220 research outputs found

    IL4 induces IL6-producing M2 macrophages associated to inhibition of neuroinflammation in vitro and in vivo

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    Background: Myeloid cells, such as macrophages and microglia, play a crucial role in neuroinflammation and have been recently identified as a novel therapeutic target, especially for chronic forms. The general aim would be to change the phenotype of myeloid cells from pro- to anti-inflammatory, favoring their tissue-trophic and regenerative functions. Myeloid cells, however, display a number of functional phenotypes, not immediately identifiable as pro- or anti-inflammatory, and associated to ambiguous markers. Methods: We employed in vitro assays to study macrophage polarization/differentiation in the presence of classical polarizing stimuli such as IFNγ (pro-inflammatory) and IL4 (anti-inflammatory). We induced neuroinflammation in mice by immunization with a myelin antigen and treated diseased mice with intracisternal delivery of an IL4-expressing lentiviral vector. We analyzed clinical, pathological, and immunological outcomes with a focus on myeloid cells. Results: We found that IL6, usually considered a pro-inflammatory cytokine, was released in vitro by macrophages treated with the anti-inflammatory cytokine IL4. We show the existence of macrophages expressing IL6 along with classical anti-inflammatory markers such as CD206 and demonstrate that these cells are immunosuppressive in vitro. In neuroinflamed mice, we show that IL4 delivery in the central nervous system (CNS) is associated with clinical and pathological protection from disease, associated with increased IL6 expression in infiltrating macrophages. Conclusions: IL6 is known to mediate both pro- and anti-inflammatory effects, having two distinct ways to induce cell-signaling: either through the membrane bound receptor (anti-inflammatory) or through trans-signaling (pro-inflammatory). We show here that IL6-expressing macrophages are associated to protection from neuroinflammation, suggesting that IL6 anti-inflammatory properties prevail in the CNS, and calling for a general reconsideration of IL6 in macrophage polarization

    Mir-125a-3p negatively regulates oligodendrocyte precursor cells maturation and is altered in human multiple sclerosis

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    In the central nervous system, oligodendrocytes provide support to axons thanks to the production of a myelin sheath. During their maturation oligodendroglial precursors (OPCs) follow a very precise differentiation program, finely orchestrated by transcription factors, epigenetic factors and microRNAs, a class of small non-coding RNAs involved in post-transcriptional regulation. Any alterations in this program can potentially contribute to dysregulated myelination, impaired remyelination and neurodegenerative conditions, as it happens in multiple sclerosis. Recently, we identified miR-125a-3p as a new actor of oligodendroglial maturation, that could also be involved in the pathological consequences of multiple sclerosis, showing that its over-expression impairs, whereas its silencing promotes, oligodendrocyte maturation (Lecca et al., Sci Rep, 2016). To shed light on the mechanism underlying this effect, we performed a microarray analysis on OPCs after miR-125a-3p over-expression. This analysis suggested that miR-125a-3p is indeed involved in the regulation of biological processes important for OPC maturation, such as cell-cell interaction and morphological differentiation. To evaluate whether miR-125a-3p modulation may influence the progression of remyelination in vivo, we overexpressed the miR-125a-3p by lentiviral approach in a focal lysolecithin-mediated demyelinating lesion in the subcortical white matter of adult mice. Interestingly, also in this case, we found that miRNA-overexpressing OPCs persisted in an immature (i.e. PDGR\u3b1+/NG2+) state. Moreover, we found that miR-125a-3p levels are altered in both brain active lesions and cerebrospinal fluid of multiple sclerosis patients, suggesting that it could be a potential biomarker of disease. The identification of a new miRNA modulating oligodendrocyte differentiation provides new findings about the complex regulation of myelination processes and we postulate that an antago-miRNA for miR-125a-3p may help promoting oligodendrocyte maturation in diseases characterized by impaired myelin repair. Sponsored by Fondazione Italiana Sclerosi Multipla 2013/R-1 project to MPA and by Fondazione Cariplo, grant n\ub0 2014-1207 to DL

    Engineering Secretory IgA against Infectious Diseases

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    The dawn of antibody therapy was heralded by the rise of IgG therapeutics. However, other antibody classes are at our disposal—one of the most exciting is IgA and is the most abundant antibody class within humans. Unlike IgG, it is uniquely specialized for mucosal applications due to its ability to form complex Secretory IgA (SIgA) molecules. Since the mucosa is constantly exposed to potential infectious agents, SIgA is pivotal to disease prevention as an important component of the mucosal barrier. Compared to IgG, SIgA has proven superior effectiveness in mucosal surfaces, such as the airway epithelium or the harsh gut environment. Despite this, hurdles associated with low yield and challenging purification have blocked SIgA therapeutic advancement. However, as a result of new antibody engineering strategies, we are approaching the next generation of (IgA-based) antibody therapies. Strategies include fine-tuning SIgA assembly, exploring different production platforms, genetic engineering to improve purification, and glycoengineering of different components. Due to its stability in mucosal environments, SIgA therapeutics would revolutionize passive mucosal immunotherapy—an avenue still underexploited by current therapeutics. This chapter will focus on the current perspectives of SIgA engineering and explore different approaches to unlocking the full therapeutic potential of SIgAs

    Use of ultrasonography exams to determinate the parturition day by Yorkshire canine breed

