation of type 2 inflammation in ECRS. Intraepithelial mast cells in NPs, showing a tryptase+, chymase- phenotype, may also enhance type 2 inflammation. Intense edema and reduced fibrosis are important histological features of eosinophilic NPs. Mucosal edema mainly consists of exuded plasma protein, and excessive fibrin deposition would be expected to contribute to the retention of proteins from capillaries and thereby perpetuate mucosal edema that may play an etiological role in NPs. Upregulation of the coagulation cascade and downregulation of fibrinolysis strongly induce abnormal fibrin deposition in nasal mucosa, and type 2 inflammation plays a central role in the imbalance of coagulation and fibrinolysis.

Tumor Vessel Targeted Self-Assemble Nanoparticles for Amplification and Prediction of the Embolization Effect in Hepatocellular Carcinoma

Vessel embolization is recommended as the first line treatment for unresectable hepatocellular carcinoma (HCC). However, owing to the imprecise vessel embolization and heterogeneous response performance among patients, its survival benefits are often compromised. Herein, we reported an innovative strategy to extensively embolize the tumor by triggering the coagulation cascade, and predict the embolization effect with vessel density assessment. We synthesized manganese dioxide (MnO₂)/verteporfin (BPD) nanocomposites, in which BPD bound to the tumor vessel endothelial cells (TVECs) and MnO₂ nanosheets served as the carrier. MnO₂ was reduced to Mn²⁺ ions and self-assembled with BPD to produce nanoBPD, resulting in enhanced TVECs apoptosis and coagulation cascade compared to that with free BPD. Furthermore, multimodal imaging was used to visualize tumor vessel density, which can be used as a predictor to identify the patients who would benefit from embolization. Our findings describe a promising strategy for both tumor eradication and effect prediction to improve survival benefits in unresectable HCC patients.

Platelet-Derived Factor V Is an Important Determinant of the Metastatic Potential of Circulating Tumor Cells

Factor V (FV) is a critical component in the blood coagulation cascade. In patients, FV inhibitors have been reported to be associated with malignancy. FV is present in plasma and platelets, which exhibit physical and functional differences. However, the functions of FV in cancer progression remain poorly understood. We evaluated the impact of different levels of FV in plasma and platelets on the haematogenous mouse pulmonary metastasis model to determine whether FV determines the metastatic potential of circulating tumor cells. The role of platelet-derived FV was evaluated using a murine B16F10 pulmonary metastasis model, an assay of tumor cell adhesion to endothelial cells, and western blotting. By combining genetic models and FV inhibitory antibody, the transgenic mice with lower platelet FV expression showed significant increases in metastases compared with mice with higher platelet FV expression. In vitro, labeled B16F10 melanoma cells appeared to exhibit increased adhesion to endothelial cells that were treated with lower levels of platelet FV, but not platelet-poor plasma. Furthermore, platelets from mice with lower platelet FV levels expressed TFPIα at lower levels than with mice with higher platelet FV expression. Based on these findings, platelet-derived FV contributes to haematogenous pulmonary metastasis and is associated with the regulation of tumor cell adhesion to the vessel wall.

Paroxysmal atrial fibrillation: changes in factor VIII and von Willebrand factor impose early hypercoagulability

Introduction

Paroxysmal atrial fibrillation (PAF) is a well-documented prothrombotic state that carries significant embolic risk. However, precise hemostatic changes in the very early stage of the disease are not completely studied. The aim of the study was to study von Willebrand factor (vWF) and coagulation factor VIII (FVIII) plasma levels and activity in the first hours (up to 24 h) of PAF clinical manifestation.

Material and methods

We selected consecutively 51 non-anticoagulated patients (26 men, 25 women, mean age: 59.84 ±1.60) with PAF and 52 controls (26 men, 26 women, mean age: 59.50 ±1.46 years) corresponding in gender, accompanying diseases and conducted treatment. The indicators were examined using enzyme-linked immunoassays and photometric tests.

