Glutathione Reductase Gene Research Articles

Uric acid effects on glutathione metabolism estimated by induction of glutamate-cysteine ligase, glutathione reductase and glutathione synthetase in mouse J744A.1 macrophage cell line.

Elevated plasma levels of uric acid (UA) are considered an independent risk factor for hypertension, diabetes, cardiovascular disease, endothelial and vascular damage, obesity, and metabolic syndrome. Even physiological concentrations of soluble UA have been proved to induce gene expression of macrophage-secreted inflammatory cytokines and stimulate production of reactive oxygen species in mature adipocytes. UA is also described as a powerful endogenous plasma antioxidant, which reveals a paradox of duality for this parameter.

Thermal preconditioning in a reef-building coral alleviates oxidative damage through a BI-1-mediated antioxidant response

Global coral reef decline is largely driven by the breakdown of the coral-algal symbiosis during temperature stress. Corals can acclimatize to higher temperatures, but the cellular processes underlying this ability are poorly understood. We show that preconditioning-based improvements in thermal tolerance in Pocillopora acuta are accompanied by increases in host glutathione reductase (GR) activity and gene expression, which prevents DNA damage. A strong correlation between GR and BI-1 expressions in heat-stressed preconditioned corals and the presence of an antioxidant response element (ARE) in the GR promoter suggest BI-1 could regulate GR expression through Nrf2/ARE pathway. To fortify this link, we developed and GFP-validated an siRNA-mediated gene knockdown protocol and targeted the coral BI-1 gene. BI-1 knock-down specifically decreased GR expression and activity and increased oxidative DNA damage in heat-stressed preconditioned corals, showing that a BI-1-mediated, enhanced antioxidant response during acute heat stress is a key mechanism that prevents oxidative DNA damage after preconditioning.

Genome-Wide Analysis and Expression Profiling of Glutathione Reductase Gene Family in Oat (Avena sativa) Indicate Their Responses to Abiotic Stress during Seed Imbibition

Abiotic stress disturbs plant cellular redox homeostasis, inhibiting seed germination and plant growth. This is a crucial limitation to crop yield. Glutathione reductase (GR) is an important component of the ascorbate-glutathione (AsA-GSH) cycle which is involved in multiple plant metabolic processes. In the present study, GRs in A. sativa (AsGRs) were selected to explore their molecular characterization, phylogenetic relationship, and RNA expression changes during seed imbibition under abiotic stress. Seven AsGR genes were identified and mapped on six chromosomes of A, C, and D subgenomes. Phylogenetic analysis and subcellular localization of AsGR proteins divided them into two sub-families, AsGR1 and AsGR2, which were predicted to be mainly located in cytoplasm, mitochondrion, and chloroplast. Cis-elements relevant to stress and hormone responses are distributed in promoter regions of AsGRs. Tissue-specific expression profiling showed that AsGR1 genes were highly expressed in roots, leaves, and seeds, while AsGR2 genes were highly expressed in leaves and seeds. Both AsGR1 and AsGR2 genes showed a decreasing-increasing expression trend during seed germination under non-stress conditions. In addition, their responses to drought, salt, cold, copper, H2O2, and ageing treatments were quite different during seed imbibition. Among the seven AsGR genes, AsGR1-A, AsGR1-C, AsGR2-A, and AsGR2-D responded more significantly, especially under drought, ageing, and H2O2 stress. This study has laid the ground for the functional characterization of GR and the improvement of oat stress tolerance and seed vigor.

Effect of long-term manganese exposure on oxidative stress, liver damage and apoptosis in grouper Epinephelus moara ♀ × Epinephelus lanceolatus ♂

