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1.
PLoS One ; 19(7): e0304231, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38985805

RESUMO

Trauma is the leading cause of death in individuals up to 45 years of age. Alterations in platelet function are a critical component of trauma-induced coagulopathy (TIC), yet these changes and the potential resulting dysfunction is incompletely understood. The lack of clinical assays available to explore platelet function in this patient population has hindered detailed understanding of the role of platelets in TIC. The objective of this study was to assess trauma patient ex vivo flow-dependent platelet hemostatic capacity in a microfluidic model. We hypothesized that trauma patients would have flow-regime dependent alterations in platelet function. Blood was collected from trauma patients with level I activations (N = 34) within 60 min of hospital arrival, as well as healthy volunteer controls (N = 10). Samples were perfused through a microfluidic model of injury at venous and arterial shear rates, and a subset of experiments were performed after incubation with fluorescent anti-CD41 to quantify platelets. Complete blood counts were performed as well as plasma-based assays to quantify coagulation times, fibrinogen, and von Willebrand factor (VWF). Exploratory correlation analyses were employed to identify relationships with microfluidic hemostatic parameters. Trauma patients had increased microfluidic bleeding times compared to healthy controls. While trauma patient samples were able to deposit a substantial amount of clot in the model injury site, the platelet contribution to microfluidic hemostasis was attenuated. Trauma patients had largely normal hematology and plasma-based coagulation times, yet had elevated D-Dimer and VWF. Venous microfluidic bleeding time negatively correlated with VWF, D-Dimer, and mean platelet volume (MPV), while arterial microfluidic bleeding time positively correlated with oxygenation. Arterial clot growth rate negatively correlated with red cell count, and positively with mean corpuscular volume (MCV). We observed changes in clot composition in trauma patient samples reflected by significantly diminished platelet contribution, which resulted in reduced hemostatic function in a microfluidic model of vessel injury. We observed a reduction in platelet clot contribution under both venous and arterial flow ex vivo in trauma patient samples. While our population was heterogenous and had relatively mild injury severity, microfluidic hemostatic parameters correlated with different patient-specific data depending on the flow setting, indicating potentially differential mechanistic pathways contributing to platelet hemostatic capacity in the context of TIC. These data were generated with the goal of identifying key features of platelet dysfunction in bleeding trauma patients under conditions of flow and to determine if these features correlate with clinically available metrics, thus providing preliminary surrogate markers of physiological platelet dysfunction to be further studied across larger cohorts. Future studies will continue to explore those relationships and further define mechanisms of TIC and their relationship with patient outcomes.


Assuntos
Plaquetas , Hemostasia , Microfluídica , Ferimentos e Lesões , Humanos , Plaquetas/metabolismo , Masculino , Feminino , Adulto , Ferimentos e Lesões/sangue , Ferimentos e Lesões/complicações , Microfluídica/métodos , Pessoa de Meia-Idade , Transtornos da Coagulação Sanguínea/etiologia , Transtornos da Coagulação Sanguínea/sangue , Fator de von Willebrand/metabolismo , Fibrinogênio/metabolismo , Estudos de Casos e Controles , Tempo de Sangramento
2.
Int J Mol Sci ; 25(13)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-39000402

RESUMO

Von Willebrand factor (VWF) is a multimer with a variable number of protomers, each of which is a head-to-head dimer of two multi-domain monomers. VWF responds to shear through the unfolding and extension of distinct domains, thereby mediating platelet adhesion and aggregation to the injured blood vessel wall. VWF's C1-6 segment uncoils and then the A2 domain unfolds and extends in a hierarchical and sequential manner. However, it is unclear whether there is any reservoir of further extensibility. Here, we explored the presence of cryptic extensibility in VWF by nanodissecting individual, pre-stretched multimers with atomic force microscopy (AFM). The AFM cantilever tip was pressed into the surface and moved in a direction perpendicular to the VWF axis. It was possible to pull out protein loops from VWF, which resulted in a mean contour length gain of 217 nm. In some cases, the loop became cleaved, and a gap was present along the contour. Frequently, small nodules appeared in the loops, indicating that parts of the nanodissected VWF segment remained folded. After analyzing the nodal structure, we conclude that the cryptic extensibility lies within the C1-6 and A1-3 regions. Cryptic extensibility may play a role in maintaining VWF's functionality in extreme shear conditions.


Assuntos
Microscopia de Força Atômica , Fator de von Willebrand , Fator de von Willebrand/química , Fator de von Willebrand/metabolismo , Humanos , Multimerização Proteica , Domínios Proteicos
3.
Blood Coagul Fibrinolysis ; 35(5): 256-264, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38973517

