thromboplastin and Obesity

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.

Topics: Animals; Humans; Immunologic Factors; Inflammation; Metabolic Syndrome; Models, Immunological; Obesity; Receptor, PAR-2; Signal Transduction; Thromboplastin

Clinical and epidemiological studies support a connection between obesity and thrombosis, involving elevated expression of the prothrombotic molecules plasminogen activator inhibitor-1 and tissue factor (TF) and increased platelet activation. Cardiovascular diseases and metabolic syndrome-associated disorders, including obesity, insulin resistance, type 2 diabetes, and hepatic steatosis, involve inflammation elicited by infiltration and activation of immune cells, particularly macrophages, into adipose tissue. Although TF has been clearly linked to a procoagulant state in obesity, emerging genetic and pharmacologic evidence indicate that TF signaling via G protein-coupled protease-activated receptors (PAR2, PAR1) additionally drives multiple aspects of the metabolic syndrome. TF-PAR2 signaling in adipocytes contributes to diet-induced obesity by decreasing metabolism and energy expenditure, whereas TF-PAR2 signaling in hematopoietic and myeloid cells drives adipose tissue inflammation, hepatic steatosis, and insulin resistance. TF-initiated coagulation leading to thrombin-PAR1 signaling also contributes to diet-induced hepatic steatosis and inflammation in certain models. Thus, in obese patients, clinical markers of a prothrombotic state may indicate a risk for the development of complications of the metabolic syndrome. Furthermore, TF-induced signaling could provide new therapeutic targets for drug development at the intersection between obesity, inflammation, and thrombosis.

Topics: Adipocytes; Adipose Tissue; Animals; Cardiovascular Diseases; Gene Expression Regulation; Humans; Inflammation; Insulin Resistance; Macrophages; Metabolic Syndrome; Mice; Mice, Obese; Models, Biological; Obesity; Plasminogen Activator Inhibitor 1; Receptor, PAR-1; Receptor, PAR-2; Risk Factors; Signal Transduction; T-Lymphocytes, Regulatory; Thrombophilia; Thromboplastin; Thrombosis

The prevalence of obesity has dramatically increased during the past two decades. Epidemiological studies suggest that obesity is an independent, modifiable risk factor for coronary heart disease, possibly due, at least in part, to the development of a pro-inflammatory and a pro-thrombotic state in obese subjects. In addition, numerous cohort studies have shown a link between obesity and different types of cancer. Accordingly, the regulation of body weight is becoming a serious concern for public health experts and scientists. Although the mechanisms responsible for these associations are still to be fully elucidated, a key role has been assigned to adipokines, a family of hormones which act as modulators of metabolism or inflammation, secreted by adipocytes. Tissue factor, the major physiological trigger of the blood coagulation cascade in vivo, which plays a central role in atherothrombosis and tumor biology, has also been proposed as one of the key molecules responsible for these associations.

Topics: Adipokines; Adipose Tissue; Animals; Atherosclerosis; Blood Coagulation; Humans; Inflammation Mediators; Neoplasms; Obesity; Risk Factors; Signal Transduction; Thromboplastin; Thrombosis

1. Obesity is a major risk factor for cardiovascular disease. An increased body mass index (BMI) is associated with venous thromboembolism, myocardial infarction, stroke and stent thrombosis after percutaneous interventions. Studies in mouse models of obesity and induced arterial or venous thrombosis have provided insights into the mechanisms involved. 2. In addition to elevated circulating levels of fibrinogen, factor VII and plasminogen activator inhibitor (PAI)-1, changes in platelet biology and function may underlie the increased (athero) thrombotic risk in obesity. These include elevated platelet counts, an increase in mean platelet volume, an increased platelet aggregatory response to agonists and a reversible resistance to the anti-aggregatory effects of nitric oxide and prostacyclin I(2) . 3. Specific adipokines mediate the prothrombotic state in obesity. Of these, leptin enhances both arterial and venous thrombosis by promoting platelet adhesion, activation and aggregation. Leptin also induces tissue factor expression by human neutrophils and other cells. C-Reactive protein enhances the formation of monocyte-platelet aggregates and also promotes P-selectin expression and platelet adhesion to endothelial cells. Further, the adipose tissue is a significant source of tissue factor and PAI-1. Conversely, the circulating levels of adiponectin, a hormone that exerts vasculoprotective, anti-atherosclerotic and antithrombotic effects, are reduced in obese individuals. 4. A better understanding of the interactions of the adipose tissue with circulating and vascular cells and the dissection of the mechanisms linking adipokines to arterial and venous thrombosis may identify obese individuals at particularly high cardiovascular risk and indicate promising vasculoprotective and therapeutic targets.

