Anti Transglutaminase Antibodies Cause Ataxia in Mice

Background

Celiac disease (CD) is an autoimmune gastrointestinal disorder characterized by the presence of anti-transglutaminase 2 (TG2) and anti-gliadin antibodies. Amongst the neurological dysfunctions associated with CD, ataxia represents the most common one.

Methods

We analyzed by immunohistochemistry, the anti-neural reactivity of the serum from 20 CD patients. To determine the role of anti-TG2 antibodies in ataxia, two anti-TG2 single chain variable fragments (scFv), isolated from a phage-display IgA antibody library, were characterized by immunohistochemistry and ELISA, and injected in mice to study their effects on motor coordination. We found that 75% of the CD patient population without evidence of neurological involvement, has circulating anti-neural IgA and/or IgG antibodies. Two anti-TG2 scFvs, cloned from one CD patient, stained blood vessels but only one reacted with neurons. This anti-TG2 antibody showed cross reactivity with the transglutaminase isozymes TG3 and TG6. Intraventricular injection of the anti-TG2 or the anti-TG2/3/6 cross-reactive scFv provoked transient, equally intensive ataxia in mice.

Conclusion

The serum from CD patients contains anti-TG2, TG3 and TG6 antibodies that may potentially cause ataxia.     

Transglutaminase 2 cross-linking activity is linked to invadopodia formation and cartilage breakdown in arthritis

Introduction

The microenvironment surrounding inflamed synovium leads to the activation of fibroblast-like synoviocytes (FLSs), which are important contributors to cartilage destruction in rheumatoid arthritic (RA) joints. Transglutaminase 2 (TG2), an enzyme involved in extracellular matrix (ECM) cross-linking and remodeling, is activated by inflammatory signals. This study was undertaken to assess the potential contribution of TG2 to FLS-induced cartilage degradation.

Methods

Transglutaminase (TGase) activity and collagen degradation were assessed with the immunohistochemistry of control, collagen-induced arthritic (CIA) or TG2 knockdown (shRNA)-treated joint tissues. TGase activity in control (C-FLS) and arthritic (A-FLS) rat FLSs was measured by in situ 5-(biotinamido)-pentylamine incorporation. Invadopodia formation and functions were measured in rat FLSs and cells from normal (control; C-FLS) and RA patients (RA-FLS) by in situ ECM degradation. Immunoblotting, enzyme-linked immunosorbent assay (ELISA), and p3TP-Lux reporter assays were used to assess transforming growth factor-β (TGF-β) production and activation.

Results

TG2 and TGase activity were associated with cartilage degradation in CIA joints. In contrast, TGase activity and cartilage degradation were reduced in joints by TG2 knockdown. A-FLSs displayed higher TGase activity and TG2 expression in ECM than did C-FLSs. TG2 knockdown or TGase inhibition resulted in reduced invadopodia formation in rat and human arthritic FLSs. In contrast, increased invadopodia formation was noted in response to TGase activity induced by TGF-β, dithiothreitol (DTT), or TG2 overexpression. TG2-induced increases in invadopodia formation were blocked by TGF-β neutralization or inhibition of TGF-βR1.

Conclusions

TG2, through its TGase activity, is required for ECM degradation in arthritic FLS and CIA joints. Our findings provide a potential target to prevent cartilage degradation in RA.     

Dynamics of Immune Reconstitution and Activation Markers in HIV+ Treatment-Na?ve Patients Treated with Raltegravir,Tenofovir Disoproxil Fumarate and Emtricitabine

Background

The dynamics of CD4+ T cell reconstitution and changes in immune activation and inflammation in HIV-1 disease following initiation of antiretroviral therapy (ART) are incompletely defined and their underlying mechanisms poorly understood.

Methods

Thirty-nine treatment-naïve patients were treated with raltegravir, tenofovir DF and emtricitabine. Immunologic and inflammatory indices were examined in persons with sustained virologic control during 48 weeks of therapy.

Results

Initiation of ART increased CD4+ T cell numbers and decreased activation and cell cycle entry among CD4+ and CD8+ T cell subsets, and attenuated markers of coagulation (D-dimer levels) and inflammation (IL-6 and TNFr1). These indices decayed at different rates and almost all remained elevated above levels measured in HIV-seronegatives through 48 weeks of viral control. Greater first and second phase CD4+ T cell restoration was related to lower T cell activation and cell cycling at baseline, to their decay with treatment, and to baseline levels of selected inflammatory indices, but less so to their changes on therapy.

