Superoxide Dismutase Isoforms Research Articles

Protein expression patterns and metal metabolites in a protogynous hermaphrodite fish, the ricefield eel (Monopterus albus)

BackgroundThe ricefield eel Monopterus albus undergoes a natural sex change from female to male during its life cycle, and previous studies have shown the potential mechanisms of this transition at the transcriptional and protein levels. However, the changes in protein levels have not been fully explored, especially in the intersexual stage.ResultsIn the present study, the protein expression patterns in the gonadal tissues from five different periods, the ovary (OV), early intersexual stage gonad (IE), middle intersexual stage gonad (IM), late intersexual stage gonad (IL), and testis (TE), were determined by untargeted proteomics sequencing. A total of 5125 proteins and 394 differentially expressed proteins (DEPs) were detected in the gonadal tissues. Of the 394 DEPs, there were 136 between the OV and IE groups, 20 between the IM and IE groups, 179 between the IL and IM groups, and 59 between the TE and IL groups. Three candidate proteins, insulin-like growth factor 2 mRNA-binding protein 3 isoform X1 (Igf2bp3), triosephosphate isomerase (Tpi), and Cu-Zn superoxide dismutase isoform X1 [(Cu-Zn) Sod1], were validated by western blotting to verify the reliability of the data. Furthermore, metal metabolite-related proteins were enriched in the IL vs. IM groups and TE vs. IL groups, which had close relationships with sex change, including Cu2+-, Ca2+-, Zn2+- and Fe2+/Fe3+-related proteins. Analysis of the combined transcriptome data revealed consistent protein/mRNA expression trends for two metal metabolite-related proteins/genes [LOC109953912 and calcium Binding Protein 39 Like (cab39l)]. Notably, we detected significantly higher levels of Cu2+ during the sex change process, suggesting that Cu2+ is a male-related metal metabolite that may have an important function in male reproductive development.ConclusionsIn summary, we analyzed the protein profiles of ricefield eel gonadal tissues in five sexual stages (OV, IE, IM, IL, and TE) and verified the plausibility of the data. After preforming the functional enrichment of metal metabolite-related DEPs, we detected the contents of the metal metabolites Zn2+, Cu2+, Ca2+, and Fe2+/Fe3+ at these five stages and screened for (Cu-Zn) Sod1 and Mmp-9 as possible key proteins in the sex reversal process.

Context-dependent antioxidant defense system (ADS)-based stress memory in response to recurrent environmental challenges in congeneric invasive species

AbstractMarine ecosystems are facing escalating environmental fluctuations owing to climate change and human activities, imposing pressures on marine species. To withstand recurring environmental challenges, marine organisms, especially benthic species lacking behavioral choices to select optimal habitats, have to utilize well-established strategies such as the antioxidant defense system (ADS) to ensure their survival. Therefore, understanding of the mechanisms governing the ADS-based response is essential for gaining insights into adaptive strategies for managing environmental challenges. Here we conducted a comparative analysis of the physiological and transcriptional responses based on the ADS during two rounds of 'hypersalinity-recovery' challenges in two model congeneric invasive ascidians, Ciona robusta and C. savignyi. Our results demonstrated that C. savignyi exhibited higher tolerance and resistance to salinity stresses at the physiological level, while C. robusta demonstrated heightened responses at the transcriptional level. We observed distinct transcriptional responses, particularly in the utilization of two superoxide dismutase (SOD) isoforms. Both Ciona species developed physiological stress memory with elevated total SOD (T-SOD) and glutathione (GSH) responses, while only C. robusta demonstrated transcriptional stress memory. The regulatory distinctions within the Nrf2-Keap1 signalling pathway likely explain the formation disparity of transcriptional stress memory between both Ciona species. These findings support the 'context-dependent stress memory hypothesis', emphasizing the emergence of species-specific stress memory at diverse regulatory levels in response to recurrent environmental challenges. Our results enhance our understanding of the mechanisms of environmental challenge management in marine species, particularly those related to the ADS.

In silico identification and expression analysis of superoxide dismutases in Tenebrio molitor.

