ABSTRACT
BACKGROUND: The promotion of physical activity and the decrease of inactivity and sedentary behaviour are crucial for a healthy lifestyle and positive quality of life. People with intellectual disabilities are at increased risk of inactivity and sedentary behaviour. Therefore, it is important to increase their physical activity by implementing physical activity guidelines in their daily life. Professional direct care providers can play a decisive role in supporting people with intellectual disabilities to participate in physical activity, but the engagement of direct care providers with this role may be reflective of their own attitudes and beliefs towards physical activity. Therefore, the link between the implementation of current physical activity guidelines for people with intellectual disabilities and direct care providers' own beliefs and behaviour with regard to physical activity is investigated. METHOD: A total of 104 direct care providers completed self-reported questionnaires about their own physical activity behaviour (IPAQ-SF), recommendations for people with intellectual disabilities (adaption of EMIQ-HP) and questions regarding global physical activity guidelines. They were also asked about potential barriers and facilitators for the recommendation of physical activity in open-ended questions. RESULTS: Personal physical activity behaviour is related to the recommended physical activity for people with intellectual disabilities (moderate-to-vigorous physical activity: rs = 0.408, P = 0.005). However, recommended physical activity behaviour for people with intellectual disabilities is significantly lower than direct care providers' own physical activity behaviour (P < 0.001). 47.1% of the respondents recommended people with intellectual disabilities to participate in less than the 150 min of moderate intensity physical activity per week for that is recommended in global physical activity guidelines. CONCLUSION: Direct care providers may hold stereotypical views and insecurities about the potential harms associated with people with intellectual disabilities participating in physical activity. Therefore, the dissemination of physical activity recommendations for people with intellectual disabilities should be a major target for health professionals, social workers and scientists to address direct care providers' concerns. Furthermore, we need to emphasise the benefits of regular physical activity to professional direct care providers and directly to people with intellectual disabilities.
Subject(s)
Intellectual Disability , Humans , Quality of Life , Exercise , Sedentary Behavior , Motor ActivityABSTRACT
BACKGROUND: Combining the strengths of physical activity (PA) diaries and questionnaires may be needed to improve the unsatisfying measurement quality of existing PA questionnaires. This study investigated the construct validity of a short PA questionnaire (Physical Activity Questionnaire for 24 h [PAQ24]) with a recall period of one day. METHODS: In this cross-sectional study, participants completed the PAQ24 on seven consecutive days while wearing an accelerometer (GENEActiv). Thereafter, the Global Physical Activity Questionnaire (GPAQ) was completed. Spearman correlation coefficients and Bland-Altman analysis were used to assess construct validity. RESULTS: Overall, 50 active adults (11 women, mean age = 25.1 ± 2.5) participated. Relative agreements between Total PA of PAQ24 and accelerometer were 0.37 ≤ ρ ≤ 0.72 for each day with satisfying agreement on five out of seven days. Weekly relative agreement for Total PA was moderate (ρ = 0.44). Relative agreements between PAQ24 and GPAQ were ρ = 0.43 for Total PA. Daily and weekly absolute agreements were poor indicated by wide limits of agreement. CONCLUSIONS: In contrast to weekly Total PA, the majority of daily results of the PAQ24 showed satisfying construct validity. A short recall period may improve the measurement quality of PA questionnaires, but measurement errors and the costs of multiple administrations must be considered in future studies.
Subject(s)
Exercise , Mental Recall , Surveys and Questionnaires , Adult , Cross-Sectional Studies , Female , Humans , Male , Reproducibility of Results , Time Factors , Young AdultABSTRACT
The tissue factor (TF) pathway plays a central role in hemostasis and thrombo-inflammatory diseases. Although structure-function relationships of the TF initiation complex are elucidated, new facets of the dynamic regulation of TF's activities in cells continue to emerge. Cellular pathways that render TF non-coagulant participate in signaling of distinct TF complexes with associated proteases through the protease-activated receptor (PAR) family of G protein-coupled receptors. Additional co-receptors, including the endothelial protein C receptor (EPCR) and integrins, confer signaling specificity by directing subcellular localization and trafficking. We here review how TF is switched between its role in coagulation and cell signaling through thiol-disulfide exchange reactions in the context of physiologically relevant lipid microdomains. Inflammatory mediators, including reactive oxygen species, activators of the inflammasome, and the complement cascade play pivotal roles in TF procoagulant activation on monocytes, macrophages and endothelial cells. We furthermore discuss how TF, intracellular ligands, co-receptors and associated proteases are integrated in PAR-dependent cell signaling pathways controlling innate immunity, cancer and metabolic inflammation. Knowledge of the precise interactions of TF in coagulation and cell signaling is important for understanding effects of new anticoagulants beyond thrombosis and identification of new applications of these drugs for potential additional therapeutic benefits.
