Endothelial Plasminogen Activator Inhibitor Research Articles

Selected Factors of Vascular Changes: The Potential Pathological Processes Underlying Primary Headaches in Children.

The prevalence, social consequences and complicated pathogenesis make headaches in children a significant clinical issue. Studies in adults suggest that primary headaches could be the first sign of atherosclerosis and platelet aggregation. To analyze the blood levels of selected biomarkers of vascular changes potentially associated with a higher risk of atherosclerosis in children with primary headaches. The medical family history, brain-derived neurotrophic factor (BDNF), soluble CD40 ligands (sCD40L), endothelial plasminogen activator inhibitor (PAI I), vascular endothelial growth factor (VEGF) and intima-media thickness (IMT) measurements were performed in the 83 children (52 with primary headaches, 31 controls). Selected factors were compared with basic laboratory parameters that are potentially related to atherosclerosis: C-reactive protein (CRP) and lipid concentration. There were no significant differences in biomarkers of vascular changes in the study group and controls in general. In the study group, boys had a higher BDNF level than girls (p = 0.046). Normal-weight migraine patients had significantly higher PAI-I levels than controls (p = 0.034). A positive correlation between PAI-1 and triglycerides (TG) was observed. IMT did not differ between children with primary headaches and controls; however, IMT showed a positive correlation with BMI z-score and TG. Children with headaches had, more often, a positive family history of cardiovascular disease (p = 0.049). There were no clear clinical changes indicative of atherosclerosis in the study population. However, some trends are visible. Primary headaches are more often related to a family history of cardiovascular diseases. IMT is associated with TG levels and BMI z-score. The measured biomarkers of vascular changes show mutual relations.

The possible mediatory role of adipokines in the association between low carbohydrate diet and depressive symptoms among overweight and obese women.

BackgroundPrevious studies showed the possible association between obesity, dietary pattern, and depressive symptoms. Due to the lack of enough data to confirm the association of obesity and depression in the Middle East, here, we aimed to explore the possible mediatory role of adipokines Galectin-3, transforming growth factor-beta (TGF-β), and endothelial plasminogen activator inhibitor (PAI-1) in the association between low carbohydrate diet (LCD) and depressive symptoms.MethodsA total of 256 women aged 17–56 years old were grouped based on their LCD score. Depression anxiety stress scales-21 (DASS-21) self-administered questionnaire was used to evaluate the three negative emotional states of stress, depressive symptoms, and anxiety. Body composition and dietary intake were assessed. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of Galectin-3, TGF-β, and PAI-1.ResultsNo significant difference was observed regarding Galectin-3, TGF-β, and PAI-1 levels between the groups with dissimilar adherence to LCD or the groups with different levels of depressive symptoms (P>0.05). However, there was a negative association between LCD score as a covariant and depressive symptoms as an independent variable (P = 0.02) and remarkably, a regression model linear analysis using Galectin-3, TGF-β, and PAI-1 as confounding variables indicated the mediatory role of these adipokines in this association (P>0.05). In other words, adipokines eliminated the significance of the relationship between adherence to LCD and depressive symptoms.ConclusionIt seems that higher adherence to LCD is probably associated with a lower prevalence of depressive symptoms in obese adults through the mediatory role of adipokines.

Sirtuin 5 promotes arterial thrombosis through endothelial plasminogen activator inhibitor-1

Background and Aims: Arterial thrombosis as a result of plaque rupture or erosion is the crucial event in most CV events. To date, the role of SIRT5 as a putative mediator of arterial thrombosis remains unknown.

Headache in Children: Selected Factors of Vascular Changes Involved in Underlying Processes of Idiopathic Headaches.

Headaches are common complaints in children. The International Classification of Headache Disorders, 3rd edition (beta version), defines more than 280 types of headaches. Primary headaches refer to independent conditions that cause pain and include migraine, tension-type headaches (TTH), and trigeminal autonomic cephalalgias (TACs). Several agents are involved in the pathogenesis of headaches. The factors associated with predisposition to atherosclerosis seem to be particularly important from the clinical point of view. The influence of obesity on the incidence of headaches has been well established. Moreover, idiopathic headaches, especially migraine, are thought to be one of the first signs of disorders in lipid metabolism and atherosclerosis. The risk of migraine increases with increasing obesity in children. Another factor that seems to be involved in both obesity and headaches is the adiponectin level. Recent data also suggest new potential risk factors for atherosclerosis and platelet aggregation such as brain-derived neurotrophic factor (BDNF), sCD40L (soluble CD40 ligand), serpin E1/PAI I (endothelial plasminogen activator inhibitor), and vascular endothelial growth factor (VEGF). However, their role is controversial because the results of clinical studies are often inconsistent. This review presents the current knowledge on the potential markers of atherosclerosis and platelet aggregation, which may be associated with primary headaches.

