http://hdl.handle.net/2067/1306 2013-05-18T07:25:22Z 2013-05-18T07:25:22Z Finamore, Alberto Roselli, Marianna Merendino, Nicolò Nobili, Fabio Vignolini, Francesco Mengheri, Elena http://hdl.handle.net/2067/2069 2011-09-26T23:05:35Z 2002-12-31T23:00:00Z

Title: Zinc deficiency suppresses the development of oral tolerance in rats Authors: Finamore, Alberto; Roselli, Marianna; Merendino, Nicolò; Nobili, Fabio; Vignolini, Francesco; Mengheri, Elena Abstract: Oral tolerance is a specific immune unresponsiveness to food antigens to prevent hypersensitivity reactions. We investigated whether zinc deficiency affects oral tolerance. Rats were fed a control (C) or zincdeficient (ZD) diet, or pair-fed (PF) to ZD rats for 28 d. Beginning on d 7, rats were administered ovalbumin (OVA) orally to induce tolerance, or PBS 3 times/wk, and were then immunized by OVA injection. The proliferation of mesenteric lymph node (MLN) and spleen lymphocytes after in vitro OVA stimulation and the delayed-type hypersensitivity were higher in OVA-fed ZD than in OVA-fed C rats and not different between OVA- and PBS-fed ZD rats, indicating a suppression of tolerance. Lymphocyte proliferation did not differ between PF and C rats. Expressions of cytokines involved in oral tolerance, i.e., interleukin (IL)-4, IL-10 and transforming growth factor- , were higher in OVA- than in PBS-fed C rats, but not in ZD rats. Apoptosis was higher in OVA- than in PBS-fed C rats but not different between OVA- and PBS-fed ZD rats. Inflammation and ulcerations that were not present in ZD rats on d 7 (ZD7 ) developed in OVA- or PBS-fed ZD rats. Compared with ZD7 rats, tumor necrosis factor- and cytokine-induced neutrophil chemoattractant were higher in OVA- and PBS-fed ZD rats, whereas interferon- increased only in OVA-fed ZD rats. In conclusion, zinc deficiency suppresses oral tolerance through dysregulation of cytokine expression and lack of antigen-specific clonal deletion. We suggest that abrogation of tolerance may lead to development of mucosal inflammation and damage. Description: L'articolo è disponibile sul sito dell'editore http://jn.nutrition.org

2002-12-31T23:00:00Z Belfiore, Maria Cristina Natoni, Alessandro Barzellotti, Roberta Merendino, Nicolò Pessina, Gloria Gualandi, Giampiero http://hdl.handle.net/2067/2068 2011-09-29T23:05:36Z 2006-12-31T23:00:00Z

Title: Involvement of 5-lipoxygenase in survival of Epstein-Barr virus (EBV)-converted B lymphoma cells Authors: Belfiore, Maria Cristina; Natoni, Alessandro; Barzellotti, Roberta; Merendino, Nicolò; Pessina, Gloria; Gualandi, Giampiero Abstract: Epstein–Barr Virus (EBV) is involved in the progression of lymphomas through still unknown mechanism involving increased resistance to induced apoptosis. We show here that in a set of apoptosis-resistant EBV-converted Burkitt’s lymphoma clones, 5- and 12-lipoxygenases (LOXs) are over-expressed. Further investigations on 5-LOX showed that resistance to apoptosis increases parallely with the expression of 5-lipoxygenase (5-LOX). Inhibitors of 5-LOX: (a) decrease peroxides level, indicating that this enzyme promotes the generation of oxidative stress in EBV+ cells, and (b) potently induce apoptosis in the EBV resistant cell line E2R. 5- and 15-HETE, the products of the 5 and 15-LOXs, respectively, counteract 5-LOX inhibitor induced apoptosis, indicating that products of arachidonate metabolism, rather than peroxides, trigger a signal transduction that is required for survival of the EBV-converted cells. These findings suggest that 5- and, to a lesser extent, other LOXs, that are involved in tumor progression of several cell types, may also participate in lymphomagenesis, especially that EBV-mediated. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com

