Probióticos, Prebióticos y Salud: Evidencia Científica

24 páginas.-- Resúmenes de las ponencias presentadas al II Workshop Científico: Probióticos, prebióticos y salud: evidencia científica, celebrado en Madrid del 16 al 17 de Diciembre de 2010.-- et al.Peer reviewe

Rga6 is a fission yeast Rho GAP involved in Cdc42 regulation of polarized growth

Active Cdc42 is essential for the establishment of polarized growth. This GTPase is negatively regulated by the GTPase-activating proteins (GAPs), which are important for the spatial specificity of Cdc42 function. Rga4 is the only GAP described as negative regulator of fission yeast Cdc42. We report here that Rga6, another fission yeast Cdc42 GAP, shares some functions with Rga4. Cells lacking Rga6 are viable but slightly shorter and broader than wild type, and cells lacking Rga6 and Rga4 simultaneously are rounded. In these cells, active Cdc42 is observed all around the membrane. These additive effects indicate that both GAPs collaborate in the spatial regulation of active Cdc42. Rga6 localizes to the plasma membrane, forming clusters different from those formed by Rga4. A polybasic region at the Rga6 C-terminus is responsible for its membrane localization. Rga6-GFP fluorescence decreases considerably at the growing tips, and this decrease is dependent on the actin cables. Of note, in the absence of Rga6, the amplitude of active Cdc42 oscillations at the tips decreases, and less GTP-Cdc42 accumulates at the new end of the cells. We propose that Rga6 collaborates with Rga4 to spatially restrict active Cdc42 at the cell tips and maintain cell dimensions.This work was supported by Grants BFU2013-43439-P and BIO2015-69958-P from the Ministry of Economy and Competitiveness, Spain, and Grant CSI037U14 from Junta de Castilla y León, Spain.Peer Reviewe

Rga2 IS a Rho2 GAP that regulates morphogenesis and cell integrity in Schizosaccharomyces pombe

15 pages, 8 figures.-- PMID: 18793338 [PubMed].-- Supporting information (Table S1: List of strains used in the study) available at: http://www3.interscience.wiley.com/journal/121408738/suppinfoSchizosaccharomyces pombe Rho2 GTPase regulates alpha-D-glucan synthesis and acts upstream of Pck2 to activate the MAP kinase pathway for cell integrity. However, little is known about its regulation. Here we describe Rga2 as a Rho2 GTPase-activating protein (GAP) that regulates cell morphology. rga2+ gene is not essential for growth but its deletion causes longer and thinner cells whereas rga2+ overexpression causes shorter and broader cells. rga2+ overexpression also causes abnormal accumulation of Calcofluor-stained material and cell lysis, suggesting that it also participates in cell wall integrity. Rga2 localizes to growth tips and septum region. The N-terminal region of the protein is required for its correct localization whereas the PH domain is necessary exclusively for Rga2 localization to the division area. Also, Rga2 localization depends on polarity markers and on actin polymerization. Rga2 interacts with Rho2 and possesses in vitro and in vivo GAP activity for this GTPase. Accordingly, rga2Delta cells contain more alpha-D-glucan and therefore partially suppress the thermosensitivity of mok1-664 cells, which have a defective alpha-D-glucan synthase. Additionally, genetic interactions and biochemical analysis suggest that Rga2 regulates Rho2-Pck2 interaction and might participate in the regulation of the MAPK cell integrity pathway.This work was supported by grants BIO2004-0834, BFU2005-01401 and BFU2007-60675 from the Comisión Interministerial de Ciencia y Tecnología, Spain and by grant SA078A07 from Junta de Castilla y León, Spain.Peer reviewe