Conclusions

ART initiation results in dynamic changes in viral replication, T cell restoration, and indices of immune activation, inflammation, and coagulation. These findings suggest that determinants of T cell activation/cycling and inflammation/coagulation may have distinguishable impact on immune homeostasis.

Trial Registration

Clinicaltrials.gov NCT00660972     

Preserved Antigen-Specific Immune Response in Patients with Multiple Sclerosis Responding to IFNβ-Therapy

Background

Interferon-beta (IFNβ) regulates the expression of a complex set of pro- as well as anti-inflammatory genes. In cohorts of MS patients unstratified for therapeutic response to IFNβ, normal vaccine-specific immune responses have been observed. Data capturing antigen-specific immune responses in cohorts of subjects defined by response to IFNβ-therapy are not available.

Objective

To assess antigen-specific immune responses in a cohort of MS patients responding clinically and radiologically to IFNβ.

Methods

In 26 MS patients, clinical and MRI disease activity were assessed before and under treatment with IFNβ. Humoral and cellular immune response to influenza vaccine was prospectively characterized in these individuals, and 33 healthy controls by influenza-specific Enzyme-Linked Immunosorbent Assay (ELISA) and Enzyme Linked Immuno Spot Technique (ELISPOT).

Results

Related to pre-treatment disease activity, IFNβ reduced clinical and radiological MS disease-activity. Following influenza vaccination, frequencies of influenza-specific T cells and concentrations of anti-influenza A and B IgM and IgG increased comparably in MS-patients and in healthy controls.

Conclusions

By showing in a cohort of MS-patients responding to IFNβ vaccine-specific immune responses comparable to controls, this study indicates that antigen-specific immune responses can be preserved under successful IFNβ-therapy.     

Co-Culture of Human Bronchial Fibroblasts and CD4+ T Cells Increases Th17 Cytokine Signature

Background

Airway inflammation is an important characteristic of asthma and has been associated with airway remodelling and bronchial hyperreactivity. The mucosal microenvironment composed of structural cells and highly specialised extracellular matrix is able to amplify and promote inflammation. This microenvironment leads to the development and maintenance of a specific adaptive response characterized by Th2 and Th17. Bronchial fibroblasts produce multiple mediators that may play a role in maintaining and amplifying this response in asthma.

Objective

To investigate the role of bronchial fibroblasts obtained from asthmatic subjects and healthy controls in regulating Th17 response by creating a local micro-environment that promotes this response in the airways.

Methods

Human bronchial fibroblasts and CD4⁺T cells were isolated from atopic asthmatics and non-atopic healthy controls. CD4⁺T were co-cultured with bronchial fibroblasts of asthmatic subjects and healthy controls. RORc gene expression was detected by qPCR. Phosphorylated STAT-3 and RORγt were evaluated by western blots. Th17 phenotype was measured by flow cytometry. IL-22, IL17, IL-6 TGF-β and IL1-β were assessed by qPCR and ELISA.

Results

Co-culture of CD4⁺T cells with bronchial fibroblasts significantly stimulated RORc expression and induced a significant increase in Th17 cells as characterized by the percentage of IL-17⁺/CCR6⁺ staining in asthmatic conditions. IL-17 and IL-22 were increased in both normal and asthmatic conditions with a significantly higher amount in asthmatics compared to controls. IL-6, IL-1β, TGF-β and IL-23 were significantly elevated in fibroblasts from asthmatic subjects upon co-culture with CD4⁺T cells. IL-23 stimulates IL-6 and IL-1β expression by bronchial fibroblasts.

Conclusion

Interaction between bronchial fibroblasts and T cells seems to promote specifically Th17 cells profile in asthma. These results suggest that cellular interaction particularly between T cells and fibroblasts may play a pivotal role in the regulation of the inflammatory response in asthma.     