Insects encounter various environmental stresses, in response to which they generate reactive oxygen species (ROS). Superoxide dismutase (SOD) is an antioxidant metalloenzyme that scavenges superoxide radicals to prevent oxidative damage. To investigate expressions of SODs under oxidative stress in Tenebrio molitor. Here, we investigated the transcriptional expression of SODs by pesticide and heavy metals in Tenebrio moltior. First, we searched an RNA-Seq database for T. molitor SOD (TmSOD) genes and identified two SOD isoforms (TmSOD1-iso1 and iso2). We examined their activities under developmental stage, tissue-specific, and various types (pesticide and heavy metal) of oxidative stress by using qPCR. Our results revealed two novel forms of TmSODs. These TmSODs had a copper/zinc superoxide dismutase domain, active site, Cu2+ binding site, Zn2+ binding site, E-class dimer interface, and P-class dimer interface. TmSODs (TmSOD1-iso1 and iso2) were expressed in diverse developmental phases and tissues. Pesticides and heavy metals caused an upregulation of these TmSODs. Our findings suggest that the two TmSODs have different functions in T. molitor, providing insights into the detoxification ability of T. molitor.

Enantioselective biomarkers of maize toxicity induced by hexabromocyclododecane based on submicroscopic structure, gene expression and molecular docking

Hexabromocyclododecane (HBCD), as a monitored chemical of the Chemical Weapons Convention, the Stockholm Convention and the Action Plan for New Pollutants Treatment in China, raises significant concerns on its impact of human health and food security. This study investigated enantiomer-specific biomarkers of HBCD in maize (Zea mays L.). Upon exposure to HBCD enantiomers, the maize root tip cell wall exhibited thinning, uneven cell gaps, and increased deposition on the cell outer wall. Elevated malondialdehyde (MDA) indicated lipid peroxidation, with higher mitochondrial membrane potential (MMP) inhibition in (+)-enantiomer treatments (47.2%–57.9%) than (−)-enantiomers (14.4%–37.4%). The cell death rate significantly increased by 37.7%–108.8% in roots and 16.4%–62.4% in shoots, accompanied by the upregulation of superoxide dismutase isoforms genes. Molecular docking presenting interactions between HBCD and target proteins, suggested that HBCD has an affinity for antioxidant enzyme receptors with higher binding energy for (+)-enantiomers, further confirming their stronger toxic effects. All indicators revealed that oxidative damage to maize seedlings was more severe after treatment with (+)-enantiomers compared to (−)-enantiomers. This study elucidates the biomarkers of phytotoxicity evolution induced by HBCD enantiomers, providing valuable insights for the formulation of more effective policies to safeguard environmental safety and human health in the future.

Variation in oxidative defense system and physiological traits in Maize under drought stress

The study included the role of key metabolites involved in oxidative defense, and osmotic adjustment under water stress is still undiscovered. We have evaluated whether antioxidant potential could be nominated as a potential marker of drought resistance in three maize hybrids (SC01, SC703, and SC720). Underwater deficiency in all maize hybrids decreased significantly compared to control samples in grain yield, photosynthetic pigments, and phenolic compounds. In contrast, proline and glycine betaine (GB) significantly increased. In contrast, a significant increase (p<?0.05) was detected in the lipid peroxidation indicator of malondialdehyde (MDA). The hydrogen peroxide (H2O2) and total soluble proteins remained unaffected under drought stress in the three maize hybrids. Electrophoretic investigations attributed three, two, and one isoforms, respectively, to peroxidase (POX), superoxide dismutase (SOD), and catalase (CAT). In the studied maize hybrids, SOD isoforms, including Fe-SOD, Cu/Zn-SOD, and Mn-SOD, appeared on the 8% slab polyacrylamide gels. The water stress decreases Mn-SOD, Cu/Zn-SOD, and Fe-SOD activities in all three hybrids. Further, POX1, POX2, and CAT activities decreased in SC01 and SC703, while they increased in SC720 under water deficit stress. In all maize hybrids, oxidative stress from water limitation leads to significant changes in the enzymatic/non-enzymatic antioxidants and main organic osmolytes. Based on the current study's findings, we believe that Cu/Zn-SOD activity, proline, and photosynthetic pigments might be used as biochemical indicators of water stress tolerance.

