Markers Of Vascular Activation Research Articles

Epeleuton, a novel synthetic ω-3 fatty acid, reduces hypoxia/ reperfusion stress in a mouse model of sickle cell disease.

Inflammatory vasculopathy is critical in sickle cell disease (SCD)-associated organ damage. An imbalance between pro-inflammatory and pro-resolving mechanisms in response to different triggers such as hypoxia/reoxygenation or infections has been proposed to contribute to the progression of SCD. Administration of specialized pro-resolving lipid mediators may provide an effective therapeutic strategy to target inflammatory vasculopathy and to modulate inflammatory response. Epeleuton (15 hydroxy eicosapentaenoic acid ethyl ester) is a novel, orally administered, second-generation ω-3 fatty acid with a favorable clinical safety profile. In this study we show that epeleuton re-programs the lipidomic pattern of target organs for SCD towards a pro-resolving pattern. This protects against systemic and local inflammatory responses and improves red cell features, resulting in reduced hemolysis and sickling compared with that in vehicle-treated SCD mice. In addition, epeleuton prevents hypoxia/reoxygenation-induced activation of nuclear factor-κB with downregulation of the NLRP3 inflammasome in lung, kidney, and liver. This was associated with downregulation of markers of vascular activation in epeleuton-treated SCD mice when compared to vehicle-treated animals. Collectively our data support the potential therapeutic utility of epeleuton and provide the rationale for the design of clinical trials to evaluate the efficacy of epeleuton in patients with SCD.

In Vivo Profiling of the Vascular Cell Surface Proteome in Murine Models of Bacteremia.

Vascular dysfunction is a hallmark of systemic inflammatory responses such as bacterial sepsis. The luminal surface of the blood vessels is coated with a dense layer of glycans and proteoglycans, collectively known as the glycocalyx. Surface associated glycoproteins of endothelial origin, or derived from pericytes, intravascular leukocytes, and plasma, are other important components of the glycocalyx, constituting a vascular cell surface proteome that is dynamic, tissue-specific, and sensitive to changes in vascular homeostasis, blood infection, and inflammation. Here, we describe an experimental protocol to chemically tag and quantify the vascular cell surface proteome in murine models of bacteremia, in a time-resolved and organ-specific manner. This method facilitates the identification of markers of vascular activation and provides a molecular framework to understand the contribution of vascular dysfunction to the organ pathology of systemic inflammation.

Circulating Biomarkers in Migraine: New Opportunities for Precision Medicine.

Migraine is the most common neurological disorder and the second most disabling human condition, whose pathogenesis is favored by a combination of genetic, epigenetic, and environmental factors. In recent years, several efforts have been made to identify reliable biomarker(s) useful to monitor disease activity and/or ascertain the response to a specific treatment. To review the current evidence on the potential biological markers associated with migraine. A structured search of peer-reviewed research literature was performed by searching major publications databases up to December 2017. Several circulating biomarkers have been proposed as diagnostic or therapeutic tools in migraine, mostly related to migraine's inflammatory pathophysiological aspects. Nonetheless, their detection is still a challenge for the scientific community, reflecting, at least in part, disease complexity and clinical diagnostic limitations. At the present time, calcitonin generelated peptide (CGRP) represents probably the most promising candidate as a diagnostic and/or therapeutic biomarker, as its plasma levels are elevated during migraine attack and decrease during successful treatment. Other molecules (including some neuropeptides, cytokines, adipokines, or vascular activation markers) despite promising, do not possess the sufficient prerequisites to be considered as migraine biomarkers. The characterization of migraine-specific biomarkers would be fundamental in a perspective of precision medicine, enabling risk assessment and tailored treatments. However, speculating on the clinical validity of migraine biomarkers may be premature and controlled clinical trials are presently needed to investigate both the diagnostic and therapeutic value of these biomarkers in migraine.

