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Blood Advances Sep 2023A direct regulation of adaptive immunity by the coagulation protease activated protein C (aPC) has recently been established. Preincubation of T cells with aPC for 1...
A direct regulation of adaptive immunity by the coagulation protease activated protein C (aPC) has recently been established. Preincubation of T cells with aPC for 1 hour before transplantation increases FOXP3+ regulatory T cells (Tregs) and reduces acute graft-versus-host disease (aGVHD) in mice, but the underlying mechanism remains unknown. Because cellular metabolism modulates epigenetic gene regulation and plasticity in T cells, we hypothesized that aPC promotes FOXP3+ expression by altering T-cell metabolism. To this end, T-cell differentiation was assessed in vitro using mixed lymphocyte reaction or plate-bound α-CD3/CD28 stimulation, and ex vivo using T cells isolated from mice with aGVHD without and with aPC preincubation, or analyses of mice with high plasma aPC levels. In stimulated CD4+CD25- cells, aPC induces FOXP3 expression while reducing expression of T helper type 1 cell markers. Increased FOXP3 expression is associated with altered epigenetic markers (reduced 5-methylcytosine and H3K27me3) and reduced Foxp3 promoter methylation and activity. These changes are linked to metabolic quiescence, decreased glucose and glutamine uptake, decreased mitochondrial metabolism (reduced tricarboxylic acid metabolites and mitochondrial membrane potential), and decreased intracellular glutamine and α-ketoglutarate levels. In mice with high aPC plasma levels, T-cell subpopulations in the thymus are not altered, reflecting normal T-cell development, whereas FOXP3 expression in splenic T cells is reduced. Glutamine and α-ketoglutarate substitution reverse aPC-mediated FOXP3+ induction and abolish aPC-mediated suppression of allogeneic T-cell stimulation. These findings show that aPC modulates cellular metabolism in T cells, reducing glutamine and α-ketoglutarate levels, which results in altered epigenetic markers, Foxp3 promoter demethylation and induction of FOXP3 expression, thus favoring a Treg-like phenotype.
Topics: Mice; Animals; Ketoglutaric Acids; Protein C; Glutamine; T-Lymphocytes, Regulatory; Epigenesis, Genetic; Forkhead Transcription Factors
PubMed: 37315174
DOI: 10.1182/bloodadvances.2023010083 -
Journal of Medicine and Life Nov 2022This study was conducted to assess the level of proteins C and S in patients with thalassemia intermedia from the Thalassemia Center in Erbil, Iraq. This study aimed to...
This study was conducted to assess the level of proteins C and S in patients with thalassemia intermedia from the Thalassemia Center in Erbil, Iraq. This study aimed to evaluate protein C and S levels in patients with β-thalassemia intermedia and correlate them to different clinical and laboratory parameters. This comprehensive descriptive case-control study was conducted in 2021. Twenty-three thalassemia intermedia patients were recruited. After the participants' demographic data were recorded, plasma levels of both proteins were measured. The acquired files were examined for the 23 patients studied, 48% of whom were female. The mean age of the patients was 16.32 years. The findings show that the proportion of protein C in males was greater than in females, while this percentage contrasts when compared with protein S (ranging between 89-99% and 85-96%, respectively). Concerning age, these two types of protein in children have more value compared to older ages. Only seven people had less than 1,000 ferritins, while the others had higher values. A decrease in proteins C and S was observed in the thalassemia intermediate compared to the control group. There was a significant relationship between the decreased protein C and S levels with splenectomy. Given the significant reduction in protein C and S levels among patients with thalassemia intermediate compared to the control group, there is an increased risk of thromboembolic events in patients with thalassemia intermediate.
