Estudi de tècniques immunològiques a través de “Podcasts” elaborats pels estudiants

Projecte: 2013-PID-UB/10La realització de “podcasts” o sessions formatives audiovisuals per part d’estudiants de postgrau permet treballar diferents competències transversals, entre elles habilitats comunicatives útils per al desenvolupament del seu futur exercici professional (2013-PID-UB/10). Els estudiants han elaborat un guió que posteriorment han convertit en “podcast”. Cada estudiant ha valorat els “podcasts” dels companys i el seu propi mitjançant una rúbrica dissenyada amb aquest objectiu.Programa de Millora i innovació docent,PMID: 2013-PID-UB/1

Monocarboxylate transporter 1 mediates DL-2-hydroxy-(4-methylthio)butanoic acid transport across the apical membrane of Caco-2 cell monolayers.

The methionine hydroxy analogue DL-2-hydroxy-(4-methylthio)butanoic acid (DL-HMB) is a supplementary source of methionine commonlyadded to commercial animal diets to satisfy the total sulfur amino acid requirement. In this study, we characterized DL-HMB transport acrossthe apical membrane of Caco-2 cells to identify the transport mechanism involved in the intestinal absorption of this methionine source. DLHMBtransport induced a significant decrease in intracellular pH (pHi) and was inhibited in the presence of the protonophore carbonyl cyanide 4-(trifluoromethoxy)-phenylhydrazone. Moreover, both Na1 removal and 5-(N-ethyl-N-isopropyl)amiloride, an inhibitor of apical Na1/H1 exchanger(NHE3), significantly reduced substrate uptake and pHi recovery, suggesting cooperation between H1-dependent DL-HMB transport and NHE3activity. cis-Inhibition experiments with L-Ala, b-Ala, D-Pro, betaine, or glycyl-sarcosine excluded the participation of systems proton amino acidtransporter 1 and peptide transporter 1. In contrast, a-cyano-4-hydroxycinnamate, phloretin, L-lactate, b-hydroxybutyrate, butyrate, andpyruvate, inhibitors and substrates of monocarboxylate transporter 1 (MCT1), significantly reduced DL-HMB uptake. Dixon plot analysis of Llactatetransport in the presence of DL-HMB revealed a competitive interaction (inhibition constant, 17.5 6 0.11 mmol/L), confirming theparticipation of system MCT1. The kinetics of DL-HMB uptake was described by a model involving passive diffusion and a single low-affinity,high-capacity transport mechanism (KD, 1.9 nL/mg protein; Km, 13.16 0.04 mmol/L; and Vmax, 43.6 6 0.14 pmol/mg protein) compatible withMCT1 kinetic characteristics. In conclusion, the methionine hydroxy analogue is transported in Caco-2 cell apical membrane by a transportmechanism with functional characteristics similar to those of MCT1.</p

Study of Melatonin as Preventive Agent of Gastrointestinal Damage Induced by Sodium Diclofenac

: Safety profile of nonsteroidal anti‐inflammatory drugs (NSAIDs) has been widely studied and both therapeutic and side effects at the gastric and cardiovascular level have been generally associated with the inhibitory effect of isoform 1 (COX‐1) and 2 (COX‐2) cyclooxygenase enzymes. Now there are evidences of the involvement of multiple cellular pathways in the NSAIDs‐mediated‐gastrointestinal (GI) damage related to enterocyte redox state. In a previous review we summarized the key role of melatonin (MLT), as an antioxidant, in the inhibition of inflammation pathways mediated by oxidative stress in several diseases, which makes us wonder if MLT could minimize GI NSAIDs side effects. So, the aim of this work is to study the effect of MLT as preventive agent of GI injury caused by NSAIDs. With this objective sodium diclofenac (SD) was administered alone and together with MLT in two experimental models, ex vivo studies in pig intestine, using Franz cells, and in vivo studies in mice where stomach and intestine were studied. The histological evaluation of pig intestine samples showed that SD induced the villi alteration, which was prevented by MLT. In vivo experiments showed that SD altered the mice stomach mucosa and induced tissue damage that was prevented by MLT. The evaluation by quantitative reverse transcription PCR (RT‐qPCR) of two biochemical markers, COX‐2 and iNOS, showed an increase of both molecules in less injured tissues, suggesting that MLT promotes tissue healing by improving redox state and by increasing iNOS/NO that under non‐oxidative condition is responsible for the maintenance of GI‐epithelium integrity, increasing blood flow and promoting angiogenesis and that in presence of MLT, COX‐2 may be responsible for wound healing in enterocyte. Therefore, we found that MLT may be a preventive agent of GI damages induced by NSAIDs. Keywords: melatonin; NSAIDs; gastric injuries; antioxidan