Subject(s)
Blood Coagulation , Signal Transduction , Thromboplastin/metabolism , Animals , Endothelial Cells/metabolism , Factor VIIa/metabolism , Factor Xa/metabolism , Humans , Inflammation/blood , Myeloid Cells/metabolism , Neoplasms/blood , Receptor, PAR-2/blood , Thrombosis/bloodABSTRACT
Atherothrombosis is a leading cause of cardiovascular mortality and long-term morbidity. Platelets and coagulation proteases, interacting with circulating cells and in different vascular beds, modify several complex pathologies including atherosclerosis. In the second Maastricht Consensus Conference on Thrombosis, this theme was addressed by diverse scientists from bench to bedside. All presentations were discussed with audience members and the results of these discussions were incorporated in the final document that presents a state-of-the-art reflection of expert opinions and consensus recommendations regarding the following five topics: 1. Risk factors, biomarkers and plaque instability: In atherothrombosis research, more focus on the contribution of specific risk factors like ectopic fat needs to be considered; definitions of atherothrombosis are important distinguishing different phases of disease, including plaque (in)stability; proteomic and metabolomics data are to be added to genetic information. 2. Circulating cells including platelets and atherothrombosis: Mechanisms of leukocyte and macrophage plasticity, migration, and transformation in murine atherosclerosis need to be considered; disease mechanism-based biomarkers need to be identified; experimental systems are needed that incorporate whole-blood flow to understand how red blood cells influence thrombus formation and stability; knowledge on platelet heterogeneity and priming conditions needs to be translated toward the in vivo situation. 3. Coagulation proteases, fibrin(ogen) and thrombus formation: The role of factor (F) XI in thrombosis including the lower margins of this factor related to safe and effective antithrombotic therapy needs to be established; FXI is a key regulator in linking platelets, thrombin generation, and inflammatory mechanisms in a renin-angiotensin dependent manner; however, the impact on thrombin-dependent PAR signaling needs further study; the fundamental mechanisms in FXIII biology and biochemistry and its impact on thrombus biophysical characteristics need to be explored; the interactions of red cells and fibrin formation and its consequences for thrombus formation and lysis need to be addressed. Platelet-fibrin interactions are pivotal determinants of clot formation and stability with potential therapeutic consequences. 4. Preventive and acute treatment of atherothrombosis and arterial embolism; novel ways and tailoring? The role of protease-activated receptor (PAR)-4 vis à vis PAR-1 as target for antithrombotic therapy merits study; ongoing trials on platelet function test-based antiplatelet therapy adjustment support development of practically feasible tests; risk scores for patients with atrial fibrillation need refinement, taking new biomarkers including coagulation into account; risk scores that consider organ system differences in bleeding may have added value; all forms of oral anticoagulant treatment require better organization, including education and emergency access; laboratory testing still needs rapidly available sensitive tests with short turnaround time. 5. Pleiotropy of coagulation proteases, thrombus resolution and ischaemia-reperfusion: Biobanks specifically for thrombus storage and analysis are needed; further studies on novel modified activated protein C-based agents are required including its cytoprotective properties; new avenues for optimizing treatment of patients with ischaemic stroke are needed, also including novel agents that modify fibrinolytic activity (aimed at plasminogen activator inhibitor-1 and thrombin activatable fibrinolysis inhibitor.
