Efficacy of ulvan on immune response and immuno-antioxidant gene modulation in Labeo rohita against columnaris disease.

This study reports the effect of ulvan enriched diet on the influence of growth, changes in hemato-biochemical indices, improvement of antioxidant system, enhancement of innate-adaptive immunity and modification of immuno-antioxidant genes expression in Labeo rohita against Flavobacterium columnaris. The weight gain (WG) was significantly high (P > 0.05) in unchallenged normal and challenged fish fed with diets enriched with 25 and 50 mg kg-1 ulvan; the FCR was better (P > 0.05) when fed with 50 mg kg-1 enriched diet. In normal fish fed with or without ulvan supplementation was noted 100% survival rate (SR). In both groups, the red blood cell (RBC) and while blood cell (WBC) counts increased significantly (P > 0.05) when fed with 50 mg kg-1 ulvan diet whereas the hemoglobin (Hb) level increased significantly on being fed with 25 and 50 mg kg-1 ulvan diets. The SOD activity was enhanced significantly in both groups fed with any dose of ulvan diets whereas the MDA and GPx activity increased only with 25 and 50 mg kg-1 ulvan diets. The phagocytic (PC) activity significantly increased with any enriched diet and control diet groups while the respiratory burst (RB) activity increased only with 50 mg kg-1 ulvan diet. The alternate complement pathway (ACP), activity of lysozyme (Lyz), and immunoglobuline M (IgM) were better in both groups fed with 50 mg kg-1 ulvan diet. The SOD and GPx antioxidant gene expression were significantly high in both groups fed with any ulvan diet while the Nrf2 gene expression was high with 50 mg kg-1 ulvan diet. The IL-1ß, TNFα, hepcidin, Lyz, and IgM cytokines or proteins mRNA expression were significant in both groups fed with all ulvan supplement diet whereas the ß-2M expression was significant only with 50 mg kg-1 ulvan diet. The present research indicates that both L. rohita groups fed with 50 mg kg-1 ulvan diet significantly improved growth, antioxidant system, immune defense system, and immuno-antioxidant related gene expression against F. columnaris.

MicroRNA-155 deficiency attenuates inflammation and oxidative stress in experimental autoimmune prostatitis in a TLR4-dependent manner.

To explore the mechanism of microRNA-155 (miR-155) deficiency, protecting against experimental autoimmune prostatitis (EAP) in a toll-like receptor 4 (TLR4)-dependent manner. After wild-type (WT) and miR-155-/- mice were injected with complete Freund's adjuvant and prostate antigen to establish EAP model, half were randomly selected for injection with lipopolysaccharide (LPS, a TLR4 ligand). The following experiments were then performed: von Frey filaments, hematoxylin-eosin (HE) staining, real time quantitative polymerase chain reaction (qRT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA). And the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and the level of Malondialdehyde (MDA) were detected by corresponding kits.miR-155-/- mice with prostatitis exhibited the attenuated pelvic tactile allodynia/hyperalgesia and the suppressed TLR4/nuclear factor-kappa B (NF-κB) pathway as compared with the WT mice with prostatitis. In addition, LPS enhanced the upregulation of miR-155 and the activation of the TLR4/NF-κB pathway in the prostatic tissues of WT mice with EAP. Furthermore, prostatitis mice had aggravated inflammation scores accompanying the increased interleukin (IL)-1ß, tumor necrosis factor-α, IL-6, interferon-γ, IL-12, and MDA in prostatic tissues with the decreased IL-10, SOD and GSH-Px, and the unaltered IL-4. Compared with the mice from the WT + EAP group and the miR-155-/- + EAP + LPS group, mice from the miR-155-/- + EAP group had decreased inflammation and oxidative stress. miR-155 deficiency ameliorated pelvic tactile allodynia/hyperalgesia in EAP mice and improved inflammation and oxidative stress in prostatic tissues in a TLR4-dependent manner involving NF-κB activation, thereby exerting a therapeutic effect in chronic prostatitis treatment.

Effects of dietary myo-inositol on growth, antioxidative capacity, and nonspecific immunity in skin mucus of taimen Hucho taimen fry.