Evaluation of the tolerance and accumulation potential of selected sunflower hybrids grown in soil contaminated with cadmium

Common sunflower (Helianthus annuus L.) belongs to the group of crops with high biomass and high capacity for the accumulation of various metals. Previous studies have suggested that remedial potential is strongly determined by genotype. In our study, we evaluated the tolerance of six sunflower hybrids (P64HE118, P64LE136, P62LE122, P64HE133, P64HE144 and P63LP25) to cadmium ions (Cd 100 mg kg−1 soil), and we also evaluated their remediation potential. All tested hybrids showed high tolerance to Cd, no significant changes were noted with regard to growth, content of photosynthetic pigments, leaf area, water content, proline content, or accumulation of superoxide dismutase (SOD) isoforms. We noted an increased rate of membrane lipid peroxidation for P64HE118, P64LE136 and P64HE144 hybrids. The increased content of glutathione in the leaves of P64HE118 and P64LE136 hybrids indicates this molecule's involvement in the Cd detoxification process. All hybrids accumulated Cd preferentially in the roots. The most Cd was accumulated in the roots and shoots of hybrid P64HE118. Values of bioaccumulation factor and translocation factor were hybrid-dependent, being generally higher for standard/control soil (Cd 1.2 mg kg−1 soil). Better phytoremediation potential of these hybrids can hence be expected at lower Cd doses in the soil. The high tolerance of tested hybrids to a higher dose and the non-negligible accumulation of Cd in roots also supports using these hybrids in soil phytostabilisation.

Comparison effect of high-intensity interval training and moderate intensity continuous training on vascular function in a mouse model of lower extremity peripheral artery disease

Introduction
 Lower extremity peripheral artery disease (PAD), due to narrowing of the arteries supplying the legs, represents a major cause of physical disability. Exercise training is an important part of PAD treatment, improving functional capacity. Recent research suggests that exercise training-induced endothelial function improvement is involved in the benefits of exercise in PAD (Lee et al., 2023); however, the underlying molecular mechanisms remain unknown. In addition, the potential vascular benefits of high intensity training in PAD remain unexplored. Therefore, the aim of the study was to compare the effects of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) on endurance capacity, vascular endothelial function and expression of genes related to nitric oxide (NO) bioavailability in a mouse model of PAD.
 Methods
 PAD disease model was generated in male C57BL/6 mice by ligation of the right iliac artery. Mice with PAD were divided into 3 groups: sedentary control group (SED), MICT (40 min running at 70% of maximal aerobic speed) and HIIT (8 intervals of 2.5 minutes running at 90% of maximal aerobic speed combined with 2.5 minutes of running at 50% of maximal aerobic speed). Mice were exercised three times per week for 8 weeks. Maximal running time was determined by an incremental test until exhaustion. Vascular reactivity was assessed by measuring vasoconstrictor responses to phenylephrine as well as endothelium-dependent and -independent vasodilator responses to acetylcholine and DEA-NONOate, respectively, in isolated aortic rings. Gene expression of antioxidant enzymes (catalase and superoxide dismutase isoforms), prooxidant NADPH oxidase subunits (p22phox and p47phox), enzyme involved in NO production (endothelial NO synthase), vascular smooth muscle cell relaxation (soluble guanylate cyclase) and receptors involved in vascular tone regulation (a1 and b2 adrenergic receptors) was determined in aortic tissue by qPCR.
 Results
 Maximal running time was improved in both MICT and HIIT as compared to SED at the end of the study, but with no significant difference between the two exercise groups. Phenylephrine-induced vasoconstriction as well as vasodilator responses to acetylcholine and DEA-NONOate were significantly improved in MICT compared to SED while no significant differences were reported between HIIT and SED. There was no significant difference in gene expression among the three groups.
 Discussion/Conclusion
 MICT and HIIT were equally effective at improving endurance capacity in mice with PAD. However, only MICT improved vascular reactivity.
 References
 Lee, J., Zarezadehmehrizi, A., LaVoy, E., Markofski, M., & Park, Y. (2023). Exercise training improves brachial artery endothelial function, but does not alter inflammatory biomarkers in patients with peripheral artery disease: A systematic review and meta-analysis. Journal of Cardiovascular Translational Research. Advance online publication. https://doi.org/10.1007/s12265-023-10451-0

Yellow fever virus infection in human hepatocyte cells triggers an imbalance in redox homeostasis with increased reactive oxygen species production, oxidative stress, and decreased antioxidant enzymes

