Vascular pentraxin 3 controls arterial thrombosis by targeting collagen and fibrinogen induced platelets aggregation.

AIM: The long pentraxin PTX3 plays a non-redundant role during acute myocardial infarction, atherosclerosis and in the orchestration of tissue repair and remodeling during vascular injury, clotting and fibrin deposition. The aim of this work is to investigate the molecular mechanisms underlying the protective role of PTX3 during arterial thrombosis. METHODS AND RESULTS: PTX3 KO mice transplanted with bone marrow from WT or PTX3 KO mice presented a significant reduction in carotid artery blood flow following FeCl3 induced arterial thrombosis (-80.36±11.5% and -95.53±4.46%), while in WT mice transplanted with bone marrow from either WT or PTX3 KO mice, the reduction was less dramatic (-45.55±1.37% and -53.39±9.8%), thus pointing to a protective effect independent of a hematopoietic cell's derived PTX3. By using P-selectin/PTX3 double KO mice, we further excluded a role for P-selectin, a target of PTX3 released by neutrophils, in vascular protection played by PTX3. In agreement with a minor role for hematopoietic cell-derived PTX3, platelet activation (assessed by flow cytometric expression of markers of platelet activation) was similar in PTX3 KO and WT mice as were haemostatic properties. Histological analysis indicated that PTX3 localizes within the thrombus and the vessel wall, and specific experiments with the N-terminal and the C-terminal PTX3 domain showed the ability of PTX3 to selectively dampen either fibrinogen or collagen induced platelet adhesion and aggregation. CONCLUSION: PTX3 interacts with fibrinogen and collagen and, by dampening their pro-thrombotic effects, plays a protective role during arterial thrombosis.

Evaluation of oil-palm fungal disease infestation with canopy hyperspectral reflectance data.

Fungal disease detection in perennial crops is a major issue in estate management and production. However, nowadays such diagnostics are long and difficult when only made from visual symptom observation, and very expensive and damaging when based on root or stem tissue chemical analysis. As an alternative, we propose in this study to evaluate the potential of hyperspectral reflectance data to help detecting the disease efficiently without destruction of tissues. This study focuses on the calibration of a statistical model of discrimination between several stages of Ganoderma attack on oil palm trees, based on field hyperspectral measurements at tree scale. Field protocol and measurements are first described. Then, combinations of pre-processing, partial least square regression and linear discriminant analysis are tested on about hundred samples to prove the efficiency of canopy reflectance in providing information about the plant sanitary status. A robust algorithm is thus derived, allowing classifying oil-palm in a 4-level typology, based on disease severity from healthy to critically sick stages, with a global performance close to 94%. Moreover, this model discriminates sick from healthy trees with a confidence level of almost 98%. Applications and further improvements of this experiment are finally discussed.

Endogenous PTX3 translocates at the membrane of late apoptotic human neutrophils and is involved in their engulfment by macrophages.

Neutrophils are short-lived innate immune cells that rapidly die by apoptosis. A rapid and efficient clearance of apoptotic cells is crucial to avoid autoimmunity. This process involves cell alterations, endocytic receptors expressed by phagocytic cells and soluble bridging molecules (opsonins) that facilitate internalization of apoptotic cells by phagocytes. Neutrophils constitutively express the prototypic long pentraxin PTX3 that binds to apoptotic cells and modulates their clearance. We thus evaluated whether endogenous PTX3 may interfere with the capture of apoptotic neutrophils. We observed that PTX3 accumulates in blebs at the surface of late apoptotic neutrophils, resulting from its active translocation from granules to the membrane. A neutralizing anti-PTX3 monoclonal Ab (mAb) inhibits the capture of late apoptotic neutrophils by macrophages. This study shows that intracellular PTX3 translocates at the surface of late apoptotic neutrophils and acts as an 'eat-me' molecule for their recognition and capture by macrophages.

Expression of long pentraxin PTX3 in human adipose tissue and its relation with cardiovascular risk factors.