In this study, the effects of dietary myo-inositol on the skin mucosal immunity and growth of taimen (Hucho taimen) fry were determined. Triplicate groups of 500 fish (initial weight 5.58 ± 0.15 g) were fed different diets containing graded levels of myo-inositol (28.75, 127.83, 343.83, 565.81, and 738.15 mg kg-1) until satiation for 56 days. Thereafter, the nonspecific skin mucus immune parameters, antioxidative capacity, and growth performance were measured. The skin mucus protein and the activities of alkaline phosphatase were significantly higher than those in the control group (P < 0.05). However, there were no significant differences in lysozyme activity among the treatments (P > 0.05). The antimicrobial activity and minimum inhibitory concentration of the skin mucus were increased significantly by myo-inositol supplementation (P < 0.05). The superoxide dismutase, catalase, and glutathione peroxidase activities were significantly elevated in the treatment groups (P < 0.05), whereas the malondialdehyde contents were significantly decreased (P < 0.05). Low-level myo-inositol (28.75 mg kg-1) led to a significantly lower weight gain, feed efficiency, condition factor, and survival rate compared with the other treatments (P < 0.05). In conclusion, dietary myo-inositol deficiency (28.75 mg kg-1) adversely affects the skin mucus immune parameters, antioxidative capacity, and growth performance of Hucho taimen fry.

Response of a novel selenium-dependent glutathione peroxidase from thick shell mussel Mytilus coruscus exposed to lipopolysaccharide, copper and benzo[α]pyrene.

Glutathione peroxidase (GPx) plays an important antioxidant role in cellular defense against environmental stress. In the present study, a novel selenium-dependent glutathione peroxidase termed McSeGPx firstly identified in thick shell mussel Mytilus coruscus. McSeGPx consists of 197 amino acid residues, characterized with one selenocysteine residue encoded by an opal stop codon TGA, one selenocysteine insertion sequence (SECIS) in the 3' untranslated region (UTR), two active site motifs and one signature sequence motif. McSeGPx transcripts were constitutively expressed in all examined tissues, and were significantly induced in gills and digestive glands with the stimulations of lipopolysaccharide (LPS), copper (Cu) and benzo[α]pyrene (B[α]P). Additionally, rough increases in McSeGPx activity were detected in both tissues under the challenge of LPS, Cu and B[α]P. Collectively, these results suggested that McSeGPx affiliate to selenocysteine dependent GPx (SeGPx) family and might play an important role in mediating the environmental stressors and antioxidant response in M. coruscus.

Influence of Graded Levels of l-Theanine Dietary Supplementation on Growth Performance, Carcass Traits, Meat Quality, Organs Histomorphometry, Blood Chemistry and Immune Response of Broiler Chickens.

l-theanine is a water-soluble non-proteinous amino acid mainly found in green tea leaves. Despite the availability of abundant literature on green tea, studies on the use of l-theanine as a feed additive in animals, and especially broilers are limited. The objective of this study was, therefore, to evaluate the effect of different dietary levels of l-theanine on meat quality, growth performance, immune response, and blood metabolites in broilers. A total of 400 day-old broiler chicks were randomly divided into four treatment groups using a completely randomized design; C-control, basal diet; 100LT-basal diet + 100 mg l-theanine/kg diet; 200LT-basal diet + 200 mg l-theanine/kg diet; and 300LT-basal diet + 300 mg l-theanine/kg diet. Results revealed that the intermediate level of l-theanine (200 mg/kg diet) showed better results in terms of body weight gain (BWG), feed consumed (FC), and feed conversion ratio (FCR) as compared with the other supplemented groups and the control. The live weight eviscerated weight and gizzard weight were higher in all l-theanine levels as compared to those of the control group. Increased weight (p ≤ 0.05) of spleen and bursa were found in group 200LT (200 mg l-theanine/kg diet). Concerning meat color parameters, values for yellowness (b*), and redness (a*) were greater in l-theanine-supplemented groups than the control. Supplementing broiler diet with l-theanine reduced (p = 0.02) total serum cholesterol contents while increased HDL. Further analysis revealed lower relative serum cytokines (IL-2 and INF-γ) and reduced mRNA expression of TNF-α and IL-6 in thymus, and IFN-γ and IL-2 in spleen in the treated group. Moreover, supplementation with 200 mg/kg of l-theanine improved antioxidant status in blood by increasing SOD, GSH-Px, and relative CAT levels. It is concluded that the optimum supplementation level of l-theanine is 200 mg/kg of diet because it resulted in improved performance parameters in broilers. However, higher levels of l-theanine (300 mg/kg diet) may have deleterious effects on performance and health of broiler chickens.

