Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 501
Filtrar
1.
Anal Chim Acta ; 1191: 339286, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35033253

RESUMO

Inositol phosphates belong to a family of structurally diverse signaling molecules playing crucial role in Ca2+ release from intracellular storage vesicles. There are many possibilities of phosphorylation, including their degree and position. Inositol (1,4,5) trisphosphate has been well recognized as the most important second messenger among this family. It remains a challenge to analyse the entire inositol phosphate metabolite family due to its structural complexity, high polarity, and high phosphate density. In this study, we have established an improved UHPLC-ESI-MS/MS method based on a differential isotope labelling methylation strategy. An SPE extraction kit composed of TiO2 and PTFE filter was employed for sample preparation which provided good extraction performance. Samples were methylated (light label) to neutralize the phosphate groups and give better performance in liquid chromatography. Regioisomers and inositol phosphates differing in their number of phosphate residues were successfully separated after optimization on a core-shell cholesterylether-bonded RP-type column (Cosmocore 2.6Cholester) using methanol as organic modifier. Triple quadrupole MS detection was based on selected reaction monitoring (SRM) acquisition with characteristic fragments. Stable isotope labeling methylation was performed to generate internal standards (heavy label). Limits of quantification from 0.32 to 0.89 pmol on column was achieved. This method was validated to be suitable for inositol phosphate profiling in biological samples. After application in cultured HeLa cells, NIST SRM1950 plasma, and human platelets, distinct inositol profiles were obtained. This newly established method exhibited improved analytical performance, holding the potential to advance the understanding of inositol phosphate signaling.


Assuntos
Extração em Fase Sólida , Espectrometria de Massas em Tandem , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Células HeLa , Humanos , Fosfatos de Inositol , Marcação por Isótopo , Metilação , Fosfatos
2.
Hamostaseologie ; 2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34879422

RESUMO

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection is associated with high risk of venous and arterial thrombosis. Thrombotic complications, especially pulmonary embolism, lead to increased all-cause mortality in both intensive care unit and noncritically ill patients. Damage and activation of vascular endothelium, platelet activation, followed by thrombotic and fibrinolytic imbalance as well as hypercoagulability are the key pathomechanisms in immunothrombosis leading to a significant increase in thromboembolism in coronavirus disease 2019 (COVID-19) compared with other acute illnesses. In this review article, we discuss the incidence and prognosis, diagnosis, prevention, and treatment of venous thromboembolism in patients with COVID-19 disease, based on clinical experience and research available to date.

3.
Blood ; 2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-34905596

RESUMO

Platelet ACKR3/CXCR7 surface expression is enhanced and influences prognosis in coronary artery disease-(CAD) patients, who exhibit a distinct atherothrombotic platelet lipidome. Current investigation validates the potential of ACKR3/CXCR7 in regulating thrombo-inflammatory response, through its impact on the platelet lipidome. CAD patients-(n=230) with enhanced platelet-ACKR3/CXCR7 expression exhibited reduced aggregation. Pharmacological CXCR7-agonist-(VUF11207) significantly reduced pro-thrombotic platelet response in blood from ACS patients-(n=11) ex vivo. CXCR7-agonist administration reduced thrombotic functions and thrombo-inflammatory platelet-leukocyte interactions post myocardial infarction-(MI) and arterial injury in vivo. ACKR3/CXCR7-ligation did not affect surface availability of GPIbα, GPV, GPVI, GPIX, αv-integrin, ß3-integrin, coagulation profile-(APTT, PT), bleeding time, plasma-dependent thrombin generation-(thrombinoscopy) or clot formation-(thromboelastography), but counteracted activation-induced phosphatidylserine exposure and procoagulant platelet-assisted thrombin generation. Targeted-(micro-UHPLC-ESI-QTrap-MS/MS) and untargeted-(UHPLC-ESI-QTOF-MS/MS) lipidomics analysis revealed that ACKR3/CXCR7-ligation favored generation of anti-thrombotic lipids-(dihomo-γ-linolenic acid-DGLA, 12-hydroxyeicosatrienoic acid-12-HETrE) over cyclooxygenase-COX-1-(thromboxane-TxA2), or 12-lipoxygenase-LOX-(12-HETE) metabolized pro-thrombotic, and phospholipase derived atherogenic-(lysophosphatidylcholine-LPC) lipids, in healthy subjects and CAD patients, contrary to anti-platelet therapy. Through 12-HETrE, ACKR3/CXCR7-ligation coordinated with Gαs-coupled prostacyclin receptor-(IP) to trigger cAMP-PKA mediated platelet inhibition. ACKR3/CXCR7-ligation reduced generation of lipid agonists-(arachidonic acid-AA,TxA2), lipid signaling intermediates-(lyophosphatidylinositol-LPI, diacylglycerol-DG), which affected calcium mobilization, intracellular signaling, consequently platelet interaction with physiological matrices and thrombo-inflammatory secretion-(IL1ß,IFN-γ,TGF-ß,IL-8), emphasizing its functional dichotomy from pro-thrombotic CXCR4. Moreover, CXCR7-agonist regulated heparin-induced thrombocytopenia-(HIT)-sera/IgG-induced platelet and neutrophil activation, heparin induced platelet aggregation-(HIPA), generation of COX-1-(TxA2), 12-LOX-(12-HETE) derived thrombo-inflammatory lipids, platelet-neutrophil aggregate formation, and thrombo-inflammatory secretion (sCD40L, IL-1ß, IFN-γ, TNF-α, sP-selectin, IL-8, tissue factor-TF) ex vivo. Therefore, ACKR3/CXCR7 may offer a novel therapeutic strategy in acute/chronic thrombo-inflammation exaggerated cardiovascular pathologies, and CAD.

