A new insight on copper: Promotion of collagen synthesis and myofiber growth and development in juvenile grass carp (Ctenopharyngodon idella).

Copper (Cu) is a trace element, essential for fish growth. In the current study, in addition to growth performance, we first explored the effects of Cu on collagen synthesis and myofiber growth and development in juvenile grass carp (Ctenopharyngodon idella). A total of 1080 fish (11.16 ± 0.01 g) were randomly divided into 6 treatments (3 replicates per treatment) to receive five doses of organic Cu, which were Cu citrate (CuCit) at 0.99 (basal diet), 2.19, 4.06, 6.15, and 8.07 mg/kg, and one dose of inorganic Cu (CuSO4·5H2O at 3.15 mg/kg), for 9 weeks. The results showed appropriate Cu level (4.06 mg/kg) enhanced growth performance, improved nutritional Cu status, and downregulated Cu-transporting ATPase 1 mRNA levels in the hepatopancreas, intestine, and muscle of juvenile grass carp. Meanwhile, collagen content in fish muscle was increased after Cu intake, which was probably due to the following pathways: (1) activating CTGF/TGF-ß1/Smads signaling pathway to regulate collagen transcription; (2) upregulating of La ribonucleoprotein domain family 6 (LARP6) mRNA levels to regulate translation initiation; (3) increasing proline hydroxylase, lysine hydroxylase, and lysine oxidase activities to regulate posttranslational modifications. In addition, optimal Cu group increased myofiber diameters and the frequency of myofibers with diameter >50 µm, which might be associated with upregulation of cyclin B, cyclin D, cyclin E, proliferating cell nuclear antigen, myogenic determining factor (MyoD), myogenic factor 5, myogenin (MyoG), myogenic regulatory factor 4 and myosin heavy chain (MyHC) and downregulation of myostatin mRNA levels, increasing protein levels of MyoD, MyoG and MyHC in fish muscle. Finally, based on percentage weight gain (PWG), serum ceruloplasmin (Cp) activity and collagen content in fish muscle, Cu requirements were determined as 4.74, 4.37 and 4.62 mg/kg diet (CuCit as Cu source) of juvenile grass carp, respectively. Based on PWG and Cp activity, compared to CuSO4·5H2O, the efficacy of CuCit were 131.80% and 115.38%, respectively. Our findings provide new insights into Cu supplementation to promote muscle growth in fish, and help improve the overall productivity of aquaculture.

Prediction model for biochar energy potential based on biomass properties and pyrolysis conditions derived from rough set machine learning.

Biochar is a high-carbon-content organic compound that has potential applications in the field of energy storage and conversion. It can be produced from a variety of biomass feedstocks such as plant-based, animal-based, and municipal waste at different pyrolysis conditions. However, it is difficult to produce biochar on a large scale if the relationship between the type of biomass, operating conditions, and biochar properties is not understood well. Hence, the use of machine learning-based data analysis is necessary to find the relationship between biochar production parameters and feedstock properties with biochar energy properties. In this work, a rough set-based machine learning (RSML) approach has been applied to generate decision rules and classify biochar properties. The conditional attributes were biomass properties (volatile matter, fixed carbon, ash content, carbon, hydrogen, nitrogen, and oxygen) and pyrolysis conditions (operating temperature, heating rate residence time), while the decision attributes considered were yield, carbon content, and higher heating values. The rules generated were tested against a set of validation data and evaluated for their scientific coherency. Based on the decision rules generated, biomass with ash content of 11-14 wt%, volatile matter of 60-62 wt% and carbon content of 42-45.3 wt% can generate biochar with promising yield, carbon content and higher heating value via a pyrolysis process at an operating temperature of 425°C-475°C. This work provided the optimal biomass feedstock properties and pyrolysis conditions for biochar production with high mass and energy yield.

The hydroxy-analogue of selenomethionine alleviated lipopolysaccharide-induced inflammatory responses is associated with recover expression of several selenoprotein encoding genes in the spleens of Kunming mice.