RESUMO

Normally, von Willebrand factor (VWF) remains inactive unless its A1A2 domains undergo a shear stress-triggered conformational change. We demonstrated the capacity of a recombinant A2 domain of VWF to bind and to affect fibrin formation, altering the fibrin clot structure. The data indicated that VWF contains an additional binding site for fibrin in the A2 domain that plays a role in the incorporation of VWF to the polymerizing fibrin. This study is to examine the hypothesis that active plasma VWF directly influence fibrin polymerization and the structure of fibrin clots. The study used healthy and type 3 von Willebrand disease (VWD) plasma, purified plasma VWF, fibrin polymerization assays, confocal microscopy and scanning electron microscopy. The exposed A2 domain in active VWF harbors additional binding sites for fibrinogen, and significantly potentiates fibrin formation (P < 0.02). Antibody against the A2 domain of VWF significantly decreased the initial rate of change of fibrin formation (P < 0.002). Clot analyses revealed a significant difference in porosity between normal and type 3 VWD plasma (P < 0.008), further supported by scanning electron microscopy, which demonstrated thicker fibrin fibers in the presence of plasma VWF (P < 0.0003). Confocal immunofluorescence microscopy showed punctate VWF staining along fibrin fibrils, providing visual evidence of the integration of plasma VWF into the fibrin matrix. The study with type 3 VWD plasma supports the hypothesis that plasma VWF directly influences fibrin polymerization and clot structure. In addition, a conformational change in the A1A2 domains exposes a hidden fibrin(ogen) binding site, indicating that plasma VWF determines the fibrin clot structure.


Assuntos
Fibrina , Fator de von Willebrand , Fator de von Willebrand/metabolismo , Humanos , Fibrina/metabolismo , Fibrina/ultraestrutura , Doença de von Willebrand Tipo 3/sangue , Sítios de Ligação , Microscopia Eletrônica de Varredura/métodos
5.
AAPS J ; 26(4): 81, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38992298

RESUMO

Lack of Factor VIII (FVIII) concentrates is one of limiting factors for Hemophilia A prophylaxis in resource-limited countries. Rondaptivon pegol (BT200) is a pegylated aptamer and has been shown to elevate the level of von Willebrand Factor (VWF) and FVIII in previous studies. A population pharmacokinetic model for BT200 was built and linked to the kinetic models of VWF and FVIII based on reasonable assumptions. The developed PK/PD model for BT200 described the observed kinetic of BT200, VWF, and FVIII in healthy volunteers and patients with mild-to-moderate hemophilia A from two clinical trials. The developed model was evaluated using an external dataset in patients with severe hemophilia A taking recombinant FVIII products. The developed and evaluated PK/PD model was able to describe and predict concentration-time profiles of BT200, VWF, and FVIII in healthy volunteers and patients with hemophilia A. Concentration-time profiles of FVIII were then predicted following coadministration of plasma-derived FVIII concentrate and BT200 under various dosing scenarios in virtual patients with severe hemophilia A. Plasma-derived products, that contain VWF, are more accessible in low-resource countries as compared to their recombinant counterparts. The predicted time above 1 and 3 IU/dL FVIII in one week was compared between scenarios in the absence and presence of BT200. A combination dose of 6 mg BT200 once weekly plus 10 IU/kg plasma-derived FVIII twice weekly maintained similar coverage to a 30 IU/kg FVIII thrice weekly dose in absence of BT200, representing only 22% of the FVIII dose per week.


Assuntos
Fator VIII , Hemofilia A , Fator de von Willebrand , Humanos , Fator VIII/farmacocinética , Fator VIII/administração & dosagem , Hemofilia A/tratamento farmacológico , Hemofilia A/sangue , Fator de von Willebrand/farmacocinética , Fator de von Willebrand/administração & dosagem , Modelos Biológicos , Adulto , Masculino , Adulto Jovem , Cinética , Polietilenoglicóis/farmacocinética , Polietilenoglicóis/administração & dosagem , Adolescente
6.
Pediatr Crit Care Med ; 25(7 Suppl 1): e35-e43, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38959358

RESUMO

OBJECTIVES: To derive systematic review informed, modified Delphi consensus regarding monitoring and replacement of specific coagulation factors during pediatric extracorporeal membrane oxygenation (ECMO) support for the Pediatric ECMO Anticoagulation CollaborativE. DATA SOURCES: A structured literature search was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021. STUDY SELECTION: Included studies assessed monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric ECMO support. DATA EXTRACTION: Two authors reviewed all citations independently, with conflicts resolved by a third reviewer if required. Twenty-nine references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form. DATA SYNTHESIS: Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. A panel of 48 experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. We developed one weak recommendation and four expert consensus statements. CONCLUSIONS: There is insufficient evidence to formulate recommendations on monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric patients on ECMO. Optimal monitoring and parameters for replacement of key hemostasis parameters is largely unknown.