Manganese is an indispensable trace element, however, it may be present at high concentrations in water and sediments of aquatic ecosystems due to natural and anthropogenic activities, and can interfere with physiological and biochemical mechanisms in fish. This study was conducted to determine the toxic effects associated with exposure to Mn2+ (0, 0.5, 1, 2, and 4 mg/L) for 30 d, regarding liver damage and apoptosis in Yunlong grouper (Epinephelus moara♀×E. lanceolatus♂). Expression of superoxide dismutase (sod) and catalase (cat) genes in the liver was significantly increased on days 10 and 20 following Mn2+ exposure (4 mg/L), but was reduced on day 30. Similarly, expression of glutathione peroxidase (gpx) and glutathione reductase (gr) genes was elevated after 10 d of exposure to 2 and 4 mg/L Mn2+, but decreased after 20 and 30 d. After 30 d of exposure to high concentrations (2 and 4 mg/L) of Mn2+, liver tissue showed hepatic sinusoidal gap congestion, dilatation, cell vacuolation, and necrosis. In addition, the activities of alanine aminotransferase (ALT) and aspartate transaminase (AST) as well as 8-hydroxydeoxyguanosine (8-OHdG) levels were significantly increased after Mn2+ exposure. Moreover, Mn2+ exposure altered the expression pattern of some pivotal genes associated to apoptosis (p53, bax, bcl-2, apaf-1, caspase-9, and caspase-3), which suggested that Mn2+ exposure induces apoptosis through the mitochondrial pathway. The above results showed that excessive Mn2+ induced apoptosis and liver damage in grouper through elicitation of oxidative stress. These insights help elucidate the mechanism by which Mn2+ induces toxicity in marine fish, and provide a new perspective regarding the detrimental effects of heavy metals in fish.

Caffeic acid regulated respiration, ethylene and reactive oxygen species metabolism to suppress senescence of Malus domestica

The current study assessed the variations of reactive oxygen species (ROS), respiration and ethylene metabolism in ‘Qiujin’ apples after caffeic acid dipping. Results demonstrated that caffeic acid remarkably inhibited respiratory rate, ethylene release rate and hydrogen peroxide accumulation, but increased reduced glutathione and ascorbic acid contents in apples. Caffeic acid also improved catalase, peroxidase, superoxide dismutase, nicotinamide adenine dinucleotide phosphate oxidase, dehydroascorbate reductase, monodehydroascorbate reductase, glutathione reductase and ascorbate peroxidase activities and gene expressions in apples. In addition, caffeic acid up-regulated MdG6PDH6 and MdAOX expressions, down-regulated MdACS1, MdACO2, MdPK, MdHK3, MdPFK, MdSDH and MdCCO expressions in the fruit. Taken together, caffeic acid could regulate the key enzymes activities and gene expressions in respiration, ethylene and ROS metabolism to suppress senescence of apples after harvest.

Investigation of proteins' interaction network and the expression pattern of genes involved in the ABA biogenesis and antioxidant system under methanol spray in drought-stressed rapeseed.

Drought is one of the most critical abiotic stresses, which significantly impair rapeseed (Brassica napus L.) productivity. Several factors can regulate the stress response, including changes in gene expression in biological pathways, extensive protein interaction networks, and post-translational regulatory factors like microRNAs. External factors can also affect the intensity of the stress response. Therefore, this study investigated protein-protein interactions of some essential genes involved in abscisic acid (ABA) production, antioxidant system, and Krebs cycle. The expression of phyton synthase (PSY), 9-cis-epoxycarotenoid dioxygenase (NCED3), aldehyde oxidase (AAO3), thioredoxin reductase (NTRC), and glutathione reductase (GR) genes in two rapeseed genotypes, i.e., Hyola308 (drought-sensitive) and SLM046 (drought-tolerant) were evaluated using qRT-PCR technique under 72h of drought stress and methanol foliar application. In the SLM046 (tolerant) genotype, the expression levels of PYS, NCED, AAO3, and GR genes were increased after 8h of foliar application. The expression level of the NTR gene was increased 8 and 24h after stress and methanol treatment. In the Hyola308 genotype, PYS, AAO3, NTR, and GR genes' expression level was increased 8h after methanol foliar application, and the NCED gene was increased 24h after stress with methanol treatment. In general, methanol foliar application increased the expression levels of several genes. Particularly, the gene expression was considerably higher in the SLM046 genotype than in Hyola308. Bioinformatics prediction of microRNAs targeting PSY, NCED, GR, NTRC, and AAO3 genes was performed, and 38, 38, 13, 11, and 11 microRNAs were predicted for these genes, respectively. The study of effective microRNAs showed that sometimes more than one type of microRNA could affect the desired gene, and in some cases, a conserved family of microRNAs caused the main effect on gene expression. Overall, our results lay the foundation for functional characterization of these genes or gene-miRNA modules in regulating drought stress tolerance in rapeseed.