[Human selenium-containing single-chain variable fragment with glutathione peroxidase activity protects NIH3T3 fibroblast against oxidative damage].

Ultraviolet B (UVB medium wave, 280-315 nm) induces cellular oxidative damage and apoptosis by producing reactive oxygen species (ROS). Glutathione peroxidase functions as an antioxidant by catalyzing the reduction of hydrogen peroxide, the more important member of reactive oxygen species. A human selenium-containing single-chain variable fragment (se-scFv-B3) with glutathione peroxidase activity of 1288 U/µmol was generated and investigated for its antioxidant effects in UVB-induced oxidative damage model. In particular, cell viability, lipid peroxidation extent, cell apoptosis, the change of mitochondrial membrane potential, caspase-3 activity and the levels of intracellular reactive oxygen species were assayed. Human se-scFv-B3 protects NIH3T3 cells against ultraviolet B-induced oxidative damage and subsequent apoptosis by prevention of lipid peroxidation, inhibition of the collapse of mitochondrial membrane potential as well as the suppression of the caspase-3 activity and the level of intracellular ROS. It seems that antioxidant effects of human se-scFv-B3 are mainly associated with its capability to scavenge reactive oxygen species, which is similar to that of the natural glutathione peroxidase.

Selenoproteins and oxidative stress-induced inflammatory tumorigenesis in the gut.

Selenium is an essential micronutrient that is incorporated into at least 25 selenoproteins encoded by the human genome, many of which serve antioxidant functions. Because patients with inflammatory bowel disease (IBD) demonstrate nutritional deficiencies and are at increased risk for colon cancer due to heightened inflammation and oxidative stress, selenoprotein dysfunction may contribute to disease progression. Over the years, numerous studies have analyzed the effects of selenoprotein loss and shown that they are important mediators of intestinal inflammation and carcinogenesis. In particular, recent work has focused on the role of selenoprotein P (SEPP1), a major selenium transport protein which also has endogenous antioxidant function. These experiments determined SEPP1 loss altered immune and epithelial cellular function in a murine model of colitis-associated carcinoma. Here, we discuss the current knowledge of SEPP1 and selenoprotein function in the setting of IBD, colitis, and inflammatory tumorigenesis.

Selenium Alleviates Aflatoxin B1-Induced Immune Toxicity through Improving Glutathione Peroxidase 1 and Selenoprotein S Expression in Primary Porcine Splenocytes.

Selenium (Se) is generally known as an essential micronutrient and antioxidant for humans and animals. Aflatoxin B1 (AFB1) is a frequent contaminant of food and feed, causing immune toxicity and hepatotoxicity. Little has been done about the mechanisms of how Se protects against AFB1-induced immune toxicity. The aim of this present study is to investigate the protective effects of Se against AFB1 and the underlying mechanisms. The primary splenocytes isolated from healthy pigs were stimulated by anti-pig-CD3 monoclonal antibodies and treated by various concentrations of different Se forms and AFB1. The results showed that Se supplementation alleviated the immune toxicity of AFB1 in a dose-dependent manner, as demonstrated by increasing T-cell proliferation and interleukin-2 production. Addition of buthionine sulfoximine abrogated the protective effects of SeMet against AFB1. SeMet enhanced mRNA and protein expression of glutathione peroxidase 1 (GPx1), selenoprotein S (SelS), and thioredoxin reductase 1 without and with AFB1 treatments. Furthermore, knockdown of GPx1 and SelS by GPx1-specific siRNA and SelS-specific siRNA diminished the protective effects of SeMet against AFB1-induced immune toxicity. It is concluded that SeMet diminishes AFB1-induced immune toxicity through increasing antioxidant ability and improving GPx1 and SelS expression in splenocytes. This study suggests that organic selenium may become a promising supplementation to protect humans and animals against the decline in immunity caused by AFB1.

Two variants of selenium-dependent glutathione peroxidase from the disk abalone Haliotis discus discus: Molecular characterization and immune responses to bacterial and viral stresses.

