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1.
Nat Commun ; 11(1): 4964, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009394

RESUMO

Thrombosis leads to platelet activation and subsequent degradation; therefore, replenishment of platelets from hematopoietic stem/progenitor cells (HSPCs) is needed to maintain the physiological level of circulating platelets. Platelet-derived microparticles (PMPs) are protein- and RNA-containing vesicles released from activated platelets. We hypothesized that factors carried by PMPs might influence the production of platelets from HSPCs, in a positive feedback fashion. Here we show that, during mouse acute liver injury, the density of megakaryocyte in the bone marrow increases following an increase in circulating PMPs, but without thrombopoietin (TPO) upregulation. In vitro, PMPs are internalized by HSPCs and drive them toward a megakaryocytic fate. Mechanistically, miR-1915-3p, a miRNA highly enriched in PMPs, is transported to target cells and suppresses the expression levels of Rho GTPase family member B, thereby inducing megakaryopoiesis. In addition, direct injection of PMPs into irradiated mice increases the number of megakaryocytes and platelets without affecting TPO levels. In conclusion, our data reveal that PMPs have a role in promoting megakaryocytic differentiation and platelet production.


Assuntos
Plaquetas/metabolismo , Diferenciação Celular , Micropartículas Derivadas de Células/metabolismo , Megacariócitos/citologia , MicroRNAs/metabolismo , Animais , Sequência de Bases , Linhagem Celular , Endocitose , Perfilação da Expressão Gênica , Humanos , Fígado/lesões , Fígado/patologia , Masculino , Megacariócitos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , MicroRNAs/genética , Poliploidia , Proteína rhoB de Ligação ao GTP/metabolismo
2.
J Hematol Oncol ; 13(1): 120, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32887634

RESUMO

BACKGROUND: Critically ill patients diagnosed with COVID-19 may develop a pro-thrombotic state that places them at a dramatically increased lethal risk. Although platelet activation is critical for thrombosis and is responsible for the thrombotic events and cardiovascular complications, the role of platelets in the pathogenesis of COVID-19 remains unclear. METHODS: Using platelets from healthy volunteers, non-COVID-19 and COVID-19 patients, as well as wild-type and hACE2 transgenic mice, we evaluated the changes in platelet and coagulation parameters in COVID-19 patients. We investigated ACE2 expression and direct effect of SARS-CoV-2 virus on platelets by RT-PCR, flow cytometry, Western blot, immunofluorescence, and platelet functional studies in vitro, FeCl3-induced thrombus formation in vivo, and thrombus formation under flow conditions ex vivo. RESULTS: We demonstrated that COVID-19 patients present with increased mean platelet volume (MPV) and platelet hyperactivity, which correlated with a decrease in overall platelet count. Detectable SARS-CoV-2 RNA in the blood stream was associated with platelet hyperactivity in critically ill patients. Platelets expressed ACE2, a host cell receptor for SARS-CoV-2, and TMPRSS2, a serine protease for Spike protein priming. SARS-CoV-2 and its Spike protein directly enhanced platelet activation such as platelet aggregation, PAC-1 binding, CD62P expression, α granule secretion, dense granule release, platelet spreading, and clot retraction in vitro, and thereby Spike protein enhanced thrombosis formation in wild-type mice transfused with hACE2 transgenic platelets, but this was not observed in animals transfused with wild-type platelets in vivo. Further, we provided evidence suggesting that the MAPK pathway, downstream of ACE2, mediates the potentiating role of SARS-CoV-2 on platelet activation, and that platelet ACE2 expression decreases following SARS-COV-2 stimulation. SARS-CoV-2 and its Spike protein directly stimulated platelets to facilitate the release of coagulation factors, the secretion of inflammatory factors, and the formation of leukocyte-platelet aggregates. Recombinant human ACE2 protein and anti-Spike monoclonal antibody could inhibit SARS-CoV-2 Spike protein-induced platelet activation. CONCLUSIONS: Our findings uncovered a novel function of SARS-CoV-2 on platelet activation via binding of Spike to ACE2. SARS-CoV-2-induced platelet activation may participate in thrombus formation and inflammatory responses in COVID-19 patients.