Topics: Adipokines; Adipose Tissue; Animals; Blood Platelets; Body Mass Index; C-Reactive Protein; Cardiovascular Diseases; Epoprostenol; Female; Humans; Male; Mice; Neutrophils; Nitric Oxide; Obesity; P-Selectin; Platelet Adhesiveness; Platelet Aggregation Inhibitors; Thromboplastin; Thrombosis

Venous thromboembolism (VTE) is a known complication of cancer which impacts on patient mortality and quality of life. Despite the known deleterious effects of VTE, the benefits of thromboprophylaxis have not been fully established. Identification of patients at highest risk of VTE could lead to better targeting of thromboprophylaxis. Several risk factors have been identified as contributing to VTE such as site and stage of cancer, age, comorbidities, obesity, and acquired prothrombotic states. Anti-cancer agents as well as the use of growth factor support have also been implicated in VTE. Recent data have identified biomarkers such as blood counts, tissue factor and P-selectin. In this review, we briefly summarize the risk factors for VTE as well as candidate biomarkers for VTE in cancer patients. We also review a validated risk score that can identify cancer patients at high risk for VTE. Risk stratification of cancer patients will allow clinicians to identify those patients at highest risk for VTE, who may derive the most benefit from thromboprophylaxis.

Topics: Aged; Factor V; Female; Humans; Infections; Leukocyte Count; Male; Neoplasms; Obesity; P-Selectin; Platelet Count; Risk Factors; Thromboplastin; Venous Thromboembolism

Atherothrombotic vascular disease is a complex disorder in which inflammation and coagulation play a pivotal role. Rupture of high-risk, vulnerable plaques with the subsequent tissue factor (TF) exposure is responsible for coronary thrombosis, the main cause of unstable angina, acute myocardial infarction, and sudden cardiac death. Tissue factor (TF), the key initiator of coagulation is an important modulator of inflammation. TF is widely expressed in atherosclerotic plaques and found in macrophages, smooth muscle cells, extracellular matrix and acellular lipid-rich core. TF expression can be induced by various stimulants such as C-reactive protein, oxLDL, hyperglycemia and adipocytokines. The blood-born TF encrypted on the circulating microparticles derived from vascular cells is a marker of vascular injury and a source of procoagulant activity. Another form of TF, called alternatively spliced has been recently identified in human and murine. It is soluble, circulates in plasma and initiates coagulation and thrombus propagation. Evidence indicates that elevated levels of blood-borne or circulating TF has been associated with metabolic syndrome, type 2 diabetes and cardiovascular risk factors and is a candidate biomarker for future cardiovascular events. Therapeutic strategies have been developed to specifically interfere with TF activity in the treatment of cardiovascular disease.

Topics: Coronary Artery Disease; Coronary Thrombosis; Diabetes Mellitus; Endothelium, Vascular; Humans; Hyperglycemia; Inflammation; Obesity; Thromboplastin

Topics: Adipocytes; Animals; Cardiovascular Diseases; Fatty Acids, Nonesterified; Gene Expression Regulation; Humans; Insulin; Obesity; Plasminogen Activator Inhibitor 1; RNA, Messenger; Serine Proteinase Inhibitors; Thromboplastin; Thrombosis; Transforming Growth Factor beta; Triglycerides; Tumor Necrosis Factor-alpha

Topics: Arthritis; Blood Coagulation Factors; Collagen Diseases; Diabetes Complications; Endocrine Glands; Glucocorticoids; Humans; Myeloproliferative Disorders; Obesity; Sex Factors; Thromboembolism; Thrombophlebitis; Thromboplastin; Thyroid Diseases

Increased coagulation activation may contribute to the high incidence of cardiovascular complications observed in obese and type 2 diabetes (T2D) subjects. Although tissue factor (TF), the primary initiator of coagulation is increased in obesity, its expression in adipose tissues and its association with metabolic parameters are unclear. We sought to compare TF expression in plasma and adipose tissues of obese subjects with and without T2D, its correlation with metabolic parameters, and regulation in response to antidiabetic drugs.. Subjects were recruited from diabetes clinics and adipose tissue was obtained by needle biopsy of lower subcutaneous abdominal depot. For the intervention study, subjects were randomized into treatment groups with rosiglitazone or metformin for 4 months.. Plasma TF antigen, activity, and adipose TF mRNA were greater in obese T2D subjects compared with obese nondiabetics. Plasma TF activity correlated with fasting insulin, glucose, and free fatty acids, (FFAs), and adipose TF mRNA correlated with plasma FFA. Plasma TF activity was reduced by metformin and increased with rosiglitazone treatment.. Specific diabetes-related metabolic parameters, but not obesity per se, are correlated with TF expression. Regulation of TF activity by different classes of antidiabetic drugs may relate to protective or adverse cardiovascular outcomes.

Topics: Adult; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; Gene Expression Regulation; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Obesity; Rosiglitazone; Thiazolidinediones; Thromboplastin