2182Sirtuin 5 regulates arterial thrombosis by modulating endothelial plasminogen activator inhibitor-1

Abstract Introduction Arterial thrombosis as a result of plaque rupture or erosion is a crucial event in myocardial infarction and stroke. Oxidative stress and inflammation promote endothelial dysfunction and play a pivotal role in destabilization of the atherosclerotic plaque. Sirtuin 5 (SIRT5) is a member of the sirtuin protein family with function as a NAD+-dependent protein desuccinylase and demalonylase. Being implicated in the regulation of different pathophysiological processes among which production of reactive oxygen species and transcription of inflammatory mediators, SIRT5 plays a role in the development of several cardiovascular diseases such as myocardial infarction and stroke. To date, the possible involvement of SIRT5 as a mediator of arterial thrombosis remains to be investigated. Purpose In this study we investigate the putative role of this protein in arterial thrombosis by using an established in vivo mouse model. The translational value of animal findings as well as the molecular mechanism underlying the observed effect will be investigated also in primary human aortic endothelial cells (HAECs). Methods SIRT5 knockout (KO) as well as SIRT5 transgenic (TG) animals were used for in vivo experiments. HAECs treated with SIRT5 silencing RNA (si-SIRT5) and stimulated with tumor necrosis factor (TNF)-α were used for in vitro assays. Results When compared to WT animals, SIRT5 KO mice display blunted carotid artery thrombus formation as underlined by delayed time to occlusion in a photochemical injury model. Oppositely, in SIRT5 TG mice the formation of an occlusive thrombus is accelerated (Fig 1). Mechanistically, SIRT5 KO and WT animals show no difference in terms of vascular tissue factor (TF) activity, TF concentration in plasma and expression of TF pathway inhibitor (TFPI) in the aorta. In line with the observed reduced thrombogenicity, SIRT5 KO animal express reduced level of the pro-thrombotic plasminogen activator-1 (PAI-1), as assessed by western blot in aorta lysate. Of interest, SIRT5 genetic deletion does not affect platelet aggregation, as assessed by ex-vivo collagen-induced aggregometry. In HAECs, SIRT5-silencing inhibits PAI-1 expression in response to TNF-α. Real-time polymerase chain reaction revealed that inhibition of PAI-1 expression occurs at the mRNA level. This effect is mediated by reduced activation of the MAP kinase Erk 1/2, but not JNK (Fig 1). Conclusions SIRT5 mediates arterial thrombosis by increasing endothelial PAI-1 expression. Hence, SIRT5 may be an effective therapeutic target in the context of atherothrombosis.

Endothelial PAI-1 (Plasminogen Activator Inhibitor-1) Blocks the Intrinsic Pathway of Coagulation, Inducing the Clearance and Degradation of FXIa (Activated Factor XI).

Objective- Activation of coagulation FXI (factor XI) by FXIIa (activated factor XII) is a prothrombotic process. The endothelium is known to play an antithrombotic role by limiting thrombin generation and platelet activation. It is unknown whether the antithrombotic role of the endothelium includes sequestration of FXIa (activated factor XI) activity. This study aims to determine the role of endothelial cells (ECs) in the regulation of the intrinsic pathway of coagulation. Approach and Results- Using a chromogenic assay, we observed that human umbilical veins ECs selectively blocked FXIa yet supported kallikrein and FXIIa activity. Western blotting and mass spectrometry analyses revealed that FXIa formed a complex with endothelial PAI-1 (plasminogen activator inhibitor-1). Blocking endothelial PAI-1 increased the cleavage of a chromogenic substrate by FXIa and the capacity of FXIa to promote fibrin formation in plasma. Western blot and immunofluorescence analyses showed that FXIa-PAI-1 complexes were either released into the media or trafficked to the early and late endosomes and lysosomes of ECs. When baboons were challenged with Staphylococcus aureus to induce a prothrombotic phenotype, an increase in circulating FXIa-PAI-1 complex levels was detected by ELISA within 2 to 8 hours postchallenge. Conclusions- PAI-1 forms a complex with FXIa on ECs, blocking its activity and inducing the clearance and degradation of FXIa. Circulating FXIa-PAI-1 complexes were detected in a baboon model of S. aureus sepsis. Although ECs support kallikrein and FXIIa activity, inhibition of FXIa by ECs may promote the clearance of intravascular FXIa. Visual Overview- An online visual overview is available for this article.

Lipid levels and selected biomarkers of vascular changes in children with idiopathic headaches - a preliminary report.