Effect of graphene oxide-glyphosate nanocomposite on wheat and rape seedlings: Growth, photosynthesis performance, and oxidative stress response

Recently, nanomaterials have been increasingly applied to improve the bioactivity of pesticides for plant protection. However, the incorporation of nanomaterials into nano-herbicides is still in the early stage of development. In this study, the effect of GO–GLY nanocomposites was tested on wheat and edible rape seedlings in terms of growth parameters, photosynthises, the activity and gene expression of antioxidant enzymes. The results showed that compared with GO or GLY alone, GO–GLY nanocomposite more significantly inhibited the growth of wheat and rape seedlings, decreased the net photosynthetic rate, stomatal conductance, transpiration rate, primary maximum photochemical efficiency of photosystem II, actual quantum yield and photosynthetic electron transport rate, while significantly increased the intercellular CO 2 concentration. These changes may be related to increases in oxidative stress, as indicated by the higher accumulation of O 2 .− and H 2 O 2 under GO–GLY treatment. Furthermore, GO–GLY treatment increased the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) in both plant species compared with GO or GLY alone. In addition, gene expression analysis revealed that GO–GLY treatment upregulated the transcription of CAT s, APXs , MDHAR, and DHAR genes in wheat seedlings, and elevated that of CATs , APXs , MDHAR , DHAR, and GR genes in rape seedlings compared with GO or GLY alone. Ultimately, in response to GO–GLY stress, a preliminary regulatory mechanism was proposed for the self-protective mechanism of wheat and rape seedlings, which lays a theoretical foundation for the wide application of nano-herbicides. • GO can be used as a synergist for heibicide. • The synergistic effect of GLY and GO reduces the use concentration of herbicides. • Antioxidant enzyme related genes play an important role in the detoxification of GO–GLY nanocomposite.

From Photocatalysis to Photo-Electrocatalysis: An Innovative Water Remediation System for Sustainable Fish Farming

In this study, the effects of photo-electrocatalysis (PEC) were evaluated as an innovative application of conventional photocatalysis (PC) to remediate water in a recirculating system for rainbow trout (Oncorhynchus mykiss) culture, in relation to fish welfare and health, with a multidisciplinary approach. Three tanks were employed, equipped with conventional biological filters as a control system, and three tanks equipped with the PEC purification system. The concentrations of ammonia, nitrite and nitrate ions in water were monitored, and the fish’s oxidative damage and stress response were evaluated in parallel. The water of the PEC-treated experimental group showed lower ammonia (TAN) and nitrite concentrations and higher nitrate concentration, possibly deriving from TAN oxidation through PEC, also leading to gaseous N2. Histological analysis did not reveal any pathological alteration in the gills and liver of both groups. The superoxide dismutase (sod1), glutathione reductase (GR), glutathione peroxidase (GPx1), and Tumor necrosis factor (TNFα) gene expressions were significantly higher in the control group than in the PEC-treated group, while the Heat shock protein 70 (Hsp70) expression did not show any difference in the two groups. These results indicate that the use of PEC filters has a positive effect on water quality, compared to the use of conventional biological filters, inducing a high level of welfare in O. mykiss.

Assessing the effects of nickel on, e.g., Medicago sativa L. nodules using multidisciplinary approach.