UNLABELLED: Pentraxin 3 (PTX3) is an acute phase protein strongly expressed by advanced atherosclerotic lesions. We investigated (a) PTX3 expression and secretion in subcutaneous adipose tissue (SAT) and omental visceral adipose tissue (VAT) obtained from 21 obese (37.4+/-8.15 yr) and 10 normal weight subjects (43.7+/-11.07 yr) and (b) the relationships of adipose PTX3 with tumour necrosis factor alpha (TNFalpha) and adiponectin expression and with cardiometabolic risk factors. Real-time PCR was used to quantify specific mRNA for PTX3, CD68 (macrophage marker), TNFalpha and adiponectin. Fresh adipose tissue was cultured and PTX3 measured in the medium. Serum insulin, glucose, HDL and LDL cholesterol, triglycerides, C-reactive protein (CRP), fibrinogen, adiponectin, TNFalpha and PTX3 were measured. PTX3 expression was similar in the two fat compartments and tended to be higher in obese than in normal weight subjects in VAT only (p=0.05). CD68 and PTX3 expressions were correlated with each other in SAT but not in VAT. After adjustment for age and sex, VAT-PTX3 expression and release were correlated with VAT-TNFalpha expression (p<0.01 for both) and with LDL/HDL ratio (p<0.01 and p<0.001). VAT-PTX3 expression was also correlated with BMI, triglycerides, CRP, fibrinogen and adiponectin (p<0.05 for all). In the multivariate analysis with VAT-PTX3 RNA levels as dependent variable, LDL/HDL ratio and fibrinogen remained independently associated with VAT-PTX3 expression (p<0.01 for both). These associations were not seen within SAT. CONCLUSIONS: Human adipose tissue expresses and releases PTX3 likely under TNFalpha control. VAT production of PTX3 seems to contribute to the mechanisms underlying the development of atherosclerosis.

[Role of inflammation mediators in the pathogenesis of heart failure]. / Ruolo dei mediatori dell'infiammazione nella patogenesi dello scompenso cardiaco.

A number of factors are involved in congestive heart failure pathogenesis. Among these, inflammatory mediators could have a crucial role. Patients with congestive heart failure show increased plasma levels of "proinflammatory cytokines", in particular tumor necrosis factor-alpha and interleukin-6. Clinical and experimental models have demonstrated that these cytokines induce left ventricular dysfunction, pulmonary edema, ventricular remodeling, skeletal muscle abnormalities, myocyte apoptosis and endothelial dysfunction, suggesting the possibility that increased plasma concentration of cytokines could not be just an epiphenomenon, but an effective pathogenetic mechanism of disease progression. Additional inflammatory proteins involved in the acute phase response could play a part in the pathogenesis of heart failure. Pentraxin 3 is a prototypical long pentraxin, structurally related, although with different functions, to C-reactive protein, is produced by immune system cells, fibroblasts and particularly by cardiac endothelial cells and myocytes, as demonstrated in murine and human models. Its synthesis is rapidly induced after exposition to bacterial lipopolysaccharide and proinflammatory cytokines, as interleukin-1beta and tumor necrosis factor-alpha. In heart diseases, pentraxin 3 could be involved in the acute local inflammatory response to myocardial injury (e.g. necrosis) and in heart failure pathogenetic mechanisms, but its exact role is not yet settled. Defining the specific part played by these molecules in the pathogenesis of heart failure could lead to new therapeutic approaches in the treatment of cardiac insufficiency.

Circulating levels of the long pentraxin PTX3 correlate with severity of infection in critically ill patients.

OBJECTIVE: To evaluate the recently discovered long pentraxin PTX3 in plasma of critically ill patients and to compare it with the classic short pentraxin C-reactive protein and with other indicators of inflammation. DESIGN: A cohort study on plasma samples. SETTING: Medical intensive care unit (ICU) of the University Hospital of Basel. PATIENTS: A total of 101 consecutive critically ill patients admitted to the medical ICU. INTERVENTIONS: Venous blood samples were routinely obtained at entry, on day 2, and at discharge or before death. MEASUREMENTS AND MAIN RESULTS: Plasma samples were obtained from 101 consecutive critically ill patients admitted to the ICU with systemic inflammatory response syndrome, sepsis, or septic shock. PTX3 plasma levels were measured by enzyme-linked immunosorbent assay. PTX3 was elevated in critically ill patients, with a gradient from systemic inflammatory response syndrome to septic shock. PTX3 levels correlated with clinical scores reflecting severity of disease (e.g., Acute Physiology and Chronic Health Evaluation II: p =.00097). In addition, high levels of PTX3 were associated with unfavorable outcome. CONCLUSIONS: The long pentraxin PTX3 is elevated in critically ill patients and correlates with severity of disease and infection. Compared with the short pentraxin C-reactive protein, PTX3 may be a more direct indicator of tissue involvement by inflammatory and infectious processes.