Results

All patients were hospitalized between the 2^nd and 24^th h after the onset of arrhythmia (mean: 8.14 ±0.74 h). Higher FVIII levels (107.52 ±3.48% vs. 93.85 ±2.93%, p < 0.05) and activity (200.03 ±11.11% vs. 109.73 ±4.90%, p < 0.001) were found in the PAF group. vWF levels (178.40 ±12.95% vs. 119.53 ±6.12%, p < 0.001) and activity (200.92 ±12.45% vs. 110.80 ±5.14%, p < 0.001) were also higher. These changes did not depend on age, sex, body mass index or CHA₂DS₂-VASc score in the PAF group (p > 0.05). PAF duration was a significant predictor of increased FVIII levels and activity. Increased PAF duration was followed by increased values of the factors (r = 0.85, p < 0.001; r = 0.83, p < 0.001).

Conclusions

The results presented an activated coagulation cascade and endothelial injury, suggesting hypercoagulability still in the early hours of PAF. These changes in PAF did not correlate with CHA₂DS₂-VASc score risk factors, outlining PAF as a possible independent embolic risk factor.

Roles of the clip domains of two protease zymogens in the coagulation cascade in horseshoe crabs

The lipopolysaccharide (LPS)-triggered coagulation cascade in horseshoe crabs comprises three protease zymogens: prochelicerase C (proC), prochelicerase B (proB), and the proclotting enzyme (proCE). The presence of LPS results in autocatalytic activation of proC to α-chelicerase C, which, in turn, activates proB to chelicerase B, converting proCE to the clotting enzyme (CE). ProB and proCE contain an N-terminal clip domain, but the roles of these domains in this coagulation cascade remain unknown. Here, using recombinant proteins and kinetics and binding assays, we found that five basic residues in the clip domain of proB are required to maintain its LPS-binding activity and activation by α-chelicerase C. Moreover, an amino acid substitution at a potential hydrophobic cavity in proB's clip domain (V55A-proB) reduced both its LPS-binding activity and activation rate. WT proCE exhibited no LPS-binding activity, and the WT chelicerase B-mediated activation of a proCE variant with a substitution at a potential hydrophobic cavity (V53A-proCE) was ∼4-fold slower than that of WT proCE. The k _cat/K_m value of the interaction of WT chelicerase B with V53A-proCE was 7-fold lower than that of the WT chelicerase B-WT proCE interaction. The enzymatic activities of V55A-chelicerase B and V53A-CE against specific peptide substrates were indistinguishable from those of the corresponding WT proteases. In conclusion, the clip domain of proB recruits it to a reaction center composed of α-chelicerase C and LPS, where α-chelicerase C is ready to activate proB, leading to chelicerase B-mediated activation of proCE via its clip domain.

Exploring the efficiency of thrombin inhibitors with a quantitative model of the coagulation cascade

A detailed mathematical description of the coagulation cascade is a challenging task due to a huge set of protein-protein interactions. Simplified models do not permit quantitative description of anticoagulants. The detailed mathematical model presented here was constructed with 98 reactions between 70 species. The model was verified using experimental data on thrombin generation. Four thrombin inhibitors, which have different inhibitory mechanisms, were incorporated into the model. All four thrombin inhibitors delayed prothrombin conversion into thrombin, but did not preclude it. At high inhibitor concentration, thrombin-mediated positive feedback loops were strongly inhibited and the proportion of prothrombin, converted with factor Xa only, was considerably increased. The most potent inhibitor of prothrombin conversion was aptamer NU172, which also binds prothrombin and inhibits its conversion.

Clinicoepidemiologic Features of Chronic Spontaneous Urticaria in Patients with Elevated Plasma D-Dimer Levels versus those without It: A Case-Control Cross-Sectional Study of 100 Indian Patients

Background

Activated coagulation cascade is implicated in urticaria pathogenesis marked by high plasma D-dimer, a marker of fibrinolysis, levels correlating with high urticaria activity score (UAS) and poor therapeutic outcome.