Subject(s)
Thromboembolism/therapy , Thrombosis/blood , Thrombosis/therapy , Anticoagulants/therapeutic use , Biomarkers/blood , Blood Coagulation , Erythrocytes/metabolism , Factor VIII/metabolism , Factor XII/metabolism , Factor XIII/metabolism , Humans , Macrophages/metabolism , Netherlands , Phenotype , Plaque, Atherosclerotic/blood , Plaque, Atherosclerotic/diagnosis , Plaque, Atherosclerotic/therapy , Polyphosphates/metabolism , Risk Factors , Signal Transduction , Thromboembolism/blood , Thromboembolism/diagnosis , Thrombosis/diagnosisABSTRACT
INTRODUCTION: Tissue Factor (TF) promotes apoptosis-resistance and facilitates haematogenous metastasis. Cancer cells release TF-bearing microparticles (TF-MP) which have pro-coagulant activity. TF-MPs from cancer cells induce increase in TF expression and procoagulant activity of recipient endothelial cells. Drug resistance microparticles transfer between cancer cells, resulting in induction of recipient cell drug resistance, however transfer of TF-MPs between cancer cells has not been demonstrated. AIM: To determine if microparticles isolated from TF expressing cancer cell lines can induced TF-mediated procoagulant activity in cell lines that do not express TF. MATERIALS AND METHODS: A7 cells (a melanoma cell line that does not express TF) were transformed to express TF with adenoviral transformation. In addition, the TF-expressing breast cancer cell line MDAMB231 was used. Media was collected from (1) wild-type A7 (A7-WT) cells, which acted as control (2) MDAMB231 cells, (3) A7 cells transformed with 'low' levels of TF-adenovirus and (4) A7 cells transformed with 'high' levels of TF-adenovirus. MPs were isolated from media by centrifugation using standard techniques. Isolated MPs were incubated with wild-type A7 (A7-WT) cells overnight. Pro-coagulant activity of A7-WT cells was assessed using a FXa generation assay. RESULTS: i) A7-WT cells incubated overnight with MDAMB231-derived MPs produced an almost 5 fold increase in procoagulant activity compared to control (Mean 3.5 mOD/min S.E 0.32 vs control 0.68 S.E. 0.05, p<0.01). ii) MPs released from A7-TF cells induced a dose-dependant increase in cell based procoagulant activity when incubated with A7-WTs compared to control:A7-WT cells incubated with control MPs (Control): mean mOD 0.83, S.E. 0.07A7-WT cells incubated with A7-TF derived MPs (low levels of TF-adenovirus): mean mOD 1.27, S.E. 0.06 (p=0.04 vs control)A7-WT cells incubated with A7-TF derived MPs (low levels of TF-adenovirus): mean mOD 2.77, S.E. 0.23 (p<0.01 vs control). CONCLUSIONS: These results demonstrate, for the first time, microparticle-mediated transfer of TF procoagulant activity between cancer cells. MPs shed by cancer cells in vivo have been implicated in cancer cell progression and hypercoagulability. The acquisition and spread of of MP-mediated TF activity has implications for cancer cell biology and cancer-induced hypercoagulability.
ABSTRACT
BACKGROUND: Until now, nonivamide/nicoboxil ointment has not been tested in a randomized trial for the treatment of acute non-specific low back pain. METHODS: This phase III randomized, double-blind, active- and placebo-controlled, multi-centre trial investigated efficacy, safety and tolerability of topical nicoboxil 2.5%/nonivamide 0.4% for treatment of acute non-specific low back pain [primary endpoint: pain intensity (PI) difference between pre-dose baseline and 8 h after the first application]. RESULTS: Patients (n = 805), 18-74 years of age were treated for up to 4 days with nicoboxil 2.5%/nonivamide 0.4%, nicoboxil 2.5%, nonivamide 0.4% or placebo ointment. Pre-dose baseline pain intensity (6.6 on a 0- to 10-point numerical rating scale) was reduced by 1.049 points with placebo, by 1.428 points with nicoboxil, by 2.252 points with nonivamide and by 2.410 points with nicoboxil/nonivamide after 8 h (p < 0.0001 for nicoboxil/nonivamide vs. placebo, nicoboxil; p = 0.4171 for nicoboxil/nonivamide vs. nonivamide). At the end of treatment, the combination provided more pronounced PI reduction (3.540 points) compared with nicoboxil (2.371, p < 0.0001), nonivamide (3.074, p = 0.0259) and placebo (1.884, p < 0.0001). Low back mobility scores on Day 1 were better for the combination compared with all other treatments (p < 0.044); on Day 2-4, scores were better than for placebo and nicoboxil (p < 0.003). Patients assessed efficacy of the combination as greater than of the comparators (p ≤ 0.0129). All treatments were tolerated well. No treatment-related serious adverse events were reported. CONCLUSION: Nicoboxil/nonivamide ointment is an effective, well-tolerated medication for the treatment of acute non-specific low back pain.
