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- Bergemalm, Daniel, 1977-, et al.
(författare)
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Platelet proteome and function in X-linked thrombocytopenia with thalassemia and in silico comparisons with gray platelet syndrome
- 2021
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 106:11
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Tidskriftsartikel (refereegranskat)abstract
- In X-linked thrombocytopenia with thalassemia (XLTT; OMIM 314050), caused by the mutation p.R216Q in exon 4 of the GATA1 gene, male hemizygous patients display macrothrombocytopenia, bleeding diathesis and a β-thalassemia trait. Herein, we describe findings in two unrelated Swedish XLTT families with a bleeding tendency exceeding what is expected from the thrombocytopenia. Blood tests revealed low P-PAI-1 and P-factor 5, and elevated S-thrombopoietin levels. Transmission electron microscopy showed diminished numbers of platelet α- and dense granules. The proteomes of isolated blood platelets from 5 male XLTT patients, compared to 5 gender- and age matched controls, were explored. Quantitative mass spectrometry showed alterations of 83 proteins (fold change ≥±1.2, q< .05). Of 46 downregulated proteins, 39 were previously reported to be associated with platelet granules. Reduced protein levels of PTGS1 and SLC35D3 were validated in megakaryocytes of XLTT bone marrow biopsies by immunohistochemistry. Platelet function testing by flow cytometry revealed low dense- and α-granule release and fibrinogen binding in response to ligation of receptors for ADP, the thrombin receptor PAR4 and the collagen receptor GPVI. Significant reductions of a number of α-granule proteins overlapped with a previous platelet proteomics investigation in the inherited macrothrombocytopenia gray platelet syndrome (GPS). In contrast, Ca2+ transporter proteins that facilitate dense granule release were downregulated in XLTT but upregulated in GPS. Ingenuity Pathway Analysis showed altered Coagulation System and Protein Ubiquitination pathways in the XLTT platelets. Collectively, the results revealed protein and functional alterations affecting platelet α- and dense granules in XLTT, probably contributing to bleeding.
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| 2. |
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| 3. |
- Törnudd, Mattias, et al.
(författare)
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Quantification of platelet function : a comparative study of venous and arterial blood using a novel flow cytometry protocol
- 2022
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Ingår i: Platelets. - Abingdon, United Kingdom : Taylor & Francis. - 0953-7104 .- 1369-1635. ; 33:6, s. 926-934
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Tidskriftsartikel (refereegranskat)abstract
- Studies of platelet function in surgical patients often involve both arterial and venous sampling. Possible effects of different sampling sites could be important, but have not been thoroughly investigated. We aimed to compare platelet function in arterial and venous blood samples using a novel flow cytometry protocol and impedance aggregometry. Arterial and venous blood was collected before anesthesia in 10 patients undergoing cardiac surgery of which nine was treated with acetylsalicylic acid until the day before surgery. Flow cytometry included simultaneous analysis of phosphatidylserine exposure, active conformation of the fibrinogen receptor (PAC-1 binding), alpha-granule and lysosomal release (P-selectin and LAMP-1 exposure) and mitochondrial membrane integrity. Platelets were activated with ADP or peptides activating thrombin receptors (PAR1-AP/PAR4-AP) or collagen receptor GPVI (CRP-XL). Leukocyte-platelet conjugates and P-selectin exposure were evaluated immediately in fixated samples. For impedance aggregometry (Multiplate (R)), ADP, arachidonic acid, collagen and PAR1-AP (TRAP) were used as activators. Using impedance aggregometry and in 27 out of 37 parameters studied with flow cytometry there was no significant difference between venous and arterial blood sampling. Arterial blood showed more PAC-1 positive platelets when activated with PAR1-AP or PAR4-AP and venous blood showed more monocyte-platelet and neutrophil-platelet conjugates and higher phosphatidylserine exposure with CRP-XL alone and combined with PAR1-AP or PAR4-AP. We found no differences using impedance aggregometry. In conclusion, testing of platelet function by flow cytometry and impedance aggregometry gave comparable results for most of the studied parameters in venous and arterial samples. Flow cytometry identified differences in PAC-1 binding when activated with PAR1-AP, exposure of phosphatidyl serine and monocyte/neutrophil-platelet conjugates, which might reflect differences in blood sampling technique or in flow conditions in this patient cohort with coronary artery disease. These differences might be considered when comparing data from different sample sites, but caution should be exercised if a different protocol is used or another patient group is studied.
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| 4. |
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| 5. |
- Basabe-Desmonts, L., et al.
(författare)
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Disposable bioanalytical microdevice for monitoring the effect of anti-platelet drugs
- 2010
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Ingår i: 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010. - : CBMS. - 9781618390622 ; , s. 1388-1390
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Konferensbidrag (refereegranskat)abstract
- We report a disposable self-powered integrated microfluidic chip that enables a rapid and simple platelet-function assay from small samples of whole blood. The chip integrates a single-cell adhesion assay with a microfluidic platform; it enables accurate quantification of platelet adhesion, and it controls whole blood flow rate, shear stress, volume of sample, and assay time.
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| 6. |
- Basabe-Desmonts, L., et al.
