72 results on '"Stagsted, J."'
Search Results
2. Colostrum and bioactive, colostral peptides differentially modulate the innate immune response of intestinal epithelial cells
- Author
-
Jørgensen, A L, Juul-Madsen, H R, and Stagsted, J
- Published
- 2010
3. Absence of both glutathione perioxidase activity and glutathione in bovine milk
- Author
-
Stagsted, J.
- Subjects
fluids and secretions ,Food security, food quality and human health ,food and beverages - Abstract
Glutathione peroxidases are selenium-dependent, antioxidant enzymes that catalyse the removal of hydroperoxides using the tripeptide glutathione as reducing substrate. The presence and importance of glutathione peroxidase for the oxidative stability of bovine milk is unclear. We failed to detect any specific activity in bovine milk using careful and comprehensive assay conditions. The apparent activity in milk that has been ascribed previously to glutathione peroxidase was shown to be independent of added hydroperoxide, completely inhibited by >6 mM EDTA, and could not be immunoprecipitated with a specific antiserum against the extracellular form of glutathione peroxidase. These results are incompatible with activity of glutathione peroxidase in bovine milk as shown by parallel assays of glutathione peroxidase activity in bovine plasma and in contrast to reports using human milk. Further, there is very little indigenous glutathione in bovine milk to be used as a reducing substrate for glutathione peroxidase. In fact, glutathione added to milk is metabolised rapidly, probably by the action of sulphydryl oxidase.
- Published
- 2006
4. A search for bioactive peptides in fish mucus
- Author
-
Djurhuus, D.D., primary, Sydnes, M., additional, Provan, F., additional, Stagsted, J., additional, Joensen, H., additional, and Mikalsen, S.-O., additional
- Published
- 2012
- Full Text
- View/download PDF
5. Inhibition of internalization of glucose transporters and IGF-II receptors. Mechanism of action of MHC class I-derived peptides which augment the insulin response in rat adipose cells
- Author
-
Stagsted J, Olsson L, Geoffrey Holman, Sw, Cushman, and Satoh S
- Subjects
Epididymis ,Male ,Glucose Transporter Type 1 ,Glucose Transporter Type 4 ,Monosaccharide Transport Proteins ,Histocompatibility Antigens Class I ,Methylglucosides ,Muscle Proteins ,Biological Transport ,Peptide Fragments ,Receptor, IGF Type 2 ,Rats ,Kinetics ,Adipose Tissue ,Insulin-Like Growth Factor II ,3-O-Methylglucose ,Animals ,Insulin ,Electrophoresis, Polyacrylamide Gel ,Cells, Cultured - Abstract
Peptides from the alpha 1 domain of the major histocompatibility complex class I antigen (MHC class I), e.g. Dk-(61-85) and Dk-(62-85), have been shown previously to augment glucose uptake in insulin-stimulated cells and to inhibit insulin receptor internalization (Stagsted, J., Reaven, G. M., Hansen, T., Goldstein, A., and Olsson, L. (1990) Cell 62, 297-307). We now report that these peptides inhibit by 80-100% the internalization of glucose transporters (GLUT4) and insulin-like growth factor II (IGF-II) receptors in insulin-stimulated cells and correspondingly double insulin-stimulated glucose transport activity and the number of GLUT4 and IGF-II receptors on the cell surface. In addition, the peptides enhance the apparent affinity about 3-fold of IGF-II binding to its receptor. It is concluded that the effects of the peptides on glucose transport and IGF-II binding are a consequence of the peptide-mediated inhibition of internalization of GLUT4 and IGF-II receptor. The active peptides are derived from the alpha 1 domain of a MHC class I molecule, suggesting that the latter is involved in regulation of internalization of cell surface integral membrane proteins such as the GLUT4 and IGF-II and insulin receptors.
- Published
- 1993
6. Ascorbic acid, alpha-tocopherol, and oregano supplements reduce stress-induced deterioration of chicken meat quality
- Author
-
Young, JF, primary, Stagsted, J, additional, Jensen, SK, additional, Karlsson, AH, additional, and Henckel, P, additional
- Published
- 2003
- Full Text
- View/download PDF
7. Sensory colour assessment of fresh meat from pigs supplemented with iron and vitamin E
- Author
-
O’Sullivan, M.G, primary, Byrne, D.V, additional, Stagsted, J, additional, Andersen, H.J, additional, and Martens, M, additional
- Published
- 2002
- Full Text
- View/download PDF
8. Regulation of receptor internalization by the major histocompatibility complex class I molecule.
- Author
-
Olsson, L, primary, Goldstein, A, additional, and Stagsted, J, additional
- Published
- 1994
- Full Text
- View/download PDF
9. Amino acid residues essential for biological activity of a peptide derived from a major histocompatibility complex class I antigen.
- Author
-
Stagsted, J, primary, Mapelli, C, additional, Meyers, C, additional, Matthews, B W, additional, Anfinsen, C B, additional, Goldstein, A, additional, and Olsson, L, additional
- Published
- 1993
- Full Text
- View/download PDF
10. Insulinomimetic effect on glucose transport by epidermal growth factor when combined with a major histocompatibility complex class I-derived peptide.
- Author
-
Stagsted, J., primary, Ziebe, S., additional, Satoh, S., additional, Holman, G.D., additional, Cushman, S.W., additional, and Olsson, L., additional
- Published
- 1993
- Full Text
- View/download PDF
11. A preformed, ordered structure of a 25-residue peptide derived from a major histocompatibility complex class I antigen is required to affect insulin receptor function
- Author
-
Stagsted, J., primary, Baase, W.A., additional, Goldstein, A., additional, and Olsson, L., additional
- Published
- 1991
- Full Text
- View/download PDF
12. A short-term intervention trial with selenate, selenium-enriched yeast and selenium-enriched milk: effects on oxidative defence regulation.
- Author
-
Ravn-Haren G, Bügel S, Krath BN, Hoac T, Stagsted J, Jørgensen K, Bresson JR, Larsen EH, and Dragsted LO
- Published
- 2008
- Full Text
- View/download PDF
13. Effect of changes in fruit and vegetable intake on plasma antioxidant defenses in humans.
- Author
-
Serafini, Mauro, Rio, Daniele Del, Crozier, Alan, Benzie, Iris F. F., Dragsted, L. O., Ravn-Haren, G., Hansen, M., Kall, M., Breinholt, V., Jakobsen, J., Rasmussen, S. E., Pedersen, A., Sandström, B., Hermetter, A., Basu, S., Castenmiller, J., Stagsted, J., Skibsted, L. H., and Loft, S.
- Published
- 2005
- Full Text
- View/download PDF
14. Effect of changes in fruit and vegetable intake on plasma antioxidant defenses in humans.
- Author
-
Serafini, Mauro, Del Rio, Daniele, Crozier, Alan, Benzie, Iris F. F., Dragsted, L. O., Ravn-Haren, G., Hansen, M., Kall, M., Breinholt, V., Jakobsen, J., Rasmussen, S. E., Pedersen, A., Sandström, B., Hermetter, A., Basu, S., Castenmiller, J., Stagsted, J., Skibsted, L. H., and Loft, S.
- Published
- 2004
15. Sensory colour assessment of fresh meat from pigs supplemented with iron and vitamin E
- Author
-
O`Sullivan, M. G., Byrne, D. V., Stagsted, J., Andersen, H. J., and Martens, M.
- Published
- 2002
- Full Text
- View/download PDF
16. Inhibition of insulin receptor phosphorylation by peptides derived from major histocompatibility complex class I antigens.
