UNASSIGNED: Intravenous plasminogen replacement therapy for patients with plasminogen deficiency type 1 (hypoplasminogenemia) was recently approved for marketing in the US. In this case report, the authors describe a 33-year-old man with hypoplasminogenemia who developed nonhealing postsurgical wounds following trauma to his right hand despite receiving standard treatment for 4 months. The patient was enrolled in a compassionate-use protocol with intravenous plasminogen replacement therapy and experienced prompt resolution of surgical wounds. He was the first human patient to receive replacement therapy with plasminogen, human-tvmh in the US and first to demonstrate cutaneous wound healing in addition to resolution of ligneous lesions attributable to plasminogen deficiency type 1.

Burkitt\'s lymphoma (BL) is a rare and highly aggressive B-cell non-Hodgkin lymphoma. Although the outcomes of patients with BL have greatly improved, options for patients with relapsed and refractory BL are limited. Therefore, there is an urgent need to improve BL therapeutics and to develop novel drugs with reduced toxicity. In this study, we demonstrated that enolase 1 (ENO1) is a potential novel drug target for BL treatment. We determined that ENO1 was aberrantly upregulated in BL, which was closely related to its invasiveness and poor clinical outcomes. Furthermore, using RNA interference, we demonstrated that ENO1 depletion significantly inhibited cell proliferation and invasion both in vitro and in vivo. Mechanistically, we established that ENO1 knockdown suppressed the PI3K-AKT and epithelial-mesenchymal transition (EMT) signaling pathways by reducing plasminogen (PLG) recruitment, plasmin (PL) generation, and TGF-β1 activation. Addition of activated TGF-β1 protein to the culture medium of shENO1 cells reversed the inhibitory effects on cell proliferation and invasion, as well as those on the PI3K-AKT and EMT signaling pathways. Notably, our research led to the discovery of a novel ENO1-PLG interaction inhibitor, Ciwujianoside E (L-06). L-06 effectively disrupts the interaction between ENO1 and PLG, consequently reducing PL generation and suppressing TGF-β1 activation. In both in vitro and in vivo experiments, L-06 exerted impressive antitumor effects. In summary, our study elucidated the critical role of ENO1 in BL cell proliferation and invasion and introduced a novel ENO1 inhibitor, which holds promise for improving the treatment of patients with BL in the future.

Acute hypoxemic respiratory failure (AHRF) is defined as acute and progressive, and patients are at a greater risk of developing acute respiratory distress syndrome (ARDS). Until now, most studies have focused on prognostic and diagnostic biomarkers in ARDS. Since there is evidence supporting a connection between dysregulated coagulant and fibrinolytic pathways in ARDS progression, it is plausible that this dysregulation also exists in AHRF. The aim of this study was to explore whether levels of soluble endothelial protein C receptor (sEPCR) and plasminogen differentiate patients admitted to the emergency department (ED) with AHRF. sEPCR and plasminogen levels were measured in 130 AHRF patients upon ED presentation by ELISA. Our results demonstrated that patients presenting to the ED with AHRF had elevated levels of sEPCR and plasminogen. It seems that dysregulation of coagulation and fibrinolysis occur in the early stages of respiratory failure requiring hospitalisation. Further research is needed to fully comprehend the contribution of sEPCR and plasminogen in AHRF.

Plasminogen (Pg) is currently considered a master regulator of wound healing, but the molecular mechanisms of its efficacy in improving impaired closure of chronic skin ulcers in type 2 diabetes patients remain unclear. Here, we investigated wound healing effects of autologous plasma-derived Pg in diabetes patients with chronic foot ulcers and evaluated Pg-induced changes in levels of key protein markers related to wound repair. Type 2 diabetes patients with chronic wounds of lower extremities were included in the study and received topical applications of Pg in a dose of 1.0 mg/mL every 2 days during 20 days, in addition to the standard wound management treatment. Patients treated only according to conventional protocol served as a control. Wound closure rates were monitored by digital planimetry of wound areas. Plasminogen supplementary treatment significantly accelerated relative wound closure as compared with diabetes patients from the control group (24 ± 4 days vs 120 ± 17 days, respectively, P < .01). As shown by Western blot, Pg application reduced expression of protein regulators of hypoxia events, angiogenesis, and autophagy such as hypoxia-inducible factor-1α (by 6.3-folds, P < .01), angiostatins (by 2.5-folds, P < .05), and autophagy marker LC3-II/LC3-I (by 8.6-folds, P < .05), while increasing vascular endothelial growth factor level by 1.9-folds (P < .05). Gelatin zymography showed that Pg-supplemented therapy decreased activity of matrix metalloproteinase-9 (MMP-9) by 3.5-folds at the end of treatment period (P < .01). We report here for the first time that topically applied plasma-derived Pg has a pronounced beneficial effect in promoting foot ulcer healing in patients with type 2 diabetes through preventing hypoxia-induced signaling, reducing autophagy flux, diminishing excessive MMP activity, and enhancing angiogenesis.