Subject(s)
Acute Pain/drug therapy , Capsaicin/analogs & derivatives , Low Back Pain/drug therapy , Nicotinic Acids/therapeutic use , Adolescent , Adult , Aged , Capsaicin/adverse effects , Capsaicin/therapeutic use , Double-Blind Method , Drug Combinations , Female , Humans , Male , Middle Aged , Nicotinic Acids/adverse effects , Treatment Outcome , Young AdultABSTRACT
Obesity is a major cause for a spectrum of metabolic syndrome-related diseases that include insulin resistance, type 2 diabetes, and steatosis of the liver. Inflammation elicited by macrophages and other immune cells contributes to the metabolic abnormalities in obesity. In addition, coagulation activation following tissue factor (TF) upregulation in adipose tissue is frequently found in obese patients and particularly associated with diabetic complications. Genetic and pharmacological evidence indicates that TF makes significant contributions to the development of the metabolic syndrome by signaling through G protein-coupled protease activated receptors (PARs). Adipocyte TF-PAR2 signaling contributes to diet-induced obesity by decreasing metabolism and energy expenditure, whereas hematopoietic TF-PAR2 signaling is a major cause for adipose tissue inflammation, hepatic steatosis and inflammation, as well as insulin resistance. In the liver of mice on a high fat diet, PAR2 signaling increases transcripts of key regulators of gluconeogenesis, lipogenesis and inflammatory cytokines. Increased markers of hepatic gluconeogenesis correlate with decreased activation of AMP-activated protein kinase (AMPK), a known regulator of these pathways and a target for PAR2 signaling. Clinical markers of a TF-induced prothrombotic state may thus indicate a risk in obese patient for developing complications of the metabolic syndrome.
Subject(s)
Inflammation/immunology , Metabolic Syndrome/immunology , Obesity/immunology , Receptor, PAR-2/immunology , Signal Transduction/immunology , Thromboplastin/immunology , Animals , Humans , Immunologic Factors/immunology , Models, ImmunologicalABSTRACT
BACKGROUND: Tumor cell tissue factor (TF)-initiated coagulation supports hematogenous metastasis by fibrin formation, platelet activation and monocyte/macrophage recruitment. Recent studies identified host anticoagulant mechanisms as a major impediment to successful hematogenous tumor cell metastasis. OBJECTIVE: Here we address mechanisms that contribute to enhanced metastasis in hyperthrombotic mice with functional thrombomodulin deficiency (TM(Pro) mice). METHODS: Pharmacological and genetic approaches were combined to characterize relevant thrombin targets in a mouse model of experimental hematogenous metastasis. RESULTS: TF-dependent, but contact pathway-independent, syngeneic breast cancer metastasis was associated with marked platelet hyperreactivity and formation of leukocyte-platelet aggregates in immune-competent TM(Pro) mice. Blockade of CD11b or genetic deletion of platelet glycoprotein Ibα excluded contributions of these receptors to enhanced platelet-dependent metastasis in hyperthrombotic mice. Mice with very low levels of the endothelial protein C receptor (EPCR) did not phenocopy the enhanced metastasis seen in TM(Pro) mice. Genetic deletion of the thrombin receptor PAR1 or endothelial thrombin signaling targets alone did not diminish enhanced metastasis in TM(Pro) mice. Combined deficiency of PAR1 on tumor cells and the host reduced metastasis in TM(Pro) mice. CONCLUSIONS: Metastasis in the hyperthrombotic TM(Pro) mouse model is mediated by platelet hyperreactivity and contributions of PAR1 signaling on tumor and host cells.
