Manganese-containing Superoxide Dismutase Research Articles

Antifungal Activity, Synergism with Fluconazole or Amphotericin B and Potential Mechanism of Direct Current against Candida albicans Biofilms and Persisters.

Candida albicans, as a notorious fungal pathogen, is associated with high morbidity and mortality worldwide due to its ability to form biofilms and persisters that can withstand currently available antifungals. Direct current (DC) has demonstrated a promising antimicrobial effect and synergistic effect with antimicrobials against various infections. Here, we first found DC exerted a killing effect on C. albicans planktonic and biofilm cells. Moreover, DC showed a synergistic effect with fluconazole (FLC) and amphotericin B (AMB). Notably, near-to-complete eradication of AMB-tolerant C. albicans biofilm persisters was achieved upon DC treatment. Next, the mechanism of action of DC was explored through mapping the genes and proteomic profiles of DC-treated C. albicans. The multi-omics analysis, quantitative real-time PCR and assay of reactive oxygen species (ROS) demonstrated DC exerted an antifungal effect on C. albicans by increasing cellular oxidative stress. As revealed by multiple analyses (e.g., protein assay based on absorbance at 280 nm and rhodamine 6G assay), DC was able to enhance membrane permeability, inhibit drug efflux and increase cellular FLC/AMB concentration of C. albicans, thereby mediating its synergism with the antifungals. Furthermore, DC inhibited superoxide dismutase 2 (SOD2) expression and manganese-containing SOD (Mn SOD) activity, leading to ROS production and enhanced killing of C. albicans biofilm persisters. The current findings demonstrate that the adjunctive use of DC in combination with antifungals is a promising strategy for effective control of C. albicans infections and management of antifungal resistance/tolerance in Candida biofilms.

Artemisia argyi extract exerts antioxidant properties and extends the lifespan of Drosophila melanogaster.

Chinese mugwort (Artemisia argyi) possesses extensive pharmacological activities associated with anti-tumour, antioxidative and anti-inflammatory effects. The present study aimed to investigate the antioxidant and anti-ageing effects of A. argyi extract (AAE) on the fruit fly (Drosophila melanogaster) ageing model by detecting antioxidant enzyme activities and the mRNA level of antioxidant genes. AAE could significantly lengthen the mean lifespan, 50% survival days, and maximum lifespan of D. melanogaster, especially when the amount of AAE added reached 6.68 mg mL-1, the mean lifespan of both female and male flies increased by 23.74% and 22.30%, respectively, indicating the effective life extension effect of AAE. At the same time, AAE could improve the climbing ability and tolerance to hydrogen peroxide in D. melanogaster. In addition, the addition of AAE effectively increased the activities of copper-zinc-containing superoxide dismutase, manganese-containing superoxide dismutase and catalase in D. melanogaster and reduced the contents of malondialdehyde. Moreover, when reared with diets containing AAE, the expression of antioxidant-related genes SOD1, SOD2 and CAT was up-regulated in D. melanogaster and down-regulated for MTH genes. The study indicates that AAE effectively enhances the antioxidant capacity of D. melanogaster and has potential applications as an antioxidant and anti-ageing agent in the nutraceutical industry. © 2024 Society of Chemical Industry.

Klotho, Oxidative Stress, and Mitochondrial Damage in Kidney Disease.

Reducing oxidative stress stands at the center of a prevention and control strategy for mitigating cellular senescence and aging. Kidney disease is characterized by a premature aging syndrome, and to find a modulator targeting against oxidative stress, mitochondrial dysfunction, and cellular senescence in kidney cells could be of great significance to prevent and control the progression of this disease. This review focuses on the pathogenic mechanisms related to the appearance of oxidative stress damage and mitochondrial dysfunction in kidney disease. In this scenario, the anti-aging Klotho protein plays a crucial role by modulating signaling pathways involving the manganese-containing superoxide dismutase (Mn-SOD) and the transcription factors FoxO and Nrf2, known antioxidant systems, and other known mitochondrial function regulators, such as mitochondrial uncoupling protein 1 (UCP1), B-cell lymphoma-2 (BCL-2), Wnt/β-catenin, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1 alpha), transcription factor EB, (TFEB), and peroxisome proliferator-activated receptor gamma (PPAR-gamma). Therefore, Klotho is postulated as a very promising new target for future therapeutic strategies against oxidative stress, mitochondria abnormalities, and cellular senescence in kidney disease patients.

Mn-SOD alleviates methotrexate-related hepatocellular injury via GSK-3β affecting anti-oxidative stress of HO-1 and Drp1.

