Expression Patterns Of Antioxidant Genes Research Articles

The Influence of Water Nitrate Concentration Combined with Elevated Temperature on Rainbow Trout Oncorhynchus mykiss in an Experimental Aquaponic Setup

Intensive recirculating systems are a fast-developing sector of aquaculture. While several warm-water fish have been reared in aquaponics, almost no data are available for cold-water species. The determination of nitrate toxicity thresholds in recirculating aquaculture is crucial. Different pollutants are typically more toxic at elevated temperatures. We investigated the performance of Oncorhynchus mykiss under two different nitrate levels and two temperatures. We applied a 2 × 2 factorial design, where fish (9.78 ± 0.51 g) were exposed to nitrate concentrations of 40 or 110 mg/L NO3− and to temperatures of 17 °C or 21 °C for 20 days. This study focused on understanding the physiological responses of rainbow trout to relatively low nitrate levels under heat stress in order to investigate the feasibility of integrating this species into commercial aquaponics. The growth, condition, and expression of genes involved in metabolism, heat shock, antioxidant, and immune response were assessed in the liver, together with the activities of enzymes related to glucose and fatty acid metabolism. High nitrate levels at 17 °C affected the condition but did not alter growth, leading to increased glycolytic potential and, occasionally, a greater reliance on lipid oxidation. Antioxidant defense was mainly induced due to high nitrates and the similar expression patterns of antioxidant genes observed under high nitrate at both 17 °C and 21 °C. Warm exposure decreased condition and growth, leading to greatly reduced glucokinase transcription, irrespective of the nitrate levels. Exposure to 21 °C and high nitrate led to equivalent growth and condition as well as to a milder inflammatory response combined with metabolic readjustments (enhancement of glycolytic and lipid oxidation pathways) compared to the low nitrates at 21 °C. Based on the results, rearing at a temperature close to 21 °C should be avoided for fingerling growth, while NO3− concentration until 110 mg/L may not have severe impacts on fingerling health and growth at 17 °C. In addition, rainbow trout fingerlings can tolerate a 20-day exposure at 21 °C and NO3− up to 110 mg/L. Additional factors should always be considered, such as specific water quality parameters, for a comprehensive approach to assessing the feasibility of rainbow trout aquaculture in aquaponics.

Sulfate improves cadmium tolerance by limiting cadmium accumulation, modulation of sulfur metabolism and antioxidant defense system in maize

Cadmium (Cd) contamination of agricultural soil has become a serious threat to global food security. The present study highlights the role of added sulfate (SO42−) in modulating sulfur metabolism and antioxidant defense system conferring tolerance against Cd stress in maize. Expression patterns of antioxidant genes, transporters involved in SO42− and Cd accumulation, antioxidant enzyme activity, membrane damage, in vivo reactive oxygen species (ROS) detection and hydrogen peroxide (H2O2) accumulation under Cd stress in presence (T2) or absence (T1) of excess SO42− were studied to get an overview of cellular manoeuvering in conquering Cd induced oxidative stress damages. Moreover, dynamic correlations between miR398a, miR395d, miR408a and their target genes under Cd exposure were validated through qRT-PCR. Supplementation of the ¼ Murashige and Skoog (MS) media with excess sulfate [600 μM (NH4)2SO4] markedly restored the shoot biomass under Cd stress (100 μM CdCl2). Presence of excess SO42− in the nutrient media significantly reduced Cd uptake as well as tissue Cd accumulation in T2 plants. Foliar dark blue and deep brown spots revealed after histochemical staining with nitroblue tetrazolium (NBT) and 3′3′-diaminobenzidine (DAB) respectively indicated severe oxidative burst in T1 plants under Cd treatment. The chloromethyl derivative of 2′, 7′-Dichlorofluorescin diacetate (CM-H2DCFDA) and dihydroethidium (DHE) staining further supported enhanced ROS formation in roots of Cd challenged T1 plants. Enhanced reduced glutathione (GSH) level both in root and above ground part of T2 plants might be responsible for their better performance under Cd stressed condition as evident from non-significant increase in superoxide anion (O2−), low H2O2 and thiobarbituric acid reactive substances (TBARS) levels as compared to T1 plants. Taken together, our findings indicate that fine adaptation of sulfate uptake and assimilation in sulfate supplemented maize plants (T2) might satisfy two contrasting needs: (a) maintaining high GSH pool essential for sustaining balanced redox status under stress condition; (b) alleviating Cd stress effects by means of GSH mediated detoxification pathways.