PTX3 in small-vessel vasculitides: an independent indicator of disease activity produced at sites of inflammation.

OBJECTIVE: To verify whether the prototypical long pentraxin PTX3 represents an indicator of the activity of small-vessel vasculitis. METHODS: Concentrations of PTX3, a pentraxin induced in endothelium by cytokines, were measured by enzyme-linked immunosorbent assay in the sera of 43 patients with Churg-Strauss syndrome, Wegener's granulomatosis, and microscopic polyangiitis. PTX3 was also measured in the sera of 28 patients with systemic lupus erythematosus (SLE), 22 with rheumatoid arthritis, and 16 with CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias). Serum concentrations of C-reactive protein (CRP) were measured by immunoturbidimetry. The cells involved in PTX3 production in vivo were identified in skin biopsy samples. RESULTS: Patients with active vasculitis had significantly higher concentrations of PTX3 than did those with quiescent disease (P < 0.001). PTX3 levels in the latter group were similar to those in healthy controls. PTX3 levels were higher in patients with untreated vasculitis and lower in patients who underwent immunosuppressive treatments (P < 0.005). In contrast, patients with active SLE had negligible levels of the pentraxin. PTX3 levels did not correlate with CRP levels in vasculitis patients. Endothelial cells produced PTX3 in active skin lesions. CONCLUSION: PTX3 represents a novel acute-phase reactant produced at sites of active vasculitis.

The long pentraxin PTX3 binds to apoptotic cells and regulates their clearance by antigen-presenting dendritic cells.

Pentraxins are acute-phase proteins produced in vivo during inflammatory reactions. Classical short pentraxins, C-reactive protein, and serum amyloid P component are generated in the liver in response to interleukin (IL)-6. The long pentraxin PTX3 is produced in tissues under the control of primary proinflammatory signals, such as lipopolysaccharide, IL-1 beta, and tumor necrosis factor-alpha, which also promote maturation of dendritic cells (DCs). Cell death commonly occurs during inflammatory reactions. In this study, it is shown that PTX3 specifically binds to dying cells. The binding was dose dependent and saturable. Recognition was restricted to extranuclear membrane domains and to a chronological window after UV irradiation or after CD95 cross-linking-induced or spontaneous cell death in vitro. PTX3 bound to necrotic cells to a lesser extent. Human DCs failed to internalize dying cells in the presence of PTX3, while they took up normally soluble or inert particulate substrates. These results suggest that PTX3 sequesters cell remnants from antigen-presenting cells, possibly contributing to preventing the onset of autoimmune reactions in inflamed tissues. (Blood. 2000;96:4300-4306)

Expression and production of the long pentraxin PTX3 in rheumatoid arthritis (RA).

PTX3 is a secreted molecule which consists of a C-terminal domain similar to classical pentraxins (e.g. C-reactive protein (CRP)) and of an unrelated N-terminal domain. Unlike the classical pentraxins, the long pentraxin PTX3 is expressed in response to IL-1beta and tumour necrosis factor-alpha (TNF-alpha), but not to IL-6, in various cell types. The present study was designed to investigate the expression of PTX3 in RA. Dissociated RA and osteoarthritis (OA) type B synoviocytes were cultured in the presence and in the absence of inflammatory cytokines. PTX3 mRNA expression in synoviocytes was evaluated by Northern analysis. PTX3 protein levels in synovial cell cultures and synovial fluid were estimated by ELISA, and PTX3 distribution in synovial tissues by immunohistochemical techniques. OA synoviocytes were induced to express high levels of PTX3 mRNA by TNF-alpha, but not by other cytokines including IL-1beta and IL-6. RA synoviocytes, unlike OA synoviocytes, constitutively expressed high levels of PTX3 in the absence of deliberate stimulation. The constitutive expression of PTX3 in RA synoviocytes was not modified by anti-TNF-alpha antibodies, IL-1 receptor antagonist or a combination of the two agents. In contrast, interferon-gamma and transforming growth factor-beta inhibited PTX3 constitutive expression in RA synoviocytes. The joint fluid from RA patients contained higher levels of immunoreactive PTX3 than controls and the synovial tissue contained endothelial cells and synoviocytes positive for PTX3 by immunohistochemistry. In conclusion, PTX3 may play a role in inflammatory circuits of RA, and its relevance as a marker of disease activity deserves further study.

