Activation of adenosine A2A receptors induces TrkB translocation and increases BDNF-mediated phospho-TrkB localization in lipid rafts : implications for neuromodulation

Copyright © 2010 the authorsBrain-derived neurotrophic factor (BDNF) signaling is critical for neuronal development and transmission. Recruitment of TrkB receptors to lipid rafts has been hown to be necessary for the activation of specific signaling pathways and modulation of neurotransmitter release by BDNF. Since TrkB receptors are known to be modulated by adenosine A2A receptor activation, we hypothesized that activation of A2A receptors could influence TrkB receptor localization among different membrane microdomains. We found that adenosine A2A receptor agonists increased the levels of TrkB receptors in the lipid raft fraction of cortical membranes and potentiated BDNF-induced augmentation of phosphorylated TrkB levels in lipid rafts. Blockade of the clathrin-mediated endocytosis with monodansylcadaverine(100µM) did not modify the effects of theA2A receptor agonists but significantly impairedBDNFeffects on TrkB recruitment to lipid rafts. The effect of A2A receptor activation in TrkB localization was mimicked by 5 µM forskolin, an adenylyl cyclase activator. Also, it was blocked by the PKA inhibitors Rp-cAMPs and PKI-(14 –22), and by the Src-family kinase inhibitor PP2. Moreover, removal of endogenous adenosine or disruption of lipid rafts reduced BDNF stimulatory effects on glutamate release from cortical synaptosomes. Lipid raft integrity was also required for the effects of BDNF on hippocampal long-term potentiation at CA1 synapses. Our data demonstrate, for the first time, a BDNF-independent recruitment of TrkB receptors to lipid rafts induced by activation of adenosine A2A receptors, with functional consequences for TrkB phosphorylation and BDNF-induced modulation of neurotransmitter release and hippocampal plasticity.Supported by Fundacão para a Ciência e a Tecnologia (SFRH/BD/21374/2005 for N.A.L., SFRH/BD/21359/2005 for V.C.S., and SFRH/BPD/11528/2002 for D.B.P.) and by the European Union [European Cooperation in Science and Technology (COST) COST B30 concerted action, Neural Regeneration and Plasticity (NEREPLAS)]

Relative peripheral refraction across 4 meridians after orthokeratology and LASIK surgery

Background: To characterize the axial and off-axis refraction across four meridians of the retina in myopic eyes before and after Orthokeratology (OK) and LASIK surgery. Methods: Sixty right eyes with a spherical equivalent (M) between − 0.75 to − 5.25 D (cylinder <− 1.00 D) underwent LASIK (n = 26) or OK (n = 34) to treat myopia. Axial and off-axis refraction were measured with an open-field autorefractometer before and after stabilized treatments. Off-axis measurements were obtained for the horizontal (35° nasal and temporal retina) and vertical (15° superior and inferior retina) meridians, and for two oblique directions (45–225° and 135–315°) up to 20° of eccentricity. The refractive profile was addressed as relative peripheral refractive error (RPRE). Results: OK and LASIK post-treatment results showed an increase of myopic relative refraction at several eccentric locations. At the four meridians evaluated, the M component of the pre-treatment RPRE values was not statistically different (p > 0.05) from the post-treatment RPRE within 30° and 20° of the central visual field after LASIK and OK, respectively. These results demonstrated that the treatment zone warrants an optimal central field of vision. Conclusions: The present study gives an overview of RPRE after refractive corneal reshaping treatments (OK and LASIK) across vertical, horizontal and two oblique meridians together. This allows a 3D representation of RPRE at the retina and shows that the myopic shift induced by both treatments is more relevant in horizontal directions.Supported in part by a grant to AQ (SFRH/BD/61768/2009), projects PTDC/ SAU-BEB/098391/2008, PTDC/SAU-BEB/098392/2008 and the Strategic Project PEST-C/FIS/UI607/2011 from the Science and Technology Foundation of Portuguese Ministry of Science and Higher Education.info:eu-repo/semantics/publishedVersio