Assuntos
Betacoronavirus/metabolismo , Plaquetas/metabolismo , Infecções por Coronavirus/metabolismo , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/metabolismo , Trombose/metabolismo , Adulto , Idoso , Animais , Betacoronavirus/genética , Células CACO-2 , Infecções por Coronavirus/virologia , Feminino , Células HeLa , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Células PC-3 , Pandemias , Peptidil Dipeptidase A/genética , Agregação Plaquetária/imunologia , Contagem de Plaquetas , Pneumonia Viral/virologia , RNA Viral/sangue , Serina Endopeptidases/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Trombose/virologia
3.
Anticancer Res ; 40(10): 5715-5725, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988897

RESUMO

BACKGROUND/AIM: The platelet distribution width (PDW) and serum C-reactive protein (CRP) levels are known to be predictive of prognosis in various malignancies. Our aim was to determine whether combining PDW and serum CRP levels produces a prognostic indicator for esophageal cancer (EC) patients. PATIENTS AND METHODS: A total of 168 EC patients who underwent neoadjuvant therapy prior to esophagectomy were included in this study. RESULTS: We defined a combined PDW and CRP (CPC) score as follows: patients with both low pretherapeutic PDW (≤12.4 fl) and high postoperative serum CRP levels (≥0.5 mg/dl) were assigned a score of 2, while patients with one or neither of those were assigned a score of 1 or 0. A multivariable analysis showed that the CPC score was a significant risk factor for overall (p=0.006) and recurrence-free (p=0.004) survival. CONCLUSION: The CPC score is a strong prognostic indicator in EC patients.


Assuntos
Plaquetas/metabolismo , Proteína C-Reativa/metabolismo , Neoplasias Esofágicas/sangue , Prognóstico , Idoso , Plaquetas/patologia , Carcinoma de Células Escamosas , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/patologia , Esofagectomia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Recidiva Local de Neoplasia/sangue , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Fatores de Risco
4.
Int J Mol Sci ; 21(15)2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32731360

RESUMO

Along with cancer, cardiovascular and cerebrovascular diseases remain by far the most common causes of death. Heart attacks and strokes are diseases in which platelets play a role, through activation on ruptured plaques and subsequent thrombus formation. Most platelet agonists activate platelets via G protein-coupled receptors (GPCRs), which make these receptors ideal targets for many antiplatelet drugs. However, little is known about the mechanisms that provide feedback regulation on GPCRs to limit platelet activation. Emerging evidence from our group and others strongly suggests that GPCR kinases (GRKs) are critical negative regulators during platelet activation and thrombus formation. In this review, we will summarize recent findings on the role of GRKs in platelet biology and how one specific GRK, GRK6, regulates the hemostatic response to vascular injury. Furthermore, we will discuss the potential role of GRKs in thrombotic disorders, such as thrombotic events in COVID-19 patients. Studies on the function of GRKs during platelet activation and thrombus formation have just recently begun, and a better understanding of the role of GRKs in hemostasis and thrombosis will provide a fruitful avenue for understanding the hemostatic response to injury. It may also lead to new therapeutic options for the treatment of thrombotic and cardiovascular disorders.


Assuntos
Quinases de Receptores Acoplados a Proteína G/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Trombose/metabolismo , Plaquetas/metabolismo , Humanos , Ativação Plaquetária
5.
Front Immunol ; 11: 1962, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849656

RESUMO

Platelets, small anucleate cells circulating in the blood, are critical mediators in haemostasis and thrombosis. Interestingly, recent studies demonstrated that platelets contain both pro-inflammatory and anti-inflammatory molecules, equipping platelets with immunoregulatory function in both innate and adaptive immunity. In the context of infectious diseases, platelets are involved in early detection of invading microorganisms and are actively recruited to sites of infection. Platelets exert their effects on microbial pathogens either by direct binding to eliminate or restrict dissemination, or by shaping the subsequent host immune response. Reciprocally, many invading microbial pathogens can directly or indirectly target host platelets, altering platelet count or/and function. In addition, microbial pathogens can impact the host auto- and alloimmune responses to platelet antigens in several immune-mediated diseases, such as immune thrombocytopenia, and fetal and neonatal alloimmune thrombocytopenia. In this review, we discuss the mechanisms that contribute to the bidirectional interactions between platelets and various microbial pathogens, and how these interactions hold relevant implications in the pathogenesis of many infectious diseases. The knowledge obtained from "well-studied" microbes may also help us understand the pathogenesis of emerging microbes, such as SARS-CoV-2 coronavirus.