The potent angiogenesis inhibitor known as human plasminogen Kringle 5 has shown promise in the treatment of vascular disorders and malignancies. The study aimed to investigate the recognition and interaction between Kringle 5 and the A2M domain of human complement component C5 using bio-specific methodologies and molecular dynamics (MD) simulation. Initially, the specific interaction between Kringle 5 and A2M was confirmed and characterized through Ligand Blot and ELISA, yielding the dissociation constant (Kd) of 1.70 × 10-7 mol/L. Then, Kringle 5 showcased a dose-dependent inhibition of the production of C5a in lung cancer A549 cells, consequently impeding their proliferation and migration. Following the utilization of frontal affinity chromatography (FAC), it was revealed that there exists a singular binding site with the binding constant (Ka) of 3.79 × 105 L/mol. Following the implementation of homology modeling and MD optimization, the detailed results indicate that only a specific segment of the N-terminal structure of the A2M molecule engages in interaction with Kringle 5 throughout the binding process and the principal driving forces encompass electrostatic force, hydrogen bonding, and van der Waals force. In conclusion, the A2M domain of human complement C5 emerges as a plausible binding target for Kringle 5 in vivo.

The pivotal role of human endometrial stromal cells (hESCs) in the development of endometriosis lies in their ability to adopt a pro-invasive and proinflammatory profile upon migration to areas outside the uterus. However, the molecular mechanisms involved in these events remain unclear. In this study, we investigated how angiotensin II (Ang II) affects the plasminogen-plasmin system in hESCs, and the mechanisms underlying cell proliferation, migration, matrix degradation, and inflammation. Precursors, receptors, and peptidases involved in angiotensin metabolism increased significantly in Ang II-treated hESCs. The expression and activity of tissue (tPA)- and urokinase (uPA)- type plasminogen activators and the receptor for uPA (uPAR) were induced in the presence of Ang II. The up-regulation of tPA-uPA/uPAR pathway significantly contributes to heightened plasmin production both on the surface of hESCs and in their conditioned media. As a result, the plasmin generation induced by Ang II enhances the degradation of fibrin and matrix proteins, while also boosting hESC viability, proliferation, and migration through the up-regulation of growth factor expression. Notably, Ang II-induced hESC migration was dependent on the generation of active plasmin on cell surface. Ang II regulates oxidative and inflammatory signalling in hESCs primarily via NADPH oxidase and through the up-regulation of proinflammatory cytokines and adhesion molecules. Interestingly, Ang II receptor (AT1R) blockage, decreased plasmin generation, tPA-uPA/uPAR expression and hESC migration. Our results suggest that Ang II/AT1R axis regulates hESC proliferation and migration through tPA-uPA/uPAR pathway activation and plasmin generation. We propose the Ang II/AT1R axis as a potential target for endometriosis treatment.

UNASSIGNED: Relapsing fever (RF) remains a neglected human disease that is caused by a number of diverse pathogenic Borrelia (B.) species. Characterized by high cell densities in human blood, relapsing fever spirochetes have developed plentiful strategies to avoid recognition by the host defense mechanisms. In this scenario, spirochetal lipoproteins exhibiting multifunctional binding properties in the interaction with host-derived molecules are known to play a key role in adhesion, fibrinolysis and complement activation.
UNASSIGNED: Binding of CihC/FbpC orthologs to different human proteins and conversion of protein-bound plasminogen to proteolytic active plasmin were examined by ELISA. To analyze the inhibitory capacity of CihC/FbpC orthologs on complement activation, a microtiter-based approach was performed. Finally, AlphaFold predictions were utilized to identified the complement-interacting residues.
UNASSIGNED: Here, we elucidate the binding properties of CihC/FbpC-orthologs from distinct RF spirochetes including B. parkeri, B. hermsii, B. turicatae, and B. recurrentis to human fibronectin, plasminogen, and complement component C1r. All CihC/FbpC-orthologs displayed similar binding properties to fibronectin, plasminogen, and C1r, respectively. Functional studies revealed a dose dependent binding of plasminogen to all borrelial proteins and conversion to active plasmin. The proteolytic activity of plasmin was almost completely abrogated by tranexamic acid, indicating that lysine residues are involved in the interaction with this serine protease. In addition, a strong inactivation capacity toward the classical pathway could be demonstrated for the wild-type CihC/FbpC-orthologs as well as for the C-terminal CihC fragment of B. recurrentis. Pre-incubation of human serum with borrelial molecules except CihC/FbpC variants lacking the C-terminal region protected serum-susceptible Borrelia cells from complement-mediated lysis. Utilizing AlphaFold2 predictions and existing crystal structures, we mapped the putative key residues involved in C1r binding on the CihC/FbpC orthologs attempting to explain the relatively small differences in C1r binding affinity despite the substitutions of key residues. Collectively, our data advance the understanding of the multiple binding properties of structural and functional highly similar molecules of relapsing fever spirochetes proposed to be involved in pathogenesis and virulence.