In obesity, metabolic stress and inflammation in injured tissues could favour enhanced shedding of procoagulant microparticles (MPs). At sites of endothelium injury, the swift recruitment of procoagulant leukocyte-derived MPs enables the initiation of blood coagulation and thrombus growth.. In obese females, we sought to evaluate the impact of a very low-calorie diet (VLCD) on procoagulant MP levels, fibrinolytic status, inflammation and endothelium damage.. Circulating biomarkers of vascular damage, fibrinolytic status, platelet activation and inflammation were measured before, 30 and 90 days after starting a short-term VLCD. MPs were measured by flow cytometry and capture assays. Their procoagulant potential was quantified using functional prothrombinase assays and their cellular origin were determined using flow cytometry (endothelium, platelet, leukocyte, lymphocyte and erythrocyte-derived MP) or capture assays.. A total of 24 obese females (39 ± 10 years) with a mean body mass index of 35 ± 4  kg m(-2) were prospectively enroled. Procoagulant leukocyte-derived MPs were associated with the waist circumference at baseline (r=0.534; P=0.010) and at 90 days follow-up (r=0.487; P=0.021). At 90 days, weight reduction (-9.8%) was associated with a lowering of blood pressure, improvement of metabolic parameters and a significant reduction of plasminogen activator inhibitor-1 (PAI-1) (-38%), procoagulant platelet-derived MPs (-43%), leukocyte-derived MPs (-28%) and leptin (-32%) levels.. In obese females, a short-term VLCD results in an overall improvement of the haemostatic balance characterized by the reduction of PAI-levels, diminished release of platelet and leukocyte-derived MPs and a reduction in leptin levels, an adipocyte-derived cytokine.

Topics: Adolescent; Adult; Aged; Biomarkers; Blood Coagulation Factors; Blood Platelets; Caloric Restriction; Endothelium, Vascular; Erythrocytes; Female; Hemostasis; Humans; Leptin; Leukocytes; Middle Aged; Obesity; Plasminogen Activator Inhibitor 1; Prospective Studies; Thromboplastin; Thrombosis; Weight Loss; Young Adult

Thrombotic events are highly prevalent in coronavirus disease 2019 (COVID-19), especially in patients presenting with risk factors of adverse outcomes such as obesity. Recently, the associations between the angiotensin converting enzyme 2 (ACE2) pathway and thrombosis have been reported. Angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARBs) are widely used cardiovascular pharmacologic agents that upregulate ACE2 levels. An observation of the alterations in pro-coagulation factors after exposure to ACEIs and ARBs may provide valuable insight into the thrombosis mechanism and how it may relate to ACE2. This study use adipose tissue harvested from an obese male donor was isolated and exposed to perindopril, losartan, and ACE2 recombinant as binding assay, following exposure with 10 nm of SARS-CoV-2 S1 spike protein. After 48 hours, tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) as pro-coagulation factors as well as ACE2 levels and binding evaluated. The results shows TF level was significantly reduced in Perindopril group compared to control (4.834; p=0.005), while a non-significant reduction was observed in Losartan group (5.624; p=0.111). However, Losartan group showed a better reduction of PAI-1 levels (2.633; p≤0.001) than Perindopril group (3.484; p=0.001). These findings were consistent with the observations in ACE2 recombinant group, suggesting that both drugs lowered the bindings of ACE2 and SARS-CoV-2 spike proteins. This study indicated that both perindopril and losartan may attenuate pro-coagulation factors in human adipocytes exposed to SARS-CoV-2 spike proteins, and therefore showcased a potential role of ACE2 in the mechanism of COVID-19-related thrombosis. Further investigation in non-COVID-19 populations should commence and may be of value to expanding this potential in general cardiovascular diseases.

Topics: Adipocytes; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme 2; Angiotensin-Converting Enzyme Inhibitors; Blood Coagulation Factors; Cardiovascular Agents; COVID-19; Humans; Losartan; Male; Obesity; Perindopril; Plasminogen Activator Inhibitor 1; SARS-CoV-2; Spike Glycoprotein, Coronavirus; Thromboplastin

Obesity has reached epidemic proportions and is a well-recognised risk factor for venous thromboembolism (VTE). This article summarises the current understanding of obesity and debates how obesity induces this increased risk of VTE. Obesity is associated with prothrombotic changes which have been well-characterised and include increased levels of plasminogen activator-1, von Willebrand factor, fibrinogen and evidence of increased coagulation and platelet activation; however, these changes do not seem to account for all the increased risk. Accumulating evidence suggests a significant role for increased tissue factor expression and signalling in this relationship, with increased tissue factor expression present in adipose and possibly systemic tissues, induced by adipose generated cytokines. Lastly, there is a strong suggestion that decreased venous flow due to venous enlargement may play the major role in increased VTE risk with obesity.

Topics: Body Mass Index; Female; Hemostasis; Humans; Obesity; Pregnancy; Pregnancy Complications, Cardiovascular; Thromboplastin; Veins; Venous Thromboembolism; Women's Health

This study investigated the effects of a flavonoid-rich ethanol extract of persimmon leaf (PL), an ethanol extract of Citrus junos Sieb (CJS), and a PL-CJS mixture (MPC) on mice fed a highfat diet (HFD). We sought to elucidate the mechanisms of biological activity of these substances using measurements of blood coagulation indices and lipid metabolism parameters. C57BL/6J mice were fed a HFD with PL (0.5% (w/w)), CJS (0.1% (w/w)), or MPC (PL 0.5%, CJS 0.1% (w/w)) for 10 weeks. In comparison with data obtained for mice in the untreated HFD group, consumption of MPC remarkably prolonged the activated partial thromboplastin time (aPTT) and prothrombin time (PT), whereas exposure to PL prolonged aPTT only. Lower levels of plasma total cholesterol, hepatic cholesterol, and erythrocyte thiobarbituric acid-reactive substances, hepatic HMG-CoA reductase, and decreased SREBP-1c gene expression were observed in mice that received PL and MPC supplements compared with the respective values detected in the untreated HFD animals. Our results indicate that PL and MPC may have beneficial effects on blood circulation and lipid metabolism in obese mice.