4.
Blood Adv ; 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34753174

RESUMO

Thromboembolic events are frequently reported in patients infected with the SARS-CoV-2 virus. The exact mechanisms of COVID-19 associated hypercoagulopathy, however, remain elusive. Recently, we observed that platelets (PLTs) from patients with severe COVID-19 infection express high levels of procoagulant markers, which were found to be associated with increased risk for thrombosis. In the current study, we investigated the time course as well as the mechanisms leading to procoagulant PLTs in COVID-19. Our study demonstrates the presence of PLT-reactive IgG antibodies that induce marked changes in PLTs in terms of increased inner-mitochondrial-transmembrane potential (Δψ) depolarization, phosphatidylserine (PS) externalization and P-selectin expression. The IgG-induced procoagulant PLTs and increased thrombus formation was mediated by ligation of PLT Fc gamma RIIA (FcγRIIA). In addition, PLTs´ contents of calcium and cyclic-adenosine-monophosphate (cAMP) were identified to play central role in antibody-induced procoagulant PLT formation. Most importantly, antibody-induced procoagulant events as well as increased thrombus formation in severe COVID-19 were inhibited by Iloprost a clinically approved therapeutic agent that increases the intracellular cAMP levels in PLTs. Our data indicate that upregulation of cAMP could be a potential therapeutic target to prevent antibody-mediated coagulopathy in COVID-19 disease.

5.
Cells ; 10(11)2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34831155

RESUMO

Platelets are functionally versatile blood cells involved in thrombosis, hemostasis, atherosclerosis, and immune response. Platelet interaction with the immediate microenvironment in blood, vasculature, and tissues alters platelet morphology. The quantification of platelet morphodynamics by geometrical parameters (morphometry) can provide important insights into how platelets sense and respond to stimulatory cues in their vicinity. However, the extraction of platelet shapes from phase contrast microscopy images by conventional image processing is difficult. Here, we used a convolutional neural network (CNN) to develop a deep-learning-based approach for the unbiased extraction of information on platelet morphodynamics by phase contrast microscopy. We then investigated the effect of normal and oxidized low-density lipoproteins (LDL, oxLDL) on platelet morphodynamics, spreading, and haptotactic migration. Exposure of platelets to oxLDL led to a decreased spreading area and rate on fibrinogen, accompanied by increased formation of filopodia and impaired formation of lamellipodia. Haptotactic platelet migration was affected by both LDL and oxLDL in terms of decreased migration velocity and reduced directional persistence. Our results demonstrate the use of deep learning in investigating platelet morphodynamics and reveal differential effects of LDL and oxLDL on platelet morphology and platelet-matrix interaction.