Methotrexate (MTX) is the most common therapeutic agent that may have the risk of drug-induced liver injury. Its pathogenic mechanism is related to oxidative stress caused by mitochondrial dysfunction. Superoxide dismutase (SOD), including manganese-containing SOD (Mn-SOD), can exert its effect of anti-oxidative stress by scavenging superoxide free radicals. Accordingly, this study is performed to explore the underlying molecular mechanism via observing whether Mn-SOD could affect the damage of MTX to hepatocytes. Human hepatocyte cell line L-02 was cultured in vitro and divided into 4 groups, including a blank group with the addition of the same volume of serum-free medium, a MTX group (40 μg/well MTX drug-treatment), a MTX+NC group (40 μg/well MTX drug-treatment+blank plasmid), and a MTX+SOD group (40 μg/well MTX drug-treatment+Mn-SOD plasmid). The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and microRNA-122 (miR-122) in the supernatant of cell culture were respectively detected by automatic biochemical analytical instrument and real-time RT-PCR to evaluate the degree of hepatocyte damage in each group. MitoSOX fluorescent probe was used to label intracellular superoxide in each group, and cell apoptosis was detected by flow cytometry. Meanwhile, the contents of glycogen synthase kinase-3 beta (GSK-3β), hemeoxygenase-1 (HO-1), mitochondrial fission-mediated protein of dynamin-related protein 1 (Drp1), and Mn-SOD were detected by Western blotting. Compared with the blank group, the levels of ALT, AST, and miR-122 in the supernatant of hepatocyte culture of the MTX group and MTX+NC group were significantly elevated (all P <0.05), and that in the MTX+SOD group were significantly decreased ( P <0.05) and equivalent to that in the blank group. MitoSOX staining revealed that the MTX group and MTX+NC had the most abundant superoxide; and the amount was significantly reduced in the MTX+SOD group, without a significant difference when compared with the blank group. Furthermore, the results of flow cytometry indicated that compared with the blank group, the MTX group and MTX+NC group showed significantly increased cell apoptosis ( P <0.05); while there was obviously reduced cell apoptosis in the MTX+SOD group than that in the MTX group and MTX+NC group ( P <0.05). According to the results of Western blotting, the blank group and MTX+SOD group had higher expressions of Mn-SOD, p-GSK-3β, and HO-1; while the MTX group and MTX+NC group exhibited remarkably lower levels of Mn-SOD, p-GSK-3β, and HO-1 than those in the blank group ( P <0.05). Besides, a completely opposite trend was found in the expression of Drp1, which was highly expressed in the MTX group and MTX+NC group, but lowly expressed in the blank group and the MTX+SOD group. MTX may induce hepatocyte damage, and one of the mechanisms may be due to the decrease of intracellular Mn-SOD level, which can cause the accumulation of superoxide, affect the levels of HO-1 and Drp1 through GSK-3β leading to mitochondrial damage and cell apoptosis. High expression of Mn-SOD intracellularly through exogenous introduction can scavenge drug-produced superoxide, affect HO-1 and Drp1 levels through GSK-3β, activate mitochondria, protect cells against damage from oxidative stress, and inhibit hepatocyte apoptosis eventually. So exogenous introduction of SOD may be a potential therapeutic approach to block or reverse MTX-related hepatocyte injury.

Prediction injury of the central nervous system in the neonatal period in preterm newborns

Objective: to develop a system for predicting the probability of developing damage of the central nervoussystem (CNS) in the neonatal period in children who was born prematurely. Materials and methods: the main group of the study is premature newborns with gestational age (GA) less than 36 weeks inclusive (n = 60), the control group – fullterm newborns (n = 35). In the process of dynamic observation, the main group was divided into subgroups depending on the diagnosed CNS injury in the neonatal period, according to the neurosonography (intraventricular hemorrhages (IVH), periventricular leukomalacia (PVL): subgroup 1 (prematurity babies with CNS injury) – 25 people, subgroup 2 (premature babies without CNS injury) – 35 people. we estimated clinical and anamnestic, laboratory and instrumental data of children at birth and in dynamics, indicators of antioxidant protection (manganese-containing superoxide dismutase (Mn-SOD), copper, zinc-containing superoxide dismutase (Cu, Zn-SOD), reduced glutathione (GSH), oxidized glutathione (GSSG), total antioxidant capacity of blood (TAS/TAC), oxidative stress (TOS/TOC), 4 polymorphisms of Mn-SOD gene. Results: we designed two prognostic models which can determine the probability of developing IVH and PVL in the neonatal period in premature newborns. This models are included GA, Apgar scores at 1 and 5 minutes of life, presence of respiratory failure at birth, invasive mechanical ventilation in the neonatal period, presence of intrauterine infection in the neonatal period and indicators of antioxidant protection (GSH, TAS/TAC; model 2). Conclusions: a comprehensive assessment of the clinical and anamnestic data of premature newborns at birth, as well as the determination of indicators that take into account the level of antioxidant protection, will make it possible to identify a premature baby at the risk for organic injury of the CNS and to correct the therapeutic strategies in the neonatal period.