IntroductionElevated lipid concentrations were observed in adults with headaches. However, studies in children are scarce. Recent data suggest new potential risk factors for atherosclerosis, which may be associated with headaches. The aim of the study was to analyse the blood levels of lipids and new markers of atherosclerosis in children with idiopathic headaches.Material and methodsThe study population comprised 65 children (39 with idiopathic headaches and 26 healthy children). Total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL) cholesterol and triacylglycerol (TG) levels were measured in every patient. Brain-derived neurotrophic factor (BDNF), soluble CD40 ligand (sCD40L), endothelial plasminogen activator inhibitor (serpin E1/PAI I) and vascular endothelial growth factor (VEGF) blood level measurements were performed in 34 children.ResultsChildren with headaches had higher BMI z-scores (0.2 vs. –1.14; p = 0.006). TC level was lower in patients with headaches (121.04 mg/dl vs. 146.87 mg/dl, p = 0.019). No differences in concentrations of TG, HDL or LDL were found. BDNF was significantly higher in the studied group (171.57 pg/ml vs. 64.04 pg/ml, p = 0.012). The VEGF was higher in boys with headaches than in girls (368.27 pg/ml vs. 142.86 pg/ml, p = 0.011). There were no differences in levels of VEGF, sCD40L or PAI-1 between groups.ConclusionsChildren with headaches have lower total cholesterol and higher BDNF levels than controls. No significant difference in levels of triacylglycerols, HDL cholesterol, LDL cholesterol, VEGF, sCD40L or PAI-1 was found between children with headaches and controls.

Association Between - 675 ID, 4G/5G PAI-1 Gene Polymorphism and Pregnancy Loss: A Systematic Review

Introduction:Several analysis for different population conclude that endothelial plasminogen activator inhibitor 1 gene polymorphism, -675 ID, 4G/5G PAI-1 (ref SNP ID: rs1799889, also described as rs34857375, has merged into rs1799762) may increase risk of pregnancy loss (PL). However, there is a disagreement as to the association 4G allele with pregnancy loss.Aim:Therefore, we decided to investigate the -675 ID, 4G/5G PAI-1 as a potential genetic factor linked to PL in European and worldwide populations. A systematic review of the scientific literature was conducted with the use of the PubMed and Scopus electronic databases (1991-present), using the following search terms: pregnancy loss, miscarriage, genetic risk of thrombophilia, rs1799889 PAI-1 gen, 4G/5G PAI-1 gene polymorphism, PAI-1 gene locus 4G/5G polymorphism.Results:Among European populations, the statistically significant association between 4G allele and recurrent PL only in Czechs and Bulgarian women was found (p<0.002 and p=0.018, respectively); while, among populations outside Europe in Iranian, Tunisian and Turkish women (each p<0.001).Conclusions:We concluded, that both in Europe and elsewhere in the world, the high frequency of 4G allele in population, is not unambiguously linked with the risk of pregnancy loss.

Sitagliptin ameliorates vascular endothelial function in newly diagnosed type 2 diabetes patients

Objective To investigate sitagliptin and repaglinide could ameliorate endothelial function in newly diagnosed type 2 diabetes patients and to explore its mechanism. Methods A total of 92 newly diagnosed type 2 diabetes patients with glycated hemoglobin A1c (HbA1c) from 6.5% to 8.5% was randomly assigned to sitagliptin group(n=46)receiving sitagliptin, and repaglinide group (n=46) receiving repaglinide for 12 weeks. The effect of sitagliptin on vascular endothelial function was measured with endothelium-dependent flow-mediated vasodilation (FMD). FMD, level of serum nitric oxide (NO), plasminogen activator inhibitor-1 (PAI-1) and biochemical variables in the two groups were measured at baseline and 12 weeks after treatment. Results Fasting blood glucose (FBG), postprandial blood glucose (PBG), and HbA1c decreased significantly both in sitagliptin and repaglinide groups after treatment, but the descent more significantly in the repaglinide group than those in the sitagliptin group (P<0.05). FMD, NO, and homeostasis model assessment-β (HOMA-β) were increased, and PAI-1 and homeostasis model assessment-insulin resistance (HOMR-IR) decreased in both two groups of patients (P<0.05). FMD, NO, and PAI- 1 improved more significantly in sitagliptin groups (P<0.05). With FMD as dependent variables, multiple linear regression analysis showed that NO was a major protection factors of endothelial function, and PAI-1 and mean artery pressure (MAP) were major injury factors of endothelial function. Furthermore, with △FMD as the dependent variable, FMD as the dependent variable, and body mass index (BMI), MAP, HbA1c, HOMA-IR, triglycerides (TG), NO, and PAI-1 as a covariate-linear analysis of covariance showed that improved FMD with NO and PAI-1 were still relevant after treatment with sitagliptin. Conclusions Sitagliptin could improve vascular endothelial function evaluated by FMD better than repaglinide in newly diagnosed type 2 diabetes, the partial mechanism was related to the increase of NO level and the decrease of PAI-1 level, and the effect may be independent of the hypoglycemic effect. Key words: Dipeptidyl-peptidase IV inhibitors/TU; Carbamates/TU; Diabetes mellitus, type 2/DT; Endothelium, vascular/DE