Assuntos
Antitrombinas , Técnica Delphi , Oxigenação por Membrana Extracorpórea , Fibrinogênio , Fator de von Willebrand , Oxigenação por Membrana Extracorpórea/métodos , Humanos , Fibrinogênio/análise , Antitrombinas/uso terapêutico , Criança , Fator de von Willebrand/análise , Anticoagulantes/administração & dosagem , Anticoagulantes/uso terapêutico
7.
J Cell Mol Med ; 28(13): e18457, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38963011

RESUMO

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) can potentially cure malignant blood disorders and benign conditions such as haemoglobinopathies and immunologic diseases. However, allo-HSCT is associated with significant complications. The most common and debilitating among them is graft-versus-host disease (GVHD). In GVHD, donor-derived T cells mount an alloimmune response against the recipient. The alloimmune response involves several steps, including recognition of recipient antigens, activation and proliferation of T cells in secondary lymphoid organs, and homing into GVHD-targeted organs. Adhesion molecules on T cells and endothelial cells mediate homing of T cells into lymphoid and non-lymphoid tissues. In this study, we showed that Von Willebrand factor (VWF), an adhesion molecule secreted by activated endothelial cells, plays an important role in mouse models of GVHD. We investigated the effect of the VWF-cleaving protease ADAMTS13 on GVHD. We found that ADAMTS13 reduced the severity of GVHD after bone marrow transplantation from C57BL6 donor to BALB/C recipient mice. A recombinant VWF-A2 domain peptide also reduced GVHD in mice. We showed that ADAMTS13 and recombinant VWF-A2 reduced the binding of T cells to endothelial cells and VWF in vitro, and reduced the number of T cells in lymph nodes, Peyer's patches and GVHD-targeted organs in vivo. We identified LFA-1 (αLß2) as the binding site of VWF on T cells. Our results showed that blocking T-cell homing by ADAMTS13 or VWF-A2 peptide reduced the severity of the GVHD after allo-HSCT, a potentially novel method for treating and preventing GVHD.


Assuntos
Proteína ADAMTS13 , Doença Enxerto-Hospedeiro , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Linfócitos T , Fator de von Willebrand , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/imunologia , Animais , Proteína ADAMTS13/metabolismo , Camundongos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Fator de von Willebrand/metabolismo , Humanos , Transplante Homólogo , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Modelos Animais de Doenças , Transplante de Medula Óssea , Células Endoteliais/metabolismo
8.
Zhonghua Gan Zang Bing Za Zhi ; 32(6): 484-488, 2024 Jun 20.
Artigo em Chinês | MEDLINE | ID: mdl-38964888

RESUMO

Portal vein thrombosis (PVT) is divided into cirrhotic and non-cirrhotic PVTs. The incidence rate of PVT varies greatly among different clinical stages of cirrhosis, with an overall incidence rate of about 13.92%, and the prevalence of cirrhotic PVT following splenectomy is as high as 60%. The pathogenesis of cirrhotic PVT is still unclear. However, the activation of Janus kinase/signal transduction and activator transcription signaling pathways, the rise in the expression of von Willebrand factor, and the gut microbiota along with its metabolite trimethylamine-N-oxide play an important role in the injury of vascular endothelial cells and the formation of PVT in cirrhosis. Therefore, these could be a new target for cirrhotic PVT prevention and treatment.


Assuntos
Cirrose Hepática , Veia Porta , Trombose Venosa , Humanos , Trombose Venosa/etiologia , Trombose Venosa/prevenção & controle , Cirrose Hepática/complicações , Transdução de Sinais , Metilaminas/metabolismo , Microbioma Gastrointestinal , Fator de von Willebrand/metabolismo , Janus Quinases/metabolismo
9.
BMC Pulm Med ; 24(1): 325, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965511

RESUMO

BACKGROUND: SARS-CoV-2 is a systemic disease that affects endothelial function and leads to coagulation disorders, increasing the risk of mortality. Blood levels of endothelial biomarkers such as Von Willebrand Factor (VWF), Thrombomodulin or Blood Dendritic Cell Antigen-3 (BDCA3), and uUokinase (uPA) increase in patients with severe disease and can be prognostic indicators for mortality. Therefore, the aim of this study was to determine the effect of VWF, BDCA3, and uPA levels on mortality. METHODS: From May 2020 to January 2021, we studied a prospective cohort of hospitalized adult patients with polymerase chain reaction (PCR)-confirmed COVID-19 with a SaO2 ≤ 93% and a PaO2/FiO2 ratio < 300. In-hospital survival was evaluated from admission to death or to a maximum of 60 days of follow-up with Kaplan-Meier survival curves and Cox proportional hazard models as independent predictor measures of endothelial dysfunction. RESULTS: We recruited a total of 165 subjects (73% men) with a median age of 57.3 ± 12.9 years. The most common comorbidities were obesity (39.7%), hypertension (35.4%) and diabetes (30.3%). Endothelial biomarkers were increased in non-survivors compared to survivors. According to the multivariate Cox proportional hazard model, those with an elevated VWF concentration ≥ 4870 pg/ml had a hazard ratio (HR) of 4.06 (95% CI: 1.32-12.5) compared to those with a lower VWF concentration adjusted for age, cerebrovascular events, enoxaparin dose, lactate dehydrogenase (LDH) level, and bilirubin level. uPA and BDCA3 also increased mortality in patients with levels ≥ 460 pg/ml and ≥ 3600 pg/ml, respectively. CONCLUSION: The risk of mortality in those with elevated levels of endothelial biomarkers was observable in this study.