6.
Hamostaseologie ; 41(5): 347-348, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34695851

RESUMO

The COVID-19 pandemic is still threatening us, our patients, and the global health care system. Since the first outbreak at the end of 2019 in China, it became rapidly clear that a new variant of a SARS virus, SARS-CoV-2, is threatening our human society worldwide. Since then, the scientific community has accumulated an incredibly large amount of knowledge about the pathophysiology of this virus, primarily affecting the respiratory tract and, in severe cases, subsequently resulting in acute respiratory distress syndrome and multiple organ failure due to uncontrolled systemic inflammatory response syndrome.1 2.


Assuntos
COVID-19/fisiopatologia , SARS-CoV-2 , Biomarcadores/metabolismo , Vasos Sanguíneos/fisiopatologia , COVID-19/complicações , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/fisiopatologia , Coração/fisiopatologia , Humanos , Pulmão/fisiopatologia , Pandemias , SARS-CoV-2/patogenicidade
7.
Hamostaseologie ; 41(5): 379-385, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34695854

RESUMO

In 2019 first reports about a new human coronavirus emerged, which causes common cold symptoms as well as acute respiratory distress syndrome. The virus was identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and severe thrombotic events including deep vein thrombosis, pulmonary embolism, and microthrombi emerged as additional symptoms. Heart failure, myocardial infarction, myocarditis, and stroke have also been observed. As main mediator of thrombus formation, platelets became one of the key aspects in SARS-CoV-2 research. Platelets may also directly interact with SARS-CoV-2 and have been shown to carry the SARS-CoV-2 virus. Platelets can also facilitate the virus uptake by secretion of the subtilisin-like proprotein convertase furin. Cleavage of the SARS-CoV-2 spike protein by furin enhances binding capabilities and virus entry into various cell types. In COVID-19 patients, platelet count differs between mild and serious infections. Patients with mild symptoms have a slightly increased platelet count, whereas thrombocytopenia is a hallmark of severe COVID-19 infections. Low platelet count can be attributed to platelet apoptosis and the incorporation of platelets into microthrombi (peripheral consumption) and severe thrombotic events. The observed excessive formation of thrombi is due to hyperactivation of platelets caused by the infection. Various factors have been suggested in the activation of platelets in COVID-19, such as hypoxia, vessel damage, inflammatory factors, NETosis, SARS-CoV-2 interaction, autoimmune reactions, and autocrine activation. COVID-19 does alter chemokine and cytokine plasma concentrations. Platelet chemokine profiles are altered in COVID-19 and contribute to the described chemokine storms observed in severely ill COVID-19 patients.


Assuntos
Plaquetas/fisiologia , Plaquetas/virologia , COVID-19/sangue , Plaquetas/imunologia , COVID-19/complicações , COVID-19/imunologia , Quimiocinas/sangue , Síndrome da Liberação de Citocina/sangue , Síndrome da Liberação de Citocina/etiologia , Interações entre Hospedeiro e Microrganismos/imunologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Humanos , Modelos Biológicos , Pandemias , Ativação Plaquetária/imunologia , Ativação Plaquetária/fisiologia , SARS-CoV-2/patogenicidade , Trombose/sangue , Trombose/etiologia
8.
Artigo em Inglês | MEDLINE | ID: mdl-34656480

RESUMO

OBJECTIVES: The purpose of this study was to investigate the diagnostic value of simultaneous hybrid cardiac magnetic resonance (CMR) and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) for detection and differentiation of active (aCS) from chronic (cCS) cardiac sarcoidosis. BACKGROUND: Late gadolinium enhancement (LGE) CMR and FDG-PET are both established imaging techniques for the detection of CS. However, there are limited data regarding the value of a comprehensive simultaneous hybrid CMR/FDG-PET imaging approach that includes CMR mapping techniques. METHODS: Forty-three patients with biopsy-proven extracardiac sarcoidosis (median age: 48 years, interquartile range: 37-57 years, 65% male) were prospectively enrolled for evaluation of suspected CS. After dietary preparation for suppression of myocardial glucose metabolism, patients were evaluated on a 3-T hybrid PET/MR scanner. The CMR protocol included T1 and T2 mapping, myocardial function, and LGE imaging. We assumed aCS if PET and CMR (ie, LGE or T1/T2 mapping) were both positive (PET+/CMR+), cCS if PET was negative but CMR was positive (PET-/CMR+), and no CS if patients were CMR negative regardless of PET findings. RESULTS: Among the 43 patients, myocardial glucose uptake was suppressed successfully in 36 (84%). Hybrid CMR/FDG-PET revealed aCS in 13 patients (36%), cCS in 5 (14%), and no CS in 18 (50%). LGE was present in 14 patients (39%); T1 mapping was abnormal in 10 (27%) and T2 mapping abnormal in 2 (6%). CS was diagnosed based on abnormal T1 mapping in 4 out of 18 CS patients (22%) who were LGE negative. PET FDG uptake was present in 17 (47%) patients. CONCLUSIONS: Comprehensive simultaneous hybrid CMR/FDG-PET imaging is useful for the detection of CS and provides additional value for identifying active disease. Our results may have implications for enhanced diagnosis as well as improved identification of patients with aCS in whom anti-inflammatory therapy may be most beneficial.