Vitamin D and Inflammatory Markers in Children with Sickle Cell Disease

Background: Vitamin D, in addition to its role in calcium and bone homeostasis, is a multifunctional regulator of inflammation and of innate and adaptive immune responses. Deficiencies are prevalent in sickle cell disease. We conducted a randomized double- blind active-controlled clinical trial comparing high- (100,000 IU/month) and low-dose (12,000 IU/month) oral vitamin D3 in 62 children with sickle cell disease to reduce respiratory complications including infection, asthma exacerbation and acute chest syndrome (ViDAS trial: Vitamin D for sickle cell respiratory complications; NCT01443728). A secondary aim was to examine the effects of vitamin D on immune function and inflammation. Methods: Using stored serum samples collected from subjects at steady state, we examined hsCRP (single-plex assay) and key cytokines and markers of vascular activation (20-plex immunoassay) at baseline and year-1 in a subset of 36 subjects with HbSS (high-dose: n=17; low-dose: n=19), mean age 7.8 years, 53% females and 67% on hydroxyurea. Immune markers included IL1β, IL1RA, IL2, IL4, IL10, IL18, IL22, IFNγ, TNFα, TNFβ, sFasL, CXCL1, CXCL8 (IL8), PDGFBB, VEGFA, serpin E1 (PAI1), sICAM1, VCAM1, TGFα and TGFβ. Raw immune data were transformed using Box-Cox transformations and standardized; markers with persistently skewed (non-Gaussian) distributions after transformation were dichotomized for analysis. Continuous immune variables were analyzed by repeated measures ANOVA (unadjusted) and ANCOVA (adjusted for baseline covariates of age, sex and baseline total 25-hydroxyvitamin D3 and D2). Dichotomized biomarkers were analyzed using generalized linear mixed-effects models. Secondary analyses stratified on hydroxyurea status were also pursued. For these exploratory biomarker discovery-focused analyses, all significance tests were performed 2-tailed without adjustment for multiple comparisons, with α=0.1 for main effects and 0.2 for interactions. Results: Independent of vitamin D3 dose, serum concentrations of immune markers declined from baseline to the 1-year timepoint for the pro-inflammatory markers IL2, CXCL8 (IL8), IFNγ, TGFα, CXCL1 and PDGFBB and the counter-regulatory molecule, IL10. Among all subjects, interactions of dose group*time were found for IL2, sICAM1 and hsCRP; subjects on hydroxyurea additionally demonstrated dose group*time interactions for serpin E1 (PAI1), IFNγ and TNFα. Subjects on hydroxyurea in the high-dose group also demonstrated decreases over 1-year follow-up in serum IL2, serpin E1, IFNγ, TNFα, sICAM1 and hsCRP whereas serum levels of these immune markers increased among subjects in the low-dose group taking hydroxyurea. This crossover pattern in direction of the dose group*time interaction effect was also observed for the larger study population for sICAM1 and hsCRP. Table 1 shows the markers that tested significantly for main effects and/or interactions. Effects for the rest of the markers were not statistically significant. Conclusions: Our data support the immunomodulatory properties of vitamin D, with variable responses to high and low doses. Effects involved several salient immune and vascular markers for sickle cell disease, including IL2, serpin E1, IFNγ, TNFα, sICAM1 and hsCRP, and appeared to be more pronounced among subjects on high-dose vitamin D3 who were also taking hydroxyurea. Table 1 Disclosures Brittenham: Nestec, Inc.: Consultancy; Novartis International: Consultancy; Tesseract Health, Inc.: Consultancy; Vifor Fresenius Medical Care: Consultancy; Ambys Medicines: Consultancy; Dispersol Technologies: Consultancy; Rockwell Medical, Inc.: Consultancy.

Association between Inflammatory Markers and Abnormal Neurological, Neurocognitive and Magnetic Resonance Imaging (MRI) Findings in Children with Sickle Cell Anemia in Uganda