Topics: Adolescent; Child; Female; Humans; Male; beta-Thalassemia; Case-Control Studies; Ferritins; Protein C; Protein S; Thromboembolism
PubMed: 36567848
DOI: 10.25122/jml-2021-0316 -
Surfactant protein C mutations and familial pulmonary fibrosis: stuck in a loop on the scenic route.The European Respiratory Journal Jan 2022
Topics: AAA Domain; Humans; Idiopathic Pulmonary Fibrosis; Mutation; Protein C; Surface-Active Agents
PubMed: 35086844
DOI: 10.1183/13993003.02147-2021 -
Seminars in Thrombosis and Hemostasis Nov 2022Thrombotic antiphospholipid syndrome (APS) is a condition in which thrombosis in venous, arterial, and/or small vessels is ascribed to the presence of antiphospholipid... (Review)
Review
Thrombotic antiphospholipid syndrome (APS) is a condition in which thrombosis in venous, arterial, and/or small vessels is ascribed to the presence of antiphospholipid antibodies (aPL). Among the various proposed pathogenic theories to explain thrombotic APS, those involving the interaction between aPL and the protein C system have gained much consensus. Indeed, robust data show an acquired activated protein C resistance (APC-R) in these patients. The role of aPL in this impairment is clear, but the mechanism of action is uncertain, as the type of aPL and to what extent aPL are involved remains a gray area. Lupus anticoagulant (LA) is often associated with APC-R, but antibodies generating LA comprise those directed to β2-glycoprotein I and antiphosphatidylserine/prothrombin. Moreover, the induction of APC-R by aPL requires the presence of phospholipids and is suppressed by the presence of an excess of phospholipids. How phospholipids exposed on the cell membranes work in the system in vivo is unknown. Interestingly, acquired APC-R due to aPL might explain the clinical phenotypes of thrombotic APS. Indeed, the literature reports cases of both venous and arterial thromboembolism as well as skin necrosis, the latter observed in the severe form of protein C deficiency and in catastrophic APS.
Topics: Humans; Protein C; Anticoagulants; Antibodies, Antiphospholipid; Antiphospholipid Syndrome; Lupus Coagulation Inhibitor; Thrombosis; Phospholipids
PubMed: 35021251
DOI: 10.1055/s-0041-1742083 -
Journal of Thrombosis and Thrombolysis May 2024COVID-19 has been associated with alterations in coagulation. Recent reports have shown that protein C and S activities are altered in COVID-19. This may affect the... (Review)
Review
COVID-19 has been associated with alterations in coagulation. Recent reports have shown that protein C and S activities are altered in COVID-19. This may affect the complications and outcome of the disease. However, their exact role in COVID-19 remains uncertain. The aim of the current study was therefore to analyze all papers in the literature on protein C and S activities in COVID-19. We searched three medical electronic databases. Of the 2442 papers, 28 studies were selected for the present meta-analysis. For the meta-analysis, means ± standard deviations with 95% confidence intervals (CI) for protein C and S activities were extracted. Pooled p values were calculated using STATA software. Protein C and S activities were significantly lower in COVID-19 patients than in healthy controls (pooled p values: 0.04 and 0.02, respectively). Similarly, protein C activities were considerably lower in nonsurviving patients (pooled p value = 0.00). There was no association between proteins C or S and thrombosis risk or ICU admission in COVID-19 patients (p value > 0.05). COVID-19 patients may exhibit lower activities of the C and S proteins, which might affect disease outcome; however, additional attention should be given when considering therapeutic strategies for these patients.
PubMed: 38722521
DOI: 10.1007/s11239-024-02971-6 -
Nature Communications Nov 2023The precise modification or functionalization of the protein C-terminus is essential but full of challenges. Herein, a chemical approach to modify the C-terminus is...
The precise modification or functionalization of the protein C-terminus is essential but full of challenges. Herein, a chemical approach to modify the C-terminus is developed by fusing a cysteine protease domain on the C-terminus of the protein of interest, which could achieve the non-enzymatic C-terminal functionalization by InsP-triggered cysteine protease domain self-cleavage. This method demonstrates a highly efficient way to achieve protein C-terminal functionalization and is compatible with a wide range of amine-containing molecules and proteins. Additionally, a reversible C-terminal de-functionalization is found by incubating the C-terminal modified proteins with cysteine protease domain and InsP, providing a tool for protein functionalization and de-functionalization. Last, various applications of protein C-terminal functionalization are provided in this work, as demonstrated by the site-specific assembly of nanobody drug conjugates, the construction of a bifunctional antibody, the C-terminal fluorescent labeling, and the C-terminal transpeptidation and glycosylation.
