Thrombomodulin Concentrations Research Articles

Endothelium biomarkers endocan and thrombomodulin levels in isolated coronary artery ectasia.

Endothelial dysfunction may play an important role in the evolution of coronary artery ectasia (CAE). Endocan and thrombomodulin (TM) are two biomarkers released from the endothelium that are associated with dysfunction. We aimed to evaluate the levels of these markers in patients with isolated CAE. Thirty-two patients with isolated CAE and thirty-five sex- and age-matched control patients with normal coronary angiograms were enrolled. Serum endocan and TM concentrations were measured with an enzyme-linked immunosorbent assay kit. The basal characteristics of the two groups were similar. Both endocan (1.19 ± 0.18 vs. 1.07 ± 0.15 ng/ml; p = 0.006) and TM (687.28 ± 150.85 vs. 571.27 ± 171.23 pg/ml; p = 0.007) were significantly increased in the CAE group compared to controls. However, no significant differences were detected in the concentration of these markers when we grouped the subjects according to the Markis classification. We found higher endocan and TM levels in isolated CAE patients. However, these markers were not associated with CAE severity as assessed using the Markis classification. The results suggest that these markers play an important role in the development of isolated CAE.

Endotheliopathy of Trauma is an on-Scene Phenomenon, and is Associated with Multiple Organ Dysfunction Syndrome: A Prospective Observational Study.

Trauma patients are vulnerable to coagulopathy and inflammatory dysfunction associated with endotheliopathy of trauma (EoT). In vitro evidence has suggested that tranexamic acid (TXA) may ameliorate endotheliopathy. We aimed to investigate how soon after injury EoT occurs, its association with multiple organ dysfunction syndrome (MODS), and whether TXA ameliorates it. A prospective observational study included 91 trauma patients enrolled within 60 min of injury and 19 healthy controls. Blood was sampled on enrolment and again 4 to 12 h later. ELISAs measured serum concentrations of syndecan-1 and thrombomodulin as biomarkers of EoT. MODS was compared between groups according to biomarker dynamics: persistently abnormal; abnormal to normal; and persistently normal. Timing of EoT was estimated by plotting biomarker data against time, and then fitting generalized additive models. Biomarker dynamics were compared between those who did or did not receive prehospital TXA. Median age was 38 (interquartile range [IQR] 24-55) years; 78 of 91 were male. Median injury severity score (ISS) was 22 (IQR 12-36). EoT was estimated to occur at 5 to 8 min after injury. There were no significant differences in ISS between those with or without prehospital EoT. Forty-two patients developed MODS; 31 of 42 with persistently abnormal; 8 of 42 with abnormal to normal; and 3 of 42 with persistently normal biomarkers; P < 0.05. There were no significant differences between TXA and non-TXA groups. EoT was present at the scene of injury. MODS was more likely when biomarkers of EoT were persistently raised. There were no significant differences between TXA and non-TXA groups. Prehospital interventions aimed at endothelial restoration may represent a clinically meaningful target for prehospital resuscitation.

Coexistence of endothelial dysfunction, fibrinolysis activation and diminished interleukin 6 level in morbid obesity

ABSTRAKTWstęp: Celem pracy była ocena wybranych parametrów dysfunkcji śródbłonka i hemostazy u chorych z otyłością. Badania dotyczące zaburzeń komórek śródbłonka w otyłości ogromnej są w literaturze spotykane zaskakująco rzadko.Materiały i metody: Badanie przeprowadzono u 74 chorych z otyłością ze wskaźnikiem masy ciała (BMI) &gt;40 kg/m2 oraz u 30 zdrowych ochotników z prawidłowym BMI. W osoczu krwi chorych przeprowadzono testy stężenia: rozpuszczalnej formy trombomoduliny (sTM), antygenu czynnika von Willebranda (vWF:Ag), antygenu tkankowego aktywatora plazminogenu (t-PA:Ag) i antygenu inhibitora aktywatora plazminogenu typu 1 (PAI-1:Ag) oraz rozpuszczalnej frakcji selektyny E i P (sE-selektyny i sP-selektyny). Dokonano także pomiaru stężenia interleukiny 6 (Il-6).Wyniki: Wyniki badań wskazały znaczne zwiększenie stężenia sTM, t-PA:Ag, PAI-1:Ag i sE-selektyny oraz istotne zmniejszone stężenie vWF:Ag i sP-selektyny w otyłości ogromnej w porównaniu z grupą kontrolną. Wykazano także w otyłości ogromnej obniżenie stężenia Il-6.Wnioski: W otyłości ogromnej dochodzi do uszkodzenia śródbłonka, co zwiększa ryzyko ewentualnych powikłań zakrzepowo-zatorowych. Zwiększenie składowych układu fibrynolizy oraz hamowanie aktywacji płytek można traktować jako mechanizmy kompensacyjne zmniejszające ryzyko powikłań. Spadek stężenia Il-6 może być wyrazem ograniczania procesu zapalnego, ale równocześnie może to być przyczyna zwiększonej podatności na choroby infekcyjne.