Industrial wastes and fertilizers can introduce excessive levels of nickel (Ni) into the environment, potentially causing threats to plants, animals, as well as human beings. However, the number of studies on the effects of Ni toxicity on nodules is fairly limited. To address this issue, the effects of increasing Ni concentration on alfalfa nodules were assessed at chemical, biochemical, and transcriptomic levels. For this purpose, plants were grown in soils supplied with Ni (control, 0 mg/kg; C1, 50 mg/kg; C2, 150 mg/kg; C3, 250 mg/kg; and C4, 500 mg/kg) for 90 days. Ni loads in leaves, roots, and nodules were monitored after the exposure period. A set of biochemical biomarkers of oxidative stress was determined in nodules including antioxidants and metal homeostasis as well as lipid peroxidation. Gene expression levels of the main targets involved in oxidative stress and metal homeostasis were assessed. Our data indicated a high concentration of Ni in leaves, roots, and nodules where values reached 25.64 ± 3.04 mg/kg, 83.23 ± 5.16 mg/kg, and 125.71 ± 4.53 mg/kg in dry weight, respectively. Moreover, a significant increase in nodule biomass was observed in plants exposed to C4 in comparison to control treatment and percentage increased by 63%. Then, lipid peroxidation increased with a rate of 95% in nodules exposed to C4. Enzymatic activities were enhanced remarkably, suggesting the occurrence of oxidative stress, with increased superoxide dismutase (SOD), glutathione reductase (GR), and ascorbate peroxidase (APX). Our results showed also a significant upregulation of SOD, GR and APX genes in nodules. Nodule homoglutathione (HGSH) levels increased with the different Ni concentrations, with a remarkable decrease of glutathione S-transferase (GST) activity and glutathione (GSH) content for the highest Ni concentration with 43% and 52% reduction, respectively. The phytochelatin (PC) and metallothionein (MT) concentrations increased in nodules, which implied the triggering of a cellular protection mechanism for coping with Ni toxicity. The results suggested that Ni promotes a drastic oxidative stress in alfalfa nodules, yet the expression of MT and PC to reduce Ni toxicity could be used as Ni stress bioindicators. Our findings provide new insights into the central role of alfalfa nodules in limiting the harmful effects of soil pollution. Therefore, nodules co-expressing antioxidant enzymes may have high phytoremediation potential.

Cornelian cherry (Cornus mas L.) fruit extract improves growth performance, disease resistance, and serum immune-and antioxidant-related gene expression of common carp (Cyprinus carpio)

This study evaluated the use of cornelian cherry (Cornus mas L.) fruit extract on the growth performance, immune responses, and disease resistance in common carp (Cyprinus carpio). A total of 192 fish (initial body weight of 18.34 ± 1.8 g) were randomly distributed in 12 tanks with 16 fish per tank (4 treatments with 3 replications) and fed with diets containing cornelian cherry extract (CCE11CCE (cornelian cherry extract)) at the rate of 0, 0.25, 0.5 and 1%. The final weight of common carp fed CCE at 0.5% was significantly higher than fish fed 0 and 0.25% doses (p < 0.05). In addition, weight gain and specific growth rate were increased, and feed conversion ratio decreased in fish-fed diets containing 0.5 and 1% CCE compared to other groups. The challenge test with A. hydrophila revealed that common carp-fed CCE had a lower mortality rate than the control. The lysozyme activity was markedly higher in common carp fed 0.5% of cornelian cherry extract than in control. The total immunoglobulin and total protein showed higher values in fish fed 0.5 and 1% than the control. The catalase gene showed higher mRNA levels in fish fed 0.5 and 1% than the control. Glutathione reductase gene expression was markedly upregulated in common carp fed 1% of CCE than the control and 0.25% groups. The glutathione S-transferase gene showed higher mRNA levels in fish fed 0.5 and 1% than the control and 0.25% groups. The superoxide dismutase gene expression was markedly higher in common carp fed 0.5% of CCE than in control. The CC-chemokine and interleukin-10 showed higher mRNA levels in fish fed 0.5% than the remaining groups. Hypoxia-inducible factor 1-alpha gene expression was markedly upregulated in common carp fed 1% of CCE than the control and 0.25% groups. The heat shock 70 kDa protein and interleukin-1 beta genes showed higher mRNA levels in fish fed 0.25, 0.5, and 1% than the control. In conclusion, the supplementation of CCE at 0.5–1% is recommended to enhance the growth performance and relieve the impacts of A. hydrophila infection in common carp.

Effect ofmelatonin onthe gastric antioxidant defence inexperimental burn trauma.

Severe burn trauma triggers oxidative gastric mucosal injury. The purpose ofthis study was toinvestigate the antioxidant defence mechanisms and protective effect ofmelatonin inthe gastric mucosa after burn injury. Inorder toinvestigate the mechanisms involved inthe gastric antioxidant defence inarat burn model, quantitative real-time PCR and immunohistochemistry techniques were applied. Ananalysis ofglutathione peroxidase4 (GPx4), glutathione reductase (GR), and catalase (Cat) gene expression was performed along with the evaluation ofthe gastric Cu/Zn superoxide dismutase (Cu/Zn SOD) activity. Melatonin was applied immediately and 12h after 30% oftotal body surface area burns. The burn injury significantly increased the Gpx4 mRNA (P<0.0001) and Gsr mRNA (P<0.0001) expression. Italso had aslight positive effect onthe Cat mRNA expression and Cu/Zn SOD activity. Melatonin, inturn, markedly augmented the burn-induced Cu/Zn SOD (P<0.0001) activity, reversed the Gpx4 mRNA (P<0.0001) and Gsr mRNA (P<0.0001) expression, and inhibited the Cat mRNA level. Inconclusion, the present study suggests that aburn injury adaptively increases the Cu/Zn SOD activity and enhances the Gpx4 and Gsr gene expression inthe gastric mucosa. Melatonin effectively modulates the expression ofthe cellular antioxidant enzymes, and improves the antioxidant defence byaugmenting the Cu/Zn SOD activity.

