| 1. |
- Malmström, Erik, et al.
(författare)
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Targeted mass spectrometry analysis of neutrophil-derived proteins released during sepsis progression.
- 2014
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Ingår i: Thrombosis and Haemostasis. - 0340-6245. ; 112:6, s. 1230-1243
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Tidskriftsartikel (refereegranskat)abstract
- Early diagnosis of severe infectious diseases is essential for timely implementation of lifesaving therapies. In a search for novel biomarkers in sepsis diagnosis we focused on polymorphonuclear neutrophils (PMNs). Notably, PMNs have their protein cargo readily stored in granules and following systemic stimulation an immediate increase of neutrophil-borne proteins can be observed into the circulation of sepsis patients. We applied a combination of mass spectrometry (MS) based approaches, LC-MS/MS and selected reaction monitoring (SRM), to characterise and quantify the neutrophil proteome in healthy or disease conditions. With this approach we identified a neutrophil-derived protein abundance pattern in blood plasma consisting of 20 proteins that can be used as a protein signature for severe infectious diseases. Our results also show that SRM is highly sensitive, specific, and reproducible and, thus, a promising technology to study a complex, dynamic and multifactorial disease such as sepsis.
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| 2. |
- Naudin, Clément, et al.
(författare)
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Active but inoperable thrombin is accumulated in a plasma protein layer surrounding Streptococcus pyogenes.
- 2015
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Ingår i: Thrombosis and Haemostasis. - 0340-6245. ; 114:4, s. 717-726
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Tidskriftsartikel (refereegranskat)abstract
- Activation of thrombin is a critical determinant in many physiological and pathological processes including haemostasis and inflammation. Under physiological conditions many of these functions are involved in wound healing or eradication of an invading pathogen. However, when activated systemically, thrombin can contribute to severe and life-threatening conditions by causing complications such as multiple multi-organ failure and disseminated intravascular coagulation. In the present study we investigated how the activity of thrombin is modulated when it is bound to the surface of Streptococcus pyogenes. Our data show that S. pyogenes bacteria become covered with a proteinaceous layer when incubated with human plasma, and that thrombin is a constituent of this layer. Though the coagulation factor is found attached to the bacteria with a functional active site, thrombin has lost its capacity to interact with its natural substrates and inhibitors. Thus, the interaction of bacteria with human plasma renders thrombin completely inoperable at the streptococcal surface. This could represent a host defense mechanism to avoid systemic activation of coagulation which could be otherwise induced when bacteria enter the circulation and cause systemic infection.
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| 3. |
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| 4. |
- Påhlman, Lars, et al.
(författare)
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Antimicrobial activity of fibrinogen and fibrinogen-derived peptides : a novel link between coagulation and innate immunity
- 2013
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Ingår i: Thrombosis and Haemostasis. - 0340-6245 .- 2567-689X. ; 109:5, s. 930-939
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Tidskriftsartikel (refereegranskat)abstract
- Fibrinogen is a key player in the blood coagulation system, and is upon activation with thrombin converted into fibrin that subsequently forms a fibrin clot. In the present study, we investigated the role of fibrinogen in the early innate immune response. Here we show that the viability of fibrinogen-binding bacteria is affected in human plasma activated with thrombin. Moreover, we found that the peptide fragment GHR28 released from the β-chain of fibrinogen has antimicrobial activity against bacteria that bind fibrinogen to their surface, whereas non-binding strains are unaffected. Notably, bacterial killing was detected in Group A Streptococcus bacteria entrapped in a fibrin clot, suggesting that fibrinogen and coagulation is involved in the early innate immune system to quickly wall off and neutralise invading pathogens.
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| 5. |
- Verkleij, Chantal J. N., et al.
(författare)
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The effects of hyperglycaemia on thrombin-activatable fibrinolysis inhibitor
- 2009
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Ingår i: Thrombosis and Haemostasis. - 0340-6245. ; 102:3, s. 460-468
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Tidskriftsartikel (refereegranskat)abstract
- Epidemiological studies have shown a strong association between type 2 diabetes mellitus and cardiovascular diseases, and hypofibrinolysis may contribute to this phenomenon. The aim of this study was to determine the effect of hyperglycaemia on thrombin-activatable fibrinolysis inhibitor (TAR). Hyperglycaemia was mimicked in vitro by incubation of TAFI with glyceraldehyde and in vivo by hyperglycaemic clamping of healthy volunteers. The effects of long-term hyperglycaemia in vivo on TAR were investigated by comparing TAFI from poorly regulated and tightly regulated patients with type 2 diabetes. In vitro glycated TAR showed an altered migration pattern on SDS-PAGE due to aggregation. Glycated TAFI showed decreased activity after activation by thrombin-thrombomodulin in a glyceraldehyde-dose-dependent manner and a reduced anti-fibrinolytic potential. In vivo, no differences in TAR parameters were found after hyperglycaemic clamping of healthy volunteers and between tightly and poorly regulated patients with type 2 diabetes. Moreover, TAR purified from poorly regulated and tightly regulated patients with type 2 diabetes migrated similarly on SDS-PAGE, indicating little or no glycation of the protein. Despite the deleterious effects of glycation of TAR in vitro on its function,TAFI was neither affected by hyperglycaemic clamping, nor by long-term hyperglycaemia in patients with type 2 diabetes. This is in contrast to fibrinolytic factors as plasminogen-activator inhibitor I and tissue-type plasminogen activator, which are affected. We therefore hypothesise that a normally functioning TAR under hyperglycaemic conditions may tip the haemostatic balance towards hypofibrinolysis, which may contribute to the development of cardiovascular diseases in type 2 diabetic patients.
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