- Author
-
Hansen, T, Stagsted, J, Pedersen, L, Roth, R A, Goldstein, A, and Olsson, L
- Abstract
Peptides from the alpha 1 region (residues 61-85) of the D and K molecules of the major histocompatibility complex class I antigens inhibit insulin-induced tyrosine kinase activity of the purified human insulin receptors (IRs) as measured both by autophosphorylation and IR-mediated substrate [poly(Glu,Tyr)] phosphorylation. Half-maximal effect of the Dk-(61-85) peptide on IR autophosphorylation is obtained at 1.2 microM, and almost complete inhibition of IR kinase activity is obtained at 10 microM peptide. The corresponding K kappa-(61-85) peptide has a significantly weaker effect on autophosphorylation. No such effects are observed with nine peptides of similar length, but unrelated to major histocompatibility complex class I antigens. Neither of the major histocompatibility complex class I-derived peptides has any effect on the constitutively active kinase of a genetically engineered cytoplasmic IR domain. Further, insulin binding to IR is unaltered in the presence of the major histocompatibility complex class I-derived peptides. The inhibitory activity of the peptides on insulin-induced IR phosphorylation facilitated the observation that IRs require insulin to become substrate for an independent tyrosine kinase. In the presence of an inhibitory peptide, the constitutively active cytoplasmic IR kinase domain only phosphorylates the intact IR in the presence of insulin. We conclude that the tyrosine kinase activity of IRs may be altered by peptide interaction at an allosteric site and, moreover, IRs require insulin to assume a conformation permitting phosphorylation by an independent kinase.
- Published
- 1989
- Full Text
- View/download PDF
17. Correlation between insulin receptor occupancy and tyrosine kinase activity at low insulin concentrations and effect of major histocompatibility complex class I-derived peptide.
- Author
-
Stagsted, J, Hansen, T, Roth, R A, Goldstein, A, and Olsson, L
- Abstract
In rat adipocytes, insulin dose-response curves were determined for the following effects in the same cells under the same conditions: glucose uptake, binding to insulin receptors (IR), IR autophosphorylation in vivo and in vitro, IR tyrosine kinase activity and insulin-stimulated phosphatidylinositol (PI) kinase. All the EC50 values were essentially the same (mean +/- S.E.M. was 7 +/- 1 nM), except for glucose uptake, which was 170 pM. Using an improved method, we were able to measure PI kinase activity at picomolar concentrations of insulin (> 30 pM) corresponding to the EC50 for glucose uptake. These experiments showed that insulin-stimulated increase in glucose uptake was associated with an increase in antiphosphotyrosine antibody precipitable PI kinase activity, consistent with the view that IR tyrosine kinase activity may be involved in insulin-mediated signaling of glucose uptake. Small peptides (17-25 residues long) derived from major histocompatibility complex class I have previously been shown to inhibit IR internalization without any effect on the affinity of insulin to the receptor. It is now shown that the peptide-mediated inhibition of internalization, which doubles the number of insulin-occupied receptors at an insulin concentration of 70 pM, also results in a corresponding enhancement of PI kinase activity and glucose uptake. Thus, the receptors arrested on the cell surface by the peptide are biologically active.
- Published
- 1993
18. Insulinomimetic effect on glucose transport by epidermal growth factor when combined with a major histocompatibility complex class I-derived peptide
- Author
-
Stagsted J, Ziebe S, Satoh S, Geoffrey Holman, Sw, Cushman, and Olsson L
- Subjects
Male ,Glucose Transporter Type 1 ,Glucose Transporter Type 4 ,Epidermal Growth Factor ,Monosaccharide Transport Proteins ,Histocompatibility Antigens Class I ,Molecular Sequence Data ,H-2 Antigens ,Methylglucosides ,Muscle Proteins ,Biological Transport ,Rats ,Glucose ,Adipose Tissue ,3-O-Methylglucose ,Animals ,Insulin ,Amino Acid Sequence ,Histocompatibility Antigen H-2D - Abstract
Peptides derived from the alpha 1-region of the murine H-2Dk molecule enhance glucose uptake in rat adipose cells above the maximum obtained with insulin stimulation alone (Stagsted, J., Reaven, G. M., Hansen, T., Goldstein, A., and Olsson, L. (1990) Cell 62, 297-307). We now describe that epidermal growth factor (EGF) in combination with the same peptides, Dk-(61-85) and Dk-(62-85), stimulates cellular glucose uptake 5-7 times over the basal level, i.e. to 30-50% of the maximal insulin effect. EGF alone increased glucose uptake by only approximately 50% above basal and the peptide alone by 100% above basal. Maximal effect of EGF and peptide was reached in 10-20 min with 30 microM peptide (EC50 10-15 microM) and 50 nM EGF (EC50 1-2 nM). The effect of EGF and peptide on glucose uptake was additive to that of insulin and peptide until the maximal level attained with insulin and peptide was reached. The combined effect of EGF plus peptide on glucose transport was associated with a recruitment of GLUT4 molecules to the plasma membrane. However, the phosphatidylinositol (PI) kinase which is activated by insulin was not activated by EGF plus peptide. Thus, the effect of EGF plus peptide on glucose uptake seems independent of the activity status of the insulin receptor. 125I-Labeled EGF bound specifically to rat adipose cells with an apparent affinity of approximately 2 nM and Bmax approximately 5 x 10(3). However, the major histocompatibility complex (MHC) peptides did not affect EGF-stimulated internalization of EGF receptor, in contrast to their effect on the insulin receptors. Transforming growth factor alpha had an effect similar to EGF on glucose uptake. Three other peptides derived from other parts of murine MHC class I had no effect on glucose uptake in combination with EGF. Thus, EGF in combination with certain MHC class I-derived peptides is insulinomimetic concerning glucose transport and this effect is independent of the insulin receptor activity.
19. The 6-a-day study
- Author
-
Lars Ove Dragsted, Pedersen, A., Hermetter, A., Basu, S., Hansen, M., Lejla Gitte Ravn-Haren, Kall, M., Breinholt, V., Castenmiller, J. J. M., Stagsted, J., Jakobsen, J., Skibsted, Leif H., Rasmussen, S. E., Steffen Loft, and Sandström, B.
20. A short-term intervention trial with selenate, selenium-enriched yeast and selenium-enriched milk: effects on oxidative defence regulation
- Author
-
Gitte Ravn-Haren, Bügel, S., Olsson, P., Åkesson, B., Flemming Jessen, Jensen, S. B., Britta Krath, Hoac, T., Stagsted, J., Erik Huusfeldt Larsen, and Dragsted, L. O.
21. Extraction and characterization of candidate bioactive compounds in different tissues from salmon (Salmo salar)
- Author
-
Falkenberg, S. S., Svein-Ole Mikalsen, Joensen, H., Stagsted, J., and Nielsen, H. H.
- Subjects
Marine by-products ,Salmon tissue ,Radical scavenging ,SDG 14 - Life Below Water ,Natural compounds - Abstract
There is an interest in bioprospecting organisms from the aquatic environment to find novel bioactive compounds with health promoting or other functional properties. The aim of this study was to evaluate extracts from untreated and heat-treated salmon tissues for their radical scavenging activities and for their ability to inhibit activity of the proteases angiotensin I-converting enzyme (ACE) and dipeptidyl peptidase 4 (DPP-4). In vitro assays were used to detect these activities and the corresponding candidate bioactive compounds were characterized by LC-MS/MS. Radical scavenging activity was detected in 50 values of 39, 82 and 100 μg/mL, respectively. No ACE or DPP-4 inhibiting activity could be detected. LC-MS/MS analysis of dominating compounds in active fractions from size exclusion chromatography showed that families of related compounds were found in several fractions from different tissues but most pronounced in gills. One family was defined according to content of a specific amino acid sequence (PW). Three families were defined by the m/z value of the smallest compound reported in each family (219, 434 and 403). The three latter families did not contain standard unmodified amino acids, indicating peptides with modified amino acids or other kinds of molecules. Industrial relevance. Bioprospecting in fish tissue traditionally regarded as waste can lead to detection of novel natural bioactive compounds including peptides, which could have nutritional, pharmaceutical or other functional value and be used in health and functional foods, thus increasing the value adding of secondary marine products. A number of naturally occurring antimicrobial peptides have been characterized from fish skin and gills, such as piscidins, but these and other fish tissues may contain numerous other compounds with bioactive properties. Such compounds could be extracted by the subsection of the fish industry that processes marine secondary products and further developed to commercial products. Thus, the identification of novel bioactive compounds could be utilized by the pharmaceutical and biotech industry to develop new products.
