Chronic Trypanosoma cruzi infection activates the TWEAK/Fn14 axis in cardiac myocytes and fibroblasts driving structural and functional changes that affect the heart.

Sustained interaction between the cytokine tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its functional receptor, fibroblast growth factor-inducible 14 (Fn14), has been linked to cardiovascular disorders. Chagas cardiomyopathy, elicited by Trypanosoma cruzi infection, is associated with chronic inflammation, fibrosis and hypertrophy. This study aimed to explore the involvement of the TWEAK/Fn 14 axis in development of Chagas heart disease. Parasite infection in vitro triggered Fn14 overexpression in atrial HL-1 myocytes and cardiac MCF fibroblasts. Fn14 levels were also increased in heart tissue from C57BL/6 mice at 130 days post-infection, particularly in myocytes and fibroblasts. Concurrently, TWEAK expression in circulating monocytes from this group was higher than that determined in uninfected controls. TWEAK/Fn14 interaction was functional in myocytes and fibroblasts isolated from infected hearts, leading to TNF receptor-associated factor 2 (TRAF2)-mediated activation of nuclear factor kappa B (NFκB) signaling. Ex vivo stimulation of both cell types with recombinant TWEAK for 24 h boosted the NFκB-regulated production of proinflammatory/profibrotic mediators (IL-1ß, IL-6, TNF-α, IL-8, CCL2, CCL5, MMP-2, MMP-9, ICAM-1, E-selectin) involved in chronic T. cruzi cardiomyopathy. We further evaluated the therapeutic potential of the soluble decoy receptor Fn14-Fc to interfere with TWEAK/Fn14-dependent pathogenic activity. Fn14-Fc treatment of chronically infected mice was effective in neutralizing the ligand and reverting electrocardiographic abnormalities, maladaptive inflammation, adverse remodeling and hypertrophy in myocardium. Altogether, these findings suggest that sustained TWEAK/Fn14 induction by persistent T. cruzi infection is implicated in cardiopathogenesis and make TWEAK/Fn14 axis a promising target for the treatment of chronic Chagas heart disease.

The combined action of glycoinositolphospholipid from Trypanosoma cruzi and macrophage migration inhibitory factor increases proinflammatory mediator production by cardiomyocytes and vascular endothelial cells.

Cardiomyopathy is the most serious complication of chronic Chagas disease, caused by infection with the protozoan Trypanosoma cruzi. Exacerbated inflammation of the myocardium constitutes a major pathologic component of the disease. In the myocardial microenvironment, parasite antigens and host inflammatory mediators may aggravate tissue damage. The glycoinositolphospholipid (GIPL) from T. cruzi is an inflammation-eliciting antigen recognized by Toll-like receptor 4 (TLR4), whereas the proinflammatory cytokine macrophage migration inhibitory factor (MIF) promotes progression of chronic Chagas cardiomyopathy. We herein aimed to examine the involvement of GIPL and MIF in molecular mechanisms leading to a pathogenic inflammatory response in HL-1 cardiomyocytes and HMEC microvascular endothelial cells. Immunofluorescence analysis revealed that GIPL enhanced TLR4 expression in both cell types. We found that TLR4/GIPL interaction and MIF activity modulated the arachidonic acid pathway implicated in persistent inflammation. The combination of GIPL at 50 µg/ml and MIF at 50 ng/ml upregulated type 2 cyclooxygenase (COX-2) levels in HL-1 and HMEC cells, in a stronger way than each molecule acting independently. Moreover, increased expression of prostanoid synthases and release of prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) were detected in stimulated cells. Transfection experiments in HL-1 and HMEC cells showed that COX-2 induction was transcriptionally regulated through GIPL-TLR4 engagement and NFκB signaling cascade. (GIPL + MIF)-triggered NFκB activation was markedly attenuated by treatment with 100 µM Fenofibrate, a PPAR-α ligand. Fenofibrate reduced COX-2-dependent generation of bioactive lipids in HL-1 and HMEC cells. In addition, Fenofibrate abolished (GIPL + MIF)-fostered release of NO, IL-1ß, IL-6, TNF-α, and CCL2. The combined actions of GIPL and MIF display potential for amplifying the inflammatory response in myocardium of parasite-infected hosts. Our current findings might help develop more effective measures to ameliorate cardiovascular abnormalities associated with Chagas heart disease.

