Increase of HCN current in SOD1-associated amyotrophic lateral sclerosis.

The clinical manifestations of sporadic amyotrophic lateral sclerosis (ALS) vary widely. However, the current classification of ALS is mainly based on clinical presentations, while the roles of electrophysiological and biomedical biomarkers remain limited. Herein, we investigated a group of patients with sporadic ALS and an ALS mouse model with superoxide dismutase 1 (SOD1)/G93A transgenes using nerve excitability tests (NET) to investigate axonal membrane properties and chemical precipitation, followed by enzyme-linked immunosorbent assay analysis to measure plasma misfolded protein levels. Six of 19 patients (31.6%) with sporadic ALS had elevated plasma misfolded SOD1 protein levels. In sporadic ALS patients, only those with elevated misfolded SOD1 protein levels showed an increased inward rectification in the current-threshold (I/V) curve and an increased threshold reduction in the hyperpolarizing threshold electrotonus (TE) in the NET study. Two familial ALS patients with SOD1 mutations also exhibited similar electrophysiological patterns of NET. For patients with sporadic ALS showing significantly increased inward rectification in the I/V curve, we noted an elevation in plasma misfolded SOD1 level, but not in total SOD1, misfolded C9orf72, or misfolded phosphorylated TDP43 levels. Computer simulations demonstrated that the aforementioned axonal excitability changes are likely associated with an increase in hyperpolarization-activated cyclic nucleotide-gated (HCN) current. In SOD1/G93A mice, NET also showed an increased inward rectification in the I/V curve, which could be reversed by a single injection of the HCN channel blocker, ZD7288. Daily treatment of SOD1/G93A mice with ZD7288 partially prevented the early motor function decline and spinal motor neuron death. In summary, sporadic ALS patients with elevated plasma misfolded SOD1 exhibited similar patterns of motor axonal excitability changes as familial ALS patients and ALS mice with mutant SOD1 genes, suggesting the existence of SOD1-associated sporadic ALS. The observed NET pattern of increased inward rectification in the I/V curve was attributable to an elevation in the HCN current in SOD1-associated ALS.

Effect of hydro-alcoholic extract of Nigella sativa on cisplatin-induced memory impairment and brain oxidative stress status in male rats.

Objective: Studies have shown the complications of chemotherapy on learning and memory. Empirical evidence suggests that Nigella sativa (NS) has neuroprotective activities. Therefore, the aim of our study was to investigate the effects of NS on cisplatin-induced memory impairment. Materials and Methods: This study was conducted on 40 male rats grouped as: control (saline: 2 ml/kg, intraperitoneally (IP), once weekly/2 weeks), cisplatin (Cis, 2 mg/kg, IP, once weekly/2 weeks), NS (200 mg/kg, IP, once weekly/2 weeks), Cis +NS 200 (2 mg/kg Cis + 200 mg/kg NS, IP, once weekly/2 weeks), and Cis +NS 400 (2 mg/kg Cis + 400 mg/kg NS, IP, once weekly/2 weeks). Morris water maze (MWM) test was used to assess spatial learning and memory. In addition, superoxide dismutase (SOD) activity, and thiol and malondialdehyde (MDA) levels were evaluated in the brain. Results: Cis significantly enhanced the traveled distance and time spent in the target quadrant in the MWM test. Additionally, MDA levels increased in the Cis group, while thiol and SOD decreased in this group. As a result of treatment with NS, behavioral results were reversed in the groups receiving NS compared to the Cis group. Also, NS reduced MDA level but improved SOD and thiol levels in brain tissue samples. Conclusion: NS could improve memory impairment and oxidative stress in animals receiving Cis. Therefore, NS could be used as a potential food supplement to prevent neurotoxicity in patients undergoing chemotherapy.

Shiitake mushroom powder supplementation increase antioxidative activity in dogs.

Introduction: The prevalence of age-related diseases, including obesity (a lipid metabolism disorder), increases with the increase in a dog's lifespan. Most of age-related diseases are associated with oxidative stress by excessive production of reactive oxygen species (ROS) from impaired mitochondrial functions. Safe and effective supplements with antioxidative and anti-inflammatory activities are required to prevent obesity and associated complications. Shiitake mushroom exhibit various functions including antioxidant activity. We investigated the effect of shiitake powder supplementation in healthy dogs. Methods: Shiitake powder was supplemented at a dose of 800 mg/kg body weight/day for 4 weeks. The dose was set as 0.60-0.65 mg/kg/day of eritadenine, a hypocholesterolemic factor. Results: The body weight and body condition score of the dogs did not change after shiitake supplementation. In contrast, plasma total cholesterol concentrations decreased and superoxide dismutase activity and leukocyte sirtuin1 mRNA expression increased significantly in the dogs that received the supplement. Discussion: Oral administration of shiitake powder increased antioxidative activity. The supplement may be useful in ameliorating the signs of age-related diseases, including obesity, in dogs.

Induction of necrosis symptoms by potato virus X in AGO2-silenced tomato plants associates with reduced transcript accumulation of copper chaperon for superoxide dismutase gene.

RNA silencing is a prominent antiviral defense mechanism in plants. When infected with a virus, RNA silencing-deficient plants tend to show exacerbated symptoms along with increased virus accumulation. However, how symptoms are exacerbated is little understood. Here, we investigated the role of the copper chaperon for superoxide dismutase (CCS) 1, in systemic necrosis observed in Argonaute (AGO)2-silenced tomato plants infected with potato virus X (PVX). While infection with the UK3 strain of PVX induced mosaic symptoms in tomato plants, systemic necrosis occurred when AGO2 was silenced. The CCS1 mRNA level was reduced and micro RNA398 (miR398), which potentially target CCS1, was increased in AGO2-knockdown tomato plants infected with PVX-UK3. Ectopic expression of CCS1 using recombinant PVX attenuated necrosis, suggesting that CCS1 alleviates systemic necrosis by activating superoxide dismutases to scavenge reactive oxygen species. Previous reports have indicated a decrease in the levels of CCS1 and superoxide dismutases along with an increased level of miR398 in plants infected with other viruses and viroids, and thus might represent shared regulatory mechanisms that exacerbate symptoms in these plants.

The Ile35 Residue of the ALS-Associated Mutant SOD1 Plays a Crucial Role in the Intracellular Aggregation of the Molecule.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with an unknown pathogenesis. It has been reported that mutations in the gene for Cu/Zn superoxide dismutase (SOD1) cause familial ALS. Mutant SOD1 undergoes aggregation and forms amyloid more easily, and SOD1-immunopositive inclusions have been observed in the spinal cords of ALS patients. Because of this, SOD1 aggregation is thought to be related to the pathogenesis of ALS. Some core regions of amyloid have been identified, but the issue of whether these regions form aggregates in living cells remains unclear, and the mechanism responsible for intracellular SOD1 aggregation also remains unclear. The findings reported in this study indicate that the aggregation of the ALS-linked mutant SOD1-EGFP was significantly enhanced when the BioID2 gene was fused to the N-terminus of the mutant SOD1-EGFP plasmid for cellular expression. Expression of a series of BioID2-(C-terminal deletion peptides of SOD1)-EGFP permitted us to identify 1-35 as a minimal N-terminal sequence and Ile35 as an essential amino acid residue that contributes to the intracellular aggregation of SOD1. The findings also showed that an additional substitution of Ile35 with Ser into the ALS mutant SOD1 resulted in the significant suppression of aggregate formation. The fact that no Ile35 mutations have been reported to date in ALS patients indicates that all ALS mutant SOD1s contain Ile35. Taken together, we propose that Ile35 plays a pivotal role in the aggregation of the ALS-linked SOD1 and that this study will contribute to our understanding of the mechanism responsible for SOD1 aggregation.

Abnormalities in copper status associated with diminished ovarian reserve: A case-control and cross-sectional study.

OBJECTIVE: This study aimed to illustrate the copper status of diminished ovarian reserve in Chinese women, especially the effects of copper, ceruloplasmin, non-ceruloplasmin-bound copper (NCC) and CuZn superoxide dismutase (SOD1). METHODS: This case-control, cross-sectional investigation included women with diminished ovarian reserve (DOR group, n = 35) and matched normal ovarian reserve (NOR group, n = 35). The serum levels of copper, ceruloplasmin, NCC, SOD1, follicle-stimulating hormone, luteinizing hormone, estradiol, testosterone, and anti-Müllerian hormone were tested and analyzed. RESULTS: The serum copper concentrations (60.88%), NCC (54.75%) and SOD1 (54.75%) in the DOR group were significantly higher than those in the NOR group (all P < 0.001), and the concentrations of the three markers were higher in most subgroups (P < 0.001). The correlation analysis verified the correlation between copper status and impaired ovarian function. Additionally, linear regression analysis showed that NCC and SOD1 levels were negatively correlated with anti-Müllerian hormone (P < 0.05 or 0.001). CONCLUSION: Our exploration found significant increases in copper, NCC and SOD1 levels in DOR and suggests a possible link. Copper status is expected to serve as the predictive marker for DOR.

Enzymatic biomarkers of oxidative stress in patients with depressive disorders. A systematic review.

Oxidative stress (OS) results from the imbalance between the production of reactive oxygen species and the body's antioxidant mechanisms and is associated with various diseases, including depression. Antioxidants protect cells by neutralizing free radicals and include enzymatic components such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), and glutathione S-transferase (GST). The concentration of these biomarkers can quantify OS. This research aimed to gather available information published in the last ten years about the concentration of enzymatic OS biomarkers in samples from patients with depressive disorders. METHOD: A systematic review was conducted following the PRISMA guidelines, including original scientific articles that evaluated enzymatic OS biomarkers in participants with depressive disorders, using the keywords and boolean operators "superoxide dismutase" OR "catalase" OR "glutathione" AND "depress*" in the databases PubMed, SAGE Journals, DOAJ, Scielo, Dialnet, and Redalyc. RESULTS: The initial search showed 614 results, with only 28 articles meeting the selection criteria. It was observed that all evaluated oxidative stress enzymatic markers showed a significant increase or decrease in patients with depressive disorders, due to a wide variability in the depressive disorders studied, the type of biological sample analyzed, and the techniques used. CONCLUSION: There is evidence of the relationship between enzymatic OS biomarkers and depressive disorders, but additional studies are needed to clarify the nature of this relationship, particularly considering the different types of depressive disorders.

Predicting Field Effectiveness of Endophytic Bacillus subtilis Inoculants for Common Bean Using Morphometric and Biochemical Markers.

According to four field experiments, after the inoculation of Phaseolus vulgaris L. cultivar Ufimskaya with the commercial strain Bacillus subtilis 26D and the promising strain B. subtilis 10-4, it was found that inoculation with B. subtilis 10-4 improved seed productivity (SP) by 31-41% per plant, but only in dry years. In contrast, all 4 years of inoculation with B. subtilis 26D were ineffective or neutral. It was intended to determine the growing and biochemical characteristics of inoculated 7-day-old plants, which correlate with the field SP of bacterial preparations. The SP of inoculated plants (average of 4 years) correlated with root length (0.83), MDA content (-0.98), and catalase (CAT) activity in roots (-0.96) of week-old seedlings. High correlation coefficients between the H2O2 content in the roots and SP (0.89 and 0.77), as well as between the H2O2 content in shoots and SP (0.98 and 0.56), were observed only in two dry years, when the influence of bacteria was detected. These physiological indicators were identified as potential markers for predicting the effectiveness of the endophytic symbiosis between bean plants and B. subtilis strains. The findings may be used to develop effective microbial-based, eco-friendly technologies for bean production.

GPCR-Gα13 Involvement in Mitochondrial Function, Oxidative Stress, and Prostate Cancer.

Gα13 and Gα12, encoded by the GNA13 and GNA12 genes, respectively, are members of the G12 family of Gα proteins that, along with their associated Gßγ subunits, mediate signaling from specific G protein-coupled receptors (GPCRs). Advanced prostate cancers have increased expression of GPCRs such as CXC Motif Chemokine Receptor 4 (CXCR4), lysophosphatidic acid receptor (LPAR), and protease activated receptor 1 (PAR-1). These GPCRs signal through either the G12 family, or through Gα13 exclusively, often in addition to other G proteins. The effect of Gα13 can be distinct from that of Gα12, and the role of Gα13 in prostate cancer initiation and progression is largely unexplored. The oncogenic effect of Gα13 on cell migration and invasion in prostate cancer has been characterized, but little is known about other biological processes such as mitochondrial function and oxidative stress. Current knowledge on the link between Gα13 and oxidative stress is based on animal studies in which GPCR-Gα13 signaling decreased superoxide levels, and the overexpression of constitutively active Gα13 promoted antioxidant gene activation. In human samples, mitochondrial superoxide dismutase 2 (SOD2) correlates with prostate cancer risk and prognostic Gleason grade. However, overexpression of SOD2 in prostate cancer cells yielded conflicting results on cell growth and survival under basal versus oxidative stress conditions. Hence, it is necessary to explore the effect of Gα13 on prostate cancer tumorigenesis, as well as the effect of Gα13 on SOD2 in prostate cancer cell growth under oxidative stress conditions.

Mitochondrial Targeted Cerium Oxide Nanoclusters for Radiation Protection and Promoting Hematopoiesis.

Purpose: Mitochondrial oxidative stress is an important factor in cell apoptosis. Cerium oxide nanomaterials show great potential for scavenging free radicals and simulating superoxide dismutase (SOD) and catalase (CAT) activities. To solve the problem of poor targeting of cerium oxide nanomaterials, we designed albumin-cerium oxide nanoclusters (TPP-PCNLs) that target the modification of mitochondria with triphenyl phosphate (TPP). TPP-PCNLs are expected to simulate the activity of superoxide dismutase, continuously remove reactive oxygen species, and play a lasting role in radiation protection. Methods: First, cerium dioxide nanoclusters (CNLs), polyethylene glycol cerium dioxide nanoclusters (PCNLs), and TPP-PCNLs were characterized in terms of their morphology and size, ultraviolet spectrum, dispersion stability and cellular uptake, and colocalization Subsequently, the anti-radiation effects of TPP-PCNLs were investigated using in vitro and in vivo experiments including cell viability, apoptosis, comet assays, histopathology, and dose reduction factor (DRF). Results: TPP-PCNLs exhibited good stability and biocompatibility. In vitro experiments indicated that TPP-PCNLs could not only target mitochondria excellently but also regulate reactive oxygen species (ROS)levels in whole cells. More importantly, TPP-PCNLs improved the integrity and functionality of mitochondria in irradiated L-02 cells, thereby indirectly eliminating the continuous damage to nuclear DNA caused by mitochondrial oxidative stress. TPP-PCNLs are mainly targeted to the liver, spleen, and other extramedullary hematopoietic organs with a radiation dose reduction factor of 1.30. In vivo experiments showed that TPP-PCNLs effectively improved the survival rate, weight change, hematopoietic function of irradiated animals. Western blot experiments have confirmed that TPP-PCNLs play a role in radiation protection by regulating the mitochondrial apoptotic pathway. Conclusion: TPP-PCNLs play a radiologically protective role by targeting extramedullary hematopoietic organ-liver cells and mitochondria to continuously clear ROS.

SOD1 inhibition enhances sorafenib efficacy in HBV-related hepatocellular carcinoma by modulating PI3K/Akt/mTOR pathway and ROS-mediated cell death.

Hepatitis B Virus (HBV) infection significantly elevates the risk of hepatocellular carcinoma (HCC), with the HBV X protein (HBx) playing a crucial role in cancer progression. Sorafenib, the primary therapy for advanced HCC, shows limited effectiveness in HBV-infected patients due to HBx-related resistance. Numerous studies have explored combination therapies to overcome this resistance. Sodium diethyldithiocarbamate (DDC), known for its anticancer effects and its inhibition of superoxide dismutase 1 (SOD1), is hypothesized to counteract sorafenib (SF) resistance in HBV-positive HCCs. Our research demonstrates that combining DDC with SF significantly reduces HBx and SOD1 expressions in HBV-positive HCC cells and human tissues. This combination therapy disrupts the PI3K/Akt/mTOR signalling pathway and promotes apoptosis by increasing reactive oxygen species (ROS) levels. These cellular changes lead to reduced tumour viability and enhanced sensitivity to SF, as evidenced by the synergistic suppression of tumour growth in xenograft models. Additionally, DDC-mediated suppression of SOD1 further enhances SF sensitivity in HBV-positive HCC cells and xenografted animals, thereby inhibiting cancer progression more effectively. These findings suggest that the DDC-SF combination could serve as a promising strategy for overcoming SF resistance in HBV-related HCC, potentially optimizing therapy outcomes.

[Cell membrane-penetrating capacity of hPP10-Cu, Zn-SOD fusion protein and its antioxidant and anti-inflammatory activity].

OBJECTIVE: To investigate the cell membrane-penetrating capacity of human cell-penetrating peptide hPP10 carrying human antioxidant protein Cu-Zn superoxide dismutase (Cu, Zn-SOD) and assess the antioxidant and anti-inflammatory activity of these fusion proteins. METHODS: The fusion protein hPP10-Cu, Zn-SOD was obtained by genetic engineering and identified by Western blotting. The membrane-penetrating ability of the fusion protein was evaluated by immunofluorescence assay, fluorescence colocalization assay and Western blotting, its SOD enzyme activity was detected using a commercial kit, and its effect on cell viability was assessed with MTT assay. In a HEK293 cell model of H2O2-induced oxidative stress, the effect of hPP10-Cu, Zn-SOD on cell apoptosis was analyzed with flow cytometry and RT-qPCR, and its antioxidant effect was assessed using reactive oxygen species (ROS) assay; its anti-inflammatory effect was evaluated in mouse model of TPA-induced ear inflammation by detecting expression of the inflammatory factors using RT-qPCR, Western blotting and immunohistochemistry. RESULTS: The fusion protein hPP10-Cu, Zn-SOD was successfully obtained. Immunofluorescence assay confirmed obvious membrane penetration of this fusion protein in HEK293 cells, localized both in the cell membrane and the cell nuclei after cell entry. hPP10-Cu, Zn-SOD at the concentration of 5 µmol/L exhibited strong antioxidant activity with minimal impact on cell viability at the concentration up to 10 µmol/L. The fusion protein obviously inhibited apoptosis and decreased intracellular ROS level in the oxidative stress cell model and significantly reduced mRNA and protein expression of the inflammatory factors in the mouse model of ear inflammation. CONCLUSION: The fusion protein hPP10-Cu, Zn-SOD capable of penetrating the cell membrane possesses strong antioxidant and anti-inflammatory activities with only minimal cytotoxicity, demonstrating the value of hPP10 as an efficient drug delivery vector and the potential of hPP10-Cu, Zn-SOD in the development of skincare products.

Effect of salt stress on plant regeneration efficiency in primed and non-primed seed's calli of rice (Oryza sativa L.) variety Swarna.

This study leads with the primed seeds of rice (var. Swarna) with distilled water (D.W.) and various concentrations of Mg(NO3)2 (0-8 mM)/Kinetin (0-5 ppm) alone or in combination with screen out the regeneration medium induced tolerance level of NaCl. To fulfill the objective, the primed and non-primed rice seeds were inoculated in MS medium supplemented with 30 gL-1 maltose + 1 gL-1 casein hydrolysate and 2 mgL-1 of 2,4-D for callus induction and cultured up to 45 days in two sets: one set for regeneration purpose in NaCl-induced regeneration medium and another set was used to study the physiological potentiality of the callus. The 45-day-old calli were transferred into regeneration medium MSR (MS medium for regeneration) (BAP: NAA: Kinetin = 4:1:1) containing NaCl with a concentration range of 0 to 300 mM. The number of regenerating calli and shoot regeneration percentage, number of plantlets obtained from one callus, recovery of plantlets from each concentration of NaCl and proline estimation from the leaf of the regenerated plantlets were determined from one set obtained after 45 days. The calli obtained from another set after 45 days, the frequencies of total and embryogenic calli induction percentage, fresh and dry weights, proline content, nitrate reductase and superoxide dismutase activities were measured. The calli obtained from 2.5 ppm kinetin + 4 mM Mg(NO3)2 primed seeds were showed best result as compared to the other treatments for the above-mentioned parameters in different concentrations of NaCl-induced medium and survive up to 200 mM concentrations of NaCl.

Exogenous Sodium Nitroprusside Affects the Redox System of Wheat Roots Differentially Regulating the Activity of Antioxidant Enzymes under Short-Time Osmotic Stress.

Nitric oxide (NO) is a multifunctional signalling molecule involved in the regulation of plant ontogenesis and adaptation to different adverse environmental factors, in particular to osmotic stress. Understanding NO-induced plant protection is important for the improvement of plant stress tolerance and crop productivity under global climate changes. The root system is crucial for plant survival in a changeable environment. Damages that it experiences under water deficit conditions during the initial developmental periods seriously affect the viability of the plants. This work was devoted to the comparative analysis of the pretreatment of wheat seedlings through the root system with NO donor sodium nitroprusside (SNP) for 24 h on various parameters of redox homeostasis under exposure to osmotic stress (PEG 6000, 12%) over 0.5-24 h. The active and exhausted solutions of SNP, termed as (SNP/+NO) and (SNP/-NO), respectively, were used in this work at a concentration of 2 × 10-4 M. Using biochemistry and light microscopy methods, it has been revealed that osmotic stress caused oxidative damages and the disruption of membrane cell structures in wheat roots. PEG exposure increased the production of superoxide (O2•-), hydrogen peroxide (H2O2), malondialdehyde (MDA), and the levels of electrolyte leakage (EL) and lipid peroxidation (LPO). Stress treatment enhanced the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), the excretion of proline, and the rate of cell death and inhibited their division. Pretreatment with (SNP/+NO) decreased PEG-induced root damages by differently regulating the antioxidant enzymes under stress conditions. Thus, (SNP/+NO) pretreatment led to SOD, APX, and CAT inhibition during the first 4 h of stress and stimulated their activity after 24 h of PEG exposure when compared to SNP-untreated or (SNP/-NO)-pretreated and stress-subjected plants. Osmotic stress triggered the intense excretion of proline by roots into the external medium. Pretreatment with (SNP/+NO) in contrast with (SNP/-NO) additionally increased stress-induced proline excretion. Our results indicate that NO is able to mitigate the destructive effects of osmotic stress on the roots of wheat seedlings. However, the mechanisms of NO protective action may be different at certain periods of stress exposure.

Genetic predicted causal inferences between antioxidants and birth weight.

Observational studies have suggested a relationship between antioxidants and birth weight. However, the causal association remains unclear. The aim of this study was to assess the causal relationship between antioxidants and birth weight. Genome wide association study (GWAS) summary statistics for 4 endogenous and 7 exogenous antioxidants, as well as birth weight were obtained from GWAS studies and UK biobank. A two-sample Mendelian randomization (MR) analysis was conducted with fixed-effects model inverse variance weighted (IVW) as the primary analytical method, while MR Egger and weighted median used as auxiliary. A series of sensitivity analyses were conducted to verify the robustness of the results. The MR results revealed that genetically predicted higher superoxide dismutase (SOD) (ß = 0.025; 95% CI: 0.008, 0.043; p = 0.005) and zinc (ß = 0.030; 95% CI: 0.013, 0.047; p = 0.001) levels were associated with higher birth weight. Sensitivity analysis verified the robustness of the MR results. Our study reinforced the existing evidence supporting a significant positive association between SOD and zinc with birth weight, providing new genetic evidence for antioxidant supplementation during pregnancy to prevent low birth weight infants. Further deeper comprehension studies are warranted to confirm these findings.

Role of copper and SOD3-mediated extracellular redox regulation in tumor progression.

Copper (Cu), an essential micronutrient, participates in several physiological processes, including cell proliferation and development. Notably, the disturbance of Cu homeostasis promotes tumor progression through the generation of oxidative stress. Chronic or excessive accumulation of reactive oxygen species (ROS) causes lipid peroxidation, protein denaturation, and enzyme inactivation, which leads to a breakdown of intracellular homeostasis and exacerbates tumor progression. The disruption of the ROS scavenging mechanism also reduces resistance to oxidative stress, leading to further deterioration in a disease state, and maintenance of redox homeostasis is thought to inhibit the onset and progression of various diseases. Superoxide dismutase 3 (SOD3), a Cu-containing secretory antioxidative enzyme, plays a key role in extracellular redox regulation, and the significant reduction in SOD3 facilitates tumor progression. Furthermore, the significant induction of SOD3 participates in tumor metastasis. This review focuses on the role of Cu homeostasis and antioxidative enzymes, including SOD3, in tumor progression, to help clarify the role of redox regulation.

Superoxide dismutase and neurological disorders.

Superoxide dismutase (SOD) is a common antioxidant enzyme found majorly in living cells. The main physiological role of SOD is detoxification and maintain the redox balance, acts as a first line of defence against Reactive nitrogen species (RNS), Reactive oxygen species (ROS), and other such potentially hazardous molecules. SOD catalyses the conversion of superoxide anion free radicals (O 2 -.) into molecular oxygen (O 2) and hydrogen peroxide (H 2O 2) in the cells. Superoxide dismutases (SODs) are expressed in neurons and glial cells throughout the CNS both intracellularly and extracellularly. Endogenous oxidative stress (OS) linked with enlarged production of reactive oxygen metabolites (ROMs), inflammation, deregulation of redox balance, mitochondrial dysfunction and bioenergetic crisis are found to be prerequisite for neuronal loss in neurological diseases. Clinical and genetic studies indicate a direct correlation between mutations in SOD gene and neurodegenerative diseases, like Amyotrophic Lateral Sclerosis (ALS), Huntington's disease (HD), Parkinson's Disease (PD) and Alzheimer's Disease (AD). Therefore, inhibitors of OS are considered as an optimistic approach to prevent neuronal loss. SOD mimetics like Metalloporphyrin Mn (II)-cyclic polyamines, Nitroxides and Mn (III)- Salen complexes are designed and used as therapeutic extensively in the treatment of neurological disorders. SODs and SOD mimetics are promising future therapeutics in the field of various diseases with OS-mediated pathology.

Sirtuin 3-activated superoxide dismutase 2 mediates fluoride-induced osteoblastic differentiation in vitro and in vivo by down-regulating reactive oxygen species.

Skeletal fluorosis is a chronic metabolic bone disease caused by long-term excessive fluoride intake. Abnormal differentiation of osteoblasts plays an important role in disease progression. Research on the mechanism of fluoride-mediated bone differentiation is necessary for the prevention and treatment of skeletal fluorosis. In the present study, a rat model of fluorosis was established by exposing it to drinking water containing 50 mg/L F-. We found that fluoride promoted Runt-related transcription factor 2 (RUNX2) as well as superoxide dismutase 2 (SOD2) and sirtuin 3 (SIRT3) expression in osteoblasts of rat bone tissue. In vitro, we also found that 4 mg/L sodium fluoride promoted osteogenesis-related indicators as well as SOD2 and SIRT3 expression in MG-63 and Saos-2 cells. In addition, we unexpectedly discovered that fluoride suppressed the levels of reactive oxygen species (ROS) and mitochondrial reactive oxygen species (mtROS) in osteoblasts. When SOD2 or SIRT3 was inhibited in MG-63 cells, fluoride-decreased ROS and mtROS were alleviated, which in turn inhibited fluoride-promoted osteogenic differentiation. In conclusion, our results suggest that SIRT3/SOD2 mediates fluoride-promoted osteoblastic differentiation by down-regulating reactive oxygen species.

The repertoire of iron superoxide dismutases from Leishmania infantum as targets in the search for therapeutic agents against leishmaniasis.

Species of Leishmania and Trypanosoma genera are the causative agents of relevant parasitic diseases. Survival inside their hosts requires the existence of a potent antioxidant enzymatic machinery. Four iron superoxide dismutases have been described in trypanosomatids (FeSODA, FeSODB1, FeSODB2, and FeSODC) that hold a potential as therapeutic targets. Nonetheless, very few studies have been developed that make use of the purified enzymes. Moreover, FeSODC remains uncharacterised in Leishmania. In this work, for the first time, we describe the purification and enzymatic activity of recombinant versions of the four Leishmania FeSOD isoforms and establish an improved strategy for developing inhibitors. We propose a novel parameter [(V*cyt. c - Vcyt. c)/Vcyt. c] which, in contrast to that used in the classical cytochrome c reduction assay, correlates linearly with enzyme concentration. As a proof of concept, we determine the IC50 values of two ruthenium carbosilane metallodendrimers against these isoforms.

MiR398b Targets Superoxide Dismutase Genes in Soybean in Defense Against Heterodera glycines via Modulating Reactive Oxygen Species Homeostasis.

MicroRNAs play crucial roles in plant defense responses. However, the underlying mechanism by which miR398b contributes to soybean responses to soybean cyst nematode (Heterodera glycines) remains elusive. In this study, by using Agrobacterium rhizogenes-mediated transformation of soybean hairy roots, we observed that miR398b and target genes GmCCS and GmCSD1b played vital functions in soybean-H. glycines interaction. The study revealed that the abundance of miR398b was downregulated by H. glycines infection, and overexpression of miR398b enhanced the susceptibility of soybean to H. glycines. Conversely, silencing of miR398b improved soybean resistance to H. glycines. Detection assays revealed that miR398b rapidly senses stress-induced reactive oxygen species, leading to the repression of target genes GmCCS and GmCSD1b and regulating the accumulation of plant defense genes against nematode infection. Moreover, exogenous synthetic ds-miR398b enhanced soybean sensitivity to H. glycines by modulating H2O2 and O2- levels. Functional analysis demonstrated that overexpression of GmCCS and GmCSD1b in soybean enhanced resistance to H. glycines. RNA interference-mediated repression of GmCCS and GmCSD1b in soybean increased susceptibility to H. glycines. RNA sequencing revealed that a majority of differentially expressed genes in overexpressed GmCCS were associated with oxidative stress. Overall, the results indicate that miR398b targets superoxide dismutase genes, which negatively regulate soybean resistance to H. glycines via modulating reactive oxygen species levels and defense signals.