Polymorphic variants of glutathione reductase - new genetic markers of predisposition to type 2 diabetes mellitus

To study the associations of three common single nucleotide variants of the gene encoding antioxidant system enzyme, glutathione reductase GSR with a predisposition to type 2 diabetes (T2D). The observational mono-center transverse controlled study involved 1032 type 2 diabetics (640 women, 392 men; mean age 61.14.8 years) and 1056 healthy volunteers (676 women, 380 men; mean age 60.96.2 years). Eating habits were evaluated retrospectively according to questionnaire data. A 10 ml blood sample was drawn from all participants in the study for genetic and biochemical tests. Genotyping was done with the use of the iPLEX technology on MassArray System. We first identified the relationship of the polymorphisms rs2551715, rs2911678, rs3757918 of the GSR gene with a reduced risk of developing T2D in the Russian population. At the same time, the protective effects of the variants of the glutathione reductase gene manifested only in individuals with normal body weight provided they consumed fresh vegetables and fruits, whereas in those with insufficient consumption of plant foods, as well as in all overweight and obese patients, the protective effect of GSR was not observed. In patients with T2D, the plasma levels of hydrogen peroxide and the glutathione dimer were sharply increased compared with the controls. We also found that the rs2551715 polymorphism was associated with a lower concentration of hydrogen peroxide in the blood plasma of patients with T2D, while SNP rs2911678 was associated with a decrease in the concentration of the oxidized form of glutathione. Bioinformatical analysis confirmed the positive effect of alternative alleles on GSR expression and revealed the closest protein partners of the enzyme and their joint participation in the metabolism of acetyl-CoA, the catabolism of hydrogen peroxide and the control of cellular redox homeostasis. Polymorphic variants of the GSR gene rs2551715, rs2911678, rs3757918 are associated with a predisposition to T2D, but their relationship with the disease is modulated by the consumption of fresh vegetables and fruits and depends on body mass index.

Understanding role of Glutathione Reductase gene family in drought and heat stresses in Brassica juncea and B. rapa

In the era of global environmental changes, high curiosity in identifying and characterizing new antioxidant enzymes in plants has been witnessed. Previous studies reported the pivotal role played by Glutathione reductase (GR) in maintaining the reduced glutathione pool during stress. However, the knowledge of GR family members and their evolutionary and functional characteristics in oilseed species is limited. In this study, 6 and 4 GRs were identified from Brassica juncea and B. rapa genomes, respectively. Phylogenetic analysis of protein sequences showed diversification of this gene family into cytosolic and chloroplastic GR. Duplication of a single ancestral gene might have led to the diversification of cytosolic and chloroplastic GR before the divergence of monocot and dicot. The cytosolic GRs consisted of complex gene architecture compared to the chloroplastic ones, which can increase their expression level. Chloroplastic GRs showed the presence of N-terminal signal peptide. A high degree of conservation in gene and protein structures in the same sub-cellular compartment was observed. Notably, all cytosolic GRs were found to be differentially expressed under heat and drought stresses. Predicted cis-regulatory elements and miRNA targets were found to be associated with abiotic, biotic and developmental responses. Our study explained the structural and functional information of the GR family and the roles of different members in maintaining redox homeostasis under abiotic stresses. The study has laid the basic ground work for detailed functional characterization in future studies and developing improved oilseed varieties better adaptive to environmental stress conditions.

Exploration of glutathione reductase for abiotic stress response in bread wheat (Triticum aestivum L.)