Machine Learning Models and Multiparametric Magnetic Resonance Imaging for the Prediction of Pathologic Response to Neoadjuvant Chemotherapy in Breast Cancer.

BACKGROUND: Most breast cancer (BC) patients fail to achieve pathological complete response (pCR) after neoadjuvant chemotherapy (NAC). The aim of this study was to evaluate whether imaging features (perfusion/diffusion imaging biomarkers + radiomic features) extracted from pre-treatment multiparametric (mp)MRIs were able to predict, alone or in combination with clinical data, pCR to NAC. METHODS: Patients with stage II-III BC receiving NAC and undergoing breast mpMRI were retrospectively evaluated. Imaging features were extracted from mpMRIs performed before NAC. Three different machine learning models based on imaging features, clinical data or imaging features + clinical data were trained to predict pCR. Confusion matrices and performance metrics were obtained to assess model performance. Statistical analyses were conducted to evaluate differences between responders and non-responders. RESULTS: Fifty-eight patients (median [range] age, 52 [45-58] years) were included, of whom 12 showed pCR. The combined model improved pCR prediction compared to clinical and imaging models, yielding 91.5% of accuracy with no false positive cases and only 17% false negative results. Changes in different parameters between responders and non-responders suggested a possible increase in vascularity and reduced tumour heterogeneity in patients with pCR, with the percentile 25th of time-to-peak (TTP), a classical perfusion parameter, being able to discriminate both groups in a 75% of the cases. CONCLUSIONS: A combination of mpMRI-derived imaging features and clinical variables was able to successfully predict pCR to NAC. Specific patient profiles according to tumour vascularity and heterogeneity might explain pCR differences, where TTP could emerge as a putative surrogate marker for pCR.

Trypanosoma cruzi down-regulates adiponectin expression in mouse adipocytes via the NFAT signaling pathway.

Upon infection by Trypanosoma cruzi, adipocytes adopt a clearly defined inflammatory phenotype with concomitant down-regulation of adiponectin expression, which influences the pathogenesis of Chagas heart disease. Herein, we examined how T. cruzi interferes with transcriptional regulation of adiponectin production in mouse adipocytes. The invading pathogen activates the Ca2+/calcineurin/NFATc4 signaling pathway in 3T3-L1 cells. Parasite-induced early activation of NFATc4 is involved in repressing adiponectin expression through recognition of the specific response element located at (-363 to -344) of the gene promoter. Nuclear import of dephosphorylated NFATc4 and decreased adiponectin levels were further demonstrated in white adipose tissue from acutely infected mice. Our current findings point to better clarify the complex role of adipose tissue in the modulation of inflammatory mechanisms operative during T. cruzi infection.

Dual chemotherapy with benznidazole at suboptimal dose plus curcumin nanoparticles mitigates Trypanosoma cruzi-elicited chronic cardiomyopathy.

Curcumin (Cur) is a natural polyphenolic flavonoid isolated from the rhizomes of Curcuma longa. Its anti-inflammatory and cardioprotective properties are increasingly considered to have beneficial effects on the progression of cardiomyopathy associated with Chagas disease, caused by Trypanosoma cruzi. However, the Cur therapeutic limitation is its bioavailability and new Cur nanomedicine formulations are developed to overcome this obstacle. In this research, we provide evidence showing that oral therapy with a suboptimal dose of the standard parasiticidal drug benznidazole (BZ) in combination with Cur-loaded nanoparticles is capable of reducing myocardial parasite load, cardiac hypertrophy, inflammation and fibrosis in mice with long-term infection by T. cruzi. Treatment with BZ plus Cur was highly effective in downregulating myocardial expression of proinflammatory cytokines/chemokines (IL-1ß, TNF-α, IL-6, CCL5), and the level/activity of matrix metalloproteinases (MMP-2, MMP-9) and inducible enzymes (cyclooxygenase, nitric oxide synthase) implicated in leukocyte recruitment and cardiac remodeling. Oral administration of a Cur-based nanoformulation displays potential as a complementary strategy to the conventional BZ chemotherapy in the treatment of chronic Chagas heart disease.