Reprint of: Intracellular Production of Superoxide Radical and of Hydrogen Peroxide by Redox Active Compounds

Several compounds have been found capable of diverting the electron flow in Escherichia coli and thus causing increased intracellular production of O2− and H2O2. One indication of this electron-shunting action was increased cyanide-resistant respiration and one cellular response was increased biosynthesis of the manganese-containing superoxide dismutase and of catalase. Blocking cytochrome oxidase with cyanide or azide increased the electron flow available for reduction of paraquat and presumably of the other exogenous compounds tested and thus increased their biological effects. Paraquat, pyocyanine, phenazine methosulfate, streptonigrin, juglone, menadione, plumbagin, methylene blue, and azure C were all effective in elevating intracellular production of O2− and H2O2. The effect of alloxan appeared paradoxical in that it increased cyanide-resistant respiration without significantly increasing the cell content of the manganese-superoxide dismutase and with only a small effect on the level of catalase. The alloxan effect on cyanide-resistant respiration was artifactual and was due to an oxygen-consuming reaction between alloxan and cyanide, rather than to a diversion of the intracellular electron flow. With paraquat as a representative electron-shunting compound, the increase in biosynthesis of the manganese-superoxide dismutase was prevented by inhibitors of transcription or of translation, but not by an inhibitor of replication. The increase in this enzyme activity, caused by paraquat and presumably by the other compounds, was thus due to de novo enzyme synthesis activated or derepressed at the level of transcription.

“Obesity and Insulin Resistance” Is the Component of the Metabolic Syndrome Most Strongly Associated with Oxidative Stress

Metabolic syndrome (MS) is not a homogeneous entity, but this term refers to the coexistence of factors that increase the risk for the development of type 2 diabetes and cardiovascular disease. There are different versions of the criteria for the diagnosis of MS, which makes the population of patients diagnosed with MS heterogeneous. Research to date shows that MS is associated with oxidative stress (OS), but it is unclear which MS component is most strongly associated with OS. The purpose of the study was to investigate the relationship between the parameters of OS and the presence of individual elements of MS in young adults, as well as to identify the components of MS by means of principal components analysis (PCA) and to investigate how the parameters of OS correlate with the presence of individual components. The study included 724 young adults with or without a family history of coronary heart disease (population of the MAGNETIC study). Blood samples were taken from the participants of the study to determine peripheral blood counts, biochemical parameters, and selected parameters of OS. In addition, blood pressure and anthropometric parameters were measured. In subjects with MS, significantly lower activity of superoxide dismutase (SOD), copper- and zinc-containing SOD (CuZnSOD), and manganese-containing SOD (MnSOD) were found, along with significantly higher total antioxidant capacity (TAC) and significantly lower concentration of thiol groups per gram of protein (PSH). We identified three components of MS by means of PCA: “Obesity and insulin resistance”, “Dyslipidemia”, and “Blood pressure”, and showed the component “Obesity and insulin resistance” to have the strongest relationship with OS. In conclusion, we documented significant differences in some parameters of OS between young adults with and without MS. We showed that “Obesity and insulin resistance” is the most important component of MS in terms of relationship with OS.

Combination of oncolytic adenovirus ZD55 harboring TRAIL-IETD-MnSOD and cytokine-induced killer cells against lung cancer.

