Lactobacillus delbrueckii subsp lactis (strain CIDCA 133) resists the antimicrobial activity triggered by molecules derived from enterocyte-like Caco-2 cells

Aim: The aim of the present study was to assess the ability of a potentially probiotic strain to resist, in vitro, the effect of intestinal antimicrobial molecules. Methods and results: Strain CIDCA 133 of Lactobacillus delbrueckii subsp lactis was studied. Lactobacillus delbrueckii subsp bulgaricus as well as other gram-positive and gram-negative bacteria were used for comparison purposes. The effect of different antimicrobial extracts was determined by diffusion assays, viable counts and growth kinetics. Human-defensins (hβD1 and hβD2) were also included in the study. Two types of cellular fractions from Caco-2 cells were tested: (i) cytosolic fractions, obtained by sonication of cultured human enterocytes and (ii) cationic fraction, obtained by batch extraction of the cytosolic fraction with a weak cation exchange resin. In addition, the effect of Caco-2-secreted factors was studied. Strain CIDCA 133 was neither inhibited by Caco-2 secreted, cytosolic nor cationic fractions. Of note, human-defensins were inactive against strain CIDCA 133. In contrast, a related lactobacilli: Lactobacilli delbrueckii subsp bulgaricus (strain CIDCA 331) and other species of gram-positive or gram-negative bacteria were strongly inhibited. Conclusions: Strain CIDCA 133 is able to survive and grow in the presence of enterocyte-derived antimicrobial molecules. This ability is not a general property of lactobacilli. Significance and Impact of the Study: Results could provide a new insight into the mechanisms of the probiotic effect and encourage further studies on this field. Resistance to antimicrobial peptides can be relevant to understand the interaction of potentially probiotic strains with the host's immune system. This ability can be also relevant as a selection criterion for new probiotic strains.Facultad de Ciencias Exacta

Short transmembrane domains with high-volume exoplasmic halves determine retention of Type II membrane proteins in the Golgi complex

It is still unclear why some proteins that travel along the secretory pathway are retained in the Golgi complex whereas others make their way to the plasma membrane. Recent bioinformatic analyses on a large number of single-spanning membrane proteins support the hypothesis that specific features of the transmembrane domain (TMD) are relevant to the sorting of these proteins to particular organelles. Here we experimentally test this hypothesis for Golgi and plasma membrane proteins. Using the Golgi SNARE protein Sft1 and the plasma membrane SNARE protein Sso1 from Saccharomyces cerevisiae as model proteins, we modified the length of their TMDs and the volume of their exoplasmic hemi-TMD, and determined their subcellular localization both in yeast and mammalian cells. We found that short TMDs with high-volume exoplasmic hemi-TMDs confer Golgi membrane residence, whereas TMDs with low-volume exoplasmic hemi-TMDs, either short or long, confer plasma membrane residence to these proteins. Results indicate that the shape of the exoplasmic hemi-TMD, in addition to the length of the entire TMD, determine retention in the Golgi or exit to the plasma membrane of Type II membrane proteins.Fil: Quiroga, Rodrigo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Quimica Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Química Biológica de Córdoba (p); ArgentinaFil: Trenchi, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Química Biológica de Córdoba (p); Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Quimica Biológica; ArgentinaFil: Gonzalez Montoro, Ayelén. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Quimica Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Química Biológica de Córdoba (p); ArgentinaFil: Valdez, Javier Esteban. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Quimica Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Química Biológica de Córdoba (p); ArgentinaFil: Maccioni, Hugo Jose Fernando. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Química Biológica de Córdoba (p); Argentin

Lactobacillus delbrueckii subsp lactis (strain CIDCA 133) resists the antimicrobial activity triggered by molecules derived from enterocyte-like Caco-2 cells

Aim: The aim of the present study was to assess the ability of a potentially probiotic strain to resist, in vitro, the effect of intestinal antimicrobial molecules. Methods and results: Strain CIDCA 133 of Lactobacillus delbrueckii subsp lactis was studied. Lactobacillus delbrueckii subsp bulgaricus as well as other gram-positive and gram-negative bacteria were used for comparison purposes. The effect of different antimicrobial extracts was determined by diffusion assays, viable counts and growth kinetics. Human-defensins (hβD1 and hβD2) were also included in the study. Two types of cellular fractions from Caco-2 cells were tested: (i) cytosolic fractions, obtained by sonication of cultured human enterocytes and (ii) cationic fraction, obtained by batch extraction of the cytosolic fraction with a weak cation exchange resin. In addition, the effect of Caco-2-secreted factors was studied. Strain CIDCA 133 was neither inhibited by Caco-2 secreted, cytosolic nor cationic fractions. Of note, human-defensins were inactive against strain CIDCA 133. In contrast, a related lactobacilli: Lactobacilli delbrueckii subsp bulgaricus (strain CIDCA 331) and other species of gram-positive or gram-negative bacteria were strongly inhibited. Conclusions: Strain CIDCA 133 is able to survive and grow in the presence of enterocyte-derived antimicrobial molecules. This ability is not a general property of lactobacilli. Significance and Impact of the Study: Results could provide a new insight into the mechanisms of the probiotic effect and encourage further studies on this field. Resistance to antimicrobial peptides can be relevant to understand the interaction of potentially probiotic strains with the host's immune system. This ability can be also relevant as a selection criterion for new probiotic strains.Facultad de Ciencias Exacta

