Project description:The cells and mechanisms involved in blood clot resorption are only partially known. Regulatory T cells (Treg) accumulate in venous blood clots and regulate thrombolysis by controlling the recruitment, differentiation and matrix metalloproteinase (MMP) activity of monocytes. The clot Treg population is heterogeneous and contains a population of Treg that forms the matricellular acid- and cysteine-rich protein (SPARC). SPARC induces MMP activity in monocytes and SPARC+ Treg are required for clot resorption.
Project description:Arthropods include chelicerates, crustaceans, and insects that all have open circulation systems and thus require different properties of their coagulation system than vertebrates. Although the clotting reaction in the chelicerate horseshoe crab has been described in details, the overall protein composition of the resulting clot has not been analysed for any of the chelicerates. The largest class among the chelicerates is the arachnids, which includes spiders, ticks, mites, and scorpions. Here, we use a mass spectrometry-based approach to characterize the spider hemolymph clot proteome from the Brazilian whiteknee tarantula, Acanthoscurria geniculate. We focused on the insoluble part of the clot and demonstrated high concentrations of proteins homologous to the hemostasis-related and multimerization-prone von Willebrand factor. These proteins, which include hemolectins and vitellogenin homologous, were previously identified as essential components of the hemolymph clot in crustaceans and insects. Their presence in the spider hemolymph clot suggests that the origin of these proteins’ function in coagulation predates the split between chelicerates and mandibulata. The clot proteome reveals that the major proteinaceous component is the oxygen-transporting and phenoloxidase-displaying abundant hemolymph protein hemocyanin, suggesting that this protein also plays a role in clot biology. In general, many of the identified clot-proteins are related to the innate immune system, and our results support the previously suggested crosstalk between immunity and coagulation in arthropods.
Project description:Antiphospholipid syndrome (APS) is associated with arterial and venous thrombosis. The unfavorable fibrin clot phenotype, including formation of dense and poorly lysable clots, has been reported both in thrombotic APS and venous thromboembolism (VTE). The presence and amount of different proteins within a plasma clot, not only associated with the coagulation system, may influence clot properties. To our knowledge, there is a lack of data on plasma fibrin-clot bound proteins in patients with thrombotic APS or VTE. The aim of our study was to perform a quantitative proteomic analysis of fibrin clots prepared from citrated plasma from subjects with thrombotic APS and prior VTE, along with fibrin clot permeability (Ks) and clot lysis time (CLT) assessed ex vivo. We investigated 23 consecutive patients with APS, 18 with a history of first-ever VTE, and 20 age and sex matched healthy subjects. A multiple enzyme digestion filter aided sample preparation and a multienzyme digestion (MED) FASP method combined with LC-MS/MS analysis performed on a Proxeon Easy-nLC System coupled to the Q Exactive HF mass spectrometer were used. The proteomic analysis revealed that clot composition regarding 117 proteins in APS patients and 48 proteins in VTE patients was changed as compared to healthy controls, while 72 clot-bounded proteins differed between APS and VTE subjects. In healthy controls, Ks was associated with fibrinogen alpha and gamma chains (r=0.46 and r=0.46, both p<0.05, respectively) or apolipoprotein B-100 (r=-0.53, p<0.05), while CLT correlated with annexin A2 (r=-0.58, p<0.05), apolipoportein(a) (r=0.47, p<0.05), or platelet glycoprotein 4 (r=0.59, p<0.05). In VTE patients correlations of Ks with complement C1q and histone H2B, as factors closely linked with thrombosis, were observed (r=-0.52 and r=-0.47, both p<0.05, respectively). In patients with thrombotic APS all above-mentioned associations were not found. This study is the first to show that different proteins are able to influence the clot formation, structure, and properties. Since, prothrombotic conditions abolished associations observed in healthy subjects fibrin clots, differences in protein clot components might explain the links between prothrombotic fibrin clot phenotype and thromboembolic events.
Project description:Key pulmonary findings included: 1) Loss or damage to respiratory epithelial basal cells, alveolar epithelial cells, 2) Impaired clot fibrinolysis with increased levels of plasma and lung PAI-1, and 3) modulation of cellular senescence markers.
Project description:The presence and amount of the proteins within a plasma clot may influence clot properties, like susceptibility to fibrinolysis, however, the plasma clot proteome has not yet been extensively described. The aim of the study was to investigate the protein composition of clots prepared ex vivo from plasma of the peripheral blood of four patients with acute myocardial infarction (AMI) in two time points: in the acute ischemic phase and two months later during the standard therapy. Proteomic analysis revealed a total number of 62 proteins identified in all 8 samples grouping into several distinct functional clusters (e.g. cholesterol transporter activity, immunoglobulin binding and peptidase regulatory activity). The protein signatures of clots differed significantly depending on time after ACS, showing 30% greater variability in protein composition of the clots prepared in the plasma two months after the onset of AMI as compared to the clots generated at the time of admission to the hospital. Several proteins that could be involved in clot formation and resolution showed an interesting pattern of changes over time. For example α2-antiplasmin, which was robustly present in clots of all patients in acute phase of AMI, was detectable in lower abundance in only 2 clots prepared in plasma taken 8-12 weeks after AMI, whereas serotransferrin can be detected only in the clots prepared from plasma taken later during the therapy. In conclusion, we provided the first qualitative analysis of proteomes of fibrin clots generated ex vivo in plasma taken from patients with AMI showing differences in protein composition between clots generated in the acute ischemic phase and those prepared two months later. It might be hypothesized that differences involving several proteins of potential influence on within-clot fibrinolysis and clot stability may partially explain time-dependent changes in the clots structure and firmness in patients with AMI.
Project description:The aim of this experiment was to understand the different transcriptomic profiles of Staphylococcus aureus strains when cultured in 50% milk media with TSB media as a control. Bovine S. aureus strains that are capable of clotting milk where compared to both bovine and human S. aureus strains unable to clot milk. All strains are from sequence type 97.
Project description:Thromboembolic diseases are commonly associated with thrombus-induced ischemia and tissue damage; identification of the location of the thrombus, or thrombus-targeting, may facilitate diagnosis and target therapy. We hypothesized that aptamers with high affinity and specificity for coagulation factor XIII (FXIII) can serve as thrombus-targeting probes. With systematic evolution of ligands by exponential enrichment technology and semi-activated FXIII (FXIII’) as the target, guanine-rich FXIII’-binding aptamers (FAs; 76 nt) were selected from a library of single-stranded DNA. Next generation sequencing identified FAs with the highest frequency; bio-layer interferometry revealed a dissociation constant (Kd) from 0.7 to 2.5 nM. Truncation with preservation of a conserved region based on entropy analysis resulted in three truncated FAs (FATs; 41-47 nt) that exhibited 4-fold signal in binding to activated vs. resting platelets, as determined by flowcytometry. In addition, FAT2 exhibited up to 4.2-fold binding of that from scrambled ssDNA to platelet/fibrin clot or whole blood clot in vitro, suggesting binding to both activated plateltes and fibrin. FAT2 also exhibited targeting effects in a microcirculatory thrombosis model in mice. Nevertheless, FATs induced no effect on blood coagulation, as determined by thromboelastometry. In conclusion, FXIII-binding aptamers are potentially amenable to thrombus targeting in theranostic application of thromboembolic diseases.