This study aimed to determine whether hydroxy-analogue of selenomethionine (HMSeBA) supplementation could alleviate LPS-induced immunological stress in mice. A total of 90 Kunming mice were randomly assigned into 5 groups. The CON-LPS and CON+LPS groups were fed basal diet (BD), the others were fed BD with different levels of HMSeBA (0.15, 0.30 and 0.45 mg Se per kg) for 4 weeks. Mice were injected with LPS (3 mg per kg BW) or the corresponding physiological saline at 14 d and 28 d. Plasma and spleens were collected at 28 d. The results showed that: (1) LPS injection decreased ADG of mice at the 3rd week, and increased the concentration of IL-6 and TNF-α in plasma and the spleen index; (2) LPS injection induced immunological stress, up-regulated 8 inflammation-related genes and 3 selenoprotein encoding genes, and down-regulated 16 selenoprotein encoding genes in spleens; (3) compared with the CON+LPS group, HMSeBA supplementation increased ADG of mice at 3 weeks and GSH-Px activity in plasma and spleens, decreased spleen index and plasma IL-6 and TNF-α levels, down-regulated mRNA levels of COX-2, ICAM-1, TNF-α, IL-6, and MCP-1, and up-regulated IL-10 and iNOS in spleens. 0.30 mg Se per kg of HMSeBA exhibited the optimal protective effect; (4) HMSeBA supplementation modestly recovered the expression of 8 selenoprotein encoding genes in the spleens of the stressed mice. The results indicated that HMSeBA supplementation alleviated LPS-induced immunological stress accompanied up-regulation of a subset of selenoprotein encoding genes in spleens of mice.

Protective Effect of Selenoprotein X Against Oxidative Stress-Induced Cell Apoptosis in Human Hepatocyte (LO2) Cells via the p38 Pathway.

Oxidative stress, as mediated by ROS (reactive oxygen species), is a significant factor in initiating the cells damaged by affecting cellular macromolecules and impairing their biological functions; SelX, a selenoprotein also known as MsrB1 belonging to the methionine sulfoxide reductase (Msr) family, is the redox repairing enzyme and involved in redox-related functions. In order to more precisely analyze the relationship between oxidative stress, cell oxidative damage, and SelX, we stably overexpressed porcine Selx full-length cDNA in human normal hepatocyte (LO2) cells. Cell viability, cell apoptosis rate, intracellular ROS, and the expression levels of mRNA or protein of apoptosis-related genes under H2O2-induced oxidative stress were detected. We found that overexpression of SelX can prevent the oxidative damage caused by H2O2 and propose that the main mechanism underlying the protective effects of SelX is the inhibition of LO2 cell apoptosis. The results revealed that overexpressed SelX reduced the H2O2-induced intracellular ROS generation, inhibited the H2O2-induced upregulation of Bax and downregulation of Bcl-2, and increased the mRNA and protein ratio of Bcl-2/Bax. Furthermore, it inhibited H2O2-induced p38 MAPK phosphorylation. Taken together, our findings suggested that SelX played important roles in protecting LO2 cells against oxidative damage and that its protective effect is partly via the p38 pathway by acting as a ROS scavenger.

Expression of Selenoprotein Genes Is Affected by Obesity of Pigs Fed a High-Fat Diet.