BackgroundOur study aimed to investigate the effect of cancer-targeting gene-virotherapy and cytokine-induced killer (CIK) cell immunotherapy on lung cancer.MethodsCIK cells were obtained from peripheral blood mononuclear cells using interferon (IFN)-γ, interleukin (IL)-2, and CD3 monoclonal antibody. The CIK cells were infected with oncolytic adenovirus ZD55 harboring tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), manganese-containing superoxide dismutase (MnSOD), and TRAIL-isoleucine-aspartate-threonine-glutamate (IETD)-MnSOD. The cells were then cocultured with lung cancer cell lines A549 and NCI-H1650, normal cell line BEAS-2B, or injected into an A549 xenograft mouse model.ResultsProliferation, colony formation, and invasion of A549 and NCI-H1650 cells were significantly inhibited by co-cultivation with CIK cells carrying oncolytic adenoviruses (in order) ZD55-TRAIL-IETD-MnSOD > ZD55-TRAIL + ZD55-MnSOD > ZD55-MnSOD > ZD55-TRAIL. Compared to BEAS-2B cells, the production of IFN-γ, TNF-α, and lactate dehydrogenase (LDH) in tumor cells was increased. Tumor volume in the xenograft model and Ki-67 expression in tumor samples were reduced after injection of CIK cells carrying oncolytic adenoviruses, in the same order as the in vivo experiments. Levels of IFN-γ, TNF-α, and LDH contents were also increased in the same order.ConclusionsOur studies confirmed the high efficacy of combined oncolytic adenovirus ZD55 harboring TRAIL-IETD-MnSOD and CIK cells against lung cancer.

SigB regulates stress resistance, glucose starvation, MnSOD production, biofilm formation, and root colonization in Bacillus cereus 905.

Bacillus cereus 905, originally isolated from wheat rhizosphere, exhibits strong colonization ability on wheat roots. Our previous studies showed that root colonization is contributed by the ability of the bacterium to efficiently utilize carbon sources and form biofilms and that the sodA2 gene-encoded manganese-containing superoxide dismutase (MnSOD2) plays an indispensable role in the survival of B. cereus 905 in the wheat rhizosphere. In this investigation, we further demonstrated that the ability of B. cereus 905 to resist adverse environmental conditions is partially attributed to activation of the alternative sigma factor σB, encoded by the sigB gene. The sigB mutant experienced a dramatic reduction in survival when cells were exposed to ethanol, acid, heat, and oxidative stress or under glucose starvation. Analysis of the sodA2 gene transcription revealed a partial, σB-dependent induction of the gene during glucose starvation or when treated with paraquat. In addition, the sigB mutant displayed a defect in biofilm formation under stress conditions. Finally, results from the root colonization assay indicated that sigB and sodA2 collectively contribute to B. cereus 905 colonization on wheat roots. Our study suggests a diverse role of SigB in rhizosphere survival and root colonization of B. cereus 905 under stress conditions. KEY POINTS : • SigB confers resistance to environmental stresses in B. cereus 905. • SigB plays a positive role in glucose utilization and biofilm formation in B. cereus. • SigB and SodA2 collectively contribute to colonization on wheat roots by B. cereus.

Identification of genes involved in regulating MnSOD2 production and root colonization in Bacillus cereus 905

sodA2-encoding manganese-containing superoxide dismutase (MnSOD2) in Bacillus cereus 905 plays an essential role in antioxidative stress, nutrition utilization, rhizosphere and phyllosphere colonization. However, the genes involved in regulating the sodA2 expression have not been clearly elucidated in B. cereus. In this study, a genome-wide random insertion mutagenesis was constructed by using transposon TnYLB-1 to identify novel genes regulating the sodA2 expression. Seven mutants that changed the sodA2 expression at both mRNA and protein levels were finally obtained. Sequence analysis and BLAST data showed that the genes disrupted by TnYLB-1 in B. cereus 905 shared high conservations with those in the B. cereus type strain, ATCC 14579. These genes encode heat-inducible transcription repressor, chloride channel protein, recombinase A, ferrous iron transport protein, nucleoside diphosphate kinase, and histidine ammonia-lyase. Besides, we also provided the evidence that the genes regulating the sodA2 expression could influence colonization ability of B. cereus 905 on wheat roots. Specifically, those genes downregulating the sodA2 expression significantly reduced bacterial colonization on wheat roots, and mutants with increased MnSOD2 activities could enhance bacterial population densities on wheat roots to a certain degree. Our work provided information that multiple genes are involved in MnSOD2 production and wheat root colonization. The molecular regulatory pathways through which these genes modulate the sodA2 expression and root colonization need to be investigated extensively in the future.

The recA gene is crucial to mediate colonization of Bacillus cereus 905 on wheat roots.