Assuntos
Biomarcadores , COVID-19 , Trombomodulina , Ativador de Plasminogênio Tipo Uroquinase , Fator de von Willebrand , Humanos , COVID-19/mortalidade , COVID-19/sangue , Masculino , Fator de von Willebrand/metabolismo , Fator de von Willebrand/análise , Pessoa de Meia-Idade , Feminino , Biomarcadores/sangue , Idoso , Ativador de Plasminogênio Tipo Uroquinase/sangue , Trombomodulina/sangue , Estudos Prospectivos , Prognóstico , SARS-CoV-2 , Adulto , Endotélio Vascular/fisiopatologia , Mortalidade Hospitalar , Modelos de Riscos Proporcionais
10.
Front Endocrinol (Lausanne) ; 15: 1397062, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38836224

RESUMO

Background and aims: A prothrombotic state was demonstrated in patients with Cushing's syndrome and is involved in the development and progression of cardiovascular and renal damage in hypertensive patients. This study was designed to examine the relationships between cortisol secretion and the hemostatic and fibrinolytic systems in hypertension. Methods: In 149 middle-aged, nondiabetic, essential hypertensive patients free of cardiovascular and renal complications, we measured hemostatic markers that express the spontaneous activation of the coagulation and fibrinolytic systems and assessed daily cortisol levels (8 AM, 3 PM, 12 AM; area under the curve, AUC-cortisol) together with the cortisol response to dexamethasone overnight suppression (DST-cortisol). Results: Plasma levels of D-dimer (D-dim), prothrombin fragment 1 + 2 (F1 + 2), and von Willebrand factor (vWF) were progressively and significantly higher across tertiles of AUC-cortisol and DST-cortisol, whereas no differences were observed in fibrinogen, tissue plasminogen activator, plasminogen activator inhibitor-1, antithrombin III, protein C, and protein S. D-dim, F1 + 2, and vWF were significantly and directly correlated with age and both AUC-cortisol and DST-cortisol. Multivariate regression analysis showed that both AUC-cortisol and DST-cortisol were related to plasma D-dim, F1 + 2, and vWF independently of age, body mass index, blood pressure, and renal function. Conclusion: Greater daily cortisol profile and cortisol response to overnight suppression are independently associated with a prothrombotic state in hypertensive patients and might contribute to the development of organ damage and higher risk of cardiovascular complications.


Assuntos
Dexametasona , Hidrocortisona , Hipertensão , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Hidrocortisona/sangue , Hipertensão/sangue , Hipertensão/complicações , Adulto , Trombose/sangue , Trombose/etiologia , Fator de von Willebrand/metabolismo , Fator de von Willebrand/análise , Ritmo Circadiano/fisiologia , Idoso , Biomarcadores/sangue
11.
Mar Drugs ; 22(6)2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38921594

RESUMO

Endothelial hyperpermeability is pivotal in sepsis-associated multi-organ dysfunction. Increased von Willebrand factor (vWF) plasma levels, stemming from activated platelets and endothelium injury during sepsis, can bind to integrin αvß3, exacerbating endothelial permeability. Hence, targeting this pathway presents a potential therapeutic avenue for sepsis. Recently, we identified isaridin E (ISE), a marine-derived fungal cyclohexadepsipeptide, as a promising antiplatelet and antithrombotic agent with a low bleeding risk. ISE's influence on septic mortality and sepsis-induced lung injury in a mouse model of sepsis, induced by caecal ligation and puncture, is investigated in this study. ISE dose-dependently improved survival rates, mitigating lung injury, thrombocytopenia, pulmonary endothelial permeability, and vascular inflammation in the mouse model. ISE markedly curtailed vWF release from activated platelets in septic mice by suppressing vesicle-associated membrane protein 8 and soluble N-ethylmaleide-sensitive factor attachment protein 23 overexpression. Moreover, ISE inhibited healthy human platelet adhesion to cultured lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVECs), thereby significantly decreasing vWF secretion and endothelial hyperpermeability. Using cilengitide, a selective integrin αvß3 inhibitor, it was found that ISE can improve endothelial hyperpermeability by inhibiting vWF binding to αvß3. Activation of the integrin αvß3-FAK/Src pathway likely underlies vWF-induced endothelial dysfunction in sepsis. In conclusion, ISE protects against sepsis by inhibiting endothelial hyperpermeability and platelet-endothelium interactions.


Assuntos
Plaquetas , Células Endoteliais da Veia Umbilical Humana , Sepse , Fator de von Willebrand , Animais , Sepse/tratamento farmacológico , Fator de von Willebrand/metabolismo , Humanos , Camundongos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Masculino , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Integrina alfaVbeta3/metabolismo , Integrina alfaVbeta3/antagonistas & inibidores , Permeabilidade Capilar/efeitos dos fármacos
12.
Thromb Res ; 240: 109038, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38850807