Background: Children with sickle cell anemia (SCA) are highly susceptible to stroke and other manifestations of pediatric cerebral vasculopathy. Inflammation is a risk factor for acute stroke. In a cross-sectional study of Ugandan children, we asked whether inflammatory markers correlated with findings on neurological and neurocognitive testing and magnetic resonance imaging (MRI). Methods: Stored plasma samples were obtained at a well study visit from 81 children, a subset within a larger sample of study participants with HbSS ages 1-12 years recruited at the Mulago Hospital sickle cell clinic in Kampala. Participants underwent 4 standardized assessments: neurocognitive testing using the Mullen Scales of Early Learning (for ages 1-4 years) or Kaufman Assessment Battery for Children, 2nd edition (for ages 5-12) (abnormal at z-score of -2 or lower), examination for prior stroke (PedsNIHSS) and transcranial Doppler ultrasound (TCD) using criteria for pediatric SCA, plus a non-contrast MRI/MRA on a 1.5 Telsa scanner, analyzed for T1- and T2- weighted images and T2 FLAIR. MR scans were interpreted by clinical and research methods, the latter per SWiTCH protocol (Helton, Blood 2014). Adjudication of differing reads was performed by a blinded third neuroradiologist. Participants undergoing MRI intentionally included 29 without any abnormal findings on the three other evaluations. Plasma samples were examined for key cytokines and markers of vascular activation by a 20-plex Luminex immunoassay. Immune markers included IL1b, IL1RA, IL2, IL4, IL10, IL18, IL22, IFNg, TNFa, TNFb, sFasL, CXCL1, CXCL8 (IL8), PDGFBB, VEGFA, serpin E1 (Plasminogen Activator Inhibitor (PAI)-1), sICAM1, VCAM1, TGFa, plus assay of hsCRP. Raw immune data were transformed using Box-Cox transformations and standardized; markers with persistently skewed (non-Gaussian) distributions after transformation were dichotomized for analysis. Continuous immune variables were analyzed by repeated measures ANOVA (unadjusted) and ANCOVA (adjusted for baseline covariates of age, sex, hemoglobin and 25-hydroxy-vitamin D3/D2. Dichotomized biomarkers were analyzed using generalized linear mixed-effects models. For these exploratory biomarker discovery-focused analyses, all significance tests were performed 2-tailed without adjustment for multiple comparisons, with a=0.1 for main effects. Results: Mean age was 6.48 ± 2.75 years, 50.6% male. Mean hemoglobin was 7.26±0.90 g/dl; 16.7% were malnourished using standard international measures established for age and sex. Infarcts on MRI were detected in 42 (52%), including 13 (25%) with no other test abnormalities. Of the 20 inflammatory markers tested, the levels of 13 markers were associated with one or more abnormality. One or more infarcts on MRI as the sole abnormality ("silent" stroke) were associated with levels IL1b, IL2 and TGFb (Table 1). Neurocognitive dysfunction alone was associated only with levels of IL22. Abnormal TCD (primarily "conditional" values) or prior stroke was associated with levels of VEGFA, IL4 and TNFb. In contrast, abnormal TCD or stroke by examination plus neurocognitive dysfunction was associated with nine cytokines levels: CXCL8, CXCL1, IFNg, TNFa, sFasL, IL18, IL22, sICAM1 and VEGFA. In all cases, cytokine levels were negatively associated with each of the abnormal neurological, neurocognitive or imaging results. Adjusting for age, sex, hemoglobin and malnutrition had only modest effects on statistically significant results. No associations were found between the test results and any of the other eight inflammatory markers, including hsCRP. Conclusions: In this exploratory biomarker analysis in a sample with highly prevalent abnormal test results, the presence of those abnormalities correlated with levels of a majority of the inflammatory markers assayed. The clinically well status at sampling and the finding of lower markers levels associated with existing abnormalities suggest that these children were not currently inflamed. As a cross-sectional analysis, cerebral vasculopathy underlying those abnormalities had previously occurred. Lower levels of inflammation may reflect a survivor status of children affected by a chronic illness with high local mortality. Our findings need to be confirmed in a prospective study children, and may be most interesting at acute events and for subjects receiving disease-modifying therapy. Disclosures No relevant conflicts of interest to declare.

Resolution of sickle cell disease–associated inflammation and tissue damage with 17R-resolvin D1