Yellow fever (YF) presents a wide spectrum of severity, with clinical manifestations in humans ranging from febrile and self-limited to fatal cases. Although YF is an old disease for which an effective and safe vaccine exists, little is known about the viral- and host-specific mechanisms that contribute to liver pathology. Several studies have demonstrated that oxidative stress triggered by viral infections contributes to pathogenesis. We evaluated whether yellow fever virus (YFV), when infecting human hepatocytes cells, could trigger an imbalance in redox homeostasis, culminating in oxidative stress. YFV infection resulted in a significant increase in reactive oxygen species (ROS) levels from 2 to 4 days post infection (dpi). When measuring oxidative parameters at 4 dpi, YFV infection caused oxidative damage to lipids, proteins, and DNA, evidenced by an increase in lipid peroxidation/8-isoprostane, carbonyl protein, and 8-hydroxy-2′-deoxyguanosine, respectively. Furthermore, there was a significant reduction in the activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), in addition to a reduction in the ratio of reduced to oxidized glutathione (GSH/GSSG), indicating a pro-oxidant environment. However, no changes were observed in the enzymatic activity of the enzyme catalase (CAT) or in the gene expression of SOD isoforms (1/2/3), CAT, or GPx. Therefore, our results show that YFV infection generates an imbalance in redox homeostasis, with the overproduction of ROS and depletion of antioxidant enzymes, which induces oxidative damage to cellular constituents. Moreover, as it has been demonstrated that oxidative stress is a conspicuous event in YFV infection, therapeutic strategies based on antioxidant biopharmaceuticals may be new targets for the treatment of YF.

Identification of Superoxide Dismutase (SOD) Isozymes in Plant Tissues.

Superoxide and hydrogen peroxide are reactive oxygen species (ROS) involved in the oxidation of multiple biological molecules and the signaling processes during plant growth and stress response. Thus, control of ROS is fundamental for cell survival and development, with superoxide dismutase (EC 1.15.1.1, SOD) being one of the main enzymes involved. Different isoforms of SOD catalyze the dismutation of superoxide (O2.-) to hydrogen peroxide (H2O2) and oxygen (O2), such as Mn-SODs, Cu,Zn-SODs, and Fe-SODs. Using non-denaturing polyacrylamide gel electrophoresis (PAGE) combined with a specific staining method for SOD activity, the protocol describes the identification of different SOD isozymes, based on their differential inhibition by KCN and H2O2, in different organs and plant species such as pea (Pisum sativum L.) leaves and pepper (Capsicum annuum L.) fruits.

Liver Oxidative Status, Serum Lipids Levels after Bariatric Surgery and High-Fat, High-Sugar Diet in Animal Model of Induced Obesity.

Nutritional status is a major determinant of hepatocyte injuries associated with changed metabolism and oxidative stress. This study aimed to determine the relations between oxidative stress, bariatric surgery, and a high-fat/high-sugar (HFS) diet in a diet-induced obesity rat model. Male rats were maintained on a control diet (CD) or high-fat/high-sugar diet (HFS) inducing obesity. After 8 weeks, the animals underwent SHAM (n = 14) or DJOS (n = 14) surgery and the diet was either changed or unchanged. Eight weeks after the surgeries, the activity of superoxide dismutase isoforms (total SOD, MnSOD, and CuZnSOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and lutathione S-transferase, as well as the thiol groups (-SH) concentration, total antioxidant capacity (TAC), total oxidative stress (TOS) levels, and malondialdehyde (MDA) concentration liver tissue were assessed. The total cholesterol, triglycerides (TG), and high-density lipoprotein (HDL) concentrations were measured in the serum. The total SOD and GPX activities were higher in the SHAM-operated rats than in the DJOS-operated rats. The MnSOD activity was higher in the HFS/HFS than the CD/CD groups. Higher CuZnSOD, GST, GR activities, -SH, and MDA concentrations in the liver, and the triglyceride and cholesterol concentrations in the serum were observed in the SHAM-operated rats than in the DJOS-operated rats. The CAT activity was significantly higher in the HFS-fed rats. Lower TAC and higher TOS values were observed in the SHAM-operated rats. Unhealthy habits after bariatric surgery may be responsible for treatment failure and establishing an obesity condition with increased oxidative stress.

