Search Results (117)

Cassava (Manihot esculenta Crantz) is a nitrogen-efficient crop that can achieve high biomass production on poor soils. However, the mechanisms underlying the response of cassava to nitrogen-deficiency signals and the regulation of nitrogen use efficiency remain unclear. Here, we found that MeCEPD (MeGRXC1) was specifically induced by CEP6 peptides and low nitrate, and showed higher expression in leaves and stems. Overexpression of MeCEPD enhanced cassava’s tolerance to nitrate deficiency by upregulating the expression of MeNRT2.1, MeNRT2.4, and MeRBCS1A, which was manifested as increased root biomass, greater lateral root number, and darker leaf coloration. In contrast, the MeCEPD-edited lines exhibited a statistically significant reduction in root length, plant height, and biomass compared to the wild-type. Additionally, nitrate deficiency accelerated leaf senescence. Furthermore, yeast two-hybrid (Y2H) assay revealed that MeCEPD interacts with the photosynthesis-related MeRBCS1A and lateral root development-related MeLHW, which may regulate nitrogen use efficiency. Unlike its Arabidopsis thaliana homologs AtCEPD1/2 and AtCEPDL2, which interact with AtTGA1/4, MeCEPD does not interact with MeTGA1 yet still upregulates MeNRT2.1 expression. These findings contribute to our understanding of the complex regulatory mechanisms underlying cassava’s adaptation to low-nitrogen conditions and could provide new information for genetic improvement in nitrogen use efficiency in cassava. Full article

Alterations in glutathione and its metabolism contribute to oxidative stress in COPD, but the role of S-glutathionylation (PSSG) and its major regulator glutaredoxin 1 (Grx1) remains unclear. This study investigated the Grx1/PSSG axis in sputum of COPD patients and its associations with lung function and inflammation, as well as Grx1 secretion in mouse models and in cell culture. In patients with an acute exacerbation, PSSG levels were significantly decreased in sputum, while Grx1 protein and total Grx activity were increased compared to stable COPD. No differences were observed between healthy smokers and stable patients. PSSG levels correlated negatively with sputum neutrophils, IL-8 and IL-1β, but positively with lung function parameters, whereas Grx1 showed the opposite pattern. Enhanced Grx1 levels were also detected in bronchoalveolar lavage fluid from mice exposed to cigarette smoke or chronic pulmonary inflammation. Moreover, epithelial cells and macrophages secreted Grx1 in response to pro-inflammatory mediators, and Grx1 modulated expression of MMPs by macrophages in vitro and in vivo. In conclusion, this study identifies the Grx1/PSSG redox axis as a potential important factor in COPD pathogenesis, especially during exacerbations. Further research should examine in more detail the intricate relation of extracellular Grx1 with lung function and inflammation. Full article

Glutathionyl-hemoglobin (HbSSG) reversibly forms under oxidative stress in erythrocytes, where it constitutes the main redox buffer, in a dynamic equilibrium with the thiol (GSH) and disulfide (GSSG) forms of glutathione, that quickly revert to the reduced thiols when oxidative pressure is relieved. Under acute challenge, the “oxidized” GSH pool distributes between GSSG and HbSSG. Recalculation with electrochemical metrics based on redox potentials of the GSSG/GSH and HbSSG/HbSH pairs, plotted in their phase space, improves the understanding of the competing reduction processes. The first process is reduction of the GSSG pool, while, later, HbSSG reduction occurs as a two-step process. HbSSG accumulation in chronic oxidative stress follows an impairment of these steps. In 30 strong smokers, homogeneous levels of HbSSG are in the range of 2.4–11.7% (E_h −120–−95 mV), but the E_h of the GSSG/GSH redox pair is wider (−160–−240 mV), suggesting that HbSSG accumulation does not depend on GSH availability but on enzyme activity impaired by exogenous and endogenous electrophiles. As hinted by HbSSG measurements, one such species is the dehydro-alanine analog of GSH, produced both from butadiene in exposed petrochemical workers and from the drug busulfan in a treated patient. Inactivation of the low-copy recycling enzymes can thus explain the increase of HbSSG. Full article