Topics: Protein C; Proteins; Glycosylation; Cysteine Proteases; Cysteine
PubMed: 37935692
DOI: 10.1038/s41467-023-42977-x -
Journal of the American Heart... Feb 2022Background Five classic thrombophilias have been recognized: factor V Leiden (rs6025), the prothrombin G20210A variant (rs1799963), and protein C, protein S, and...
Background Five classic thrombophilias have been recognized: factor V Leiden (rs6025), the prothrombin G20210A variant (rs1799963), and protein C, protein S, and antithrombin deficiencies. This study aimed to determine the thrombotic risk of classic thrombophilias in a cohort of middle-aged and older adults. Methods and Results Factor V Leiden, prothrombin G20210A and protein-coding variants in the (protein C), (protein S), and (antithrombin) anticoagulant genes were determined in 29 387 subjects (born 1923-1950, 60% women) who participated in the Malmö Diet and Cancer study (1991-1996). The Human Gene Mutation Database was used to define 68 disease-causing mutations. Patients were followed up from baseline until the first event of venous thromboembolism (VTE), death, or Dec 31, 2018. Carriership (n=908, 3.1%) for disease-causing mutations in the , , and genes was associated with incident VTE: Hazard ratio (HR) was 1.6 (95% CI, 1.3-1.9). Variants not in Human Gene Mutation Database were not linked to VTE (HR, 1.1; 95% CI, 0.8-1.5). Heterozygosity for rs6025 and rs1799963 was associated with incident VTE: HR, 1.8 (95% CI, 1.6-2.0) and HR, 1.6 (95% CI, 1.3-2.0), respectively. The HR for carrying 1 classical thrombophilia variant was 1.7 (95% CI, 1.6-1.9). HR was 3.9 (95% CI, 3.1-5.0) for carriers of ≥2 thrombophilia variants. Conclusions The 5 classic thrombophilias are associated with a dose-graded risk of VTE in middle-aged and older adults. Disease-causing variants in the , , and genes were more common than the rs1799963 variant but the conferred genetic risk was comparable with the rs6025 and rs1799963 variants.
Topics: Aged; Anticoagulants; Antithrombins; Cohort Studies; Factor V; Female; Humans; Male; Middle Aged; Mutation; Protein C; Protein S; Prothrombin; Risk Factors; Thrombophilia; Thrombosis; Venous Thromboembolism
PubMed: 35112923
DOI: 10.1161/JAHA.121.023018 -
Anales de Pediatria May 2023The objective of the study was to establish the normal range for the levels of antithrombin (AT), protein C (PC), and protein S (PS) in the first week post birth in...
INTRODUCTION
The objective of the study was to establish the normal range for the levels of antithrombin (AT), protein C (PC), and protein S (PS) in the first week post birth in mother-infant pairings, adjusting for obstetric and perinatal factors, based on 2 different laboratory methods.
METHODS
Determinations were carried out in 83 healthy term neonates and their mothers, establishing 3 postpartum age groups: 1-2 days, 3 days, and 4-7 days.
RESULTS
There were no differences in the levels of any of the proteins between the different age groups in neonates or mothers in the first week post birth. The adjusted analysis found no association with obstetric or perinatal factors. The AT and PC levels were higher in mothers compared to infants (P < .001), while the PS levels were similar in both. Overall, the correlation of maternal and infant protein values was poor, except for the levels of free PS in the first 2 days after delivery. Although we found no differences based on which of the 2 laboratory methods was applied, the absolute values did differ.