Roscovitine Suppresses CD4+ T Cells and T Cell-Mediated Experimental Uveitis

Background

T cells are essential for the development of uveitis and other autoimmune diseases. After initial activation, CD4+ lymphocytes express the co-stimulatory molecule OX40 that plays an important role in T cell proliferation. Cyclin dependent kinase 2 (CdK2) plays a pivotal role in the cell cycle transition from G1 to S phase. In addition, recent research has implicated CdK2 in T cell activation. Thus, we sought to test the immunosuppressive effect of roscovitine, a potent CdK2 inhibitor, on CD4+ T cell activation, proliferation, and function.

Design and Methods

Mouse CD4+ T cells were activated by anti-CD3 and anti-CD28 antibodies. The expression of OX40, CD44, and CdK2 were analyzed by flow cytometry. In addition, cell cycle progression and apoptosis of control and roscovitine-treated T lymphocytes were measured by BrdU incorporation and annexin V assay, respectively. Furthermore, the immunoregulatory effect of roscovitine was evaluated in both ovalbumin-induced uveitis and experimental autoimmune uveitis (EAU) models.

Results

In this study, we found that T cell activation induced OX40 expression. Cell cycle analysis showed that more CD4+OX40+ cells entered S phase than OX40- T cells. Concurrently, CD4+OX40+ cells had a higher level of CdK2 expression. Roscovitine treatment blocked activated CD4+ cells from entering S phase. In addition, roscovitine not only reduced the viability of CD4+ lymphocytes but also suppressed T cell activation and cytokine production. Finally, roscovitine significantly attenuated the severity of T cell-dependent, OX40-enhanced uveitis.

Conclusion

These results implicate CdK2 in OX40-augmented T cell response and expansion. Furthermore, this study suggests that roscovitine is a novel, promising, therapeutic agent for treating T cell-mediated diseases such as uveitis.     

Curcumin Suppresses Gelatinase B Mediated Norepinephrine Induced Stress in H9c2 Cardiomyocytes

Background

Extracellular matrix (ECM) remodeling facilitates biomechanical signals in response to abnormal physiological conditions. This process is witnessed as one of the major effects of the stress imposed by catecholamines, such as epinephrine and norepinephrine (NE), on cardiac muscle cells. Matrix metalloproteinases (MMPs) are the key proteases involved in degradation of the ECM in heart.

Objectives

The present study focuses on studying the effect of curcumin on Gelatinase B (MMP-9), an ECM remodeling regulatory enzyme, in NE-induced cardiac stress. Curcumin, a bioactive polyphenol found in the spice turmeric, has been studied for its multi-fold beneficial properties. This study focuses on investigating the role of curcumin as a cardio-protectant.

Methods

H9c2 cardiomyocytes were subjected to NE and curcumin treatments to study the response in stress conditions. Effect on total collagen content was studied using Picrosirus red staining. Gelatinase B activity was assessed through Gel-Diffusion Assay and Zymographic techniques. RT-PCR, Western Blotting and Immunocytochemistry were performed to study effect on expression of gelatinase B. Further, the effect of curcumin on the localization of NF-κB, known to regulate gelatinase B, was also examined.

Results

Curcumin suppressed the increase in the total collagen content under hypertrophic stress and was found to inhibit the in-gel and in-situ gelatinolytic activity of gelatinase B. Moreover, it was found to suppress the mRNA and protein expression of gelatinase B.

Conclusions

The study provides an evidence for an overall inhibitory effect of curcumin on Gelatinase B in NE-induced hypertrophic stress in H9c2 cardiomyocytes which may contribute in the prevention of ECM remodeling.     

Angiopoietin-Like 7 Is an Anti-Angiogenic Protein Required to Prevent Vascularization of the Cornea

Purpose

We sought to identify the anti-angiogenic molecule expressed in corneal keratocytes that is responsible for maintaining the avascularity of the cornea.

Methods

Human umbilical vein endothelial cells (HUVECs) were cultured with either human dermal fibroblasts or with human corneal keratocytes under serum-free conditions. The areas that exhibited blood vessel formation were estimated by immunostaining the cultures with an antitibody against CD31, a blood vessel marker. We also performed microarray gene-expression analysis and selected one molecule, angiopoietin-like 7 (ANGPTL7) for further functional studies conducted with the keratocytes and in vivo in mice.