Methods

Quantitative plasma D-dimer levels and coagulation parameters in 100 (male:female ratio 1:3) Indian patients with chronic spontaneous urticaria and age- and gender-matched healthy controls were compared. The clinicoepidemiologic features of chronic urticaria were then compared among patients with normal (≤0.2 mg/L) and elevated (≥0.3 mg/L) plasma D-dimer levels.

Results

Plasma D-dimer in 23% patients and 4% controls and prothrombin time and activated partial thromboplastin time in 63% and 5% patients, respectively, were significantly higher compared with 58% and 1% of controls, respectively. About 18 of 72 (25%) patients with high UAS of ≥16-42 were compared with 5 of 28 (17.8%) patients with UAS7 of ≤15. Patients with elevated plasma D-dimer levels had significantly more systemic symptoms (86.9% vs. 81.8%) compared with patients with normal plasma D-dimer levels.

Conclusion

A subset of patients with chronic urticaria have elevated plasma D-dimer levels and exhibit higher UAS7 and systemic symptoms that may influence long-term prognosis and therapeutic choices. Small number of patients, a cross-sectional nature of study, lack of treatment outcome measures, information on self-medication, and unavailability of specific parameters for coagulation pathway activation remain few limitations of this study.

Meta-Analysis of Factor V, Factor VII, Factor XII, and Factor XIII-A Gene Polymorphisms and Ischemic Stroke

Numerous studies examined the association between factors FV, FVII, FXII, and FXIII-A gene polymorphisms and ischemic stroke, but conclusive evidence is yet to be obtained. Thus, this meta-analysis aimed to investigate the novel association of FV rs1800595, FVII rs5742910, FXII rs1801020, and FXIII-A rs5982 and rs3024477 polymorphisms with ischemic stroke risk. A systematic review was performed on articles retrieved before June 2018. Relevant data were extracted from eligible studies and meta-analyzed using RevMan version 5.3. The strength of association between studied polymorphisms and ischemic stroke risk was calculated as odds ratios and 95% confidence intervals, by applying both fixed- and random-effect models. A total of 25 studies involving 6100 ischemic stroke patients and 9249 healthy controls were incorporated in the final meta-analysis model. Specifically, rs1800595, rs5742910, rs1801020, rs5982, and rs3024477 consisted of 673, 3668, 922, 433, and 404 cases, as well as 995, 4331, 1285, 1321, and 1317 controls, respectively. The pooled analysis indicated that there was no significant association of FV rs1800595, FVII rs5742910, FXII rs1801020, FXIII-A rs5982, and FXIII-A rs3024477 polymorphisms with ischemic stroke risk, under any genetic models (dominant, recessive, over-dominant, and allelic). The present meta-analysis concluded that FV rs1800595, FVII rs5742910, FXII rs1801020, and FXIII-A rs5982 and rs3024477 polymorphisms are not associated with ischemic stroke risk.

Gene expression profile in mouse bacterial chronic rhinosinusitis

Persistent infection in the paranasal sinuses impairs sinus drainage and leads to bacterial chronic rhinosinusitis. Greater knowledge of the key molecules in the pathology will help to clarify the pathogenesis. Study of the gene expression profile and analysis of the associated pathway is important to identify key molecules. This study investigates the expression of different genes and analyzes the key pathway in the pathological process of bacterial chronic rhinosinusitis. Bacterial chronic rhinosinusitis was induced in mice using a Merocel nasal pack inoculated with Staphylococcus aureus. Three months of mucosa samples were collected for histological and ELISA analysis, and gene expression was tested using DNA microarray. Differentially expressed genes were selected and verified for pathway analysis. The nasal mucosa of mice with chronic rhinosinusitis showed epithelial damage and lamina propria edema in extra cellular matrix with obvious mucosal inflammation. A total of 6,018 genes in bacterial chronic rhinosinusitis group were differentially expressed compared with the control. Among them, plasma, coagulation factors, urokinase plasminogen activator and urokinase receptor plasminogen activator expression were increased. Following gene ontology analysis and reverse transcription-quantitative polymerase chain reaction, coagulation cascades associated cytokines were found to be upregulated in bacterial chronic rhinosinusitis. The present results suggest that, bacterial chronic rhinosinusitis showed severe mucosal inflammation and genes differential expression in the pathogenesis. In this process, the coagulation cascades pathways were upregulated.