Subject(s)
Neoplasm Metastasis , Thrombin/metabolism , Thromboplastin/metabolism , Thrombosis/pathology , Animals , Base Sequence , Cell Line, Tumor , DNA Primers , Mice , Mice, Inbred C57BL , Platelet Activation , Polymerase Chain Reaction , Thrombosis/metabolismSubject(s)
Cell Movement/physiology , Thromboplastin/physiology , Animals , Humans , Wnt Proteins/metabolismABSTRACT
BACKGROUND: Tissue factor (TF) is frequently overexpressed in cancer cells and correlated with more aggressive tumor phenotypes and poor prognosis. In addition to promoting coagulation-dependent metastasis and cancer-associated thrombosis, tumor cell-expressed TF mediates direct cell signaling involving the protease-activated receptor (PAR) 2. Ixolaris is a tick-derived inhibitor of the TF-factor (F)VIIa-Xa coagulation initiation complex which blocks primary tumor growth and angiogenesis in glioblastoma and melanoma models. METHODS: In this study we address the anti-tumor effects of Ixolaris in TF-VIIa-PAR2 signaling-dependent breast cancer models, a xenograft model of highly aggressive human MDA-MB-231 mfp cells and a syngeneic model of PAR2-deficient and replete PyMT mouse mammary carcinoma cells. RESULTS: Ixolaris potently inhibited the procoagulant activity of human MDA-MB-231mfp or murine PyMT breast cancer cells. Ixolaris blocked signaling by the ternary TF-FVIIa-FXa complex, and, surprisingly, at higher concentrations also the binary TF-FVIIa complex on MDA-MB-231 cells. We show that Ixolaris interacts with certain residues in the human VIIa protease domain that are involved in PAR2 cleavage. In contrast to human VIIa, Ixolaris was a poor inhibitor of murine TF-FVIIa signaling and did not attenuate PAR2-dependent tumor growth in a syngeneic mouse model of breast cancer progression. CONCLUSION: These data show that Ixolaris inhibits PAR2 cleavage specifically by human TF signaling complexes and suggest that Ixolaris may block tumor growth of human cell models with ectopic FVIIa expression through inhibition of direct TF-FVIIa-PAR2 signaling as well as its anticoagulant activity.
Subject(s)
Salivary Proteins and Peptides/physiology , Signal Transduction/physiology , Thromboplastin/metabolism , Animals , Cell Line, Tumor , Factor VIIa/metabolism , Humans , Mice , Models, MolecularSubject(s)
Antigens, CD/metabolism , Coagulants/administration & dosage , Coagulants/metabolism , Coagulants/pharmacokinetics , Endothelial Cells/enzymology , Factor VIIa/administration & dosage , Factor VIIa/metabolism , Factor VIIa/pharmacokinetics , Factor Xa/metabolism , Receptor, PAR-1/metabolism , Receptors, Cell Surface/metabolism , Signal Transduction , Animals , Humans , MaleABSTRACT
BACKGROUND: TF is highly expressed in cancerous and atherosclerotic lesions. Monocyte recruitment is a hallmark of disease progression in these pathological states. OBJECTIVE: To examine the role of integrin signaling in TF-dependent recruitment of monocytes by endothelial cells. METHODS: The expression of flTF and asTF in cervical cancer and atherosclerotic lesions was examined. Biologic effects of the exposure of primary microvascular endothelial cells (MVEC) to truncated flTF ectodomain (LZ-TF) and recombinant asTF were assessed. RESULTS: flTF and asTF exhibited nearly identical expression patterns in cancer lesions and lipid-rich plaques. Tumor lesions, as well as stromal CD68(+) monocytes/macrophages, expressed both TF forms. Primary MVEC rapidly adhered to asTF and LZ-TF, and this was completely blocked by anti-ß1 integrin antibody. asTF- and LZ-TF-treatment of MVEC promoted adhesion of peripheral blood mononuclear cells (PBMCs) under orbital shear conditions and under laminar flow; asTF-elicited adhesion was more pronounced than that elicited by LZ-TF. Expression profiling and western blotting revealed a broad activation of cell adhesion molecules (CAMs) in MVEC following asTF treatment including E-selectin, ICAM-1 and VCAM-1. In transwell assays, asTF potentiated PMBC migration through MVEC monolayers by â¼3-fold under MCP-1 gradient. CONCLUSIONS: TF splice variants ligate ß1 integrins on MVEC, which induces the expression of CAMs in MVEC and leads to monocyte adhesion and transendothelial migration. asTF appears more potent than flTF in eliciting these effects. Our findings underscore the pathophysiologic significance of non-proteolytic, integrin-mediated signaling by the two naturally occurring TF variants in cancer and atherosclerosis.