Topics: Animals; Anticholesteremic Agents; Blood Coagulation; Cholesterol; Citrus; Diet, High-Fat; Diospyros; Ethanol; Hydroxymethylglutaryl CoA Reductases; Lipid Metabolism; Liver; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Phytotherapy; Plant Extracts; Plant Leaves; Prothrombin; Sterol Regulatory Element Binding Protein 1; Thromboplastin; Triglycerides

The role of circulating microparticles (MP) of different origin and tissue factor (TF)-bearing in overweight and obese patients with and without metabolic syndrome is still a matter of debate. In a case-control study, the presence of hypercoagulability was evaluated in overweight and obese patients by measuring MP, thrombin generation (TG) and FVIIa-AT complexes. Twenty overweight patients (body mass index [BMI] range 25-29.9 kg/m²), 20 with I degree (30-34.9 kg/m²), 20 with II degree (35-39.9 kg/m²) and 20 with III degree obesity (≥ 40 kg/m²) were enrolled and compared to 40 age and gender-matched normal weight individuals. A significant increase in median levels of all MP subtypes was observed in the three degrees of obese patients compared to controls. Overweight patients had higher levels of annexin V-MP (AMP), endothelial-derived, leukocyte-derived and TF-bearing MP than controls. Obese patients had a significantly shorter median lag time (p< 0.05), higher median peak thrombin (p< 0.01) and increased median endogenous thrombin potential [ETP] (p< 0.001) compared to controls. Overweight subjects had significantly increased ETP compared to controls (p< 0.05). Both AMP levels and ETP were found to positively correlate with BMI, waist circumference, and inflammatory parameters. No significant increase in FVIIa-AT complex was seen in cases compared to controls. We conclude that obesity is associated with overproduction of procoagulant MP and increase TG. Interestingly, hypercoagulability is found in overweight patients free of metabolic syndrome and increases with the severity of obesity. Assessment of MP and TG may be helpful in the early characterisation of the prothrombotic state in obese patients.

Topics: Adult; Antithrombins; Biomarkers; Blood Coagulation; Blood Coagulation Tests; Body Mass Index; Case-Control Studies; Cell-Derived Microparticles; Cross-Sectional Studies; Factor VIIa; Female; Humans; Inflammation Mediators; Male; Middle Aged; Obesity; Overweight; Risk Assessment; Risk Factors; Severity of Illness Index; Thrombin; Thrombophilia; Thromboplastin; Thrombosis; Waist Circumference

Failure to inhibit hepatic gluconeogenesis is a major mechanism contributing to fasting hyperglycemia in type 2 diabetes and, along with steatosis, is the hallmark of hepatic insulin resistance. Obesity is associated with chronic inflammation in multiple tissues, and hepatic inflammation is mechanistically linked to both steatosis and hepatic insulin resistance. Here, we delineate a role for coagulation signaling via tissue factor (TF) and proteinase-activated receptor 2 (PAR2) in obesity-mediated hepatic inflammation, steatosis, and gluconeogenesis. In diet-induced obese mice, TF tail signaling independent of PAR2 drives CD11b(+)CD11c(+) hepatic macrophage recruitment, and TF-PAR2 signaling contributes to the accumulation of hepatic CD8(+) T cells. Transcripts of key pathways of gluconeogenesis, lipogenesis, and inflammatory cytokines were reduced in high-fat diet-fed mice that lack the cytoplasmic domain of TF (F3) (TF(ΔCT)) or that are deficient in PAR2 (F2rl1), as well as by pharmacological inhibition of TF-PAR2 signaling in diet-induced obese mice. These gluconeogenic, lipogenic, and inflammatory pathway transcripts were similarly reduced in response to genetic ablation or pharmacological inhibition of TF-PAR2 signaling in hematopoietic cells and were mechanistically associated with activation of AMP-activated protein kinase (AMPK). These findings indicate that hematopoietic TF-PAR2 signaling plays a pivotal role in the hepatic inflammatory responses, steatosis, and hepatic insulin resistance that lead to systemic insulin resistance and type 2 diabetes in obesity.

Topics: AMP-Activated Protein Kinases; Animals; Diabetes Mellitus, Type 2; Fatty Liver; Gluconeogenesis; Hematopoietic Stem Cells; Hepatitis; Insulin Resistance; Mice; Mice, Knockout; Mice, Obese; Obesity; Receptor, PAR-2; Signal Transduction; Thromboplastin