Current and emerging pharmacotherapy for ischemic stroke prevention in patients with atrial fibrillation

Introduction: Atrial fibrillation (AF) is associated with high morbidity and mortality rates due to thromboembolic complications, and anticoagulation is central to the management of this common arrhythmia to prevent acute thromboembolic events. The traditional anticoagulants: heparin, fondaparinux, and vitamin K antagonists (VKA, e.g. warfarin, acenocoumarol or phenprocoumin) have long served as pharmacotherapy for ischemic stroke prophylaxis. Areas covered: In this review article, the authors provide an overview on current and emerging pharmacotherapy for ischemic stroke prevention. Furthermore, they review the data from novel therapeutic targets in the coagulation cascade, and investigational anticoagulant drugs currently assessed in preclinical and clinical studies. Expert opinion: The introduction of nonvitamin K antagonist oral anticoagulants (NOACs) was an important milestone, as these drugs show relative efficacy, safety, and convenience compared to the VKAs. Nevertheless, their clinical use still has some limitations with, for example, patients with severe renal impairment and those with mechanical heart valves, high bleeding risks, lack of standard laboratory monitoring and (some) reversal agents. To overcome some of these limitations, various attempts are now underway to discover new strategies and targets via the hemostatic pathway in order to develop new coagulation inhibiting drugs.

Interference With Coagulation Cascade as a Novel Approach to Counteract Cisplatin-Induced Acute Tubular Necrosis; an Experimental Study in Rats

Coagulation system activation plays an important role in the pathophysiology of different diseases. In spite of massive research regarding cisplatin-induced nephrotoxicity, the role of coagulation cascade in such toxicity is still questionable. Here, we aim to investigate the role of activation of coagulation system in the initiation of cisplatin-induced acute renal tubular necrosis. Moreover, the role of the anticoagulant rivaroxaban against such toxicity was investigated. Briefly, animals were classified into seven groups, eight rats each. Group 1 served as normal control group, groups (2–7) received i.p. single doses of cisplatin (6 mg/kg b.w), groups (6–7) were treated with rivaroxaban (5 and 7 mg/kg b.w, p.o., respectively) 7 days before cisplatin injection and completed for 4 days. Animals in groups (2, 3, and 4) were sacrificed after 1, 2 and 3 days of cisplatin injection, respectively, while groups (1, 5, 6, and 7) were sacrificed after 4 days of cisplatin injection. Serum cystatin-c, urea, creatinine and γ-glutamyl transferase, urinary Lipocaline-2, and KIM-1 protein densities, as well as glomerular filtration rate (GFR) were assessed. Immunofluorescence examination of glomeruli fibrin and tissue factor (TF) was also performed coupled with a histopathological study. Cisplatin administration increased expression of fibrin and TF starting 24 h of cisplatin injection even before renal failure markers elevated. Leukocytosis, thrombocytopenia, and increased prothrombin time were also observed. Cisplatin also induced tubular damage evidenced by increased serum cystatin-c, urea, and creatinine with significant decrease in GFR and Gamma glutamyl transferase (GGT) activity. Rivaroxaban significantly decreased elevation of fibrin and TF with significant reduction in serum creatinine, BUN and cystatin-c levels. Rivaroxaban also significantly improved hematological markers and histological features as well. This study showed that activation of coagulation system plays an important role in the pathophysiology of cisplatin-induced acute renal tubular damage. Interference with coagulation cascade may be a promising nephroprotective strategy against chemical nephrotoxicity.