9.
Int J Mol Sci ; 22(20)2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34681838

RESUMO

Platelets play a significant role in atherothrombosis. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is critically involved in the regulation of LDL metabolism and interacts with platelet function. The effect of PCSK9 in platelet function is poorly understood. The authors of this article sought to characterize platelets as a major source of PCSK9 and PCSK9's role in atherothrombosis. In a large cohort of patients with coronary artery disease (CAD), platelet count, platelet reactivity, and platelet-derived PCSK9 release were analyzed. The role of platelet PCSK9 on platelet and monocyte function was investigated in vitro. Platelet count and hyper-reactivity correlated with plasma LDL in CAD. The circulating platelets express on their surface and release substantial amounts of PCSK9. Release of PCSK9 augmented platelet-dependent thrombosis, monocyte migration, and differentiation into macrophages/foam cells. Platelets and PCSK9 accumulated in tissue derived from atherosclerotic carotid arteries in areas of macrophages. PCSK9 inhibition reduced platelet activation and platelet-dependent thrombo-inflammation. The authors identified platelets as a source of PCSK9 in CAD, which may have an impact on LDL metabolism. Furthermore, platelet-derived PCSK9 contributes to atherothrombosis, and inhibition of PCSK9 attenuates thrombo-inflammation, which may contribute to the reported beneficial clinical effects.

10.
Hamostaseologie ; 41(5): 400-402, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34492713

RESUMO

In this case report we present a previously healthy 21-year-old male with extensive thromboembolism in the setting of asymptomatic COVID-19 infection and heterozygous factor V Leiden mutation with no additional thrombophilic risk factors.


Assuntos
COVID-19/complicações , Fator V/genética , SARS-CoV-2 , Tromboembolia/complicações , Tromboembolia/genética , Infecções Assintomáticas , COVID-19/diagnóstico , COVID-19/diagnóstico por imagem , Angiografia por Tomografia Computadorizada , Heterozigoto , Humanos , Masculino , Tromboembolia/terapia , Adulto Jovem
11.
J Pharm Biomed Anal ; 205: 114301, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34391135

RESUMO

Lipids play a major role in platelet signaling and activation. In this study, we analyzed the platelet lipidome in an untargeted manner by reversed-phase UHPLC for lipid species separation coupled to high-resolution QTOF-MS/MS in data-independent acquisition (DIA) mode with sequential window acquisition of all theoretical fragment ion mass spectra (SWATH) for compound detection. Lipid identification and peak picking was supported by the characteristic regular elution pattern of lipids differing in carbon and double bond numbers. It was primarily based on post-acquisition targeted feature extraction from the SWATH data. Multiple extracted ion chromatograms (EICs) from SWATH data of diagnostic ions on MS1 and MS2 level from both positive and negative ion mode allowed to distinguish between poorly resolved isomeric lipids based on their distinct fragment ions, which were used for relative quantification at a molecular lipid species level. It supports assay specificity for relative lipid quantitation via multiple quantifiably ions unlike to data-dependent acquisition methods which rely on precursor ions only. This approach was used to analyze human platelet samples. 457 lipids were annotated. Concentrations of lipids were estimated by stable isotope-labelled lipid class-specific internal standards as surrogate calibrants. Heatmaps of lipid concentrations in dependence on carbon and double bond numbers for the distinct lipid classes revealed a snapshot of the platelet lipidome in the resting state with lipid species distributions within classes supporting some functional interpretations. As expected, activation of the platelets by thrombin has led to significant alterations in the platelet lipidome as proven by univariate (volcano plot) and multivariate (PLS-DA) statistics. Several lipids were significantly up-regulated (lysophosphatidylinositols, oxylipins such as thromboxane B2 (TXB2), hydroxyheptadecatrienoic acid (HHT), hydroxyeicosatetraenoic acid (HETE), hydroxyoctadecadienoic acid (HODE), sphingoid-bases, (very) long chain saturated fatty acids) or down-regulated (lysophosphatidylethanolamines, polyunsaturated fatty acids, phosphatidylinositols). Several of them are well known as biomarkers of platelet activation while others may provide some further insights into pathways of platelet activation and platelet metabolism.