Assuntos
Betacoronavirus , Plaquetas/imunologia , Plaquetas/metabolismo , Infecções por Coronavirus/imunologia , Interações Hospedeiro-Patógeno/imunologia , Pneumonia Viral/imunologia , Imunidade Adaptativa , Infecções por Coronavirus/virologia , Hemostasia , Humanos , Imunidade Inata , Inflamação/imunologia , Pandemias , Pneumonia Viral/virologia , Trombose/metabolismo
6.
BMC Infect Dis ; 20(1): 580, 2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32762658

RESUMO

BACKGROUND: Dengue virus (DENV) causes the hospitalisation of an estimated 500,000 people every year. Outbreaks can severely stress healthcare systems, especially in rural settings. It is difficult to discriminate patients who need to be hospitalized from those that do not. Earlier work identified thrombocyte count and subsequent function as a promising prognostic marker of DENV severity. Herein, we investigated the potential of quantitative thrombocyte function tests in those admitted in the very early phase of acute DENV infections, using Multiplate™ multiple-electrode aggregometry to explore its potential in triage. METHODS: In this prospective cohort study all patients aged ≥13 admitted to Universitas Airlangga Hospital in Surabaya, Indonesia with a fever (≥38 °C) between 25 January and 1 August 2018 and with a clinical suspicion of DENV, were eligible for inclusion. Exclusion criteria were a thrombocyte count below 100 × 109/L and the use of any medication with a known anticoagulant effect, nonsteroidal anti-inflammatory drugs and acetyl salicylic acid. Clinical data was collected and blood was taken on admission, day 1 and day 7. Samples were tested for acute DENV, using Panbio NS1 ELISA. Platelet aggregation using ADP-, TRAP- and COL-test were presented as Area Under the aggregation Curve (AUC). Significance was tested between DENV+, probably DENV, fever of another origin, and healthy controls (HC). RESULTS: A total of 59 patients (DENV+ n = 10, DENV probable n = 25, fever other origin n = 24) and 20 HC were included. We found a significantly lower thrombocyte aggregation in the DENV+ group, compared with both HCs and the fever of another origin group (p < .001). Low ADP AUC values on baseline correlated to a longer hospital stay in DENV+ and probable DENV cases. CONCLUSION: Thrombocyte aggregation induced by Adenosine diphosphate, Collagen and Thrombin receptor activating peptide-6 is impaired in human DENV cases, compared with healthy controls and other causes of fever. This explorative study provides insights to thrombocyte function in DENV patients and could potentially serve as a future marker in DENV disease.


Assuntos
Plaquetas/metabolismo , Vírus da Dengue/imunologia , Dengue/diagnóstico , Dengue/epidemiologia , Sistemas Automatizados de Assistência Junto ao Leito , Testes Imediatos , Difosfato de Adenosina/sangue , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Colágeno/metabolismo , Dengue/virologia , Ensaio de Imunoadsorção Enzimática , Feminino , Febre/diagnóstico , Humanos , Indonésia/epidemiologia , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/sangue , Agregação Plaquetária , Contagem de Plaquetas , Estudos Prospectivos , Índice de Gravidade de Doença , Adulto Jovem
7.
Nat Commun ; 11(1): 4034, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32788576

RESUMO

Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency with severe platelet abnormalities and complex immunodeficiency. Although clinical gene therapy approaches using lentiviral vectors have produced encouraging results, full immune and platelet reconstitution is not always achieved. Here we show that a CRISPR/Cas9-based genome editing strategy allows the precise correction of WAS mutations in up to 60% of human hematopoietic stem and progenitor cells (HSPCs), without impairing cell viability and differentiation potential. Delivery of the editing reagents to WAS HSPCs led to full rescue of WASp expression and correction of functional defects in myeloid and lymphoid cells. Primary and secondary transplantation of corrected WAS HSPCs into immunodeficient mice showed persistence of edited cells for up to 26 weeks and efficient targeting of long-term repopulating stem cells. Finally, no major genotoxicity was associated with the gene editing process, paving the way for an alternative, yet highly efficient and safe therapy.


Assuntos
Edição de Genes , Terapia Genética , Células-Tronco Hematopoéticas/metabolismo , Síndrome de Wiskott-Aldrich/genética , Síndrome de Wiskott-Aldrich/terapia , Animais , Plaquetas/metabolismo , Sistemas CRISPR-Cas/genética , Linhagem da Célula , Códon/genética , Feminino , Loci Gênicos , Células HEK293 , Transplante de Células-Tronco Hematopoéticas , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Macrófagos/metabolismo , Masculino , Camundongos , Testes de Mutagenicidade , Células Mieloides/metabolismo , Linfócitos T/metabolismo , Síndrome de Wiskott-Aldrich/patologia , Proteína da Síndrome de Wiskott-Aldrich/genética
8.
Circulation ; 142(12): 1176-1189, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32755393