Structure of Coagulation Factor II: Molecular Mechanism of Thrombin Generation and Development of Next-Generation Anticoagulants

Coagulation factor II, or prothrombin, is a multi-domain glycoprotein that is essential for life and a key target of anticoagulant therapy. In plasma, prothrombin circulates in two forms at equilibrium, “closed” (~80%) and “open” (~20%), brokered by the flexibility of the linker regions. Its structure remained elusive until recently when our laboratory solved the first X-ray crystal structure of the zymogen locked in the predominant closed form. Because of this technical breakthrough, fascinating aspects of the biology of prothrombin have started to become apparent, and with this, novel and important questions arise. Here, we examine the significance of the “closed”/“open” equilibrium in the context of the mechanism of thrombin generation. Further, we discuss the potential translational opportunities for the development of next-generation anticoagulants that arise from this discovery. By providing a structural overview of each alternative conformation, this minireview also offers a relevant example of modern structural biology and establishes a practical workflow to elucidate the structural features of analogous clotting and complement factors.

Function of protein kinase CK2 in thrombus formation

Thrombus formation is dependent on the interaction of platelets, leukocytes and endothelial cells as well as proteins of the coagulation cascade. This interaction is tightly controlled by phospho-regulated pathways involving protein kinase CK2. A growing number of studies have demonstrated an important role of this kinase in the regulation of primary and secondary hemostasis. Inhibition of CK2 downregulates the expression of important adhesion molecules on platelets and endothelial cells, such as glycoprotein (GP)IIb/IIIa, P-selectin, von Willebrand factor and vascular cell adhesion molecule. Moreover, the reduced CK2-dependent phosphorylation of different coagulation factors prevents the conversion of fibrinogen to fibrin. Targeting these mechanisms may open the door for the development of novel anti-thrombotic therapies.

Coagulation cascade and complement system in systemic lupus erythematosus

This study was conducted to (1) characterize coagulation cascade and complement system in systemic lupus erythematosus (SLE); (2) evaluate the associations between coagulation cascade, complement system, inflammatory response and SLE disease severity; (3) test the diagnostic value of a combination of D-dimer and C4 for lupus activity. Transcriptomics, proteomics and metabolomics were performed in 24 SLE patients and 24 healthy controls. The levels of ten coagulations, seven complements and three cytokines were measured in 112 SLE patients. Clinical data were collected from 2025 SLE patients. The analysis of multi-omics data revealed the common links for the components of coagulation cascade and complement system. The results of ELISA showed coagulation cascade and complement system had an interaction effect on SLE disease severity, this effect was pronounced among patients with excess inflammation. The analysis of clinical data revealed a combination of D-dimer and C4 provided good diagnostic performance for lupus activity. This study suggested that coagulation cascade and complement system become 'partners in crime', contributing to SLE disease severity and identified the diagnostic value of D-dimer combined with C4for lupus activity.

The role of oral anticoagulant therapy in patients with acute coronary syndrome

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y₁₂ receptor antagonist represents the current standard of care to prevent atherothrombotic recurrences in patients with acute coronary syndrome (ACS). However, despite the use of DAPT, the recurrence rate of cardiovascular ischemic events still remains high. This persistent risk may be in part attributed to the sustained activation of the coagulation cascade leading to generation of thrombin, which may continue to play a key role in thrombus formation. The use of vitamin K antagonists (VKAs) as a strategy to reduce atherothrombotic recurrences after an ACS has been previously tested, leading to overall unfavorable outcomes due to the high risk of bleeding complications. The recent introduction of non-VKA oral anticoagulants (NOACs), characterized by a better safety profile and ease of use compared with VKA, has led to a reappraisal of the use of oral anticoagulant therapy for secondary prevention in ACS patients. The present article provides an overview of the rationale and prognostic role of oral anticoagulant therapy in ACS patients as well as recent updated clinical data, in particular with NOACs, in the field and future perspectives on this topic.