Evaluation of Endothelial Damage in Sinusoidal Obstructive Syndrome

Introduction: Sinusoidal Obstructive Syndrome (SOS) is a complication derived from the endothelial damage associated to hematopoietic stem-cell transplant (HSCT) conditioning. Although its appearance is highly dependent on patient risk factors, it has an estimated prevalence of 14% and is associated with a high morbidity and with mortality rates than can ascend to 90% at day +100 of transplant in severe cases. New methods to early diagnose SOS are needed in order to minimize the incidence and severity of SOS.Here we present preliminary results of our single center prospective study that aims to measure and validate a panel of biomarkers in plasma [L-Ficolin, hyaluronic acid (HA), vascular adhesion molecule-1 (VCAM1) and plasminogen activator inhibitor-1 (PAI-1)] which have been recently described to be prognostic of the development of SOS (Akil et al, Biol. Blood Marrow Transplant. 21, 1739-1745, 2015).Methods: Twenty-one adult patients undergoing HSCT were recruited (median age 43.5 years old, 20-68), 15 men and 6 women. Three patients (14%) were diagnosed of SOS and received defibrotide (Gentium/Jazz Pharmaceutical) treatment. Diagnosis of SOS was performed based on the Seattle and Baltimore modified Criteria.Citrated blood samples from all patients were obtained before starting conditioning regimen (V0), and at infusion day (V1), 7 (V2) and 14 (V3) after infusion. Three additional samples (V4, V5 and V6) were drawn from those patients with SOS (just before defibrotide and 7 and 14 days after treatment with defibrotide). Samples were centrifuged twice at 23°C (15 min at 1,500 g, and 2 min at 13,000 g) and aliquots were stored at -80ºC until analysis.Phosphatidylserine-MP (Ph-MP) and tissue factor-MP (TF-MP) dependent procoagulant activities were determined with the ZYMUPHEN kits. VCAM1, PAI-1, L-Ficolin and HA concentrations were measured by ELISA.Data from the routine laboratory analysis were also registered.Statistical analyses was performed with SPSS software. Values of p≤0.05 were considered statistically significant.Results : Considering transplant type, 9 were autologous and 9 allogenic in controls, and 3 allogenic in SOS; donor type were 3 unrelated, 6 related and 3 haploidentical in controls, and 3 related and 2 haploidentical in SOS. Conditioning regimen intensity was 7 full, 2 reduced, 8 with busulfan and 1 with total body irradiation in controls and 3 reduced and 2 with busulfan in SOS group. Controls received 2(1-4) previous chemotherapy lines whereas SOS group received 3(2-9).Regarding diseases, 4 presented acute myeloblastic leukemia, 2 acute lymphoblastic leukemia, 3 multiple myeloma, 3 non-Hodgkin's lymphoma and 6 Hodgkin's disease in control group whereas in SOS group 1 had acute myeloblastic leukemia, 1 myelodysplastic syndrome and 1 non-Hodgkin's lymphoma.As observed, occurrence of SOS did not seem to be related to either the malignant disease or number of chemotherapy drugs employed for its treatment or donor type and conditioning regimen.L-Ficolin, a complement activator involved in homeostatic clearance of mitochondria in the liver, seemed to diminished in the SOS group at V3 (wo SOS : 1025±923 ng/mL ; SOS : 680±817 ng/mL). Nevertheless, this diminution was not significant probably due to the few patients with SOS.No differences were observed between patients without and with SOS in plasma levels of markers of endothelial damage VCAM1, PAI-1 and HA, this last a direct indicator of hepatic sinusoidal endothelial cell function.Procoagulant activity associated to Ph-MP was lower in patients with SOS (p=0.023) whereas that associated to TF-MP was unaffected.Plasma levels of VCAM1 and HA increased along time in both groups. After treatment with defibrotide these values achieved steady levels in SOS patients (V4 and V5). On the other hand, PAI-1 did not change over time.SOS patients presented at V3 higher total bilirrubin (wo SOS: 0.86±0.53 mg/dL; SOS: 2.31±0.18 mg/dL, p=0.008) and lower albumin levels (wo SOS: 3.5±0.3 g/dL; SOS: 2.7±0.1 g/dL)Conclusions: Our results indicate that endothelial damage is present in all patients undergoing HSCT and that treatment of SOS patients with defibrotide might restrain this injury. Due to the low number of patients included so far, we cannot conclude anything about the value of biomarkers proposed to serve as predictors of SOS onset. Our study is still open and recruiting patients.This work was supported by Jazz Pharmaceutical DisclosuresNo relevant conflicts of interest to declare.