Curcumin exerts anti-inflammatory and vasoprotective effects through amelioration of NFAT-dependent endothelin-1 production in mice with acute Chagas cardiomyopathy.

BACKGROUND: The anti-inflammatory and cardioprotective properties of curcumin (Cur), a natural polyphenolic flavonoid isolated from the rhizomes of Curcuma longa, are increasingly considered to have beneficial effects on the progression of Chagas heart disease, caused by the protozoan parasite Trypanosoma cruzi. OBJECTIVE: To evaluate the effects of oral therapy with Cur on T. cruzi-mediated cardiovasculopathy in acutely infected mice and analyse the in vitro response of parasite-infected human microvascular endothelial cells treated with this phytochemical. METHODS: Inflammation of heart vessels from Cur-treated and untreated infected mice were analysed by histology, with benznidazole (Bz) as the reference compound. Parasitaemia was monitored by the direct method. Capillary permeability was visualised by Evans-blue assay. Myocardial ET-1, IL-6, and TNF-α mRNA expressions were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Microvascular endothelial HMEC-1 cells were infected in vitro with or without addition of Cur or Bz. Induction of the Ca2+/NFAT pathway was assessed by fluorometry, immunoblotting, and reporter assay. FINDINGS: Oral Cur therapy of recently infected mice reduced inflammatory cell infiltration of myocardial arteries without lowering parasite levels. Compared to that of the phosphate-buffered saline-receiving group, hearts from Cur-treated mice showed significantly decreased vessel inflammation scores (p < 0.001), vascular permeabilities (p < 0.001), and levels of IL-6/TNF-α (p < 0.01) and ET-1 (p < 0.05) mRNA. Moreover, Cur significantly (p < 0.05 for transcript; p < 0.01 for peptide) downregulated ET-1 secretion from infected HMEC-1 cells. Remarkably, Cur addition significantly (p < 0.05 at 27.0 µM) interfered with T. cruzi-dependent activation of the Ca2+/NFATc1 signalling pathway that promotes generation of inflammatory agents in HMEC-1 cells. CONCLUSIONS: Oral treatment with Cur dampens cardiovasculopathy in acute Chagas mice. Cur impairs the Ca2+/NFATc1-regulated release of ET-1 from T. cruzi-infected vascular endothelium. These findings identify new perspectives for exploring the potential of Cur-based interventions to ameliorate Chagas heart disease.

Endogenous osteopontin induces myocardial CCL5 and MMP-2 activation that contributes to inflammation and cardiac remodeling in a mouse model of chronic Chagas heart disease.

Cardiac dysfunction with progressive inflammation and fibrosis is a hallmark of Chagas disease caused by persistent Trypanosoma cruzi infection. Osteopontin (OPN) is a pro-inflammatory cytokine that orchestrates mechanisms controlling cell recruitment and cardiac architecture. Our main goal was to study the role of endogenous OPN as a modulator of myocardial CCL5 chemokine and MMP-2 metalloproteinase, and its pathological impact in a murine model of Chagas heart disease. Wild-type (WT) and OPN-deficient (spp1 -/-) mice were parasite-infected (Brazil strain) for 100days. Both groups developed chronic myocarditis with similar parasite burden and survival rates. However, spp1 -/- infection showed lower heart-to-body ratio (P<0.01) as well as reduced inflammatory pathology (P<0.05), CCL5 expression (P<0.05), myocyte size (P<0.05) and fibrosis (P<0.01) in cardiac tissues. Intense OPN labeling was observed in inflammatory cells recruited to infected heart (P<0.05). Plasma concentration of MMP-2 was higher (P<0.05) in infected WT than in spp1 -/- mice. Coincidently, specific immunostaining revealed increased gelatinase expression (P<0.01) and activity (P<0.05) in the inflamed hearts from T. cruzi WT mice, but not in their spp1 -/- littermates. CCL5 and MMP-2 induction occurred preferentially (P<0.01) in WT heart-invading CD8+ T cells and was mediated via phospho-JNK MAPK signaling. Heart levels of OPN, CCL5 and MMP-2 correlated (P<0.01) with collagen accumulation in the infected WT group only. Endogenous OPN emerges as a key player in the pathogenesis of chronic Chagas heart disease, through the upregulation of myocardial CCL5/MMP-2 expression and activities resulting in pro-inflammatory and pro-hypertrophic events, cardiac remodeling and interstitial fibrosis.