RESUMO

BACKGROUND: Shiga toxin (Stx) can activate inflammatory signaling, leading to vascular dysfunction and promotion of a pro-thrombotic tissue microenvironment. Stx can trigger the development of the enterohemorrhagic (childhood) hemolytic uremic syndrome (eHUS), a triad of thrombocytopenia, hemolytic anemia, and acute kidney injury, often requiring dialysis. Additional features may include damage to other organs, including the gastrointestinal tract, pancreas, brain and cardiovascular system; death occurs in 2-5 %. eHUS is a thrombotic microangiopathy; thus, endothelial cell (EC) injury and platelet fibrin thrombus formation in glomerular arterioles and in the arterioles of other affected organs are likely. To elucidate mechanisms of this microangiopathy, we examined in human ECs the regulation of the platelet adhesion proteins P-selectin and von Willebrand factor (VWF), along with the downregulation of erythroblast-transformation-specific transcription factor (ERG) a key regulator of angiogenesis and megakaryocyte development. METHODS: VWF, P-selectin, and ERG levels were determined using immunofluorescence and Western blot in human umbilical endothelial cells (HUVECs). HUVECs were treated with tumor necrosis factor-alpha (TNF-α), Stx-1 or both, versus normal controls. Capillary morphogenesis on Matrigel was performed using HUVECs treated, for 22 h with TNF-α, Stx-1, or both, or treated 4 h with Stx-1 alone or in combination with TNF-α for 22 h. RESULTS: Stx-1 significantly reduced ERG and VWF expression on HUVECs, but upregulated P-selectin expression. ERG levels decreased with Stx-1 alone or in combination with TNF-α, in the nuclear, perinuclear and cytoplasmatic regions. Stx-1 reduced capillary morphogenesis, while Stx-1-TNF-α combined treatment reduced capillary morphogenesis still further. CONCLUSIONS: In the presence of Stx-1 or TNF-α or both treatments, ECs were activated, expressing higher levels of P-selectin and lower levels of VWF. Our findings, further, provide evidence that Stx-1 downregulates ERG, repressing angiogenesis in vitro.


Assuntos
Regulação para Baixo , Células Endoteliais da Veia Umbilical Humana , Humanos , Regulação para Baixo/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Regulador Transcricional ERG/metabolismo , Toxina Shiga/metabolismo , Toxina Shiga/farmacologia , Células Endoteliais/metabolismo , Células Endoteliais/efeitos dos fármacos , Fator de von Willebrand/metabolismo , Angiogênese
13.
Thromb Res ; 240: 109061, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38870771

RESUMO

BACKGROUND: Von Willebrand Disease (VWD) is the most common inherited bleeding disorder. VWD is characterized by an abnormal quantity or quality of von Willebrand Factor (VWF). Anemia is often found at presentation for a bleeding disorder evaluation due to chronic blood loss. OBJECTIVES/HYPOTHESIS: We hypothesized that anemia is associated with elevations in both VWF and factor VIII (FVIII) over baseline. We also hypothesized that obesity would be associated with increased levels of VWF. METHODS: We conducted a single-center review of the electronic health record for patients that had proximal von Willebrand profiles and Hb data. RESULTS: We identified 4552 unique subjects with VWF studies and a CBC within 24 h. We found that decreasing hemoglobin inversely correlated with VWF antigen, VWF ristocetin cofactor activity, and FVIII activity. We also found that obesity and Black race were independently associated with increased VWF antigen, activity, and FVIII activity. Hb, race, and body mass index (BMI) continued to be determinants of VWF and FVIII levels in multivariable analysis. CONCLUSION: Our study demonstrates that anemia, race, and BMI were found to be associated with elevation of VWF antigen, VWF activity, and FVIII levels. As many individuals with anemia present for evaluation for a bleeding disorder, these variables need to be considered. KEY POINTS: - Anemia was found to be associated with elevation of VWF antigen, VWF activity and FVIII levels. - Testing von Willebrand factor at times of anemia may mask a diagnosis of von Willebrand Disease.


Assuntos
Índice de Massa Corporal , Fator VIII , Hemoglobinas , Fator de von Willebrand , Humanos , Fator de von Willebrand/análise , Fator de von Willebrand/metabolismo , Fator VIII/análise , Fator VIII/metabolismo , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Hemoglobinas/análise , Doenças de von Willebrand/sangue , Anemia/sangue , Idoso , Obesidade/sangue , Obesidade/complicações
14.
Expert Rev Hematol ; 17(7): 391-403, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38889268

RESUMO

BACKGROUND: Platelet storage is complicated by deleterious changes, among which reduction of ristocetin-induced platelet aggregation (RIPA) has a poorly understood mechanism. The study elucidates the mechanistic roles of all the possible players in this process. RESEARCH DESIGN AND METHODS: PRP-platelet concentrates were subjected to RIPA, collagen-induced platelet aggregation (CIPA), and flowcytometric analysis of GPIbα and PAC-1 binding from days 0 to 5 of storage. Platelet-poor plasma was subjected to colorimetric assays for glucose/LDH evaluation and automatic analyzer to examine VWF antigen and activity. RESULTS: From day three of platelet storage, reducing CIPA but not RIPA was correlated with the reduction of both metabolic state and integrin activity. RIPA reduction was directly related to the decreased levels of total-content/expression of GPIbα, and inversely related to its shedding levels during storage. Re-suspension of 5-day stored platelet in fresh plasma compensated CIPA, but not RIPA. VWF concentration and its activity did not change during storage while they had no correlation with RIPA. CONCLUSIONS: This study identified the irreversible loss of platelet GPIbα, but not VWF status, as the primary cause of the storage-dependent decrease of RIPA. Unlike CIPA, this observation was not compensated by plasma refreshment, suggesting that some evidence of PSL may not be recovered after transfusion.