Obesity is a risk factor for both cardiovascular disease and cancer development. Leptin, a cytokine produced by adipose tissue, controls different processes in peripheral tissues, including cancer development and thrombotic disorders in patients with a variety of clinical disorders. Tissue factor (TF), the trigger of blood clotting, is abundant in the adipose tissue. Since TF, often expressed by cancer cells, is considered a hallmark of cancer progression, we investigated whether leptin could modulate TF in the human metastatic breast carcinoma cell line MCF-7.. MCF-7 cells were incubated with or without the different reagents at 37 °C. At the end of incubation, cells were tested for procoagulant activity by a one-stage clotting assay, TF and TNF-α antigen levels and mRNA by ELISA and real-time RT-PCR, respectively. Leptin receptor was studied by FACS.. Both TF activity and antigen constitutively expressed by MCF-7 were significantly increased by leptin in a dose-dependent fashion. TF mRNA levels were also enhanced indicating that leptin exerts its effect at the transcription level. The effect of leptin was specific and required binding to its receptor (Ob-R), which was found on the surface of the cells, since antibodies against leptin and Ob-R completely prevented TF expression upregulation. In addition, leptin enhanced both TNF-α mRNA synthesis and secretion from MCF7. An anti-TNF-α MoAb completely abolished the leptin-induced TF expression.. These data support the hypothesis that leptin, by its upregulation of TF, possibly mediated by TNF-α synthesis, may contribute to processes underlying both cancer and vascular cell disorders.

Topics: Breast Neoplasms; Cardiovascular Diseases; Cell Line, Tumor; Female; Humans; Leptin; Obesity; Receptors, Leptin; Thromboplastin; Up-Regulation

Childhood obesity is rapidly increasing in prevalence. We compared circulating membrane-bound tissue factor (FIII, F3) procoagulant activity (TF-PCA) and plasma markers of coagulation, fibrinolysis and endothelial dysfunction in 21 obese (10·1 ± 1·5 years, mean ± standard deviation) and 22 healthy weight children (9·9 ± 1·6 years), classified by Body Mass Index (BMI). TF-PCA and factor VII coagulant activity (FVII:C), plasminogen activator inhibitor (PAI-1, SERPINE1) and soluble vascular cell adhesion molecule 1 (sVCAM1) were higher in obese children. BMI correlated positively with TF-PCA, FVII:C, and PAI-1. Childhood obesity is associated with a procoagulant state and endothelial dysfunction. Studies are needed to assess whether weight reduction reverses these abnormalities.

Topics: Biomarkers; Blood Coagulation; Blood Coagulation Factors; Blood Specimen Collection; Body Mass Index; Child; Factor VII; Female; Fibrinolysis; Humans; Male; Obesity; Plasminogen Activator Inhibitor 1; Thromboplastin

Tissue factor, the initiator of the coagulation cascade, mediates coagulation factor VIIa-dependent activation of protease-activated receptor 2 (PAR2). Here we delineate a role for this signaling pathway in obesity and its complications. Mice lacking PAR2 (F2rl1) or the cytoplasmic domain of tissue factor were protected from weight gain and insulin resistance induced by a high-fat diet. In hematopoietic cells, genetic ablation of tissue factor-PAR2 signaling reduced adipose tissue macrophage inflammation, and specific pharmacological inhibition of macrophage tissue factor signaling rapidly ameliorated insulin resistance. In contrast, nonhematopoietic cell tissue factor-VIIa-PAR2 signaling specifically promoted obesity. Mechanistically, adipocyte tissue factor cytoplasmic domain-dependent VIIa signaling suppressed Akt phosphorylation with concordant adverse transcriptional changes of key regulators of obesity and metabolism. Pharmacological blockade of adipocyte tissue factor in vivo reversed these effects of tissue factor-VIIa signaling and rapidly increased energy expenditure. Thus, inhibition of tissue factor signaling is a potential therapeutic avenue for improving impaired metabolism and insulin resistance in obesity.

Topics: Adipose Tissue; Animals; Bone Marrow Transplantation; Diet, High-Fat; Factor VIIa; Glucose; Inflammation; Insulin Resistance; Lipid Metabolism; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Receptor, PAR-2; Signal Transduction; Thromboplastin; Transplantation Chimera

Topics: Adipose Tissue; Animals; Diet, High-Fat; Inflammation; Male; Obesity; Receptor, PAR-2; Signal Transduction; Thromboplastin

1. The relationship between inflammation, obesity-related proteins and tissue factor (TF), the major initiator of the extrinsic clotting cascade, is not well understood. We examined if basal and stimulated peripheral blood mononuclear cell (PBMC) TF-procoagulant activity (PCA) was higher in obese subjects and examined the effects of leptin, resistin and serum amyloid A (SAA). 2. PBMC from 12 obese (six male, aged 29±4years, body mass index 46.0±8.7kg/m(2) ) and 12 age- and sex-matched lean controls were cultured either unstimulated or stimulated by lipopolysaccharide (LPS; 10ρg/mL and 100ng/mL, for 4-16h) or SAA (1 ng/mL, 25ng/mL, 250ng/mL, for 4h). Separately, PBMC from lean subjects were cultured unstimulated with leptin (100ρg/mL, 1ng/mL, 10ng/mL, 100ng/mL, 1 μg/mL), resistin (0.1ng/mL, 1ng/mL, 10ng/mL, 100ng/mL) or leptin (100ng/mL) plus LPS (100ρg/mL). TF-PCA was determined by a 1-stage plasma recalcification assay. 3. Four-hour unstimulated PBMC TF-PCA was greater in the obese (90.4±16.5 vs 39.9±4.7mu TF/10(6) PBMC, P=0.01). After 4h stimulation with SAA or LPS the TF-PCA was similar. Unstimulated TF-PCA correlated with log serum high sensitivity C- reactive protein (hs-CRP) (r=0.42, P=0.04) and insulin (r=0.44, P=0.048), but not with log serum SAA (r=0.192, P=0.55). Physiological concentrations of leptin or resistin and leptin plus LPS did not increase TF-PCA in PBMC from lean subjects. 4. Basal PBMC TF-PCA is higher in the obese and is associated with serum hs-CRP. The obesity-related proteins SAA, leptin and resistin are unlikely to play a major role in increasing PBMC TF-PCA.