RESUMO

BACKGROUND: Severe acute respiratory syndrome corona virus 2 infection causes severe pneumonia (coronavirus disease 2019 [COVID-19]), but the mechanisms of subsequent respiratory failure and complicating renal and myocardial involvement are poorly understood. In addition, a systemic prothrombotic phenotype has been reported in patients with COVID-19. METHODS: A total of 62 subjects were included in our study (n=38 patients with reverse transcriptase polymerase chain reaction-confirmed COVID-19 and n=24 non-COVID-19 controls). We performed histopathologic assessment of autopsy cases, surface marker-based phenotyping of neutrophils and platelets, and functional assays for platelet, neutrophil functions, and coagulation tests, as well. RESULTS: We provide evidence that organ involvement and prothrombotic features in COVID-19 are linked by immunothrombosis. We show that, in COVID-19, inflammatory microvascular thrombi are present in the lung, kidney, and heart, containing neutrophil extracellular traps associated with platelets and fibrin. Patients with COVID-19 also present with neutrophil-platelet aggregates and a distinct neutrophil and platelet activation pattern in blood, which changes with disease severity. Whereas cases of intermediate severity show an exhausted platelet and hyporeactive neutrophil phenotype, patients severely affected with COVID-19 are characterized by excessive platelet and neutrophil activation in comparison with healthy controls and non-COVID-19 pneumonia. Dysregulated immunothrombosis in severe acute respiratory syndrome corona virus 2 pneumonia is linked to both acute respiratory distress syndrome and systemic hypercoagulability. CONCLUSIONS: Taken together, our data point to immunothrombotic dysregulation as a key marker of disease severity in COVID-19. Further work is necessary to determine the role of immunothrombosis in COVID-19.


Assuntos
Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Insuficiência Respiratória/etiologia , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Transtornos da Coagulação Sanguínea/diagnóstico , Transtornos da Coagulação Sanguínea/etiologia , Plaquetas/citologia , Plaquetas/metabolismo , Plaquetas/patologia , Estudos de Casos e Controles , Infecções por Coronavirus/complicações , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Armadilhas Extracelulares/metabolismo , Humanos , Rim/patologia , Pulmão/patologia , Neutrófilos/citologia , Neutrófilos/metabolismo , Neutrófilos/patologia , Pandemias , Fenótipo , Ativação Plaquetária , Pneumonia Viral/complicações , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Insuficiência Respiratória/diagnóstico , Índice de Gravidade de Doença , Trombose/complicações , Trombose/diagnóstico
9.
Geriatr Gerontol Int ; 20(10): 932-937, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32857477

RESUMO

OBJECTIVES: Percutaneous endoscopic gastrostomy (PEG) is one of the methods of tube feeding in patients who are incapable of oral intake. There are no reports on risk factors for bleeding at PEG construction. Our main objective was to investigate the risks and predictors of bleeding associated with PEG construction. METHODS: This retrospective, observational study included patients who had undergone PEG construction at our institution. To investigate the risks of bleeding associated with PEG construction, we compared the baseline characteristics between bleeding and non-bleeding patients. In terms of early predictors of post-PEG bleeding, we evaluated whether there had been a decrease from baseline of >10% in hemoglobin levels on the day after the procedure. RESULTS: The median preoperative albumin levels were 22.5 g/L (range 20-29 g/L) and 30 g/L (range 18-40 g/L) in the bleeding and non-bleeding groups, respectively (P = 0.014, Mann-Whitney U-test). The median preoperative platelet counts were 177 500 (range 87 000-265 000) and 271 000 (83 000-749 000) in the bleeding and non-bleeding groups, respectively (P = 0.043, Mann-Whitney U-test). The number of patients for whom hemoglobin levels decreased >10% from baseline on the day after the procedure differed significantly between the bleeding and non-bleeding groups (2/4, 50% and 3/58, 5.45%), respectively (P = 0.002, Pearson's χ2 -test). CONCLUSIONS: Low serum albumin and preoperative platelet counts might be risk factors for bleeding. Rigorous follow up is necessary for patients showing a decrease in hemoglobin level ≥10% of their baseline the day after the procedure. Geriatr Gerontol Int 2020; 20: 932-937.