(författare)
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Single-Step Separation of Platelets from Whole Blood Coupled with Digital Quantification by Interfacial Platelet Cytometry (iPC)
- 2010
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 26:18, s. 14700-14706
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Tidskriftsartikel (refereegranskat)abstract
- We report the efficient single-step separation of individual platelets from unprocessed whole blood, enabling digital quantification of platelet function using interfacial platelet cytometry (iPC) on a chip iPC is accomplished by the precision micropatterning of platelet-specific protein surfaces on solid substrates By separating platelets From whole blood using specific binding to protein spots of a defined size. iPC implements a simple incubate-and-rinse approach, without sample preparation, that enables (I) the study of platelets in the physiological situation of interaction with a protein surface, (2) the choice of the number of platelets bound on each protein spot, from one to many, (3) control of the platelet platelet distance, including the possibility to study noninteracting single platelets, (4) digital quantification (counting) of platelet adhesion to selected protein matrices, enabling statistical characterization of platelet subpopuladons from meaningfully large numbers of single platelets, (5) the study of platelet receptor expression and spatial distribution, and (6) a detailed study of the morphology of isolated single platelets at activation levels that can be manipulated To date, we have demonstrated 1-4 of the above list Platelets were separated from whole blood using tPC with fibrinogen, von Willebrand factor (VWF), and anti-CD42b antibody printed "spots" ranging from a fraction of one to several platelet diameters (2-24 full) The number of platelets captured per spot depends strongly on the protein matrix and the surface area of the spot, together with the platelet volume, morphology, and activation state Blood samples from healthy donors, a May-Hegglin-anomaly patient, and a Glanzmann's Thrombasthenia patient were analyzed via iPC to confirm the specificity of the interaction between protein matrices and platelets For example, the results indicate that platelets interact with fibrinogen spots only through the fibrinogen receptor (aIlb beta 3) and, relevant to diagnostic applications, platelet adhesion correlates strongly with normal versus abnormal platelet function A critical function of platelets is to adhere to regions of damage on blood vessel walls, in contrast to conventional flow cytometry, where platelets are suspended in solution, iPC enables physiologically relevant platelet bioassays based on platelet/protein-matrix inter actions on surfaces. This technology should be inexpensive to implement in clinical assay format, is readily integrable into fluidic microdevices, and paves the way for high-throughput platelet assays from microliter volumes of whole blood.
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| 9. |
- Befekadu, Rahel, 1968-, et al.
(författare)
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Dynamic Changes in Pentraxin-3 and Neprilysin in ST Segment Elevation Myocardial Infarction
- 2022
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Ingår i: Biomedicines. - : MDPI. - 2227-9059. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- Pentraxin-3 (PTX3) and neprilysin have been associated with increased morbidity and mortality in chronic inflammatory disease and heart failure, but these biomarkers have been studied less in patients with ST segment elevation myocardial infarction (STEMI). We investigated the dynamic changes in these biomarkers, as well as the well-known C-reactive protein (CRP), in STEMI patients. PTX3, neprilysin and CRP were measured in samples from 165 STEMI patients, collected at the acute stage, 1-3 days after and 3 months after percutaneous coronary intervention (PCI), and from 40 healthy donors. Patient survival was followed for approximately 8 years after the PCI. As compared with samples from healthy donors, plasma levels of CRP and PTX3 were significantly increased in the acute samples and 1-3 days after PCI, but not at 3 months. CRP levels peaked at 1-3 days, while PTX3 was similarly high in both acute and 1-3 days samples. For neprilysin, no significant differences were observed at the group level. We found no significant differences when comparing patients with patent versus occluded culprit vessels or between patients having a thrombus aspiration or not. However, we found a significant reduction in survival for individuals with PTX3 above the median, both for samples collected at the acute stage and 1-3 days after PCI (p = 0.0001 and p = 0.0008, respectively). For CRP, no significant differences were observed using this approach, but patients above the reference range for healthy donors in the acute samples showed significantly lower survival (p = 0.0476). Conclusions: Survival analysis suggests that PTX3 might be a promising marker to predict mortality in this patient population.
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| 10. |
- Befekadu, Rahel, 1968-, et al.
(författare)
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Levels of soluble tumor necrosis factor receptor 1 and 2 are associated with survival after ST segment elevation myocardial infarction
- 2022
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- The soluble tumor necrosis factor receptors (sTNFR1 and sTNFR2) are suggested to play dual roles on physiological and pathophysiological actions of TNF-α. The aim of this study was to investigate the dynamic changes of these biomarkers in patients with ST-segment elevation myocardial infarction (STEMI). Blood was collected from 165 STEMI patients at admission, 1-3 days and 3 months after percutaneous coronary intervention (PCI) and from 40 healthy blood donors. sTNFR1 and sTNFR2 were measured with ELISA. The plasma levels of both sTNFR1 and sTNFR2 were significantly higher than in healthy donors at all three time points. We found no significant differences in sTNFR1 or sTNFR2 when comparing patients with patent versus occluded culprit vessels, or between patients having a thrombus aspiration or not. Survival analysis was performed comparing patients with levels of biomarkers above and below the median values at that time point. We found significant differences in survival for sTNFR2 in acute samples (p = 0.0151) and for both sTNFR1 and sTNFR2 in samples 1-3 days after PCI (p = 0.0054 and p = 0.0003, respectively). Survival analyses suggest that sTNFR1 or sTNFR2 could be promising markers to predict mortality in STEMI patients after PCI.
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