Topics: Adult; Case-Control Studies; Cell Culture Techniques; Cells, Cultured; Enzyme-Linked Immunosorbent Assay; Female; Humans; Leptin; Leukocytes, Mononuclear; Lipopolysaccharides; Male; Obesity; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Serum Amyloid A Protein; Thromboplastin; Thrombosis

Leptin is an adipocyte-derived cytokine primarily involved in the regulation of body weight and energy balance. In vivo studies suggest that leptin promotes platelet aggregation and thrombosis. Neutrophils are involved in the crosstalk between inflammation and thrombosis in clinical disorders. Leptin is also involved in the regulation of inflammation.. We examined the in vitro effects of leptin on the expression of tissue factor (TF), the primary initiator of coagulation, in healthy neutrophils.. The effects on TF expression were assayed functionally using a modified prothrombin time (mPT), as well as at mRNA and protein levels. The same experiments were performed in parallel with PBMC. Leptin induced functional TF and increased TF mRNA and protein expression in both cell types, as determined by mPT, real-time RT-PCR, western blot, flow cytometry, immunocytochemistry. Inhibition studies revealed that the effect of leptin on TF expression is mediated, at least in part, by JAK2 and PI3K. Our findings, after neutralising TNFalpha in supernatants of leptin-treated cells, also suggest the involvement of TNFalpha in the leptin-induced TF expression in leukocytes.. This study indicates a novel link between inflammation, obesity and thrombosis by showing that leptin is able to trigger the extrinsic coagulation cascade. This work suggests a possible mechanism of the thrombotic effects of hyperleptinemic-associated clinical disorders.

Topics: Blood Coagulation; Humans; Inflammation; Janus Kinase 2; Leptin; Leukocytes, Mononuclear; Neutrophils; Obesity; Phosphatidylinositol 3-Kinases; Platelet Aggregation; Prothrombin Time; RNA, Messenger; Thromboplastin; Thrombosis; Tumor Necrosis Factor-alpha

Obesity is a major modifiable risk factor for cardiovascular disease. Leptin, the hormone synthesized and released primarily by adipose tissue and found increased in obese individuals, has been implicated in the regulation of inflammation and arterial and venous thrombosis.. To investigate the role of tissue factor (TF), the pivotal agonist of the clotting cascade, as a link between obesity and cardiovascular disease.. In 15 obese patients, plasma levels of leptin and TF as well as TF expression in resting and endotoxin-stimulated mononuclear leukocytes (MN) were increased when compared with healthy donors. In a selected sample of obese patients, loss of body weight led to decreased circulating leptin levels, accompanied by a reduction in plasma TF as well as in TF expression, both in resting and endotoxin-stimulated MN. In subsequent in vitro experiments, leptin was incubated with MN from healthy subjects. Leptin induced TF activity and antigen in a dose-dependent fashion, as assessed by clotting assay and ELISA, respectively. Increased migration of c-Rel/p65 into the nucleus, as determined by EMSA, and development of TF mRNA in monocytes, as assessed by RT-PCR, were observed. Experiments with mitogen-activated protein kinase (MAPK) inhibitors, indicated the involvement of p38 and ERK1/2 pathways.. The presence of TF-expressing MN in blood from obese subjects and the in vitro induction of TF by pharmacologic concentrations of leptin in MN from healthy subjects suggest that TF expression by leptin-stimulated monocytes may contribute to the cardiovascular risk associated with obesity.

Topics: Cardiovascular Diseases; Dimerization; Gene Expression Regulation; Humans; In Vitro Techniques; Leptin; Leukocytes, Mononuclear; Obesity; Proto-Oncogene Proteins c-rel; RNA, Messenger; Thromboplastin; Transcription Factor RelA

Topics: Analysis of Variance; C-Reactive Protein; Female; Homeostasis; Hormone Replacement Therapy; Humans; Lipoproteins; Middle Aged; Obesity; Peptide Fragments; Postmenopause; Prothrombin; Thromboplastin