Topics: Child, Preschool; Female; Humans; Infant; Infant, Newborn; Pregnancy; Mothers; Postpartum Period; Protein C; Thrombin; Protein S; Antithrombins
PubMed: 37076369
DOI: 10.1016/j.anpede.2023.03.005 -
The Journal of Biological Chemistry Nov 2020Activated protein C is a trypsin-like protease with anticoagulant and cytoprotective properties that is generated by thrombin from the zymogen precursor protein C in a...
Activated protein C is a trypsin-like protease with anticoagulant and cytoprotective properties that is generated by thrombin from the zymogen precursor protein C in a reaction greatly accelerated by the cofactor thrombomodulin. The molecular details of this activation remain elusive due to the lack of structural information. We now fill this gap by providing information on the overall structural organization of these proteins using single molecule FRET and small angle X-ray scattering. Under physiological conditions, both zymogen and protease adopt a conformation with all domains vertically aligned along an axis 76 Å long and maximal particle size of 120 Å. This conformation is stabilized by binding of Ca to the Gla domain and is affected minimally by interaction with thrombin. Hence, the zymogen protein C likely interacts with the thrombin-thrombomodulin complex through a rigid body association that produces a protease with essentially the same structural architecture. This scenario stands in contrast to an analogous reaction in the coagulation cascade where conversion of the zymogen prothrombin to the protease meizothrombin by the prothrombinase complex is linked to a large conformational transition of the entire protein. The presence of rigid epidermal growth factor domains in protein C as opposed to kringles in prothrombin likely accounts for the different conformational plasticity of the two zymogens. The new structural features reported here for protein C have general relevance to vitamin K-dependent clotting factors containing epidermal growth factor domains, such as factors VII, IX, and X.
Topics: Enzyme Precursors; Fluorescence Resonance Energy Transfer; Humans; Particle Size; Protein C; Protein Conformation; Scattering, Small Angle; X-Ray Diffraction
PubMed: 32855236
DOI: 10.1074/jbc.RA120.014789 -
International Journal of Molecular... Sep 2022Platelet and coagulation activation are highly reciprocal processes driven by multi-molecular interactions. Activated platelets secrete several coagulation factors and...
Platelet and coagulation activation are highly reciprocal processes driven by multi-molecular interactions. Activated platelets secrete several coagulation factors and expose phosphatidylserine, which supports the activation of coagulation factor proteins. On the other hand, the coagulation cascade generates known ligands for platelet receptors, such as thrombin and fibrin. Coagulation factor (F)Xa, (F)XIIIa and activated protein C (APC) can also bind to platelets, but the functional consequences are unclear. Here, we investigated the effects of the activated (anti)coagulation factors on platelets, other than thrombin. Multicolor flow cytometry and aggregation experiments revealed that the 'supernatant of (hirudin-treated) coagulated plasma' (SCP) enhanced CRP-XL-induced platelet responses, i.e., integrin αβ activation, P-selectin exposure and aggregate formation. We demonstrated that FXIIIa in combination with APC enhanced platelet activation in solution, and separately immobilized FXIIIa and APC resulted in platelet spreading. Platelet activation by FXIIIa was inhibited by molecular blockade of glycoprotein VI (GPVI) or Syk kinase. In contrast, platelet spreading on immobilized APC was inhibited by PAR1 blockade. Immobilized, but not soluble, FXIIIa and APC also enhanced in vitro adhesion and aggregation under flow. In conclusion, in coagulation, factors other than thrombin or fibrin can induce platelet activation via GPVI and PAR receptors.
Topics: Blood Platelets; Factor XIIIa; Fibrin; Hirudins; P-Selectin; Phosphatidylserines; Platelet Activation; Platelet Aggregation; Platelet Glycoprotein GPIIb-IIIa Complex; Platelet Membrane Glycoproteins; Protein C; Receptor, PAR-1; Syk Kinase; Thrombin
PubMed: 36142125
DOI: 10.3390/ijms231810203