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Ferruzza S.,National Research Institute on Food and Nutrition INRAN
Toxicology in vitro : an international journal published in association with BIBRA | Year: 2012

The Caco-2 cell line spontaneously differentiates into polarised enterocytes expressing high levels of brush border enzymes typical of small intestinal epithelial cells (peptidases, alkaline phosphatase, disaccharidases). The activities of these enzymes gradually increase after cell confluence reaching a plateau after 2-3 weeks of culture and can be used as reliable markers to evaluate differentiation of Caco-2 cells. We have developed a rapid in situ method on live cells to measure activities of alkaline phosphatase, alanyl amino peptidase and sucrase. The substrates were added to the apical compartment of confluent cells maintained for 8, 15 and 21 days on polycarbonate filter inserts and sampling was performed at time intervals. Alkaline phosphatase and alanyl aminopeptidase were assayed using as substrates p-Nitrophenyl phosphate and alanine-p-nitroanilide, respectively, and the yellow product detected spectrophotometrically at 405 nm. Sucrase activity was measured as the release of glucose from sucrose using a fluorimetric assay (Amplex® Red Glucose Assay Kit) in which H(2)O(2), produced by the coupled glucose oxidase/horseradish peroxidase reactions, oxidises the colourless reagent to red-fluorescent resorufin. All these assays are rapid and reproducible and can easily be adapted to robotised high throughput platforms. Copyright © 2011 Elsevier Ltd. All rights reserved. Source


Ferruzza S.,National Research Institute on Food and Nutrition INRAN
Toxicology in vitro : an international journal published in association with BIBRA | Year: 2012

The human intestinal Caco-2 cell line still represents the best available in vitro model of absorptive enterocytes, despite its origin from a colon adenocarcinoma. Caco-2 cells seeded on filter inserts undergo in culture a process of spontaneous differentiation that leads to the formation, after two to three weeks, of a monolayer of polarized cell, coupled by tight junctions and expressing several morphological and functional features of small intestinal enterocytes. The medium normally used for differentiation of Caco-2 cells contains a supplement of foetal bovine serum (FBS) in both the apical (AP) and basolateral (BL) compartments. The use of FBS as cell culture media supplement has been frequently and increasingly questioned on scientific and also on ethical grounds. We have shown that addition of serum only to the BL medium (asymmetric protocol) appears to be sufficient to allow differentiation of Caco-2 cells, as monitored by morphology, monolayer permeability and alkaline phosphatase activity, compared to standard conditions using 10% FBS supplement in both AP and BL media (asymmetric protocol). Although not eliminating the use of FBS, its addition only in the BL medium results in more physiological conditions for differentiation and in a significant reduction of its use. Copyright © 2012 Elsevier Ltd. All rights reserved. Source


Rossi C.,National Research Institute on Food and Nutrition INRAN
Toxicology in vitro : an international journal published in association with BIBRA | Year: 2012

Dietary retinoid bioavailability involves the interplay of the intestine (transport and metabolism) and the liver (secondary metabolism). To reproduce these processes in vitro, differentiated human intestinal Caco-2/TC7 cells were co-cultured with two hepatocyte cell lines. Murine 3A cells and the more highly differentiated human HepaRG hepatocytes were both shown to respond to β-carotene (BC) and retinol (ROH) treatment by secreting Retinol Binding Protein 4 (RBP4). In co-culture experiments, Caco-2/TC7 were differentiated on filter inserts and transferred for the time of the experiment to culture wells containing confluent 3A or differentiated HepaRG cells. Functionality of the co-cultures was assayed using as endpoints the retinol-dependent secretion of RBP4 and the retinoic acid-dependent induction of CYP26A1 in hepatocytes. BC and ROH added to intestinal Caco-2/TC7 induced a reduction in intracellular RBP4 levels in the underlying hepatocytes and its secretion into the medium. HepaRG hepatocytes were also shown to up-regulate the expression of CYP26A1 mRNA in response to retinoid treatment. This in vitro model represents a useful tool to analyze the absorption and metabolism of retinoids and could be further developed to investigate other dietary compounds and molecules of pharmacological interest. Copyright © 2012 Elsevier Ltd. All rights reserved. Source


Cubadda F.,Istituto Superiore di Sanita | Ciardullo S.,Istituto Superiore di Sanita | D'Amato M.,Istituto Superiore di Sanita | Raggi A.,Istituto Superiore di Sanita | And 2 more authors.
Journal of Agricultural and Food Chemistry | Year: 2010

Seven hundred and twenty-six samples of wheat grains from the majority of Italian agricultural areas were pooled into 141 composite samples, homogeneous with respect to geographical origin and wheat variety. The average arsenic concentration of the pooled samples was 9 ng g-1, with a range of 2-55 ng g-1 (dry weight basis). The spread of arsenic concentrations (coefficient of variation of 91%) was related to spatial variability associated with geochemical and environmental factors. Temporal variability was investigated by a 3-year longitudinal study on 7 wheat cultivars grown in 22 areas of central and northern Italy. Average year-to-year variation in arsenic levels was low, and the average of the coefficients of variation was 23%. These results show that mapping of phytoavailable arsenic in agricultural soils can be done by measuring arsenic concentration in representative samples of wheat grains. Arsenic speciation in the grain showed that As(III) and As(V) were the major As compounds, highlighting the importance of wheat as a source of inorganic arsenic in the diet. © 2010 American Chemical Society. Source


Pecorelli A.,University of Siena | Leoni G.,National Research Institute on Food and Nutrition INRAN | Cervellati F.,University of Ferrara | Canali R.,National Research Institute on Food and Nutrition INRAN | And 8 more authors.
Mediators of Inflammation | Year: 2013

Rett syndrome (RTT) is mainly caused by mutations in the X-linked methyl-CpG binding protein (MeCP2) gene. By binding to methylated promoters on CpG islands, MeCP2 protein is able to modulate several genes and important cellular pathways. Therefore, mutations in MeCP2 can seriously affect the cellular phenotype. Today, the pathways that MeCP2 mutations are able to affect in RTT are not clear yet. The aim of our study was to investigate the gene expression profiles in peripheral blood lymphomonocytes (PBMC) isolated from RTT patients to try to evidence new genes and new pathways that are involved in RTT pathophysiology. LIMMA (Linear Models for MicroArray) and SAM (Significance Analysis of Microarrays) analyses on microarray data from 12 RTT patients and 7 control subjects identified 482 genes modulated in RTT, of which 430 were upregulated and 52 were downregulated. Functional clustering of a total of 146 genes in RTT identified key biological pathways related to mitochondrial function and organization, cellular ubiquitination and proteosome degradation, RNA processing, and chromatin folding. Our microarray data reveal an overexpression of genes involved in ATP synthesis suggesting altered energy requirement that parallels with increased activities of protein degradation. In conclusion, these findings suggest that mitochondrial-ATP-proteasome functions are likely to be involved in RTT clinical features. © 2013 Alessandra Pecorelli et al. Source

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