Oocysts of Toxoplasma gondii exhibit remarkable resistance to environmental stressors and most conventional disinfectants. Despite its ability to infect a wide variety of host species, sexual reproduction and oocyst formation occur exclusively within felid definitive hosts. Despite the epidemiological significance of oocyst-mediated transmission, the molecular mechanisms governing oocyst production and sporulation remain incompletely understood. Glutaredoxin, serving as a central regulator of cellular redox homeostasis and multiple vital cellular processes in cells, is a potential regulator for oocyst sporulation. Here, we investigated the role of TGME49_227100 (glutaredoxin 5, Grx5) in the T. gondii Pru strain-a type II strain capable of oocyst formation, with a particular focus on its functions during oocyst formation and sporulation. We found that Grx5-knockout tachyzoites exhibited no defects in growth or virulence. Neither in vitro nor in vivo tachyzoite-to-bradyzoite differentiation was affected compared to wild-type parasites. Notably, Grx5 deletion significantly reduced oocyst production in cats by approximately 70%. Additionally, the collected oocysts showed a 50% decrease in sporulation rate. These results indicate that Grx5 plays a predominant role within feline host and the external environmental stage of sporulation, which of these is likely to provide a crucial molecular target for developing a transmission-blocking vaccine. Full article

As a class of glutathione-dependent oxidoreductases, glutaredoxins (GRXs) play a central role in maintaining cellular redox homeostasis, thereby influencing diverse biological processes including growth, development, and stress adaptation in plants. This study identified 36 GRX genes in Litsea cubeba through whole-genome analysis. Phylogenetic classification placed them into four subfamilies (CC-, CGFS-, CPYC-type, and a species-specific SS branch), consistent with patterns in model plants like Arabidopsis thaliana and Oryza sativa, indicating evolutionary conservation of GRX core motifs. Genomic analyses including chromosomal location, collinearity, and gene structure revealed family evolution features. Expression profiling showed 11 LcGRX genes were flower-specific, with marked differential expression during stamen (M2) and pistil (F2) degeneration, supporting their roles in sexual dimorphism. Functional assays confirmed that floral highly expressed LcGRX12 directly interacts with TGA transcription factor LcTGA10, similar to its Arabidopsis homolog ROXY1. This study reveals the GRX-TGA module’s role in floral organ development in L. cubeba, offering insights into redox-mediated sex differentiation in Lauraceae and providing candidate genes for molecular breeding. Full article

The antimicrobial resistance crisis necessitates novel therapeutics. Selenium nanoparticles (SeNPs) offer promise, but their precise bactericidal mechanism remains poorly defined. This study aimed to define the antibacterial action of SeNPs synthesized via a green method with ascorbic acid and sodium citrate. The resulting SeNPs were monodisperse (17.8 ± 0.66 nm), crystalline, and highly stable (zeta potential: −69.9 ± 4.3 mV), exhibiting potent bactericidal activity against multidrug-resistant E. coli. To generate a mechanistic hypothesis, we integrated phenotypic analyses with a preliminary, single-replicate proteomic profiling. Recognizing this as an exploratory step, we focused our analysis on proteins with the most substantial changes. This revealed a coherent pattern of a targeted dual assault on core cellular processes. The data indicate that SeNPs simultaneously induce oxidative stress while severely depleting key components of the primary antioxidant glutathione system; key detoxification enzymes—glutathione S-transferase and glutaredoxin 2—were depleted 18- to 19-fold, while the stress protein HchA was reduced by over 63-fold. Concurrently, the patterns point toward a crippling of central energy metabolism; iron–sulfur enzymes in the TCA cycle, including aconitate hydratase (8.1-fold decrease) and succinate dehydrogenase (13.9-fold decrease), were severely suppressed, and oxidative phosphorylation was impaired (e.g., 4.7-fold decrease in NADH dehydrogenase subunit B). We propose that this coordinated disruption creates a lethal feedback loop leading to metabolic paralysis. Consequently, this work provides a detailed and testable mechanistic hypothesis for SeNPs action, positioning them as a candidate for a potent, multi-targeted antimicrobial strategy against drug-resistant pathogens. Full article