Clinical application of endothelial injury marker in hypertensive patients.

Endothelial damages are one of the most important causes of persistent hypertensive complications. The aim of our study was to discuss the relationship between the molecular markers of endothelial damage, thrombomodulin, and complications in hypertension. A total 132 cases of hypertensive patients, including 13 patients with damage of target organs, were selected as research subjects. And grouping was based on different levels of blood pressure. The blood pressure and thrombomodulin levels were detected among all cases, and their drinking, smoking, and other medical records were tracked. Higher plasma concentration of thrombomodulin was demonstrated in subjects with hypertensive complications compared with without complications [24.5 (18.1,37.55) vs 12.1 (9.1,22.3)TU/mL, P=.001, respectively]. The optimum thrombomodulin cutoff value was determined to be more than 15.5TU/mL, with a sensitivity of 92.3% and a specificity of 63%. With the increase in blood pressure level, thrombomodulin levels in three groups gradually raised [6.15(5.475,12.75) vs 9.75(7.725,13.35) vs 16.45 (10.125,23.725)TU/mL, P=.007, respectively]. With the increase in blood pressure and the occurrence of complications, thrombomodulin showed an increasing trend, which was caused by an increase in the degree of endothelial injury. So, thrombomodulin may serve as a clinically meaningful marker of the progression of hypertension.

Poor microcirculatory flow dynamics are associated with endothelial cell damage and glycocalyx shedding after traumatic hemorrhagic shock.

Endothelial cell damage and glycocalyx shedding after trauma can increase the risk of inflammation, coagulopathy, vascular permeability, and death. Bedside sublingual video-microscopy may detect worse flow and perfusion associated with this endotheliopathy. We compared markers of endotheliopathy with physical flow dynamics after traumatic hemorrhagic shock. Sublingual incident dark field video-microscopy was performed at three time points after injury (<10 hours, 10-30 hours, and 30-50 hours). Values for microcirculatory flow index (MFI), Point Of carE Microcirculation assessment (POEM) score, proportion of perfused vessels (PPV), microcirculatory heterogeneity index (MHI), perfused vessel density (PVD), and total vessel density (TVD) were obtained. ELISAs were performed to measure concentrations of thrombomodulin and syndecan-1 as biomarkers of endothelial cell damage and glycocalyx shedding respectively. Flow parameters were dichotomized to above and below average, and biomarkers compared between groups; below average MFI, POEM, PPV, PVD, and TVD, and above average MHI were considered poor microcirculatory flow dynamics. A total of 155 sublingual video-microscopy clips corresponding to 39 time points from 17 trauma patients were analyzed. Median age was 35 (IQR 25-52); 16/17 were men. Within 10 hours of injury, syndecan-1 concentrations were significantly higher compared to 17 age- and sex-matched healthy controls (30 [IQR 20-44] ng/mL) for worse TVD (78 [IQR 63-417] ng/mL), PVD (156 [IQR 63-590] ng/mL), PPV (249 [IQR 64-578] ng/mL), MFI (249 [IQR 64-578] ng/mL), MHI (45 [IQR] 38-68) ng/mL), and POEM scores (108 [IQR 44-462] ng/mL) (all p < 0.01). Thrombomodulin was also raised within 10 hours of injury when compared to healthy controls (2.9 [IQR 2.2-3.4] ng/mL) for worse PPV (4.1 [IQR 3.4-6.2] ng/mL) and MFI (4.1 [IQR 3.4-6.2] ng/mL) (both p < 0.05). Endothelial cell damage and glycocalyx shedding are associated with worse flow, density, and heterogeneity within microvessels after traumatic hemorrhagic shock. The clinical utility of these biomarkers and flow parameters at the bedside are yet to be elucidated. Prognostic study, level III.

