Biomineralized ZIF-8 Encapsulating SOD from Hydrogenobacter Thermophilus: Maintaining Activity in the Intestine and Alleviating Intestinal Oxidative Stress.

Oxidative stress is a major factor leading to inflammation and disease occurrence, and superoxide dismutase (SOD) is a crucial antioxidative metalloenzyme capable of alleviating oxidative stress. In this study, a novel thermostable SOD gene is obtained from the Hydrogenobacter thermophilus strain (HtSOD), transformed and efficiently expressed in Escherichia coli with an activity of 3438 U mg-1, exhibiting excellent thermal stability suitable for scalable production. However, the activity of HtSOD is reduced to less than 10% under the acidic environment. To address the acid resistance and gastrointestinal stability issues, a biomimetic mineralization approach is employed to encapsulate HtSOD within the ZIF-8 (HtSOD@ZIF-8). Gastrointestinal simulation results show that HtSOD@ZIF-8 maintained 70% activity in simulated gastric fluid for 2 h, subsequently recovering to 97% activity in simulated intestinal fluid. Cell and in vivo experiments indicated that HtSOD@ZIF-8 exhibited no cytotoxicity and do not impair growth performance. Furthermore, HtSOD@ZIF-8 increased the relative abundance of beneficial microbiota such as Dubosiella and Alistipes, mitigated oxonic stress and intestinal injury by reducing mitochondrial and total reactive oxygen species (ROS) levels in diquat-induced. Together, HtSOD@ZIF-8 maintains and elucidates activity in the intestine and biocompatibility, providing insights into alleviating oxidative stress in hosts and paving the way for scalable production.

Ultra-Small Copper-Based Multienzyme-Like Nanoparticles Protect Against Hepatic Ischemia-Reperfusion Injury Through Scavenging Reactive Oxygen Species in Mice.

Hepatic ischemia-reperfusion injury (IRI) is a severe complication that occurs in the process of liver transplantation, hepatectomy, and other end-stage liver disease surgery, often resulting in the failure of surgery operation and even patient death. Currently, there is no effective way to prevent hepatic IRI clinically. Here, it is reported that the ultra-small copper-based multienzyme-like nanoparticles with catalase-like (CAT-like) and superoxide dismutase-like (SOD-like) catalytic activities significantly scavenge the surge-generated endogenous reactive oxygen species (ROS) and effectively protects hepatic IRI. Density functional theory calculations confirm that the nanoparticles efficiently scavenge ROS through their synergistic effects of the ultra-small copper SOD-like activity and manganese dioxides CAT-like activity. Furthermore, the results show that the biocompatible CMP NPs significantly protected hepatocytes from IRI in vitro and in vivo. Importantly, their therapeutic effect is much stronger than that of N-acetylcysteamine acid (NAC), an FDA-approved antioxidative drug. Finally, it is demonstrated that the protective effects of CMP NPs on hepatic IRI are related to suppressing inflammation and hepatocytic apoptosis and maintaining endothelial functions through scavenging ROS in liver tissues. The study can provide insight into the development of next-generation nanomedicines for scavenging ROS.

Induction of phytoextraction, phytoprotection and growth promotion activities in Lupinus albus under mercury abiotic stress conditions by Peribacillus frigoritolerans subsp., mercuritolerans subsp. nov.

Strain SAICEUPBMT was isolated from soils of Almadén (Ciudad Real, Spain), subjected to a high mercury concentration. SAICEUPBMT significantly increased aerial plant weight, aerial plant length and the development of secondary roots under mercury stress; increased twice the absorption of mercury by the plant, while favoring its development in terms of biomass. Similarly, plants inoculated with SAICEUPBMT and grown in soils contaminated with mercury, express a lower activity of antioxidant enzymes; catalase enzymes (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR) for defense against ROS (reactive oxygen species). Whole genome analysis showed that ANI (95. 96 %), dDDH (72.9 %), AAI (93.3 %) and TETRA (0.99) values were on the thresholds established for differentiation a subspecies. The fatty acids analysis related the strain with the Peribacillus frigoritolerans species. And the synapomorphic analysis reveals a common ancestor with analysis related the strain with the Peribacillus frigoritolerans species. Results from genomic analysis together with differences in phenotypic features and chemotaxonomic analysis support the proposal of strain SAICEUPBMT as the type strain of a novel subspecies for which the name Peribacillus frigoritolerans subps. mercuritolerans sp. nov is proposed. The absence of virulence genes and transmissible resistance mechanisms reveals its safety for agronomic uses, under mercury stress conditions. The ability of Peribacillus frigoritolerans subsp. mercuritolerans subsp. nov to improve plant development was tested in a Lupinus albus model, demonstrating a great potential for plant phytoprotection against mercury stress.