Results

Areas showing blood vessel formation in normal serum-free medium were conditions were markedly smaller when HUVECs were co-cultured with corneal keratocytes than when they were co-cultured with the dermal fibroblasts under the same conditions. Microarray analysis revealed that ANGPTL7 expression was higher in keratocytes than in dermal fibroblasts. In vitro, inhibiting ANGPTL7 expression by using a specific siRNA led to greater tube formation than did the transfection of cells with a control siRNA, and this increase in tube formation was abolished when recombinant ANGPTL7 protein was added to the cultures. In vivo, intrastromal injections of an ANGPTL7 PshRNA into the avascular corneal stroma of mice resulted in the growth of blood vessels.

Conclusions

ANGPTL7, which is abundantly expressed in keratocytes, plays a major role in maintaining corneal avascularity and transparency.     

High Frequency of Haplotype HLA-DQ7 in Celiac Disease Patients from South Italy: Retrospective Evaluation of 5,535 Subjects at Risk of Celiac Disease

Background

Celiac disease (CD) has a strong genetic component mainly due to HLA DQ2/DQ8 encoding genes. However, a minority of CD patients are DQ2/DQ8-negative. To address this issue, we retrospectively characterized HLA haplotypes in 5,535 subjects at risk of CD (either relatives of CD patients or subjects with CD-like symptoms) referred to our center during a 10-year period.

Methods

We identified loci DQA1/DQB1/DRB1 by sequence-specific oligonucleotide-PCR and sequence-specific primer-PCR; anti-transglutaminase IgA/IgG and anti-endomysium IgA by ELISA and indirect immunofluorescence, respectively.

Results

We diagnosed CD in 666/5,535 individuals, 4.2% of whom were DQ2/DQ8-negative. Interestingly, DQ7 was one of the most abundant haplotypes in all CD patients and significantly more frequent in DQ2/DQ8-negative (38%) than in DQ2/DQ8-positive CD patients (24%) (p<0.05).

Conclusion

Our data lend support to the concept that DQ7 represents an additive or independent CD risk haplotype with respect to DQ2/DQ8 haplotypes but this finding should be verified in other large CD populations.     

Negative Interference in Serum HBsAg ELISA from Rheumatoid Factors

Background

RF(Rheumatoid factor) is usually thought to cause positive interference in immunoassay. Recently, our study showed that high-concentration RFs caused negative interference as well as positive interference in serum HBsAg(Hepatitis B surface antigen) ELISA(Enzyme-linked immunosorbent assay), but it is unclear that RF causing negative interference is an anomaly produced by a certain ELISA kit or a common property of most of HBsAg ELISA kits.

Methods

Serum models were made by blending HBsAg-positive sera and high- or moderate-concentration RFs sera at the ratio of 1: 9, then one-step and two-step ELISA were adopted to determine HBsAg in serum models.

Results

No matter what kind of kit used, one-step ELISA showed that HBsAg S/CO( sample/cut off) values in serum models were significantly lower than original values. Bivariate correlations tests showed decline rates of HBsAg S/CO Values were not associated to serum RF concentrations ranging from 288 to 3560 IU/mL. HBsAg converted to be negative in 69.80% serum models with original-value ranging from 1.00 to 10.00, and in 2.68% serum models with higher original-value. RF causing decline of HBsAg S/CO value provided by one-step ELISA was more obvious than that provided by two-step ELISA.

Conclusions

It is concluded that susceptibility of all HBsAg ELISA assays to interference from RF, leading to predominantly lower and in some cases "false-negative" results, and moreover, the lower the original HBsAg S/CO Value, the higher the false-negative rate.     

Macrophage Activation in Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Background

Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) is a common cause of disease acceleration in IPF and has a major impact on mortality. The role of macrophage activation in AE of IPF has never been addressed before.

Methods

We evaluated BAL cell cytokine profiles and BAL differential cell counts in 71 IPF patients w/wo AE and in 20 healthy volunteers. Twelve patients suffered from AE at initial diagnosis while sixteen patients developed AE in the 24 months of follow-up. The levels of IL-1ra, CCL2, CCL17, CCL18, CCL22, TNF-α, IL-1β, CXCL1 and IL-8 spontaneously produced by BAL-cells were analysed by ELISA.

Results

In patients with AE, the percentage of BAL neutrophils was significantly increased compared to stable patients. We found an increase in the production rate of the pro-inflammatory cytokines CXCL1 and IL-8 combined with an increase in all tested M2 cytokines by BAL-cells. An increase in CCL18 levels and neutrophil counts during AE was observed in BAL cells from patients from whom serial lavages were obtained. Furthermore, high baseline levels of CCL18 production by BAL cells were significantly predictive for the development of future AE.