Antioxidant enzymes of Pseudochlorella pringsheimii under two stressors: variation of SOD Isoforms activity

Algae are always facing the challenge of exposure to different stress conditions, therefore raising challenges of adaptation for survival. In this context, the growth and the antioxidant enzymes of the green stress-tolerant alga Pseudochlorella pringsheimii were investigated under two environmental stresses viz. iron and salinity. The number of algal cells was moderately increased by iron treatment in the range of 0.025–0.09 mM of iron, yet, the number of cells decreased at high iron concentrations (0.18 to 0.7 mM Fe). Furthermore, the different NaCl concentrations (8.5–136.0 mM) had an inhibitory effect on the algal cell number, compared to the control.The superoxide dismutase (SOD) showed three isoforms namely; Mn, Fe, and Cu/Zn SOD. The in gel and in vitro (tube-test) activities of FeSOD were higher compared with the other SOD isoforms. The activity of total SOD and its isoforms increased significantly by the different concentrations of Fe and non-significantly by NaCl. The maximum SOD activity was recorded at 0.7 mM Fe (67.9% above control). The relative expression of FeSOD was high under iron and NaCl at 8.5 and 34 mM, respectively. However, FeSOD expression was reduced at the highest NaCl tested concentration (136 mM). In addition, the antioxidant enzyme activity of catalase (CAT) and peroxidase (POD) were accelerated by increasing iron and salinity stress which indicates the essential role of these enzymes under stress. The correlation between the investigated parameters was also investigated. A highly significant positive correlation between the activity of total SOD and its isoforms, and with the relative expression of FeSOD was observed.

Effects of different dietary carbohydrate-to-protein ratios on the growth performance, antioxidant capacity and energy metabolism in Marsupenaeus japonicus

Four diets containing different carbohydrate-to-protein ratios including the control (18% carbohydrate, 45.98% protein), 0.51 C/P (22% carbohydrate, 43.55% protein), 0.58 C/P (24% carbohydrate, 42.33% protein) and 0.72 C/P (28% carbohydrate, 38.91% protein) were designed to investigate the effects of dietary carbohydrate-to-protein ratios (C/P) on the growth performance, antioxidant capacity and energy metabolism in Marsupenaeus japonicus. Totals of 300 shrimp with an average initial weight of 1.08 ± 0.01 g were randomly assigned to four different dietary treatments. Each treatment included three 300 L tanks, with 25 shrimp in each tank. The results indicated that although growth performance had a decreased trend with increased carbohydrate-to-protein ratios, no overall difference (P > 0.05) was observed. There was a significant decreased trend (P < 0.05) in the acitivity of serum superoxide dismutase (SOD) and glutathione peroxidase (GSH) with the increased carbohydrate-to-protein ratios. It’s worthy noting that inter-tissue differences existed in the antioxidant capacity of M.japonicus in response to dietary different carbohydrate-to-protein ratios. The expression of the antioxidant genes (superoxide dismutase isoform 5, sod-5; peroxiredoxin, prx; ferriten) and heat shock protein 70 in intestine was up-regulated (approximately 20–250 fold) (P < 0.05), while the expression of antioxidant genes (sod-5, prx, ferriten) in hepatopancreas was lowered (P < 0.05) with the dietary increased carbohydrate-to-protein ratios. With the dietary increased carbohydrate-to-protein ratios, energy metabolism genes were up-regulated (P < 0.05) while the pepck1 level was down-regulated (P < 0.05) in the hepatopancreas. In addition, there was a first increased and then decreased trend (P < 0.05) of energy metabolism associated gene expressions in intestine. When shrimp fed with 0.72 C/P diet, although above energy metabolism associated genes expression except pepck1 showed a downward trend, its value was still significantly higher (P < 0.05) compared with the control group. In conclusion, although growth performance was not significantly influenced by different carbohydrate-to-protein ratios, antioxidant capacity and energy metabolism was affected in M.japonicus. The response mechanism to different carbohydrate-to-protein ratios showed tissue-specific. Hepatopancreas and intestine were collaborative to regulate antioxidant and energy metabolism in M.japonicus.

