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Polish Archives of Internal Medicine Aug 2017INTRODUCTION Inherited deficiencies of natural anticoagulants such as antithrombin (AT; gene: SERPINC1), protein C (PC; PROC), and protein S (PS; PROS1), with the...
INTRODUCTION Inherited deficiencies of natural anticoagulants such as antithrombin (AT; gene: SERPINC1), protein C (PC; PROC), and protein S (PS; PROS1), with the prevalence in the general European population of 0.02% to 0.17%, 0.2% to 0.3%, and 0.5%, respectively, are associated with increased risk of thromboembolic events. Only a few case reports of Polish deficient patients with known causal mutations have been published so far. OBJECTIVES The aim of the study was to characterize the frequency of SERPINC1, PROC, and PROS1 mutations and their thromboembolic manifestations in patients with AT, PC, or PS deficiencies, inhabiting southern Poland. PATIENTS AND METHODS Ninety unrelated patients (mean [SD] age, 40.1 [13.2] years) with AT (n = 35), PC (n = 28), or PS (n = 27) deficiencies, with a history of venous 73 (81%) or arterial 17 (19%) thromboembolism, were screened for mutations using the Sanger sequencing or multiplex ligation‑dependent probe amplification. RESULTS Twenty mutations (29%) described here were new, mostly in the SERPINC1 and PROC genes. Missense mutations accounted for 84% of all mutations in the PROC gene and approximately 50% of those in the SERPINC1 and PROS1 genes. In all 3 genes, the ratio of nonsense and splice-site mutations was 8% to 31% and 8% to 23%, respectively. The mutation detection rate was 90% for AT or PC when anticoagulant activity was below 70%, while for the PROS1 gene, the rate reached 80% at the free PS levels below 40%. CONCLUSIONS To our knowledge, this is the largest cohort of Polish patients deficient in natural anticoagulants and evaluated for the causal genetic background. Several new Polish detrimental mutations were detected, mostly in AT- and PC‑deficient patients.
Topics: Adolescent; Adult; Aged; Antithrombin III; Antithrombin III Deficiency; Blood Protein Disorders; Blood Proteins; DNA Mutational Analysis; Female; Humans; Male; Middle Aged; Mutation; Mutation, Missense; Poland; Protein C; Protein C Deficiency; Protein S; Protein S Deficiency; Young Adult
PubMed: 28607330
DOI: 10.20452/pamw.4045 -
Clinical and Applied... 2020Use of left ventricular assist devices (LVADs) for management of advanced heart failure is becoming increasingly common; however, device associated thrombosis remains an...
Use of left ventricular assist devices (LVADs) for management of advanced heart failure is becoming increasingly common; however, device associated thrombosis remains an important cause of mortality in this patient population. We hypothesize that inflammation in LVAD implanted patients dysregulates the protein C pathway, creating a hypercoagulable state leading to thrombosis. Plasma samples from 22 patients implanted with the Thoratec HeartMate II LVAD were analyzed by commercial ELISAs. Retrospective sample selection included those collected 1-3 months prior to and within 1 month after a thrombotic or bleeding event. Unrelated to warfarin dosing, total protein S and free protein S ( = 0.033) levels were 20% lower in patients with LVAD-thrombosis than in patients with LVAD-bleeding. Levels of protein C, soluble endothelial cell protein C receptor, and soluble thrombomodulin were similar in both groups before and after the event. Compared to normal, C-reactive protein levels were 25-fold elevated in LVAD-thrombosis patients but only 9-fold elevated in LVAD-bleeding patients. This study suggests that protein S, influenced by the inflammatory state, is a gatekeeper for the function of protein C in patients with LVAD-associated thrombosis.
Topics: Female; Heart Failure; Heart-Assist Devices; Humans; Inflammation; Male; Protein C; Thrombosis
PubMed: 32970454
DOI: 10.1177/1076029620959724 -
Journal of Thrombosis and Haemostasis :... May 2020Activated protein C (APC) is an important homeostatic blood coagulation protease that conveys anticoagulant and cytoprotective activities. Proteolytic inactivation of...
BACKGROUND
Activated protein C (APC) is an important homeostatic blood coagulation protease that conveys anticoagulant and cytoprotective activities. Proteolytic inactivation of factors Va and VIIIa facilitated by cofactor protein S is responsible for APC's anticoagulant effects, whereas cytoprotective effects of APC involve primarily the endothelial protein C receptor (EPCR), protease activated receptor (PAR)1 and PAR3.
OBJECTIVE
To date, several binding exosites in the protease domain of APC have been identified that contribute to APC's interaction with its substrates but potential contributions of the C-terminus of the light chain have not been studied in detail.