Assuntos
Perda Sanguínea Cirúrgica/estatística & dados numéricos , Nutrição Enteral , Gastrostomia/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Plaquetas/metabolismo , Feminino , Gastroscopia , Hemoglobinas/metabolismo , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Albumina Sérica Humana/metabolismo , Adulto Jovem
10.
Blood Adv ; 4(13): 2967-2978, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32609845

RESUMO

Thrombocytopenia is a common complication of influenza virus infection, and its severity predicts the clinical outcome of critically ill patients. The underlying cause(s) remain incompletely understood. In this study, in patients with an influenza A/H1N1 virus infection, viral load and platelet count correlated inversely during the acute infection phase. We confirmed this finding in a ferret model of influenza virus infection. In these animals, platelet count decreased with the degree of virus pathogenicity varying from 0% in animals infected with the influenza A/H3N2 virus, to 22% in those with the pandemic influenza A/H1N1 virus, up to 62% in animals with a highly pathogenic A/H5N1 virus infection. This thrombocytopenia is associated with virus-containing platelets that circulate in the blood. Uptake of influenza virus particles by platelets requires binding to sialoglycans and results in the removal of sialic acids by the virus neuraminidase, a trigger for hepatic clearance of platelets. We propose the clearance of influenza virus by platelets as a paradigm. These insights clarify the pathophysiology of influenza virus infection and show how severe respiratory infections, including COVID-19, may propagate thrombocytopenia and/or thromboembolic complications.


Assuntos
Plaquetas/virologia , Vírus da Influenza A/patogenicidade , Influenza Humana/complicações , Ácido N-Acetilneuramínico/metabolismo , Polissacarídeos/metabolismo , Trombocitopenia/etiologia , Animais , Plaquetas/metabolismo , Plaquetas/patologia , Modelos Animais de Doenças , Furões , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A Subtipo H3N2/patogenicidade , Vírus da Influenza A Subtipo H3N2/fisiologia , Virus da Influenza A Subtipo H5N1/patogenicidade , Virus da Influenza A Subtipo H5N1/fisiologia , Vírus da Influenza A/fisiologia , Influenza Humana/metabolismo , Influenza Humana/patologia , Influenza Humana/virologia , Infecções por Orthomyxoviridae/complicações , Infecções por Orthomyxoviridae/metabolismo , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Trombocitopenia/metabolismo , Trombocitopenia/patologia , Trombocitopenia/virologia , Internalização do Vírus
11.
PLoS Negl Trop Dis ; 14(7): e0007656, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32687542

RESUMO

Platelets drive endothelial cell activation in many diseases. However, if this occurs in Plasmodium vivax malaria is unclear. As platelets have been reported to be activated and to play a role in inflammatory response during malaria, we hypothesized that this would correlate with endothelial alterations during acute illness. We performed platelet flow cytometry of PAC-1 and P-selectin. We measured platelet markers (CXCL4, CD40L, P-selectin, Thrombopoietin, IL-11) and endothelial activation markers (ICAM-1, von Willebrand Factor and E-selectin) in plasma with a multiplex-based assay. The values of each mediator were used to generate heatmaps, K-means clustering and Principal Component analysis. In addition, we determined pair-wise Pearson's correlation coefficients to generate correlation networks. Platelet counts were reduced, and mean platelet volume increased in malaria patients. The activation of circulating platelets in flow cytometry did not differ between patients and controls. CD40L levels (Median [IQ]: 517 [406-651] vs. 1029 [732-1267] pg/mL, P = 0.0001) were significantly higher in patients, while P-selectin and CXCL4 showed a nonsignificant trend towards higher levels in patients. The network correlation approach demonstrated the correlation between markers of platelet and endothelial activation, and the heatmaps revealed a distinct pattern of activation in two subsets of P. vivax patients when compared to controls. Although absolute platelet activation was not strong in uncomplicated vivax malaria, markers of platelet activity and production were correlated with higher endothelial cell activation, especially in a specific subset of patients.


Assuntos
Plaquetas/citologia , Malária Vivax/sangue , Adulto , Plaquetas/metabolismo , Ligante de CD40/genética , Ligante de CD40/metabolismo , Selectina E/genética , Selectina E/metabolismo , Células Endoteliais/metabolismo , Feminino , Humanos , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Interleucina-11/genética , Interleucina-11/metabolismo , Malária Vivax/genética , Malária Vivax/metabolismo , Masculino , Selectina-P/genética , Selectina-P/metabolismo , Ativação Plaquetária , Contagem de Plaquetas , Adulto Jovem
12.
Int J Mol Sci ; 21(14)2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32708334