Effects of omega-3 polyunsaturated fatty acids administration on vascular function, inflammatory and fibrinolytic status in adults with metabolic syndrome

Purpose: Metabolic syndrome (MetS) is associated with impaired vascular function. Aim of the present study was to evaluate the effects of omega-3 polyunsaturated fatty acids (PUFAs) supplementation on endothelial function, arterial stiffness, inflammatory and fibrinolytic process in subjects with MetS. Methods: We studied the effect of a 12 weeks oral treatment with 2gr/day of omega-3 PUFAs in 29 (15 male) subjects (mean age 44±12 years) with MetS on three occasions (day 0: baseline, day 28 and day 84). The study was carried out on two separate arms (PUFAs and placebo), according to a randomized, placebo-controlled, double-blind, cross-over design. The diagnosis of MetS was based on the guidelines of Adult Treatment Panel III definition. Endothelial function was evaluated by flow-mediated dilation (FMD) of the brachial artery. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness. Serum levels of interleukin-6 (IL-6) and plasminogen activator inhibitor-1 (PAI-1) were measured by ELISA. Fasting serum lipid levels were measured using chromatographic enzymic method. Results: Treatment with PUFAs resulted in a significant increase in FMD and PWV (p<0.001 for both). Nevertheless, treatment with placebo resulted in no significant changes in FMD and PWV (p=NS for all). Moreover, PUFAs treatment, compared to placebo, decreased IL-6 levels and increased PAI-1 levels (p<0.001 for both). Finally, PUFAs decreased fasting serum triglyceride levels, total cholesterol levels and low density lipoprotein cholesterol levels (p<0.001 for all). View this table: Table 1. Effects of PUFAs on endothelial function, arterial stiffness, IL-6, PAI-1 and lipids levels Conclusions: Treatment with omega-3 PUFAs favorably affect endothelial function and the elastic properties of the arterial tree in MetS subjects, with a parallel antiinflammatory effect.

Estrogen regulates endothelial migration via plasminogen activator inhibitor (PAI-1)

Endothelial plasminogen activator inhibitor (PAI-1) controls vascular remodeling, angiogenesis and fibrinolysis. PAI-1 blood levels in women are related to estrogen. The aim of this study was to characterize the signaling pathways through which estrogen regulates PAI-1 in endothelial cells. Furthermore, we aimed to investigate whether PAI-1 is implicated in the control of endothelial migration by estrogen. Cultured human umbilical vein endothelial cells (HUVECs) and ovariectomized rats were used to test the effects of 17β-estradiol (E(2)) on PAI-1 expression and its role on endothelial migration. At physiological concentrations, E(2) increases the expression of PAI-1 in HUVEC within 6-12 h through activation of a signaling cascade initiated by estrogen receptor α and involving G proteins, phosphatidylinositol-3-OH kinase and Rho-associated kinase II. ROCK-II activation turns into an over-expression of c-Jun and c-Fos that is required for E(2)-induced expression of PAI-1. Estrogen-induced PAI-1 expression is implicated in HUVEC horizontal migration. PAI-1 regulation is found also in vivo, in female rats, where ovariectomy is associated with reduced PAI-1 expression, while estrogen replacement counteracts this change. In conclusion, E(2) increases PAI-1 synthesis in human endothelial cells and in rodent aorta through a G protein-initiated signaling that targets early-immediate gene expression. This regulatory pathway is implicated in endothelial cell migration. These findings describe new mechanisms of action of estrogens in the vessels, which may be important for vascular remodeling and hemostasis.

Letter to the Editor Obstructive sleep apnoea syndrome and cardiovascular risk

Zamarron et al. [1] report that obstructive sleep apnoea syndrome (OSAS) is associated with raised levels of markers of endothelial function. Moreover, some of these markers (intercellular cell adhesion molecule-1 (ICAM-1) and plasminogen activator inhibitor-1 (PAI-1)) improved after nasal continuous positive airway pressure [1]. Some additional comments may be of interest. Metabolic syndrome (MetS) is highly prevalent in patients with OSAS [2]. In turn, intermittent hypoxia increases insulin resistance [2]. Consequently, it is difficult to identify the contribution of OSAS and MetS to vascular risk, since they share common predisposing factors (e.g. obesity [2] and endothelial dysfunction [3]). Markers of endothelial activation, including ICAM-1, PAI-1 and E-selectin, are raised in MetS [3] and Zamarron et al. [1] report a similar pattern in OSAS. Platelet activation occurs in MetS due to reduced availability of endothelium-derived nitric oxide (NO) and prostacyclin [4]. Similarly, in OSAS a decrease in NO availability and prostacyclin/thromboxane metabolite ratio has been reported [2, 5]. Markers of platelet activation, including mean platelet volume (MPV) and platelet distribution width (PDW), were increased in OSAS, in parallel with the severity of hypoxia [6]. Therefore, it would be helpful to know how many patients in the control and OSAS group had MetS in the Zamarron et al. [1] study. Taken together, all these findings highlight the role of OSAS on endothelial integrity and as a contributor to cardiovascular risk.