Assuntos
Plaquetas , Preservação de Sangue , Agregação Plaquetária , Complexo Glicoproteico GPIb-IX de Plaquetas , Ristocetina , Fator de von Willebrand , Humanos , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Agregação Plaquetária/efeitos dos fármacos , Ristocetina/farmacologia , Plaquetas/metabolismo , Preservação de Sangue/métodos , Fator de von Willebrand/metabolismo , Hemostasia/efeitos dos fármacos
15.
Sci Rep ; 14(1): 14524, 2024 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-38914598

RESUMO

NLRP3 inflammasome has been implicated in neutrophil polarization and extrusion of neutrophil extracellular traps (NETs) in vitro and facilitates secretion of Il1-beta (IL-1ß). Permanent ligation of the left anterior descending artery was used to induce MI in WT and NLRP3-/- mice as well as in NLRP3-/- recipient mice transfused with either WT or NLRP3-/- neutrophils. NLRP3 deficiency reduced infarct size to roughly a third of WT heart injury and preserved left ventricular (LV) function at 12 h after MI as assessed by echocardiography and triphenyltetrazolium chloride staining of live tissue. Transfusion of WT but not NLRP3-/- neutrophils after MI increased infarct size in NLRP3-/- mice and significantly reduced LV function. The key features of myocardial tissue in WT neutrophil transfused recipients were increased H3Cit-positive deposits with NET-like morphology and increased tissue levels of IL-1ß and plasma levels of von Willebrand Factor (VWF). Flow cytometry analysis also revealed that neutrophil NLRP3 increased the number of labeled and transfused neutrophils in the bone marrow of recipient mice following MI. Our data suggest a key role for neutrophil NLRP3 in the production of IL-1ß and deposition of NETs in cardiac tissue exacerbating injury following MI. We provide evidence for a link between neutrophil NLRP3 and VWF release likely enhancing thromboinflammation in the heart. Neutrophil NLRP3 deficiency conferred similar cardioprotective effects to general NLRP3 deletion in MI rendering anti-neutrophil NLRP3 therapy a promising target for early cardioprotective treatment.


Assuntos
Armadilhas Extracelulares , Interleucina-1beta , Camundongos Knockout , Infarto do Miocárdio , Miocárdio , Proteína 3 que Contém Domínio de Pirina da Família NLR , Neutrófilos , Fator de von Willebrand , Animais , Masculino , Camundongos , Modelos Animais de Doenças , Armadilhas Extracelulares/metabolismo , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Neutrófilos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Fator de von Willebrand/metabolismo , Fator de von Willebrand/genética
16.
Immun Inflamm Dis ; 12(6): e1267, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38888384

RESUMO

OBJECTIVES: Acute pancreatitis (AP) is an inflammatory disease of the pancreas, and the prognosis of severe AP (SAP) is poor. The study aimed to identify promising biomarkers for predicting the occurrence and survival outcome of SAP patients. MATERIALS AND METHODS: Two hundred and forty AP patients were retrospectively recruited, in which 72 cases with SAP. Blood test was done for collection of laboratory indicators. After treatment, the mortality of patients was recorded. RESULTS: Patients in the SAP group had higher intensive care unit admissions and longer hospital stays (p < .001). Among laboratory parameters, significantly high values of C-reactive protein (CRP), triglycerides and glucose (TyG) index, Von willebrand factor antigen (vWF:Ag) and D-dimer were found in SAP groups relative to non-SAP ones. Receiver operating characteristic curve indicated the good performance of CRP, TyG index, vWF:Ag and D-dimer in SAP diagnosis. Among all SAP cases, 51 survived while 21 died. TyG index (odds ratio [OR] = 6.914, 95% confidence interval [CI] = 1.193-40.068, p = .028), vWF:Ag (OR = 7.441, 95% CI = 1.236-244.815, p = .028), and D-dimer (OR = 7.987, 95% CI = 1.251-50.997, p = .028) were significantly related to survival outcome of SAP patients by multiple logistic regression analysis. Both TyG index and vWF showed favorable efficiency in predicting overall prognosis. The area under the curve for the multivariate model (PRE = -35.908 + 2.764 × TyG + 0.021 × vWF:Ag) was 0.909 which was greater than 0.9, indicating its excellent performance in prognosis prediction. CONCLUSION: CRP, TyG index, vWF:Ag, and D-dimer values on admission may be potential clinical predictors of the development of SAP. Moreover, TyG index and vWF:Ag may be helpful to predict survival outcome.