Conclusions

BAL cell cytokine production levels at acute exacerbation show up-regulation of pro-inflammatory as well as anti-inflammatory/ M2 cytokines. Our data suggest that AE in IPF is not an incidental event but rather driven by cellular mechanisms including M2 macrophage activation.     

Differences in the Triglyceride to HDL-Cholesterol Ratio between Palestinian and Israeli Adults

Aims

To evaluate differences in the triglyceride to HDL-cholesterol ratio (TG/HDL), thought to be a proxy measure of insulin resistance, between Palestinian and Israeli adults in view of the greater incidence of coronary heart disease and high prevalence of diabetes in Palestinian Arabs.

Research Methods

A population-based observational prevalence study of cardiovascular and diabetes risk factors in Jerusalem. Participants (968 Palestinians, 707 Israelis, sampled at ages 25-74 years) underwent fasting and 2h post-75g oral challenge plasma glucose determinations. Metabolic risk was assessed using the surrogate index TG/HDL. Sex-specific comparisons were stratified by categories of body mass index and sex-specific waist circumference quartiles, adjusted by regression for age, glucose tolerance status and use of statins.

Results

Prevalence of overweight and obesity was substantially larger in Palestinians (p = 0.005). Prevalence of diabetes was 2.4 and 4 fold higher among Palestinian men and women, respectively (p<0.001). Adjusted TG/HDL was higher in Palestinians than Israelis across BMI and waist circumference categories (p<0.001 for both). Higher TG/HDL in Palestinians persisted in analyses restricted to participants with normal glucose tolerance and off statins. Notably, higher TG/HDL among Palestinians prevailed at a young age (25-44 years) and in normal weight individuals of both sexes.

Conclusions

Palestinians have a higher TG/HDL ratio than Israelis. Notably, this is evident also in young, healthy and normal weight participants. These findings indicate the need to study the determinants of this biomarker and other measures of insulin resistance in urban Arab populations and to focus research attention on earlier ages: childhood and prenatal stages of development.     

Increased B Cell and Cytotoxic NK Cell Proportions and Increased T Cell Responsiveness in Blood of Natalizumab-Treated Multiple Sclerosis Patients

Background

Changes in the blood lymphocyte composition probably both mediate and reflect the effects of natalizumab treatment in multiple sclerosis, with implications for treatment benefits and risks.

Methods

A broad panel of markers for lymphocyte populations, including states of activation and co-stimulation, as well as functional T cell responses to recall antigens and mitogens, were assessed by flow cytometry in 40 patients with relapsing multiple sclerosis before and after one-year natalizumab treatment.

Results

Absolute numbers of all major lymphocyte populations increased after treatment, most markedly for NK and B cells. The fraction of both memory and presumed regulatory B cell subsets increased, as did CD3^-CD56^dim cytotoxic NK cells, whereas CD3^-CD56^bright regulatory NK cells decreased. The increase in cell numbers was further associated with a restored T cell responsiveness to recall antigens and mitogens in functional assays.

Conclusions

Our data confirms that natalizumab treatment increases the number of lymphocytes in blood, likely mirroring the expression of VLA-4 being highest on NK and B cells. This finding supports reduction of lymphocyte extravasation as a main mode of action, although the differential effects on subpopulation composition suggests that cell-signalling may also be affected. The systemic increase in T cell responsiveness reflects the increase in numbers, and while augmenting anti-infectious responses systemically, localized responses may become correspondingly decreased.     

Rhinovirus-16 Induced Release of IP-10 and IL-8 Is Augmented by Th2 Cytokines in a Pediatric Bronchial Epithelial Cell Model

Background

In response to viral infection, bronchial epithelial cells increase inflammatory cytokine release to activate the immune response and curtail viral replication. In atopic asthma, enhanced expression of Th2 cytokines is observed and we postulated that Th2 cytokines may augment the effects of rhinovirus-induced inflammation.