Refractive, biometric and corneal topographic parameter changes during 12 months of orthokeratology

Background The aim of this study was to monitor refractive, topographic and biometric changes in Singaporean myopic children fitted with orthokeratology over a period of 12 months. Methods Data from 62 myopic eyes from an Asian population corrected with orthokeratology were retrospectively collected from an optometric clinic in Singapore. Anterior segment parameters were analysed with a Pentacam. Axial length was measured using the IOLMaster and refraction was assessed by subjective examination before the treatment and after one night, one week, and one, three, six and 12 months. A logistic regression model was built to evaluate the probability of slower (= 0.10 mm/year). Results Subjects had a mean age of 12.2 +/- 3.9 years (range 5-19 years), and 71 per cent were female. Baseline myopia was -3.95 +/- 1.59 D (range -1.50 and -8.75 D). Statistically significant differences were found after 12 months of treatment for refractive error, parameters of the central anterior corneal surface (curvature and elevation) and central corneal thickness. Topographic and thickness changes stabilised after one week of treatment. During 12 months of orthokeratology treatment there was a significant increase of axial length (difference = 0.11 +/- 0.18 mm, p < 0.001) while refraction remained stable. Changes in axial length of subjects above 11 years were not statistically significantly independent of the baseline myopia, and in subjects with baseline myopia greater than 4.00 D. Logistic regression showed that each additional year of age and each additional dioptre of baseline myopia decreased the probability of faster axial elongation (odds ratio [OR] = 1.23, 2.19 95% CI; OR = 1.08, 3.47 95% CI, respectively). Conclusion Corneal parameters in orthokeratology treatment were stable after one week, particularly for myopes under 4.00 D. Axial length did not change significantly in children older than 11 years of age or in subjects with myopia above 4.00 D undergoing orthokeratology treatment.- (undefined

Preliminary studies for the aplication of Thymbra capitata essential oil as potential antimicrobial agent in Bacterial Vaginosis

Bacterial vaginosis (BV) is the most common gynecological clinical condition in women in reproductive age, and has been associated with an increased risk of development of preterm labor, spontaneous abortion, and several sexually transmitted diseases such as HIV [1]. BV is not only a condition that involves excessive growth of anaerobic microorganisms, but also involves the presence of an adherent biofilm [2]. Despite its high prevalence, the aetiology of BV remains unknown, but frequently Gardnerella vaginalis is the main microorganism associated with this disorder [3], that is often the main species in biofilms presented in BV [4]. These results led to the theory that the microorganisms that form biofilms may be relevant for the aetiology of BV [5]. Traditionally, the treatment of BV involves the antibiotics metronidazole, clindamicin or tinidazole [6]. However, the recurrence rate remains high and this can be related to the biofilm-forming ability of G. vaginalis [5]. In this context, recently it was reported that natural compounds, such as Thymbra capitata essential oil, can reduce the activity of biofilms [7]. To test if T. capitata could be used in the treatment of BV, we determined the biofilm-forming ability and the effect of essential oil in seven strains of G. vaginalis isolated from women with BV. Thus, the biofilm-forming ability was assessed under anaerobic conditions for 48 hours, allowing each strain to form biofilm. These assays revealed that in fact, G. vaginalis strains produced moderate to tenacious biofilm. We then determined the sensibility of the tested bacteria to the common antibiotics used to treat BV. Not surprisingly, most of strains were resistant of metronidazole and tinidazole which are more commonly administered. However half of strains were sensitive to clindamicin. We then evaluated the antibacterial activity of essential oil upon G. vaginalis strains, determining minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC). The T. capitata essential oil exhibited a potent anti-G. vaginalis effect, which was confirmed by the low values of MIC (0.16 µL.mL-1) and MLC (0.16 - 0.31 µL.mL-1). To conclude, these results showed that T. capitata essential oil presents a strong antibacterial activity upon antibiotic resistant and biofilm forming of G. vaginalis strains, reinforcing the potential interest of this essential oil as antimicrobial agent in the treatment of BV