CONSUMPTION OF BROCCOLI SPROUTS INCREASED THE ACTIVITY OF GLUTATHIONE-DEPENDENT ANTIOXIDANT ENZYMES IN MURINE LIVER

Aim. The purpose of this work was to investigate effects of the consumption of broccoli sprouts on the activity of antioxidant defense enzymes in the liver of. GPx isoforms. After photo fixation of gels, we determined activity of each isoform densitometrically using ImageJ software. Results were statistically analyzed by ANOVA followed by post-hoc Tukey's test. Data are presented as mean±SEM. Methods. Frozen tissue was homozeniged in lysis buffer, centrifuged and resulted supernatants were used for analysis. Activities of enzymes were determined by using electrophoresis in polyacrylamide gel. After electrophoresis we conducted dyeing of separate gels for detection of superoxide dismutase (SOD), glutathione-S-transferase (GST) or glutathione peroxidase (GPx) isoforms. After photo fixation of gels, we determined activity of each isoform densitometrically using ImageJ software. Results were statistically analyzed by ANOVA followed by post-hoc Tukey's test. Data are presented as mean±SEM. Results. In the hepatic tissue of all four groups of mice, two isoforms of SOD (SOD1 and SOD2) were detected in gels. The intensity of the bands of both isoforms was not significantly different between groups. Three isoforms of GST (GST1, GST2, GST3) were detected in the liver samples. The activity of GST1 did not significantly differ between the experimental groups. Activities of GST2 and GST3 forms were significantly higher in the group “Broccoli” compared to Control and Cafeteria Diet groups. We identified three isoforms of glutathione peroxidase (GPx1, GPx2, GPx3) in liver samples. The activity of GPx isoform 1 was not significantly different between the experimental groups. The activity of GPx2 was significantly higher in the group of mice that consumed Broccoli and Cafeteria Diet + Broccoli compared to Control. GPx2 activity was significantly higher in the Broccoli group compared to the Cafeteria Diet group. Activity of GPx3 was significantly higher in the Broccoli group compared to the Control and Cafeteria Diet group. Conclusions. Cafeteria diet did not significantly affect the activity of SOD isoforms, but led to redistribution of in the activity of GST and GPx isoforms in murine liver. Feeding with broccoli spouts significantly increased the activity of 2 and 3 isoforms of GST and GPx in murine liver compared to values in control mice and mice fed with cafeteria diet. Combination of Broccoli + Cafereria diet had small activating effects on antioxidant enzyme acivity, compared with cafeteria diet.

Promising role of selenium in mitigating the negative effects of iron deficiency in soybean leaves

Little is known about the role of selenium (Se) in modulating the nutritional status and the non-enzymatic and enzymatic antioxidant defense system in iron(Fe)-deficient soybean. Hence, this work aimed to evaluate the possible beneficial effect of Se applied in the nutrient solution on photosynthetic pigments, nutritional status, reactive oxygen species accumulation, ascorbate and glutathione metabolites, activity of enzymes involved in the synthesis pathway of these metabolites, and antioxidant defense enzymes, including expression of superoxide dismutase (SOD) isoforms, after exposure to absence, deficiency, and sufficiency of Fe in combination with absence and presence of Se. The experimental design was completely randomized with 5 replications, containing 4 plants per pot. In this work, through physiological, biochemical, and molecular analyses, we observed a beneficial effect of Se in soybean plants with Fe suppression, mainly in the absence of Fe. Thus, in the absence of Fe with Se, there was higher remobilization of Fe and maintenance of foliar N concentration, which resulted in mitigation of leaf chlorosis and decreased loss of photosynthetic pigments. Additionally, under this cultivation condition, the main positive effect of Se was shown to be associated with the modulation of the glutathione cycle, with increases in the reduced glutathione and total glutathione content, reduced glutathione/oxidized glutathione ratio, and in the activity of the γ-glutamylcysteine synthetase, glutathione peroxidase, and glutathione reductase enzymes. The Se supply also reduced the need to replace SOD-Fe with SOD-Cu due to the positive modulation in the crosstalk between Fe and Cu, as well as attenuated the nutritional imbalance of Zn and Mn, mainly in the absence of Fe. These adjustments prevented lipid peroxidation and showed the beneficial role of Se in Fe-depleted plants.

SOD2 in platelets: with age comes responsibility

SOD2 in platelets: with age comes responsibility

Comparative transcriptomics reveals the immune dynamics during the molting cycle of swimming crab Portunus trituberculatus.