Assuntos
Biomarcadores , Proteína C-Reativa , Produtos de Degradação da Fibrina e do Fibrinogênio , Pancreatite , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Pancreatite/mortalidade , Pancreatite/sangue , Pancreatite/diagnóstico , Estudos Retrospectivos , Prognóstico , Adulto , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Proteína C-Reativa/análise , Proteína C-Reativa/metabolismo , Biomarcadores/sangue , Idoso , Fator de von Willebrand/metabolismo , Fator de von Willebrand/análise , Curva ROC , Doença Aguda , Triglicerídeos/sangue , Glicemia/metabolismo , Glicemia/análise , Índice de Gravidade de Doença
17.
Expert Rev Hematol ; 17(7): 341-351, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38752747

RESUMO

INTRODUCTION: Hereditary thrombotic thrombocytopenic purpura (hTTP) is caused by deficiency of plasma ADAMTS13 activity, resulting from ADAMTS13 mutations. ADAMTS13 cleaves ultra large von Willebrand factor (VWF), thus reducing its multimer sizes. Hereditary deficiency of plasma ADAMTS13 activity leads to the formation of excessive platelet-VWF aggregates in small arterioles and capillaries, resulting in hTTP. AREAS COVERED: PubMed search from 1956 to 2024 using thrombotic thrombocytopenic purpura and therapy identified 3,675 articles. Only the articles relevant to the topic were selected for discussion, which focuses on pathophysiology, clinical presentations, and mechanisms of action of emerging therapeutics for hTTP. Current therapies include infusion of plasma, or coagulation factor VIII, or recombinant ADAMTS13. Emerging therapies include anti-VWF A1 aptamers or nanobody and gene therapies with adeno-associated viral vector or self-inactivated lentiviral vector or a sleeping beauty transposon system for a long-term expression of a functional ADAMTS13 enzyme. EXPERT OPINION: Frequent plasma infusion remains to be the standard of care in most parts of the world, while recombinant ADAMTS13 has become the treatment of choice for hTTP in some of the Western countries. The success of gene therapies in preclinical models may hold a promise for future development of these novel approaches for a cure of hTTP.


Assuntos
Proteína ADAMTS13 , Terapia Genética , Púrpura Trombocitopênica Trombótica , Humanos , Púrpura Trombocitopênica Trombótica/terapia , Púrpura Trombocitopênica Trombótica/genética , Proteína ADAMTS13/genética , Proteína ADAMTS13/metabolismo , Proteína ADAMTS13/deficiência , Fator de von Willebrand/metabolismo , Fator de von Willebrand/genética , Anticorpos de Domínio Único/uso terapêutico , Gerenciamento Clínico , Fator VIII/genética , Fator VIII/uso terapêutico , Fator VIII/metabolismo , Mutação , Animais
18.
J Thromb Haemost ; 22(7): 2052-2058, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38704122

RESUMO

BACKGROUND: The activity of von Willebrand factor (VWF) in facilitating platelet adhesion and aggregation correlates with its multimer size. Traditional ristocetin-dependent functional assays lack sensitivity to multimer sizes. Recently, nanobodies targeting the autoinhibitory module and activating VWF were identified. OBJECTIVES: To develop an assay that can differentiate the platelet-binding activity of VWF multimers. METHODS: A novel enzyme-linked immunosorbent assay (nanobody-triggered glycoprotein Ib binding assay [VWF:GPIbNab]) utilizing a VWF-activating nanobody was developed. Recombinant VWF, plasma-derived VWF (pdVWF), and selected gel-filtrated fractions of pdVWF were evaluated for VWF antigen and activity levels. A linear regression model was developed to estimate the specific activity of VWF multimers. RESULTS: Of the 3 activating nanobodies tested, 6C11 with the lowest activation effect exhibited the highest sensitivity for high-molecular-weight multimers (HMWMs) of VWF. VWF:GPIbNab utilizing 6C11 (VWF:GPIbNab6C11) produced significantly higher activity/antigen ratios for recombinant VWF (>2.0) and HMWM-enriched pdVWF fractions (>2.0) than for pdVWF (∼1.0) or fractions enriched with shorter multimers (<1.0). The differences were much larger than those produced by VWF:GPIbNab utilizing other nanobodies, VWF:GPIbM, VWF:GPIbR, or VWF:CB assays. Linear regression analysis of 5 pdVWF fractions of various multimer sizes produced an estimated specific activity of 2.7 for HMWMs. The analysis attributed >90% of the VWF activity measured by VWF:GPIbNab6C11 to that of HMWMs, which is significantly higher than all other activity assays tested. CONCLUSION: The VWF:GPIbNab6C11 assay exhibits higher sensitivity to HMWMs than ristocetin-based and collagen-binding assays. Future studies examining the application of this assay in clinical settings and any associated therapeutic benefit of doing so are warranted.