Protective effect and mechanism of lycium barbarum polysaccharide against UVB-induced skin photoaging.

BACKGROUND: Cellular senescence can be categorized into two main types, including exogenous and endogenous aging. Photoaging, which is aging induced by ultraviolet (UV) radiation, significantly contributes to exogenous aging, accounting for approximately 80% of such cases. Superoxide Dismutase (SOD) is a class of antioxidant enzymes, with SOD2 being predominantly localized in the mitochondrial matrix. Ultraviolet radiation (UVR) inhibits SOD2 activity by acetylating the key lysine residues on SOD2. Sirtuin3 (SIRT3), the principal mitochondrial deacetylase, enhances the anti-oxidant capacity of SOD2 by deacetylating. Lycium barbarum polysaccharide (LBP) is the main bioactive component extracted from Lycium barbarum (LB). It has been reported to have numerous potential health benefits, such as anti-oxidation, anti-aging, anti-inflammatory and anti-apoptotic properties. Furthermore, LBP has been shown to regulate hepatic oxidative stress via the SIRT3-SOD2 pathway. The aim of this study was to construct a UVB-Stress-induced Premature Senescence (UVB-SIPS) model to investigate the protective effects and underlying mechanisms of LBP against UVB-induced skin photoaging. METHODS: Irradiated with different UVB doses to select the suitable dose for constructing the UVB-SIPS model. Cell morphology was observed using a microscope. The proportion of senescent cells was assessed by senescence-associated ß-galactosidase (SA-ß-gal) staining. Cell viability was studied using the Cell Counting Kit-8 (CCK-8). Intracellular levels of reactive oxygen species (ROS) were observed using flow cytometry and an inverted fluorescence microscope. Expression of γ-H2AX was investigated using flow cytometry. Western blot (WB) was used to verify the expression of senescence-associated proteins (p21, p53, MMP-1, and MMP-3). Enzyme-Linked Immunosorbnent Assay (ELISA) was used to measure pro-inflammatory cytokines levels (IL-6, TNF-α). WB was also used to analyze the expression of SIRT3, SOD2, and Ac-SOD2, and a specific kit was employed to detect SOD2 activity. RESULTS: Our results suggested that the UVB-SIPS group pre-treated with LBP exhibited a reduced proportion of cells positive for SA-ß-gal staining, mitigated production of intracellular ROS, an amelioration in γ-H2AX expression, and down-regulated expression of senescence-associated proteins and pro-inflammatory cytokines as compared to the UVB-SIPS group. Moreover, in contrast to the control group, the UVB-SIPS group showed regulated SIRT3 expression and SOD activity, elevated Ac-SOD2 expression and an increased ratio of Ac-SOD2/SOD2. However, the UVB-SIPS group pre-treated with LBP showed an upregulation of SIRT3 expression and enhanced SOD activity, a reduction in AC-SOD2 expression, and a decreased ratio of AC-SOD2/SOD2, compared to the untreated UVB-SIPS group. Additionally, the photo-protective effect of LBP was diminished following treatment with 3-TYP, a SIRT3-specific inhibitor. This study suggested that LBP, a natural component, exhibits anti-oxidant and anti-photoaging properties, potentially mediated through the SIRT3-SOD2 pathway.

Effect of sulforaphane on testicular ischemia-reperfusion injury induced by testicular torsion-detorsion in rats.

Testicular ischemia-reperfusion induces enhanced concentration of reactive oxygen species. The increased reactive oxygen species harm cellular lipids, nucleic acids, proteins, and carbohydrates, and ultimately cause testicular injury. Sulforaphane, a kind of natural dietary isothiocyanate, exists predominantly in some cruciferous vegetables, like broccoli and cabbage. It can protect tissues from oxidative stress-induced damage. Herein, we analyzed the effectiveness of sulforaphane in treating ischemia-reperfusion injury occurring after testicular torsion-detorsion. Male rats (n = 60) were grouped as follows: sham-operated group, unilateral testicular ischemia-reperfusion group, and unilateral testicular ischemia-reperfusion group receiving sulforaphane treatment at 5 mg/kg. No testicular torsion-detorsion was performed in the sham group. Unilateral testicular ischemia-reperfusion model was created by detorsion after 2 h of left testicular torsion. In the sulforaphane-treated group, intraperitoneal sulforaphane (5 mg/kg) was administered at left testicular detorsion. Biochemical assay, Western blot, and hematoxylin and eosin staining were used to evaluate testicular malondialdehyde content (an important marker of reactive oxygen species), protein levels of superoxide dismutase and catalase (intracellular antioxidant defense mechanism), and testicular reproductive function, respectively. In testicular tissues, malondialdehyde content was significantly promoted, while protein levels of superoxide dismutase and catalase, and testicular reproductive function were significantly reduced in ipsilateral testes by testicular ischemia-reperfusion. Nevertheless, sulforaphane administration partially reversed the effect of testicular ischemia-reperfusion on these indexes. It can be concluded that sulforaphane elevates protein levels of superoxide dismutase and catalase, and suppresses reactive oxygen species content, thereby preventing ischemia-reperfusion injury in testis.