PGE2 promotes Ca2+-mediated epithelial barrier disruption through EP1 and EP4 receptors in Caco-2 cell monolayers

We recently demonstrated that PGE(2) induces the disruption of the intestinal epithelial barrier function. In the present study, our objectives were to study the role of PGE(2) receptors (EP(1)-EP(4)) and the signaling pathways involved in this event. Paracellular permeability (PP) was assessed in differentiated Caco-2 cell cultures from d-mannitol fluxes and transepithelial electrical resistance (TER) in the presence of different PGE(2) receptor agonists (carbacyclin, sulprostone, butaprost, ONO-AE1-259, ONO-AE-248, GR63799, and ONO-AE1-329) and antagonists (ONO-8711, SC-19220, AH-6809, ONO-AE3-240, ONO-AE3-208, and AH-23848). The results indicate that EP(1) and EP(4) but not EP(2) and EP(3) might be involved in PP regulation. These effects were mediated through PLC-inositol trisphosphate (IP(3))-Ca(2+) and cAMP-PKA signaling pathways, respectively. We also observed an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) strengthened by cAMP formation indicating a cross talk interaction of these two pathways. Moreover, the participation of a conventional PKC isoform was shown. The results also indicate that the increase in PP may be correlated with the redistribution of occludin, zona occludens 1 (ZO-1), and the perijunctional actin ring together with an increase in myosin light chain kinase activity. Although the disruption of epithelial barrier function observed in inflammatory bowel disease (IBD) patients has been traditionally attributed to cytokines, the present study focused on the role of PGE(2) in PP regulation, as mucosal levels of this eicosanoid are also increased in these inflammatory processes.</p

Implicación del estudiante de postgrado en el proceso de evaluación de su aprendizaje

Podeu consultar la Vuitena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/66524La asignatura "Fonaments d’Immunología" del Máster Oficial Interuniversitario URV-UB en Nutrición y Metabolismo es cursada anualmente por unos 20-30 estudiantes. El hecho de tratarse de un grupo reducido permite implementar metodologías que ayuden a promover un aprendizaje más significativo y, entre ellas, la implicación del estudiante en el proceso de evaluación de los conocimientos adquiridos. El objetivo de la presente innovación consistió precisamente en implicar al estudiante en el diseño de una de las propias pruebas de evaluación así como de valorar los trabajos de sus compañeros y el suyo propio. Concretamente, los estudiantes del curso 2014/15 tenían que escoger una técnica inmunológica, lo que les permitía aplicar los conocimientos impartidos en el curso, y desarrollarla en parejas en forma de presentación. Además se les solicitó que elaboraran preguntas test sobre el contenido trabajado. La puntuación de la prueba de evaluación consistió en la valoración de la presentación y en una prueba escrita tipo test sobre todas las exposiciones realizadas. Para calificar las presentaciones, cada estudiante valoró las de los compañeros (corrección por iguales) y la suya propia (autoevaluación) mediante una rúbrica de tres categorías, idéntica a la que utilizó el profesor. Por otra parte, el equipo docente seleccionó varias preguntas de los estudiantes. Las mejores fueron utilizadas para la prueba tipo test, mientras que las de menor claridad, fueron comentadas en clase para aprender de sus errores o problemas de ambigüedad. Se obtuvieron indicadores cualitativos sobre la estrategia docente mediante una encuesta de opinión. Éstos indican que los estudiantes han adquirido consciencia de la importancia de las rúbricas para una evaluación objetiva y de la dificultad en la elaboración de preguntas test, así como del aprendizaje adquirido durante su preparación. Por otra parte, los estudiantes se han mostrado muy satisfechos con la utilidad e interés suscitado, así como de la experiencia globalmente (puntuaciones superiores a 8,5 sobre 10 en todos los casos)

Flavonoids affect host-microbiota crosstalk through TLR modulation

Interaction between host cells and microbes is known as crosstalk. Among other mechanisms, this takes place when certain molecules of the micro-organisms are recognized by the toll-like receptors (TLRs) in the body cells, mainly in the intestinal epithelial cells and in the immune cells. TLRs belong to the pattern-recognition receptors and represent the first line of defense against pathogens, playing a pivotal role in both innate and adaptive immunity. Dysregulation in the activity of such receptors can lead to the development of chronic and severe inflammation as well as immunological disorders. Among components present in the diet, flavonoids have been suggested as antioxidant dietary factors able to modulate TLR-mediated signaling pathways. This review focuses on the molecular targets involved in the modulatory action of flavonoids on TLR-mediated signaling pathways, providing an overview of the mechanisms involved in such action. Particular flavonoids have been able to modify the composition of the microbiota, to modulate TLR gene and protein expression, and to regulate the downstream signaling molecules involved in the TLR pathway. These synergistic mechanisms suggest the role of some flavonoids in the preventive effect on certain chronic diseases