Association between hemostatic markers, serum lipid fractions and progression of cerebral small vessel disease: A 2-year follow-up study

IntroductionLittle is known if hemostatic markers and serum lipid fractions can predict further radiological progression beyond vascular risk factors in cerebral small vessel disease (SVD). We investigated whether they are associated with SVD radiological progression and if they are related to different SVD clinical manifestations. MethodsA single-center, prospective, cohort study with 2 years of radiological follow-up was performed in consecutive patients with different SVD manifestations. The study group consisted of 123 patients: 49 with lacunar stroke (LS), 48 with vascular dementia (VaD) and 26 with vascular parkinsonism (VaP). We assessed SVD progression by a visual SVD scale. We determined the relationship between serum or plasma concentrations of tissue factor (TF), thrombomodulin, beta-thromboglobulin (BTG), fibrinogen, D-dimer and total cholesterol, HDL-C, LDL-C, triglycerides and SVD progression by logistic regression analysis. Results34.9% patients had SVD radiological progression: 43% had isolated WMLs progression, 23.2% had new lacunes, 34.8% had both WMLs progression and new lacunes. Fibrinogen [OR 1.02 (95% CI 1.006–1.011] was significantly associated with risk of new lacunes or WMLs progression regardless of the clinical SVD manifestation. While low HDL [OR 0.96 (0.93–1)] and TF [OR 1.07 (0.99–1.1)] were marginally associated with new lacunes, BTG [OR 1.005 (0.99–1.01)] was associated with WMLs progression. ConclusionWe found a relationship between fibrinogen and risk of radiological progression of SVD regardless of the clinical SVD manifestation. In addition, lower HDL and increased TF predicted development of new lacunes, and higher BTG was associated with risk of WMLs progression.

The relation of thrombomodulin G33A and C1418T gene polymorphisms to the risk of acute myocardial infarction in Egyptians

BackgroundAcute myocardial infarction (AMI) is one of the major causes of morbidity and mortality worldwide. There is an increased interest in the genetic risk factors in the pathogenesis of ischemic heart disease. Thrombomodulin (TM), a natural anticoagulant, may play a critical role in the pathogenesis of AMI. Aim of the studyTo assess whether Thrombomodulin (TM) G33A and C1418T gene polymorphisms are related to the risk of AMI in Egyptians or not. Subjects and methods102 AMI patients were recruited vs 110 healthy controls. For every subject, measurement of plasma soluble Thrombomodulin level was done by enzyme-linked immunosorbent assay (ELISA). Further, DNA samples were genotyped by PCR-RFLP method for the TM G33A polymorphism and by PCR-ASO for the TM C1418T polymorphism. ResultsOur results revealed that the C1418T gene polymorphism was significantly associated with increased risk of AMI (CT: OR=2.34, 95% CI=1.28–4.29, P=0.006; TT: OR=8.03, 95% CI=0.97–66.47, P=0.026; CT+TT: OR=2.65, 95% CI=1.47–4.78, P=0.001; T allele: OR=2.51, 95% CI=1.51–4.18, P<0.001). On the other side, the TM G33A polymorphism was not detectable in any of patients or controls. Further, plasma soluble TM concentrations were higher in AMI patients, compared to the control group (P<0.001). ConclusionsTM 1418C>T gene polymorphism, but not TM 33-G>A, may be associated with an increased risk of AMI in the Egyptian population. These results may have clinical implication in the management of AMI in the future.

Modulation of the activated protein C pathway in severe haemophilia A patients: The effects of thrombomodulin and afactor V-stabilizing fab.

The thrombomodulin (TM)/activated protein C (APC) system is a key regulator of haemostasis, limiting amplification and propagation of the formed blood clot to the injury site. Dampening APC's inhibition of factor V (FV) and factor VIII (FVIII) may be a future strategy in developing next-generation therapeutic targets for haemophilia treatment. To determine ex vivo the respective concentration-dependent effects of TM and a FV-stabilizing Fab on the APC regulatory pathway in severe FVIII-deficient blood and plasma. Ten severe haemophilia A subjects and one healthy control were enrolled. Blood was spiked with TM (0, 1, 2.5, 5, 10, 20.0nmol/L) and FV-stabilizing Fab (0, 3, 15, 65, 300nmol/L). The respective effects were compared to FVIII concentrations of 3- and 10% using rotational thromboelastometry clotting time (CT) and thrombin generation analysis (TGA). With 1 and 2.5nmol/L TM, 5% FVIII resulted in CT similar to the absence of TM, suggesting it completely reversed the effect of APC. Increasing TM concentrations also reduced peak thrombin generation and ETP. The addition of 300nmol/L FV-stabilizing Fab returned CT to nearly baseline, but for most subjects was less than the effects of 3- or 10% FVIII. The FV-stabilizing Fab produced similar or greater thrombin generation compared to samples with 3- or 10% FVIII. The FV-stabilizing Fab resulted in enhanced CT and TGA parameters consistent with FVIII levels of 3- and 10%. Additional studies need to further characterize how modulating the APC pathway may prove beneficial in developing new haemophilia drug targets.