A total of seven glutathione reductase (GR) genes were identified in Triticum aestivum, which were used for comparative structural characterization, phylogenetic analysis and expression profiling with the GR genes of other cereal plants. The modulated gene expression and enzyme activity revealed the role of GRs in abiotic stress response in T. aestivum. Glutathione reductase (GR) is an enzymatic antioxidant that converts oxidized glutathione (GSSG) into reduced glutathione (GSH) through the ascorbate-glutathione cycle. In this study, a total of seven GR genes forming two homeologous groups were identified in the allohexaploid genome of bread wheat (Triticum aestivum). Besides, we identified three GR genes in each Aegilops tauschii, Brachypodium distachyon, Triticum urartu and Sorghum bicolor, which were used for comparative characterization. Phylogenetic analysis revealed the clustering of GR proteins into two groups; class I and class II, which were predicted to be localized in cytoplasm and chloroplast, respectively. The exon-intron and conserved motif patterns were almost conserved in each group, in which a maximum of 10 and 17 exons were present in chloroplastic and cytoplasmic GRs, respectively. The protein structure analysis confirmed the occurrence of conserved pyridine nucleotide disulfide oxidoreductase (Pyr_redox) and pyridine nucleotide disulfide oxidoreductase dimerization (Pyr_redox_dim) domains in each GR. The active site of GR proteins consisted of two conserved cysteine residues separated by four amino acid residues. Promoter analysis revealed the occurrence of growth and stress-related cis-active elements. Tissue-specific expression profiling suggested the involvement of GRs in both vegetative and reproductive tissue development in various plants. The differential expression of TaGR genes and enhanced GR enzyme activity suggested their roles under drought, heat, salt and arsenic stress. Interaction of GRs with other proteins and chemical compounds of the ascorbate-glutathione cycle revealed their coordinated functioning. The current study will provide a foundation for the validation of the precise role of each GR gene in future studies.

Rhizobium leguminosarum Glutathione Peroxidase Is Essential for Oxidative Stress Resistance and Efficient Nodulation.

Glutathione (GSH) plays a key role in regulating the cellular Redox Homeostasis, and appears to be essential for initiation and development of root nodules. Glutathione peroxidase (Gpx) catalyzes the reduction of H2O2 and organic hydroperoxides by oxidation of GSH to oxidized GSH (GSSG), which in turn is reduced by glutathione reductase (GR). However, it has not been determined whether the Rhizobium leguminosarum Gpx or GR is required during symbiotic interactions with pea. To characterize the role of glutathione-dependent enzymes in the symbiotic process, single and double mutants were made in gpxA (encoding glutathione peroxidase) and gshR (encoding glutathione reductase) genes. All the mutations did not affect the rhizobial growth, but they increased the sensitivity of R. leguminosarum strains to H2O2. Mutant in GpxA had no effect on intracellular GSH levels, but can increase the expression of the catalase genes. The gshR mutant can induce the formation of normal nodules, while the gpxA single and double mutants exhibited a nodulation phenotype coupled to more than 50% reduction in the nitrogen fixation capacity, these defects in nodulation were characterized by the formation of ineffective nodules. In addition, the gpxA and gshR double mutant was severely impaired in rhizosphere colonization and competition. Quantitative proteomics using the TMT labeling method was applied to study the differential expression of proteins in bacteroids isolated from pea root nodules. A total of 27 differentially expressed proteins were identified in these root bacteroids including twenty down-regulated and seven up-regulated proteins. By sorting the down-regulated proteins, eight are transporter proteins, seven are dehydrogenase, deoxygenase, oxidase, and hydrolase. Moreover, three down-regulating proteins are directly involved in nodule process.

Exogenous phytosulfokine α (PSKα) application delays senescence and relieves decay in strawberry fruit during cold storage by triggering extracellular ATP signaling and improving ROS scavenging system activity