Methods

Primary bronchial epithelial cell cultures from pediatric subjects were treated with Th2 cytokines for 24 h before infection with RV16. Release of IL-8, IP-10 and GM-CSF was measured by ELISA. Infection was quantified using RTqPCR and TCID₅₀. Phosphatidyl inositol 3-kinase (PI3K) and P38 mitogen activated protein kinase (MAPK) inhibitors and dexamethasone were used to investigate differences in signaling pathways.

Results

The presence of Th2 cytokines did not affect RV replication or viral titre, yet there was a synergistic increase in IP-10 release from virally infected cells in the presence of Th2 cytokines. Release of IL-8 and GM-CSF was also augmented. IP-10 release was blocked by a PI3K inhibitor and IL-8 by dexamethasone.

Conclusion

Th2 cytokines increase release of inflammatory cytokines in the presence of rhinovirus infection. This increase is independent of effects of virus replication. Inhibition of the PI3K pathway inhibits IP-10 expression.     

MicroRNA-26a Inhibits Angiogenesis by Down-Regulating VEGFA through the PIK3C2α/Akt/HIF-1α Pathway in Hepatocellular Carcinoma

Background & Aims

microRNAs (miRNAs) have been reported to regulate angiogenesis by down-regulating the expression of pro-angiogenic or anti-angiogenic factors. The aims of this study were to investigate whether miR-26a inhibited angiogenesis by down-regulating vascular endothelial growth factor A (VEGFA) and its clinical relevance in hepatocellular carcinoma (HCC).

Methods

The expression of miR-26a was modified in HepG2 and HCCLM3 cell lines respectively, and a panel of angiogenic factors was measured by real-time PCR in the cells. A luciferase reporter assay was used to validate the target gene of miR-26a. Specific inhibitors of signal transduction pathway and siRNA approaches were used to explore the regulatory mechanism of miR-26a. Migration and tube forming assays were conducted to show the changes of angiogenesis induced by miR-26a and its target genes. Finally animal studies were used to further validate those findings.

Results

Ectopic expression of miR-26a exhibited decreased levels of VEGFA in HepG2 cells. Migration and tube forming of human umbilical vein endothelial cells (HUVECs) were decreased in the conditioned medium from ectopic expression of miR-26a in HepG2 cells compared to control HepG2 cells. The pro-angiogenic effects of the conditioned medium of HepG2 cells on HUVECs were specifically decreased by LY294002, YC-1, and bevacizumab. Integrated analysis disclosed PIK3C2α as a downstream target gene of miR-26a. Ectopic expression of miR-26a suppressed ectopic and orthotopic tumor growth and vascularity in nude mice. The results in HCCLM3 were consistent with those in HepG2. miR-26a expression was inversely correlated with VEGFA expression in HCC patients.

Conclusions

miR-26a modulated angiogenesis of HCC through the PIK3C2α/Akt/HIF-1α/VEGFA pathway. The expression of VEGFA was inversely correlated with miR-26a expression in HCC tumors.     

Visfatin as a Novel Mediator Released by Inflamed Human Endothelial Cells

Background

Visfatin is a multifaceted adipokine whose circulating levels are enhanced in different metabolic diseases. Extracellular visfatin can exert various deleterious effects on vascular cells, including inflammation and proliferation. Limited evidence exists, however, on the capacity of human vascular cells to synthesize and release visfatin by themselves, under basal or pro-inflammatory conditions.

Methods and Results

Intracellular visfatin was detected by Western blot in non-stimulated human umbilical vein endothelial cells (HUVEC). However, exposing HUVEC for 18 h to a series of pro-inflammatory stimulus, such as interleukin (IL)-1β (1 to 10 ng/mL), tumor necrosis factor-α (1 to 10 ng/mL) or angiotensin II (10 pmol/L to 1 μmol/L) markedly enhanced intracellular visfatin content. Using IL-1β (10 ng/mL; 18 h), it was determined that the increase in intracellular visfatin, which was paralleled by enhanced visfatin mRNA levels, relied on a signalling mechanism involving both nuclear factor-κB and poly (ADP ribose) polymerase-1 activation. Moreover, IL-1β modified the sub-cellular localization of visfatin; while in non-stimulated HUVEC immunoreactive visfatin predominantly showed an intra-nuclear granular pattern, in IL-1β-inflamed cells an extra-nuclear filamentous staining, co-localising with F-actin fibers and suggesting a secretory pattern, was mainly found. Indeed, IL-1β promoted visfatin secretion, as determined by both ELISA and immunocytochemistry.