22. Novel aspects of health promoting compounds in meat.
- Author
-
Young, J.F., Therkildsen, M., Ekstrand, B., Che, B.N., Larsen, M.K., Oksbjerg, N., and Stagsted, J.
- Subjects
- *
HEALTH promotion , *NUTRITIONAL value of meat , *MEAT quality , *AMINO acid content of food , *BIOACTIVE compounds , *MUSCLE diseases , *PREVENTION - Abstract
Abstract: Meat is an integral part of the human diet. Besides essential amino acids and nutritive factors of high quality and availability, meat provides often overlooked components of importance for human health. These are amino acids and bioactive compounds that may be very important in i) preventing muscle wasting diseases, such as in sarcopenia, ii) reducing food and caloric intake to prevent metabolic syndrome, iii) blood pressure homeostasis via ACE-inhibitory components from connective tissue, and iv) maintaining functional gut environment through meat-derived nucleotides and nucleosides. In addition, meat could be an important source of phytanic acid, conjugated linoleic acids and antioxidants. Further, it becomes increasingly apparent that design of in vitro meat will be possible, and that this development may lead to improved health benefits from commercially viable and sustainable meat products. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
23. Obesity Development in a Miniature Yucatan Pig Model: A Multi-compartmental Metabolomics Study on Cloned and Normal Pigs Fed Restricted or Ad Libitum High-Energy Diets.
- Author
-
Curtasu MV, Knudsen KEB, Callesen H, Purup S, Stagsted J, and Hedemann MS
- Subjects
- Animals, Cloning, Organism adverse effects, Diet, Disease Models, Animal, Energy Intake, Female, Swine, Swine, Miniature, Diet, Western adverse effects, Metabolomics methods, Obesity metabolism
- Abstract
Miniature-pig models for human metabolic disorders such as obesity and metabolic syndrome are gaining popularity. However, in-depth knowledge on the phenotypic and metabolic effects of metabolic dysregulation is lacking, and ad libitum feeding is not well-characterized in these pig breeds. Therefore, an investigation was performed into the metabolome of Yucatan minipigs fed ad libitum or restricted diets. Furthermore, we used cloned and conventional minipigs to assess if cloning reflects a presumably lowered variation between subjects. For 5 months, 17 female Yucatan minipigs were fed either ad libitum or restricted Western-style diets. Serum, urine, and liver tissues were collected and analyzed by non-targeted liquid chromatography-mass spectrometry metabolomics and by biochemical analyses. Several metabolic pathways were deregulated as a result of obesity and increased energy-dense feed intake, particularly the hepatic glutathione pathway and the pantothenic acid and tryptophan metabolic pathways in serum and urine. Although cloned minipigs were phenotypically similar to wild-type minipigs, the metabolomics analysis of serum and liver tissues showed several altered pathways, such as amino acid and purine metabolism. These changes, as an effect of cloning, could limit the use of cloned models in dietary intervention studies and provides no evidence of decreased variability between subjects.
- Published
- 2019
- Full Text
- View/download PDF
24. Caseins from bovine colostrum and milk strongly bind piscidin-1, an antimicrobial peptide from fish.
- Author
-
Kütt ML and Stagsted J
- Subjects
- Animals, Anti-Infective Agents chemistry, Anti-Infective Agents pharmacology, Antimicrobial Cationic Peptides metabolism, Antimicrobial Cationic Peptides pharmacology, Caseins metabolism, Caseins pharmacology, Cattle, Fish Proteins metabolism, Fish Proteins pharmacology, Fishes, Microbial Sensitivity Tests, Molecular Weight, Protein Binding, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Antimicrobial Cationic Peptides chemistry, Caseins chemistry, Colostrum chemistry, Fish Proteins chemistry, Milk chemistry
- Abstract
A model system of bovine colostrum and piscidin, a fish-derived antimicrobial peptide, was developed to study potential interactions of antimicrobial peptides in colostrum. We did not detect any antimicrobial activity of colostrum using the radial plate diffusion assay; in fact colostrum completely abrogated activity of added piscidin. This could not be explained by degradation of piscidin by colostrum, which was less than ten percent. We found that colostrum even protected piscidin against degradation by added proteases. We further observed that colostrum and milk rapidly quenched the fluorescence of fluorescein-piscidin but not that of fluorescein. This effect was not seen with BSA and the specific quenching of fluorescein-piscidin by colostrum was saturably inhibited with unlabeled piscidin. Size exclusion chromatography indicated that fluorescein-piscidin bound to casein micelles with no apparent binding to IgG or whey proteins. Further, addition of pure caseins was able to quench fluorescence of fluorescein-piscidin and to inhibit the antimicrobial activity of piscidin. The interaction between caseins and piscidin could be dissociated by guanidine hydrochloride and recovered piscidin had antimicrobial activity against bacteria. Based on our results we propose that caseins could be carriers for antimicrobial peptides in colostrum and milk., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
25. The effect of high-fat diet on the composition of the gut microbiota in cloned and non-cloned pigs of lean and obese phenotype.
- Author
-
Pedersen R, Andersen AD, Hermann-Bank ML, Stagsted J, and Boye M
- Subjects
- Animals, Bacteria classification, Bacteria genetics, Cloning, Organism, Diet, High-Fat, Female, Male, Swine growth & development, Swine metabolism, Bacteria isolation & purification, Dietary Fats metabolism, Gastrointestinal Tract microbiology, Microbiota, Swine microbiology
- Abstract
The aim of this study was to investigate the effect of high-far-high-energy diet on cloned and non-cloned domestic pigs of both lean and obese phenotype and to evaluate if the lean cloned pigs had a lower inter-individual variation as compared with non-cloned pigs. The microbiota of colon and terminal ileum was investigated in cloned and non-cloned pigs that received a high-far-high-energy diet with either restricted or ad libitum access to feed, resulting in lean and obese phenotypes, respectively. The fecal microbiota of lean pigs was investigated by terminal restriction fragment length polymorphism (T-RFLP). The intestinal microbiota of lean and obese cloned and non-cloned pigs was analyzed by quantitative real time PCR and a novel high-throughput qPCR platform (Fluidigm). Principal component analysis (PCA) of the T-RFLP profiles revealed that lean cloned and non-cloned pigs had a different overall composition of their gut microbiota. The colon of lean cloned pigs contained relatively more bacteria belonging to the phylum Firmicutes and less from the phylum Bacteroidetes than obese cloned pigs as estimated by qPCR. Fluidigm qPCR results revealed differences in specific bacterial groups in the gut microbiota of both lean and obese pigs. Our results suggest that high-far-high-energy diet is associated with changes in the gut microbiota even in the absence of obesity. Overall, the cloned pigs had a different gut microbiota from that of non-cloned pigs. To our knowledge this is the first study to investigate the gut microbiota of cloned domestic pigs of lean and obese phenotype.
- Published
- 2013
- Full Text
- View/download PDF
26. Cloning changes the response to obesity of innate immune factors in blood, liver, and adipose tissues in domestic pigs.