BACKGROUND: Relations of the 25 mammalian selenoprotein genes with obesity and the associated inflammation remain unclear. OBJECTIVE: This study explored impacts of high-fat diet-induced obesity on inflammation and expressions of selenoprotein and obesity-related genes in 10 tissues of pigs. METHODS: Plasma and 10 tissues were collected from pigs (n = 10) fed a corn-soy-based control diet or that diet containing 3-7% lard from weanling to finishing (180 d). Plasma concentrations (n = 8) of cytokines and thyroid hormones and tissue mRNA abundance (n = 4) of 25 selenoprotein genes and 16 obesity-related genes were compared between the pigs fed the control and high-fat diets. Stepwise regression was applied to analyze correlations among all these measures, including the previously reported body physical and plasma biochemical variables. RESULTS: The high-fat diet elevated (P < 0.05) plasma concentrations of tumor necrosis factor α, interleukin-6, leptin, and leptin receptor by 29-42% and affected (P < 0.05-0.1) tissue mRNA levels of the selenoprotein and obesity-related genes in 3 patterns. Specifically, the high-fat diet up-regulated 12 selenoprotein genes in 6 tissues, down-regulated 13 selenoprotein genes in 7 tissues, and exerted no effect on 5 genes in any tissue. Body weights and plasma triglyceride concentrations of pigs showed the strongest regressions to tissue mRNA abundances of selenoprotein and obesity-related genes. Among the selenoprotein genes, selenoprotein V and I were ranked as the strongest independent variables for the regression of phenotypic and plasma measures. Meanwhile, agouti signaling protein, adiponectin, and resistin genes represented the strongest independent variables of the obesity-related genes for the regression of tissue selenoprotein mRNA. CONCLUSIONS: The high-fat diet induced inflammation in pigs and affected their gene expression of selenoproteins associated with thioredoxin and oxidoreductase systems, local tissue thyroid hormone activity, endoplasmic reticulum protein degradation, and phosphorylation of lipids. This porcine model may be used to study interactive mechanisms between excess fat intake and selenoprotein function.

A high-selenium diet induces insulin resistance in gestating rats and their offspring.

Although supranutrition of selenium (Se) is considered a promising anti-cancer strategy, recent human studies have shown an intriguing association between high body Se status and diabetic risk. This study was done to determine if a prolonged high intake of dietary Se actually induced gestational diabetes in rat dams and insulin resistance in their offspring. Forty-five 67-day-old female Wistar rats (n=15/diet) were fed a Se-deficient (0.01 mg/kg) corn-soy basal diet (BD) or BD+Se (as Se-yeast) at 0.3 or 3.0mg/kg from 5 weeks before breeding to day 14 postpartum. Offspring (n=8/diet) of the 0.3 and 3.0mg Se/kg dams were fed with the same respective diet until age 112 days. Compared with the 0.3mg Se/kg diet, the 3.0mg/kg diet induced hyperinsulinemia (P<0.01), insulin resistance (P<0.01), and glucose intolerance (P<0.01) in the dams at late gestation and/or day 14 postpartum and in the offspring at age 112 days. These impairments concurred with decreased (P<0.05) mRNA and/or protein levels of six insulin signal proteins in liver and muscle of dams and/or pups. Dietary Se produced dose-dependent increases in Gpx1 mRNA or GPX1 activity in pancreas, liver, and erythrocytes of dams. The 3.0mg Se/kg diet decreased Selh (P<0.01), Sepp1 (P=0.06), and Sepw1 (P<0.01), but increased Sels (P<0.05) mRNA levels in the liver of the offspring, compared with the 0.3mg Se/kg diet. In conclusion, supranutrition of Se as a Se-enriched yeast in rats induced gestational diabetes and insulin resistance. Expression of six selenoprotein genes, in particular Gpx1, was linked to this metabolic disorder.

[Study on isozymes in six species of Curcuma].

OBJECTIVE: To explore genetic relationships of the 39 materials in six species of Curcuma. METHOD: The peroxidase isozyme (POD) and esterase isozyme (EST) were studied using vertical slab polyacrylamide gel electrophoresis (PAGE) technique, and the zymograms were analyzed using the software of NTSYSpc2. 1. RESULT: The interspecific zymogramatic differences were obvious. Each species possessed its own specific zymogram distinguishing form the others. In the analysis of EST isozyme, C. phaeocaulis, C. wenyujin, C. kwangsiensis and C. chuanhuangjiang had their own specific zymogram. In the analysis of POD isozyme, just C. phaeocaulis and C. kwangsiensis had their specific zymogram. CONCLUSION: The genetic relationships are not associated with the geographical distributions and the genetic relationship between C. longa and C. sichuanensis are very close.