Evaluating SARS-CoV-2 Seroconversion Following Relieve of Confinement Measures

Funding: This work was supported by FCT grants (PTDC/MECREU/29520/2017 to HS and CHRC UIDB/4923/2020, UIPD/4923/2020). JG, MJJ, and DAS are supported by FCT through /BD/128343/2017, PTDC/EGE-OGE/32573/2017, and PD/BD/137409/2018, respectively. The anti-SARSCoV-2 ELISA assay was developed within the context of Serology4COVID consortium, in which IBET (Instituto de Biologia Experimental e Tecnológica) produced and purified the Spike protein. This initiative was supported by Calouste Gulbenkian Foundation’s Emergency Fund for COVID-19, Sociedade Francisco Manuel dos Santos and Oeiras Municipality.Seroprevalence studies are crucial both for estimating the prevalence of SARS-CoV-2 exposure and to provide a measure for the efficiency of the confinement measures. Portuguese universities were closed on March 16th 2020, when Portugal only registered 62 SARS-CoV-2 infection cases per million. We have validated a SARS-CoV-2 ELISA assay to a stabilized full-length spike protein using 216 pre-pandemic and 19 molecularly diagnosed SARS-CoV-2 positive individual's samples. At NOVA University of Lisbon, presential work was partially resumed on May 25th with staggered schedules. From June 15th to 30th, 3–4 weeks after the easing of confinement measures, we screened 1,636 collaborators of NOVA university of Lisbon for the presence of SARS-CoV-2 spike specific IgA and IgG antibodies. We found that spike-specific IgG in 50 of 1,636 participants (3.0%), none of which had anti-spike IgA antibodies. As participants self-reported as asymptomatic or paucisymptomatic, our study also provides a measurement of the prevalence of asymptomatic/paucisymptomatic SARS-CoV-2 infections. Our study suggests that essential workers have a 2-fold increase in viral exposure, when compared to non-essential workers that observed confinement. Additional serological surveys in different population subgroups will paint a broader picture of the effect of the confinement measures in the broader community.publishersversionpublishe

Emission Profiles of Carbonyl Compounds at a Brazilian Charcoal Plant

A indústria siderúrgica brasileira consome grandes quantidades de carvão vegetal. As carvoarias são responsáveis por emissões atmosféricas de compostos orgânicos voláteis tais como compostos carbonílicos (CC). Neste trabalho, foram determinados o perfil e as concentrações de CC em fase vapor durante a produção de carvão vegetal a partir de eucalipto. As amostras foram coletadas próximas aos fornos, em cartuchos de sílica revestidos com 2,4-dinitrofenilidrazina e, em seguida, extraídas e analisadas por HPLC-DAD-MS (cromatografia líquida de alta eficiência acoplada a detector de arranjo de diodo e espectrômetro de massas). Doze CC foram identificados e quantificados, entre eles acetaldeído e os pares coeluídos furfural/propanal, acroleína/propanona e 2-pentenal/pentanal. Estes três pares tiveram seus picos resolvidos por meio de espectrometria de massas para doze amostras e individualmente quantificados. Os perfis obtidos indicaram uma maior abundância do par furfural/propanal nas três fases de carbonização, seguido do acetaldeído na primeira fase e do 2-oxobutanal nas segunda e terceira fases. Furfural/propanal e acetaldeído se destacaram dentre os CC determinados nas proximidades dos fornos, com concentrações médias de 4948 e 2558 µg m -3 e concentrações máximas de 11655 e 4805 µg m -3 , respectivamente. Brazilian steel industry consumes huge amounts of charcoal. The charcoal plants are responsible for atmospheric emissions of volatile organic compounds such as carbonyl compounds (CC). In this work, the profile and the concentrations of CC in the vapor phase were determined during the charcoal production from eucalyptus. Samples were collected near kilns on silica cartridges coated with 2,4-dinitrophenylhydrazine, and then extracted and analyzed by HPLC-DAD-MS (high performance liquid chromatography coupled with diode array detector and mass spectrometry). Twelve CC were identified and quantified, amongst them acetaldehyde and the co-eluting acrolein/ propanone, furfural/propanal and 2-pentenal/pentanal pairs. These three pairs were peak resolved by mass spectra for twelve samples and thus individually quantified. The profiles obtained indicated the furfural/propanal pair as the most abundant in all three carbonization stages, followed by acetaldehyde in the first stage and 2-oxobutanal in the second and third stages. Furfural/propanal and acetaldehyde stood out among CC determined near the kilns, with average concentrations of 4948 and 2558 µg m -3 and maximum concentrations of 11655 and 4805 µg m -3 , respectively

