Endothelial adhesive platforms and docking structures: molecular composition, biophysical properties, dynamics and involvement in leukocyte firm adhesion

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 18-10-200

Evaluating the potential of natural polymers for water-dispersible curcumin-based solid dispersion colourant systems for food applications

Solid dispersion (SD) technology, a strategy through which a hydrophobic compound is molecularly dispersed into a hydrophilic carrier, is raising interest in food applications to surpass natural colourants’ low water solubility. Motivated by the importance of using natural solutions, five natural polymers (k-carrageenan (KC), maltodextrin (MD), Arabic gum (AG), potato starch (PS), and pectin (PC) were evaluated against the synthetic benchmark polyvinylpyrrolidone (PVP)). Targeting a stable yellow hue, pH 6 was used, and the effect of salt addition on crystallinity was evaluated. Comparatively with PVP, used as a synthetic polymer reference, SDs based on MD, AG, and PC presented a deeper orange shade. Similar size distributions were achieved for the produced samples except for PS-based SDs, which showed higher sizes in volume. For all systems, polymer-curcumin hydrogen bonding was perceptible and reflected in the curcumin crystallinity modification/reduction, particularly if produced under natural pH conditions. The water solubility was significantly improved compared to free curcumin, from 1 μg/mL to 25–37 μg/mL (pH 6, PVP - 24.54 μg/mL) and 18–86 μg/mL (without pH control, PVP - 28.34 μg/mL), highlighting the favourable effect of natural polymers.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2021), LSRE-LCM (UIDB/50020/2020 and UIDP/00690/2020) and ALiCE (LA/P/0045/2020). FCT for the Research grant SFRH/BD/147326/2019 of Stephany C. de Rezende and national funding by FCT, PI, through the institutional scientific employment program contract for Arantzazu Santamaria-Echart. In addition, the technical support provided by I3Bs- Research Institute on Biomaterials, Biodegradables and Biomimetics of the University of Minho is also acknowledgedinfo:eu-repo/semantics/publishedVersio

In-service teacher training in Portugal: objectives, organization and impact on teacher's career

This paper presents a short overview of teacher´s training as considered by the Portuguese legislation: (i) initial teacher education (ITE), (ii) specialized training and (iii) in-service teacher training. A particular emphasis will be given to in-service teacher training. Nowadays, ITE corresponds to level 7 of the European Qualifications Framework (master degree). It is a career-long professional development, where research-based and in context practice are important features. Specialized training is intended to provide qualification in complementary educational functions, such as special education, school administration and inspection activities, socio-cultural animation and basic education for adults. In-service training or continuous training allows teachers to complement, deepen and update their knowledge and professional competences. Its accreditation, in what concerns involved institutions, training actions and evaluation process is centralized in the “Conselho Científico-Pedagógico da Formação Contínua” (Scientific and Pedagogical Council of in-service training) and has a direct impact in teacher’s careers, being one of the factors considered to access mobility and progression

An overview of teacher training in Portugal

This paper presents an overview of teacher´s training in Portugal concerning initial teacher training (ITE), specialized training and in-service teacher training, as considered by the Portuguese legislation. A special emphasis was given to training in information and communication technologies (ICT) and to teaching of experimental sciences for primary school. Moreover, chemistry teacher’s training was contextualized in this scenario. Presently ITE corresponds to level 7 of the European Qualifications Framework (master degree). It is a career-long professional development, where research-based and in context practice are important features. Nevertheless the implicit valorisation of the teaching career arising from Bologna process implementation, a master degree is needed for all teaching levels; a lack of motivation to pursue teaching careers is generally noticed in Portugal as a consequence of the actual context of a surplus and unemployment among the new teachers. Following ITE, in-service training allows teachers to complement, deepen and update their knowledge and professional competences. This is an important measure for in-service long date teachers’ and particularly relevant for the ones that, following teacher career reorganization, had to readapt to new curricula and even new teaching subjects

E-Learning from nature: picking from nature the inspiration to teach and learn science