During postharvest life, strawberry fruit as a perishable commodity exhibiting short shelf life suffers from fungal decay that severely limits its marketability and nutritional value. Herein, we investigated the mechanisms activated by exogenous phytosulfokine α (PSKα) application at 150 nM to delay senescence and relieve decay in strawberry fruit during storage at 4 °C for 18 days. Our results showed higher extracellular adenosine triphosphate (ATP) accumulation arising from lower apyrase 1 (APY1) gene expression in strawberry fruit treated with 150 nM PSKα during storage at 4 °C for 6 days may serve as a signaling molecule to promote NADPH oxidase activity to trigger signaling H2O2 accumulation giving rise to higher SUMO E3 ligase (SIZ1) gene expression during 18 days of storage at 4 °C. Also, higher superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) genes expression and enzymes activity associated with higher methionine sulfoxide reductase (MSR) and peroxiredoxin (Prx) genes expression in strawberry fruit treated with 150 nM PSKα during storage at 4 °C for 18 days may be ascribed to extracellular ATP signaling. As a result, promoting ROS scavenging systems activity by triggering extracellular ATP signaling in strawberry fruit treated with 150 nM PSKα may be responsible for higher maintenance of membrane integrity as shown by lower malondialdehyde (MDA) accumulation during 18 days of storage at 4 °C. Besides, strawberry fruits treated with 150 nM PSKα exhibited lower weight loss, total soluble solids, and chroma value concurrent with higher firmness, titrable acidity, L* value, and hue angle as quality attributes, which indicated delayed fruit senescence. Based on our findings, exogenous PSKα application unveils its potential to be used as a promising signaling biopeptide for senescence delay and decay alleviation in strawberry fruit during its postharvest life.

Indole-3-lactic acid associated with Bifidobacterium-dominated microbiota significantly decreases inflammation in intestinal epithelial cells

BackgroundBifidobacterium longum subsp. infantis (B. infantis) is a commensal bacterium that colonizes the gastrointestinal tract of breast-fed infants. B. infantis can efficiently utilize the abundant supply of oligosaccharides found in human milk (HMO) to help establish residence. We hypothesized that metabolites from B. infantis grown on HMO produce a beneficial effect on the host.ResultsIn a previous study, we demonstrated that B. infantis routinely dominated the fecal microbiota of a breast fed Bangladeshi infant cohort (1). Characterization of the fecal metabolome of binned samples representing high and low B. infantis populations from this cohort revealed higher amounts of the tryptophan metabolite indole-3-lactic acid (ILA) in feces with high levels of B. infantis. Further in vitro analysis confirmed that B. infantis produced significantly greater quantities of the ILA when grown on HMO versus lactose, suggesting a growth substrate relationship to ILA production. The direct effects of ILA were assessed in a macrophage cell line and intestinal epithelial cell lines. ILA (1-10 mM) significantly attenuated lipopolysaccharide (LPS)-induced activation of NF-kB in macrophages. ILA significantly attenuated TNF-α- and LPS-induced increase in the pro-inflammatory cytokine IL-8 in intestinal epithelial cells. ILA increased mRNA expression of the aryl hydrogen receptor (AhR)-target gene CYP1A1 and nuclear factor erythroid 2–related factor 2 (Nrf2)-targeted genes glutathione reductase 2 (GPX2), superoxide dismutase 2 (SOD2), and NAD(P) H dehydrogenase (NQO1). Pretreatment with either the AhR antagonist or Nrf-2 antagonist inhibited the response of ILA on downstream effectors.ConclusionsThese findings suggest that ILA, a predominant metabolite from B. infantis grown on HMO and elevated in infant stool high in B. infantis, and protects gut epithelial cells in culture via activation of the AhR and Nrf2 pathway.

Zingiber officinale Ethanolic Extract Attenuated Reserpine-Induced Depression-Like Condition and Associated Hippocampal Aberrations in Experimental Wistar Rats.