- Author
-
Rødgaard T, Skovgaard K, Stagsted J, and Heegaard PM
- Subjects
- Animals, Blood Proteins genetics, Blood Proteins metabolism, Disease Models, Animal, Down-Regulation physiology, Female, Immunologic Factors genetics, Obesity genetics, Obesity physiopathology, Sus scrofa metabolism, Thinness genetics, Thinness metabolism, Thinness physiopathology, Transcriptome physiology, Up-Regulation physiology, Adipose Tissue metabolism, Cloning, Organism, Immunity, Innate physiology, Immunologic Factors metabolism, Liver metabolism, Obesity metabolism, Sus scrofa genetics
- Abstract
The objective of this study was to evaluate the usefulness of cloned pigs as porcine obesity models reflecting obesity-associated changes in innate immune factor gene expression profiles. Liver and adipose tissue expression of 43 innate immune genes as well as serum concentrations of six immune factors were analyzed in lean and diet-induced obese cloned domestic pigs and compared to normal domestic pigs (obese and lean). The number of genes affected by obesity was lower in cloned animals than in control animals. All genes affected by obesity in adipose tissues of clones were downregulated; both upregulation and downregulation were observed in the controls. Cloning resulted in a less differentiated adipose tissue expression pattern. Finally, the serum concentrations of two acute-phase proteins (APPs), haptoglobin (HP) and orosomucoid (ORM), were increased in obese clones as compared to obese controls as well as lean clones and controls. Generally, the variation in phenotype between individual pigs was not reduced in cloned siblings as compared to normal siblings. Therefore, we conclude that cloning limits both the number of genes responding to obesity as well as the degree of tissue-differentiated gene expression, concomitantly with an increase in APP serum concentrations only seen in cloned, obese pigs. This may suggest that the APP response seen in obese, cloned pigs is a consequence of the characteristic skewed gene response to obesity in cloned pigs, as described in this work. This should be taken into consideration when using cloned animals as models for innate responses to obesity.
- Published
- 2013
- Full Text
- View/download PDF
27. Orosomucoid expression profiles in liver, adipose tissues and serum of lean and obese domestic pigs, Göttingen minipigs and Ossabaw minipigs.
- Author
-
Rødgaard T, Stagsted J, Christoffersen BØ, Cirera S, Moesgaard SG, Sturek M, Alloosh M, and Heegaard PM
- Subjects
- Animals, Disease Models, Animal, Female, Humans, Intra-Abdominal Fat metabolism, Liver immunology, Obesity blood, Orosomucoid metabolism, RNA, Messenger genetics, RNA, Messenger metabolism, Species Specificity, Subcutaneous Fat immunology, Sus scrofa blood, Swine, Swine, Miniature blood, Thinness blood, Thinness genetics, Thinness immunology, Tissue Distribution, Transcriptome, Obesity genetics, Obesity immunology, Orosomucoid genetics, Orosomucoid immunology, Sus scrofa genetics, Sus scrofa immunology, Swine, Miniature genetics, Swine, Miniature immunology
- Abstract
The acute phase protein orosomucoid (ORM) has anti-inflammatory and immunomodulatory effects, and may play an important role in the maintenance of metabolic homeostasis in obesity-induced low-grade inflammation. Even though the pig is a widely used model for obesity related metabolic symptoms, the expression of ORM has not yet been characterized in such pig models. The objective of this study was to investigate the expression of ORM1 mRNA in liver, visceral adipose tissue, subcutaneous adipose tissue (SAT) from the abdomen or retroperitoneal abdominal adipose tissue (RPAT) and SAT from the neck, as well as the serum concentration of ORM protein in three porcine obesity models; the domestic pig, Göttingen minipigs and Ossabaw minipigs. No changes in ORM1 mRNA expression were observed in obese pigs compared to lean pigs in the four types of tissues. However, obese Ossabaw minipigs, but none of the other breeds, showed significantly elevated ORM serum concentrations compared to their lean counterparts. Studies in humans have shown that the expression of ORM was unchanged in adipose tissue depots in obese humans with an increased serum concentration of ORM. Thus in this respect, obese Ossabaw minipigs behave more similarly to obese humans than the other two pig breeds investigated., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
28. Changes in the gut microbiota of cloned and non-cloned control pigs during development of obesity: gut microbiota during development of obesity in cloned pigs.
- Author
-
Pedersen R, Andersen AD, Mølbak L, Stagsted J, and Boye M
- Subjects
- Animals, Bacteroidetes classification, Cloning, Organism, DNA, Bacterial genetics, Female, Gram-Positive Bacteria classification, Mice, Polymorphism, Restriction Fragment Length, Real-Time Polymerase Chain Reaction, Swine, Bacteroidetes isolation & purification, Biota, Diet, High-Fat, Feces microbiology, Gram-Positive Bacteria isolation & purification, Obesity microbiology, Swine Diseases microbiology
- Abstract
Background: Obesity induced by a high-caloric diet has previously been associated with changes in the gut microbiota in mice and in humans. In this study, pigs were cloned to minimize genetic and biological variation among the animals with the aim of developing a controlled metabolomic model suitable for a diet-intervention study. Cloning of pigs may be an attractive way to reduce genetic influences when investigating the effect of diet and obesity on different physiological sites. The aim of this study was to assess and compare the changes in the composition of the gut microbiota of cloned vs. non-cloned pigs during development of obesity by a high-fat/high-caloric diet. Furthermore, we investigated the association between diet-induced obesity and the relative abundance of the phyla Firmicutes and Bacteroidetes in the fecal-microbiota. The fecal microbiota from obese cloned (n = 5) and non-cloned control pigs (n= 6) was investigated biweekly over a period of 136 days, by terminal restriction fragment length polymorphism (T-RFLP) and quantitative real time PCR (qPCR)., Results: A positive correlation was observed between body-weight at endpoint and percent body-fat in cloned (r=0.9, P<0.0001) and in non-cloned control pigs (r=0.9, P<0.0001). Shannon Weaver and principal component analysis (PCA) of the terminal restriction fragments (T-RFs) revealed no differences in the bacterial composition or variability of the fecal microbiota between the cloned pigs or between cloned and non-cloned control pigs. Body-weight correlated positively with the relative abundance of Firmicutes in both cloned (r=0.37; P<0.02) and non cloned-control pigs (r=0.45; P<0.006), and negatively with the abundance of Bacteroidetes in cloned pigs (r=-0.33, P<0.04), but not in the non-cloned control pigs., Conclusion: The cloned pigs did not have reduced inter-individual variation as compared to non-cloned pigs in regard to their gut microbiota in neither the obese nor the lean state. Diet-induced obesity was associated with an increase in the relative abundance of Firmicutes over time. Our results suggest that cloned pigs are not a more suitable animal model for gut microbiota-obesity related studies than non-cloned pigs. This study is the first to evaluate if cloned pigs provide a better animal model than conventional pigs in diet-intervention, obesity and gut microbiota research.
- Published
- 2013
- Full Text
- View/download PDF
29. Expression of innate immune response genes in liver and three types of adipose tissue in cloned pigs.
- Author
-
Rødgaard T, Skovgaard K, Stagsted J, and Heegaard PM
- Subjects
- Animals, Base Sequence, Blood Proteins metabolism, DNA Primers, Enzyme-Linked Immunosorbent Assay, Real-Time Polymerase Chain Reaction, Swine, Adipose Tissue, Cloning, Organism, Gene Expression, Immunity, Innate genetics
- Abstract
The pig has been proposed as a relevant model for human obesity-induced inflammation, and cloning may improve the applicability of this model. We tested the assumptions that cloning would reduce interindividual variation in gene expression of innate immune factors and that their expression would remain unaffected by the cloning process. We investigated the expression of 40 innate immune factors by high-throughput quantitative real-time PCR in samples from liver, abdominal subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and neck SAT in cloned pigs compared to normal outbred pigs. The variation in gene expression was found to be similar for the two groups, and the expression of a small number of genes was significantly affected by cloning. In the VAT and abdominal SAT, six out of seven significantly differentially expressed genes were downregulated in the clones. In contrast, most differently expressed genes in both liver and neck SAT were upregulated (seven out of eight). Remarkably, acute phase proteins (APPs) dominated the upregulated genes in the liver, whereas APP expression was either unchanged or downregulated in abdominal SAT and VAT. The general conclusion from this work is that cloning leads to subtle changes in specific subsets of innate immune genes. Such changes, even if minor, may have phenotypic effects over time, e.g., in models of long-term inflammation related to obesity.