Chronic hyperglycemia inflicts serious cellular damage by inducing oxidative stress through the excessive production of free radicals. This oxidative milieu may impair the cellular redox capacity and disrupt the insulin-like growth factor (IGF) system, thereby increasing the risk of cardiovascular complications. This study aimed to investigate plasma levels of components of the IGF system and antioxidant biomarkers in young adults with type 1 diabetes mellitus (T1DM) compared to age-matched healthy controls in Brazil. This study included 129 patients with T1DM (76 female, 53 male; mean age 26.97 ± 0.6 years) and 95 healthy controls (61 female, 34 male; mean age 27.35 ± 0.68 years). Young Brazilian adults with T1DM had significantly lower mean IGF-I and higher mean IGFBP-1 levels compared to healthy controls. The T1DM group showed a more atherogenic profile, characterized by a significantly elevated ApoB/ApoA1 ratio and increased oxidized LDL levels. However, a subset of patients with significantly better glycemic control exhibited serum IGF-I and IGFBP-1 levels within the normal range observed in controls, which may indicate the presence of residual functional beta-cell activity or reflect better glycemic control in this subgroup. Antioxidant components and oxidative stress biomarkers were significantly upregulated in the T1DM group compared to the control group, suggesting a compensatory adaptive response. No significant correlation was observed between biomarkers of oxidative stress and the IGF-system. Full article

Background: Fascioliasis, caused by Fasciola species, is a significant public health concern affecting over 250 million people globally and causing annual economic losses exceeding USD 6 billion. The sole FDA-approved treatment, triclabendazole (TCZ), faces increasing resistance due to extensive use, highlighting the urgent need for alternative therapeutic targets. A promising candidate is thioredoxin glutathione reductase (TGR), a multifunctional enzyme unique to platyhelminths, essential for redox balance and parasite survival. Methods: This study investigated the antioxidant and enzymatic activities of recombinant Fasciola gigantica TGR (FgTGR), its localization within the parasite, and its inhibition by furoxan derivatives. FgTGRsec (FgTGR containing selenocysteine) was expressed and purified, and its enzymatic activities, including thioredoxin reductase (TrxR), glutathione reductase (GR), and glutaredoxin (Grx), were characterized. Results: Immunolocalization studies revealed FgTGR’s presence in critical tissues, underscoring its functional significance. Antioxidant assays demonstrated the protein’s role in protecting against oxidative damage. Inhibition assays with furoxan derivatives identified potential inhibitors targeting TGR activity. Sequence and phylogenetic analyses showed FgTGR’s evolutionary conservation among trematodes, confirming its potential as a drug target. Conclusions: The study’s findings establish FgTGR as a critical enzyme for parasite survival and a promising target for developing novel therapeutics. These results pave the way for the further screening and optimization of TGR inhibitors, offering a strategic approach to overcoming TCZ resistance and improving fascioliasis control. Full article

The glyoxalase pathway intermediate S-d-lactoylglutathione was recently implicated in protein post-translational modifications in animal systems. Here, we examined the spontaneous modification of the Arabidopsis thaliana cytosolic glyceraldehyde-3-phosphate dehydrogenase C1 (GAPC1) by this compound. Incubation of GAPC1 with S-d-lactoylglutathione resulted in the inhibition of enzyme activity. The inhibitory effect was concentration dependent and increased at alkaline pHs. Furthermore, the inhibition of GAPC1 by S-d-lactoylglutathione was favored by oxidative conditions and reversed by reduction with dithiothreitol. Analyses of the S-d-lactoylglutathione-treated protein by nanoLC-MS/MS revealed S-glutathionylation of its two Cys residues and N-lactoylation of six Lys residues. Protein structure predictions showed that the double S-glutathionylation is accommodated by the GAPC1 catalytic pocket, which likely explains enzyme inhibition. N-lactoylated sites overlap partially with previously reported N-acetylated sites at the surface of the GAPC1 tetramer. The efficiency of cytosolic glutaredoxin and thioredoxin isoforms was tested for reversing the S-d-lactoylglutathione-induced modification. In these assays, recovery of GAPC1 activity after inhibition by S-d-lactoylglutathione treatment was used as indicator of efficiency. The results show that both types of redoxins were able to reverse inhibition. We propose a model describing the mechanisms involved in the two types of post-translational modifications found on GAPC1 following exposure to S-d-lactoylglutathione. The possible involvement of these findings for the control over glycolytic metabolism is discussed. Full article