Bacillus cereus 905, one of the plant growth-promoting rhizobacteria (PGPRs), is capable of colonizing wheat roots in a large population size. From previous studies, we learned that the sodA2-encoding manganese-containing superoxide dismutase (MnSOD2) is important for B. cereus 905 to survive in wheat rhizosphere. In this investigation, we demonstrated that deletion of the recA gene, which codes for the recombinase A, significantly reduced MnSOD2 expression at both the mRNA and the protein levels. Through comparison with the wild-type, the ∆recA showed a dramatic decrease in cell survival after exposure to 50 μM paraquat or 15 mM H2O2. Evidence indicated that the recA gene of B. cereus 905 also notably regulated nutrition utilization efficiency, biofilm formation, and swarming motility. The root colonization examination showed that the ∆recA had a 1000- to 2500-fold reduction in colonization on wheat roots, suggesting that RecA plays an indispensable role in effective colonization on wheat roots by B. cereus 905. Taken together, the recA gene positively regulates MnSOD2 production and nutrition utilization and protects B. cereus 905 cells against paraquat and H2O2. Besides, biofilm formation and swarming motility of B. cereus 905 are promoted by RecA. Finally, RecA significantly contributes to wheat root colonization of B. cereus 905. Our results showed the important role of RecA during physiological processes in B. cereus 905, especially for colonization on wheat roots. Our findings will point out a research direction to study the colonization mechanisms of B. cereus 905 in the future and provide potential effective strategy to enhance the biocontrol efficacy of PGPR strains. KEY POINTS : • RecA plays an indispensable role in root colonization of B. cereus.

A year in the salt marsh: Seasonal changes in gill protein expression in the temperate intertidal mussel Geukensia demissa

Organisms living in temperate and polar regions experience extensive seasonal changes in the physical and biotic environment, including temperature, insolation, and food availability, among other factors. Sessile intertidal organisms respond to such seasonal fluctuations largely through physiological and biochemical means, because their behavioral responses are severely limited. In this study, we used a proteomic approach to examine changes in seasonal protein expression of gill from the intertidal mussel Geukensia demissa, a keystone species of the western Atlantic salt marsh, over the course of one year. Gill tissue of mussels collected in summer had the greatest number of proteins significantly increased in abundance (37 of 592 spots detected on two-dimensional polyacrylamide gels), although autumn mussels revealed a comparable proportion of up-regulated proteins (31 spots). In contrast, the number of proteins changing in abundance in winter and spring mussels were substantially smaller (15 and 9, respectively). Identification of these proteins revealed both expected and unanticipated changes to the proteome. Maintenance of gill cilia dominates in the summer when filter-feeding is most active, as evidenced by cytoskeletal proteins such as tektin-4 and tubulin isoforms; a signal of protection from heat stress is also present in summer (e.g., heat shock cognate 70). In autumn oxidative stress protection (peroxiredoxin-5 and manganese-containing superoxide dismutase) and aerobic ATP synthetic capacity (ATP synthase subunits a and delta) appear to increase. In winter a signal of cold-induced oxidative stress is apparent (Mn-SOD and NADP-dependent isocitrate dehydrogenase), perhaps in association with heavy metal toxicity and exposure to pathogens. Gill tissue from spring shows relatively little environmental acclimatization, other than a possible increase in protein synthesis capacity.

Effects of Dietary Iron Concentration on Manganese Utilization in Broilers Fed with Manganese-Lysine Chelate-Supplemented Diet.

Dietary iron (Fe) influences manganese (Mn) utilization in chickens fed with inorganic Mn-supplemented diet. This study aimed to determine if dietary Fe levels affect Mn utilization in broilers fed with organic Mn-supplemented diet. Nine hundred 8-day-old broilers were randomly assigned to 1 of 6 treatments in a 3 (Fe level) × 2 (Mn source) factorial arrangement after feeding Mn- and Fe-unsupplemented diets for 7days. The broilers were fed the basal diets (approximately 28mg Mn/kg and 60mg Fe/kg) supplemented with 0, 80, or 160mg/kg Fe (L-Fe, M-Fe, or H-Fe), and 100mg/kg Mn from Mn sulfate (MnSO4) or manganese-lysine chelate (MnLys) for 35days. The H-Fe diet decreased (P < 0.05) body weight gain and feed intake as compared with L-Fe and M-Fe diets regardless of dietary Mn sources. Dietary Fe levels did not influence (P > 0.10) serum Mn concentration in MnLys-treated broilers, but serum Mn concentration decreased (P < 0.05) with dietary Fe increasing in MnSO4-treated broilers. The Mn concentration in the duodenum and tibia decreased (P < 0.05) with increasing dietary Fe levels regardless of dietary Mn sources, and MnLys increased (P < 0.04) these indices as compared with MnSO4. Dietary Fe levels did not significantly influence (P > 0.11) Mn concentration and activity and mRNA abundance of manganese-containing superoxide dismutase (MnSOD) in the heart of MnLys-treaded broilers, but the H-Fe diet decreased (P < 0.05) these indices in MnSO4-treated broilers as compared with M-Fe and L-Fe diets. The L-Fe diet increased (P < 0.001) duodenal divalent metal transporter 1 mRNA abundance when compared with the M-Fe and H-Fe diets on day 42, regardless of dietary Mn sources. The M-Fe and H-Fe diets decreased (P < 0.001) duodenal ferroportin 1 (FPN1) mRNA level when compared with the L-Fe diet in MnSO4-treated broilers, while dietary Fe levels did not significantly influence (P > 0.40) duodenal FPN1 mRNA abundance in MnLys-treated broilers. These results indicated dietary Fe levels decreased Mn utilization in MnSO4-treated broilers, but did not influence Mn utilization in MnLys-treated broilers evaluated by Mn concentrations in the serum and heart, and the activity and mRNA expression of heart MnSOD.