- Published
- 2012
- Full Text
- View/download PDF
30. Liquid chromatography-mass spectrometry based metabolomics study of cloned versus normal pigs fed either restricted or ad libitum high-energy diets.
- Author
-
Christensen KL, Hedemann MS, Jørgensen H, Stagsted J, and Knudsen KE
- Subjects
- Animals, Chromatography, High Pressure Liquid, Chromatography, Reverse-Phase, Cloning, Organism, Creatine blood, Female, Lactic Acid blood, Lipids blood, Metabolomics, Multivariate Analysis, Principal Component Analysis, Spectrometry, Mass, Electrospray Ionization, Sus scrofa genetics, Tandem Mass Spectrometry, Caloric Restriction, Metabolome, Sus scrofa metabolism
- Abstract
Genetically identical cloned pigs should in principle eliminate biological variation and provide more pronounced effects when subjected to, e.g., dietary interventions, but little is known about how phenotype and phenotypic variation is affected by cloning. Therefore, an investigation of the metabolome of cloned pigs compared to normal control pigs was performed to elucidate the variation and possible differences in the metabolic phenotypes during a dietary intervention. A total of 19 control pigs and 17 cloned pigs were given the same high-energy dense diet either ad libitum or in a restricted manner (60% of ad libitum) for ∼6 months, and plasma was subjected to liquid chromatography-mass spectrometry nontargeted metabolomics and biochemical analyses. Low systemic levels of IGF-1 could indicate altered growth conditions and energy metabolism in cloned pigs. In response to ad libitum feeding, clones had a decreased energy intake and lower weight gain compared to controls, and plasma lipid profiles were changed accordingly. Elevated lactate and decreased creatine levels implied an increased anaerobic metabolism in ad libitum fed clones. Less interindividual variation between cloned pigs was however not established, suggesting a strong role for epigenetics and/or the gut microbiota to develop variation.
- Published
- 2012
- Full Text
- View/download PDF
31. Metabolomic phenotyping of a cloned pig model.
- Author
-
Clausen MR, Christensen KL, Hedemann MS, Liu Y, Purup S, Schmidt M, Callesen H, Stagsted J, and Bertram HC
- Subjects
- Animals, Bile chemistry, Female, Lactic Acid blood, Phenotype, Plasma chemistry, Urine chemistry, Cloning, Organism, Metabolomics, Swine genetics, Swine metabolism
- Abstract
Background: Pigs are widely used as models for human physiological changes in intervention studies, because of the close resemblance between human and porcine physiology and the high degree of experimental control when using an animal model. Cloned animals have, in principle, identical genotypes and possibly also phenotypes and this offer an extra level of experimental control which could possibly make them a desirable tool for intervention studies. Therefore, in the present study, we address how phenotype and phenotypic variation is affected by cloning, through comparison of cloned pigs and normal outbred pigs., Results: The metabolic phenotype of cloned pigs (n = 5) was for the first time elucidated by nuclear magnetic resonance (NMR)-based metabolomic analysis of multiple bio-fluids including plasma, bile and urine. The metabolic phenotype of the cloned pigs was compared with normal outbred pigs (n = 6) by multivariate data analysis, which revealed differences in the metabolic phenotypes. Plasma lactate was higher for cloned vs control pigs, while multiple metabolites were altered in the bile. However a lower inter-individual variability for cloned pigs compared with control pigs could not be established., Conclusions: From the present study we conclude that cloned and normal outbred pigs are phenotypically different. However, it cannot be concluded that the use of cloned animals will reduce the inter-individual variation in intervention studies, though this is based on a limited number of animals.
- Published
- 2011
- Full Text
- View/download PDF
32. Mass spectrometric-based protein chips for detection of food-derived bioactive components.
- Author
-
Stagsted J, Jørgensen AL, and Juul-Madsen HR
- Subjects
- Animals, Cattle, Colostrum chemistry, Colostrum metabolism, Humans, Immunity, Innate physiology, Food Analysis methods, Mass Spectrometry methods, Protein Array Analysis methods
- Abstract
Bioactive components in the diet influence our health and well-being beyond that of simple supply of energy and raw materials for biochemical reactions. However, the complex chemistry and composition of our food does not make the identification of potential bioactive components a straightforward task. Bioassays for a multitude of functionalities have to be performed for thousands of different food-derived molecules in order to identify important interactions. Our approach is to directly identify those food molecules that interact with cellular targets based on mass spectrometric (MS) techniques through immobilization of cellular target molecules on glass chips and incubation with various foods. Food-derived molecules that bind with high affinity can then be directly analyzed by MS. We have chosen bovine colostrum, a potent bioactive food, and cellular receptors of the innate immune response as our model for proof of concept.
- Published
- 2010
- Full Text
- View/download PDF
33. Characterization of peroxides formed by riboflavin and light exposure of milk. Detection of urate hydroperoxide as a novel oxidation product.
- Author
-
Clausen MR, Huvaere K, Skibsted LH, and Stagsted J
- Subjects
- Animals, Cattle, Chromatography, Gel, Female, Light, Oxidation-Reduction radiation effects, Hydrogen Peroxide chemistry, Milk chemistry, Milk radiation effects, Peroxides chemistry, Riboflavin chemistry, Uric Acid chemistry
- Abstract
Characterization of peroxides by size exclusion chromatography (SEC) of milk following exposure to riboflavin and light showed that hydrogen peroxide was the most abundant peroxide formed since it could be removed by catalase. Formation of peroxides after separation by SEC showed that hydrogen peroxide formation was primarily increased in the presence of caseins and ascorbate, although whey proteins also were found to contribute. Caseins and beta-lactoglobulin also formed catalase-resistant peroxides, presumably protein hydroperoxides. A catalase-resistant and unstable peroxide was observed in fractions containing urate. Experiments performed with pure urate suggested that urate radicals reacted further with superoxide leading to a urate hydroperoxide. Electron paramagnetic resonance spectroscopy using spin-traps showed that the presence of oxygen was required for urate radical formation, which could be assigned as nitrogen-centered radicals. These results suggest a new route during light-induced oxidation sensitized by flavins, in effect making urate pro-oxidative.
- Published
- 2010
- Full Text
- View/download PDF
34. Colostrum and bioactive, colostral peptides differentially modulate the innate immune response of intestinal epithelial cells.