Antithrombotic therapy for acute coronary syndrome: Past, present and future

Plaque erosions and ruptures are the histopathological hallmarks of arterial thrombus formation in the coronary arteries. The clinical condition associated with this process is usually referred to as acute coronary syndrome (ACS). Importantly, both blood platelets and the coagulation cascade are key players for initiation, amplification and perpetuation of ACS. There has been great progress in ACS treatment in recent decades, both at the technical level of (percutaneous) revascularisation and at the level of antithrombotic treatment. Numerous trials have led to significant advancements in the development of effective anticoagulant and antiplatelet drugs. The large number of randomised controlled clinical trials (RCTs) and the huge number of patients enrolled in these RCTs, with mega trials including >10,000 patients, is unique in the history of medical research and also reflects the exceptional efforts associated with these huge research activities. The crucial issue, however, with respect to optimising treatment, relates to finding the delicate balance between the reduction of thrombotic events by effective drug treatment and the induction of bleeding that is linked to the use of potent or multiple antithrombotic agents. Interestingly, there is a gap in modern days between current guideline recommendations favouring potent platelet inhibition in ACS and the utilization of the respective drugs in clinical practice. In this review, we will summarise and discuss the past, present and future antithrombotic treatment for ACS patients with a focus on the development of optimised antiplatelet treatment strategies and their utilisation in the real world.

Inhibition of platelet aggregation and thrombosis by indole alkaloids isolated from the edible insect Protaetia brevitarsis seulensis (Kolbe)

Protaetia brevitarsis seulensis (Kolbe) has been temporarily registered as a food material by the Ministry of Food and Drug Safety of Korea (MFDS). The current study aimed to discover small antithrombotic molecules from this edible insect. Five indole alkaloids, 5‐hydroxyindolin‐2‐one (1), (1R,3S)‐1‐methyl‐1,2,3,4‐tetrahydro‐β‐carboline‐3‐carboxylic acid (2), (1S,3S)‐1‐methyl‐1,2,3,4‐tetrahydro‐β‐carboline‐3‐carboxylic acid (3), (3S)‐1,2,3,4‐tetrahydro‐β‐carboline‐3‐carboxylic acid (4) and L‐tryptophan (5), were isolated from the insect. Among them, compounds 1 and 2 prolonged aPTT and PT and impaired thrombin and FXa generation on HUVEC surface. Moreover, these compounds inhibited platelet aggregation. Antithrombotic effects of compounds 1 and 2 were further confirmed in pre‐clinical models of pulmonary embolism and arterial thrombosis. Collectively, these results demonstrated that compounds 1 and 2 could be effective antithrombotic agents and serve as new scaffolds for the development of antithrombotic drug.

Coagulation disorders and their cutaneous presentations: Pathophysiology

Hypercoagulable states are inherited or acquired predispositions to venous or arterial thromboses that are best understood in the context of the coagulation cascade. Dermatologists can play a critical role in diagnosing and treating patients with hypercoagulable states because cutaneous symptoms may be a presenting manifestation, thereby reducing morbidity and mortality related to these conditions. This review focuses on the epidemiology and pathophysiology of hypercoagulable states, while the accompanying article iterates the basic clinical features, diagnostic testing, and management of patients who have these conditions.

The relationship of circulating proteins in early pregnancy with preterm birth

BACKGROUND

Preterm birth (PTB) (< 37 completed weeks' gestation) is a pathological outcome of pregnancy and a major global health problem. Babies born preterm have an elevated risk for long-term adverse medical and neurodevelopmental sequelae. Substantial evidence implicates intrauterine infection and/or inflammation in PTB. However, these are often relatively late findings in the process, when PTB is inevitable. Identification of earlier markers of PTB may make successful intervention possible. Although select proteins, notably those related to the inflammatory pathways, have been associated with PTB, there has been a lack of research into the role of other protein pathways in the development of PTB. The purpose of this study was to investigate, using a previously described biomarker discovery approach, a subset of circulating proteins and their association with PTB focusing on samples from early pregnancy.