METHODS
Site-directed Ala-scanning mutagenesis of six positively charged residues within G142-L155 was used to characterize their contributions to APC's anticoagulant and cytoprotective activities.
RESULTS AND CONCLUSIONS
K151 was involved in protein S dependent-anticoagulant activity of APC with some contribution of K150. 3D structural analysis supported that these two residues were exposed in an extended protein S binding site on one face of APC. Both K150 and K151 were important for PAR1 and PAR3 cleavage by APC, suggesting that this region may also mediate interactions with PARs. Accordingly, APC's cytoprotective activity as determined by endothelial barrier protection was impaired by Ala substitutions of these residues. Thus, both K150 and K151 are involved in APC's anticoagulant and cytoprotective activities. The differential contribution of K150 relative to K151 for protein S-dependent anticoagulant activity and PAR cleavage highlights that binding exosites for protein S binding and for PAR cleavage in the C-terminal region of APC's light chain overlap.
Topics: Anticoagulants; Blood Coagulation; Factor Va; Humans; Protein C; Receptor, PAR-1
PubMed: 32017367
DOI: 10.1111/jth.14756 -
Thrombosis and Haemostasis Nov 2014Endothelial cells express several types of integral membrane protein receptors, which upon interaction and activation by their specific ligands, initiate a signalling... (Review)
Review
Endothelial cells express several types of integral membrane protein receptors, which upon interaction and activation by their specific ligands, initiate a signalling network that links extracellular cues in circulation to various biological processes within a plethora of cells in the vascular system. A small family of G-protein coupled receptors, termed protease-activated receptors (PAR1-4), can be specifically activated by coagulation proteases, thereby modulating a diverse array of cellular activities under various pathophysiological conditions. Thrombin and all vitamin K-dependent coagulation proteases, with the exception of factor IXa for which no PAR signalling has been attributed, can selectively activate cell surface PARs on the vasculature. Thrombin can activate PAR1, PAR3 and PAR4, but not PAR2 which can be specifically activated by factors VIIa and Xa. The mechanistic details of the specificity of PAR signalling by coagulation proteases are the subject of extensive investigation by many research groups worldwide. However, analysis of PAR signalling data in the literature has proved to be challenging since a single coagulation protease can elicit different signalling responses through activation of the same PAR receptor in endothelial cells. This article is focused on briefly reviewing the literature with respect to determinants of the specificity of PAR signalling by coagulation proteases with special emphasis on the mechanism of PAR1 signalling by thrombin and activated protein C in endothelial cells.
Topics: Animals; Blood Coagulation Factors; Endothelial Cells; Enzyme Activation; Human Umbilical Vein Endothelial Cells; Humans; Membrane Microdomains; Models, Biological; NF-kappa B; Protein C; Protein Conformation; Receptors, Proteinase-Activated; Signal Transduction; Thrombin
PubMed: 24990498
DOI: 10.1160/TH14-02-0167 -
Cureus Mar 2020Protein C (PC) is a 62-kD vitamin K dependent glycoprotein produced by the liver as a zymogen and is activated by binding to the thrombin-thrombomodulin complex, with... (Review)
Review
Protein C (PC) is a 62-kD vitamin K dependent glycoprotein produced by the liver as a zymogen and is activated by binding to the thrombin-thrombomodulin complex, with protein S (PS) acting as a cofactor. Among its various functions, PC acts as a naturally occurring anticoagulant and its deficiency, either homozygous or heterozygous, predisposes the individual to a state of thrombosis, particularly venous thromboembolism, and mainfests as myocardial infarction (MI), deep venous thrombosis, pulmonary embolism, or stroke. This review discusses the pathophysiology of the anticoagulatory effect of PC, mode of inheritance of its deficiency, the arterial and venous involvement in patients with stroke, and its risk factors. A detailed analysis of published case reports on PC deficiency as a causative agent of stroke in young adults has also been included along with the management of such patients.
PubMed: 32351850
DOI: 10.7759/cureus.7472 -
Thrombosis Research Mar 2023COVID-19 is associated with an increased thromboembolic risk. However, the mechanisms triggering clot formation in those patients remain unknown.
INTRODUCTION
COVID-19 is associated with an increased thromboembolic risk. However, the mechanisms triggering clot formation in those patients remain unknown.
PATIENTS AND METHODS
In 118 adult Caucasian severe but non-critically ill COVID-19 patients (median age 58 years; 73 % men) and 46 controls, we analyzed in vitro plasma thrombin generation profile (calibrated automated thrombogram [CAT assay]) and investigated thrombophilia-related factors, such as protein C and antithrombin activity, free protein S level, presence of antiphospholipid antibodies and factor V Leiden R506Q and prothrombin G20210A mutations. We also measured circulating von Willebrand factor (vWF) antigen and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) antigen and activity. In patients, blood samples were collected on admission to the hospital before starting any therapy, including heparin. Finally, we examined the relationship between observed alterations and disease follow-up, such as thromboembolic complications.