Arbuscular Mycorrhizal Fungi Ameliorate Selenium Stress and Increase Antioxidant Potential of Zea mays in Seleniferous Soil.

The indigenous arbuscular mycorrhizal fungi (AMF) spores were isolated from rhizosphere soil associated with maize plants grown in natural selenium-impacted agricultural soils present in north-eastern region of Punjab, India (32°46' N, 74°46' N), with selenium concentration ranging from 2.1 to 6.1 mg kg-1 dry weight, and their role in plant growth promotion, mitigation of selenium stress and phytochemical and antioxidant potential of host maize plants in natural seleniferous soil were examined. Soils with selenium content between 2 and 200 mg kg-1 and producing plants with 45 mg selenium kg-1 dry weight are considered seleniferous soils. AMF inoculum consisting of indigenous AMF spores multiplied in pot cultures were inoculated to maize seeds at the time of sowing alongside control maize seeds in a total of 12 plots (6 replicates) made in seleniferous agricultural fields and sampled at maturity, i.e. 3 months. A significant difference was observed in plant growth parameters between control and AMF-inoculated maize plants. AMF-inoculated plants had 24.0 cm and 101.1 cm higher root and shoot length along with 27.2 g, 119.4 g and 28.1 g higher root, shoot and maize cob biomass in comparison to control plants. Se uptake studies through measurement of the emission spectrum of piazselenol complex by fluorescence spectrometry revealed that AMF inoculation led to 6.3 µg g-1 more selenium accumulation in mycorrhizal maize roots in comparison to control roots but lesser translocation to shoots and seeds, i.e. 17.17 µg g-1 and 19.58 µg g-1 lesser. AMF increased total phenolic content by 13 µg GAE mg-1 and total flavonoid content by 13.4 µg QE mg-1 in inoculated maize plants when compared to control plants. Antioxidant studies revealed that AMF inoculation also led to significant rise in enzyme activities by a difference of 115 and 193 EU g-1 in catalase, 140 and 93 EU g-1 in superoxide dismutase, 15 and 37 EU g-1 in ascorbate peroxidase and 19.8 and 23.6% higher DPPH radical scavenging activities, respectively, in shoots and roots of plants with AMF inoculation. The findings of this study imply that AMF inoculated to maize plants in seleniferous field boost their plant growth and phytochemical and antioxidant properties, as well as minimize Se bioaccumulation in shoots and seeds of plants inoculated with AMF in comparison to control plants.

Oxidative damage biomarkers and antioxidant enzymes in saliva of patients with peri-implant diseases.

OBJECTIVES: 8-hydroxydeoxyguanosine (8-OHdG) and Malondialdehyde (MDA) are commonly used as markers to evaluate oxidative DNA and Lipid damage in disorders including chronic inflammatory diseases. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) protect tissues against oxidative injury from free oxygen radicals generated by various metabolic processes. The aim of this study was to evaluate 8-OHdG and MDA levels, and SOD and GPx activities in whole saliva of patients with peri-implant diseases. MATERIALS AND METHODS: A cross-sectional study was conducted on a sum of 60 age gender balanced; peri-implantitis (n = 20), peri-mucositis (n = 20) and healthy (n = 20) individuals. Unstimulated whole saliva samples were collected and to determine the clinical condition of each subject; the plaque index (PI), gingival index (GI), peri-implant probing pocket depth (PIPD), peri-implant presence of bleeding on probing (BOP) (with/without suppuration) and radiographic signs of crestal bone loss (BL) were measured. The salivary 8-OHdG level was measured using the ELISA method. SOD, GPx activities and MDA levels were determined spectrophotometrically. RESULTS: A total of 60 individuals had evaluations of 318 implants. In comparison to the peri-mucositis and peri-implantitis groups, the healthy group had significantly lower PI and GI scores (p < 0.001). The PIPD value differed amongst the groups, with the peri-implantitis group having the highest value (p < 0.001). Compared to the peri-mucositis and control groups, the peri-implantitis group had a significantly higher BL score (p < 0.001 and p < 0.001, respectively). The peri-implantitis group showed a significantly higher 8-OHdG level (p < 0.001; p < 0.001 respectively) than the peri-mucositis and control groups. Compared to the peri-mucositis and control groups, the peri-implantitis group had a significantly higher MDA level (p < 0.001 and p < 0.001, respectively). The peri-implantitis group had a significantly higher SOD level (p < 0.001 and p < 0.001, respectively) in comparison to the peri-mucositis and control groups. There was no significant difference in GPx levels between the peri-mucositis and control groups (p > 0.05), while the peri-implantitis group had significantly lower GPx levels than the peri-mucositis and control groups (p < 0.001 and p < 0.001, respectively). CONCLUSIONS: Elevated levels of oxidative stress in saliva may indicate the onset of pathological bone loss surrounding the implant and may be an indication of peri-implantitis. CLINICAL RELEVANCE: In peri-implant diseases, changes may occur in the levels of 8-OHdG, MDA, SOD and GPx in saliva, which may lead to a deterioration in the oxidant/antioxidant balance.