OBJECTIVES

The objectives of the study were as follows: (1) to perform a large-scale biomarker discovery, utilizing an innovative platform to identify proteins associated with preterm birth in plasma taken between 10 and 15 weeks' gestation and, (2) to determine which protein pathways are most strongly associated with preterm birth. To address these aims, we measured 1129 proteins in a plasma sample from early pregnancy using a multiplexed aptamer-based proteomic technology developed in Colorado by SomaLogic.

STUDY DESIGN

Using a nested case-control approach, we measured proteins at a single time point in early pregnancy in 41 women who subsequently delivered preterm and 88 women who had term uncomplicated deliveries. We measured 1129 proteins using a multiplexed aptamer-based proteomic technology developed by SomaLogic. Logistic regressions and random forests were used to compare protein levels.

RESULTS

The complement factors B and H and the coagulation factors IX and IX ab were the highest-ranking proteins distinguishing cases of preterm birth from term controls. The top 3 pathways associated with preterm birth were the complement cascade, the immune system, and the clotting cascade.

CONCLUSION

Using a discovery approach, these data provide further confirmation that there is an association of immune- and coagulation-related events in early pregnancy with preterm birth. Thus, plasma protein profiles at 10-15 weeks of gestation are related to the development of preterm birth later in pregnancy.

Quantitative Proteomics Analysis of Vitreous Humor from Diabetic Retinopathy Patients

Initial triggers for diabetic retinopathy (DR) are hyperglycemia-induced oxidative stress and advanced glycation end-products. The most pathological structural changes occur in retinal microvasculature, but the overall development of DR is multifactorial, with a complex interplay of microvascular, neurodegenerative, genetic/epigenetic, immunological, and secondary inflammation-related factors. Although several individual factors and pathways have been associated with retinopathy, a systems level understanding of the disease is lacking. To address this, we performed mass spectrometry based label-free quantitative proteomics analysis of 138 vitreous humor samples from patients with nonproliferative DR or the more severe proliferative form of the disease. Additionally, we analyzed samples from anti-VEGF (vascular endothelial growth factor) (bevacizumab)-treated patients from both groups. In our study, we identified 2482 and quantified the abundancy of 1351 vitreous proteins. Of these, the abundancy of 230 proteins was significantly higher in proliferative retinopathy compared with nonproliferative retinopathy. This specific subset of proteins was linked to inflammation, complement, and coagulation cascade proteins, protease inhibitors, apolipoproteins, immunoglobulins, and cellular adhesion molecules, reflecting the multifactorial nature of the disease. The identification of the key molecules of the disease is critical for the development of new therapeutic molecules and for the new use of existing drugs.

Modulation of the Coagulation Cascade Using Aptamers

As a novel class of therapeutics, aptamers, or nucleic acid ligands, have garnered clinical interest because of the ease of isolating a highly specific aptamer against a wide range of targets, their chemical flexibility and synthesis, and their inherent ability to have their function reversed. The following review details the development and molecular mechanisms of aptamers targeting specific proteases in the coagulation cascade. The ability of these anticoagulant aptamers to bind to and inhibit exosite function rather than binding within the active site highlights the importance of exosites in blocking protein function. As both exosite inhibitors and reversible agents, the use of aptamers is a promising strategy for future therapeutics.

Microparticle-associated tissue factor activity is reduced by inhibition of the complement protein 5 in Neisseria meningitidis-exposed whole blood

Neisseria meningitidis causes fulminant meningococcal sepsis with a massive activation of the coagulation and complement cascades. Bacterial cell envelope molecules from N. meningitidis, particularly lipopolysaccharide (LPS), induce tissue factor (TF) expression. In meningococcal sepsis, TF can be detected on circulating monocytes and microparticles (MPs) within the bloodstream. During infection, Nm activates C5 and C5a, which also is able to induce TF. We evaluated the effect of eculizumab, a C5-blocking monoclonal antibodies (mAb), on cell- and MP-associated TF. Using a lepirudin-anticoagulated whole blood model, we activated the coagulation and complement cascades by N. meningitidis, and investigated the interaction between the cascade systems with special focus on cell-associated TF-expression (mRNA and protein) and MP-associated TF-dependent thrombin and fibrin generation in platelet-free plasma. We also examined the ability of TF-positive MPs to support clot formation in whole blood. In addition, the effect of corn trypsin inhibitor and time-dependent changes on MP-associated functional TF activity was examined. Inhibition of C5 reduced cell-associated TF expression at both gene and protein level, and reduced MP-associated TF-dependent thrombin and fibrin generation in platelet-poor plasma, MP-induced TF-dependent clot formation in whole blood, implying that the complement and coagulation cascades are interplayers in N. meningitidis-mediated activation of these cascades.