P38 Mitogen-Activated Protein Kinase Is Required for Glucosamine-Induced Endothelial Nitric Oxide Synthase Uncoupling and Plasminogen-Activator Inhibitor Expression

Hexosamine biosynthetic pathway (HBP) is implicated in increased plasminogen activator inhibitor-1 (PAI-1), and endothelial nitric oxide synthase (eNOS) dysfunction in diabetes. Glucosamine (GlcN) that directly activates HBP is a dietary supplement and is clinically used to treat osteoarthritis despite uncertain efficacy and adverse cardiovascular effects observed in animal models. p38 mitogen-activated protein kinase (p38mapk) has been shown to be involved in HBP-mediated biological processes. The aim of the present study was to investigate the role of p38mapk in GlcN-induced endothelial PAI-1 expression and eNOS dysfunction. In cultured human endothelial cells, GlcN time- and concentration-dependently increased PAI-1 protein level that was further enhanced by tumor necrosis factor (TNF)-α, which was accompanied by a transient synergistic activation of p38mapk. The stimulation of PAI-1 by GlcN alone or by GlcN and TNF-α in combination was inhibited by the specific inhibitor of p38mapk, but not that of JNK or ERK1/2. Moreover, in isolated mouse aortas, GlcN caused eNOS uncoupling resulting in enhanced superoxide and decreased NO production, as well as impaired endothelium-dependent relaxations, which were also fully prevented by the p38mapk inhibitor. HBP activated by GlcN increases PAI-1 expression and eNOS uncoupling depending on p38mapk, which not only explains hyperglycemic vascular complications, but also may bring into question the clinical use of GlcN. The present results, support currently ongoing clinical application of p38mapk inhibitor in patients with cardiovascular disease.

Cardiovascular protective effects of nebivolol in Zucker diabetic fatty rats

Although effective in reducing blood pressure, therapy with a first-generation [beta]-blocker is currently controversial in metabolic syndrome due to its negative impact on carbohydrate and lipid metabolism. We evaluated the effects of nebivolol, a third-generation highly selective [beta]-blocker with additional vasodilating activity, versus the traditional [beta]-blocker atenolol in controlling functional and morphological cardiovascular damage in a rat model of metabolic syndrome. During 6 months, Zucker diabetic fatty (ZDF) rats and control lean Zucker rats (LZR) were studied. The experimental groups were: untreated ZDF, ZDF along with nebivolol, ZDF along with atenolol and LZR. Blood pressure, plasma insulin, triglycerides, cholesterol, glucose and platelet aggregation were evaluated. Malondialdehyde, reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, CuZn superoxide dismutase, catalase and glutathione peroxidase were determined in heart homogenates and transforming growth factor [beta]1 and plasminogen activator inhibitor-1 (PAI-1) expression, by immunohistochemistry (IHC). Vascular reactivity, vascular cell adhesion molecule-1, platelet endothelial cell adhesion molecule-1, PAI-1, enhanced nitric oxide synthase and collagen expression were evaluated in aorta. Nebivolol and atenolol presented a similar reduction in blood pressure. However, nebivolol showed a better lipid profile, preserved left ventricular function, a significant control in left ventricular geometry and moderated left ventricular hypertrophy versus atenolol. Significant reduction in platelet aggregation and a substantial endothelium-dependent and endothelium-independent relaxation in vessels were also shown in the nebivolol group versus atenolol group. Antioxidant defenses were preserved by nebivolol with a reduction in oxidative stress parameters. Vascular cell adhesion molecule-1, platelet endothelial cell adhesion molecule-1, PAI-1 and eNOS were favorably modulated with nebivolol in vessel wall. TGF[beta]1, PAI-1 and accumulation of collagen-III and collagen-I were also diminished in heart with nebivolol. The present study provides substantial information supporting an actual protective role of nebivolol in comparison with atenolol in experimental metabolic syndrome.