Evolutionary Conserved and Divergent Responses to Copper Zinc Superoxide Dismutase Inhibition in Plants.

After an initial evolution in a reducing environment, life got successively challenged by reactive oxygen species (ROS), especially during the great oxidation event (GOE) that followed the development of photosynthesis. Therefore, ROS are deeply intertwined into the physiological, morphological and transcriptional responses of most present-day organisms. Copper-zinc superoxide dismutases (CuZnSODs) evolved during the GOE and are present in charophytes and extant land plants, but nearly absent from chlorophytes. The chemical inhibitor of CuZnSOD, lung cancer screen 1 (LCS-1), could greatly facilitate the study of SODs in diverse plants. Here, we determined the impact of chemical inhibition of plant CuZnSOD activity, on plant growth, transcription and metabolism. We followed a comparative approach by using different plant species, including Marchantia Polymorpha and Physcomitrium patens, representing bryophytes, the sister lineage to vascular plants, and Arabidopsis thaliana. We show that LCS-1 causes oxidative stress in plants and that the inhibition of CuZnSODs provoked a similar core response that mainly impacted glutathione homoeostasis in all plant species analysed. That said, Physcomitrium and Arabidopsis, which contain multiple CuZnSOD isoforms showed a more complex and exacerbated response. In addition, an untargeted metabolomics approach revealed a specific metabolic signature for each plant species. Our comparative analysis exposes a conserved core response at the physiological and transcriptional level towards LCS-1, while the metabolic response largely varies. These differences correlate with the number and localization of the CuZnSOD isoforms present in each species.

Effect of long-term oral administration of the flavonoid quercetin on the antioxidant profile of young and adult reproductive rabbit does.

In industrialized farms, rabbit does undergo intensive production rhythms which overlap lactation and gestation, leading to a high energy mobilization and increasing oxidative stress. Accordingly, we hypothesize that administration of the flavonoid quercetin (QUR) may improve the antioxidant status of young and adult rabbit reproductive females. In this study, the effect of daily oral administration of 300 mg/kg QUR for 8 weeks was assessed on the antioxidant profile of 24 New Zealand × Californian rabbit does, assigned to 4 experimental groups: rearing young (8-16 weeks old) and adult does at the end of their reproductive life (12-14 months old, with at least 3-4 reproductive cycles) treated (YQ and AQ) or not (YC and AC) with QUR, respectively. Plasma glutathione (GSH), as well as serum superoxide dismutase (SOD) and malondialdehyde (MDA) were measured during the experimental period. To assess the health status of the animals, a physical examination was also performed. GSH plasma concentrations were significantly higher in young does at weeks 1 and 4, but not at week 8 of the experiment, irrespectively of QUR administration. An increase in GSH plasma concentration was observed during the 8-week experiment in both AQ and AC groups. Furthermore, QUR administration did not alter either SOD or MDA serum activity and concentration in any group during the experimental period. Physical examination revealed no differences between the experimental groups. In conclusion, under our experimental conditions, QUR did not modify the general clinical or the antioxidant profile of young and adult reproductive rabbit females.

Sodium transport and redox regulation in Saccharomyces cerevisiae under osmotic stress depending on oxygen availability.