Uncoupling of inflammatory chemokine receptors by IL-10: generation of functional decoys.

As originally demonstrated for the interleukin 1 (IL-1) type II receptor, some primary proinflammatory cytokines from the IL-1 and tumor necrosis factor families are regulated by decoy receptors that are structurally incapable of signaling. Here we report that concomitant exposure to proinflammatory signals and IL-10 generates functional decoy receptors in the chemokine system. Inflammatory signals, which cause dendritic cell (DC) maturation and migration to lymphoid organs, induce a chemokine receptor switch, with down-regulation of inflammatory receptors (such as CCR1, CCR2, CCR5) and induction of CCR7. Concomitant exposure to lipopolysaccharide (LPS) and IL-10 blocks the chemokine receptor switch associated with DC maturation. LPS + IL-10-treated DCs showed low expression of CCR7 and high expression of CCR1, CCR2 and CCR5. These receptors were unable to elicit migration. We provide evidence that uncoupled receptors, expressed on LPS + IL-10-treated cells, sequester and scavenge inflammatory chemokines. Similar results were obtained for monocytes exposed to activating signals and IL-10. Thus, in an inflammatory environment, IL-10 generates functional decoy receptors on DC and monocytes, which act as molecular sinks and scavengers for inflammatory chemokines.

Chemokines, sTNF-Rs and sCD30 serum levels in healthy aged people and centenarians.

Several lines of evidence point to a profound remodelling of the cytokine network in healthy elderly subjects, with decreased type-1 cytokine production (IL 2) and a shift to type 0 and 2. We have also observed an increase of proinflammatory cytokines (IL-1, IL-6, TNF-alpha) in vitro, and an increase of circulating stem cell factor in vivo. In this setting, we studied changes of chemokines (MCP-1 and RANTES) with aging, as well as other molecules, namely, sTNF-RI and sTNF-RII, and the soluble form of the CD30 molecule (sCD30), involved in the pro- and antiinflammatory cytokine balance. The subjects enrolled in the study belonged to three different selected healthy groups of young, aged and centenarians. The presence of rheumatoid factor (RF) and antinuclear antibodies (ANA) was simultaneously assessed. The results show that MCP-1 serum levels were higher in the healthy aged and lowest in the young, while RANTES increased exclusively in centenarians. Only centenarians had autoantibodies (ANA and RF). sTNF-RI and sTNF-RII were significantly elevated in healthy old subjects compared to the young, and even higher in selected centenarians compared to the other age groups. sCD30 serum levels were significantly raised in centenarians compared to the young, despite absence of circulating CD30+ cells in the peripheral blood of the whole study population. No relationship among serum values of these different members of the TNF-R family was found, despite a strong correlation for sTNF-RI and sTNF-RII in all groups. We hypothesize that the increased chemokine levels in aged people, and raised sCD30 levels in centenarians, may reflect a general shift towards type 0/2 cytokines in normal aging, which may be responsible, at least in part, for the appearance of circulating autoantibodies without definite clinical consequences at advanced age.

Plasma concentration of C-reactive protein is increased in type I diabetic patients without clinical macroangiopathy and correlates with markers of endothelial dysfunction: evidence for chronic inflammation.