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), also known as coronavirus disease 2019 (COVID-19)-induced infection, is strongly associated with various coagulopathies that may result in either bleeding and thrombocytopenia or hypercoagulation and thrombosis. Thrombotic and bleeding or thrombotic pathologies are significant accompaniments to acute respiratory syndrome and lung complications in COVID-19. Thrombotic events and bleeding often occur in subjects with weak constitutions, multiple risk factors and comorbidities. Of particular interest are the various circulating inflammatory coagulation biomarkers involved directly in clotting, with specific focus on fibrin(ogen), D-dimer, P-selectin and von Willebrand Factor (VWF). Central to the activity of these biomarkers are their receptors and signalling pathways on endothelial cells, platelets and erythrocytes. In this review, we discuss vascular implications of COVID-19 and relate this to circulating biomarker, endothelial, erythrocyte and platelet dysfunction. During the progression of the disease, these markers may either be within healthy levels, upregulated or eventually depleted. Most significant is that patients need to be treated early in the disease progression, when high levels of VWF, P-selectin and fibrinogen are present, with normal or slightly increased levels of D-dimer (however, D-dimer levels will rapidly increase as the disease progresses). Progression to VWF and fibrinogen depletion with high D-dimer levels and even higher P-selectin levels, followed by the cytokine storm, will be indicative of a poor prognosis. We conclude by looking at point-of-care devices and methodologies in COVID-19 management and suggest that a personalized medicine approach should be considered in the treatment of patients.


Assuntos
Plaquetas/metabolismo , Infecções por Coronavirus/patologia , Células Endoteliais/metabolismo , Eritrócitos/metabolismo , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Selectina-P/metabolismo , Pneumonia Viral/patologia , Fator de von Willebrand/metabolismo , Betacoronavirus , Síndrome da Liberação de Citocina/patologia , Humanos , Pandemias , Sistemas Automatizados de Assistência Junto ao Leito , Medicina de Precisão/métodos , Trombocitopenia/patologia , Trombose/patologia
13.
Medicine (Baltimore) ; 99(27): e20888, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32629679

RESUMO

This study aims to identify prognostic value of neutrophil-to-lymphocyte ratio (NLR) in early miscarriages. A total of 260 pregnant women with vaginal spotting were recruited from the Department of Obstetrics and Gynecology of the Kyung Hee Medical Center from January 1, 2011, and December 31, 2018. Venous samples were obtained from the women for measurements of platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and NLR. All the patients were in < 14 gestational weeks of their pregnancy. Eighty-four patients were excluded because of incomplete data, loss of follow-up, and serious medical diseases. We enrolled 176 women for analysis and divided them into two groups. Group 1 included 104 women with threatened abortion; and group 2, 72 women with missed abortion. A significant difference in NLR was found between the groups (p = 0.001; P < .01). The multivariate analysis also revealed that NLR was the only prognostic factor of early miscarriage (odd ratio [OR], 0.732; 95% confidence interval [CI], 0.612-0.881, P = .001). The area under the Receiver-operating characteristic of NLR for distinguishing between the missed and threatened abortion groups was 0.792, and the best cutoff value was 5.72 (P < .05).


Assuntos
Aborto Espontâneo/sangue , Linfócitos/metabolismo , Neutrófilos/metabolismo , Adulto , Plaquetas/metabolismo , Feminino , Humanos , Monócitos/metabolismo , Gravidez , Prognóstico , Estudos Retrospectivos
14.
Nat Commun ; 11(1): 3569, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678083

RESUMO

The clinically important MAM blood group antigen is present on haematopoietic cells of all humans except rare MAM-negative individuals. Its molecular basis is unknown. By whole-exome sequencing we identify EMP3, encoding epithelial membrane protein 3 (EMP3), as a candidate gene, then demonstrate inactivating mutations in ten known MAM-negative individuals. We show that EMP3, a purported tumour suppressor in various solid tumours, is expressed in erythroid cells. Disruption of EMP3 by CRISPR/Cas9 gene editing in an immortalised human erythroid cell line (BEL-A2) abolishes MAM expression. We find EMP3 to associate with, and stabilise, CD44 in the plasma membrane. Furthermore, cultured erythroid progenitor cells from MAM-negative individuals show markedly increased proliferation and higher reticulocyte yields, suggesting an important regulatory role for EMP3 in erythropoiesis and control of cell production. Our data establish MAM as a new blood group system and demonstrate an interaction of EMP3 with the cell surface signalling molecule CD44.