Solid phase extraction of arsenic on modified MWCNT/Fe3O4 magnetic hybrid nanoparticles from copper ores samples with ETAAS determination

A simple procedure for the synthesis of magnetic hybrid nanoparticles (MHNP) was developed by combining multi-walled carbon nanotubes modified by microwave energy and magnetic iron oxide nanoparticles. MHNP were introduced as sorbents in a magnetic solid phase extraction methodology for the total Arsenic determination in copper ore samples. Arsenic is penalized contaminant element in copper ores. Arsenic was determined by electrothermal atomic absorption spectrometry with a reduced temperature program. Arsenic adsorption corresponded to 96 - 104%, at ug g−1 levels. After a variable screening stage using a Placket-Burman (PBD) experimental design, the developed methodology was optimized using a Box-Behnken experimental design. Based on the optimal working parameters, a detection limit of 30 ng L−1 was reached, with a relative standard deviation of 7.1% and a preconcentration factor (PF) of 50. The Certified Geochem Base Metal Reference Material Product Code GBM900-10 was analyzed for the validation stage.Fil: Villafañe Salinas, Manuel Gastón. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Bazán, Vanesa. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; ArgentinaFil: Brandaleze, Elena. Universidad Tecnológica Nacional; ArgentinaFil: López, Ayelén. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; ArgentinaFil: Pacheco, Pablo Hugo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Maratta Martínez, Sergio Ariel. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentin

Development and characterization of iron-pectin beads as a novel system for iron delivery to intestinal cells

Iron deficiency is the most common nutritional deficit worldwide. The goal of this work was to obtain iron-pectin beads by ionic gelation and evaluate their physiological behavior to support their potential application in the food industry. The beads were firstly analyzed by scanning electronic microscopy, and then physical-chemically characterized by performing swelling, thermogravimetric, porosimetry, Mössbauer spectroscopy and X-ray fluorescence analyses, as well as by determining the particle size. Then, physiological assays were carried out by exposing the beads to simulated gastric and intestinal environments, and determining the iron absorption and transepithelial transport into Caco-2/TC7 cells. Iron-pectin beads were spherical (diameter 1-2 mm), with high density (1.29 g/mL) and porosity (93.28%) at low pressure, indicating their high permeability even when exposed to low pressure. Swelling in simulated intestinal medium (pH 8) was higher than in simulated gastric medium. The source of iron [FeSO4 (control) or iron-pectin beads] did not have any significant effect on the mineral absorption. Regarding transport, the iron added to the apical pole of Caco-2/TC7 monolayers was recovered in the basal compartment, and this was proportional with the exposure time. After 4 h of incubation, the transport of iron arising from the beads was significantly higher than that of the iron from the control (FeSO4). For this reason, iron-pectin beads appear as an interesting system to overcome the low efficiency of iron transport, being a potential strategy to enrich food products with iron, without altering the sensory properties.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Development and characterization of iron-pectin beads as a novel system for iron delivery to intestinal cells

Iron deficiency is the most common nutritional deficit worldwide. The goal of this work was to obtain iron-pectin beads by ionic gelation and evaluate their physiological behavior to support their potential application in the food industry. The beads were firstly analyzed by scanning electronic microscopy, and then physical-chemically characterized by performing swelling, thermogravimetric, porosimetry, Mössbauer spectroscopy and X-ray fluorescence analyses, as well as by determining the particle size. Then, physiological assays were carried out by exposing the beads to simulated gastric and intestinal environments, and determining the iron absorption and transepithelial transport into Caco-2/TC7 cells. Iron-pectin beads were spherical (diameter 1-2 mm), with high density (1.29 g/mL) and porosity (93.28%) at low pressure, indicating their high permeability even when exposed to low pressure. Swelling in simulated intestinal medium (pH 8) was higher than in simulated gastric medium. The source of iron [FeSO4 (control) or iron-pectin beads] did not have any significant effect on the mineral absorption. Regarding transport, the iron added to the apical pole of Caco-2/TC7 monolayers was recovered in the basal compartment, and this was proportional with the exposure time. After 4 h of incubation, the transport of iron arising from the beads was significantly higher than that of the iron from the control (FeSO4). For this reason, iron-pectin beads appear as an interesting system to overcome the low efficiency of iron transport, being a potential strategy to enrich food products with iron, without altering the sensory properties.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Capacidad probiótica de la cepa CIDCA 133 (Lactobacillus delbrueckii subsp lactis): un recorrido desde modelos in vitro a in vivo