Moderately increased plasma concentrations of C-reactive protein are associated with an increased risk of cardiovascular disease. C-reactive protein, its relation to a low degree of inflammatory activation and its association with activation of the endothelium have not been systematically investigated in Type I (insulin-dependent) diabetes mellitus. C-reactive protein concentrations were measured in 40 non-smoking patients with Type I diabetes without symptoms of macrovascular disease and in healthy control subjects, and in a second group of Type I diabetic patients (n = 60) with normo- (n = 20), micro- (n = 20) or macroalbuminuria (n = 20). Differences in glycosylation of alpha1-acid glycoprotein were assayed by crossed affinity immunoelectrophoresis. Activation of the endothelium was measured with plasma concentrations of endothelial cell markers. The median plasma concentration of C-reactive protein was higher in Type I diabetic patients compared with healthy control subjects [1.20 (0.06-21.64) vs. 0.51 (0.04-9.44) mg/l; p<0.02]. The Type I diabetic subjects had a significantly increased relative amount of fucosylated alpha1-acid glycoprotein (79+/-12% vs. 69+/-14% in the healthy control subjects; p<0.005), indicating a chronic hepatic inflammatory response. In the Type I diabetic group, log(C-reactive protein) correlated significantly with von Willebrand factor (r = 0.439, p<0.005) and vascular cell adhesion molecule-1 (r = 0.384, p<0.02), but not with sE-selectin (r = 0.008, p = 0.96). In the second group of Type I diabetic patients, increased urinary albumin excretion was associated with a significant increase of von Willebrand factor (p<0.0005) and C-reactive protein (p = 0.003), which were strongly correlated (r = 0.53, p<0.0005). Plasma concentrations of C-reactive protein were higher in Type I diabetic patients without (clinical) macroangiopathy than in control subjects, probably due to a chronic hepatic inflammatory response. The correlation of C-reactive protein with markers of endothelial dysfunction suggests a relation between activation of the endothelium and chronic inflammation.

Characterization of type II intracellular IL-1 receptor antagonist (IL-1ra3): a depot IL-1ra.

Three molecular forms of the IL-1 receptor antagonist (IL-1ra) have been identified and cloned. Secreted IL-1ra (sIL-1ra or IL-1ra1) contains a classical leader peptide giving a released mature protein. Two intracellular isoforms, icIL-1ra type I (IL-1ra2) and icIL-1ra type II (IL-1ra3), have no leader sequence, thus predicting that these proteins remain intracellular. In an effort to define its biological role, we structurally and functionally characterized IL-1ra3. Endogenous immunoreactive IL-1ra3 was detected in a variety of inflammatory cells and tissues. We used a gene transfer strategy to explore the possible intracellular functions of IL-1ra3 (and IL-1ra2) and the cell-associated agonist IL-1alpha. The intracellular IL-1ra3 isoform, as well as IL-1ra2, does not block the action of exogenous and endogenous IL-1 under these conditions. Intact IL-1ra3 was released from the cells killed by NK effectors. The intracellular isoforms may represent a reservoir of IL-1ra, released upon cell death, whose function is to limit the pro-inflammatory action of cell debris.

Suppression of juvenile chronic myelogenous leukemia colony growth by interleukin-1 receptor antagonist.

Bone marrow (BM) and peripheral blood (PB) cells from patients with juvenile chronic myelogenous leukemia (JCML) exhibit spontaneous in vitro proliferation. Several cytokines including granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 beta (IL-1 beta), and tumor necrosis factor alpha (TNF alpha) have been implicated in supporting the growth of leukemic monocyte-macrophage colonies either by autocrine or paracrine pathways. In seven untreated JCML patients, we investigated the role of IL-1 in the spontaneous growth of these cells by specifically blocking IL-1 receptors. The IL-1 receptor antagonist (IL-1 Ra) was added to the clonogenic assays, and in each case significant (mean = 63%, range = 35% to 82%) inhibition of spontaneous proliferation was observed. Uncultured circulating cells from PB or BM of four out of five patients expressed IL-1 beta-specific mRNA and secreted the protein into the culture supernatants. Moreover, by means of reverse transcriptase-polymerase chain reaction (RT-PCR), we demonstrated that most of the spontaneously growing leukemic colony-forming unit cells (CFU-C) obtained from BM cells of two patients were positive for the presence of the IL-1 beta-specific mRNA. Despite the presence of a measurable amount of GM-CSF in JCML cell culture supernatants, GM-CSF-specific mRNA in CFU-C cells of four cases was not detected by RT-PCR. These data further support a central role for IL-1 beta in the pathogenesis of JCML and suggest that the use of IL-1 Ra could represent a novel therapeutic strategy against this disorder.