Assuntos
Antígenos de Grupos Sanguíneos/genética , Proliferação de Células , Células Eritroides/citologia , Glicoproteínas de Membrana/genética , Antígenos de Grupos Sanguíneos/química , Antígenos de Grupos Sanguíneos/metabolismo , Plaquetas/metabolismo , Células Cultivadas , Membrana Eritrocítica/metabolismo , Células Eritroides/metabolismo , Humanos , Receptores de Hialuronatos/metabolismo , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/metabolismo , Modelos Moleculares , Mutação , Fenótipo , Ligação Proteica , Sequenciamento Completo do Exoma
15.
PLoS One ; 15(7): e0235392, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32726315

RESUMO

Platelets upregulate the generation of thrombin and reinforce the fibrin clot which increases the incidence risk of venous thromboembolism (VTE). However, the role of platelets in the pathogenesis of venous cardiovascular diseases remains hard to quantify. An experimentally validated model of thrombin generation dynamics is formulated. The model predicts that a high platelet count increases the peak value of generated thrombin as well as the endogenous thrombin potential (ETP) as reported in experimental data. To investigate the effects of platelets density, shear rate, and wound size on the initiation of blood coagulation, we calibrate a previously developed model of venous thrombus formation and implement it in 3D using a novel cell-centered finite-volume solver. We conduct numerical simulations to reproduce in vitro experiments of blood coagulation in microfluidic capillaries. Then, we derive a reduced one-equation model of thrombin distribution from the previous model under simplifying hypotheses and we use it to determine the conditions of clotting initiation on the platelet count, the shear rate, and the plasma composition. The initiation of clotting also exhibits a threshold response to the size of the wounded region in good agreement with the reported experimental findings.


Assuntos
Coagulação Sanguínea/fisiologia , Plaquetas/fisiologia , Modelos Teóricos , Contagem de Plaquetas/métodos , Testes de Coagulação Sanguínea , Plaquetas/metabolismo , Fibrina/metabolismo , Humanos , Agregação Plaquetária/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Resistência ao Cisalhamento/fisiologia , Trombina/metabolismo , Tromboplastina/metabolismo , Trombose/metabolismo , Trombose/fisiopatologia , Veias/metabolismo , Veias/fisiologia
16.
PLoS Comput Biol ; 16(6): e1007902, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32603371

RESUMO

We present the software platform 2CALM that allows for a comparative analysis of 3D localisation microscopy data representing protein distributions in two biological samples. The in-depth statistical analysis reveals differences between samples at the nanoscopic level using parameters such as cluster-density and -curvature. An automatic classification system combines multiplex and multi-level statistical approaches into one comprehensive parameter for similarity testing of the compared samples. We demonstrated the biological importance of 2CALM, comparing the protein distributions of CD41 and CD62p on activated platelets in a 3D artificial clot. Additionally, using 2CALM, we quantified the impact of the inflammatory cytokine interleukin-1ß on platelet activation in clots. The platform is applicable to any other cell type and biological system and can provide new insights into biological and medical applications.


Assuntos
Plaquetas/metabolismo , Proteínas de Membrana/metabolismo , Microscopia/métodos , Modelos Biológicos , Trombose/metabolismo , Humanos , Aprendizado de Máquina , Selectina-P/metabolismo , Estudo de Prova de Conceito
17.
Food Chem ; 332: 127384, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615384

RESUMO

Dairy polar lipids (PL) seem to exhibit antiplatelet effects. However, it is not known what molecular species may be responsible. In this study, we confirmed using C30 reversed-phase (C30RP) ultra-high-performance liquid chromatography (UHPLC) coupled to high resolution accurate mass tandem mass spectrometry (HRAM-MS/MS) that fermentation of yoghurts from ovine milk using specific starter cultures altered the PL composition. These lipid alterations occurred concomitant with increased antithrombotic properties of the yoghurts PL fractions against platelet-activating factor (PAF) and thrombin-induced platelet aggregation. Specifically, elevation in phosphatidylethanolamine (PE), sphingomyelin (SM), phosphatidylcholine (PC) and their molecular species were observed following yoghurt fermentation. Furthermore, PC(18:0/18:1), PE(18:1/18:2), SM(d18:0/22:0) and several other molecular species were significantly inversely correlated with the inhibition of PAF and thrombin. These molecular species were abundant in the most bioactive yoghurts fermented by S. thermophilus and L. acidophilus, which suggest that fermentation by these microorganisms increases the antithrombotic properties of ovine milk PL.


