117 research outputs found

    Digestive Enzymes in the Crayfish Cherax albidus: Polymorphism and Partial Characterization

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    We will deal with the partial characterization and the activity of the following digestive enzymes: amylase, pectinase, alginase, lipase, and protease present in the digestive tract of juvenile freshwater crayfishCherax albidus. Gastric juices, the hepatopancreas, and the intestine were sampled for enzyme analysis. Among carbohydratases, amylase activity was the highest. It was significantly higher in the intestine than in the gastric juice and hepatopancreas. Lipase activity was significantly higher in the hepatopancreas and the intestine compared to the gastric juice. Both alkaline and acid proteases were found. Alkaline proteases were characterized by employing specific protease inhibitors. Both trypsin and chymotrypsin activity was detected. The majority of alkaline protease activity was ascribable to trypsin. Several isoforms of digestive enzymes were identified by gel electrophoresis. This work provides basic information to study the digestive abilities of crayfish

    FAIM-L - SIVA-1 : Two Modulators of XIAP in Non-Apoptotic Caspase Function

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    Apoptosis is crucial for the correct development of the nervous system. In adulthood, the same protein machinery involved in programmed cell death can control neuronal adaptiveness through modulation of synaptic pruning and synaptic plasticity processes. Caspases are the main executioners in these molecular pathways, and their strict regulation is essential to perform neuronal remodeling preserving cell survival. FAIM-L and SIVA-1 are regulators of caspase activation. In this review we will focus on FAIM-L and SIVA-1 as two functional antagonists that modulate non-apoptotic caspase activity in neurons. Their participation in long-term depression and neurite pruning will be described in base of the latest studies performed. In addition, the association of FAIM-L non-apoptotic functions with the neurodegeneration process will be reviewed

    Development of Biopolymers as Binders for Feed for Farmed Aquatic Organisms

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    Feed for farmed aquatic organisms should guarantee reasonable degree of stability in aquatic medium, long enough for organisms to consume it. Indeed, there is a general complaint about the loss of nutritional and attractive properties upon exposure of a diet to water. Natural substances able to generate firm pellet feed are therefore highly sought. Such binders should improve the stability of feed, be low cost, and hopefully make and extra source of energy. Biopolymers, have properties that make them suitable for use as aquatic feed binders. Some biopolymers are derived from biomass, biodegradable and renewable. The purpose of this chapter is therefore to review recent reports and progress surrounding the possible employment of sustainable biopolymers as binders for feed for farmed aquatic organisms

    Influence of polyphenols from olive mill wastewater on the gastrointestinal tract, alveolar macrophages and blood leukocytes of pigs

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    In the last years, great importance has been given to the beneficial effects of polyphenols. Among the most relevant health promoting effects, there is the capacity to reduce the amount of free radicals and stimulate the immune response. In this study, polyphenols extracted from olive mill wastewater (OMWW), were fed to adult 'Casertana' pigs during the finishing period. No significant differences in the length of the jejunum-ileum villi and the depth of the colon crypts were detected between control and polyphenols fed pigs. Instead, intra-epithelial and lamina propria leukocytes were more abundant in pigs fed polyphenols (p < .05). Cyclooxygenase-2 immunoreactivity in the gastrointestinal tract, employed as marker of inflammation, was more intense in the control group. Superoxide anion production in primary cell cultures of both blood leukocytes and alveolar macrophages was lower in pigs fed polyphenols (p < .05). Taken together these data indicate that, according to our in vitro studies, OMWW polyphenols seem to be potent antioxidants, while the interpretation of the in vivo experiments is more problematic and further studies are necessary on the interactions between bioactive feed compounds and intestinal status. Such studies can contribute to a better understanding of both positive and negative interactions in vivo and to the identification of new functional feeds.HIGHLIGHTS The effects of polyphenols extracted from olive mill wastewater (OMWW) have been studied in pigs. Gut morphology, inflammation and immune response were investigated. OMWW polyphenols act as potent antioxidants

    Host defense responses to infection by Mycobacterium tuberculosis. Induction of IRF-1 and a serine protease inhibitor.