AbstractResolvins (Rvs), endogenous lipid mediators, play a key role in the resolution of inflammation. Sickle cell disease (SCD), a genetic disorder of hemoglobin, is characterized by inflammatory and vaso-occlusive pathologies. We document altered proresolving events following hypoxia/reperfusion in humanized SCD mice. We demonstrate novel protective actions of 17R-resolvin D1 (17R-RvD1; 7S, 8R, 17R-trihydroxy-4Z, 9E, 11E, 13Z, 15E, 19Z-docosahexaenoic acid) in reducing ex vivo human SCD blood leukocyte recruitment by microvascular endothelial cells and in vivo neutrophil adhesion and transmigration. In SCD mice exposed to hypoxia/reoxygenation, oral administration of 17R-RvD1 reduces systemic/local inflammation and vascular dysfunction in lung and kidney. The mechanism of action of 17R-RvD1 involves (1) enhancement of SCD erythrocytes and polymorphonuclear leukocyte efferocytosis, (2) blunting of NF-κB activation, and (3) a reduction in inflammatory cytokines, vascular activation markers, and E-selectin expression. Thus, 17R-RvD1 might represent a new therapeutic strategy for the inflammatory vasculopathy of SCD.

Imatinib Protects Against Hypoxia/Reoxygenation Induced Lung and Kidney Injury in a Humanized Mouse Model for SCD

Sickle cell disease (SCD) is a worldwide distributed hereditary red cell disorder characterized by chronic hemolytic anemia in association with acute and chronic life-threatening complications mainly related to acute vaso-occlusive events (VOCs) due to amplified inflammatory response and defective pro-resolving events.Imatinib is an oral Tyrosine (Tyr)-kinase inhibitor, developed for the treatment of chronic myeloid leukemia (CML). Few case reports on SCD patients with CML undergoing imatinib treatment highlight the beneficial impact of imatinib on severity and recurrence of acute VOCs in SCD. In red blood cells (RBCs), Imatinib has been shown to interfere with Tyr-phosphorylation state of the integral membrane protein band 3, affecting RBC microparticle formation. Here, we study the actions of Imatinib on a model of acute VOCs using humanized SCD mice (Hbatm1(HBA)TowHbbtm2(HBG1,HBB*)Tow). We treated SCD and control healthy mice (AA, Hbatm1(HBA)Tow Hbbtm3(HBG1,HBB)Tow) (n=6-7 animals in each group) with Imatinib 50 mg/Kg/d for 2 weeks before hypoxia/Reoxygenation (H/R) stress used to mimic acute VOCs. Under normoxia, we found that in SCD mice Imatinib significantly reduced (i) Tyr-phosphorylation state of sickle red cell membrane proteins; (ii) the amount of phosphatidyl-serine (PS)+ sickle RBCs; and (iii) the release of erythroid microparticles, which was associated with accumulation of hemichromes and a more efficient erythrophagocytosis compared to vehicle treated animals. In SCD mice exposed to H/R stress, imatinib significantly decreased the H/R-induced (i) increase in peripheral neutrophil count; (ii) lung inflammatory cell infiltrate; (iii) kidney inflammatory cell infiltrate. In the lung of H/R SCD mice, Imatinib inhibited the H/R induced NF-kB activation and prevented the up-regulation of (i) pro-inflammatory cytokines such as ET-1; (ii) vascular endothelial activation markers (VCAM-1, ICAM-1); (iii) pro-fibrotic markers such as PDGF-B and (iv) the activation of UPR system. In the kidney of H/R SCD mice, Imatinib significantly reduced H/R induced expression of ET-1, VCAM-1 and E-selectin, which were again associated with inhibition of NF-kB. In addition, Imatinib significantly upregulated the expression of the microRNAs miR200a/b, which has been described to reduce renal fibrosis. Finally, in isolated aorta from Imatinib treated SCD exposed to H/R stress, a significant reduction in vascular activation markers was observed compared to vehicle treated animals. Collectively, our data indicate that Imatinib acts on multiple targets, modulating signal transduction and reducing inflammatory vasculopathy and extracellular matrix remodeling process related to VOC in SCD. Thus, Imatinib might represent a new therapeutic tool in clinical management of SCD patients. DisclosuresEl Nemer:Imara: Research Funding.