Assuntos
Lipidômica , Espectrometria de Massas em Tandem , Plaquetas , Cromatografia Líquida de Alta Pressão , Humanos , Trombina
12.
Heart Lung ; 50(6): 914-918, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34428736

RESUMO

BACKGROUND: Acute respiratory distress syndrome (ARDS) is considered the main cause of COVID-19 associated morbidity and mortality. Early and reliable risk stratification is of crucial clinical importance in order to identify persons at risk for developing a severe course of disease. Deceleration capacity (DC) of heart rate as a marker of cardiac autonomic function predicts outcome in persons with myocardial infarction and heart failure. We hypothesized that reduced modulation of heart rate may be helpful in identifying persons with COVID-19 at risk for developing ARDS. METHODS: We prospectively enrolled 60 consecutive COVID-19 positive persons presenting at the University Hospital of Tuebingen. Arterial blood gas analysis and 24 h-Holter ECG recordings were performed and analyzed at admission. The primary end point was defined as development of ARDS with regards to the Berlin classification. RESULTS: 61.7% (37 of 60 persons) developed an ARDS. In persons with ARDS DC was significantly reduced when compared to persons with milder course of infection (3.2 ms vs. 6.6 ms, p < 0.001). DC achieved a good discrimination performance (AUC = 0.76) for ARDS in COVID-19 persons. In a multivariate analysis, decreased DC was associated with the development of ARDS. CONCLUSION: Our data suggest a promising role of DC to risk stratification in COVID-19.


Assuntos
COVID-19 , Síndrome do Desconforto Respiratório , Desaceleração , Eletrocardiografia Ambulatorial , Humanos , Síndrome do Desconforto Respiratório/diagnóstico , Síndrome do Desconforto Respiratório/epidemiologia , Síndrome do Desconforto Respiratório/etiologia , SARS-CoV-2
13.
Clin Case Rep ; 9(8): e04543, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34429983

RESUMO

50%-60% of patients with chronic mesenteric ischemia suffer from concomitant cardiovascular disease. We therefore suggest an extensive diagnostic screening to detect coronary artery and peripheral arterial disease in these patients.

14.
Blood ; 138(14): 1269-1277, 2021 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-34280256

RESUMO

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a severe adverse effect of ChAdOx1 nCoV-19 COVID-19 vaccine (Vaxzevria) and Janssen Ad26.COV2.S COVID-19 vaccine, and it is associated with unusual thrombosis. VITT is caused by anti-platelet factor 4 (PF4) antibodies activating platelets through their FcγRIIa receptors. Antibodies that activate platelets through FcγRIIa receptors have also been identified in patients with COVID-19. These findings raise concern that vaccination-induced antibodies against anti-SARS-CoV-2 spike protein cause thrombosis by cross-reacting with PF4. Immunogenic epitopes of PF4 and SARS-CoV-2 spike protein were compared using in silico prediction tools and 3D modeling. The SARS-CoV-2 spike protein and PF4 share at least 1 similar epitope. Reactivity of purified anti-PF4 antibodies from patients with VITT was tested against recombinant SARS-CoV-2 spike protein. However, none of the affinity-purified anti-PF4 antibodies from 14 patients with VITT cross-reacted with SARS-CoV-2 spike protein. Sera from 222 polymerase chain reaction-confirmed patients with COVID-19 from 5 European centers were tested by PF4-heparin enzyme-linked immunosorbent assays and PF4-dependent platelet activation assays. We found anti-PF4 antibodies in sera from 19 (8.6%) of 222 patients with COVID-19. However, only 4 showed weak to moderate platelet activation in the presence of PF4, and none of those patients developed thrombotic complications. Among 10 (4.5%) of 222 patients who had COVID-19 with thrombosis, none showed PF4-dependent platelet-activating antibodies. In conclusion, antibodies against PF4 induced by vaccination do not cross-react with the SARS-CoV-2 spike protein, indicating that the intended vaccine-induced immune response against SARS-CoV-2 spike protein is not the trigger of VITT. PF4-reactive antibodies found in patients with COVID-19 in this study were not associated with thrombotic complications.