This study explores the molecular mechanisms behind the differential responses of Saccharomyces cerevisiae industrial strains (ATCC 9804 and ATCC 13007) to osmotic stress. We observed that, in contrast to ATCC 9804 strain, sodium flux in ATCC 13,007 is not N, N'-dicyclohexylcarbodiimide (DCCD)-sensitive under osmotic stress, suggesting a distinct ion homeostasis mechanism. Under aerobic conditions, osmotic stress increased reduced SH groups by 45% in ATCC 9804 and 34% in ATCC 13,007. In contrast, under microaerophilic conditions, both strains experienced a 50% reduction in thiol groups. Notably, ATCC 13,007 exhibited a 1.5-fold increase in catalase (CAT) activity under aerobic stress compared to standard conditions, while ATCC 9804 showed enhanced CAT activity due to SH group binding. Additionally, superoxide dismutase (SOD) activity was doubled during aerobic growth in both strains, with ATCC 13,007 showing a 1.5-fold higher SOD activity under osmotic stress. The results demonstrate that S. cerevisiae adapts to osmotic stress differently under aerobic and microaerophilic conditions, with aerobic conditions promoting Pma-Ena-Trk interplay, reduced thiol levels and increased catalase activity, while microaerophilic conditions demonstrate Pma-Nha-Trk interplay and shifts redox balance towards oxidized thiol groups and enhance superoxide dismutase activity. Understanding these mechanisms can aid in developing stress-resistant yeast strains for industrial applications.

Myrtenol-Loaded Fatty Acid Nanocarriers Protect Rat Brains Against Ischemia-Reperfusion Injury: Antioxidant and Anti-Inflammatory Effects.

This research investigated the preventive effects of myrtenol (MYR), fatty acid nanocarriers (FANC), and myrtenol-loaded FANC (MYR + FANC) on neurological disturbance, stroke volume, the levels of malondialdehyde (MDA), superoxide dismutase (SOD), and tumor necrosis factor-alpha (TNF-α) in the brain with ischemia-reperfusion injuries induced by middle cerebral artery occlusion (MCAO) in rats. Seventy two Wistar male rats were divided into six main groups. The groups were sham, ischemia-reperfusion group (MACO), MACO-MYR (50 mg/kg), MACO-FANC (50 and 100 mg/kg), and MACO-MYR + FANC (50 mg/kg). Stroke volume, neurological deficit scores, and the brain levels of MDA, SOD, and TNF-α were examined with TTC staining, observation, and ELISA, respectively. Pretreatment with MYR, FANC (100 mg/kg), and MYR + FANC reduced the neurological deficit score and cerebral infarction volume. MYR, FANC (100 mg/kg), and MYR + FANC pretreatment increased and decreased brain SOD and MDA levels compared to MACO group, respectively. The TNF-α level decreased in the MYR + FANC group compared to MCAO and MCAO-MYR groups in the brain. The use of FANC (100 mg/kg), MYR, and MYR + FANC has protective effects against oxidative stress and ischemia-reperfusion injury. FANC probably improve the bioavailability of MYR, as MYR+ FANC had more therapeutic effects on the reduction of ischemia-reperfusion injuries, inflammation, and oxidative stress.

Rhizobium Inoculant and Seed-Applied Fungicide Effects Improve the Drought Tolerance of Soybean Plants as an Effective Agroecological Solution under Climate Change Conditions.

BACKGROUND: Rhizobial inoculation in combination with fungicidal seed treatment is an effective solution for improving soybean resistance to modern climate changes due to the maximum implementation of the plant's stress-protective antioxidant properties and their nitrogen-fixing potential, which will contribute to the preservation of the environment. METHODS: Model ecosystems at different stages of legume-rhizobial symbiosis formation, created by treatment before sowing soybean seeds with a fungicide (fludioxonil, 25 g/L) and inoculation with an active strain of Bradyrhizobium japonicum (titer 109 cells per mL), were subjected to microbiological, biochemical, and physiological testing methods in controlled and field conditions. RESULTS: Seed treatment with fungicide and rhizobia showed different patterns in the dynamics of key antioxidant enzymes in soybean nodules under drought conditions. Superoxide dismutase activity increased by 32.7% under moderate stress, while catalase increased by 90.6% under long-term stress. An increase in the antioxidant enzyme activity induced the regulation of lipoperoxidation processes during drought and after the restoration of irrigation. Regeneration after stress was evident in soybean plants with a combination of fungicide seed treatment and rhizobial inoculant, where enzyme levels and lipoperoxidation processes returned to control plant levels. Applying seed treatment with fungicide and Rhizobium led to the preservation of the symbiotic apparatus functioning in drought conditions. As proof of this, molecular nitrogen fixation by nodules has a higher efficiency of 25.6% compared to soybeans without fungicide treatment. In the field, fungicidal treatment of seeds in a complex with rhizobia inoculant induced prolongation of the symbiotic apparatus functioning in the reproductive period of soybean ontogenesis. This positively affected the nitrogen-fixing activity of soybeans during the pod formation stage by more than 71.7%, as well as increasing soybean yield by 12.7% in the field. CONCLUSIONS: The application of Rhizobium inoculant and fungicide to seeds contributed to the development of antioxidant protection of soybean plants during droughts due to the activation of key enzymatic complexes and regulation of lipoperoxidation processes, which have a positive effect on nitrogen fixation and productivity of soybeans. This is a necessary element in soybean agrotechnologies to improve plant adaptation and resilience in the context of modern climate change.