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    Alveolar macrophages and newly recruited monocytes are targets of infection by Mycobacterium tuberculosis. Therefore, we examined the expression of interferon regulatory factor 1 (IRF-1), which plays an important role in host defense against M. tuberculosis, in undifferentiated and differentiated cells. Infection induced IRF-1 in both. IRF-1 from undifferentiated, uninfected monocytic cell lines was modified during extraction to produce specific species that were apparently smaller than intact IRF-1. After infection by M. tuberculosis or differentiation, intact IRF-1 was recovered. Subcellular fractions were assayed for the ability to modify IRF-1 or inhibit its modification. A serine protease on the cytoplasmic surface of an organelle or vesicle in the "lysosomal/mitochondrial" fraction from undifferentiated cells was responsible for the modification of IRF-1. Thus, the simplest explanation of the modification is cleavage of IRF-1 by the serine protease. Recovery of intact IRF-1 correlated with induction of a serine protease inhibitor that was able to significantly reduce the modification of IRF-1. The inhibitor was present in the cytoplasm of M. tuberculosis-infected or -differentiated cells. It is likely that induction of both IRF-1 and the serine protease inhibitor in response to infection by M. tuberculosis represent host defense mechanisms

    Influence of Egr-1 in cardiac tissue-derived mesenchymal stem cells in response to glucose variations

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    Mesenchymal stem cells (MSCs) represent a promising cell population for cell therapy and regenerative medicine applications. However, how variations in glucose are perceived by MSC pool is still unclear. Since, glucose metabolism is cell type and tissue dependent, this must be considered when MSCs are derived from alternative sources such as the heart. The zinc finger transcription factor Egr-1 is an important early response gene, likely to play a key role in the glucose-induced response. Our aim was to investigate how short-term changes in in vitro glucose concentrations affect multipotent cardiac tissue-derived MSCs (cMSCs) in a mouse model of Egr-1 KO (Egr-1-/-). Results showed that loss of Egr-1 does not significantly influence cMSC proliferation. In contrast, responses to glucose variations were observed in wt but not in Egr-1 -/- cMSCs by clonogenic assay. Phenotype analysis by RT-PCR showed that cMSCs Egr-1-/- lost the ability to regulate the glucose transporters GLUT-1 and GLUT-4 and, as expected, the Egr-1 target genes VEGF, TGFβ-1, and p300. Acetylated protein levels of H3 histone were impaired in Egr-1-/- compared to wt cMSCs. We propose that Egr-1 acts as immediate glucose biological sensor in cMSCs after a short period of stimuli, likely inducing epigenetic modifications. © 2014 Daniela Bastianelli et al

    Impact of Mycobacterium tuberculosis RD1-locus on human primary dendritic cell immune functions

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    Modern strategies to develop vaccines against Mycobacterium tuberculosis (Mtb) aim to improve the current Bacillus Calmette-Guerin (BCG) vaccine or to attenuate the virulence of Mtb vaccine candidates. In the present study, the impact of wild type or mutated region of difference 1 (RD1) variants on the immunogenicity of Mtb and BCG recombinants was investigated in human primary dendritic cells (DC). A comparative analysis of transcriptome, signalling pathway activation, maturation, apoptosis, cytokine production and capacity to promote Th1 responses demonstrated that DC sense quantitative and qualitative differences in the expression of RD1-encoded factors - ESAT6 and CFP10 - within BCG or Mtb backgrounds. Expansion of IFN-γ producing T cells was promoted by BCG::RD1-challenged DC, as compared to their BCG-infected counterparts. Although Mtb recombinants acted as a strong Th-1 promoting stimulus, even with RD1 deletion, the attenuated Mtb strain carrying a C-terminus truncated ESAT-6 elicited a robust Th1 promoting phenotype in DC. Collectively, these studies indicate a necessary but not sufficient role for the RD1 locus in promoting DC immune-regulatory functions. Additional mycobacterial factors are likely required to endow DC with a high Th1 polarizing capacity, a desirable attribute for a successful control of Mtb infection
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