Blood Hemostatic Changes During an Ultraendurance Road Cycling Event in a Hot Environment

This study aims to examine blood hemostatic responses to completing a 164-km road cycling event in a hot environment. Thirty-seven subjects (28 men and 9 women; 51.8±9.5 [mean±SD] y) completed the ride in 6.6±1.1 hours. Anthropometrics (height, body mass [taken also during morning of the ride], percent body fat [%]) were collected the day before the ride. Blood samples were collected on the morning of the ride (PRE) and immediately after (IP) the subject completed the ride. Concentrations of platelet, platelet activation, coagulation, and fibrinolytic markers (platelet factor 4, β-thromboglobulin, von Willebrand factor antigen, thrombin-antithrombin complex, thrombomodulin, and D-Dimer) were measured. Associations between changes from PRE- to IP-ride were examined as a function of event completion time and subject characteristics (demographics and anthropometrics). All blood hemostatic markers increased significantly (P < .001) from PRE to IP. After controlling for PRE values, finishing time was negatively correlated with platelet factor 4 (r = 0.40; P = .017), while percent body fat (%BF) was negatively correlated with thrombin-antithrombin complex (r = -0.35; P = .038) and to thrombomodulin (r = -0.36; P = .036). In addition, male subjects had greater concentrations of thrombin-antithrombin complex (d = 0.63; P < .05) and natural logarithm thrombomodulin (d = 6.42; P < .05) than female subjects. Completing the 164-km road cycling event in hot conditions resulted in increased concentrations of platelet, platelet activation, coagulation, and fibrinolytic markers in both men and women. Although platelet activation and coagulation occurred, the fibrinolytic system markers also increased, which appears to balance blood hemostasis and may prevent clot formation during exercise in a hot environment.

Clinical usefulness of videocapillaroscopy and selected endothelial cell activation markers in people with Type 1 diabetes mellitus complicated by microangiopathy

PurposeMicrovascular abnormalities are one of the most important causes of persistent diabetic complications. The aim of our study was to compare microvascular changes examined by nailfold videocapillaroscopy (NVC) examination with serum concentrations of vascular endothelial growth factor (VEGF), soluble thrombomodulin (sTM) and endothelin-1 (ET-1) in people with Type 1 diabetes with and without microangiopathy. Material/methodsThe study included 106 people with Type 1 diabetes and 40 healthy controls. All participants were evaluated by extensive clinical, laboratory and capillaroscopic studies. NVC was performed using a stereomicroscope SZ 4045 (Olympus, Germany). The intensity of morphological changes was graded from 0 to 3. Serum levels of VEGF, sTM and ET-1 were determined by an enzyme-linked immunosorbent assay (ELISA). ResultsMorphological changes were observed by NVC in 86 out of 106 (81%) people with Type 1 diabetes mellitus. Severe capillaroscopic changes (score 3) were seen in 32 out of 54 (59%) people with microangiopathy, but in only seven out of 52 (13%) individuals without microangiopathy. Higher serum concentration of VEGF (p<0.001), ET-1 (p<0.001) and sTM (p<0.05) were demonstrated in people with diabetes complicated with microangiopathy compared to healthy controls. Moreover, comparison between people with and without microangiopathic complications showed a significantly higher capillaroscopic score and sTM serum concentration in the group with retinopathy (p<0.001) nephropathy (p<0.001) and neuropathy (p<0.01). ConclusionsOur results suggest that abnormalities in NVC may reflect the extent of microvascular involvement and associated with higher VEGF, sTM and ET-1 serum levels, as well as with microangiopathic complications in diabetic people.