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    The purpose of this study was verify the efficacy of ultrasonography to determinate the parturitionday by Yorkshire canine breed also to determinate a measures pattern embryonic vesicle diameter crown rumplenght biparietal diameter body diameter torax diameter abdomen diameter and femur length and also toestablish the linear regression formula to be used by veterinarians for this breed. The length of pregnancy fromthe date of the first mated to the first parturition signs resulted in 63,57 days. So to predict the date of parturitionwas used a multiple linear regression analyses. It was possible determinate a formula to predict the date ofparturition utilizing crown-rump length, biparietal diameter and femur length obtained a major correlation(R 0,998)., ,²Oobjetivo deste trabalho foi verificar a eficácia do método ultra-sonografico visando prever a data departo em cadelas da raça Yorkshire. Também foi objetivo determinar um padrão de mensurações de vesículagestacional, comprimento do feto, diâmetro biparietal, diâmetro do corpo, diâmetro do tórax, diâmetro deabdome e comprimento do fêmur, além de estabelecer uma fórmula de regressão linear para ser utilizada poroutros veterinários ultra-sonografistas nesta raça.Aduração da gestação a partir da data de primeira cópula atéos primeiros sinais de parto resultou numa média de 63,57 dias. Para poder predizer a data de gestação foirealizada uma análise de regressão linear multivariada. Foi possível determinar uma fórmula para prever a datade parturição em cadelas da raça Yorkshire utilizando o comprimento fetal diâmetro biparietal e comprimentodo fêmur obtendo-se significativa correlação (R =0,998)

    Metastable chaos in the ammonia ring laser

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    We report experimental studies of metastable chaos in the far-infrared ammonia ring: laser. When the laser pump power is switched from above chaos threshold to slightly below, chaotic intensity pulsations continue for a varying time afterward before decaying to either periodic or cw emission. The behavior is in good qualitative agreement with that predicted by the Lorenz equations, previously used to describe this laser. The statistical distribution of the duration of the chaotic transient is measured and shown to be in excellent agreement with the Lorenz equations in showing a modified exponential distribution. We also give a brief numerical analysis and graphical visualization of the Lorenz equations in phase space illustrating the boundary between the metastable chaotic and the stable fixed point basins of attraction. This provides an intuitive understanding of the metastable dynamics of the Lorenz equations and the experimental system

    Use of transgenic Aedes aegypti in Brazil: risk perception and assessment.

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    The OX513A strain of Aedes aegypti, which was developed by the British company Oxitec, expresses a self-limiting transgene that prevents larvae from developing to adulthood. In April 2014, the Brazilian National Technical Commission on Biosafety completed a risk assessment of OX513A and concluded that the strain did not present new biological risks to humans or the environment and could be released in Brazil. At that point, Brazil became the first country to approve the unconstrained release of a genetically modified mosquito. During the assessment, the commission produced a comprehensive list of ? and systematically analysed ? the perceived hazards. Such hazards included the potential survival to adulthood of immature stages carrying the transgene ? should the transgene fail to be expressed or be turned off by exposure to sufficient environmental tetracycline. Other perceived hazards included the potential allergenicity and/or toxicity of the proteins expressed by the gene, the potential for gene flow or increased transmission of human pathogens and the occupation of vacant breeding sites by other vector species. The Zika epidemic both elevated the perceived importance of Ae. aegypti as a vector ? among policy-makers and regulators as well as the general public ? and increased concerns over the release of males of the OX513A strain. We have therefore reassessed the potential hazards. We found that release of the transgenic mosquitoes would still be both safe and of great potential value in the control of diseases spread by Ae. aegypti, such as the chikungunya, dengue and Zika virus disease

    Policy masquerading as science: an examination of non-state actor involvement in European risk assessment policy for genetically modified animals

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    In 2013, at the request of the European Commission, the European Food Safety Authority (EFSA) announced a new risk assessment policy: Guidance on the environmental risks of genetically modified (GM) animals (‘Guidance’). This policy specifies the issues to be addressed in future risk assessments for GM animals. EFSA is the European Commission's scientific arm, responsible for food-related risk assessment. EFSA relies heavily on independent experts and consults non-state actors. Employing expert interviews and documentary analysis, the article explores non-state actor involvement in a traditionally expert domain through a case study. Analysis of EFSA's consultation demonstrates the inability of non-state actors to influence policy. The article argues that despite international legal obligations to develop risk assessment policy, the European Commission failed to recognize the Guidance as policy. When policy masquerades as science, unjustified restrictions are placed on non-state actor involvement and value judgements are cloaked from public scrutiny

    Expression of AMPA and NMDA receptor subunits in the cervical spinal cord of wobbler mice

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    BACKGROUND: The localisation of AMPA and NMDA receptor subunits was studied in a model of degeneration of cervical spinal motoneurons, the wobbler mouse. Cervical regions from early or late symptomatic wobbler mice (4 or 12 weeks of age) were compared to lumbar tracts (unaffected) and to those of healthy mice. RESULTS: No differences were found in the distribution of AMPA and NMDA receptor subunits at both ages. Western blots analysis showed a trend of reduction in AMPA and NMDA receptor subunits, mainly GluR1 and NR2A, exclusively in the cervical region of late symptomatic mice in the triton-insoluble post-synaptic fraction but not whole homogenates. Colocalisation experiments evidenced the expression of GluR1 and NR2A receptors in activated astrocytes from the cervical spinal cord of wobbler mice, GluR2 did not colocalise with GFAP positive cells. No differences were found in the expression of AMPA and NMDA receptor subunits in the lumbar tract of wobbler mice, where neither motoneuron loss nor reactive gliosis occurs. CONCLUSION: In late symptomatic wobbler mice altered levels of GluR1 and NR2A receptor subunits may be a consequence of motoneuron loss rather than an early feature of motoneuron vulnerability
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