Conclusions

Human endothelial cells synthesize and release visfatin, particularly in response to inflammation. We suggest that the inflamed endothelium can be a source of visfatin, which arises as a local inflammatory mediator and a potential therapeutic target to interfere with vascular inflammation.     

Extracellular Vesicles from Leishmania-Infected Macrophages Confer an Anti-infection Cytokine-Production Profile to Na?ve Macrophages

Background

Extracellular vesicles (EVs) are structures with phospholipid bilayer membranes and 100–1000 nm diameters. These vesicles are released from cells upon activation of surface receptors and/or apoptosis. The production of EVs by dendritic cells, mast cells, macrophages, and B and T lymphocytes has been extensively reported in the literature. EVs may express MHC class II and other membrane surface molecules and carry antigens. The aim of this study was to investigate the role of EVs from Leishmania-infected macrophages as immune modulatory particles.

Methodology/Principal Findings

In this work it was shown that BALB/c mouse bone marrow-derived macrophages, either infected in vitro with Leishmania amazonensis or left uninfected, release comparable amounts of 50–300 nm-diameter extracellular vesicles (EVs). The EVs were characterized by flow cytometry and electron microscopy. The incubation of naïve macrophages with these EVs for 48 hours led to a statistically significant increase in the production of the cytokines IL-12, IL-1β, and TNF-α.

Conclusions/Significance

EVs derived from macrophages infected with L. amazonensis induce other macrophages, which in vivo could be bystander cells, to produce the proinflammatory cytokines IL-12, IL-1β and TNF-α. This could contribute both to modulate the immune system in favor of a Th1 immune response and to the elimination of the Leishmania, leading, therefore, to the control the infection.     

Investigating Thought Disorder in Schizophrenia: Evidence for Pathological Activation

Background

Previous research has yielded evidence for enhanced semantic priming in formal thought-disordered schizophrenia patients, a result that fits well with the hypothesis of disinhibited processes of spreading activation in this population.

Objective

The current study examined whether hyper priming among schizophrenia patients is an outcome of further spreading of activation of a node or a result of farther activation of nodes in the semantic network. We also try to shed light on the fate of this activation.

Methods

The present study tested this hypothesis by using semantic and identical priming in two different experiments. SOA (stimulus onset asynchrony) was manipulated (240 ms vs. 740 ms) within block. It is assumed that among healthy individuals, performance relies on a balance between activation and inhibition processes, contrary to in schizophrenic individuals. In order to examine this hypothesis, we compared formal thought-disordered schizophrenia patients, non thought-disordered schizophrenia patients, and healthy controls.

Results

For thought-disordered schizophrenia patients, we found a large positive semantic effect and identical priming effect (129 ms and 154 ms, respectively) only with short SOA. SOA and type of priming did not modulate priming effects in the control groups.

Conclusions

This result supports the claim that there is a lack of inhibitory processes among thought-disordered patients. Hyper priming in the thought-disorder group may be an outcome of hyper activation followed by rapid decay below baseline threshold.     

An Exposure to the Oxidized DNA Enhances Both Instability of Genome and Survival in Cancer Cells

Background

Cell free DNA (cfDNA) circulates throughout the bloodstream of both healthy people and patients with various diseases and acts upon the cells. Response to cfDNA depends on concentrations and levels of the damage within cfDNA. Oxidized extracellular DNA acts as a stress signal and elicits an adaptive response.

Principal Findings

Here we show that oxidized extracellular DNA stimulates the survival of MCF-7 tumor cells. Importantly, in cells exposed to oxidized DNA, the suppression of cell death is accompanied by an increase in the markers of genome instability. Short-term exposure to oxidized DNA results in both single- and double strand DNA breaks. Longer treatments evoke a compensatory response that leads to a decrease in the levels of chromatin fragmentations across cell populations. Exposure to oxidized DNA leads to a decrease in the activity of NRF2 and an increase in the activity of NF-kB and STAT3. A model that describes the role of oxidized DNA released from apoptotic cells in tumor biology is proposed.

Conclusions/Significance

Survival of cells with an unstable genome may substantially augment progression of malignancy. Further studies of the effects of extracellular DNA on malignant and normal cells are warranted.