Molting is one of the most important biological processes of crustacean species, and a number of molecular mechanisms facilitate this complex procedure. However, the understanding of the immune mechanisms underlying crustacean molting cycle remains very limited. This study performed transcriptome sequencing in hemolymph and hepatopancreas of the swimming crab (Portunus trituberculatus) during the four molting stages: post-molt (AB), inter-molt (C), pre-molt (D), and ecdysis (E). The results showed that there were 78,572 unigenes that were obtained in the hemolymph and hepatopancreas of P. trituberculatus. Further analysis showed that 98 DEGs were involved in immunity response of hemolymph and hepatopancreas, and most of the DEGs participated in the process of signal transduction, pattern recognition proteins/receptors, and antioxidative enzymes system. Specifically, the key genes and pathway involved in signal transduction including the GPCR126, beta-integrin, integrin, three genes in mitogen-activated protein kinase (MAPK) signaling cascade (MAPKKK10, MAPKK4, and p38 MAPK), and four genes in Toll pathway (Toll-like receptor, cactus, pelle-like kinase, and NFIL3). For the pattern recognition proteins/receptors, the lowest expression level of 11 genes was found in the E stage, including C-type lectin receptor, C-type lectin domain family 6 member A and SRB3/C in the hemolymph, and hepatopancreatic lectin 4, C-type lectin, SRB, Down syndrome cell adhesion molecule homolog, Down syndrome cell adhesion molecule isoform, and A2M. Moreover, the expression level of copper/zinc superoxide dismutase isoform 4, glutathione peroxidase, glutathione S-transferase, peroxiredoxin, peroxiredoxin 6, and dual oxidase 2 in stage C or stage D significantly higher than that of stage E or stage AB. These results fill in the gap of the continuous transcriptional changes that are evident during the molting cycle of crab and further provided valuable information for elucidating the molecular mechanisms of immune regulation during the molting cycle of crab.

Protein Phosphorylation and Redox Status: An as Yet Elusive Dyad in Chronic Lymphocytic Leukemia.

Simple SummaryPhosphorylation is one of the most crucial modifications of lipids and proteins, as it regulates virtually all cellular functions. Like other human diseases, chronic lymphocytic leukemia (CLL), the most common leukemia in Western developed countries, exhibits deranged phosphorylation, which is induced by stimuli within specific tissues (e.g., lymph nodes), promoting enhanced proliferation and survival. Importantly, a growing body of evidence shows that reactive oxygen species (ROS), altered forms of oxygens generated from metabolism and peculiar enzyme complexes, and generally considered highly harmful due to their reactivity toward critical biomolecules (proteins, lipids, and DNA), act in concert with phosphorylation in supporting the malignant phenotype in CLL. This complex interplay is now providing insights into potential novel Achilles heels of intracellular signals for the development of innovative treatments which might synergize with the drugs currently in use that target the principal players in phosphorylation, namely kinases.Malignant cells in chronic lymphocytic leukemia (CLL) are characterized by oxidative stress that is related to abundant generation of reactive oxygen species (ROS) by increased mitochondrial oxidative phosphorylation (OXPHOS). Lymphoid tissues have been shown to provide a protective microenvironment that antagonizes the effects of ROS, contributing to establishing redox homeostasis that supports the vitality of CLL cells. In the last few decades, a complex antioxidant machinery has been demonstrated to be activated in CLL cells, including the different superoxide dismutase (SOD) isoforms, the thioredoxin (Trx) system, and the enzyme cascade inducing glutathione (GSH) biosynthesis and recycling, to name a few. Their expression is known to be upregulated by the activation of specific transcription factors, which can be regulated by either oxidative stress or phosphorylation. These two latter aspects have mostly been explored separately, and only recently an increasing body of evidence has been providing reasonable inference that ROS and phosphorylation may cooperate in an interplay that contributes to the survival mechanisms of CLL cells. Here, we present an overview of how oxidative stress and phosphorylation-dependent signals are intertwined in CLL, focusing on transcription factors that regulate the balance between ROS production and scavenging.

