47 research outputs found
До питання фольклоризму та фольклоризації творчості трудових мігрантів
The topicality of the research is caused by the lack of study of creative activities of the Ukrainians who are hunting for a job abroad. Prose, poetry, small genres are not the object of the thorough research yet. At the same time folkloristic processes flow lively among this group of people. This thought is proved by author’s own fieldwork. Dramatic peculiarities of migrants’ creativity (homesickness, loneliness, nostalgia) help laborers to bear their lives. Some of the bright examples of migrant folklore (poems, jokes, and a vocabulary) are given in the article as well
In Vitro Erythropoiesis at Different pO2 Induces Adaptations That Are Independent of Prior Systemic Exposure to Hypoxia
Hypoxia is associated with increased erythropoietin (EPO) release to drive erythropoiesis.
At high altitude, EPO levels first increase and then decrease, although erythropoiesis remains elevated
at a stable level. The roles of hypoxia and related EPO adjustments are not fully understood, which
has contributed to the formulation of the theory of neocytolysis. We aimed to evaluate the role
of oxygen exclusively on erythropoiesis, comparing in vitro erythroid differentiation performed
at atmospheric oxygen, a lower oxygen concentration (three percent oxygen) and with cultures of
erythroid precursors isolated from peripheral blood after a 19-day sojourn at high altitude (3450 m).
Results highlight an accelerated erythroid maturation at low oxygen and more concave morphology
of reticulocytes. No differences in deformability were observed in the formed reticulocytes in the
tested conditions. Moreover, hematopoietic stem and progenitor cells isolated from blood affected by
hypoxia at high altitude did not result in different erythroid development, suggesting no retention of a
high-altitude signature but rather an immediate adaptation to oxygen concentration. This adaptation
was observed during in vitro erythropoiesis at three percent oxygen by a significantly increased
glycolytic metabolic profile. These hypoxia-induced effects on in vitro erythropoiesis fail to provide
an intrinsic explanation of the concept of neocytolysis
In Vitro Erythropoiesis at Different pO2 Induces Adaptations That Are Independent of Prior Systemic Exposure to Hypoxia
Hypoxia is associated with increased erythropoietin (EPO) release to drive erythropoiesis. At high altitude, EPO levels first increase and then decrease, although erythropoiesis remains elevated at a stable level. The roles of hypoxia and related EPO adjustments are not fully understood, which has contributed to the formulation of the theory of neocytolysis. We aimed to evaluate the role of oxygen exclusively on erythropoiesis, comparing in vitro erythroid differentiation performed at atmospheric oxygen, a lower oxygen concentration (three percent oxygen) and with cultures of erythroid precursors isolated from peripheral blood after a 19-day sojourn at high altitude (3450 m). Results highlight an accelerated erythroid maturation at low oxygen and more concave morphology of reticulocytes. No differences in deformability were observed in the formed reticulocytes in the tested conditions. Moreover, hematopoietic stem and progenitor cells isolated from blood affected by hypoxia at high altitude did not result in different erythroid development, suggesting no retention of a high-altitude signature but rather an immediate adaptation to oxygen concentration. This adaptation was observed during in vitro erythropoiesis at three percent oxygen by a significantly increased glycolytic metabolic profile. These hypoxia-induced effects on in vitro erythropoiesis fail to provide an intrinsic explanation of the concept of neocytolysis
Variant mapping using mass spectrometry–based proteotyping as a diagnostic tool in von Willebrand disease
Background: von Willebrand disease (VWD) is the most common inherited bleeding disorder, characterized by either partial or complete von Willebrand factor (VWF) deficiency or by the occurrence of VWF proteoforms of altered functionality. The gene encoding VWF is highly polymorphic, giving rise to a variety of proteoforms with varying plasma concentrations and clinical significance. Objectives: To address this complexity, we translated genomic variation in VWF to corresponding VWF proteoforms circulating in blood. Methods: VWF was characterized in VWD patients (n = 64) participating in the Willebrand in the Netherlands study by conventional laboratory testing, DNA sequencing and complementary discovery, and targeted mass spectrometry–based plasma proteomic strategies. Results: Unbiased plasma profiling combined with immune enrichment of VWF verified VWF and its binding partner factor VIII as key determinants of VWD and revealed a remarkable heterogeneity in VWF amino acid sequence coverage among patients. Subsequent VWF proteotyping enabled identification of both polymorphisms (eg, p.Thr789Ala, p.Gln852Arg, and p.Thr1381Ala), as well as pathogenic variants (n = 16) along with their corresponding canonical sequences. Targeted proteomics using stable isotope–labeled peptides confirmed unbiased proteotyping for 5 selected variants and suggested differential proteoform quantities in plasma. The variant-to-wild-type peptide ratio was determined in 6 type 2B patients heterozygous for p.Arg1306Trp, confirming the relatively low proteoform concentration of the pathogenic variant. The elevated VWF propeptide/VWF ratio indicated increased clearance of specific VWF proteoforms. Conclusion: This study highlights how VWF proteotyping from plasma could be the first step to bridge the gap between genotyping and functional testing in VWD.</p