Blood markers of fibrinolysis and endothelial activation in canine babesiosis

BackgroundCanine babesiosis is a tick-borne disease caused by hemoprotozoan parasites of the genus Babesia. The disease can be clinically classified into uncomplicated and complicated forms. The aim of this study was to assess the level of endothelial activation and alterations in the fibrinolytic pathway during canine babesiosis.ResultsBlood samples were collected on the day of admission and on the 6th day after treatment with imidocarb propionate, from 30 dogs of various breeds and of both sexes with naturally occurring babesiosis caused by B. canis. In this prospective study, plasminogen activity was assessed using a chromogenic assay, and concentrations of high mobility group box-1 protein (HMGB-1), intercellular adhesive molecule-1 (ICAM-1), vascular adhesive molecule-1 (VCAM-1), soluble urokinase receptor of plasminogen activator (suPAR), thrombin activatable fibrinolysis inhibitor (TAFI), soluble thrombomodulin (TM) and plasminogen activator inhibitor-1 (PAI-1) were determined using a canine specific ELISA. Concentrations of TM, HMGB-1, VCAM-1 and suPAR were increased in dogs with babesiosis at admission compared to healthy dogs. After treatment, concentrations of TM were lower in infected dogs compared to healthy dogs. Dogs with babesiosis also had increased concentrations of TM, ICAM-1 and HMGB-1 and decreased plasminogen and PAI-1 at presentation compared to day 6 after treatment. Dogs with complicated babesiosis had higher concentrations of TM, HMGB1 and TAFI at admission compared to the 6th day.ConclusionsBiomarkers of endothelial activation and fibrinolysis were altered in dogs with babesiosis. Further studies into their usefulness as biomarkers of disease severity or prognosis is warranted.

The influence of the atrial fibrillation episode duration on the endothelial function in patients treated with pulmonary veins isolation.

Atrial fibrillation (AF) is associated with endothelial dysfunctions. The aim of the study was to assess the influence of the duration of an AF episode on the endothelial function. The study included 65 patients with persistent AF qualified for the percutaneous pulmonary veins isolation. Patients were divided into three subgroups with increasing time of the duration of AF episode, as follow: ≤ 7 months (n = 24 patients), from 7 to 14 months (n = 18 patients) and ≥ 14 months (n = 23 patients). Concentrations of endothelin-1 (ET-1), thrombomodulin (TM) and VEGF in serum were measured. Median age in the whole study group was 56 years with 84.6% of males. Patients with longer lasting AF episode had a higher body mass index and less incidence of heart failure. Median values of ET1, TM and VEGF were 3.1 (2.5-3.5) pg/mL, 3126.0 (2827.2-3594.1) pg/mL and 464.6 (323.6-630.1), respectively. Among increasing tertiles of AF episode duration, median ET-1 serum concentrations were as follows: 3.3 (2.8-3.7) pg/mL, 3.06 (2.6-3.4) pg/mL, 2.7 (2.3-3.2) pg/mL, p = 0.019, respectively. There was also a trend towards negative association of serum VEGF level with AF episode duration. Serum biomarkers' levels were not associated with total AF duration. AF episode duration may be associated with the endothelial function, assessed by serum biomarkers. ET-1 serum concentrations are significantly lower in patients with longer AF. ET-1, TM and VEGF have no correlation with total AF duration.

Pentraxin 3 as a new indicator of cardiovascular‑related death in patients with advanced chronic kidney disease.

INTRODUCTION Pentraxin3 (PTX3) play an important role in the inflammatory response, taking part in recognizing pathogens and damaged tissues. OBJECTIVES The aim of the study was to assess the relationship between PTX3 levels and all-cause and cardiovascular (CV) mortality in chronic kidney disease (CKD) patients during five-year observation period. PATIENTS AND METHODS The study comprised 78 patients (51 hemodialyzed, 27 predialysis). The examined parameters included PTX3, calcium, phosphate, iPTH, interleukin-6 (IL-6), fibroblast growth factor 23 (FGF-23), osteopontin (OPN), osteoprotegerin (OPG), osteocalcin (OC), osteopontin (OPN), osteoprotegerin (OPG), osteocalcin, tumor necrosis factor receptor II (TNF-R II), transforming growth factor-β (TGF-β), hepatocyte growth factor (HGF), stromal cell-derived factor α (SDF1α), and thrombomodulin (TM). In a subgroup of 45 patients, fragments of radial artery obtained during creation of hemodialysis access were stained for calcifications. In 51 patients, ultrasonography was performed to assess intima-media thickness (CCA-IMT). RESULTS Median serum concentration of PTX3 was 1.43 (0.74-2.50) ng/ml. Higher concentrations of fibrinogen, CRP, IL-6, TNF-R II, TGFβ1, HGF, OPN, OPG, FGF-23, TM, SDF1α, lower albumin and uric acid levels were observed in patients with PTX3 above the median. During follow-up, 27 patients (35%) died, including 25 due to CV causes. In contrast to CRP, baseline PTX3 predicted CV mortality independently of classical CV risk factors. Also, PTX3 concentrations significantly predicted mortality after adjustment for age, baseline dialysis status, serum OPG and CRP, radial artery calcifications, and CCA-IMT. CONCLUSIONS We postulate that PTX3 might be an early marker of CV mortality in patients with advanced CKD yet before the increase of specific marker for systemic inflammation like hsCRP.