Subject(s)
Alternative Splicing , Cell Adhesion Molecules/metabolism , Endothelium, Vascular/cytology , Integrins/metabolism , Monocytes/cytology , Signal Transduction , Thromboplastin/genetics , Blotting, Western , Cells, Cultured , Female , Humans , Reverse Transcriptase Polymerase Chain Reaction , Uterine Cervical Neoplasms/metabolism , Uterine Cervical Neoplasms/pathologyABSTRACT
The close link between coagulation activation and clinical cancer is well established and recent progress has defined underlying molecular pathways by which tumour cells interact with the haemostatic system to promote cancer progression. Tumour type-specific oncogenic transformations cause constitutive and hypoxia-dependent upregulation of tissue factor (TF) in cancer cells, but TF expressed by vascular, stromal and inflammatory cells also contributes to the procoagulant character of the tumour microenvironment. A growing body of genetic and pharmacological evidence implicates signalling by protease activated receptors (PARs) and specifically by tumour cell-expressed TF-VIIa-PAR2 in the induction of an array of proangiogenic and immune modulating cytokines, chemokines and growth factors. Specific inhibition of this pathway results in attenuated tumour growth and angiogenesis. PARs are increasingly recognised as targets for proteases outside the coagulation system and emerging evidence indicates that alternative protease signalling pathways synergise with the coagulation system to promote tumour growth, angiogenesis and metastasis. The elucidation of new therapeutic targets in tumour-promoting protease signalling pathways requires new diagnostic approaches to identify patients that will benefit from tailored therapy targeting procoagulant or signalling aspects of the TF pathway.
Subject(s)
Neoplasms/physiopathology , Thromboplastin/physiology , Thrombosis/physiopathology , Cell Transformation, Neoplastic , Disease Progression , Humans , Models, Molecular , Neoplasms/enzymology , Neoplasms/pathology , Peptide Hydrolases/metabolism , Signal Transduction , Thrombosis/enzymology , Thrombosis/pathologyABSTRACT
BACKGROUND: Thromboembolic events are a major complication in ovarian cancer patients. Tissue factor (TF) is frequently overexpressed in ovarian cancer tissue and correlates with intravascular thrombosis. TF binds to coagulation factor VII (fVII), changing it to its active form, fVIIa. This leads to activation of the extrinsic coagulation cascade. fVII is produced by the liver and believed to be supplied from blood plasma at the site of coagulation. However, we recently showed that ovarian cancer cells express fVII transcripts under normoxia and that this transcription is inducible under hypoxia. These findings led us to hypothesise that ovarian cancer cells are intrinsically associated with TF-fVIIa coagulation activity, which could result in thrombosis. METHODS: In this study, we examined whether ectopically expressed fVII could cause thrombosis by means of immunohistochemistry, RT-PCR, western blotting and flow cytometry. RESULTS: Ectopic fVII expression occurs frequently in ovarian cancers, particularly in clear cell carcinoma. We further showed that ovarian cancer cells express TF-fVIIa on the cell surface under normoxia and that this procoagulant activity is enhanced by hypoxic stimuli. Moreover, we showed that ovarian cancer cells secrete microparticles (MPs) with TF-fVIIa activity. Production of this procoagulant secretion is enhanced under hypoxia. CONCLUSION: These results raise the possibility that cancer cell-derived TF-fVIIa could cause thrombotic events in ovarian cancer patients.