Glutaredoxins (GRXs) are important proteins in plant development and environmental adaptation. Despite extensive characterization of GRX gene family members in various plant species, limited research has been conducted on the identification and functional analysis of GRXs in the economically important Solanaceae family pepper (Capsicum annuum). This study identified 35 typical GRX genes in pepper and categorized them into three distinct groups: CC-, CGFS-, and CPYC-type, based on the phylogenetic topology, which was consistent with motif or domain arrangement, and gene structures. Furthermore, the determination of ω values indicated that purifying selection was a significant factor in the evolutionary diversification of GRX genes in the eudicot family. Intra-genome investigations demonstrated that both segmental and tandem duplications were involved in the expansion of CaGRX genes. Moreover, examination of collinearity within the Solanaceae family revealed 53 orthologous pairs of GRX genes. Additionally, prediction of cis-regulatory elements and analysis of expression profiles revealed the significant involvement of GRX genes in plant stress response, specifically in relation to hypoxia and submergence. Subsequent subcellular localization examination suggested CaGRX may be involved in the endomembrane system and regulation of oxidative balance in plants. Collectively, these findings enhance our comprehension of the structural and functional properties of GRX in pepper, and establish a groundwork for subsequent functional characterization of the CaGRX genes. Full article

The ZC4H2 gene is the site of congenital mutations linked to neurodevelopmental and musculoskeletal pathologies collectively termed ZARD (ZC4H2-Associated Rare Disorders). ZC4H2 consists of a coiled coil and a single novel zinc finger with four cysteines and two histidines, from which the protein obtains its name. Alpha Fold 3 confidently predicts a structure for the zinc finger but also for similarly sized random sequences, providing equivocal information on its folding status. We show using synthetic peptide fragments that the zinc finger of ZC4H2 is genuine and folds upon binding a zinc ion with picomolar affinity. NMR pH titration of histidines and UV–Vis of a cobalt complex of the peptide indicate its four cysteines coordinate zinc, while two histidines do not participate in binding. The experimental NMR structure of the zinc finger has a novel structural motif similar to RANBP2 zinc fingers, in which two orthogonal hairpins each contribute two cysteines to coordinate zinc. Most of the nine ZARD mutations that occur in the ZC4H2 zinc finger are likely to perturb this structure. While the ZC4H2 zinc finger shares the folding motif and cysteine-ligand spacing of the RANBP2 family, it is missing key substrate-binding residues. Unlike the NZF branch of the RANBP2 family, the ZC4H2 zinc finger does not bind ubiquitin. Since the ZC4H2 zinc finger occurs in a single copy, it is also unlikely to bind DNA. Based on sequence homology to the VAB-23 protein, the ZC4H2 zinc finger may bind RNA of a currently undetermined sequence or have alternative functions. Full article

The regulation of oxidative stress is an effective strategy for treating cancers. Therapeutic strategies for modulating an undesirable redox balance against cancers have included the enhancement of oxidative components, reducing the action of antioxidant systems, and the combined application of radiation and redox-modulating drugs. A precise understanding of redox regulation is required to treat different kinds of cancer. This review focuses on the redox regulation and oxidative stress defense systems of lung cancers. Thus, we highlighted several enzymatic antioxidant components, such as superoxide dismutase, catalase, heme oxygenase-1, peroxiredoxin, glutaredoxin, thioredoxin, thioredoxin reductase, glutathione peroxidase, and antioxidant components, including glutathione, nuclear factor erythroid 2–related factor 2, 8-oxo-7,8-dihydro-2′-deoxyguanosine, and mitochondrial citrate carrier SLC25A1, based on PubMed and Scopus-indexed literature. Understanding the oxidative stress defense system in lung cancer would be beneficial for developing and expanding therapeutic strategies, such as drug development, drug design, and advanced delivery platforms. Full article