The Association of Serum Thrombomodulin with Endothelial Injuring Factors in Abdominal Aortic Aneurysm.

Background. The aim of the present study was to evaluate the concentration of serum thrombomodulin (sTM) in the AAA patients and to examine its correlation with various factors which may potentially participate in the endothelial injury. Materials and Methods. Forty-one patients with AAA were involved and divided into subgroups based on different criteria. Concentration of sTM was measured using enzyme-linked-immunosorbent assay (ELISA). The results were compared with those obtained in 30 healthy age- and sex-matched volunteers. Results. The higher concentration of sTM was observed in AAA patients compared with those in controls volunteers [2.37 (1.97–2.82) ng/mL versus 3.93 (2.43–9.20) ng/mL, P < 0.001]. An elevated sTM associated significantly with increased triglycerides (TAG) [P = 0.022], cholesterol [P = 0.029], hsCRP [P = 0.031], and advanced glycation end products (AGEs) [P = 0.033]. Conclusions. The elevation of serum sTM level suggests that endothelial damage occurs in AAA pathogenesis. The correlations observed indicate that lipids abnormalities, inflammation, and oxidative stress may be involved in this destructive process.

Puerarin offsets the anticoagulation effect of warfarin in rats by inducing rCyps, upregulating vitamin K epoxide reductase and inhibiting thrombomodulin.

The current study was conducted to investigate the potential pharmacokinetic and pharmacodynamic interactions between warfarin and puerarin which is the most abundant component in Pueraria lobata (Gegen). In vivo and ex vivo rat models were used to reveal the underlying mechanisms of such interactions. Apart from one control group, five groups of Sprague-Dawley rats were treated with warfarin, oral puerarin, oral puerarin with warfarin, intravenous puerarin, intravenous puerarin with warfarin. The treatment lasted for 5 consecutive days. Thereafter, the levels of warfarin, warfarin metabolites and puerarin in plasma of these rats were monitored and compared. The rCyps activity and expression in rat livers of different treatment groups were assessed. The prothrombin time was observed. The vitamin K epoxide reductase (VKOR) activity and expression in rat livers were evaluated. Thrombomodulin activity and expression in the rat lung and rat plasma were assessed. The soluble thrombomodulin (sTM) concentrations of different treatment groups were examined. Intravenously administered puerarin altered the pharmacokinetics of warfarin significantly by shortening t1/2 , decreasing AUC0-96 h and increasing the clearance of warfarin. Further mechanistic studies suggested that both oral and intravenous administration of puerarin significantly induced the activities and expressions of rCyp2b1, rCyp2c6 and rCyp1a1. In addition, co-administration of puerarin reduced the prothrombin time of rat plasma by enhancing VKOR and inhibiting thrombomodulin. Puerarin increased warfarin metabolism and offset warfarin anticoagulation by inducing rCyps, upregulating VKOR and inhibiting thrombomodulin in rats. The clinical impact of such potential interactions warrants further verification. Copyright © 2016 John Wiley & Sons, Ltd.

Relationship between endothelial function and platelet hemostasis in patients with a good compensation of type 2 diabetes mellitus and hypertension.