Subject(s)
Factor VII/metabolism , Ovarian Neoplasms/metabolism , Thromboplastin/metabolism , Venous Thromboembolism/etiology , Cell Hypoxia , Cell Line, Tumor , Cell-Derived Microparticles/metabolism , Female , Humans , Neoplasms, Glandular and Epithelial/chemistry , Ovarian Neoplasms/complications , Ovarian Neoplasms/pathologyABSTRACT
The initiator of coagulation, full-length tissue factor (flTF), in complex with factor VIIa, influences angiogenesis through PAR-2. Recently, an alternatively spliced variant of TF (asTF) was discovered, in which part of the TF extracellular domain, the transmembrane, and cytoplasmic domains are replaced by a unique C terminus. Subcutaneous tumors produced by asTF-secreting cells revealed increased angiogenesis, but it remained unclear if and how angiogenesis is regulated by asTF. Here, we show that asTF enhances angiogenesis in matrigel plugs in mice, whereas a soluble form of flTF only modestly enhances angiogenesis. asTF dose-dependently upregulates angiogenesis ex vivo independent of either PAR-2 or VIIa. Rather, asTF was found to ligate integrins, resulting in downstream signaling. asTF-alphaVbeta3 integrin interaction induces endothelial cell migration, whereas asTF-dependent formation of capillaries in vitro is dependent on alpha6beta1 integrin. Finally, asTF-dependent aortic sprouting is sensitive to beta1 and beta3 integrin blockade and a TF-antibody that disrupts asTF-integrin interaction. We conclude that asTF, unlike flTF, does not affect angiogenesis via PAR-dependent pathways but relies on integrin ligation. These findings indicate that asTF may serve as a target to prevent pathological angiogenesis.
Subject(s)
Alternative Splicing , Integrin alpha6beta1/metabolism , Integrin alphaVbeta3/metabolism , Neovascularization, Pathologic/genetics , Thromboplastin/genetics , Animals , Aorta/growth & development , Aorta/metabolism , Capillaries/growth & development , Capillaries/metabolism , Cell Movement , Endothelium, Vascular/metabolism , Factor V/metabolism , Mice , Mice, Inbred C57BL , Receptor, PAR-2/metabolismABSTRACT
The intrinsic signaling networks of the coagulation pathways have recently emerged as crucial determinants for survival in sepsis and systemic inflammatory response syndromes. Protease activated receptor (PAR) 1 is central to both lethality promoting and vascular protective signaling. In the vascular anticoagulant pathway, EPCR/aPC-PAR1 signaling prevents vascular leakage and genetic or acute deficiencies in this pathway promote lethality. In addition, coagulation signaling acts directly on cells of the innate immune system. Dendritic cell (DC) thrombin-PAR1 signaling is coupled to the migration promoting sphingosine 1 phosphate receptor 3 (S1P3). Thrombin generated in the lymphatic compartment perturbs DCs to promote systemic inflammation and disseminated intravascular coagulation in severe sepsis. Signaling-selective aPC variants and selective modulators of the S1P receptor system attenuate sepsis lethality, suggesting novel therapeutic approaches that can be employed to rebalance alterations in the coagulation signaling pathways in severe inflammatory disorders.
Subject(s)
Blood Coagulation , Sepsis/pathology , Dendritic Cells/pathology , Endothelium, Vascular/pathology , Humans , Sepsis/physiopathology , Signal TransductionABSTRACT
BACKGROUND: Tissue factor (TF) and factor (F) VIIa are the primary initiators of the coagulation cascade, but also promote non-hemostatic events, such as angiogenesis and tumor growth, via activation of protease activated receptor-2 (PAR2). Our previous findings indicated that the TF:FVIIa complex activates signal transducer and activator of transcription (STAT) signaling, leading to cell survival in TF-transfected baby hamster kidney (BHK) cells. METHODS: Using BHK TF, keratinocytes (HaCaT) and human umbilical vein endothelial cells (HUVEC), FVIIa-induced phosphorylation and activation of the transcription factor cyclic AMP-responsive binding protein (CREB) were tested and compared to that elicited by thrombin and FXa. In addition, the effect of these factors on cell survival and expression of apoptosis-associated proteins was monitored. RESULTS: Factor VIIa led to a TF-dependent, but TF cytoplasmic domain-independent phosphorylation and activation of CREB in BHK TF, HaCaT and HUVEC. CREB activation was sensitive to blockade of the extracellular-signal regulated kinase 1/2 pathway and PAR2. Surprisingly, FVIIa decreased cell survival in HaCaT cells but not other cell types and upregulated the pro-apoptotic proteins Bak and Puma in a CREB-dependent manner. Factor Xa, but not FIIa, induced phosphorylation of CREB, but did not have an effect on apoptosis. CONCLUSION: TF:FVIIa induces CREB phosphorylation and activation in several cell types, but TF:FVIIa induces pro-apoptotic proteins and apoptosis only in selected cell types.