RESULTS
COVID-19 patients showed 17 % lower protein C activity, 22 % decreased free protein S levels, and a higher prevalence of positive results for IgM anticardiolipin antibodies. They also had 151 % increased vWF, and 27 % decreased ADAMTS13 antigens compared with controls (p < 0.001, all). On the contrary, thrombin generation potential was similar to controls. In the follow-up, pulmonary embolism (PE) occurred in thirteen (11 %) patients. They were characterized by a 55 % elevated D-dimer (p = 0.04) and 2.7-fold higher troponin I (p = 0.002) during hospitalization and 29 % shorter time to thrombin peak in CAT assay (p = 0.009) compared to patients without PE.
CONCLUSIONS
In COVID-19, we documented prothrombotic abnormalities of peripheral blood. PE was characterized by more dynamic thrombin generation growth in CAT assay performed on admittance to the hospital.
Topics: Humans; ADAMTS13 Protein; COVID-19; Protein C; Thrombin; von Willebrand Factor; Protein S
PubMed: 36709678
DOI: 10.1016/j.thromres.2023.01.016 -
Journal of Neuroinflammation Jun 2022Inflammation and coagulation are linked and pathogenic in neuroinflammatory diseases. Protease-activated receptor 1 (PAR1) can be activated both by thrombin, inducing...
BACKGROUND
Inflammation and coagulation are linked and pathogenic in neuroinflammatory diseases. Protease-activated receptor 1 (PAR1) can be activated both by thrombin, inducing increased inflammation, and activated protein C (aPC), inducing decreased inflammation. Modulation of the aPC-PAR1 pathway may prevent the neuroinflammation associated with PAR1 over-activation.
METHODS
We synthesized a group of novel molecules based on the binding site of FVII/aPC to the endothelial protein C receptor (EPCR). These molecules modulate the FVII/aPC-EPCR pathway and are therefore named FEAMs-Factor VII, EPCR, aPC Modulators. We studied the molecular and behavioral effects of a selected FEAM in neuroinflammation models in-vitro and in-vivo.
RESULTS
In a lipopolysaccharide (LPS) induced in-vitro model, neuroinflammation leads to increased thrombin activity compared to control (2.7 ± 0.11 and 2.23 ± 0.13 mU/ml, respectively, p = 0.01) and decreased aPC activity (0.57 ± 0.01 and 1.00 ± 0.02, respectively, p < 0.0001). In addition, increased phosphorylated extracellular regulated kinase (pERK) (0.99 ± 0.13, 1.39 ± 0.14, control and LPS, p < 0.04) and protein kinase B (pAKT) (1.00 ± 0.09, 2.83 ± 0.81, control and LPS, p < 0.0002) levels indicate PAR1 overactivation, which leads to increased tumor necrosis factor-alpha (TNF-α) level (1.00 ± 0.04, 1.35 ± 0.12, control and LPS, p = 0.02). In a minimal traumatic brain injury (mTBI) induced neuroinflammation in-vivo model in mice, increased thrombin activity, PAR1 activation, and TNF-α levels were measured. Additionally, significant memory impairment, as indicated by a lower recognition index in the Novel Object Recognition (NOR) test and Y-maze test (NOR: 0.19 ± 0.06, -0.07 ± 0.09, p = 0.03. Y-Maze: 0.50 ± 0.03, 0.23 ± 0.09, p = 0.02 control and mTBI, respectively), as well as hypersensitivity by hot-plate latency (16.6 ± 0.89, 12.8 ± 0.56 s, control and mTBI, p = 0.01), were seen. FEAM prevented most of the molecular and behavioral negative effects of neuroinflammation in-vitro and in-vivo, most likely through EPCR-PAR1 interactions.
CONCLUSION
FEAM is a promising tool to study neuroinflammation and a potential treatment for a variety of neuroinflammatory diseases.
Topics: Animals; Endothelial Protein C Receptor; Factor VII; Inflammation; Lipopolysaccharides; Mice; Neuroinflammatory Diseases; Protein C; Receptor, PAR-1; Signal Transduction; Thrombin; Tumor Necrosis Factor-alpha
PubMed: 35690769
DOI: 10.1186/s12974-022-02505-y -
Journal of Medicine and Life Jan 2023Miscarriage in the first and second trimesters of pregnancy is very common, and coagulopathy can be a contributing factor. Protein C and S deficiency are rare, inherited...