Quantum refinement in real and reciprocal space using the Phenix and ORCA software.

X-ray and neutron crystallography, as well as cryogenic electron microscopy (cryo-EM), are the most common methods to obtain atomic structures of biological macromolecules. A feature they all have in common is that, at typical resolutions, the experimental data need to be supplemented by empirical restraints, ensuring that the final structure is chemically reasonable. The restraints are accurate for amino acids and nucleic acids, but often less accurate for substrates, inhibitors, small-molecule ligands and metal sites, for which experimental data are scarce or empirical potentials are harder to formulate. This can be solved using quantum mechanical calculations for a small but interesting part of the structure. Such an approach, called quantum refinement, has been shown to improve structures locally, allow the determination of the protonation and oxidation states of ligands and metals, and discriminate between different interpretations of the structure. Here, we present a new implementation of quantum refinement interfacing the widely used structure-refinement software Phenix and the freely available quantum mechanical software ORCA. Through application to manganese superoxide dismutase and V- and Fe-nitrogenase, we show that the approach works effectively for X-ray and neutron crystal structures, that old results can be reproduced and structural discrimination can be performed. We discuss how the weight factor between the experimental data and the empirical restraints should be selected and how quantum mechanical quality measures such as strain energies should be calculated. We also present an application of quantum refinement to cryo-EM data for particulate methane monooxygenase and show that this may be the method of choice for metal sites in such structures because no accurate empirical restraints are currently available for metals.

Sod1-deficient cells are impaired in formation of the modified nucleosides mcm5s2U and yW in tRNA.

Uridine residues present at the wobble position of eukaryotic cytosolic tRNAs often carry a 5-carbamoylmethyl (ncm5), 5-methoxycarbonylmethyl (mcm5), or 5-methoxycarbonylhydroxymethyl (mchm5) side-chain. The presence of these side-chains allows proper pairing with cognate codons and they are particularly important in tRNA species where the U34 residue is also modified with a 2-thio (s2) group. The first step in synthesis of the ncm5, mcm5, and mchm5 side-chains is dependent on the six-subunit Elongator complex, whereas the thiolation of the 2-position is catalyzed by the Ncs6/Ncs2 complex. In both yeast and metazoans, allelic variants of Elongator subunit genes show genetic interactions with mutant alleles of SOD1, which encodes the cytosolic Cu,Zn-superoxide dismutase. However, the cause of these genetic interactions remains unclear. Here, we show that yeast sod1 null mutants are impaired in the formation of 2-thio-modified U34 residues. In addition, the lack of Sod1 induces a defect in the biosynthesis of wybutosine, which is a modified nucleoside found at position 37 of tRNAPhe Our results suggest that these tRNA modification defects are caused by superoxide-induced inhibition of the iron-sulfur cluster-containing Ncs6/Ncs2 and Tyw1 enzymes. Since mutations in Elongator subunit genes generate strong negative genetic interactions with mutant ncs6 and ncs2 alleles, our findings at least partially explain why the activity of Elongator can modulate the phenotypic consequences of SOD1/sod1 alleles. Collectively, our results imply that tRNA hypomodification may contribute to impaired proteostasis in Sod1-deficient cells.

Acute and prolonged effects of Bacillus amyloliquefaciens GF424-derived SOD on antioxidant defense in healthy individuals challenged with intense aerobic exercise.