Glutathione peroxidase (GPx) is an essential member of the antioxidant systems of living organisms and may be involved in immune defense against pathogenic invasion. In the current study, two selenium-dependent glutathione peroxidases (AbSeGPxs) that shared 54.3% identity were identified from the disk abalone Haliotis discus discus. The open reading frames (ORFs) of AbSeGPx-a and AbSeGPx-b coded for 222 and 220 amino acids, respectively, with a characteristic selenocysteine residue encoded by an opal stop codon (TGA). The conserved selenocysteine insertion sequence (SECIS) element was predicted in the 3' untranslated region (UTR) of both isoforms, and they were found to form two stem-loop structures. Amino acid comparison and phylogenetic studies revealed that the AbSeGPxs were closely related to those in other mollusk species and were evolutionarily distinct from those of other taxonomic groups. The SYBR Green qPCR was employed in investigating the transcripts of AbSeGPxs. The expression of AbSeGPxs mRNA was examined in different embryonic developmental stages and differential expression patterns for AbSeGPx-a and AbSeGPx-b were noted. Meanwhile, the highest expression of AbSeGPxs was detected in the hepatopancreas of healthy adult animals. Next, transcriptional levels were profiled in hemocytes of adults to determine the immune responses of AbSeGPxs to microbial infections. The results revealed the significant up-regulation of AbSeGPx-a in a time-dependent manner after bacterial (Listeria monocytogenes and Vibrio parahaemolyticus) and viral (viral hemorrhagic septicemia virus) infections. Consequently, these findings indicate that AbSeGPx-a and AbSeGPx-b might be involved in the embryonic development of disk abalone and the regulation of immune defense system of adult animals.

T cell lipid peroxidation induces ferroptosis and prevents immunity to infection.

The selenoenzyme glutathione peroxidase 4 (Gpx4) is a major scavenger of phospholipid hydroperoxides. Although Gpx4 represents a key component of the reactive oxygen species-scavenging network, its relevance in the immune system is yet to be defined. Here, we investigated the importance of Gpx4 for physiological T cell responses by using T cell-specific Gpx4-deficient mice. Our results revealed that, despite normal thymic T cell development, CD8(+) T cells from T(ΔGpx4/ΔGpx4) mice had an intrinsic defect in maintaining homeostatic balance in the periphery. Moreover, both antigen-specific CD8(+) and CD4(+) T cells lacking Gpx4 failed to expand and to protect from acute lymphocytic choriomeningitis virus and Leishmania major parasite infections, which were rescued with diet supplementation of high dosage of vitamin E. Notably, depletion of the Gpx4 gene in the memory phase of viral infection did not affect T cell recall responses upon secondary infection. Ex vivo, Gpx4-deficient T cells rapidly accumulated membrane lipid peroxides and concomitantly underwent cell death driven by ferroptosis but not necroptosis. These studies unveil an essential role of Gpx4 for T cell immunity.

Analgesic and Anti-Inflammatory Activities of Rosa taiwanensis Nakai in Mice.

In this study, we evaluated the analgesic and anti-inflammatory activities of a 70% ethanol extract from Rosa taiwanensis Nakai (RTEtOH). The analgesic effect was determined using acetic acid-induced writhing response and formalin test. The anti-inflammatory activity was evaluated by λ-carrageenan-induced paw edema in mice. The anti-inflammatory mechanism of RTEtOH was examined by measuring the levels of cyclooxygenase-2 (COX-2), nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-6, and malondialdehyde (MDA) in the paw edema tissue and the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GRd) in the liver tissue. The betulinic acid and oleanolic acid contents of RTEtOH were assayed by HPLC. The results showed that RTEtOH decreased the acetic acid-induced writhing responses (1.0 g/kg) and the late phase of the formalin-induced licking time (0.5 and 1.0 g/kg). In the anti-inflammatory models, RTEtOH (0.5 and 1.0 g/kg) reduced the paw edema at 3, 4, and 5 h after λ-carrageenan administration. Moreover, the anti-inflammatory mechanisms might be due to the decreased levels of COX-2, TNF-α, IL-1ß, and IL-6, as well as the inhibition of NO and MDA levels through increasing the activities of SOD, GPx, and GRd. The contents of two active compounds, betulinic acid and oleanolic acid, were quantitatively determined. This study demonstrated the analgesic and anti-inflammatory activities of RTEtOH and provided evidence to support its therapeutic use in inflammatory diseases.

Polyphenolics isolated from virgin coconut oil inhibits adjuvant induced arthritis in rats through antioxidant and anti-inflammatory action.