Assuntos
Anticorpos/efeitos adversos , Vacinas contra COVID-19/efeitos adversos , Reações Cruzadas/imunologia , Fator Plaquetário 4/imunologia , Púrpura Trombocitopênica Idiopática/etiologia , Púrpura Trombocitopênica Idiopática/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Plaquetas/imunologia , COVID-19/imunologia , Estudos de Coortes , Epitopos/imunologia , Feminino , Heparina/metabolismo , Humanos , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Ligação Proteica , Domínios Proteicos , Púrpura Trombocitopênica Idiopática/sangue , Glicoproteína da Espícula de Coronavírus/química , Adulto Jovem
15.
Cardiovasc Res ; 2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34323932

RESUMO

AIMS: Platelets play a key role in the pathophysiology of coronary artery disease (CAD) and patients with enhanced platelet activation are at increased risk to develop adverse cardiovascular events. Beyond reliable cardiovascular risk factors such as dyslipoproteinaemia, significant changes of platelet lipids occur in patients with CAD. In this study, we investigate the platelet lipidome by untargeted liquid chromatography-mass spectrometry, highlighting significant changes between acute coronary syndrome (ACS) and chronic coronary syndrome (CCS) patients. Additionally, we classify the platelet lipidome, spotlighting specific glycerophospholipids as key players in ACS patients. Furthermore, we examine the impact of significantly altered lipids in ACS on platelet-dependent thrombus formation and aggregation. METHODS AND RESULTS: In this consecutive study, we characterized the platelet lipidome in a CAD cohort (n = 139) and showed significant changes of lipids between patients with ACS and CCS. We found that among 928 lipids, 7 platelet glycerophospholipids were significantly up-regulated in ACS, whereas 25 lipids were down-regulated compared to CCS. The most prominent up-regulated lipid in ACS, PC18:0 (PC 10:0-8:0), promoted platelet activation and ex vivo platelet-dependent thrombus formation. CONCLUSIONS: Our results reveal that the platelet lipidome is altered in ACS and up-regulated lipids embody primarily glycerophospholipids. Alterations of the platelet lipidome, especially of medium chain lipids, may play a role in the pathophysiology of ACS.

16.
Pharmgenomics Pers Med ; 14: 893-903, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34321906

RESUMO

Background: Complement component 5a (C5a) is a highly potent anaphylatoxin with a variety of pro-inflammatory effects. C5a contributes to progression of atherosclerosis and inhibition of the receptor (C5aR) might offer a therapeutic strategy in this regard. Single nucleotide polymorphisms (SNPs) of the C5 gene may modify protein expression levels and therefore function of C5a and C5aR. This study aimed to examine associations between clinically relevant C5a SNPs and the prognosis of patients with symptomatic coronary artery disease (CAD). Furthermore, we sought to investigate the influence of C5 SNPs on C5aR platelet surface expression and circulating C5a levels. Methods: C5 variants (rs25681, rs17611, rs17216529, rs12237774, rs41258306, and rs10985126) were analyzed in a consecutive cohort of 833 patients suffering from symptomatic coronary artery disease (CAD). Circulating C5a levels were determined in 116 patients whereas C5aR platelet surface expression was measured in 473 CAD patients. Endpoints included all-cause mortality, myocardial infarction (MI), and ischemic stroke (IS). Homozygous carriers (HC) of the minor allele (rs10985126) showed significantly higher all-cause mortality than major allele carriers. While we could not find significant associations between rs10985126 allele frequency and C5aR platelet surfazl ce expression, significantly elevated levels of circulating C5a were found in HC of the minor allele of the respective genotype. rs17216529 allele frequency correlated with the composite combined endpoint and bleeding events. However, since the number of HC of the minor allele of this genotype was low, we cannot draw a robust conclusion about the observed associations. Conclusion: In this study, we provide evidence for the prognostic relevance of rs10985126 in CAD patients. C5 rs10985126 may serve as a prognostic biomarker for risk stratification in high-risk CAD patients and consequently promote tailored therapies.