Reactive oxygen species (ROS) play a vital role in cellular functions but can lead to oxidative stress and contribute to degenerative diseases when produced in excess. Maintaining redox balance is essential and can be achieved through innate defense mechanisms or external antioxidants. Superoxide dismutase (SOD) is a key enzyme that mitigates intracellular oxidative stress by converting harmful free radicals into hydrogen peroxide, which is subsequently neutralized by catalase and glutathione peroxidase. Previous studies have demonstrated the antioxidant capabilities of SOD derived from Bacillus amyloquefaciens GF424 (BA-SOD) in murine models exposed to either irradiation or SOD1 gene deletion. In this study, a randomized clinical trial was conducted to evaluate the antioxidative benefits of BA-SOD in healthy individuals undergoing acute aerobic exercise (AAE). Eighty participants were randomly assigned to receive either BA-SOD or a placebo for 8 weeks. Antioxidant enzyme activities and glutathione levels were measured before, immediately after, and 30 min post-exercise. A single dose of BA-SOD significantly reduced ROS levels induced by AAE, primarily by enhancing SOD activity in erythrocytes and activating glutathione peroxidase. Continuous BA-SOD administration was associated with a sustained increase in catalase activity and elevated levels of reduced glutathione (GSH). Transcriptomic and metabolomic analyses revealed that a single BA-SOD dose facilitated GSH oxidation, as evidenced by decreased levels of serine, glutamine, and glycine, and increased pyroglutamate levels. Additionally, repeated dosing led to increased expression of genes encoding isocitrate dehydrogenase and malic enzyme, which are involved in NADPH synthesis, as well as nicotinamide phosphoribosyl transferase and NAD kinase, which are essential for NADP availability-critical for converting oxidized glutathione (GSSG) back to GSH. These molecular insights align with clinical observations, suggesting that both acute and long-term BA-SOD supplementation may effectively enhance antioxidant defenses and maintain redox balance under oxidative stress conditions.

Expression, Purification, and Anti-UV Irradiation Effect of RsSOD on HCE-T Human Corneal Epithelial Cells.

Superoxide dismutase (SOD) is a class of enzymes that catalyze the disproportionation of superoxide anion radicals into hydrogen peroxide and oxygen. It can remove excessive free radicals in organisms and acts as a potent antioxidant, cleaning free radicals generated by radiation and protecting cells from oxidative damage. In this study, we obtained a MnSOD gene from the radiation-resistant bacterium Radiobacillus sp. (RsSOD) and constructed its recombinant expression vector through gene synthesis. The recombinant RsSOD protein was efficiently expressed using IPTG induction, and purified via repeated freezing and thawing, heating, and DEAE anion-exchange chromatography. The purified RsSOD exhibited an enzyme activity of 2072.5 U/mg. Furthermore, RsSOD was demonstrated to have robust resistance to high temperatures, acid, alkali, and artificial intestinal fluid. Further studies were performed to investigate the radiation resistance of RsSOD against ultraviolet (UV) irradiation in human corneal epithelial (HCE-T) cells. The results indicated that a low concentration of RsSOD (6.25 U/mL) could promote HCE-T cell proliferation and protect these cells from damage caused by both long-term and short-term UV exposure, effectively reducing apoptosis induced by short-term UV irradiation. These findings suggest that the RsSOD protein possesses significant anti-UV irradiation property and is expected to be a candidate for treating ocular radiation-related diseases.

Endogenous hydrogen peroxide positively regulates secretion of a gut-derived peptide in neuroendocrine potentiation of the oxidative stress response in C. elegans.

The gut-brain axis mediates bidirectional signaling between the intestine and the nervous system and is critical for organism-wide homeostasis. Here we report the identification of a peptidergic endocrine circuit in which bidirectional signaling between neurons and the intestine potentiates the activation of the antioxidant response in C. elegans in the intestine. We identify a FMRF-amide-like peptide, FLP-2, whose release from the intestine is necessary and sufficient to activate the intestinal oxidative stress response by promoting the release of the antioxidant FLP-1 neuropeptide from neurons. FLP-2 secretion from the intestine is positively regulated by endogenous hydrogen peroxide (H2O2) produced in the mitochondrial matrix by sod-3/superoxide dismutase, and is negatively regulated by prdx-2/peroxiredoxin, which depletes H2O2 in both the mitochondria and cytosol. H2O2 promotes FLP-2 secretion through the DAG and calciumdependent protein kinase C family member pkc-2 and by the SNAP25 family member aex-4 in the intestine. Together, our data demonstrate a role for intestinal H2O2 in promoting inter-tissue antioxidant signaling through regulated neuropeptide-like protein exocytosis in a gut-brain axis to activate the oxidative stress response.

Superoxide dismutase positively regulates Cu/Zn toxicity tolerance in Sorghum bicolor by interacting with Cu chaperone for superoxide dismutase.

Heavy metal stress threatens plant growth and productivity. In this study, we investigated the effects of CuSO4 and ZnSO4 toxicity on sorghum seedlings, focusing on their impact on biomass, germination rates, growth parameters, antioxidant enzyme activities, gene expression profiles, and stress resistance mechanisms. As a result, eight sorghum superoxide dismutase (SOD) genes were identified, and their evolutionary relationships with cis-acting regulatory elements and their expressional patterns were evaluated. Integrating transcriptomic data revealed a key SOD member SbCSD1 that might contribute to plant abiotic stress resistance. Furthermore, SbCSD1 overexpression enhanced plant tolerance to CuSO4 and ZnSO4 stress by regulating SOD activity and interacting with copper chaperone for superoxide dismutase 1 (CCS1) in the plant nucleus and cytoplasm. Meanwhile, silencing CCS1 in SbCSD1-overexpressing plants revealed that SbCSD1 and CCS1 synergistically contribute to Cu stress tolerance. By integrating transcriptomic and genetic data, herein we provide novel insights into the orchestration of plant responses to heavy-metal stress in sorghum by SOD.