We evaluated the protective efficacy of the polyphenolic fraction from virgin coconut oil (PV) against adjuvant induced arthritic rats. Arthritis was induced by intradermal injection of complete Freund's adjuvant. The activities of inflammatory, antioxidant enzymes and lipid peroxidation were estimated. PV showed high percentage of edema inhibition at a dose of 80mg/kg on 21st day of adjuvant arthritis and is non toxic. The expression of inflammatory genes such as COX-2, iNOS, TNF-α and IL-6 and the concentration of thiobarbituric acid reactive substance were decreased by treatment with PV. Antioxidant enzymes were increased and on treatment with PV. The increased level of total WBC count and C-reactive protein in the arthritic animals was reduced in PV treated rats. Synovial cytology showed that inflammatory cells and reactive mesothelial cells were suppressed by PV. Histopathology of paw tissue showed less edema formation and cellular infiltration on supplementation with PV. Thus the results demonstrated the potential beneficiary effect of PV on adjuvant induced arthritis in rats and the mechanism behind this action is due to its antioxidant and anti-inflammatory effects.

Lactobacillus casei and Lactobacillus acidophilus regulate inflammatory pathway and improve antioxidant status in collagen-induced arthritic rats.

In view of well-established immunomodulatory properties of Lactobacillus, present investigation was carried out to evaluate antioxidant and anti-inflammatory potential of Lactobacillus casei and Lactobacillus acidophilus, against inflammatory pathway and oxidative stress developed in an experimental model of arthritis. Collagen-induced arthritis (CIA) model was used. Oral administration of L. casei, L. acidophilus, standard antiarthritic drug indomethacin, and vehicle were started after induced arthritis and continued up to day 28. Interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-1ß, IL-17, IL-4, and IL-10 levels were estimated in serum. In parallel, oxidative stress parameters were also measured from synovial effsuate. All rats were graded for arthritis score at the end of each week. L. casei, L. acidophilus, and indomethacin treatment significantly downregulated proinflammatory and upregulated anti-inflammatory cytokines at P<0.0001. They have significantly decreased oxidative stress in synovial effsuate (P<0.0001) and also arthritis score (P<0.05). Protection provided by L. casei and L. acidophilus was more pronounced than that of indomethacin. These lines of evidence suggest that L. casei and L. acidophilus exert potent protective effect against CIA. It further establishes effective anti-inflammatory and antioxidant properties of Lactobacillus. However, additional clinical investigations are needed to prove the efficacy of Lactobacillus in treatment/management of rheumatoid arthritis.

Differences in associations between markers of antioxidative defense and asthma are sex specific.

BACKGROUND: Lungs are exposed to high levels of oxygen, air pollutants, and smoke, all of which stimulate the production of reactive oxygen species (ROS). In addition, inflammatory cells produce ROS, and thus there may be increased demand for antioxidants, including antioxidant enzymes, in inflammatory lung diseases such as asthma. Sex-specific differences have been noted for asthma, which in postpubertal subjects is predominantly found in females. These sex-specific differences may be associated with differences on the molecular level as well. OBJECTIVE: The aim of this cross-sectional study was to examine associations between markers of antioxidative defense and asthma, and to investigate whether these associations were different between women and men. METHODS: Based on the European Community Respiratory Health Survey protocol, subjects were enrolled in a study of asthma risk factors. The multicenter study was conducted in 5 west Danish counties between 2003 and 2006, and the subjects were recruited as a case-enriched random sample of 10,000 Danish inhabitants aged 20 to 44 years selected by their civil registration number. Participants were identified by positive answers to asthma questions on a screening questionnaire, random sampling, or both. Serum selenium concentrations and antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase [GPX], glutathione reductase [GR], and glucose-6-phosphate dehydrogenase [G6PD]) in erythrocytes were measured. Asthma was defined as either current asthma symptoms with bronchial hyperresponsiveness (BHR) or a continuous asthma score based on 8 questions. RESULTS: A total of 1191 mostly white women and men (mean [SD] age, 34.0 [7.1] and 35.1 [7.1] years, respectively) were enrolled in the study. Current asthma symptoms were present in 29.9% (200/670) of women and 22.5% (117/521) of men, with women reporting more positive answers (51.1% vs 40.9%, respectively; P < 0.01) to asthma questions. Serum selenium concentrations were measured in 1151 subjects (640 women, 511 men), and antioxidant enzyme activities were measured in 295 subjects (161 women, 134 men). Women had higher enzyme activities of most antioxidant enzymes (GPX, P = 0.006; GR, P < 0.001; and G6PD, P = 0.009) than did men. Although the serum selenium concentration was inversely associated with asthma in both sexes, there was a female preponderance, with 3.5% lower serum selenium in subjects with current asthma symptoms with BHR (n = 77) compared with controls (n = 287). GR activity was associated with asthma in men, with 5.7% higher enzyme activity in subjects with current asthma symptoms with BHR (n = 14) compared with controls (n = 77). However, a significant interaction with gender was observed for analyses of GR (P = 0.02), but not for analyses of selenium. CONCLUSIONS: In this study of asthma risk factors, women had higher levels of enzyme activities than did men in a randomly selected Danish population, and sex-specific differences were found in the associations between markers of antioxidative defense and asthma.