This work aims to present the work done so far by the Polytechnic Institute of Bragança (IPB) within the project E-learning from Nature. The project includes, at national level, a network of secondary schools from the district of Bragança and aims to promote a proactive students’ approach to scientific subjects learning and propose innovative teaching methodologies to science teachers. Five geographical areas of natural interest have been selected: Azibo Reservoir Protected Landscape, Douro International Natural Park, Montesinho Natural Park, Landscapes of Serra da Nogueira and the Cork oak forests of Jerusalém do Romeu. Among the scientific topics to be illustrated by examples found in nature, Mathematics, Biology, Geology, Physics, Chemistry and/or Geography are in focus. Apart from the work to be done at national level, a fruitful cooperation is expected from the exchange of experiences among the international partners (Italy, Belgium, Ireland, Greece, Lithuania, Portugal and Romania).Project funded by Erasmus + Programme (Project Number 2015-1-IT02-KA201-015133).info:eu-repo/semantics/publishedVersio

Señalización derivada de la interacción leucocito-endotelio durante la inflamación

Leukocyte trafficking throughout the vasculature is a crucial step for the development of innate and adaptive immunity (1). The coordinate function of adhesion receptors, cytoskeleton and signaling molecules in both cellular types is fundamental during leukocyte extravasation. Hence, the correct integration of “outside-in” and “inside-out” signals in leukocytes and endothelium during each stage of the process is critical to allow the completion of the so-called “multi-step paradigm” (leukocyte tethering and rolling involving selectins and their ligands, followed by leukocyte firm adhesion and crawling mediated by integrins and their endothelial counter-receptors and the subsequent diapedesis also mediated by junctional proteins) (2, 3). This review focuses on the signaling pathways triggered during the extravasation that allow leukocytes to efficiently migrate towards the inflammatory foci to exert their effector functions.Key Words: Inflammation, Leukocyte adhesion, Transendothelial migration, Adhesion receptor signaling.El tráfico leucocitario a través de la vasculatura es un paso crucial para el desarrollo de la inmunidad innata y adaptativa. El funcionamiento coordinado de los receptores de adhesión, el citoesqueleto y las moléculas señalizadoras tanto en el leucocito como en el endotelio es fundamental durante el proceso de extravasación. Así, la correcta integración de las señales del exterior hacia el interior y del interior hacia el exterior en ambos tipos celulares durante cada etapa del proceso es crítica para la consecución del llamado “paradigma multi-secuencial” (el rodamiento de los leucocitos en el que están implicadas las selectinas y sus ligandos, seguido de la adhesión firme mediada por las integrinas leucocitarias y sus contra-receptores endoteliales, así como el subsiguiente paso de diapedesis en el que también están implicadas moléculas típicas de uniones intercelulares). Esta revisión se centra en las vías de señalización que se desencadenan durante la extravasación que permiten a los leucocitos migrar de manera eficiente hacia los focos inflamatorios donde ejercen sus funciones efectoras. Palabras clave: Inflamación, Adhesión leucocitaria, Migración transendotelial, Señalización mediada por receptores de adhesión

Role of Tetraspanins CD9 and CD151 in Primary Melanocyte Motility

Tetraspanins CD9 and CD151 have been implicated in cellular motility and intercellular adhesion in several cellular types. Here, we have studied the subcellular localization and the functional role of these molecules in primary melanocytes. We found that endogenous tetraspanins preferentially clustered in areas of melanocyte homotypic intercellular contacts and at the tips of dendrites. These observations were further confirmed using time-lapse fluorescence confocal microscopy of melanocytes transfected with CD9– and CD151–GFP (green fluorescent protein) constructs, suggesting an involvement of these proteins in cellular contacts and migration. Cell adhesion and migration assays performed using blocking monoclonal antibodies against CD9 and CD151 showed no significant effect on cell–extracellular matrix adhesion, whereas the migration of melanocytes was significantly enhanced. The regulation of the migratory capacity of melanocytes by CD9 and CD151 was further confirmed knocking down the endogenous expression of these tetraspanins with small interference RNA oligonucleotides. Therefore, tetraspanin molecules are localized at motile structures in primary human melanocytes regulating the migratory capacity of these cells

Caveolin-1 deficiency induces a MEK-ERK1/2-Snail-1-dependent epithelial-mesenchymal transition and fibrosis during peritoneal dialysis