Dietary Consumption of Polyphenols in University Students Relationship with Their Health-Related Habits

Polyphenols are compounds derived from plants found in foods with potential health benefits due to their antioxidant properties. The aim of this study was to establish the consumption of polyphenols in university students and the relationship between the amount of polyphenols consumed and their health-related habits. For this, 270 university students answered a validated food consumption frequency questionnaire (FFQ), a physical activity questionnaire (IPAQ), and a health and lifestyle questionnaire. From the FFQ, the daily consumption of classes and subclasses of polyphenols was calculated. Then, the population was classified in terciles according to the polyphenol consumption, and the physical activity, smoking habits, and the prevalence of allergy and obesity in each tercile was established. The consumption of polyphenols was about 1.5 g/day, being flavonoids and phenolic acids the most consumed. The main sources of polyphenol consumption were cocoa, coffee, and to a lesser extent, fruits. There were no significant differences in consumption according to sex, BMI, health status, or physical activity. The smoking habit was related to a high consumption of polyphenols, mainly those that came from coffee and cocoa. Students who smoke had a higher consumption of polyphenols with respect to nonsmokers, especially those derived from coffee

Relationship between Cocoa Intake and Healthy Status: A Pilot Study in University Students

Due to its polyphenol content, cocoa's potential health effects are attracting much attention, showing, among other things, cardioprotective, anti-inflammatory, anti-obesity, and neuroprotective actions. However, there is very limited information regarding the effect of cocoa on human immunity. This study aimed to establish the relationship between cocoa consumption and health status, focusing on physical activity habits and allergy prevalence in young people. For this, a sample of 270 university students was recruited to complete a food frequency questionnaire, the International Physical Activity Questionnaire (IPAQ), and a lifestyle and health status questionnaire. The results were analysed by classifying the participants into tertiles defined according to their cocoa consumption: low (LC), moderate (MC), and high (HC) consumers. The consumption of cocoa inversely correlated with physical activity and the MC group had significantly less chronic disease frequency than the LC group. The percentage of allergic people in the MC and HC groups was lower than that in the LC group and, moreover, the cocoa intake, especially moderate consumption, was also associated with a lower presence of allergic symptoms. Thus, from these results a positive effect of cocoa intake on allergy can be suggested in the young population. View Full-Text Keywords: allergy; cacao; chocolate; food frequency questionnaire; International Physical Activity Questionnaire; young peopl

Effect of pH on L- and D-methionine uptake across the apical membrane of Caco-2 cells

The transport systems involved in intestinal methionine (Met) absorption are described as Na(+)-dependent and Na(+)-independent mechanisms. However, since recent studies have suggested the importance of the H(+) gradient as a driving force for intestinal nutrient absorption, the aim of the present work was to test whether Met transport across the apical membrane of Caco-2 cells is affected by extracellular pH. The results show that l- and d-Met uptake was increased by lowering extracellular pH from 7.4 to 5.5, in both the presence and absence of Na(+). Cis-inhibition experiments revealed that inhibition of l-Met transport by 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH) or l-lysine (l-Lys) was higher at a pH of 5.5. Moreover, the BCH-insensitive component was not affected by pH, whereas the l-Lys-insensitive component was increased by lowering extracellular pH, thus suggesting the participation of system L. The contribution of another mechanism, sensitive to both BCH and l-Lys, was also considered. The inhibition obtained with taurine (Tau) was also higher at a pH of 5.5, thus suggesting the involvement of system B(0,+) on pH-stimulated component. As for d-Met uptake, the results showed higher inhibition with l-Lys and Tau at a pH of 5.5 and no effect on the l-Lys- or Tau-insensitive component. In conclusion, Met transport across the apical membrane of Caco-2 cells is increased by low extracellular pH as the result of the stimulation of two transport systems functionally identified with systems L and B(0,+) for l-Met and with system B(0,+) for d-Met

Ludificació en Immunonutrició: tres estratègies per jugar amb els nutrients i el sistema immunitari

Amb la finalitat d'obtenir un aprenentatge més significatiu dels continguts de l'assignatura d'Immunonutrició, s'han portat a terme 3 activitats diferents per tal de ludificar el desenvolupament de les classes. Segons l'opinió dels estudiants les tres actuacions han estat altament satisfactòries. A més, el fet de poder obtenir el reforç addicional en la qualificació final de l'assignatura ha demostrat ser un motor per a la implicació dels estudiants en la dinàmica de classe