Resveratrol improves left ventricular remodeling in chronic kidney disease via Sirt1‐mediated regulation of FoxO1 activity and MnSOD expression

Left ventricular remodeling commonly complicates end-stage renal disease following chronic kidney disease (CKD). This study investigated the therapeutic efficacy of resveratrol (RSV), a polyphenolic compound, on left ventricular remodeling in subtotal nephrectomy rats and sought to uncover the underlying molecular mechanisms. Subtotal nephrectomy caused renal dysfunction, such as gradual increases in serum creatinine and blood urea nitrogen, glomerular sclerosis, and tubulointerstitial fibrosis. In addition, subtotal nephrectomy also resulted in significant increases in myocyte cross-sectional area, interstitial and perivascular fibrosis, and left ventricular dilatation. All these detrimental effects were alleviated in the presence of RSV. Mechanistically, RSV treatment led to the upregulation of manganese-containing superoxide dismutase (MnSOD) in the heart. Coimmunoprecipitation studies showed that silent information regulator 1 (Sirt1) bound forkhead box protein O1 (FoxO1) and thus reduced acetylated FoxO1. RSV strengthened this interaction between Sirt1 and FoxO1. Loss of one allele of Sirt1 aggravated renal damage, myocyte hypertrophy, and interstitial fibrosis in nephrectomized mice. Taken together, our data show that Sirt1 is an important mediator for the protective roles of RSV on renal and heart damage in CKD rodent model, and FoxO1 and MnSOD are likely downstream targets of Sirt1. Therefore, Sirt1 might be a potential therapeutic target for the treatment of left ventricular remodeling caused by CKD.

Effects of Lonicera confusa and Astragali Radix extracts supplementation on egg production performance, egg quality, sensory evaluation, and antioxidative parameters of laying hens during the late laying period

Lonicera confusa (LC) and Astragali Radix (AR) extracts have been shown to have antioxidant and anti-inflammatory activities in human. To determine whether LC or/and AR extracts had similar functions to improve the egg production and egg quality, 1,440 (52-wk-old) Lohmann pink-shell hens were randomly distributed into 4 treatments with nine replicates of 40 hens. The hens were fed a basal diet (CON) or the basal diet supplemented with 0.1% LC extracts, 0.1% AR extracts, or 0.1% LC extracts plus 0.1% AR extracts (LC-AR) for 12 wk. The eggs were collected on week 6 and 12 for analysis, and the plasma and ovaries were collected at end of trial. Dietary treatment did not influence (P < 0.05) egg production, egg weight, and feed conversion ratio. However, LC-AR addition increased (P < 0.02) yolk color and sensory quality of hard-boiled eggs compared to other groups. The LC-AR supplementation increased (P = 0.02), and LC addition tended to increase (P = 0.08) Haugh unit of eggs on week 12 compared to CON. The LC-AR supplementation decreased (P < 0.001), and LC or AR individual addition tended to decrease (P < 0.10) plasma malondialdehyde concentration compared to CON. Conversely, LC supplementation increased (P = 0.02) total superoxide dismutase activity, and LC or/and AR supplementation increased the activities of manganese-containing superoxide dismutase (MnSOD) (P < 0.08) and glutathione peroxidase (GSH-Px) (P < 0.01) in plasma, and the mRNA abundance of MnSOD, GSH-Px1, and catalase in ovaries (P < 0.05) compared to CON. The LC or/and AR supplementation decreased the concentrations of interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α) in plasma (P < 0.05), and the mRNA abundance of IL-6 and TNF-α in ovaries (P < 0.04) compared to CON. These results suggested dietary inclusion of LC or/and AR improved the albumen quality, and a blend of LC and AR improved yolk color, which were associated with the enhancement of antioxidant capacity and the suppression of systemic inflammation in hens.