Peritoneal dialysis (PD) is a form of renal replacement therapy whose repeated use can alter dialytic function through induction of epithelial-mesenchymal transition (EMT) and fibrosis, eventually leading to PD discontinuation. The peritoneum from Cav1-/- mice showed increased EMT, thickness and fibrosis. Exposure of Cav1-/- mice to PD fluids further increased peritoneal membrane thickness, altered permeability and increased the number of FSP-1/cytokeratin-positive cells invading the sub-mesothelial stroma. High-throughput quantitative proteomics revealed increased abundance of collagens, FN and laminin, as well as proteins related to TGF- activity in matrices derived from Cav1-/- cells. Lack of Cav1 was associated with hyperactivation of a MEK-ERK1/2-Snail-1 pathway that regulated the Smad2-3/Smad1-5-8 balance. Pharmacological blockade of MEK rescued E-cadherin and ZO-1 inter-cellular junction localization, reduced fibrosis and restored peritoneal function in Cav1-/- mice. Moreover, treatment of human PD-patient-derived MCs with drugs increasing Cav1 levels, as well as ectopic Cav1 expression, induced reacquisition of epithelial features. This study demonstrates a pivotal role of Cav1 in the balance of epithelial versus mesenchymal state and suggests targets for the prevention of fibrosis during PD

Association between Breast Milk Mineral Content and Maternal Adherence to Healthy Dietary Patterns in Spain: A Transversal Study

The composition of breast milk is influenced by many factors, some of which dependent on the mother and others on the child. Changes in lactation and other factors depending on the mother’s physiology and anthropometric characteristics, as well as her nutritional status and diet, are of key importance. Breast milk minerals have been extensively studied with highly uneven results. In this work, a comparison will made with data across the world. To understand the factors that might explain the disparity, several minerals (Na, K, Ca, P, Mg, Fe, Se and I) have been analyzed using ICP-MS in a set of human milk samples (n = 75). The samples had an identical geographical origin (Galicia, in northwestern Spain) but different lactation circumstances, including maternal anthropometric data, lactating time, newborn sex and maternal adherence to healthy dietary patterns (Mediterranean Diet, MD, or Atlantic Diet, AD). The required concentrations of essential elements reported in the literature are similar to those found in these Spanish women. A univariate approach revealed that factors such as lactating time, body mass index (BMI) and newborn sex have a significant influence in breastmilk mineral content. According to multivariate linear regression analysis, minerals in milk are particularly associated with lactating time, but also with newborn sex, maternal BMI, age and diet pattern in some cases. More precisely, these results suggest that the iron and selenium concentrations in the milk of Galician donors may be positively influenced by maternal adherence to AD and MD, respectivelyS

Specific Targeting of Human Inflamed Endothelium and In Situ Vascular Tissue Transfection by the Use of Ultrasound Contrast Agents

ObjectivesWe used human umbilical cord segments as an ex vivo model to investigate the possible clinical diagnostic and therapeutic applications of microbubbles (MBs).BackgroundMicrobubbles are commonly used in clinical practice as ultrasound contrast agents. Several studies have addressed the in vivo applications of MBs for specific targeting of vascular dysfunction or sonoporation in animal models, but to date no human tissue model has been established.MethodsPrimary venular endothelial cell monolayers were targeted with MBs conjugated to an antibody against a highly expressed endothelial marker (tetraspanin CD9), and binding was assessed under increasing flow rates (0.5 to 5 dynes/cm2). Furthermore, CD9-coupled MB endothelial targeting was measured under flow conditions by contrast-enhanced ultrasound analysis in an ex vivo human macrovascular model (umbilical cord vein), and the same tissue model was used for the detection of inflamed vasculature with anti-intercellular adhesion molecule (ICAM)-1–coated MBs. Finally, plasmids encoding fluorescent proteins were sonoporated into umbilical cord vessels.ResultsSpecific endothelial targeting in the in vitro and ex vivo models described previously was achieved by the use of MBs covered with an anti-CD9. Furthermore, we managed to induce inflammation in umbilical cord veins and detect it with real-time echography imaging using anti–ICAM-1–coupled MBs. Moreover, expression and correct localization of green fluorescent protein and green fluorescent protein-tagged ICAM-1 were assessed in this human ex vivo model without causing vascular damage.ConclusionsIn the absence of clinical trials to test the benefits and possible applications of ultrasound contrast agents for molecular imaging and therapy, we have developed a novel ex vivo human model using umbilical cords that is valid for the detection of inflammation and for exogenous expression of proteins by sonoporation