Identification and cloning of a selenium-dependent glutathione peroxidase from tiger shrimp, Penaeus monodon, and its transcription following pathogen infection and related to the molt stages.

Complementary (c)DNA encoding glutathione peroxidase (GPx) messenger (m)RNA of the tiger shrimp Penaeus monodon was obtained from haemocytes by a reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) method. The 1321-bp cDNA contained an open reading frame (ORF) of 564bp, a 69-bp 5'-untranslated region (UTR), and a 688-bp 3'-UTR containing a poly A tail and a conserved selenocysteine insertion sequence (SECIS) element. The molecular mass of the deduced amino acid (aa) sequence (188 aa) was 21.05kDa long with an estimated pI of 7.68. It contains a putative selenocysteine residue which is encoded by the unusual stop codon, (190)TGA(192), and forms the active site with residues Glu(75) and Trp(143). Comparison of amino acid sequences showed that tiger shrimp GPx is more closely related to vertebrate GPx1, in accordance with those in Litopenaeus vannamei and Macrobrachium rosenbergii. GPx cDNA was synthesised in lymphoid organ, gills, heart, haemocytes, the hepatopancreas, muscles, and intestines. After injected with either Photobacterium damsela or white spot syndrome virus (WSSV), the respiratory bursts of shrimp significantly increased in order to kill the pathogen, and induced increases in the activities of superoxide dismutase and GPx, and regulation in the expression of cloned GPx mRNA to protect cells against damage from oxidation. The GPx expression significantly increased at stage D(0/1), and then gradually decreased until stage C suggesting that the cloned GPx might play a role in the molt regulation of shrimp.

Filarial selenium glutathione peroxidase: a probable immunodiagnostic marker for lymphatic filariasis.

Lymphatic filariasis (LF) caused by Wuchereria bancrofti is widely prevalent in tropical and subtropical countries. Night blood film examination is most commonly used for diagnosis of filariasis but is cumbersome and labour intensive. In order to develop an indirect ELISA-based immunodiagnostic test, the importance of antifilarial IgG subclasses was evaluated in bancroftian filariasis patients. Blood samples from healthy individuals and different categories of LF patients were used to estimate the diagnostic potential of selenium glutathione peroxidase antigen purified from the bovine filarial parasite Setaria cervi. This antigen reacted with both IgG(1) and IgG(4); however, the IgG1 response was greater in microfilaraemic patients and the IgG(4) response was higher in chronic filarial patients. The diagnostic sensitivity of IgG(1) and IgG(4) was 97% and 96% whereas specificity was determined to be 95% and 98% respectively. Our observations suggest that SeGSHPx could be an alternative diagnostic marker for the detection of bancroftian filariasis in an endemic area.

Protection against Schistosoma mansoni utilizing DNA vaccination with genes encoding Cu/Zn cytosolic superoxide dismutase, signal peptide-containing superoxide dismutase and glutathione peroxidase enzymes.

Protection against Schistosoma mansoni infection in C57BL/6 female mice was evaluated by two DNA vaccination strategies. Mice were either vaccinated by intramuscular injection with pcDNAI/Amp constructs encoding either Cu/Zn cytosolic superoxide dismutase (CT-SOD), signal peptide-containing SOD (SP-SOD), glutathione peroxidase (GPX(bb)) or a mutated form of GPX (GPX(m)), or primed with naked DNA constructs and boosted with recombinant vaccinia virus (RVV) containing the same genes. Animals were then challenged with S. mansoni and the level of protection was assessed as the reduction in worm burden. CT-SOD showed significant levels of protection compared to the control group, ranging between 44 and 60%, while SP-SOD exhibited from 22 to 45%. GPX(bb) showed levels of protection (23-55%) higher than GPX(m) (25-34%). The prime-boost strategy gave the same results as naked DNA or recombinant vaccinia virus alone except in the case of GPX, where the protection was 85%.