Assuntos
Ensaio de Imunoadsorção Enzimática , Multimerização Proteica , Anticorpos de Domínio Único , Fator de von Willebrand , Fator de von Willebrand/metabolismo , Fator de von Willebrand/análise , Humanos , Anticorpos de Domínio Único/imunologia , Anticorpos de Domínio Único/química , Modelos Lineares , Proteínas Recombinantes , Plaquetas/metabolismo , Agregação Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Ligação Proteica , Adesividade Plaquetária , Peso Molecular
19.
Blood Adv ; 8(13): 3388-3401, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38701351

RESUMO

ABSTRACT: Glycoprotein Ibα (GPIbα), the ligand-binding subunit of platelet GPIb-IX complex, interacts with von Willebrand factor (VWF) exposed at the injured vessel wall, initiating platelet adhesion, activation, hemostasis, and thrombus formation. The cytoplasmic tail of GPIbα interacts with 14-3-3ζ, regulating the VWF-GPIbα-elicited signal transduction and VWF binding function of GPIbα. However, we unexpectedly found that the GPIbα-14-3-3ζ association, beyond VWF-dependent function, is essential for general platelet activation. We found that the myristoylated peptide of GPIbα C-terminus MPαC, a potential GPIbα inhibitor, by itself induced platelet aggregation, integrin αIIbß3 activation, granule secretion, and phosphatidylserine (PS) exposure. Conversely, the deletion of the cytoplasmic tail of GPIbα in mouse platelets (10aa-/-) decreased platelet aggregation, integrin αIIbß3 activation, granule secretion, and PS exposure induced by various physiological agonists. Phosphoproteome-based kinase activity profiling revealed significantly upregulated protein kinase C (PKC) activity in MPαC-treated platelets. MPαC-induced platelet activation was abolished by the pan-PKC inhibitor and PKCα deletion. Decreased PKC activity was observed in both resting and agonist-stimulated 10aa-/- platelets. GPIbα regulates PKCα activity by sequestering 14-3-3ζ from PKCα. In vivo, the deletion of the GPIbα cytoplasmic tail impaired mouse hemostasis and thrombus formation and protected against platelet-dependent pulmonary thromboembolism. Therefore, our findings demonstrate an essential role for the GPIbα cytoplasmic tail in regulating platelet general activation and thrombus formation beyond the VWF-GPIbα axis.


Assuntos
Plaquetas , Ativação Plaquetária , Complexo Glicoproteico GPIb-IX de Plaquetas , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Animais , Camundongos , Humanos , Plaquetas/metabolismo , Proteínas 14-3-3/metabolismo , Fator de von Willebrand/metabolismo , Trombose/metabolismo , Transdução de Sinais , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Camundongos Knockout , Agregação Plaquetária
20.
J Transl Med ; 22(1): 412, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38693516

RESUMO

BACKGROUND: Thromboinflammation involving platelet adhesion to endothelial surface-associated von Willebrand factor (VWF) has been implicated in the accelerated progression of non-culprit plaques after MI. The aim of this study was to use arterial endothelial molecular imaging to mechanistically evaluate endothelial-associated VWF as a therapeutic target for reducing remote plaque activation after myocardial infarction (MI). METHODS: Hyperlipidemic mice deficient for the low-density lipoprotein receptor and Apobec-1 underwent closed-chest MI and were treated chronically with either: (i) recombinant ADAMTS13 which is responsible for proteolytic removal of VWF from the endothelial surface, (ii) N-acetylcysteine (NAC) which removes VWF by disulfide bond reduction, (iii) function-blocking anti-factor XI (FXI) antibody, or (iv) no therapy. Non-ischemic controls were also studied. At day 3 and 21, ultrasound molecular imaging was performed with probes targeted to endothelial-associated VWF A1-domain, platelet GPIbα, P-selectin and vascular cell adhesion molecule-1 (VCAM-1) at lesion-prone sites of the aorta. Histology was performed at day 21. RESULTS: Aortic signal for P-selectin, VCAM-1, VWF, and platelet-GPIbα were all increased several-fold (p < 0.01) in post-MI mice versus sham-treated animals at day 3 and 21. Treatment with NAC and ADAMTS13 significantly attenuated the post-MI increase for all four molecular targets by > 50% (p < 0.05 vs. non-treated at day 3 and 21). On aortic root histology, mice undergoing MI versus controls had 2-4 fold greater plaque size and macrophage content (p < 0.05), approximately 20-fold greater platelet adhesion (p < 0.05), and increased staining for markers of platelet transforming growth factor-ß1 signaling. Accelerated plaque growth and inflammatory activation was almost entirely prevented by ADAMTS13 and NAC. Inhibition of FXI had no significant effect on molecular imaging signal or plaque morphology. CONCLUSIONS: Plaque inflammatory activation in remote arteries after MI is strongly influenced by VWF-mediated platelet adhesion to the endothelium. These findings support investigation into new secondary preventive therapies for reducing non-culprit artery events after MI.


Assuntos
Proteína ADAMTS13 , Infarto do Miocárdio , Fator de von Willebrand , Animais , Fator de von Willebrand/metabolismo , Infarto do Miocárdio/patologia , Infarto do Miocárdio/complicações , Proteína ADAMTS13/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo , Camundongos , Placa Aterosclerótica/patologia , Selectina-P/metabolismo , Células Endoteliais/metabolismo , Células Endoteliais/efeitos dos fármacos , Masculino , Imagem Molecular , Aorta/patologia , Aorta/efeitos dos fármacos , Acetilcisteína/farmacologia , Acetilcisteína/uso terapêutico , Camundongos Endogâmicos C57BL
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