Clinical Implications

HomeHypertensionVol. 71, No. 1Clinical Implications Free AccessIn BriefPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessIn BriefPDF/EPUBClinical Implications Originally published1 Jan 2018https://doi.org/10.1161/HYPERTENSIONAHA.117.10603Hypertension. 2018;71:2Hypertensive Phenotypes After Preeclampsia (p 103)Download figureDownload PowerPointPreeclampsia is associated with a greater lifetime risk for cardiovascular and renal complications. International guidelines underline that women with hypertensive disorders of pregnancy should benefit from a postpartum screening and management of cardiovascular risk factors. However, specific recommendations, especially on the timing of the first medical visit and tests that need to be done, are still lacking. In this study, we performed ambulatory blood pressure monitoring 6 to 12 weeks after delivery in women who had preeclampsia and women who had not (controls). We found that preeclampsia was associated with a higher prevalence of diurnal and nocturnal ambulatory hypertension. Among women with preeclampsia, half of them were still hypertensive in the postpartum, with an increased prevalence of white coat and masked hypertension. They also had an abnormal circadian rhythm with a significant proportion of reversed rhythm. The index of salt-sensitivity risk, calculated from ambulatory blood pressure monitoring parameters, was significantly increased after preeclampsia. Individually, and in the general population, these hypertensive phenotypes are associated with a higher risk for cardiovascular disease later in life. Whether they are contributing factors or a consequence of preeclampsia is not known. Ambulatory blood pressure monitoring after preeclampsia is useful and helps to identify high-risk women. Early lifestyle modifications and regular medical follow-up should be offered to these women. The impact of these measures on future cardiovascular events remains of course to be determined in prospective trials.Myeloid-Derived Suppressor Cells, Cyclo sporine A, and Hypertension (p 199)Download figureDownload PowerPointCyclosporine A (CsA) is prescribed to reduce focal segmental glomerulosclerosis, membranous nephropathy, psoriasis, rheumatoid arthritis, and other autoimmune diseases despite the known prohypertensive side effect. Until new immunosuppressive drugs for these disorders are developed and used routinely in patients, strategies to blunt the negative cardiovascular and renal effects of CsA are needed. We demonstrate that augmenting a particular regulatory immune cell subset, myeloid-derived suppressor cells (MDSCs), is able to eradicate the hypertension, endothelial dysfunction, and vascular and glomerular injury caused by CsA in mice. The protective effects of increased MDSC levels caused by both interleukin-33 treatment and adoptive transfer of MDSCs demonstrate that CsA toxicity can be prevented and reversed. Beneficial effects of MDSCs have been reported in other forms of experimental hypertension and in various inflammatory and autoimmune diseases; therefore, autologous cell therapy with MDSCs may be feasible soon. Groups are generating MDSCs from various cells, including mouse embryonic stem cells and hematopoietic stem cells, as well as human peripheral blood mononuclear cells. Given the strong antihypertensive and organ-protective effects, MDSC therapy should be tested in patients being treated with CsA.Pregnancy History and Cerebrovascular Reactivity (p 110)Download figureDownload PowerPointHypertension during pregnancy is associated with an increased risk of developing cardiovascular or cerebrovascular disease later in life. Our group has shown that postmenopausal women who have experienced preeclampsia have lower brain volume and cognitive scores compared with women who had a normotensive pregnancy. The mechanisms underlying the interaction between pregnancy history and brain structure and function have not been elucidated. Because pregnancy-related changes in the circulation may contribute to pathological changes in the brain, we investigated cerebral blood flow reactivity and markers of vascular activation in women with a history of preeclampsia. In this study in Hypertension, women who either had a normotensive or preeclamptic pregnancy between 1976 and 1982 were recruited ≈35 years after the pregnancy. Women with a history of preeclampsia had lower cerebral blood flow velocity and reduced cerebrovascular reactivity, indicating cerebral microvascular dysfunction, compared with women with a history of normotensive pregnancy. Additionally, procoagulant circulating blood elements were associated with cerebral hemodynamic variables only in women with history of preeclampsia. Collectively, these results suggest that differences in circulating vasoactive factors in women with a history of preeclampsia might affect the reactivity of the cerebral circulation years beyond the preeclamptic pregnancy. These differences may contribute to brain atrophy and increased risk of cognitive decline in women with a history of preeclampsia. Previous Back to top Next FiguresReferencesRelatedDetails January 2018Vol 71, Issue 1 Advertisement Article InformationMetrics © 2017 American Heart Association, Inc.https://doi.org/10.1161/HYPERTENSIONAHA.117.10603 Originally publishedJanuary 1, 2018 PDF download Advertisement

Current and novel biomarkers in anti-neutrophil cytoplasm-associated vasculitis.

Anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) is characterized by a variable disease course, with up to 50% of patients having one relapse within 5 years and many progressing to end-stage organ damage despite modern treatment strategies. Moreover, complications arising from treatment dominate the causes of mortality and morbidity both early and late during disease, especially in the elderly and those with severe renal involvement, and there is additional uncertainty as to how long treatment should be continued. There is, therefore, an urgent clinical need to identify robust biomarkers to better predict treatment responses, risk of disease relapse and eventual complete clinical and immunological quiescence. To date, no such biomarkers exist, but better understanding of disease pathogenesis and the underlying immune dysfunction has provided some potential candidates linked to the discovery of new antibodies, different leukocyte activation states, the role of the alternative complement pathway and markers of vascular activation. With all promising new biomarkers, there is the need to rapidly replicate and validate early findings using large biobanks of samples that could be brought together by leaders in the field.

Epstein–Barr Virus Infection Induces Aberrant TLR Activation Pathway and Fibroblast–Myofibroblast Conversion in Scleroderma

Scleroderma (SSc) is a complex and heterogeneous connective tissue disease mainly characterized by autoimmunity, vascular damage, and fibrosis that mostly involve the skin and lungs. Epstein–Barr virus (EBV) is a lymphotropic γ-herpesvirus that has co-evolved with human species, infecting >95% of the adult population worldwide, and has been a leading candidate in triggering several autoimmune diseases. Here we show that EBV establishes infection in the majority of fibroblasts and endothelial cells in the skin of SSc patients, characterized by the expression of the EBV noncoding small RNAs (EBERs) and the increased expression of immediate-early lytic and latency mRNAs and proteins. We report that EBV is able to persistently infect human SSc fibroblasts in vitro, inducing an aberrant innate immune response in infected cells. EBV–Toll-like receptor (TLR) aberrant activation induces the expression of selected IFN-regulatory factors (IRFs), IFN-stimulated genes (ISGs), transforming growth factor-β1 (TGFβ1), and several markers of fibroblast activation, such as smooth muscle actin and Endothelin-1, and all of these genes play a key role in determining the profibrotic phenotype in SSc fibroblasts. These findings imply that EBV infection occurring in mesenchymal, endothelial, and immune cells of SSc patients may underlie the main pathological features of SSc including autoimmunity, vasculopathy, and fibrosis, and provide a unified disease mechanism represented by EBV reactivation.

Circulating microparticles and plasma levels of soluble E- and P-selectins in patients with systemic sclerosis

Objectives: Microparticles (MPs) may be involved in the pathogenesis of systemic sclerosis (SSc), which includes vasculopathy, endothelial cell activation, and coagulation activation. Circulating MPs from SSc patients were characterized and their relationship with soluble markers of vascular activation investigated.Method: This study included 121 SSc patients [79 with limited (lcSSc) and 42 with diffuse cutaneous SSc (dcSSc)] and 49 sex- and age-matched healthy controls (HCs). The MPs were characterized by flow cytometry for annexin V (AnxV)-binding capacity and their expression of surface markers of platelets (PMPs), leucocytes (LMPs), or endothelial cells (EMPs). Plasma levels of soluble (s) E- and P-selectins were determined by enzyme-linked immunosorbent assay (ELISA).Results: The total concentrations of MPs and of PMPs, LMPs, and EMPs were 22−42% lower in SSc patients than in HCs (p < 0.001). However, within the cell-derived MP pool, a 47% higher fraction of AnxV non-binding MPs (F-AnxV− MPs) was found in the SSc patients compared to the HCs (p < 0.05). The plasma levels of sE- and sP-selectins were increased by 47−64% in the SSc patients compared to HCs (p < 0.001). Multiple regression analysis showed that the raised plasma levels of sE- and sP-selectin were associated with F-AnxV– EMPs in dcSSc patients (p = 0.008 and p = 0.001, respectively) but not in lcSSc patients (p = 0.33 and p = 0.82, respectively).Conclusions: While the total number of MPs was decreased, the number of F-AnxV– MPs increased in SSc patients. The F-AnxV– EMPs were associated with plasma levels of markers of vascular activation in patients with dcSSc.