Commercial Conjugated Linoleic Acid (CLA) Fortified Dairy Products

Conjugated linoleic acid (CLA) is a mixture of positional and geometric conjugated isomers of the essential linoleic fatty acid (LA, C18:2 cis 9, cis 12) characterized by the presence of double bonds from 6 to 14 position (6–8; 7–9; 8–10; 9–11; 10–12; 11–13; 12–14) and four conformations (cis, trans; trans, cis; trans, trans, and cis, cis) yielding 28 possible isomers [1]. The CLA is mainly found in food products from ruminants such as dairy products (0.34–1.07 g/100 g fat) [2] and beef (0.12–0.68 g/100 g fat) [3], because it is produced as an intermediate in the biohydrogenation pathway by ruminal bacteria (Fig. 14.1). The most abundant isomers (Table 14.1) are rumenic acid (RA; C18:2 cis 9, trans 11) accounting 75–90 % of total CLA in milk fat and C18:2 trans 7, cis 9 with 3–16 % [4]. Many research works had investigated the biological effects of RA reporting anticarcinogenic [10], antiaterogenic [11], antioxidative [12], and stimulation of the immune system [13]. Reduction of body fat [14] (antiobesity activity) has been associated with the C18:2 trans 10, cis 12 isomer mainly present in CLA synthetic oils. In the current market there are available rich CLA oils with a concentration of 80 g CLA/100 g oil with a 1:1 mixture of the two major isomers C18:2 cis 9, trans 11 and C18:2 trans 10, cis 12 and other minor isomers consisting of all cis/trans isomers of C18:2 9,11; 10,12 and 11,13 [15]. Various methods are available to produce synthetic CLA oil but alkaline isomerization of linoleic acid is the most common method [16] (Fig. 14.2).Peer reviewe

Complete genome sequence of Bifidobacterium breve CECT 7263, a strain isolated from human milk

Bifidobacterium breve is an actinobacterium frequently isolated from colonic microbiota of breastfeeding babies. Here, we report the complete and annotated genome sequence of a B. breve strain isolated from human milk, B. breve CECT 7263. The genome sequence will provide new insights into the biology of this potential probiotic organism and will allow the characterization of genes related to beneficial properties. © 2012, American Society for Microbiology.This study was partly supported by the FUN-C-FOOD (Consolider-Ingenio 2010) and AGL2010-15420 projects from the Ministerio de Economía y Competitividad (Spain) and by a research contract funded by Lactalis Puleva.Peer Reviewe

Lípidos bioactivos en productos lácteos

Trabajo presentado a la I Jornada CYTED-IBEROFUN sobre Alimentación y Salud, celebrada en México en 2010.En la actualidad, las recomendaciones dietéticas reconocen que la leche y los productos lácteos son una excelente fuente de nutrientes esenciales (ej: calcio, potasio, magnesio, zinc, riboflavina, vitamina A, folato, vitamina D y proteínas de elevada calidad nutricional), así como un vehículo ideal de componentes bioactivos que pueden aportar beneficios para la salud humana.Proyecto CYTED IBEROFUN ref: 110AC0386 “Incorporación de nuevos ingredientes funcionales a alimentos como contribución a la promoción de la salud y/o a la prevención de enfermedades de la población Iberoamericana.Peer Reviewe

Lípidos bioactivos en productos lácteos

Financiamiento por el proyecto Fondo de Fomento al Desarrollo Científico y Tecnológico Regional (FONDEF), Región de Los Ríos “Desarrollo de una línea base para la potencial generación de productos lácteos diferenciados y protocolos de producción de leche y derivados de alto valor nutricional".Peer reviewe

Desarrollo de una línea base para la potencial generación de productos lácteos diferenciados y potocolos de producción de leche y derivados de alto valor nutricional

Boletín completo del Instituto de Investigaciones Agropecuarias (Chile).-- et al.En el contexto de los desafíos de la industria alimentaria del siglo 21, se plantea la necesidad de incrementar la producción en un 100% de alimentos para la población mundial del año 2050. Sin embargo, éstos alimentos además deben apuntar a una mejor nutrición con bajo impacto ambiental, temáticas que se fusionan en el concepto de nutrición sustentable. Para el sector lácteo este desafío implica un aumento en la producción de 900 millones de toneladas de leche fresca equivalentes a nivel mundial según cálculos derivados de informes de la FAO. Junto al aumento de producción, el desafío para el sector lácteo global incluye además la entrega de productos lácteos nutritivos, saludables e innovadores según las necesidades de los mercados. Dentro del ámbito nutricional de los alimentos, es fundamental considerar el enfoque planteado por la Organización de las naciones Unidadas (ONU), que en la actualidad 3 de cada 5 muertes en el mundo son responsabilidad de “enfermedades no transmisibles”, dentro de las cuales destacan la obesidad, diabetes tipo 2 y enfermedades cardio-vasculares, todas ellas relacionanadas con una dieta poco saludable. En éste contexto, la leche y los productos lácteos se encuentran en una excelente posición gracias a su composición nutricional, especialmente en cuanto a la calidad de sus ácidos grasos, proteínas y minerales. Sólo tomando en cuenta los ácidos grasos, la leche contiene más de 400 tipos diferentes y aunque la mayor parte de ellos son saturados (65%), contiene además cantidades importantes de ácido grasos mono y poli-insaturados junto con otros ácidos grasos muy especiales gracias a sus beneficios en salud humana como el ácido linoleico conjugado (CLA) y ácido butírico. Considerando la evidencia reciente que apunta a redefinir los efectos de los ácidos grasos saturados de la leche en la salud humana y las evidencias ya conocidas de los efectos beneficiosos de los ácidos grasos poli-insaturados y otros como los CLA, hacen de la leche y productos lácteos una excelente fuente nutricional de ácidos grasos fundamentales en la salud humana.Proyecto financiado por la Región de los Ríos “Desarrollo de una línea base para la potencial generación de productos lácteos diferenciados y protocolos de producción de leche y derivados de alto valor nutricional”, a través del Fondo de Fomento al Desarrollo Científico y Tecnológico (FONDEF).Peer reviewe