Absence of COVID-19-associated changes in plasma coagulation proteins and pulmonary thrombosis in the ferret model
BACKGROUND: Many patients who are diagnosed with coronavirus disease 2019 (COVID-19) suffer from venous thromboembolic complications despite the use of stringent anticoagulant prophylaxis. Studies on the exact mechanism(s) underlying thrombosis in COVID-19 are limited as animal models commonly used to study venous thrombosis pathophysiology (i.e. rats and mice) are naturally not susceptible to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Ferrets are susceptible to SARS-CoV-2 infection, successfully used to study virus transmission, and have been previously used to study activation of coagulation and thrombosis during influenza virus infection. OBJECTIVES: This study aimed to explore the use of (heat-inactivated) plasma and lung material from SARS-CoV-2-inoculated ferrets studying COVID-19-associated changes in coagulation and thrombosis. MATERIAL AND METHODS: Histology and longitudinal plasma profiling using mass spectrometry-based proteomics approach was performed. RESULTS: Lungs of ferrets inoculated intranasally with SARS-CoV-2 demonstrated alveolar septa that were mildly expanded by macrophages, and diffuse interstitial histiocytic pneumonia. However, no macroscopical or microscopical evidence of vascular thrombosis in the lungs of SARS-CoV-2-inoculated ferrets was found. Longitudinal plasma profiling revealed minor differences in plasma protein profiles in SARS-CoV-2-inoculated ferrets up to 2 weeks post-infection. The majority of plasma coagulation factors were stable and demonstrated a low coefficient of variation. CONCLUSIONS: We conclude that while ferrets are an essential and well-suited animal model to study SARS-CoV-2 transmission, their use to study SARS-CoV-2-related changes relevant to thrombotic disease is limited
The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2
Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701
Novel Role for Galectin-8 Protein as Mediator of Coagulation Factor V Endocytosis by Megakaryocytes
Galectin-8 (Gal8) interacts with beta-galactoside-containing glycoproteins and has recently been implicated to play a role in platelet activation. It has been suggested that Gal8 may also interact with platelet coagulation factor V (FV). This indispensable cofactor is stored in alpha-granules of platelets via a poorly understood endocytic mechanism that only exists in megakaryocytes (platelet precursor cells). In this study, we now assessed the putative role of Gal8 for FV biology. Surface plasmon resonance analysis and a solid phase binding assay revealed that Gal8 binds FV. The data further show that beta-galactosides block the interaction between FV and Gal8. These findings indicate that Gal8 specifically interacts with FV in a carbohydrate-dependent manner. Confocal microscopy studies and flow cytometry analysis demonstrated that megakaryocytic DAMI cells internalize FV. Flow cytometry showed that these cells express Gal8 on their cell surface. Reducing the functional presence of Gal8 on the cells either by an anti-Gal8 antibody or by siRNA technology markedly impaired the endocytic uptake of FV. Compatible with the apparent role of Gal8 for FV uptake, endocytosis of FV was also affected in the presence of beta-galactosides. Strikingly, thrombopoietin-differentiated DAMI cells, which represent a more mature megakaryocytic state, not only lose the capacity to express cell-surface bound Gal8 but also lose the ability to internalize FV. Collectively, our data reveal a novel role for the tandem repeat Gal8 in promoting FV endocytosi
Missing regions within the molecular architecture of human fibrin clots structurally resolved by XL-MS and integrative structural modeling
Upon activation, fibrinogen forms large fibrin biopolymers that coalesce into clots which assist in wound healing. Limited insights into their molecular architecture, due to the sheer size and the insoluble character of fibrin clots, have restricted our ability to develop novel treatments for clotting diseases. The, so far resolved, disparate structural details have provided insights into linear elongation; however, molecular details like the C-terminal domain of the α-chain, the heparin-binding domain on the β-chain, and other functional domains remain elusive. To illuminate these dark areas, we applied cross-linking mass spectrometry (XL-MS) to obtain biochemical evidence in the form of over 300 distance constraints and combined this with structural modeling. These restraints additionally define the interaction network of the clots and provide molecular details for the interaction with human serum albumin (HSA). We were able to construct the structural models of the fibrinogen α-chain (excluding two highly flexible regions) and the N termini of the β-chain, confirm these models with known structural arrangements, and map how the structure laterally aggregates to form intricate lattices together with the γ-chain. We validate the final model by mapping mutations leading to impaired clot formation. From a list of 22 mutations, we uncovered structural features for all, including a crucial role for βArg'169 (UniProt: 196) in lateral aggregation. The resulting model can potentially serve for research on dysfibrinogenemia and amyloidosis as it provides insights into the molecular mechanisms of thrombosis and bleeding disorders related to fibrinogen variants. The structure is provided in the PDB-DEV repository (PDBDEV_00000030)
A novel chemical footprinting approach identifies critical lysine residues involved in the binding of receptor-associated protein to cluster II of LDL receptor-related protein.