Curcumin exerts anti-inflammatory and vasoprotective effects through amelioration of NFAT-dependent endothelin-1 production in mice with acute Chagas cardiomyopathy

BACKGROUND The anti-inflammatory and cardioprotective properties of curcumin (Cur), a natural polyphenolic flavonoid isolated from the rhizomes of Curcuma longa, are increasingly considered to have beneficial effects on the progression of Chagas heart disease, caused by the protozoan parasite Trypanosoma cruzi. OBJECTIVE To evaluate the effects of oral therapy with Cur on T. cruzi-mediated cardiovasculopathy in acutely infected mice and analyse the in vitro response of parasite-infected human microvascular endothelial cells treated with this phytochemical. METHODS Inflammation of heart vessels from Cur-treated and untreated infected mice were analysed by histology, with benznidazole (Bz) as the reference compound. Parasitaemia was monitored by the direct method. Capillary permeability was visualised by Evans-blue assay. Myocardial ET-1, IL-6, and TNF-α mRNA expressions were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Microvascular endothelial HMEC-1 cells were infected in vitro with or without addition of Cur or Bz. Induction of the Ca2+/NFAT pathway was assessed by fluorometry, immunoblotting, and reporter assay. FINDINGS Oral Cur therapy of recently infected mice reduced inflammatory cell infiltration of myocardial arteries without lowering parasite levels. Compared to that of the phosphate-buffered saline-receiving group, hearts from Cur-treated mice showed significantly decreased vessel inflammation scores (p < 0.001), vascular permeabilities (p < 0.001), and levels of IL-6/TNF-α (p < 0.01) and ET-1 (p < 0.05) mRNA. Moreover, Cur significantly (p < 0.05 for transcript; p < 0.01 for peptide) downregulated ET-1 secretion from infected HMEC-1 cells. Remarkably, Cur addition significantly (p < 0.05 at 27.0 μM) interfered with T. cruzi-dependent activation of the Ca2+/NFATc1 signalling pathway that promotes generation of inflammatory agents in HMEC-1 cells. CONCLUSIONS Oral treatment with Cur dampens cardiovasculopathy in acute Chagas mice. Cur impairs the Ca2+/NFATc1-regulated release of ET-1 from T. cruzi-infected vascular endothelium. These findings identify new perspectives for exploring the potential of Cur-based interventions to ameliorate Chagas heart disease.

Partially coherent diffraction-free vortex beams with a Bessel-mode structure.

A new family of partially coherent beams carrying optical vortices is introduced. Any member of this family represents an incoherent superposition of fully coherent orthogonal Bessel modes with the same helical wavefront and is notable for its diffraction-free propagation. It is shown analytically and experimentally that such beams can be approximately generated in the Fourier-transforming optical system with a computer-controlled liquid-crystal spatial light modulator.

Unmethylated CpG motifs in Toxoplasma gondii DNA induce TLR9- and IFN-ß-dependent expression of α-defensin-5 in intestinal epithelial cells.