Rga6 is a Rho GAP involved in fission yeast polarized growth

Resumen del póster presentado al American Society for Cell Biology (ASCB) Annual Meeting: "Cell Biology", celebrado en San Diego, California (US) del 12 al 16 de diciembre de 2015.Fission yeast Cdc42 is essential for polarized growth and the maintenance of cell dimensions and cylindrical morphology. This GTPase is positively regulated by the GEFs Scd1 and Gef1 and negatively regulated by the GAP Rga4. This study establishes that the protein Rga6 is also a Cdc42 GAP that collaborates with Rga4 in the maintenance of fission yeast shape and the restriction of growth to the tip area. Cells lacking Rga6 are viable but slightly shorter and broader than wild type, and cells lacking simultaneously both GAPs are rounded. In these cells, active Cdc42 is observed all along the membrane. Overexpression of rga6+ for brief periods of time (12-20h) causes cells to elongate, and grow in a monopolar way, as does overexpression of Rga4, and for longer times is deleterious. Rga6 localizes to the plasma membrane forming clusters which are different from those formed by Rga4. Rga6 clusters are very dynamic and move by lateral diffusion. A polybasic region at the Rga6 C-terminus is responsable for its membrane localization. Rga6-GFP fluorescence is considerably reduced at the growing tips and this reduction is dependent on the N-terminal region of Rga6 and on the actin cables made by the formin For3. We propose here that Rga6 participates in the regulation of active Cdc42 localization and in the amplitude of active Cdc42 oscillations at the cell tips.Peer Reviewe

Assessing the effect of the functional dairy products through the changes in potential health biomarkers

Resumen del trabajo presentado al 12th Euro Fed Lipid Congress: "Oils, Fats and Lipids: From Lipidomics to Industrial Innovation" celebrado en Montpellier (Francia) del 14 al 17 de septiembre de 2014.Fats and oils are one of the most important components determining the nutritional and technological quality of foods. In dairy products, the different lipid classes and fatty acid (FA) compounds (mono- and poly-unsaturated, cis and trans, conjugated, short- and medium-chain saturated and branched FA, phospholipids, cholesterol, etc.) are potentially involved as positive or negative factors in the health of human consumers. Enhancement of healthy compounds such as conjugated linoleic acid (CLA) (or their physiological precursor trans-vaccenic acid) and omega-3 FA, phospholipids and reduction of cholesterol and trans FA are promising avenues for improving the FA profiles of dairy foods. Lipid composition of milk fat can be improved both through the diet fed to ruminants by supplying them with oilseeds or PUFA-rich oils or by using probiotic microorganisms with the ability to produce CLA or by incorporating lipid isolates from milk fat globule membrane that contains minor compounds of considerable health value such as phospho- and sphingolipids. In our lab we have developed those three lines of study: 1A) CLA-enriched milk powder reverses hypercholesterolemic risk factors in hamsters. 1B) Cheese with reduced total SFA content and naturally enriched PUFA profile (high omega-3 and CLA) targeted for a healthy functional food development. i) Preclinical evaluation of the physiological effects on healthy Wistar male rats. ii) A prospective, randomized, double-blind, placebo-controlled clinical trial on 62 human overweight/obese and dyslipidemic volunteers. Changes in plasma lipid profile as well as body weight change and body composition had been thoroughly monitorized. 2- Bifidobacterial strains isolated from human breast milk are able to produce CLA and CLNA in reconstituted skim milk-based medium. 3- Skim milk fortified with buttermilk affects the plasma phospholipid and fatty acid composition in healthy subjects.Peer Reviewe