Facultad de Ciencias Exacta

Stress response elements in the ovary and its implication in ovarian pathophysiology in cattle

En respuesta a varios estresores, la hormona adrenocorticotrópica estimula la síntesis y secreción de los glucocorticoides, los cuales pueden afectar la reproducción directamente por acción sobre el eje hipotálamo-hipófisis-ovario. En este sentido, es importante destacar que la ovulación ha sido descripta como un proceso inflamatorio localizado, donde una sucesión de eventos lleva a la degradación proteolítica de un punto específico de la pared folicular para permitir la salida del ovocito. Por lo tanto, el cortisol liberado a causa del estrés podría actuar a nivel del sitio ovulatorio inhibiendo la ovulación al producir efectos antiinflamatorios locales. Si bien no ha sido demostrado que el ovario sea capaz de producir glucocorticoides de novo, la hormona adrenocorticotrópica, a través de su unión a los receptores de melanocortinas en el ovario bovino, es capaz de estimular la secreción de hormonas esteroides tanto in vivo como in vitro, principalmente la secreción de cortisol, y producir cambios en la expresión de las enzimas 11β-hidroxiesteroide deshidrogenasas responsables de la activación/inactivación del cortisol. Nuestros resultados indican que la hormona adrenocorticotrópica puede estar implicada en los mecanismos regulatorios relacionados a la función ovárica asociados con la ovulación, la esteroidogénesis y la fisiopatología de diferentes enfermedades reproductivas en bovinos.In response to stressors, adrenocorticotropic hormone stimulates the synthesis and secretion of glucocorticoids, which can affect reproduction acting on the hypothalamic-pituitary-ovarian axis. In this sense, that ovulation has been described as a localized inflammatory process, where a sequence of events leading to proteolytic degradation of a specific point of the follicular wall to allow the exit of the oocyte. Hence, cortisol released could act in the ovulatory site, inhibiting the ovulation through the production of local anti-inflammatory effects. Although has not been demonstrated that the ovary is able to produce glucocorticoids de novo, adrenocorticotropic hormone, through binding to melanocortin receptors in bovine ovary, it is able to stimulate the secretion of steroid hormones both in vivo and in vitro, mainly cortisol, and produce changes in the expression of 11β-hydroxysteroid dehydrogenase enzymes responsible for the local activation / inactivation of cortisol. Our results indicate that adrenocorticotropic hormone may be involved in regulatory mechanisms related to ovarian function associated with ovulation, ovarian steroidogenesis, luteal function and the pathophysiology of various reproductive diseases in cattle.Sociedad de Ciencias Morfológicas de La Plat

Lead preconcentration by solid phase extraction using oxidized carbon xerogel and spectrophotometric determination with dithizone

The proposed methodology is based on the preconcentration of Pb2+ on oxidized carbon xerogel, a porous material of low density and high surface area. Adsorbed Pb2+ was eluted with HCl, followed by complexion with dithizone in ethanol-water solution and determined by UV-visible spectrophotometry in a continuous flow system (FI). Variables such as pH, type of eluent, eluent concentration, type of complexing solvent, concentration of complexing reagent and flow rates were optimized. The proposed system reached an enrichment factor of 50, with 5 mL of sample. Detection limit was of 0.9 μg L-1, with a precision of 7.8% (n = 10). The proposed system was successfully applied to the determination of Pb in tap water from San Juan City, Argentina.Fil: Maratta Martínez, Sergio Ariel. Universidad Nacional de San Juan. Facultad de Filosofía, Humanidades y Artes. Departamento de Física y Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Vázquez, Sandra. Universidad Nacional de San Juan. Facultad de Filosofía, Humanidades y Artes. Departamento de Física y Química; Argentina. Universidad Nacional de San Juan. Facultad de Filosofía, Humanidades y Artes. Instituto de Ciencias Básicas; ArgentinaFil: López, Ayelén. Universidad Nacional de San Juan. Facultad de Filosofía, Humanidades y Artes. Instituto de Ciencias Básicas; ArgentinaFil: Augusto, Miriam. Universidad Nacional de San Juan. Facultad de Filosofía, Humanidades y Artes. Departamento de Física y Química; Argentina. Universidad Nacional de San Juan. Facultad de Filosofía, Humanidades y Artes. Instituto de Ciencias Básicas; ArgentinaFil: Pacheco, Pablo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin