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Journal of Applied Microbiology Nov 2018Further investigations of the novel biological functions of SodA in Salmonella enterica serovar typhimurium (Salm. typhimurium).
AIMS
Further investigations of the novel biological functions of SodA in Salmonella enterica serovar typhimurium (Salm. typhimurium).
METHODS AND RESULTS
A deletion mutant of sodA in Salm. typhimurium was constructed and its biological characteristics were analysed. More specifically, the roles of superoxide dismutase (SOD) in resistance to environmental stresses and serum, biofilm formation, epithelial cell adherence and invasion were investigated. Inactivation of sodA gene resulted in a slightly reduced growth rate, low SOD activity and increased susceptibility to reactive oxygen species and chicken serum. However, SodA was not involved in the motility of Salm. typhimurium. In addition, the sodA mutant exhibited a decreased capacity to form biofilm as well as to adhere and invade to HeLa cells, compared to the wild-type and complemented strains.
CONCLUSIONS
Salmonella typhimurium SOD appears to play an important role in resistance to serum and oxidative stress, biofilm formation, adherence to and invasion of epithelial cells.
SIGNIFICANCE AND IMPACT OF THE STUDY
This study illustrates the novel roles of SodA in serum resistance and biofilm formation in Salm. typhimurium, which may provide a candidate for the biofilm eradication and prevention of infections.
Topics: Bacterial Adhesion; Bacterial Proteins; Biofilms; HeLa Cells; Humans; Salmonella typhimurium; Stress, Physiological; Superoxide Dismutase; Virulence
PubMed: 29989280
DOI: 10.1111/jam.14044 -
Toxins Feb 2019Aflatoxin contamination of crops is a worldwide problem, and elucidation of the regulatory mechanism of aflatoxin production, for example relative to the...
Aflatoxin contamination of crops is a worldwide problem, and elucidation of the regulatory mechanism of aflatoxin production, for example relative to the oxidative⁻antioxidative system, is needed. Studies have shown that oxidative stress induced by reactive oxygen species promotes aflatoxin production. However, superoxide has been suggested to have the opposite effect. Here, we investigated the effects of the superoxide generator, paraquat, and externally added superoxide dismutase (SOD) on aflatoxin production in . Paraquat with an IC value of 54.9 µM inhibited aflatoxin production without affecting fungal growth. It increased cytosolic and mitochondrial superoxide levels and downregulated the transcription of aflatoxin biosynthetic cluster genes, including , a key regulatory protein. The addition of bovine Cu/ZnSOD to the culture medium suppressed the paraquat-induced increase in superoxide levels, but it did not fully restore paraquat-inhibited aflatoxin production because bovine Cu/ZnSOD with an IC value of 17.9 µg/mL itself inhibited aflatoxin production. Externally added bovine Cu/ZnSOD increased the SOD activity in fungal cell extracts and upregulated the transcription of genes encoding Cu/ZnSOD and alcohol dehydrogenase. These results suggest that intracellular accumulation of superoxide impairs aflatoxin production by downregulating expression, and that externally added Cu/ZnSOD also suppresses aflatoxin production by a mechanism other than canonical superoxide elimination activity.
Topics: Aflatoxins; Aspergillus flavus; Genes, Fungal; Paraquat; Superoxide Dismutase; Superoxides
PubMed: 30759855
DOI: 10.3390/toxins11020107 -
International Journal of Molecular... Feb 2023Copper-zinc superoxide dismutase 1 (SOD1) has long been recognized as a major redox enzyme in scavenging superoxide radicals. However, there is little information on its...
Copper-zinc superoxide dismutase 1 (SOD1) has long been recognized as a major redox enzyme in scavenging superoxide radicals. However, there is little information on its non-canonical role and metabolic implications. Using a protein complementation assay (PCA) and pull-down assay, we revealed novel protein-protein interactions (PPIs) between SOD1 and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ) or epsilon (YWHAE) in this research. Through site-directed mutagenesis of SOD1, we studied the binding conditions of the two PPIs. Forming the SOD1 and YWHAE or YWHAZ protein complex enhanced enzyme activity of purified SOD1 in vitro by 40% ( < 0.05) and protein stability of over-expressed intracellular YWHAE (18%, < 0.01) and YWHAZ (14%, < 0.05). Functionally, these PPIs were associated with lipolysis, cell growth, and cell survival in HEK293T or HepG2 cells. In conclusion, our findings reveal two new PPIs between SOD1 and YWHAE or YWHAZ and their structural dependences, responses to redox status, mutual impacts on the enzyme function and protein degradation, and metabolic implications. Overall, our finding revealed a new unorthodox role of SOD1 and will provide novel perspectives and insights for diagnosing and treating diseases related to the protein.
Topics: Humans; Copper; HEK293 Cells; Superoxide Dismutase; Superoxide Dismutase-1; Superoxides
PubMed: 36834640
DOI: 10.3390/ijms24043230 -
Genetics Oct 2023Oxidative stress can damage DNA and thereby contribute to genome instability. To avoid an imbalance or overaccumulation of reactive oxygen species (ROS), cells are...
Oxidative stress can damage DNA and thereby contribute to genome instability. To avoid an imbalance or overaccumulation of reactive oxygen species (ROS), cells are equipped with antioxidant enzymes that scavenge excess ROS. Cells lacking the RecQ-family DNA helicase Sgs1, which contributes to homology-dependent DNA break repair and chromosome stability, are known to accumulate ROS, but the origin and consequences of this oxidative stress phenotype are not fully understood. Here, we show that the sgs1 mutant exhibits elevated mitochondrial superoxide, increased mitochondrial mass, and accumulation of recombinogenic DNA lesions that can be suppressed by antioxidants. Increased mitochondrial mass in the sgs1Δ mutant is accompanied by increased mitochondrial branching, which was also inducible in wildtype cells by replication stress. Superoxide dismutase Sod2 genetically interacts with Sgs1 in the suppression of nuclear chromosomal rearrangements under paraquat (PQ)-induced oxidative stress. PQ-induced chromosome rearrangements in the absence of Sod2 are promoted by Rad51 recombinase and the polymerase subunit Pol32. Finally, the dependence of chromosomal rearrangements on the Rev1/Pol ζ mutasome suggests that under oxidative stress successful DNA synthesis during DNA break repair depends on translesion DNA synthesis.
Topics: Antioxidants; DNA; Genomic Instability; Oxidative Stress; Reactive Oxygen Species; RecQ Helicases; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Superoxide Dismutase
PubMed: 37638880
DOI: 10.1093/genetics/iyad147 -
Neuroendocrinology 2022The present study was designed to evaluate the therapeutic efficacy of melatonin and insulin coadministration in diabetes-induced renal injury in rats.
INTRODUCTION
The present study was designed to evaluate the therapeutic efficacy of melatonin and insulin coadministration in diabetes-induced renal injury in rats.
RESEARCH DESIGN AND METHODS
Diabetes was achieved by giving streptozotocin (15 mg/kg) for 6 consecutive days. The diabetic condition was confirmed by assessing the blood glucose level; animals having blood glucose levels above 250 mg were considered as diabetic. Following the confirmation, animals were randomly divided into different experimental groups, viz group I served as the control (CON), group II diabetic (D), group III D+melatonin (MEL), group IV D+insulin (INS), group V D+MEL+INS, group VI D+glibenclamide (GB), group VII CON+MEL, group VIII CON+INS, and group IX CON+GB. Following the completion of the experimental period, animals were sacrificed, blood was collected via a retro-orbital puncture, and kidneys were harvested. Diabetic rats exhibited a significant increment in blood glucose and biochemical indexes of renal injury (tubular disruption, swollen glomeruli with loss of glomerular spaces, and distortion of the endothelial lining) including augmented levels of serum creatinine, urea, uric acid, Na+, and K+, and inhibition/suppression of the activity of glutathione (GSH) peroxidase, GSH reductase, glucose-6-phosphate dehydrogenase, and GSH-S-transferase in the renal cortex.
RESULTS
By examining thiobarbiturate reactive substances, reduced GSH, superoxide dismutase activity, and catalase activity in the renal cortex of control and diabetic rats, it was documented that treatment with melatonin or insulin alone or in combination showed a significant ad integrum recovery of GSH-dependent antioxidative enzymatic activities. Melatonin and insulin coadministration caused greater reductions in circulating tumor necrosis factor-α, tumor growth factor-β1, interleukin (IL)-1β, and IL-6 levels in diabetic rats, whereas IL-10 levels increased, as compared to each treatment alone. Diabetic rats showed a significant increase in the expression of both MT1 and MT2 melatonin receptor genes. Melatonin or insulin treatment alone or in combination resulted in significant restoration of the relative expression of both melatonin receptors in the renal cortex.
CONCLUSION
The coadministration of exogenous melatonin and insulin abolished many of the deleterious effects of type 1 diabetes on rat renal function.
Topics: Animals; Antioxidants; Blood Glucose; Diabetes Mellitus, Experimental; Insulin; Kidney; Melatonin; Oxidative Stress; Rats; Superoxide Dismutase
PubMed: 34673653
DOI: 10.1159/000520280 -
ACS Infectious Diseases Jun 2018Superoxide anion radical is generated as a natural byproduct of aerobic metabolism but is also produced as part of the oxidative burst of the innate immune response... (Review)
Review
Superoxide anion radical is generated as a natural byproduct of aerobic metabolism but is also produced as part of the oxidative burst of the innate immune response design to kill pathogens. In living systems, superoxide is largely managed through superoxide dismutases (SODs), families of metalloenzymes that use Fe, Mn, Ni, or Cu cofactors to catalyze the disproportionation of superoxide to oxygen and hydrogen peroxide. Given the bursts of superoxide faced by microbial pathogens, it comes as no surprise that SOD enzymes play important roles in microbial survival and virulence. Interestingly, microbial SOD enzymes not only detoxify host superoxide but also may participate in signaling pathways that involve reactive oxygen species derived from the microbe itself, particularly in the case of eukaryotic pathogens. In this Review, we will discuss the chemistry of superoxide radicals and the role of diverse SOD metalloenzymes in bacterial, fungal, and protozoan pathogens. We will highlight the unique features of microbial SOD enzymes that have evolved to accommodate the harsh lifestyle at the host-pathogen interface. Lastly, we will discuss key non-SOD superoxide scavengers that specific pathogens employ for defense against host superoxide.
Topics: Animals; Bacteria; Biological Warfare; Chemical Warfare; Fungi; Host-Pathogen Interactions; Humans; Hydrogen Peroxide; Metals; NADPH Oxidases; Oxidation-Reduction; Parasites; Reactive Oxygen Species; Superoxide Dismutase; Superoxides
PubMed: 29517910
DOI: 10.1021/acsinfecdis.8b00026 -
American Journal of Respiratory Cell... Feb 2017
Topics: Animals; Disease Models, Animal; Humans; Mice; Respiratory Distress Syndrome; Superoxide Dismutase
PubMed: 28145771
DOI: 10.1165/rcmb.2016-0407ED -
Acta Biochimica Polonica 2018Superoxide dismutase 1 (SOD1) is a metalloenzyme that catalyzes the disproportionation of superoxide into molecular oxygen and hydrogen peroxide. In this study, the...
Superoxide dismutase 1 (SOD1) is a metalloenzyme that catalyzes the disproportionation of superoxide into molecular oxygen and hydrogen peroxide. In this study, the human SOD1 (hSOD1) gene was cloned, expressed and purified. The hSOD1 gene was amplified from a pool of Bxpc3 cell cDNAs by PCR and cloned into expression vector pET-28a (+). The recombinant soluble hSOD1 was expressed in E. coli BL21 (DE3) at 37°C and purified using nickel column affinity chromatography. Soluble hSOD1 was produced with a yield of 5.9 μg/mL medium. As metal ions can have a certain influence on protein structure and activity, we researched the influences of different concentrations of Cu and Zn on hSOD1 activity at induction and the time of activity detection. The results implied that Cu and Zn do not enhance SOD1 expression and solubility; they can, however, improve the catalytic activity at induction. Meanwhile, Cu and Zn also enhanced the enzyme activity at the time of detection. Furthermore, most other bivalent cations had the potential to replace Zn and Cu, and also improved enzyme activity at the time of detection.
Topics: Catalysis; Cations, Divalent; Cloning, Molecular; Copper; Escherichia coli; Humans; Recombinant Proteins; Superoxide Dismutase-1; Zinc
PubMed: 29850654
DOI: 10.18388/abp.2017_2350 -
The Journal of Biological Chemistry Mar 2018The copper-containing superoxide dismutases (SODs) represent a large family of enzymes that participate in the metabolism of reactive oxygen species by... (Review)
Review
The copper-containing superoxide dismutases (SODs) represent a large family of enzymes that participate in the metabolism of reactive oxygen species by disproportionating superoxide anion radical to oxygen and hydrogen peroxide. Catalysis is driven by the redox-active copper ion, and in most cases, SODs also harbor a zinc at the active site that enhances copper catalysis and stabilizes the protein. Such bimetallic Cu,Zn-SODs are widespread, from the periplasm of bacteria to virtually every organelle in the human cell. However, a new class of copper-containing SODs has recently emerged that function without zinc. These copper-only enzymes serve as extracellular SODs in specific bacteria ( Mycobacteria), throughout the fungal kingdom, and in the fungus-like oomycetes. The eukaryotic copper-only SODs are particularly unique in that they lack an electrostatic loop for substrate guidance and have an unusual open-access copper site, yet they can still react with superoxide at rates limited only by diffusion. Copper-only SOD sequences similar to those seen in fungi and oomycetes are also found in the animal kingdom, but rather than single-domain enzymes, they appear as tandem repeats in large polypeptides we refer to as CSRPs (copper-only SOD-repeat proteins). Here, we compare and contrast the Cu,Zn copper-only SODs and discuss the evolution of copper-only SOD protein domains in animals and fungi.
Topics: Copper; Fungal Proteins; Fungi; Metalloproteins; Mycobacterium; Oomycetes; Periplasmic Proteins; Superoxide Dismutase; Zinc
PubMed: 29259135
DOI: 10.1074/jbc.TM117.000182 -
Journal of Diabetes Investigation Apr 2023The mechanisms underlying the effect of sodium-glucose cotransporter 2 (SGLT2) inhibitors on aortic endothelial dysfunction in diet-induced obesity are not clearly...
Luseogliflozin and caloric intake restriction increase superoxide dismutase 2 expression, promote antioxidative effects, and attenuate aortic endothelial dysfunction in diet-induced obese mice.
AIMS/INTRODUCTION
The mechanisms underlying the effect of sodium-glucose cotransporter 2 (SGLT2) inhibitors on aortic endothelial dysfunction in diet-induced obesity are not clearly understood. This study investigated whether SGLT2 inhibition by luseogliflozin improved free fatty acid (FFA)-induced endothelial dysfunction in high-fat diet (HFD)-induced obese mice.
MATERIALS AND METHODS
Mice were fed a control diet or high-fat diet for 8 weeks, and then each diet with or without luseogliflozin was provided for an additional 8 weeks under free or paired feeding. Afterward, the thoracic aortas were removed and utilized for the experiments.
RESULTS
Luseogliflozin treatment decreased body weight, fasting blood glucose, insulin, and total cholesterol in HFD-fed mice only under paired feeding but not under free feeding. Endothelial-dependent vasodilation under FFA exposure conditions was significantly lower in HFD-fed mice than in control diet-fed mice, and luseogliflozin treatment ameliorated FFA-induced endothelial dysfunction. Reactive oxygen species (ROS) production induced by FFA was significantly increased in HFD-induced obese mice. Luseogliflozin treatment increased the expression of superoxide dismutase 2 (SOD2), an antioxidative molecule, and reduced FFA-induced ROS production in the thoracic aorta. Superoxide dismutase reversed FFA-induced endothelial dysfunction in HFD-fed mice.
CONCLUSIONS
It was shown that caloric restriction is important for the effect of luseogliflozin on metabolic parameters and endothelial dysfunction. Furthermore, SGLT2 inhibition by luseogliflozin possibly ameliorates FFA-induced endothelial dysfunction by increasing SOD2 expression and decreasing reactive oxygen species production in the thoracic aorta.
Topics: Mice; Animals; Antioxidants; Reactive Oxygen Species; Sodium-Glucose Transporter 2; Mice, Obese; Caloric Restriction; Superoxide Dismutase; Aorta; Diet, High-Fat; Energy Intake; Vascular Diseases; Mice, Inbred C57BL
PubMed: 36729938
DOI: 10.1111/jdi.13981