Assuntos
Lipídeos/análise , Leite/metabolismo , Inibidores da Agregação de Plaquetas/análise , Iogurte/análise , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Cromatografia Líquida de Alta Pressão , Fermentação , Lipídeos/farmacologia , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação de Plaquetas/farmacologia , Ovinos , Esfingomielinas/metabolismo , Espectrometria de Massas em Tandem , Trombina/farmacologia
18.
Blood ; 136(11): 1330-1341, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32678428

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emergent pathogen responsible for the coronavirus disease 2019 (COVID-19). Since its emergence, the novel coronavirus has rapidly achieved pandemic proportions causing remarkably increased morbidity and mortality around the world. A hypercoagulability state has been reported as a major pathologic event in COVID-19, and thromboembolic complications listed among life-threatening complications of the disease. Platelets are chief effector cells of hemostasis and pathological thrombosis. However, the participation of platelets in the pathogenesis of COVID-19 remains elusive. This report demonstrates that increased platelet activation and platelet-monocyte aggregate formation are observed in severe COVID-19 patients, but not in patients presenting mild COVID-19 syndrome. In addition, exposure to plasma from severe COVID-19 patients increased the activation of control platelets ex vivo. In our cohort of COVID-19 patients admitted to the intensive care unit, platelet-monocyte interaction was strongly associated with tissue factor (TF) expression by the monocytes. Platelet activation and monocyte TF expression were associated with markers of coagulation exacerbation as fibrinogen and D-dimers, and were increased in patients requiring invasive mechanical ventilation or patients who evolved with in-hospital mortality. Finally, platelets from severe COVID-19 patients were able to induce TF expression ex vivo in monocytes from healthy volunteers, a phenomenon that was inhibited by platelet P-selectin neutralization or integrin αIIb/ß3 blocking with the aggregation inhibitor abciximab. Altogether, these data shed light on new pathological mechanisms involving platelet activation and platelet-dependent monocyte TF expression, which were associated with COVID-19 severity and mortality.


Assuntos
Betacoronavirus/imunologia , Transtornos da Coagulação Sanguínea/patologia , Plaquetas/patologia , Infecções por Coronavirus/complicações , Monócitos/patologia , Pneumonia Viral/complicações , Tromboplastina/metabolismo , Adulto , Biomarcadores/metabolismo , Transtornos da Coagulação Sanguínea/imunologia , Transtornos da Coagulação Sanguínea/metabolismo , Transtornos da Coagulação Sanguínea/virologia , Plaquetas/metabolismo , Plaquetas/virologia , Estudos de Casos e Controles , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo , Monócitos/virologia , Selectina-P/metabolismo , Pandemias , Ativação Plaquetária , Pneumonia Viral/imunologia , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida
20.
Arterioscler Thromb Vasc Biol ; 40(9): 2114-2126, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32640902

RESUMO

OBJECTIVE: Quantitative relationships between the extent of injury and thrombus formation in vivo are not well understood. Moreover, it has not been investigated how increased injury severity translates to blood-flow modulation. Here, we investigated interconnections between injury length, clot growth, and blood flow in a mouse model of laser-induced thrombosis. Approach and Results: Using intravital microscopy, we analyzed 59 clotting events collected from the cremaster arteriole of 14 adult mice. We regarded injury length as a measure of injury severity. The injury caused transient constriction upstream and downstream of the injury site resulting in a 50% reduction in arteriole diameter. The amount of platelet accumulation and fibrin formation did not depend on arteriole diameter or deformation but displayed an exponentially increasing dependence on injury length. The height of the platelet clot depended linearly on injury length and the arteriole diameter. Upstream arteriolar constriction correlated with delayed upstream velocity increase, which, in turn, determined downstream velocity. Before clot formation, flow velocity positively correlated with the arteriole diameter. After the onset of thrombus growth, flow velocity at the injury site negatively correlated with the arteriole diameter and with the size of the above-clot lumen. CONCLUSIONS: Injury severity increased platelet accumulation and fibrin formation in a persistently steep fashion and, together with arteriole diameter, defined clot height. Arterial constriction and clot formation were characterized by a dynamic change in the blood flow, associated with increased flow velocity.


Assuntos
Músculos Abdominais/irrigação sanguínea , Arteríolas/patologia , Coagulação Sanguínea , Trombose/patologia , Lesões do Sistema Vascular/patologia , Animais , Arteríolas/lesões , Arteríolas/fisiopatologia , Velocidade do Fluxo Sanguíneo , Plaquetas/metabolismo , Constrição Patológica , Modelos Animais de Doenças , Fibrina/metabolismo , Microscopia Intravital , Masculino , Camundongos , Microscopia de Fluorescência , Índice de Gravidade de Doença , Trombose/sangue , Trombose/fisiopatologia , Fatores de Tempo , Lesões do Sistema Vascular/sangue , Lesões do Sistema Vascular/fisiopatologia
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