Effects of dietary inclusion of Radix Bupleuri and Radix Astragali extracts on the performance, intestinal inflammatory cytokines expression, and hepatic antioxidant capacity in broilers exposed to high temperature

The Radix Bupleuri (RB) and Radix Astragali (RA) extracts have anti-inflammatory and antioxidant functions in humans. To determine whether RB and RA extracts had these functions in chronic heat-stressed broilers, 560 15-day-old male broilers were assigned to 7 groups of 8 replicates each (10 birds per replicate), and were under following conditions: 36 °C for 8 h (09:00-17:00) and 30 °C for the remaining time. The broilers were fed the basal diet (control) or the basal diet supplemented with 200 or 400 mg/kg RB extracts (RB200 or RB400), 600 or 800 mg/kg RA extracts (RA600 or RA800), RB200 plus RA800 (RB200-RA800), or RB400 plus RA600 (RB400-RA600) for 28 days. The RB extracts contained 40.1 mg saikosaponins/g, and RA extracts contained 80.0 mg Astragalus polysaccharide/g. Dietary inclusion of RB or/and RA extracts increased (P < 0.05) body weight (BW) of broilers on d 42 and body weight gain during d 15-42. The RB200 and RA800 combination had an additive effect on the BW of broilers when compared to RB200 or RA800 individuals. Thus, the control, RB200, RA800, and RB200-RA800 groups were selected to investigate this additive effect. On d 42, RA800 or RB200-RA800 supplementation decreased (P < 0.05) the mRNA abundance of interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha in the jejunum of broilers as compared to the control, whereas no significance was observed in these indices between RA800 and RB200-RA800 treatments. When compared to control, RB200, RA800, or RB200-RA800 supplementation decreased (P < 0.01) malondialdehyde concentration, RA800 or RB200-RA800 supplementation increased (P < 0.05) manganese-containing superoxide dismutase (MnSOD) activity, and RB200 or RB200-RA800 supplementation increased (P < 0.04) catalase (CAT) activity in the liver on d 42. Dietary inclusion of RB200, RA800, or RB200-RA800 increased the mRNA expression of hepatic MnSOD and CAT on d 42. Hepatic CAT activity and the mRNA abundance of MnSOD and CAT were higher (P < 0.05) in RB200-RA800 treatment when compared to RB200 or RA800 treatment. These results suggested dietary inclusion of RB or/and RA extracts improved the growth performance of broilers exposed to high temperature, possibly due to the reduction of intestinal inflammation and the increase of hepatic antioxidant capacity.

The production of short chain fatty acid and colonic development in weaning piglets.

Weaning process widely affects the small intestinal structure and function in piglets, while the responses of large intestine to weaning stress are still obscure. The purpose of this study was to determine the developmental changes (i.e., short chain fatty acids (SCFAs) concentrations, growth parameters, crypt-related indices and antioxidant capacity) in colon of piglet during weaning. Forty piglets were weaned at day 21 and euthanized to collect colonic tissues and digesta samples on day 0, 1, 3, 7 and 14 post-weaning (n=8). Piglet growth performance was improved (p<.001) on day 7 and 14 post-weaning. The concentrations of acetate, propionate, butyrate, valerate, isobutyrate, isovalerate and total SCFAs were higher (p<.001) during the late post-weaning period. The mRNA abundances of SCFAs transporters were greater (p<.001) on day 7 and 14. The absolute and relative weights, absolute length and perimeter of colon were greater (p<.001) on day 7 and 14. Similarly, post-weaning increases (p<.001) in colonic crypt depth and Ki67 positive cells numbers per crypt were observed during the same period. Colonic crypt fission indices decreased (p<.01), while total crypt numbers increased (p<.001) on day 14 after weaning. Moreover, total SCFAs concentration was significantly associated with colonic growth parameters and Ki67 cells/crypt (p<.001). In addition, catalase content was decreased on day 3, 7, and 14, whereas, the concentrations of total superoxide dismutase (T-SOD) and manganese-containing superoxide dismutase (MnSOD) were higher (p<.05) on day 1 and 3 post-weaning. These results showed that weaning process has a significant effect on colonic growth and development, which might be associated with the change of SCFAs concentrations in colon.

Effects of Dietary Iron on Manganese Utilization in Broilers Fed with Corn-Soybean Meal Diet.