Distribution and diversity of ROS-generating enzymes across the animal kingdom, with a focus on sponges (Porifera)

BackgroundReactive derivatives of oxygen (reactive oxygen species; ROS) are essential in signalling networks of all aerobic life. Redox signalling, based on cascades of oxidation–reduction reactions, is an evolutionarily ancient mechanism that uses ROS to regulate an array of vital cellular processes. Hydrogen peroxide (H2O2) and superoxide anion (O2•−) are employed as signalling molecules that alter the oxidation state of atoms, inhibiting or activating gene activity. Here, we conduct metazoan-wide comparative genomic assessments of the two enzyme families, superoxide dismutase (SOD) and NADPH oxidases (NOX), that generate H2O2 and/or O2•− in animals.ResultsUsing the genomes of 19 metazoan species representing 10 phyla, we expand significantly on previous surveys of these two ancient enzyme families. We find that the diversity and distribution of both the SOD and NOX enzyme families comprise some conserved members but also vary considerably across phyletic animal lineages. For example, there is substantial NOX gene loss in the ctenophore Mnemiopsis leidyi and divergent SOD isoforms in the bilaterians D. melanogaster and C. elegans. We focus particularly on the sponges (phylum Porifera), a sister group to all other metazoans, from which these enzymes have not previously been described. Within Porifera, we find a unique calcium-regulated NOX, the widespread radiation of an atypical member of CuZnSOD named Rsod, and a novel endoplasmic reticulum MnSOD that is prevalent across aquatic metazoans.ConclusionsConsidering the precise, spatiotemporal specificity of redox signalling, our findings highlight the value of expanding redox research across a greater diversity of organisms to better understand the functional roles of these ancient enzymes within a universally important signalling mechanism.

Altered Expression of Superoxid Dismutase (SOD) Isoforms Is Necesary For Better Performance of A Recently Developed Drought-Tolerant Mutant of Rice Under Dehydration Stress

Drought is one of the most important abiotic stresses, which annually reduces agriculture production worldwide. With regard to the occurrence of successive drought stress in the life period of crop plants, dealing with the stress, particularly in rice growing regions needs special attention. Therefore, this study aimed to investigate and to compare a recently-developed drought-tolerant mutant line under dehydration stress with its original parental cultivar (Neda). Mutant line performed better than its original parental cultivar Neda at seedling and whole plant stages under dehydration and drought stresses, respectively. For gene expression analysis, dehydration stress was mimicked by polyethylene glycol 6000 (osmotic pressure of -6 bar), and sampling was done at 0, 12, 24 and 36 hours after the stress, and expression of two isoforms of superoxide dismutase (SOD) gene was evaluated by real-time quantitative PCR method. Assessment of relative expression of superoxide dismutase isoform OsMnSOD at different times after stress showed that the expression of this gene in the parental cultivar was not significantly altered after the stress, while in the mutant line MT149 it was significantly decreased within early hours after stress but was significantly increased up to 11-fold within 24 hours after stress, and the expression of another isoform of superoxide dismutase, OsCu-ZnSOD, in mutant line MT149 also was first decreased and then increased up to 9-fold within 24 hours after stress. On the basis of the results of this research it can be concluded that probably one of the reasons for higher drought/dehydration tolerance of the mutant MT149 compared to Neda, is the increased expression of both isoforms of OsMnSOD and OsCu-ZnSOD within first 24 hours of exposing to the stress, making it possible to overcome the toxic effects of reactive oxygen species (ROS).

Soybean roots defence against cadmium and its dependence on dose in a non-linear manner

Abstract Metal pollution represents a serious issue for sustainable agronomy and food safety. Activation of plants’ protective mechanisms has been shown to depend on the extent of soil contamination with metal, but reports on dose-dependent responses (especially to extreme concentrations) are rather rare. In this research we exposed soybean (Glycine max L.) roots at a very early stage to a scale of cadmium concentrations, including doses far exceeding the amounts found in nature. Spectrophotometrical and enzyme in-gel detection assays were used to examine ongoing defence responses. The results confirmed commonly reported findings on inhibited growth and the activation of several superoxide dismutase isoforms in a dose-dependent manner. Contrary to expectations, the hydrogen peroxide levels, proline accumulation and the rate of lipid peroxidation were suppressed with increasing metal doses. More importantly, the linearity of Cd accumulation in soybean roots was interrupted at 200 mg.l-1 of cadmium, which coincides with peculiar responses of several chitinase family members. No such nonlinear response was observable for proline accumulation or any of the SOD isoforms. Possible explanations are provided and the importance of considering the metal stress dose is stressed to avoid false generalizations on plant defence responses.