2006-12-31T23:00:00Z Cimmaruta, Roberta Bondanelli, Paola Ruggi, Alessandra Nascetti, Giuseppe http://hdl.handle.net/2067/1800 2011-09-29T23:05:35Z 2007-12-31T23:00:00Z

Title: Genetic structure and temporal stability in the horse mackerel (Trachurus trachurus) Authors: Cimmaruta, Roberta; Bondanelli, Paola; Ruggi, Alessandra; Nascetti, Giuseppe Abstract: This study aimed at assessing the temporal and spatial genetic structure of the horse mackerel (Trachurus trachurus) using allozymes, within the frame of a multidisciplinary research project directed at the stock assessment of this species. To this end, 19 samples were taken from a large part of the geographical range of the species, providing more than 2200 specimens analysed. Samples from 14 localities were caught twice in different years, so that the temporal stability of their genetic structure could be investigated. The genotypes and the allele frequencies obtained at different times from the same locality were statistically consistent, suggesting that the genetic structure of horse mackerel populations is stable overtime. Allozyme analysis showed that all the horse mackerel populations studied, although geographically separated, were genetically homogeneous and connected by high levels of gene flow. Attempts to highlight subtle genetic structure only revealed a slight differentiation between eastern Mediterranean samples (Ionian and Aegean Seas) versus the western Mediterranean and Atlantic ones, in agreement with the horse mackerel’s migration routes so far identified and with the results obtained using different approaches (parasites as biological tags, otoliths). A further objective of the research was to assess the level of genetic variability in this species. We found very high variability in all the studied samples, among the highest recorded in the literature for many pelagic and demersal fishes. Since the levels of genetic variability are increasingly used as indicators of the state of exploited and human-impacted populations, the results obtained suggested that the biomass depletion suffered by the horse mackerel has not impoverished its genetic resources yet. However, it is worth noting that the significantly lowest values were recorded for the samples from the so-called north-western stock, where the catches are rapidly decreasing since 1996. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com

2007-12-31T23:00:00Z Angeletti, Dario Cimmaruta, Roberta Nascetti, Giuseppe http://hdl.handle.net/2067/1799 2011-09-29T23:05:34Z 2009-12-31T23:00:00Z

Title: Genetic diversity of the killifish Aphanius fasciatus paralleling the environmental changes of Tarquinia salterns habit Authors: Angeletti, Dario; Cimmaruta, Roberta; Nascetti, Giuseppe Abstract: The habitat in the Natural Reserve of the Tarquinia salterns, located on the Tyrrhenian coast of central Italy, has undergone dramatic alterations over the last 10 years. After salt production was terminated in 1997 the site was abandoned until 2002, with consequent degradation of habitat quality and stiffening of the environmental conditions. From 2003 to 2006 ecological rehabilitation of the site was carried out, restoring water circulation to its previous equilibrium. The genetic variation in the killifish Aphanius fasciatus inhabiting the salterns was monitored using allozymes from 1998. The results showed that the genetic variability of the killifish strongly reduced through time: a high number of rare alleles were lost and both heterozygosity and allele richness were significantly decreased. The most recent samples, taken after the ecological restoration, showed that to date the genetic erosion of A. fasciatus gene pool has slowed down, since no significant differences have been detected for any genetic variability parameter. Concerning the mechanisms leading to the impoverishment of the genetic variability, the strong loss of rare alleles suggests a role of genetic drift, which accords with the fluctuation of the effective population size recorded over the period of study and with the low gene flow typical of this species. The low levels of gene flow reported for this species imply that once lost, the genetic variability can rarely be restored through immigration from highly variable populations. Description: L'articolo è disponibile sul sito dell'editore http://www.springerlink.com

2009-12-31T23:00:00Z