A novel molecular target, superoxide dismutase 1, in ALK inhibitor-resistant lung cancer cells, detected through proteomic analysis.

BACKGROUNDS: To the best of our knowledge, there are no reports of proteomic analysis for the identification of unknown proteins involved in resistance to anaplastic lymphoma kinase (ALK) inhibitors. In this study, we investigated the proteins involved in resistance to alectinib, a representative ALK inhibitor, through proteomic analysis and the possibility of overcoming resistance. METHODS: An ALK-positive lung adenocarcinoma cell line (ABC-11) and the corresponding alectinib-resistant cell line (ABC-11/CHR2) were used. Two-dimensional difference gel electrophoresis (2D DIGE) was performed; the stained gel was scanned and the spots were analyzed using DeCyder TM2D 7.0. Mass spectrometry (MS) with the UltrafleXtreme matrix-assisted laser desorption ionization-tandem time-of-flight (MALDI-TOF/TOF) MS system was performed. For the MS/MS analysis, the samples were spotted on an AnchorChipTM 600 TF plate. The peptide masses obtained in the reflector positive mode were acquired at m/z of 400-6000. MS/MS data were searched against the NCBI protein databases. Growth inhibition was measured using an MTT assay. The isobologram and combination index were calculated based on the median-effect analysis. Western blotting was performed using antibodies, including superoxide dismutase (SOD) 1, MET, ERK, PARP, AKT, and BRCA1. RESULTS: The 2D DIGE for ABC-11 and ABC-11/CHR2 showed different expression levels in about 2000 spots. SOD was identified from spots highly expressed in resistant strains. Western blotting also confirmed SOD1 overexpression in ABC-11/CHR2. siSOD1 enhanced the growth inhibitory effects of alectinib, increased cleaved PARP levels, and decreased pERK, pAKT, and BRCA1 levels with a combination of alectinib. In addition, the combination of LCS-1, an SOD1 inhibitor, and alectinib synergistically suppressed the growth in ABC-11/CHR2, but not in ABC-11. CONCLUSIONS: SOD1 overexpression is thought to be a mechanism for alectinib resistance, suggesting the possibility of overcoming resistance using SOD1 inhibitors.

Priming of Exogenous Salicylic Acid under Field Conditions Enhances Crop Yield through Resistance to Magnaporthe oryzae by Modulating Phytohormones and Antioxidant Enzymes.

This study explores the impact of exogenous salicylic acid (SA) alongside conventional treatment by farmers providing positive (Mancozeb 80 % WP) and negative (water) controls on rice plants (Oryza sativa L.), focusing on antioxidant enzyme activities, phytohormone levels, disease resistance, and yield components under greenhouse and field conditions. In greenhouse assays, SA application significantly enhanced the activities of peroxidase (POX), polyphenol oxidase (PPO), catalase (CAT), and superoxide dismutase (SOD) within 12-24 h post-inoculation (hpi) with Magnaporthe oryzae. Additionally, SA-treated plants showed higher levels of endogenous SA and indole-3-acetic acid (IAA) within 24 hpi compared to the controls. In terms of disease resistance, SA-treated plants exhibited a reduced severity of rice blast under greenhouse conditions, with a significant decrease in disease symptoms compared to negative control treatment. The field study was extended over three consecutive crop seasons during 2021-2023, further examining the efficacy of SA in regular agricultural practice settings. The SA treatment consistently led to a reduction in rice blast disease severity across all three seasons. Yield-related parameters such as plant height, the number of tillers and panicles per hill, grains per panicle, and 1000-grain weight all showed improvements under SA treatment compared to both positive and negative control treatments. Specifically, SA-treated plants yielded higher grain outputs in all three crop seasons, underscoring the potential of SA as a growth enhancer and as a protective agent against rice blast disease under both controlled and field conditions. These findings state the broad-spectrum benefits of SA application in rice cultivation, highlighting its role not only in bolstering plant defense mechanisms and growth under greenhouse conditions but also in enhancing yield and disease resistance in field settings across multiple crop cycles. This research presents valuable insights into the practical applications of SA in improving rice plant resilience and productivity, offering a promising approach for sustainable agriculture practices.