The gut epithelial barrier is a strategic place to prevent, or at least to limit, parasite dissemination upon oral infection with Toxoplasma gondii. Innate immunity to this pathogen results from delicate interactions involving different components of the infecting agent and the host. We herein aimed to examine the molecular mechanism by which protozoan DNA boosts the production of α-defensin-5 (DEFA-5), the main antimicrobial peptide at the target site of infection. The present study shows that DEFA-5 is rapidly upregulated in intestinal epithelial cells following intracellular Toll-like receptor 9 (TLR9) activation by unmethylated CpG motifs in DNA from T. gondii (CpG-DNA). Concomitantly, CpG-DNA purified from the pathogen markedly increased TLR9 mRNA expression levels in the Caco-2 cell line. We further verified that DEFA-5 production was dependent on interferon-ß released from these cells upon treatment with CpG-DNA prepared from tachyzoites. Our results suggest that, in protozoan DNA-stimulated intestinal epithelial cells, the TLR9/interferon-ß/DEFA-5 pathway may initiate an innate anti-T. gondii response without the need of parasite invasion. These findings highlight the key role of the gut epithelium in Toxoplasma recognition and amplification of local host defence against this microbe, thereby contributing to gain insight into immunoprotective mechanisms and to improve therapeutic strategies.

Osteopontin-dependent regulation of Th1 and Th17 cytokine responses in Trypanosoma cruzi-infected C57BL/6 mice.

Osteopontin (OPN) is a multifunctional protein participating in the regulation of different Th cell lineages and critically involved in the initiation of immune responses to diverse pathogens. Our study goal was to verify whether OPN helps modulate the protective Th1 and Th17 cytokine responses in C57BL/6 mice infected with Trypanosoma cruzi, the etiological agent of Chagas disease. Parasite infection induced OPN release from murine macrophages in vitro and acute Chagas mice displayed enhanced serum levels of this cytokine at the peak of parasitemia. Upon administration of a neutralizing anti-OPN antibody, recently infected mice presented lower Th1 and Th17 responses, increased parasitemia and succumbed earlier and at higher rates to infection than non-immune IgG-receiving controls. The anti-OPN therapy also resulted in reduced circulating levels of IL-12 p70, IFN-γ, IL-17A and specific IgG(2a) antibodies. Furthermore, antibody-mediated blockade of OPN activity abrogated the ex vivo production of IL-12 p70, IFN-γ and IL-17A, while promoting IL-10 secretion, by spleen macrophages and CD4(+) T cells from T. cruzi-infected mice. Th1 and Th17 cytokine release induced by OPN preferentially involved the α(v)ß(3) integrin OPN receptor, whereas concomitant down-modulation of IL-10 production would mostly depend on OPN interaction with CD44. Our findings suggest that, in resistant C57BL/6 mice, elicitation of protective Th1 and Th17 cytokine responses to T. cruzi infection is likely to be regulated by endogenous OPN.

Effect of coherence and polarization on frequency resolution in optical Fourier transforming system.

Using an example of vector Gaussian Schell-model beam, we demonstrate and analyze the dependence of the spatial frequency resolution in optical Fourier transforming system on the intrinsic coherence-polarization structure of illumination.

Effect of coherence and polarization on resolution of optical imaging system.

The effect of coherence properties of illumination on image resolution, well known in a scalar case, is studied for the case of vector electromagnetic illumination. Using an example of vector Gaussian Schell-model illumination, we analyze the dependence of optical system resolution on the transverse correlation lengths of the orthogonal field components and on the ratio of the powers of these components, each taken separately.

Experimental generating the partially coherent and partially polarized electromagnetic source.

The technique for generating the partially coherent and partially polarized source starting from the completely coherent and completely polarized laser source is proposed and analyzed. This technique differs from the known ones by the simplicity of its physical realization. The efficiency of the proposed technique is illustrated with the results of physical experiment in which an original technique for characterizing the coherence and polarization properties of the generated source is employed.