Background. Disorders of hemostasis in patients with arterial hypertension and diabetes mellitus type 2 are complex: growing aggregative activity of platelets and red blood cells, activation and degranulation of platelet antiaggregatory potential endothelium; reduced anticoagulant and fibrinolytic activity of blood. Objective. The aim of this study is to determine the relationships between endothelial dysfunction, the degree of renal function damage, lipidemic profile and morphological changes of vascular-platelet hemostasis in patients with good compensation of type 2 diabetes mellitus and arterial hypertension.. Methods. In 69 patients with good glycemic compensation using clinical, laboratory, morphological methods and correlational analysis were identified association between endothelial dysfunction, degree of renal function damage, lipidemic profile and morphological changes of vascular-platelet hemostasis. Results. Results of correlation analysis showed the presence of credible negative relation between the content of unactivated platelets and concentrations of endothelin-1 (r=-0.53; p<0.05), von Willebrand factor (r=-0.68; p<0.05) and thrombomodulin (r=-0.55; p<0.05). The largest number and strength of correlations between morphological indicators of intravascular platelet activation and studied clinical and laboratory parameters were observed with admiration to the activated and aggregated forms of cells. In particular, elevated levels of activated platelets in patients of this contingent had reliable high degree of direct correlation with the content of glycated hemoglobin (r=+0.79), systolic blood pressure (r=+0.63), the concentration of endothelial dysfunction markers, including the level of albuminuria (r=+0.73), as well as with the values of total cholesterol (r=+0.64) and low density lipoprotein cholesterol (r=+0.79). On the level of endothelin-1 and thrombomodulin concentration was found positive linear correlation, but alpha-granules located in shut inverse correlation not only with endothelin-1 (r=-0.57; p<0.05), as well as with the concentration of glycated hemoglobin (r=-0.76; p<0.05) and with dyslipidemic changes. Increased platelet aggregation activity in patients with good glycemic compensation, which was manifested in a twofold increase in the content of circulating small units was significantly correlated with the level of glycated hemoglobin (r=+0.66) and the values of systolic blood pressure (r=+0.58), as well as concentrations of markers of endothelial dysfunction and renal function, but did not have any significant relationships with blood lipids in patients of this contingent. Conclusion. It has been established that in the good glycemic control morphological criteria of platelet hemostasis damage clearly correlated with markers of endothelial dysfunction, but did not show significant relationships with indicators of renal function and blood lipid profile.

A Mathematical Model of Venous Thrombosis Initiation

We present a mathematical model for the initiation of venous thrombosis (VT) due to slow flow and the consequent activation of the endothelial cells (ECs) lining the vein, in the absence of overt mechanical disruption of the EC layer. It includes all reactions of the tissue factor (TF) pathway of coagulation through fibrin formation, incorporates the accumulation of blood cells on activated ECs, accounts for the flow-mediated delivery and removal of coagulation proteins and blood cells from the locus of the reactions, and accounts for the activity of major inhibitors including heparan-sulfate-accelerated antithrombin and activated protein C. The model reveals that the occurrence of robust thrombin generation (a thrombin burst) depends in a threshold manner on the density of TF on the activated ECs and on the concentration of thrombomodulin and the degree of heparan-sulfate accelerated antithrombin activity on those cells. Small changes in any of these in appropriate narrow ranges switches the response between “no burst” and “burst.” The model predicts synergies among the inhibitors, both in terms of each inhibitor’s multiple targets, and in terms of interactions between the different inhibitors. The model strongly suggests that the rate and extent of accumulation of activated monocytes, platelets, and MPs that can support the coagulation reactions has a powerful influence on whether a thrombin burst occurs and the thrombin response when it does. The slow rate of accumulation of cells supporting coagulation is one reason that the progress of VT is so much slower than that of arterial thrombosis initiated by subendothelial exposure.

Inorganic Nitrate Supplementation in Young and Old Obese Adults Does Not Affect Acute Glucose and Insulin Responses but Lowers Oxidative Stress

Background: Aging and obesity are associated with raised oxidative stress and a reduction of nitric oxide (NO) bioavailability, with subsequent decline in insulin sensitivity and endothelial function. Inorganic nitrate is converted into NO via a 2-step reduction process and may be an effective nutritional intervention to modify vascular and metabolic functions.Objectives: This study tested whether inorganic nitrate supplementation improved glucose disposal and attenuated the acute effects of hyperglycemia on oxidative stress, inflammation, and vascular function in young and old obese participants.Methods: Ten young (aged 18–44 y) and 10 old (aged 55–70 y) obese participants consumed 75 g glucose followed by either potassium nitrate (7 mg/kg body weight) or potassium chloride (placebo) in a randomized, double-blind crossover design. Resting blood pressure (BP), endothelial function, and blood biomarkers were measured for 3 h postintervention. Biomarkers included plasma nitrate/nitrite (NOx), glucose, insulin, cyclic GMP, interleukin 6, 3-nitrotyrosine, E- and P-selectins, intercellular adhesion molecule 3 (ICAM-3), and thrombomodulin, as well as superoxide in freshly isolated peripheral blood mononuclear cells (PBMCs).Results: Inorganic nitrate supplementation did not affect plasma glucose (P = 0.18) or insulin (P = 0.26) responses. The increase in plasma NOx concentrations 3 h after the administration of inorganic nitrate was significantly higher in young than in old participants (234% increase compared with 149% increase, respectively, P < 0.001). Plasma 3-nitrotyrosine concentrations declined significantly after inorganic nitrate supplementation compared with placebo (3 h postdose, 46% decrease compared with 27% increase, respectively, P = 0.04), and a similar nonsignificant trend was observed for superoxide concentrations (3 h postdose, 16% decrease compared with 23% increase, respectively, P = 0.06). Plasma cyclic GMP, ICAM-3, and thrombomodulin concentrations differed between young and old participants (P < 0.01). Inorganic nitrate supplementation did not improve BP or endothelial function.Conclusions: Oral supplementation with inorganic nitrate did not improve glucose and insulin responses but reduced oxidative stress in old individuals during acute hyperglycemia. This trial was registered at http://www.controlled-trials.com as ISRCTN42776917.

