Histidine Prevents Cu-Induced Oxidative Stress and the Associated Decreases in mRNA from Encoding Tight Junction Proteins in the Intestine of Grass Carp (Ctenopharyngodon idella).

Copper (Cu) is a common heavy metal pollutant in aquatic environments that originates from natural as well as anthropogenic sources. The present study investigated whether Cu causes oxidative damage and induces changes in the expression of genes that encode tight junction (TJ) proteins, cytokines and antioxidant-related genes in the intestine of the grass carp (Ctenopharyngodon idella). We demonstrated that Cu decreases the survival rate of fish and increases oxidative damage as measured by increases in malondialdehyde and protein carbonyl contents. Cu exposure significantly decreased the expression of genes that encode the tight junction proteins, namely, claudin (CLDN)-c, -3 and -15 as well as occludin and zonula occludens-1, in the intestine of fish. In addition, Cu exposure increases the mRNA levels of the pro-inflammatory cytokines, specifically, IL-8, TNF-α and its related signalling factor (nuclear factor kappa B, NF-κB), which was partly correlated to the decreased mRNA levels of NF-κB inhibitor protein (IκB). These changes were associated with Cu-induced oxidative stress detected by corresponding decreases in glutathione (GSH) content, as well as decreases in the copper, zinc-superoxide dismutase (SOD1) and glutathione peroxidase (GPx) activities and mRNA levels, which were associated with the down-regulated antioxidant signalling factor NF-E2-related factor-2 (Nrf2) mRNA levels, and the Kelch-like-ECH-associated protein1 (Keap1) mRNA levels in the intestine of fish. Histidine supplementation in diets (3.7 up to 12.2 g/kg) blocked Cu-induced changes. These results indicated that Cu-induced decreases in intestinal TJ proteins and cytokine mRNA levels might be partially mediated by oxidative stress and are prevented by histidine supplementation in fish diet

A NOVEL METHOD FOR DIAGNOSING PILE INTEGRITY USING BACK-PROPAGATION ARTIFICIAL NEURAL NETWORKS

Foundation is the utmost important element of a building, especially for high-rise structures. Any defect or damage of the pile segments can seriously destroy the building structure above. However, the satisfactory assessment of such pile is by no means an easy task. It is important to develop the efficient technique to determine the accurate integrity of foundation pile. In this paper the artificial neural network (ANN) program based on the low strain dynamic test is presented for diagnosing pile integrity. The records of pile integrity testing as well as the length, cross-sectional area of pile and wave velocity are identified to be the most reliable and are used as the input data set in the network. The back-propagation learning algorithm is employed to train the networks for extracting knowledge from training examples. In order to determine the level of accuracy of the pile integrity, the novel approach is proposed containing two back-propagation ANN models. The classification of pile integrity can be determined using the first model. Then the second model is responsible for the further investigation of the exact degree of pile defect and corresponding location. The actual piles are used to illustrate the process. After the diagnosis for defect type, a total of thirty-six patterns of neck pile were particularly selected for the training while four others for testing. The results from the testing phase indicate that the neural network was successful in modeling the relationship between foundation pile integrity and the other parameters and generally gave the reasonable predictions

Dietary leucine improves flesh quality and alters mRNA expressions of Nrf2-mediated antioxidant enzymes in the muscle of grass carp (Ctenopharyngodon idella)

The objective of the study was to assess the influence of dietary leucine on flesh quality and the mRNA level of Nrf2-mediated antioxidant enzymes in the muscle of grass carp (Ctenopharyngodon idella). A total of 540 grass carp (295.85 +/- 2.07 g) were fed six diets with graded levels of leucine (7.1, 8.9, 11.0, 13.3, 15.2 and 17.1 g kg(-1) diet) for eight weeks. The result indicated that muscle protein, lipid content, muscle EAA (essential amino acid) levels, shear force, and hydroxyproline concentrationwere significantly improved by 11.0-17.1, 8.9-17.1, 8.9-17.1, 11.0-13.3, 8.9-13.3 g leucine kg(-1) diet supplementations, respectively. On the other hand, cooking loss, activities of cathepsin L, malondialdehyde and protein carbonyl contents exhibited an opposite tendency. Moreover, the results indicated that compared with leucine unsupplemented group (7.1 g leucine kg(-1) diet), 8.9-17.1, 11.0-17.1, 11.0-15.2 and 8.9-15.2 g kg(-1) leucine supplementations significantly enhanced the activities of copper/zinc superoxide dismutase (SOD1), catalase (CAT) and glutathione peroxidase (GPx), and glutathione content, respectively. Furthermore, the changes in the relative mRNA expressions of SOD1, CAT, GPx, nuclear factor erythroid 2-related factor 2 (Nrf2), target of rapamycin (TOR), and ribosomal protein S6 kinase beta-1 (S6K1) induced by leucine were similar to those noted in their enzyme activities. Conversely, the mRNA levels of Kelch-like ECH-associated protein 1 (Keap1) were significantly down-regulated by leucine supplementation. In conclusion, optimum leucine improved flesh quality, partly due to the enhancement of antioxidant capacity through regulating antioxidant-related signaling molecule. Based on muscle MDA, the optimum dietary leucine requirements of young grass carp (296-690 g) for flesh quality were estimated to be 12.8 g kg(-1) diet, corresponding to 39.3 g kg(-1) of dietary protein. (C) 2015 Elsevier B.V. All rights reserved

Copper-induced tight junction mRNA expression changes, apoptosis and antioxidant responses via NF-kappa B, TOR and Nrf2 signaling molecules in the gills of fish: Preventive role of arginine

This study explored the possible preventive effects of dietary arginine on copper (Cu)-induced tight junction mRNA expression changes, apoptosis and antioxidant responses in the gills of young grass carp (Ctenopharyngodon idella). The results indicated that exposure to 0.7 mg/L (11.01 mu mol/L) Cu for 96h induced the production of reactive oxygen species (ROS), thereby increasing protein oxidation, lipid peroxidation and DNA damage in the gills of fish. However, these oxidative effects were prevented by arginine supplementation. Arginine also prevented the toxic effects of Cu on the activities of copper/zinc superoxide dismutase (SOD1), glutathione-S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR) and the glutathione (GSH) content (P0.05). These results indicated that Cu exposure induced apoptosis and antioxidant system and tight junction mRNA changes in the fish gills, which could be completely blocked by dietary arginine pre-supplementation. (C) 2014 Elsevier B.V. All rights reserved

Cu induces an increase in NF-κB (A) and IκB (B) mRNA levels in fish intestine.

<p>The protocol and indications are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0157001#pone.0157001.g003" target="_blank">Fig 3</a>. NF-κB, nuclear factor kappa B; IκB, inhibitor protein-κB.</p

Composition and nutrient content of the basal diet.

<p>Composition and nutrient content of the basal diet.</p

Quadratic regression of the percentage of weight gain of grass carps as a function of histidine dose.

<p>Quadratic regression of the percentage of weight gain of grass carps as a function of histidine dose.</p