- Author
-
Jørgensen AL, Juul-Madsen HR, and Stagsted J
- Subjects
- Animals, Bacterial Toxins pharmacology, Cell Line, Chromatography, High Pressure Liquid, Mice, Peptides isolation & purification, Colostrum chemistry, Immunity, Innate, Intestinal Mucosa immunology, Peptides physiology
- Abstract
Characterization and identification of peptides with bioactivity from food have received considerable interest recently since such bioactive components must be adequately documented if they are part of functional food claims. We have characterized peptides from colostrum or those generated by a simulated gastrointestinal digest (GI) and tested them for bioactivity using murine intestinal (mIC(c12)) cells and compared with bioactivity of intact colostrum. The peptides were recovered in the permeate after dialysis. The presence of peptides in the permeate was confirmed by C(18) RP-HPLC, determination of free amino termini and MALDI MS. The bioactivity of the intact colostrum and colostral peptides in the permeate was tested using mIC(c12) cells stimulated in the absence or presence of different bacterial ligands that mediate cellular activation through stimulation of Toll-like receptors (TLR). Whereas intact colostrum generally reduced TLR-mediated signaling, the isolated peptides seemed to either stimulate or reduce the immune response depending on the bacterial ligand used for stimulation. Interestingly, the most potent bioactive peptides originated from nondigested colostrum, which had only been subject to endogenous protease activity. Identified peptides in the nondigested colostrum originated exclusively from the casein fraction of colostrum as shown by MALDI MS/MS identification. Thus, multiple components with different bioactivities towards the innate immune response appear in bovine colostrum.
- Published
- 2010
- Full Text
- View/download PDF
35. Characterization of major radical scavenger species in bovine milk through size exclusion chromatography and functional assays.
- Author
-
Clausen MR, Skibsted LH, and Stagsted J
- Subjects
- Amino Acids chemistry, Animals, Antioxidants analysis, Antioxidants chemistry, Benzothiazoles, Caseins chemistry, Cattle, Chromans, Lactalbumin chemistry, Lactoglobulins chemistry, Milk Proteins chemistry, Peroxides chemistry, Protein Folding, Sulfonic Acids, Whey Proteins, Chromatography, Gel, Free Radical Scavengers analysis, Free Radical Scavengers chemistry, Milk chemistry
- Abstract
Radical scavenging activities of bovine milk components were quantified following size exclusion chromatography (SEC) with postcolumn characterization of fractions using the scavenging of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals (ABTS*(+)) in the Trolox equivalent antioxidant capacity (TEAC) assay and peroxyl radicals formed from cleavage of 2,2'-azobis(2-amidinopropane) (AAPH) in the oxygen radical absorbance capacity (ORAC) fluorometric assay. Caseins were quantitatively the major radical scavenger species in both assays, whereas beta-lactoglobulin (beta-lg) and alpha-lactalbumin (alpha-la) were much less active and only in the peroxyl radical assay. The radical scavenging activity of the caseins could be quantitatively accounted for by their constituent amino acids, as there were no effects of denaturing agents or complete digestion with proteases. In contrast, the activities of the whey proteins were dependent on denaturation or partial hydrolysis and dominated by the free thiol in beta-lg. A component in milk serum with a molecular mass of approximately 100 kDa contributed significantly to both ABTS*(+) and peroxyl radical scavenging but was absent in whey. This radical scavenger was identified as beta-casein. The only significant low molecular weight radical scavenger species were identified as ascorbate and urate in both assays.
- Published
- 2009
- Full Text
- View/download PDF
36. A novel, simple and sensitive ligand affinity capture method for detecting molecular interactions by MALDI mass spectrometry.
- Author
-
Jørgensen AL, Juul-Madsen HR, and Stagsted J
- Subjects
- Affinity Labels chemistry, Angiotensins chemistry, Avidin chemistry, Biotin chemistry, Coumaric Acids chemistry, Lipopolysaccharides chemistry, Models, Molecular, Polymyxin B chemistry, Sensitivity and Specificity, Silanes chemistry, Biotinylation, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods
- Abstract
A simple and sensitive ligand affinity capture method (LAC) was developed to detect biotinylated biomolecules bound to a biotin-avidin base by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI ToF MS). Glass slides covered with a metal film for MALDI MS applications were treated with amino-silane and derivatized with biotin followed by binding of avidin. Washing buffers with high ionic strength increased the specificity of the subsequent binding of biotinylated biomolecules to the avidin layer. A combined thin layer-dried droplet method using alpha-cyano-4-hydroxycinnamic acid (CHCA) in acetone or ethyl acetate resulted in the most intense ions of biotinylated polymyxin B, whereas the matrix conditions did not influence the detection of angiotensin II. Addition of biotinylated biomolecules in the low femtomole to low picomole range resulted in sufficient ion intensity for detection by the LAC method. The LAC concept was extended by binding of biotinylated lipopolysaccharide to the biotin-avidin base followed by preferential capture and specific detection of the binding antagonist polymyxin B., (Copyright (c) 2009 John Wiley & Sons, Ltd.)
- Published
- 2009
- Full Text
- View/download PDF
37. Inhibition of lactoperoxidase-catalyzed 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and tyrosine oxidation by tyrosine-containing random amino acid copolymers.
- Author
-
Clausen MR, Skibsted LH, and Stagsted J
- Subjects
- Enzyme Inhibitors pharmacology, Kinetics, Lactoperoxidase chemistry, Oxidation-Reduction, Polymers chemistry, Polymers pharmacology, Static Electricity, Tyrosine chemistry, Benzothiazoles metabolism, Lactoperoxidase antagonists & inhibitors, Lactoperoxidase metabolism, Peptides pharmacology, Sulfonic Acids metabolism, Tyrosine metabolism, Tyrosine pharmacology
- Abstract
Oxidation of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) by lactoperoxidase was found to be inhibited by tyrosine-containing random amino acid copolymers but not by tyrosine. Both electrostatic effects and polymer size were found to be important by comparison of negatively and positively charged copolymers of varying lengths, with poly(Glu, Tyr)4:1 ([E 4Y 1] approximately 40) as the strongest competitive inhibitor (EC 50 approximately 20 nM). This polymer did not form dityrosine in the presence of lactoperoxidase (LPO) and peroxide. Furthermore, incubation with tert-butyl hydroperoxide, as opposed to hydrogen peroxide, resulted in a peculiar long lag phase of the reaction between the redox intermediate compound II and [E 4Y 1] approximately 40, indicating a very tight association between enzyme and inhibitor. We propose that interactions between multiple positively charged areas on the surface of LPO and the polymer are required for optimal inhibition.
- Published
- 2008
- Full Text
- View/download PDF
38. Short-term effects of selenium supplementation of cows' feed on the content and distribution of selenium, copper and zinc in bovine milk, whey and blood plasma.
- Author
-
Hoac T, Stagsted J, Lundh T, Nielsen JH, and Akesson B
- Subjects
- Animal Feed, Animals, Female, Time Factors, Cattle physiology, Copper analysis, Copper blood, Dietary Supplements, Milk chemistry, Selenium analysis, Selenium blood, Selenium pharmacology, Zinc analysis, Zinc blood
- Abstract
The effect of selenium supplementation of feed on the Se content in bovine milk, whey and plasma, and on the distribution of Se, Zn and Cu in whey and plasma was investigated. In a cross-over study two groups of cows were given a basal feed with 0.16 ppm selenite (approx. 3 mg Se/d) with or without 25 mg yeast Se/d for 2 weeks. In the supplemented group the Se content increased 10-fold in milk, 10-fold in whey and 2-fold in plasma, and after the cessation of the supplementation, selenium in milk decreased with a calculated half-life of 3.5 d. In another experiment, two groups of cows were given either 100 mg yeast Se/d for 1 week or only the basal feed. The increase in Se content in both whole and defatted milk was 40-50-fold, and in whey it was approx. 20-fold. Size-exclusion chromatography of whey using inductively coupled plasma mass spectrometry for detection showed that supplementation increased the proportion of Se in the beta-lactoglobulin-alpha-lactalbumin fraction. Distribution of Cu and Zn was essentially unaffected. In plasma, supplementation increased the Se content in all major Se fractions like selenoprotein P, albumin and low-molecular-weight compounds, but the distribution profiles of Zn and Cu underwent no major changes. The study showed for the first time the rapid kinetics of the Se increase and decrease in milk after the initiation and cessation of supplementation, respectively, and the preferential appearance of Se in the beta-lactoglobulin-alpha-lactalbumin fraction of whey. Milk highly enriched in selenium will be a useful tool for different research purposes.