Protective Effects of Ginsenoside Rb1 on Human Umbilical Vein Endothelial Cells In Vitro

Ginseng has beneficial effects on the cardiovascular system, but its underlying mechanism is unclear. This study investigated the effects of ginsenoside Rb1, a major constituent of ginseng, on the changes of lactate dehydrogenase (LDH) activity, nitric oxide (NO), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) in oxidized low-density lipoprotein (oxLDL)-injuring endothelial cells. Human umbilical vein endothelial cells were cultured and divided into 6 groups (n = 6): control group, oxLDL alone group (100 mg/L), ginsenoside Rb1 alone group (10 microg/mL), oxLDL plus ginsenoside Rb1 groups (0.1, 1.0, and 10 microg/mL, respectively.). Twenty-four hours after treatment, LDH activity and concentrations of NO, t-PA, and PAI-1 in culture medium were measured while the expressions of endothelial nitric oxide synthase (eNOS), t-PA, and PAI-1 mRNA in endothelial cells were detected by reverse-transcriptase polymerase chain reaction. Compared with control group, oxLDL (100 mg/L) caused LDH activity, the expressions of eNOS and t-PA mRNA, and concentrations of NO and t-PA to significantly decrease (P < 0.05, respectively), and it also led to dramatic increase of PAI-1 mRNA and concentration (P < 0.05, respectively). Ginsenoside Rb1 alone did not demonstrate this ability. High-dose Rb1 (10 microg/mL) could block the effects of oxLDL on LDH activity, mRNA of eNOS, t-PA, and PAI-1, and concentrations of NO, t-PA, and PAI-1 (P < 0.05, respectively), and neither low-dose Rb1 (0.1 microg/mL) nor medium-dose Rb1 (1.0 microg/mL) demonstrated this ability. We conclude that ginsenoside Rb1 has protective effects on oxLDL-injuring human vascular endothelial cells and can reverse the effects of oxLDL on NO, t-PA, and PAI-1.

Platelets, thrombospondin-1 and human dermal fibroblasts cooperate for stimulation of endothelial cell tubulogenesis through VEGF and PAI-1 regulation

During cutaneous wound repair, platelets, dermal fibroblasts (DF) and endothelial cells all cooperate. We have presently investigated the regulation of endothelial cell tubulogenesis by human platelet thrombospondin-1 (TSP-1), in comparison to transforming growth factor-β1 (TGF-β1) and total platelet lysates (PL), in a fibrin matrix cell culture system incorporating DF. TSP-1, TGF-β1 and PL all stimulated VEGF expression in DF dose dependently at mRNA and protein level. TSP-1- and PL-treated DF supernatants significantly stimulated capillary-like structure formation (tubulogenesis) by dermal microvascular endothelial cells (HMEC-1 and HDMEC), in part via VEGF, as confirmed with neutralizing anti-VEGF antibodies. In contrast, TGF-β1-treated DF supernatants did not induce tubulogenesis. This apparent discrepancy could be explained by the differential expression regulation in HMEC-1 of fibrinolysis and metalloproteinase mediators by TSP-1 and TGF-β1. TSP-1 potently reduced the expression of plasminogen activator inhibitor-1 (PAI-1) (mRNA and protein), whereas TGF-β1 enhanced it. The crucial role of PAI-1 in tubulogenesis was confirmed via the addition of active recombinant PAI-1, which abrogated tubulogenesis. In contrast, neutralizing PAI-1 antibodies enhanced tubulogenesis. Our results suggest that platelet TSP-1 released in a wound stimulates endothelial cell tubulogenesis through an upregulation of DF VEGF expression and a downregulation of endothelial cell PAI-1 expression.

Hemostasis and Glycemic Control in the Cardiac Surgical Patient

The Centers for Disease Control and Prevention estimate that 6% of the US population meets diagnostic criteria for diabetes mellitus, with at least one third of this group being undiagnosed. A majority of adult blindness, renal insufficiency, and limb amputation may be directly attributed to diabetes. Although the incidence of type 1, autoimmune-mediated diabetes remains relatively stable, increasing age, physical inactivity, and obesity have produced explosive growth in insulin resistance and type 2 diabetes. A direct association between diabetes and atherothrombotic disease remains indisputable. However, recent data further suggest that even minor elevations of fasting plasma glucose, in "nondiabetic" subjects, increase cardiovascular risk. Alterations in hemostasis may play an important contributory role. Both hyperglycemia and hyperinsulinemia induce prothrombotic characteristics, including overexpression of vascular endothelial plasminogen activator inhibitor-1 (PAI-1), down-regulation of fibrinolysis, elevation of plasma coagulation proteins (ie, fibrinogen, factor VII, factor X), and enhanced platelet activation. Furthermore, endothelial dysfunction-characterized by an inflammatory phenotype-commonly accompanies diabetes. Given data supporting prothrombotic potential of both acute and chronic hyperglycemia, aggressive perioperative glucose control appears imperative.