DsRNA activation of endothelin-1 and markers of vascular activation in endothelial cells and fibroblasts

BackgroundIn patients with systemic sclerosis (SSc), the relationship between innate immune activation, represented by increased expression of interferon (IFN)-regulated genes, and vascular injury/activation, manifest by increased endothelin-1 (ET-1), endothelin converting...

Vascular Effects of Ultrafine Particles in Persons with Type 2 Diabetes

BackgroundDiabetes confers an increased risk for cardiovascular effects of airborne particles.ObjectiveWe hypothesized that inhalation of elemental carbon ultrafine particles (UFP) would activate blood platelets and vascular endothelium in people with type 2 diabetes.MethodsIn a randomized, double-blind, crossover trial, 19 subjects with type 2 diabetes inhaled filtered air or 50 μg/m3 elemental carbon UFP (count median diameter, 32 nm) by mouthpiece for 2 hr at rest. We repeatedly measured markers of vascular activation, coagulation, and systemic inflammation before and after exposure.ResultsCompared with air, particle exposure increased platelet expression of CD40 ligand (CD40L) and the number of platelet-leukocyte conjugates 3.5 hr after exposure. Soluble CD40L decreased with UFP exposure. Plasma von Willebrand factor increased immediately after exposure. There were no effects of particles on plasma tissue factor, coagulation factors VII or IX, or D-dimer.ConclusionsInhalation of elemental carbon UFP for 2-hr transiently activated platelets, and possibly the vascular endothelium, in people with type 2 diabetes.

Lack of inhibitory effects of the anti-fibrotic drug imatinib on endothelial cell functions in vitro and in vivo.

Systemic sclerosis (SSc) is a systemic autoimmune disease that is characterized by microangiopathy with progressive loss of capillaries and tissue fibrosis. Imatinib exerts potent anti-fibrotic effects and is currently evaluated in clinical trials. The aim of the present study was to exclude that the anti-fibrotic effects of imatinib are complicated by inhibitory effects on endothelial cell functions, which might augment vascular disease in SSc. Endothelial cells and mice were treated with pharmacologically relevant concentrations of imatinib. The expression of markers of vascular activation was assessed with real-time PCR. Proliferation was analysed with the cell counting experiments and the MTT assay. Apoptosis was quantified with caspase 3 assays, annexin V in vitro and with TUNEL staining in vivo. Migration was studied with scratch and transwell assays. Tube forming was investigated with the matrigel assay. Imatinib did not alter the expression of markers of vascular activation. Imatinib did not increase the percentage of annexin V positive cells or the activity of caspase 3. No reduction in proliferation or metabolic activity of endothelial cells was observed. Imatinib did not affect migration of endothelial cells and did not reduce the formation of capillary tubes. Consistent with the in vitro data, no difference in the number of apoptotic endothelial cells was observed in vivo in mice treated with imatinib. Imatinib does not inhibit activation, viability, proliferation, migration or tube forming of endothelial cells in vitro and in vivo. Thus, treatment with imatinib might not augment further endothelial cell damage in SSc.

Antiretroviral therapy reduces markers of endothelial and coagulation activation in patients infected with human immunodeficiency virus type 1.

We investigated the effect of antiretroviral therapy on vascular activation in 41 human immunodeficiency (HIV)--infected patients receiving a regimen that included either at least 1 protease inhibitor (PI; n = 21) or a nonnucleoside reverse-transcriptase inhibitor (NNRTI; n = 20). A control group of 21 healthy subjects was included for comparison. Levels of endothelial markers (soluble vascular cell adhesion molecule [sVCAM]--1, soluble intercellular adhesion molecule--1, and von Willebrand factor) were higher in HIV-infected persons before treatment than in control subjects and decreased significantly after 5--13 months of treatment. Levels of sVCAM-1 and von Willebrand factor correlated significantly with initial virus load. d-dimer concentrations also decreased significantly after initiation of treatment. PI- and NNRTI-containing regimens had similar effects. Therapy did not reduce levels of the soluble platelet (sP) activation markers sP-selectin and CD40 ligand. The inhibition of markers of vascular activation may counterbalance sequelae of therapy-induced dyslipidemia and potentially prevent development of atherosclerosis in HIV-infected patients.