Background/Objectives: Prenatal hypoxia (PH) is a leading cause of nervous system disorders in early childhood and subsequently leads to a decline in the cognitive and mnemonic functions of the central nervous system (such as memory impairment, reduced learning ability, and information processing). It also increases anxiety and the risk of brain disorders in adulthood. Compensatory–adaptive mechanisms of the mother–placenta–fetus system, which enhance the fetus’s CNS resilience, are known, including the activation of endogenous neuroprotection in response to hypoxic brain injury through the pharmacological modulation of HSP₇₀. Methods: To evaluate the effect of HSP₇₀ modulators—Cerebrocurin, Angiolin, Tamoxifen, Glutaredoxin, Thiotriazoline, and HSF-1 (heat shock factor 1 protein), as well as Mildronate and Mexidol—on the motor skills, exploratory behaviors, psycho-emotional activities, learning, and memories of offspring after PH. Experimental PH was induced by daily intraperitoneal injections of sodium nitrite solution into pregnant female rats from the 16th to the 21st day of pregnancy at a dose of 50 mg/kg. The newborns received intraperitoneal injections of Angiolin (50 mg/kg), Thiotriazoline (50 mg/kg), Mexidol (100 mg/kg), Cerebrocurin (150 µL/kg), L-arginine (200 mg/kg), Glutaredoxin (200 µg/kg), HSF-1 (50 mg/kg), or Mildronate (50 mg/kg) for 30 days. At 1 month, the rats were tested in the open field test, and at 2 months, they were trained and tested for working and spatial memory in the radial maze. Results: Modeling PH led to persistent impairments in exploratory activity, psycho-emotional behavior, and a decrease in the cognitive–mnestic functions of the CNS. It was found that Angiolin and Cerebrocurin had the most pronounced effects on the indicators of exploratory activity and psycho-emotional status in 1-month-old animals after PH. They also exhibited the most significant cognitive-enhancing and memory-supporting effects during the training and evaluation of skill retention in the maze in 2-month-old offspring after PH. Conclusions: for the first time, we obtained experimental data on the effects of HSP₇₀ modulators on exploratory activity, psycho-emotional behavior, and cognitive–mnestic functions of the central nervous system in offspring following intrauterine hypoxia. Based on the results of this study, we identified the pharmacological agents Angiolin and Cerebrocurin as promising neuroprotective agents after perinatal hypoxia. Full article

The oxidative modification of specific cysteine residues to persulfides is thought to be the main way by which hydrogen sulfide (H₂S) exerts its biological and signaling functions. Therefore, protein persulfidation represents an important thiol-switching mechanism as other reversible redox post-translational modifications. Considering their reductase activity but also their connections with proteins that generate H₂S and its related molecules, the glutaredoxin (GRX) and thioredoxin (TRX)-reducing systems have potential dual roles in both protein persulfidation and depersulfidation. In this review, we will first focus on recent advances describing the physiological pathways leading to protein persulfidation before discussing the dual roles of the physiological TRX and glutathione/GRX-reducing systems in protein persulfidation/depersulfidation. Full article

Ochratoxin A (OTA) is a naturally occurring mycotoxin mainly produced by certain species of Aspergillus and Penicillium and is a serious threat to human health and food safety. Previous studies showed that Brevundimonas naejangsanensis ML17 can completely degrade 1 μg/mL of OTA. The aim of this study was to investigate the degradation effect of ML17 at different concentrations of OTA, and specifically, to investigate the mechanism of OTA degradation by ML17. The growth of ML17 was not affected by exposure to 6 μg/mL OTA within 24 h. ML17 could almost completely degrade 12 μg/mL of OTA within 36 h, converting it into the non-toxic OTα and L-phenylalanine. Transcriptomic analysis showed that 275 genes were upregulated, whereas three genes were downregulated in ML17 under the stress of 1 μg/mL OTA. Functional enrichment analysis showed that exposure to OTA enhanced translation, amide and peptide biosynthesis and metabolism, promoted oxidative phosphorylation, and increased ATP production. Further analysis revealed that, when exposed to OTA, ML17 exerted a stress-protective effect by synthesizing large amounts of heat shock proteins, which contributed to the correct folding of proteins. Notably, genes related to antioxidant activity, such as peroxiredoxin, superoxide dismutase, and glutaredoxin 3, were significantly upregulated, indicating that ML17 can resist the toxic effects of OTA through adjusting its metabolic processes, and the enzyme-coding gene0095, having OTA degradation activity, was found to be upregulated. This suggests that ML17 can achieve OTA degradation by regulating its metabolism, upregulating its antioxidant system, and upregulating enzyme-encoding genes with OTA degradation activity. Our work provides a theoretical reference for clarifying the mechanism of OTA degradation by ML17. Full article