- Published
- 2008
- Full Text
- View/download PDF
39. n-6 and n-3 fatty acids ratio and vitamin E in porcine maternal diet influence the antioxidant status and immune cell eicosanoid response in the progeny.
- Author
-
Lauridsen C, Stagsted J, and Jensen SK
- Subjects
- Animal Feed, Animals, Fatty Acids chemistry, Fatty Acids metabolism, Female, Milk, Plant Oils metabolism, Pregnancy, Pregnancy, Animal, Sunflower Oil, Swine, Antioxidants metabolism, Dietary Fats metabolism, Eicosanoids metabolism, Fatty Acids, Omega-3 metabolism, Fatty Acids, Omega-6 metabolism, Vitamin E metabolism
- Abstract
Five groups of lactating sows were fed diets containing 8% of either added rapeseed oil, fish oil or sunflower oil and 60 mg vitamin E/kg feed, or the diets with sunflower oil and fish oil, respectively, supplemented with 500 mg vitamin E/kg. Supplementation of vitamin E to the sows increased the concentration of alpha-tocopherol of the muscle, and addition of sunflower oil decreased the activity of glutathione peroxidase in liver cytosol compared to fish oil and rapeseed oil. The composition of fatty acids of alveolar macrophages (AM) of piglets was influenced by the dietary fat sources provided the sows, i.e., the ratio of n-6:n-3 fatty acids was highest in AM of piglets suckling sows of the sunflower oil treatments, and lowest in AM of piglets suckling sows fed fish oil with the rapeseed oil treatment in between. The ex vivo synthesis of prostaglandin E(2) and thromboxane B(2) in AM of piglets suckling sows fed sunflower oil was elevated compared to piglets suckling sows fed fish oil. Vitamin E supplementation to sows enhanced the synthesis of these eicosanoids, and also the concentration of alpha-tocopherol in the AM of the piglets.
- Published
- 2007
- Full Text
- View/download PDF
40. Significance of vitamin E supplementation, dietary content of polyunsaturated fatty acids, and preslaughter stress on oxidative status in pig as reflected in cell integrity and antioxidative enzyme activities in porcine muscle.
- Author
-
Young JF, Rosenvold K, Stagsted J, Nielsen JH, and Andersen HJ
- Subjects
- Abattoirs, Animals, Catalase metabolism, Dietary Supplements, Female, Glutathione Peroxidase metabolism, L-Lactate Dehydrogenase blood, Oxidative Stress, Superoxide Dismutase metabolism, alpha-Tocopherol administration & dosage, Diet, Fatty Acids, Unsaturated administration & dosage, Muscle, Skeletal enzymology, Stress, Physiological, Swine, Vitamin E administration & dosage
- Abstract
The present study investigates the combined effects of feed-induced increase in polyunsaturated fatty acids (PUFA) content and/or alpha-tocopherol content in pig muscles and preslaughter stress on cell integrity. Cell integrity was determined by plasma lactate dehydrogenase (LDH) activity, and antioxidative status of muscle was measured by activities of the antioxidative enzymes catalase, superoxide dismutase, and glutathione peroxidase. Preslaughter stress increased LDH activity, reflecting loss in cell membrane integrity independent of increased content of PUFA and/or alpha-tocopherol. However, feed-induced increase of PUFA decreased the LDH activity in plasma immediately after slaughter. Catalase activity in the muscle tissue increased as a consequence of the high-PUFA diet, which may indicate an increased demand caused by introduction of oxidative labile PUFA.
- Published
- 2005
- Full Text
- View/download PDF
41. Elucidation of membrane destabilization in post-mortem muscles using an extracellular paramagnetic agent (Gd-DTPA): an NMR study.
- Author
-
Bertram HC, Stagsted J, Young JF, and Andersen HJ
- Subjects
- Animals, Cell Membrane drug effects, Electric Stimulation, Hydrogen-Ion Concentration, Muscle, Skeletal chemistry, Rabbits, Cell Membrane physiology, Gadolinium DTPA pharmacology, Magnetic Resonance Spectroscopy, Muscle, Skeletal ultrastructure, Postmortem Changes
- Abstract
The effect of Gd-DTPA on the development in NMR relaxation of skeletal rabbit muscles post-mortem was investigated by dynamic low-field (0.47 T) relaxation measurements from 4 min post-mortem and until 23 h post-mortem. Twelve rabbits were included in the study, and half of the animals were administered 0.2 mmol of Gd-DTPA iv 15 min before sacrifice, while the other half was administered an isotonic salt solution. A significant effect of Gd-DTPA treatment corresponding to a 25% reduction in the T(1) relaxation time was observed. T(2) relaxation was decomposed into two components reflecting intra- and extracellular components (T(2)()alpha and T(2)()beta, respectively), and Gd-DTPA treatment was found to affect both components. However, around 150 min post-mortem a dramatic increase in the difference between control and Gd-DTPA-treated rabbits was observed in the relaxation time of the intracellular water population (T(2)()alpha). Electrical stimulation of the muscles resulted in a significantly earlier onset of the increased effect of Gd-DTPA on the T(2)()alpha population. The increased effect of Gd-DTPA treatment on the T(2)()alpha component is believed to reflect leakage of water from the muscle cells due to membrane destabilization, known to be promoted by electrical stimulation. Accordingly, the present study demonstrates how Gd-DTPA can be used for probing membrane integrity in post-mortem muscles known to be of importance for subsequent water distribution and final water-holding capacity.
- Published
- 2004
- Full Text
- View/download PDF
42. Identification of specific oxidatively modified proteins in chicken muscles using a combined immunologic and proteomic approach.
- Author
-
Stagsted J, Bendixen E, and Andersen HJ
- Subjects
- Animals, Electrophoresis, Gel, Two-Dimensional, Female, Immunoblotting, Oxidation-Reduction, Peptide Mapping, Solubility, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Chickens, Muscle Proteins analysis, Muscle Proteins chemistry, Muscles chemistry, Oxidative Stress, Proteomics
- Abstract
Muscle proteins are generally believed to be key players in free radical processes that eventually lead to oxidative deterioration or modifications of meat proteins resulting in alterations in functionality, for example, gel-forming ability, emulsification properties, and water-binding capacity. This study addresses protein oxidation in chicken muscles using a combined immunologic and proteomic approach and identifies specific proteins that contain carbonyls and/or 3-nitrotyrosine (3-NT). Whereas alpha-enolase was the predominant carbonyl-reactive species among the water-soluble muscle proteins, several other proteins (actin, heat shock protein 70, and creatine kinase) contained carbonyls and/or 3-nitrotyrosine. Finally, this approach was used to demonstrate differential susceptibility of water-soluble muscle proteins toward oxidation in chickens fed a low-antioxidant diet compared with chickens fed a diet supplemented with antioxidant-rich fruits/vegetables.
- Published
- 2004
- Full Text
- View/download PDF
43. The 6-a-day study: effects of fruit and vegetables on markers of oxidative stress and antioxidative defense in healthy nonsmokers.