Selenium-dependent glutathione peroxidase-GI is a major glutathione peroxidase activity in the mucosal epithelium of rodent intestine.

Gpx2 mRNA, encoding a selenium-dependent glutathione peroxidase (GPX-GI), has been found to be highly expressed in the gastrointestinal tract (GI) mucosal epithelium. In this study, we show that GPX-GI is produced in the mucosal epithelium of the adult rat GI tract and that the activity levels are comparable to that from GPX-1. Post-mitochondrial supernatant GPX activity from the mucosal epithelium of the complete length of the small intestine was partially purified. A sample enriched for putative GPX-GI was fractionated by SDS-polyacrylamide gel electrophoresis. Polypeptides of 21 kDa and 22 kDa were digested with trypsin. After resolving the tryptic peptides by high pressure liquid chromatography (HPLC), the major peaks were analyzed for their amino acid sequence by Microflow-HPLC-Tandem Mass Spectrometry and automated Edman degradation sequencing. Both methods revealed that the 21-kDa sample contained rat GPX-GI determined by the sequence homology with the deduced mouse GPX-GI polypeptide sequence. Rat GPX-1 was also detected in the samples. AntiGPX-GI and antiGPX-1 antibodies were used to determine the distribution of the respective isoenzyme activities along the length of the intestine and with respect to the crypt to villus axis in rats. GPX-GI and GPX-1 activities were uniformly distributed in the middle and lower GI tract and with respect to the crypt to villus axis. GPX-GI activity accounted nearly the same percentage of the total GPX activity as GPX-1 in all of the these compartments. Studies on the distal ileum segment of wildtype and Gpx1 gene knockout mice showed that GPX-GI activity was also at parity with GPX-1 in the mucosal epithelium of this segment.

The majority of human glutathione peroxidase type 5 (GPX5) transcripts are incorrectly spliced: implications for the role of GPX5 in the male reproductive tract.

An epididymis-specific, secretory glutathione peroxidase (GPX5) has been proposed previously to play a role in protecting mammalian sperm membranes from the deleterious effects of lipid peroxidation, which, if not contained, can lead to reduced fertilizing capacity. Here we report the cDNA cloning of human GPX5 and show that the majority of transcripts contain a 118 nt frame-shifting deletion, arising, most likely, from inappropriate excision of exon 3 during processing. Antisera raised against recombinant human GPX5 cross-reacted with rat and macaque (Macaca fascicularis) epididymal proteins of the size expected for full-length, active GPX5. However, no similar reactivity could be demonstrated in any of the human samples tested.

Radioimmunoassay of glutathione peroxidase in human serum.

Glutathione peroxidase (GSHPx) was purified from human serum and used for immunization of rabbits. Antiserum bound up to 75% of added 125I-GSHPx after precipitation with a second antibody. Human serum, but not sera from eight animal species, inhibited the binding of labelled GSHPx, indicating that the antiserum did not react with GSHPx from these species. GSHPx could be measured in less than 10 microliters of human serum by radioimmunoassay. In sera with widely varying selenium concentrations (0.1-2.9 mumol/l) the amount of GSHPx protein (0.3-6.3 mg/l) was strongly correlated with GSHPx activity (r = 0.94) and it was also correlated with serum selenium concentrations (r = 0.64). This indicates that GSHPx protein may be a valuable biological marker of selenium status. In samples with serum selenium concentrations of 0.8-1.2 mumol/l, the concentration of GSHPx was 3.3 (0.4) mg/l (mean (S.D.)), or 0.04 (0.005) mumol/l. This corresponded to 0.16 (0.02) mumol/l of GSHPx selenium and 16% (2.8)% of total serum selenium. The data suggest that the method can be used to measure the proportion of serum selenium that is located in GSHPx. Following storage of serum at room temperature, both serum GSHPx protein and activity declined, but addition of glutathione protected both GSHPx protein and activity.