Anticoagulant activities of piperlonguminine in vitro and in vivo

Piperlonguminine (PL), an important component of Piper longum fruits, is known to exhibit anti-hyperlipidemic, anti-platelet and anti-melanogenic activities. Here, the anticoagulant activities of PL were examined by monitoring activated-partial-thromboplastin-time (aPTT), prothrombin-time (PT), and the activities of thrombin and activated factor X (FXa). The effects of PL on the expressions of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were also tested in tumor necrosis factor-α (TNF-α) activated HUVECs. The results showed that PL prolonged aPTT and PT significantly and inhibited the activities of thrombin and FXa. PL inhibited the generation of thrombin and FXa in HUVECs. In accordance with these anticoagulant activities, PL prolonged in vivo bleeding time and inhibited TNF-α induced PAI-1 production. Furthermore, PAI-1/t-PA ratio was significan- tly decreased by PL. Collectively, our results suggest that PL possesses antithrombotic activities and that the current study could provide bases for the development of new anticoagulant agents.

Increased expression of factor XIII-A in patients with chronic rhinosinusitis with nasal polyps

BACKGROUND

Profound edema or formation of a pseudocyst containing plasma proteins is a prominent characteristic of nasal polyps (NP). However, the mechanisms underlying NP retention of plasma proteins in the submucosa remain unclear. Recently, we reported that impairment of fibrinolysis causes excessive fibrin deposition in NP and this might be involved in the retention of plasma proteins. Although the coagulation cascade plays a critical role in fibrin clot formation at extravascular sites, the expression and role of coagulation factors in NP remain unclear.

OBJECTIVE

The objective of this study was to investigate the expression of coagulation factors in patients with chronic rhinosinusitis (CRS).

METHODS

Sinonasal tissues were collected from patients with CRS and control subjects. We assayed mRNA for factor XIII-A (FXIII-A) by using real-time PCR and measured FXIII-A protein by means of ELISA, immunohistochemistry, and immunofluorescence.

RESULTS

FXIII-A mRNA levels were significantly increased in NP tissue from patients with CRS with NP (P < .001) compared with uncinate tissue from patients with CRS or control subjects. Similarly, FXIII-A protein levels were increased in NP. Immunofluorescence analysis revealed that FXIII-A expression in inflammatory cells and FXIII-A(+) cell numbers were significantly increased in NP. Most FXIII-A staining was observed within CD68(+)/CD163(+) M2 macrophages in NP. Levels of FXIII-A correlated with markers of M2 macrophages, suggesting that M2 macrophages are major FXIIIA-producing cells in NP.

CONCLUSION

Overproduction of FXIII-A by M2 macrophages might contribute to the excessive fibrin deposition in the submucosa of NP, which might contribute to the tissue remodeling and pathogenesis of CRS with NP.

Newly diagnosed congenital factor VII deficiency and utilization of recombinant activated factor VII (NovoSeven(®))

This case report presents a newly diagnosed congenital factor VII deficiency treated with recombinant activated factor VII (rFVIIa). Congenital factor VII deficiency is a rare autosomal-recessive bleeding disorder that occurs in fewer than 1/500,000 persons. Its presentation can vary from epistaxis to hemarthroses and severe central nervous system bleeding, and correlates poorly with factor VII levels. Our patient had not had a significant hemostatic challenge prior to his presentation and therefore never had any symptomatology suggestive of this disease. He was treated with rFVIIa, and was able to undergo repair of his fractures without bleeding.