To investigate the effects of dietary iron (Fe) levels on manganese (Mn) utilization, 900 8-day-old broilers were randomly assigned to 1 of 6 treatments in a 3 (Fe level) × 2 (Mn level) factorial arrangement after feeding Mn- and Fe-unsupplemented diet for 7days. The broilers were then fed with basal corn-soybean meal diets (approximately 28mg Mn/kg and 60mg Fe/kg) added with 0, 80, or 160mg/kg Fe (L-Fe, M-Fe, or H-Fe), and 0 or 100mg/kg Mn for 35days. Body weight gain was lower for H-Fe broilers than that for L-Fe and M-Fe broilers. On day 42, H-Fe broilers had lower serum Mn concentration as compared with L-Fe and M-Fe broilers, and tibia Mn concentration decreased as dietary Fe increased. In Mn-supplemented broilers, liver Mn was lower in L-Fe and H-Fe treatments than that in M-Fe treatment. H-Fe treatment decreased Mn concentration and manganese-containing superoxide dismutase (MnSOD) activity in the heart when compared with L-Fe and M-Fe treatments. Dietary Fe did not significantly influence Mn concentrations in the liver and heart, and heart MnSOD activity in Mn-unsupplemented broilers. In the duodenum, L-Fe treatment decreased divalent metal transporter 1 (DMT1) mRNA abundance when compared with M-Fe and H-Fe treatments, and ferroportin 1 (FPN1) mRNA level was higher in M-Fe treatment than that in L-Fe and H-Fe treatments. These results suggested H-Fe diet decreased Mn status in broilers evaluated by Mn concentrations in serum and heart, and heart MnSOD activity. Dietary Fe influenced Mn absorption possibly through effects on duodenal DMT1 and FPN1 expression.

UVB-induced inactivation of manganese-containing superoxide dismutase promotes mitophagy via ROS-mediated mTORC2 pathway activation

Mitochondria are major sites of energy metabolism that influence numerous cellular events, including immunity and cancer development. Previously, we reported that the mitochondrion-specific antioxidant enzyme, manganese-containing superoxide dismutase (MnSOD), has dual roles in early- and late-carcinogenesis stages. However, how defective MnSOD impacts the chain of events that lead to cell transformation in pathologically normal epidermal cells that have been exposed to carcinogens is unknown. Here, we show that UVB radiation causes nitration and inactivation of MnSOD leading to mitochondrial injury and mitophagy. In keratinocytes, exposure to UVB radiation decreased mitochondrial oxidative phosphorylation, increased glycolysis and the expression of autophagy-related genes, and enhanced AKT Ser/Thr kinase (AKT) phosphorylation and cell growth. Interestingly, UVB initiated a prosurvival mitophagy response by mitochondria-mediated reactive oxygen species (ROS) signaling via the mammalian target of the mTOR complex 2 (mTORC2) pathway. Knockdown of rictor but not raptor abrogated UVB-induced mitophagy responses. Furthermore, fractionation and proximity-ligation assays reveal that ROS-mediated mTOC2 activation in mitochondria is necessary for UVB-induced mitophagy. Importantly, pretreatment with the MnSOD mimic MnTnBuOE-2-PyP5+ (MnP) attenuates mTORC2 activation and suppresses UVB-induced mitophagy. UVB radiation exposure also increased cell growth as assessed by soft-agar colony survival and cell growth assays, and pretreatment with MnP or the known autophagy inhibitor 3-methyladenine abrogated UVB-induced cell growth. These results indicate that MnSOD is a major redox regulator that maintains mitochondrial health and show that UVB-mediated MnSOD inactivation promotes mitophagy and thereby prevents accumulation of damaged mitochondria.

Protective effects of whey on rat liver damage induced by chronic alcohol intake.

In 2012, alcohol liver disease resulted in 3.3 million-5.9% of global deaths. This study introduced whey protection capacity against chronic alcohol-induced liver injury. Rats were orally administered to 12% ethanol solution in water (ad libitum, average 8.14 g of ethanol/kg body weight (b.w.)/day) alone or combined with whey ( per os, 2 g/kg b.w./day). After 6-week treatment, chronic ethanol consumption induced significant histopathological liver changes: congestion, central vein dilation, hepatic portal vein branch dilation, Kupffer cells hyperplasia, fatty liver changes, and hepatocytes focal necrosis. Ethanol significantly increased liver catalase activity and glutathione reductase protein expression without significant effects on antioxidative enzymes: glutathione peroxidase (GPx), copper-zinc-containing superoxide dismutase (CuZnSOD) and manganese-containing superoxide dismutase (MnSOD). Co-treatment with whey significantly attenuated pathohistological changes induced by ethanol ingestion and increased GSH-Px and nuclear factor kappa B (NF-κB) protein expression. Our results showed positive effects of whey on liver chronically exposed to ethanol, which seem to be associated with NF-κB-GPx signaling.