Glycation Does Not Alter LDL‐Induced Secretion of Tissue Plasminogen Activator and Plasminogen Activator Inhibitor‐1 from Human Aortic Endothelial Cells

Diabetes may induce both quantitative and qualitative changes in lipoproteins, especially low-density lipoprotein (LDL). Effects of LDL glycation on endothelial cell secretion of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) have not been fully elucidated. Human aortic endothelial cell (HAEC) tPA and PAI-1 production were determined after incubation with LDL (50 to 500 microg/mL protein, 24 h) from three sources: (1) nondiabetic LDL (N-LDL) modified in vitro to form six preparations: native, nonmodified (N); glycated (G); minimally oxidized (MO); minimally oxidized and glycated (MOG); heavily oxidized (HO); and heavily oxidized and glycated (HOG); (2) in vivo glycated and relatively nonglycated LDL subfractions from type 1 diabetic patients; (3) LDL from type 1 diabetic patients and matched controls, which was subfractionated using density gradient ultracentrifugation. In experiments using LDL modified in vitro, the rate of tPA release by HAECs incubated with N-LDL (83 +/- 4 ng/mg cell protein/24 h) did not differ significantly from those incubated with G-LDL (73 +/- 7), MO-LDL (74 +/- 13), or MOG-LDL (66 +/- 15) and was not influenced by LDL concentration. The rate of PAI-1 release was similar in HAECs incubated with N-LDL (5.7 +/- 0.6 mug/mg cell protein/24 h), G-LDL (5.7 +/- 0.7), MO-LDL (5.5 +/- 0.8), or MOG-LDL (5.7 +/- 0.9) and was not influenced by LDL concentration. In contrast, tPA release was significantly decreased in cells incubated with LDL (10 microg/mL) modified extensively by oxidation, and averaged 45.2 +/- 5.0 and 43.7 +/- 9.9 ng/mg/24 h for HO-LDL and HOG-LDL, respectively, and was further decreased with increasing concentrations of the heavily oxidized LDL preparations. PAI-1 release was not significantly decreased relative to N-LDL in cells incubated with low concentrations (5 to 50 microg/mL) of HO-LDL and HOG-LDL, but was decreased to 3.2 +/- 0.5 and 3.1 +/- 0.7 microg/mg/24 h for HO-LDL and HOG-LDL at 200 microg/mL, respectively. Results using in vivo glycated versus nonglycated LDL showed that tPA and PAI-1 release did not differ between subfractions. Release of tPA averaged 5.11 +/- 0.6 and 5.12 +/- 0.7 ng/mg/24 h, whereas release of PAI-1 averaged 666 +/- 27 ng/mg/24 h and 705 +/- 30 ng/mg/24 h for nonglycated and glycated LDL subfractions, respectively. Using LDL of different density subclasses, tPA and PAI-1 release in response to LDL from diabetic patients compared with control subjects did not differ when HAECs were incubated with LDLs of increasing density isolated from each subject pair. We conclude that oxidation of LDL, but not glycation, may contribute to the altered fibrinolysis observed in diabetes.

C-type natriuretic peptide (CNP) suppresses plasminogen activator inhibitor-1 (PAI-1) in vivo

Elevated vascular plasminogen activator inhibitor-1 (PAI-1) levels are associated with atherosclerosis. In vitro, C-type natriuretic peptide (CNP) has anti-proliferative effects and inhibits the production of PAI-1 in cultured vascular cells. Whether CNP can affect PAI-1 in vivo, particularly in the setting of atherosclerosis, has not been reported. Using the rabbit carotid arterial collar model of intimal hyperplasia (collar in place for 7 days), PAI-1 protein was compared in normal, vehicle (saline)-collared, and CNP-treated-collared arteries from the same animal. PAI-1 levels were measured by immunohistochemistry and densitometry and by Western blot. CNP was either infused into the peri-arterial space within one collar (10 fmol/h) or infused directly into the arterial lumen under one collar (100 pmol/h). In some rabbits (n=8), superoxide production in collared and normal artery segments was measured in vitro by chemiluminescence. PAI-1 was present throughout the vascular wall. Endothelial PAI-1 was elevated in saline-collared arteries (approximately 16%, P<0.05; n=7 rabbits) compared with normal carotid segments. The collar induced both a neointima that contained PAI-1 and the accumulation of macrophages in the adventitia. Peri-arterial CNP reduced PAI-1 (P<0.05) in the endothelium (33%), adventitia (47%) and neointima (39%), compared with levels in the contralateral, saline-collared carotid artery, while macrophage infiltration was reduced. Elevated superoxide production in collared arteries was not altered by chronic in vivo treatment with CNP (n=8). Peri-arterial CNP treatment did not reduce intimal thickening. Intra-luminal CNP (n=6) reduced endothelial, neointimal and total vessel (Western blot) PAI-1, macrophage accumulation, and intimal thickening (all P<0.05). CNP treatment of collared carotid arteries in vivo for 1 week suppressed endothelial and neointimal PAI-1, independently of intimal thickening. The CNP effects were not via superoxide. This is the first evidence that CNP inhibits activated PAI-1, in vivo.