Miscarriage in the first and second trimesters of pregnancy is very common, and coagulopathy can be a contributing factor. Protein C and S deficiency are rare, inherited disorders that can increase the risk of thrombophilia. Women with these deficiencies have a higher risk of developing blood clots in the placenta, which can lead to placental insufficiency and, ultimately, to a miscarriage. We aimed to compare the levels of protein C and protein S in pregnant females with recurrent first and second-trimester pregnancy loss and normal pregnant females. We performed a detailed history, examination, and various lab tests on a cohort of 40 females with a history of recurrent first and second-trimester abortions visiting an outpatient clinic at a multi-specialty hospital in Kashmir, India. All the findings were compared with 40 women with normal pregnancies. 10% of the participants had low protein C and S levels (P=0.277), out of whom 75% (p<0.001) had intrauterine growth retardation (IUGR) on ultrasound with 67% (p<0.001) having reduced doppler flow in the umbilical artery. 0.05% of participants had isolated protein S deficiency with no concomitant IUGR seen. Patients with protein C and S deficiencies were treated with heparin and progesterone and followed up for pregnancy outcomes. Screening for protein C and S deficiency is mandatory in all cases of recurrent pregnancy loss. Treatment with low molecular weight heparin and progesterone should be initiated to ensure good fetal outcomes and prevent post-partum/postoperative catastrophic venous thromboembolism events.
Topics: Pregnancy; Female; Humans; Abortion, Habitual; Protein C; Pregnant Women; Progesterone; Embryo Loss; Placenta; Fetal Growth Retardation
PubMed: 36873128
DOI: 10.25122/jml-2022-0267 -
Clinical and Applied... Nov 2014The increased risk of cardiovascular and cerebrovascular events in patients with migraine remains unexplained. Prothrombotic states are thought to contribute to this...
The increased risk of cardiovascular and cerebrovascular events in patients with migraine remains unexplained. Prothrombotic states are thought to contribute to this increased risk. The present study aimed to compare the prevalence of prothrombotic states in patients with migraine and headache-free controls. We conducted a case-control study to screen for prothrombotic states protein C, protein S (PS), antithrombin III, factor V Leiden, lupus anticoagulant, anticardiolipin, and anti-β2-glycoprotein 1 antibodies in 101 consecutive patients with migraine and 148 controls. An underlying prothrombotic state was encountered in 11.8% of the patients with migraine, PS deficiency being the most common (4.0%). There was no significant difference in the prevalence of prothrombotic states in patients with migraine compared to controls. Traditional prothrombotic states do not seem to have a higher prevalence in patients with migraine compared to controls.
Topics: Adolescent; Adult; Antibodies, Anticardiolipin; Antithrombin III; Blood Coagulation Disorders; Case-Control Studies; Factor V; Female; Humans; Male; Middle Aged; Migraine Disorders; Protein C; Protein S; beta 2-Glycoprotein I
PubMed: 23637003
DOI: 10.1177/1076029613486538 -
Biochemical and Biophysical Research... Apr 2023Thrombomodulin (TM) is a type I transmembrane glycoprotein mainly expressed on the endothelial cells, where it binds thrombin to form the thrombin-TM complex that can...
Thrombomodulin (TM) is a type I transmembrane glycoprotein mainly expressed on the endothelial cells, where it binds thrombin to form the thrombin-TM complex that can activate protein C and thrombin-activable fibrinolysis inhibitor (TAFI) and induce anticoagulant and anti-fibrinolytic reactions, respectively. Cell activation and injury often sheds microparticles that contain membrane TM, which circulate in biofluids like blood. However, the biological function of circulating microparticle-TM is still unknown even though it has been recognized as a biomarker of endothelial cell injury and damage. In comparison with cell membrane, different phospholipids are exposed on the microparticle surface due to cell membrane ''flip-flop'' upon cell activation and injury. Liposomes can be used as a microparticle mimetics. In this report, we prepared TM-containing liposomes with different phospholipids as surrogates of endothelial microparticle-TM and investigated their cofactor activities. We found that liposomal TM with phosphatidylethanolamine (PtEtn) showed increased protein C activation but decreased TAFI activation in comparison to liposomal TM with phosphatidylcholine (PtCho). In addition, we investigated whether protein C and TAFI compete for the thrombin/TM complex on the liposomes. We found that protein C and TAFI did not compete for the thrombin/TM complex on the liposomes with PtCho alone and with low concentration (5%) of PtEtn and phosphatidylserine (PtSer), but competed each other on the liposomes with higher concentration (10%) of PtEtn and PtSer. These results indicate that membrane lipids affect protein C and TAFI activation and microparticle-TM may have different cofactor activities in comparison to cell membrane TM.
Topics: Protein C; Thrombin; Endothelial Cells; Thrombomodulin; Liposomes; Fibrinolysis
PubMed: 36801612
DOI: 10.1016/j.bbrc.2023.02.024