[Defibrotide versus heparin in antithrombotic prophylaxis in gynecological surgery]. / Defibrotide versus eparina nella profilassi antitrombotica in chirurgia ginecologica.

Deep venous thrombosis (DVT) can be a significant complication of the postoperative course in gynaecological surgery, because of traumatism and compression to which the vascular pelvic structures are subjected. A protocol was therefore designed to evaluate the effectiveness and tolerability of defibrotide, a new antithrombotic and profibrinolytic drug, compared with low-dose heparin. The study was conducted on 102 women, undergoing major gynaecological surgery for benign and malignant affections, randomly assigned to the following two treatment groups. A) defibrotide (400 mg i.v./i.m. b.i.d., starting the day before the surgery for 8 days); B) calcium heparin (5000 IU s.c. b.i.d., starting on the day of surgery, for/days). Clinical, haematological and instrumental (Doppler ultrasound) parameters were assessed and no major events were noted in either of the two treatment groups though in the calcium heparin group, 2 patients showed clinical signs of DVT (not confirmed by Doppler ultrasound) and no side effects were noticed, except for a cutaneous rash in one defibrotide patient and an episode of bleeding on the third postoperative day in a patient treated with calcium heparin. Defibrotide proved as effective as calcium heparin in the prevention of DVT in gynaecological surgery.

[Pharmacologic prevention of deep postoperative venous thrombosis in general surgery]. / Profilassi farmacologica della trombosi venosa profonda post-operatoria in chirurgia generale.

The most commonly used pharmacological aids employed in the prevention of peroperative deep venous thrombosis in general surgery are reviewed in brief. The probable action mechanisms, recommended doses, laboratory parameters to be monitored, side-effects, contraindications and effectiveness shown in the main clinical trials carried out are illustrated.

Hemostatic Balance Index in TIA patients: sex-related changes.

In order to evaluate the occurrence of hemostatic disorders, 37 patients with transient ischemic attacks (TIAs) and 50 control subjects were studied by means of the Hemostatic Balance Index (H.B.I.) derived from Raby's Thrombodynamic Potential Index (T.P.I.) and Fearnley's Whole Blood Diluted Lysis Time (W.B.D.L.T.). Results showed a significant increase in T.P.I. and a tendency to a decrease in fibrinolytic activity in the TIA group: H.B.I. was shown to be significantly increased, thus indicating a pro-thrombotic imbalance in these patients. The occurrence of similar changes in TIA females when compared to male patients marks the importance of plasmatic factors in the mechanism of thrombotic disorders in females with cerebrovascular disease.

Hemostatic disorders in 25 patients with limited and uncomplicated thyroid and breast cancer: prophylactic and therapeutic considerations.

In order to evaluate the efficacy of an anticoagulant treatment in neoplasia, we have looked for the existence and the possible role of hemostatic unbalance in patients affected by limited and uncomplicated thyroid and breast cancer by examining hemostasis in 25 patients. Our data allowed us to evidentiate an accelerated and increased fibrinoformation associated with the presence of plasminogen's activation inhibitor which overlaps the increased plasminogen's activators. We evidentiated also an increase of platelet functions in vitro and of their activation in vivo. These findings support the hypothesis of a possible role played by hemostasis alterations in the pathogenesis of thromboembolic complications, cancer growth and/or metastatization, and justify prophylactic and therapeutic anticoagulation.

[Methodological specifications on the Todd method and preliminary results]. / Precisazioni metodologiche sul metodo di todd e risultati preliminari.

In order to measure the potentiality and kinetics tissue fibrinolysis we have modified Todd's histochemical method preparing at least six sections taken from same sample tissue, by infraoperatory biopsy, esponing them to a fibrin film at a constant concentration; we have also chosen to incubate the section at 10, 20, 30, 45, 60 min. The measurement of the areas of fibrin, of tissue and fibrinolysis, at the above mentioned times, has been effected at standard magnification (15 X) by an image analyser (Videoplan) scale 1:8. For each sample we suggest to elaborate an Index of the Potentiality of Fibrinolysis (formula; see text) and an Index of the Kinetics of the Fibrinolysis (formula; see text). Applying this method to two different groups of thyroid disease (struma and adenoma) we have not pointed out any statistically significant difference.