Factores asociados con la no realizacion de la prueba de la tuberculina en una cohorte de pacientes VIH positivos / Factors related to non-prescription of tuberculin skin testing in a cohort of HIV-infected people

Introduccion Dada la asociacion entre tuberculosis (TB) e infeccion por VIH, la realizacion del Mantoux esta indicada en todo paciente infectado con VIH. Este articulo analiza la frecuencia de no realizacion de la prueba de la tuberculina y sus factores asociados en una cohorte de infectados con VIH. Pacientes y metodos Entre 2000-C2002 se identifico en 10 hospitales a todos los pacientes infectados con VIH y no seguidos previamente, de forma regular, en consultas especificas. Se recogio informacion de la historia clinica sobre realizacion del Mantoux y otras variables. Se calculo el porcentaje de no realizacion del Mantoux y los factores asociados mediante la utilizacion como medida de asociacion de la odds ratio (OR) y su intervalo de confianza (IC) del 95%. Para el analisis multivariante se ajusto un modelo de regresion logistica. Resultados Mil doscientos cuarenta y dos pacientes cumplieron criterios de inclusion y a 185 pacientes no se les realizo el Mantoux (el 17,6% de aquellos en los que estaba indicado). La probabilidad de no realizacion del Mantoux fue mayor en usuarios de drogas (OR: 2,6; IC del 95%: 1,1¨C6,5) y menor entre los desempleados (OR: 0,6; IC del 95%: 0,3¨C1,0), aquellos con mas de 200 CD4 (CD4 200¨C499: OR: 0,5; IC del 95%: 0,3¨C0,9; CD4 ¡Ý500: OR: 0,3; IC del 95%: 0,2¨C0,6) y los contactos con enfermos tuberculosos (OR: 0,2; IC del 95%: 0,1¨C0,5).ConclusionesEl porcentaje de no realizacion del Mantoux es bastante elevado. La no realizacion del Mantoux parece asociarse con las expectativas del medico, tanto sobre el resultado de la prueba como sobre la correcta cumplimentacion del tratamiento preventivo anti-TB por el paciente ( AU)

Introduction Tuberculin skin testing (TST) for tuberculosis (TB) is recommended for all patients with HIV infection because of the known relationship between these two conditions. In this report we analyze the incidence and variables associated with non-prescription of TST in a cohort of HIV-infected people. Patients and methods Longitudinal study conducted between 2000 and 2002 at 10 HIV hospital-based clinics. All HIV-infected patients who had not been regularly followed-up previously in dedicated clinics were identified. Data about TST and other variables related to TB were obtained from the clinical records. We calculated the percentage of patients who did not undergo TST and the associated factors, using odds ratios (ORs) and the 95% CI to investigate associations. A multivariate logistic regression analysis was performed. Results A total of 1242 patients met the inclusion criteria. TST was not performed in 185 patients (17.6% of those eligible). The fact of being an intravenous drug abuser was associated with a higher probability of TST non-prescription (OR: 2.6, 95% CI 1.1¨C6.5), whereas being unemployed (OR: 0.6, 95% CI 0.3¨C1.0), having a CD4 cell count >200 (CD4 200¨C499: OR 0.5, 95% CI 0.3¨C0.9. CD4¡Ý500: OR 0.3, 95% CI 0.2¨C0.6), and contact with persons with TB (OR 0.2, 95% CI 0.1¨C0.5) were associated with a lower probability. ConclusionsIn this study, the percentage of TST non-prescription was quite high. The results suggest that TST non-prescription in this population is related to the clinicians¡¯ expectations regarding the results of the test and the patients¡¯ adherence to treatment for latent TB infection(AU)

Modulation of coherence and polarization using liquid crystal spatial light modulators.

We propose a method for modulation of coherence and polarization of electromagnetic fields, employing two crossed zero-twisted nematic liquid crystal spatial light modulators. In contrast to a similar technique analyzed by Shirai and Wolf [J. Opt. Soc. Am A, 21, 1907, (2004)] our method provides a wide range simultaneous modulation of coherence and polarization. The dependence of the obtained results on different definitions of electromagnetic coherence is considered.

The van Cittert-Zernike theorem for electromagnetic fields.

The van Cittert-Zernike theorem, well known for the scalar optical fields, is generalized for the case of vector electromagnetic fields. The deduced theorem shows that the degree of coherence of the electromagnetic field produced by the completely incoherent vector source increases on propagation whereas the degree of polarization remains unchanged. The possible application of the deduced theorem is illustrated by an example of optical simulation of partially coherent and partially polarized secondary source with the controlled statistical properties.