Hypercoagulability and thrombotic tendency are frequently induced by a variety of stressors. Clinically, aged subjects and obese patients are more susceptible to thrombotic diseases associated with stress, but the underlying mechanisms are unknown. We investigated the expression of a procoagulant gene, tissue factor (TF), in a mouse model of restraint stress. Twenty hours of restraint stress to mice caused a substantial induction of TF mRNA in several tissues. Importantly, the magnitude of induction of TF mRNA by restraint stress was larger in aged mice compared with young mice. In situ hybridization analysis of the stressed aged mice revealed that strong signals for TF mRNA were localized to renal epithelial cells, smooth muscle cells, adventitial cells, and adipocytes but not to vascular endothelial cells. These observations suggest that restraint stress induces the TF expression in a tissue-specific and cell type-specific manner. Genetically obese mice were also hyperresponsive to restraint stress in the induction of TF gene, especially in their livers and adipose tissues. Stress-induced microthrombi formation was pronounced in renal glomeruli and within the vasculature in adipose tissues of aged mice. Tumor necrosis factor-alpha (TNF-alpha) antigen in plasma was elevated by stress in aged mice and obese mice, and pretreatment of mice with anti-TNF-alpha antibody partially attenuated the stress-mediated induction of TF gene in adipose tissues in these mice. These results suggest that the induction of TF gene may increase the risk of stress-associated thrombosis in older and obese subjects and that TNF-alpha may be involved.

Topics: Aging; Animals; Male; Mice; Mice, Mutant Strains; Models, Animal; Obesity; RNA, Messenger; Stress, Physiological; Thromboplastin; Thrombosis; Tissue Distribution; Tumor Necrosis Factor-alpha; Up-Regulation

Changes of the tissue factor (TF) pathway of blood coagulation have been described in diabetes and could be involved in its vascular complications. In order to evaluate the influence of the type of diabetes and of the obesity index and age on these changes, factor VII coagulant activity, factor VII antigen, activated factor VII, monocyte TF expression, and plasma Tissue Factor Pathway Inhibitor (TFPI) were examined in 18 Type 1 and 16 Type 2 diabetic patients compared to non-diabetic control subjects matched for age, sex, and obesity index (Types 1 and 2 controls, respectively). Multicomplicated patients were excluded. FVIIc, FVIIAg, and FVIIa were higher in Type 2 diabetic patients and controls than in Type 1 diabetic patients and controls (P< .03). However, FVIIc and FVIIAg were lower in diabetic patients than in their matched controls (P< .03). Monocyte expression of TF was not different between Types 1 and 2 diabetic patients and their matched controls except for LPS-stimulated monocyte TF activity which was lower in Type 2 diabetic patients than in Type 2 controls (P< .05). Plasma TFPI was slightly but significantly higher in Type 1 diabetic patients than in Type 1 controls (P= .01) and was correlated to glycemia. However, both in Type 2 diabetic patients and controls, TFPI was higher than in Type 1 controls and was correlated with BMI (P< .0003). These results indicate that in not multicomplicated patients, the increase of FVII and TFPI was highly dependent on obesity index and age rather than on diabetes by itself.

Topics: Adult; Age Factors; Antigens; Apolipoproteins; Body Mass Index; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Factor VII; Factor Xa Inhibitors; Female; Glycated Hemoglobin; Humans; Lipoproteins; Male; Middle Aged; Monocytes; Obesity; Reference Values; Thromboplastin

Obesity and insulin resistance are associated with accelerated macrovascular and microvascular coronary disease, cardiomyopathic phenomena, and increased concentrations and activity in blood of plasminogen activator inhibitor type 1 (PAI-1), the primary physiological inhibitor of fibrinolysis.. To determine whether hypofibrinolysis in blood and tissues and its potential sequelae could be attenuated pharmacologically, we studied genetically modified obese mice. By 10 weeks of age, obese mice exhibited increases in left ventricular weight and glucose and immunoreactive insulin in blood. PAI-1 activity in blood measured spectrophotometrically was significantly elevated as well. The difference compared with values in lean controls widened by 20 weeks of age. Perivascular fibrosis in coronary arterioles and small coronary arteries was evident in obese mice 10 and 20 weeks of age, paralleling increases in PAI-1 and tissue factor expression evident by immunohistochemical image analysis, in situ hybridization, and reverse transcription-polymerase chain reaction. Inhibition of ACE activity initiated in obese mice 10 weeks of age and continued for 20 weeks arrested the increase in PAI-1 activity in blood and in cardiac PAI-1 and tissue factor mRNA as well as coronary perivascular fibrosis.. Thus, inhibition of proteo(fibrino)lysis and augmented tissue factor expression in the heart precede and may contribute to the coronary perivascular fibrosis seen with obesity and insulin resistance. Furthermore, inhibition of ACE activity can attenuate all 3 phenomena.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Glucose; Body Weight; Coronary Vessels; Diabetes Mellitus; Fibrinolysis; Fibrosis; Heart Ventricles; Immunohistochemistry; In Situ Hybridization; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Myocardium; Obesity; Organ Size; Peptidyl-Dipeptidase A; Plasminogen Activator Inhibitor 1; RNA, Messenger; Thiazepines; Thromboplastin

Platelet activation is known to participate to the pathogenesis of acute coronary syndromes. Aminophospholipid exposure and microparticles shedding are hallmarks of full platelet activation and may account for the dissemination of prothrombotic seats. Using flow cytometry analysis of annexin V binding to externalized aminophospholipids, we followed platelet procoagulant activity (PPA) and platelet microparticles (PMP) shedding in venous and coronary whole blood samples from 30 patients with unstable angina before and after percutaneous coronary angioplasty (PTCA) and stent implantation. Baseline values of PPA and PMP were significantly more elevated in patients than in control subjects (p < 0.005). PMP percentage was significantly higher in coronary than in venous blood, and in coronary blood of patients with proximal instead of mid/distal lesions of coronary arteries. No enhancement of platelet reactivity to TRAP and collagen was induced by procedure. Whereas activated GpIIb-IIIa and P-selectin expression decreased 24 h and 48 h after procedure, PPA and PMP remained as elevated as before. Thus, flow cytometry is a reliable method for detection of fully activated platelets in whole blood samples. Annexin V binding analysis demonstrates the persistance of in vivo platelet activation, despite the use of antiaggregating agents.