Expression patterns of antioxidant genes in human SH-SY5Y cells after treatment with methadone

The expression levels of nine antioxidant genes in SH-SY5Y cells exposed to methadone (final concentrations 1–20µM) were investigated. Based on this study the genes could be categorized on three different groups. The number of down-regulated genes were increased as a function of exposure time (P=0.004). The methadone associated mRNA alterations were modulated by N-acetyl-cysteine. These findings suggested that different pathways for regulation of antioxidant genes could be active after exposing of SH-SY5Y cells to methadone; and also suggested that methadone might act by inducing the reactive oxygen species.

Recovery of antioxidant gene expression in sacred lotus (Nelumbo nucifera Gaertn.) embryonic axes enhances tolerance to extreme high temperature

Sacred lotus ( Nelumbo nucifera Gaertn.) seed is long-living and have various stress-resistance characteristics. We investigated the protecting mechanisms of lotus seeds against extreme high temperature by comparison of expression patterns of antioxidant genes in embryonic axes between exposure and non-exposure to extreme high temperature. It was shown that viability of seeds did not severely decline after exposure to 90°C for 24 h. Germination and growth were inhibited and H 2 O 2 was accumulated at high level in the lotus embryonic axes germinated after heat treatment. Transcriptional levels of superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD), glutathione peroxidase (GPX) and thioredoxin-dependent peroxidase (TPX) encoding genes were induced to rise at late germination stage. Transcriptional levels of APX, POD, GPX and alternative oxidase (AOX) encoding genes were also immediately stimulated and up-regulated after heat treatment. These results suggest that the embryonic axes of sacred lotus maintain a protective and recovery mechanism from heat damage during and after exposure to extreme high temperature. Furthermore, the recovery of antioxidant gene expression enhanced tolerance to extreme high-temperature stress in sacred lotus. Keywords: Antioxidant gene, high temperature, seed germination, Nelumbo nucifera Gaertn

Administration with Bushenkangshuai Tang alleviates UV irradiation- and oxidative stress-induced lifespan defects in nematode Caenorhabditis elegans

During normal metabolism, oxidative byproducts will inevitably generate and damage molecules thereby impairing their biological functions, including the aging process. Bushenkangshuai Tang (补肾抗衰方, BT) is a traditional Chinese medicine widely used for clinically treating premature ovarian failure. In the present study, BT administration at high concentrations significantly increased lifespan, slowed aging-related decline, and delayed accumulation of aging-related cellular damage in wild-type Caenorhabditis elegans. BT administration could further largely alleviate the aging defects induced by UV and oxidative stresses, and BT administration at different concentrations could largely rescue the aging defects in mev-1 mutant animals. The protective effects of BT administration on aging process were at least partially dependent on the Ins/IGF-like signaling pathway. Moreover, BT administration at different concentrations obviously altered the expression patterns of antioxidant genes and suppressed the severe stress responses induced by UV and oxidative stresses, suggesting that BT-induced tolerance to UV or oxidative stress might result from reactive oxygen species scavenging. BT administration during development was not necessarily a requirement for UV and oxidative stress resistance, and the concentrations of administrated BT examined were not toxic for nematodes. Therefore, BT administration could effectively retrieve the aging defects induced by UV irradiation and oxidative stress in Caenorhabditis elegans.