Highly sensitive turn-on fluorescence detection of thrombomodulin based on fluorescence resonance energy transfer

As an integral glycoprotein on the surface of endothelial cells, thrombomodulin (TM) has very high affinity for thrombin. TM has been regarded to be a marker of endothelial damage since it can be released during endothelial cell injury. In this work, a highly sensitive fluorescence method for the quantitative detection of TM was developed. TM antibody (Ab) and bovine serum albumin (BSA) were bound on gold nanoparticles (AuNPs) to construct BSA-AuNPs-Ab nanocomposites and they were characterized by transmission electron microscope and UV–vis spectrophotometry. The fluorescence of acridine orange (AO) was quenched by the prepared gold nanocomposites based on fluorescence resonance energy transfer (FRET). In the presence of TM, the fluorescence was turned on due to the effective separation of AO from the surface of gold nanocomposites. Under optimum conditions, the enhanced fluorescence intensity displayed a linear relationship with the logarithm of the TM concentration from 0.1pgmL−1 to 5ngmL−1 with a low detection limit of 12fgmL−1. The release of soluble thrombomodulin (sTM) by the injured HUVEC-C cells in the presence of H2O2 was investigated using the proposed method. The released sTM content in the growth medium was found to be increased with the enhancement of contact time of the cells with H2O2.

Abstract 34: Impact of Thrombomodulin and Thrombin-activatable Fibrinolysis Inhibitor on the Anti-coagulant and Pro-fibrinolytic Effects of Rivaroxaban

Rivaroxaban is a novel oral anticoagulant that directly inhibits factor Xa and has recently been implemented as a favorable alternative to warfarin in anticoagulation therapy. Rivaroxaban effectively reduces the generation of thrombin, which plays a major role in the activation of thrombin activatable fibrinolysis inhibitor (TAFI) to TAFIa. Activated TAFI functions by downregulating fibrinolysis, and this effect is highly dependent on the availability of thrombomodulin (TM), as the thrombin-TM complex activates TAFI with a 1250-fold greater efficiency than thrombin alone. Additionally, a naturally occurring SNP in the gene encoding TAFI gives rise to a Thr325Ile polymorphism that increases the stability and antifibrinolytic potential of TAFIa. Since inhibition of thrombin generation could lead to decreased TAFIa formation, we hypothesized that these parameters could influence the pharmacodynamics and pharmacogenomics of rivaroxaban. To assess this, effects on coagulation and fibrinolysis were measured using an in vitro plasma clot lysis assay. Rivaroxaban and TM were titrated into TAFI-deficient plasma in the presence or absence of 10 nM wild-type or T325I recombinant TAFI. With increasing concentrations of rivaroxaban, clot formation latency was accordingly increased. TM further delayed clot formation, and this effect was equal in the absence or presence of either TAFI variant. Rivaroxaban was also shown to decrease the rate of coagulation, which was decreased further at higher concentrations of TM. The presence of either TAFI variant also seemed to decrease clot formation rate at higher levels of rivaroxaban and TM. At all concentrations of TM, TAFI-dependent resistance to fibrinolysis was attenuated by rivaroxaban. The effect of rivaroxaban was, however, greater for wild-type TAFI than for the T325I variant. In conclusion, rivaroxaban exhibits TAFI-dependent profibrinolytic effects that are influenced by the levels of TM and the by intrinsic stability of TAFIa. TM also affected the dynamics of coagulation. These findings suggest a role for the anatomical location of a procoagulant stimulus and plasma TM-altering disease phenotypes in the pharmacodynamics and a role for the T325I polymorphism in the pharmacogenomics of rivaroxaban.