CuMV VLPs Containing the RBM from SARS-CoV-2 Spike Protein Drive Dendritic Cell Activation and Th1 Polarization.

Dendritic cells (DCs) are the most specialized and proficient antigen-presenting cells. They bridge innate and adaptive immunity and display a powerful capacity to prime antigen-specific T cells. The interaction of DCs with the receptor-binding domain of the spike (S) protein from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a pivotal step to induce effective immunity against the S protein-based vaccination protocols, as well as the SARS-CoV-2 virus. Herein, we describe the cellular and molecular events triggered by virus-like particles (VLPs) containing the receptor-binding motif from the SARS-CoV-2 spike protein in human monocyte-derived dendritic cells, or, as controls, in the presence of the Toll-like receptors (TLR)3 and TLR7/8 agonists, comprehending the events of dendritic cell maturation and their crosstalk with T cells. The results demonstrated that VLPs boosted the expression of major histocompatibility complex molecules and co-stimulatory receptors of DCs, indicating their maturation. Furthermore, DCs' interaction with VLPs promoted the activation of the NF-kB pathway, a very important intracellular signalling pathway responsible for triggering the expression and secretion of proinflammatory cytokines. Additionally, co-culture of DCs with T cells triggered CD4+ (mainly CD4+Tbet+) and CD8+ T cell proliferation. Our results suggested that VLPs increase cellular immunity, involving DC maturation and T cell polarization towards a type 1 T cells profile. By providing deeper insight into the mechanisms of activation and regulation of the immune system by DCs, these findings will enable the design of effective vaccines against SARS-CoV-2

"I am your mother and your father!": In vitro derived gametes and the ethics of solo reproduction

In this paper, we will discuss the prospect of human reproduction achieved with gametes originating from only one person. According to statements by a minority of scientists working on the generation of gametes in vitro, it may become possible to create eggs from men’s non-reproductive cells and sperm from women’s. This would enable, at least in principle, the creation of an embryo from cells obtained from only one individual: ‘solo reproduction’. We will consider what might motivate people to reproduce in this way, and the implications that solo reproduction might have for ethics and policy. We suggest that such an innovation is unlikely to revolutionise reproduction and parenting. Indeed, in some respects it is less revolutionary than in vitro fertilisation as a whole. Furthermore, we show that solo reproduction with in vitro created gametes is not necessarily any more ethically problematic than gamete donation—and probably less so. Where appropriate, we draw parallels with the debate surrounding reproductive cloning. We note that solo reproduction may serve to perpetuate reductive geneticised accounts of reproduction, and that this may indeed be ethically questionable. However, in this it is not unique among other technologies of assisted reproduction, many of which focus on genetic transmission. It is for this reason that a ban on solo reproduction might be inconsistent with continuing to permit other kinds of reproduction that also bear the potential to strengthen attachment to a geneticised account of reproduction. Our claim is that there are at least as good reasons to pursue research towards enabling solo reproduction, and eventually to introduce solo reproduction as an option for fertility treatment, as there are to do so for other infertility related purposes