Tandem mass tags (TMTs) were utilized in a novel chemical footprinting approach to identify lysine residues that mediate the interaction of receptor-associated protein (RAP) with cluster II of LDL (low-density lipoprotein) receptor (LDLR)-related protein (LRP). The isolated RAP D3 domain was modified with TMT-126 and the D3 domain-cluster II complex with TMT-127. Nano-LC-MS analysis revealed reduced modification with TMT-127 of peptides including Lys(256), Lys(270) and Lys(305)-Lys(306) suggesting that these residues contribute to cluster II binding. This agrees with previous findings that Lys(256) and Lys(270) are critical for binding cluster II sub-domains [Fisher, Beglova and Blacklow (2006) Mol. Cell 22, 277-283]. Cluster II-binding studies utilizing D3 domain variants K(256)A, K(305)A and K(306)A now showed that Lys(306) contributes to cluster II binding as well. For full-length RAP, we observed that peptides including Lys(60), Lys(191), Lys(256), Lys(270) and Lys(305)-Lys(306) exhibited reduced modification with TMT in the RAP-cluster II complex. Notably, Lys(60) has previously been implicated to mediate D1 domain interaction with cluster II. Our results suggest that also Lys(191) of the D2 domain contributes to cluster II binding. Binding studies employing the RAP variants K(191)A, K(256)A, K(305)A and K(306)A, however, revealed a modest reduction in cluster II binding for the K(256)A variant only. This suggests that the other lysine residues can compensate for the absence of a single lysine residue for effective complex assembly. Collectively, novel insight has been obtained into the contribution of lysine residues of RAP to cluster II binding. In addition, we propose that TMTs can be utilized to identify lysine residues critical for protein complex formation
A novel chemical footprinting approach identifies critical lysine residues involved in the binding of receptor-associated protein to cluster II of LDL receptor-related protein.
Tandem mass tags (TMTs) were utilized in a novel chemical footprinting approach to identify lysine residues that mediate the interaction of receptor-associated protein (RAP) with cluster II of LDL (low-density lipoprotein) receptor (LDLR)-related protein (LRP). The isolated RAP D3 domain was modified with TMT-126 and the D3 domain-cluster II complex with TMT-127. Nano-LC-MS analysis revealed reduced modification with TMT-127 of peptides including Lys(256), Lys(270) and Lys(305)-Lys(306) suggesting that these residues contribute to cluster II binding. This agrees with previous findings that Lys(256) and Lys(270) are critical for binding cluster II sub-domains [Fisher, Beglova and Blacklow (2006) Mol. Cell 22, 277-283]. Cluster II-binding studies utilizing D3 domain variants K(256)A, K(305)A and K(306)A now showed that Lys(306) contributes to cluster II binding as well. For full-length RAP, we observed that peptides including Lys(60), Lys(191), Lys(256), Lys(270) and Lys(305)-Lys(306) exhibited reduced modification with TMT in the RAP-cluster II complex. Notably, Lys(60) has previously been implicated to mediate D1 domain interaction with cluster II. Our results suggest that also Lys(191) of the D2 domain contributes to cluster II binding. Binding studies employing the RAP variants K(191)A, K(256)A, K(305)A and K(306)A, however, revealed a modest reduction in cluster II binding for the K(256)A variant only. This suggests that the other lysine residues can compensate for the absence of a single lysine residue for effective complex assembly. Collectively, novel insight has been obtained into the contribution of lysine residues of RAP to cluster II binding. In addition, we propose that TMTs can be utilized to identify lysine residues critical for protein complex formation