18.
Front Cardiovasc Med ; 8: 584108, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34150860

RESUMO

COVID-19 may lead to severe acute respiratory distress syndrome (ARDS) resulting in increased morbidity and mortality. Heart failure and/or pre-existing cardiovascular disease may correlate with poor outcomes and thus require special attention from treating physicians. The present study sought to investigate a possible impact of impaired myocardial function as well as myocardial distress markers on mortality or ARDS with need for mechanical ventilation in 157 consecutive patients with confirmed SARS-CoV-2 infection. All patients were admitted and treated at the University Hospital of Tübingen, Germany, during the first wave of the pandemic. Electrocardiography, echocardiography, and routine blood sampling were performed at hospital admission. Impaired left-ventricular and right-ventricular function, tricuspid regurgitation > grade 1, and elevated RV-pressure as well as thrombotic and myocardial distress markers (D-dimers, NT-pro-BNP, and troponin-I) were associated with mechanical ventilation and/or all-cause mortality. Impaired cardiac function is more frequent amidst ARDS, leading to subsequent need for mechanical ventilation, and thus denotes a poor outcome in COVID-19. Since a causal treatment for SARS-CoV-2 infection is still lacking, guideline-compliant cardiovascular evaluation and treatment remains the best approach to improve outcomes in COVID-19 patients with cardiovascular comorbidities.

19.
Nat Commun ; 12(1): 3352, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099640

RESUMO

Platelets contribute to the regulation of tissue neovascularization, although the specific factors underlying this function are unknown. Here, we identified the complement anaphylatoxin C5a-mediated activation of C5a receptor 1 (C5aR1) on platelets as a negative regulatory mechanism of vessel formation. We showed that platelets expressing C5aR1 exert an inhibitory effect on endothelial cell functions such as migration and 2D and 3D tube formation. Growth factor- and hypoxia-driven vascularization was markedly increased in C5ar1-/- mice. Platelet-specific deletion of C5aR1 resulted in a proangiogenic phenotype with increased collateralization, capillarization and improved pericyte coverage. Mechanistically, we found that C5a induced preferential release of CXC chemokine ligand 4 (CXCL4, PF4) from platelets as an important antiangiogenic paracrine effector molecule. Interfering with the C5aR1-CXCL4 axis reversed the antiangiogenic effect of platelets both in vitro and in vivo.In conclusion, we identified a mechanism for the control of tissue neovascularization through C5a/C5aR1 axis activation in platelets and subsequent induction of the antiangiogenic factor CXCL4.


Assuntos
Plaquetas/metabolismo , Fator Plaquetário 4/metabolismo , Receptor da Anafilatoxina C5a/genética , Receptor da Anafilatoxina C5a/metabolismo , Indutores da Angiogênese , Animais , Ativação do Complemento , Complemento C5a , Inflamação , Camundongos , Camundongos Knockout , Receptor da Anafilatoxina C5a/deficiência , Receptores CXCR3/genética , Transdução de Sinais
20.
J Proteome Res ; 20(6): 3114-3123, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-33938762

RESUMO

Phosphoinositides are minor components of cell membranes, but play crucial roles in numerous signal transduction pathways. To obtain quantitative measures of phosphoinositides, sensitive, accurate, and comprehensive methods are needed. Here, we present a quantitative targeted ion chromatography-mass spectrometry-based workflow that separates phosphoinositide isomers and increases the quantitative accuracy of measured phosphoinositides. Besides testing different analytical characteristics such as extraction and separation efficiency, the reproducibility of the developed workflow was also investigated. The workflow was verified in resting and stimulated human platelets, fat cells, and rat hippocampal brain tissue, where the LOD and LOQ for phosphoinositides were at 312.5 and 625 fmol, respectively. The robustness of the workflow is shown with different applications that confirms its suitability to analyze multiple less-abundant phosphoinositides.


Assuntos
Fosfatidilinositóis , Animais , Cromatografia Líquida , Espectrometria de Massas , Ratos , Reprodutibilidade dos Testes , Fluxo de Trabalho
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...