BackgroundRepeated and regimented treatment with reserpine causes depression-like condition characterized by persistent mood disorder, feelings of severe despondency and dejection, thus altering the hippocampal morphology. Our study compared a well-known antidepressant (fluoxetine), with the potential of Zingiber officinale to ameliorate reserpine-induced depression and the associated hippocampal cornu ammonis 1 (CA1) neuronal cell damage.MethodsForty-eight male Wistar rats, weighing 130–160 g, were randomly assigned to 6 groups (n=8), housed in plastic cages under natural light and dark cycles at room temperature with access to feed and water ad libitum. Group-A (control) received distilled water. Group-B and Group-C orally received 400 mg/kg of Zingiber officinale and 10 mg/kg of fluoxetine, respectively, for 7 days, while Group-D intraperitoneally received 0.2 mg/kg of reserpine for 14 days. Group-E and Group-F intraperitoneally received 0.2 mg/kg of reserpine for 14 days followed by 400 mg/kg of Zingiber officinale and 10 mg/kg of fluoxetine respectively for 7 days. All animals were sacrificed by cervical dislocation at the end of experiment, and the brains hippocampi were dissected, excised and processed for various analyses including histology [H&E], histochemistry of GFAP expression by astrocytes and specific gene expressions including p53 gene, glutathione reductase (GSR), glutathione peroxidase and catalase (CAT).ResultsReserpine significantly depleted the expression of P53 and glutathione reductase (GSR) genes while significantly increasing the expression of glutathione peroxidase 1 (GPx-1) gene (P≤0.05). Also, a marked increase in the expression of catalase (CAT) gene was observed. Furthermore, histoarchitecture (photomicrographs) of hippocampus CA1 region showed disruption in the arrangement of pyramidal neurons and alterations in their morphologies when animals were treated with reserpine (Group D). There was also accompanying increased astrocyte densities within the CA1 region following reserpine treatment. These features indicated deleterious effects of reserpine. Both Zingiber officinale and fluoxetine treatments ameliorated these effects.ConclusionThese findings showed structural and molecular alterations associated with reserpine-induced depression. Also, Zingiber officinale was effective to provide ameliorative and protective effects against the neurotoxic effects of reserpine in the hippocampus, making it a potential candidate for treating depression and its associated neurodegenerative diseases.

Exogenous cysteine alleviates mercury stress by promoting antioxidant defence in maize (Zea mays L.) seedlings

Mercury (Hg) is one of the most important environmental pollutants that negatively affects plant growth and development. Cysteine (Cys) plays an important role in plant response to various environmental stress factors. In the present study, the alleviation of Hg stress through exogenous Cys treatment to maize seedlings was evaluated. For this purpose, a hydroponic experiment was set up to investigate the effect of HgCI2 (100 μM) and in combination with Cys (200 μM) on plant growth, total chlorophyll content, reactive oxygen species, antioxidant enzyme activities, and mRNA expression levels of some antioxidant genes in maize seedlings. The results showed that HgCI2 treatment significantly decreased both root and shoot growth and total chlorophyll content, also increased the malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide levels (O2.–) in maize seedlings. After treatment with 200 μM exogenous Cys combined with 100 μM HgCl2, root and shoot growth and total chlorophyll content increased and the concentration of MDA, H2O2, O2 .– in seedlings notably decreased and catalase (CAT), glutathione reductase (GR), superoxide dismutase (SOD), and peroxidase (POD) activities in seedlings increased significantly. In addition, HgCI2 treatment alone or combination with Cys markedly increased the root and leaf Hg content. The higher amounts of Hg accumulated in the roots of the seedlings. Furthermore, qRT-PCR results showed that the mRNA levels of CAT, GR, and SOD genes were up-regulated at HgCI2 + Cys treatment groups compared to the HgCI2 treatment alone. The results of the study indicated that exogenous Cys improved resistance to Hg-stress in maize seedlings by activating antioxidant defence system.

In vivo AAV delivery of glutathione reductase gene attenuates anti-aging gene klotho deficiency-induced kidney damage

ObjectiveKlotho is an aging-suppressor gene which leads to accelerated aging when disrupted. This study was designed to investigate whether glutathione reductase (GR), a critical intracellular antioxidant enzyme, is involved in the pathogenesis of kidney damages associated with accelerated aging in Klotho-haplodeficient (KL+/–) mice. Methods and resultsKlotho-haplodeficient (KL+/–) mice and WT mice were used. We found that Klotho haplodeficiency impaired kidney function as evidenced by significant increases in plasma urea and creatinine and a decrease in urinary creatinine in KL+/– mice. The expression and activity of GR was decreased significantly in renal tubular epithelial cells of KL+/– mice, suggesting that Klotho deficiency downregulated GR. We constructed adeno-associated virus 2 (AAV2) carrying GR full-length cDNA (AAV-GR). Interestingly, in vivo AAV-GR delivery significantly improved Klotho deficiency-induced renal functional impairment and structural remodeling. Furthermore, in vivo expression of GR rescued the downregulation of the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, which subsequently diminished oxidative damages in kidneys, as evidenced by significant decreases in renal 4-HNE expression and urinary 8-isoprostane levels in KL mice. ConclusionThis study provides the first evidence that Klotho deficiency-induced kidney damage may be partly attributed to downregulation of GR expression. In vivo delivery of AAV-GR may be a promising therapeutic approach for aging-related kidney damage.