Topics: Aged; Angina, Unstable; Angioplasty, Balloon, Coronary; Annexin A5; Biomarkers; Collagen; Combined Modality Therapy; Comorbidity; Coronary Angiography; Coronary Stenosis; Coronary Vessels; Diabetes Mellitus; Female; Flow Cytometry; Humans; Hypercholesterolemia; Male; Middle Aged; Obesity; P-Selectin; Platelet Activation; Platelet Count; Platelet Glycoprotein GPIIb-IIIa Complex; Proteins; Receptors, Thrombin; Risk Factors; Stents; Thromboplastin; Veins

Altered expression of proteins of the fibrinolytic and coagulation cascades in obesity may contribute to the cardiovascular risk associated with this condition. In spite of this, the zymogenic nature of some of the molecules and the presence of variable amounts of activators, inhibitors, and cofactors that alter their activity have made it difficult to accurately monitor changes in the activities of these proteins in tissues where they are synthesized. Thus, as a first approach to determine whether tissue factor (TF) expression is altered in obesity, this study examined changes in TF mRNA in various tissues from lean and obese (ob/ob and db/db) mice. TF gene expression was elevated in the brain, lung, kidney, heart, liver, and adipose tissues of both ob/ob and db/db mice compared with their lean counterparts. In situ hybridization analysis indicated that TF mRNA was elevated in bronchial epithelial cells in the lung, in myocytes in the heart, and in adventitial cells lining the arteries including the aortic wall. Obesity is associated with insulin resistance and hyperinsulinemia, and administration of insulin to lean mice induced TF mRNA in the kidney, brain, lung, and adipose tissue. These observations suggest that the hyperinsulinemia associated with insulin-resistant states, such as obesity and noninsulin-dependent diabetes mellitus, may induce local TF gene expression in multiple tissues. The elevated TF may contribute to the increased risk of atherothrombotic disease that accompanies these conditions.

Topics: Adipose Tissue; Animals; Brain Chemistry; Gene Expression Regulation; Hyperinsulinism; In Situ Hybridization; Insulin; Insulin Resistance; Kidney; Liver; Lung; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Myocardium; Obesity; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Thromboplastin

Altered expression of proteins of the fibrinolytic and coagulation cascades in obesity may contribute to the cardiovascular risk associated with this condition. We previously reported that plasminogen activator inhibitor 1 (PAI-1) is dramatically up-regulated in the plasma and adipose tissues of genetically obese mice. This change may disturb normal hemostatic balance and create a severe hypofibrinolytic state. Here we show that tissue factor (TF) gene expression also is significantly elevated in the epididymal and subcutaneous fat pads from ob/ob mice compared with their lean counterparts, and that its level of expression in obese mice increases with age and the degree of obesity. Cell fractionation and in situ hybridization analysis of adipose tissues indicate that TF mRNA is increased in adipocytes and in unidentified stromal vascular cells. Transforming growth factor beta (TGF-beta) is known to be elevated in the adipose tissue of obese mice, and administration of TGF-beta increased TF mRNA expression in adipocytes in vivo and in vitro. These observations raise the possibility that TF and TGF-beta may contribute to the increased cardiovascular disease that accompanies obesity and related non-insulin-dependent diabetes mellitus, and that the adipocyte plays a key role in this process. The recent demonstration that TF also influences angiogenesis, cell adhesion, and signaling suggests that its exact role in adipose tissue physiology/pathology, may be complex.

Topics: Adipocytes; Adipose Tissue; Animals; Fibrinolysis; Gene Expression; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Obese; Obesity; Plasminogen Activator Inhibitor 1; RNA, Messenger; Thromboplastin; Thrombosis; Transforming Growth Factor beta

Topics: Blood Coagulation; Blood Glucose; Blood Pressure; Body Constitution; Body Weight; Cholesterol; Factor VII; Factor VIII; Factor X; Fibrinogen; Fibrinolysis; Humans; Male; Middle Aged; Myocardial Infarction; Obesity; Plasminogen; Prothrombin; Sampling Studies; Skinfold Thickness; Smoking; Spirometry; Thromboplastin; Triglycerides; Vital Capacity

Topics: Blood Coagulation Tests; Esterases; Fasting; Glycerides; Humans; Lipoprotein Lipase; Obesity; Thromboplastin; Triglycerides

Topics: Adult; Blood Coagulation; Blood Coagulation Tests; Blood Platelets; Female; Heparin; Humans; Male; Obesity; Thromboplastin