Lipoprotein(a) (Lp(a)), an independent, causal cardiovascular risk factor, is a lipoprotein particle that is formed by the interaction of a low-density lipoprotein (LDL) particle and apolipoprotein(a) (apo(a))1,2. Apo(a) first binds to lysine residues of apolipoprotein B-100 (apoB-100) on LDL through the Kringle IV (KIV) 7 and 8 domains, before a disulfide bond forms between apo(a) and apoB-100 to create Lp(a) (refs. 3-7). Here we show that the first step of Lp(a) formation can be inhibited through small-molecule interactions with apo(a) KIV7-8. We identify compounds that bind to apo(a) KIV7-8, and, through chemical optimization and further application of multivalency, we create compounds with subnanomolar potency that inhibit the formation of Lp(a). Oral doses of prototype compounds and a potent, multivalent disruptor, LY3473329 (muvalaplin), reduced the levels of Lp(a) in transgenic mice and in cynomolgus monkeys. Although multivalent molecules bind to the Kringle domains of rat plasminogen and reduce plasmin activity, species-selective differences in plasminogen sequences suggest that inhibitor molecules will reduce the levels of Lp(a), but not those of plasminogen, in humans. These data support the clinical development of LY3473329-which is already in phase 2 studies-as a potent and specific orally administered agent for reducing the levels of Lp(a).

BACKGROUND: Complex pleural space infections often require treatment with multiple doses of intrapleural tissue plasminogen activator (tPA) and deoxyribonuclease, with treatment failure frequently necessitating surgery. Pleural infections are rich in neutrophils, and neutrophil elastase degrades plasminogen, the target substrate of tPA, that is required to generate fibrinolysis. We hypothesized that pleural fluid from patients with pleural space infection would show high elastase activity, evidence of inflammatory plasminogen degradation, and low fibrinolytic potential in response to tPA that could be rescued with plasminogen supplementation.
OBJECTIVE: Does neutrophil elastase degradation of plasminogen contribute to intrapleural fibrinolytic failure?
METHODS: We obtained infected pleural fluid and circulating plasma from hospitalized adults (n = 10) with institutional review board approval from a randomized trial evaluating intrapleural fibrinolytics vs surgery for initial management of pleural space infection. Samples were collected before the intervention and on days 1, 2, and 3 after the intervention. Activity assays, enzyme-linked immunosorbent assays, and Western blot analysis were performed, and turbidimetric measurements of fibrinolysis were obtained from pleural fluid with and without exogenous plasminogen supplementation. Results are reported as median (interquartile range) or number (percentage) as appropriate, with an α value of 0.05.
RESULTS: Pleural fluid elastase activity was more than fourfold higher (P = .02) and plasminogen antigen levels were more than threefold lower (P = .04) than their corresponding plasma values. Pleural fluid Western blot analysis demonstrated abundant plasminogen degradation fragments consistent with elastase degradation patterns. We found that plasminogen activator inhibitor 1 (PAI-1), the native tPA inhibitor, showed high antigen levels before the intervention, but the overwhelming majority of this PAI-1 (82%) was not active (P = .003), and all PAI-1 activity was lost by day 2 after the intervention in patients receiving intrapleural tPA and deoxyribonuclease. Finally, using turbidity clot lysis assays, we found that the pleural fluid of 9 of 10 patients was unable to generate a significant fibrinolytic response when challenged with tPA and that plasminogen supplementation rescued fibrinolysis in all patients.
CONCLUSIONS: Inflammatory plasminogen deficiency, not high PAI-1 activity, is a significant contributor to intrapleural fibrinolytic failure.
BACKGROUND: ClinicalTrials.gov; No.: NCT03583931; URL: www.
RESULTS: gov.

Histone H2B is a member of the core histones, which together with other histones form the nucleosome, the basic structural unit of chromosomes. As scientists delve deeper into histones, researchers gradually realize that histone H2B is not only an important part of nucleosomes, but also plays a momentous role in regulating gene transcription, acting as a receptor and antimicrobial action outside the nucleus. There are a variety of epigenetically modified sites in the H2B tail rich in arginine and lysine, which can occur in ubiquitination, phosphorylation, methylation, acetylation, etc. When stimulated by foreign factors such as bacteria, viruses or parasites, histone H2B can act as a receptor for the recognition of these pathogens, and induce an intrinsic immune response to enhance host defense. In addition, the extrachromosomal histone H2B is also an important anti-microorganism agent, which may be the key to the development of antibiotics in the future. This review aims to summarize the interaction between histone H2B and etiological agents and explore the role of H2B in epigenetic modifications, receptors and antimicrobial activity.