- Author
-
Dragsted LO, Pedersen A, Hermetter A, Basu S, Hansen M, Haren GR, Kall M, Breinholt V, Castenmiller JJ, Stagsted J, Jakobsen J, Skibsted L, Rasmussen SE, Loft S, and Sandström B
- Subjects
- Adult, Female, Humans, Male, Vitamins blood, Antioxidants metabolism, Diet, Enzyme Induction, Fruit, Minerals administration & dosage, Oxidative Stress, Vegetables, Vitamins administration & dosage
- Abstract
Background: Fruit and vegetables contain both nutritive and nonnutritive factors that might contribute to redox (antioxidant and prooxidant) actions., Objective: We investigated the relative influence of nutritive and nonnutritive factors in fruit and vegetables on oxidative damage and enzymatic defense., Design: A 25-d intervention study with complete control of dietary intake was performed in 43 healthy male and female nonsmokers who were randomly assigned to 1 of 3 groups. In addition to a basic diet devoid of fruit and vegetables, the fruit and vegetables (Fruveg) group received 600 g fruit and vegetables/d; the placebo group received a placebo pill, and the supplement group received a vitamin pill designed to contain vitamins and minerals corresponding to those in 600 g fruit and vegetables. Biomarkers of oxidative damage to protein and lipids and of antioxidant nutrients and defense enzymes were determined before and during intervention., Results: Plasma lipid oxidation lag times increased during intervention in the Fruveg and supplement groups, and the increase was significantly higher in the former. Plasma protein carbonyl formation at lysine residues also increased in both of these groups. Glutathione peroxidase activity increased in the Fruveg group only. Other markers of oxidative damage, oxidative capacity, or antioxidant defense were largely unaffected by the intervention., Conclusions: Fruit and vegetables increase erythrocyte glutathione peroxidase activity and resistance of plasma lipoproteins to oxidation more efficiently than do the vitamins and minerals that fruit and vegetables are known to contain. Plasma protein carbonyl formation at lysine residues increases because of the vitamins and minerals in fruit and vegetables.
- Published
- 2004
- Full Text
- View/download PDF
44. Significance of preslaughter stress and different tissue PUFA levels on the oxidative status and stability of porcine muscle and meat.
- Author
-
Young JF, Rosenvold K, Stagsted J, Steffensen CL, Nielsen JH, and Andersen HJ
- Subjects
- Animals, Catalase metabolism, Diet, L-Lactate Dehydrogenase blood, Lipid Peroxidation, Oxidation-Reduction, Physical Exertion, Stress, Physiological metabolism, Thiobarbituric Acid Reactive Substances analysis, alpha-Tocopherol analysis, Antioxidants analysis, Fatty Acids, Unsaturated analysis, Meat analysis, Muscle, Skeletal chemistry, Stress, Physiological veterinary, Swine
- Abstract
Polyunsaturated fatty acids (PUFAs) and exercise-induced stress are known to increase the oxidative susceptibility of lipids in muscle tissue. In contrast, antioxidative enzymes, e.g., catalase, superoxide dismutase, and glutathione peroxidase, are known to help sustain the delicate oxidative balance in biological tissue upon the application of stressors. The present study investigates the combined effect of different diet-induced muscle PUFA contents and preslaughter stress on the activity of antioxidative muscle enzymes and the oxidative stability of cooked meat. An increased content of unsaturated fatty acids in the tissue led to a decreased activity of lactate dehydrogenase in the plasma, indicating increased cell integrity. Catalase activity in the muscle tissue increased with increasing PUFA levels. However, this upregulation in antioxidative status of the muscle could not counteract the subsequent development of accelerated lipid oxidation in cooked meat as measured in terms of thiobarbituric acid reactive substances. Moreover, preslaughter stress induced increasing oxidative changes with elevated PUFA levels in the muscle tissue.
- Published
- 2003
- Full Text
- View/download PDF
45. Chicken model for studying dietary antioxidants reveals that apple (Cox's Orange)/broccoli (Brassica oleracea L. var. italica) stabilizes erythrocytes and reduces oxidation of insoluble muscle proteins and lipids in cooked liver.
- Author
-
Young JF, Steffensen CL, Nielsen JH, Jensen SK, and Stagsted J
- Subjects
- Animals, Antioxidants analysis, Chickens, Erythrocytes chemistry, Thiobarbituric Acid Reactive Substances analysis, Vitamin E analysis, Vitamin E blood, Antioxidants pharmacology, Brassica chemistry, Diet, Erythrocytes drug effects, Lipid Peroxidation drug effects, Liver chemistry, Malus chemistry, Muscle Proteins metabolism
- Abstract
A chicken model for studying the effects of antioxidants in the diet on oxidative status was set up. Chickens fed a semi-synthetic diet low in antioxidants showed a remarkable decrease in erythrocyte stability toward H(2)O(2) or 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH), but increases in catalase activity in liver, carbonyls in insoluble muscle proteins, and enhanced lipid oxidation in heat-treated liver samples compared to that of conventionally fed chickens. Thus, this chicken model proved to be more susceptible to oxidative changes than conventionally fed chickens, reflecting a low antioxidative defense. Supplementing this low antioxidant diet with 10% apple/broccoli mixture counteracted these changes, except for activity of catalase in the liver and AAPH-induced lysis of erythrocytes. Supplementation with 10% sweet corn only reduced the carbonyl content in insoluble proteins. However, neither low antioxidant diet nor vegetable supplements affected selected antioxidative enzymes or oxidative stability of lipids in heat-treated muscle tissue.
- Published
- 2002
- Full Text
- View/download PDF
46. Large differences in erythrocyte stability between species reflect different antioxidative defense mechanisms.
- Author
-
Stagsted J and Young JF
- Subjects
- Amidines pharmacology, Animals, Birds, Catalase metabolism, Cats, Cattle, Chickens, Erythrocyte Membrane drug effects, Erythrocyte Membrane enzymology, Hemoglobins metabolism, Humans, Hydrogen Peroxide pharmacology, L-Lactate Dehydrogenase metabolism, Rabbits, Species Specificity, Swine, Antioxidants metabolism, Erythrocytes physiology, Oxidative Stress physiology
- Abstract
We have developed a screening assay for erythrocyte stability, which is rapid, easy, inexpensive, robust, and suitable for handling a large number of samples in parallel. Erythrocytes are incubated overnight in 96-well microtiter plates in absence or presence of various oxidants, intact cells are pelleted by centrifugation, and lysis is determined by release of intracellular constituents into the supernatant as either activity of lactate dehydrogenase (LDH) or absorbance of hemoglobin at 406 nm. There is good correlation between the methods. A number of advantages by the present method are that only small amounts of blood is needed, washing is optional, erythrocytes may be stored for at least one day before assay, and large numbers of samples can be handled in parallel. Using this set-up, we have compared erythrocyte stability from several different animal species. We find that erythrocyte susceptibility towards lysis induced by H2O2 and 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) is highly species dependent. The different susceptibility between species is due to cellular components, since swapping of plasma between species has little or no effect. As a novel observation, we find that erythrocytes from chicken are the most sensitive of the species tested towards lysis by H2O2 and are almost four orders of magnitude more sensitive than erythrocytes from man. This is due to a much lower content of catalase in erythrocytes from chicken. A more narrow range is observed for susceptibility towards AAPH and the ranking between the species is different. Thus, chicken erythrocytes are more resistant towards AAPH than some mammals by up to two orders of magnitude. This differential stability towards different oxidative stressors is likely due to evolution/selection of different defense mechanisms.
- Published
- 2002
- Full Text
- View/download PDF
47. Sensory colour assessment of fresh meat from pigs supplemented with iron and vitamin E.
- Author
-
O'Sullivan MG, Byrne DV, Stagsted J, Andersen HJ, and Martens M
- Abstract
Pork muscle samples (M. longissimus dorsi) were obtained from pigs given one of four dietary treatments: (1) control diet; (2) supplemental iron [7-g iron (II) sulphate/kg feed]; (3) supplemental vitamin E (200-mg dl-α-tocopheryl acetate/kg of feed); and (4) supplemental vitamin E+supplemental iron. Muscle cores were packaged in polythene bags and placed in a retail refrigerated display cabinet at 5±1°C, under fluorescent light (1000 LUX) for up to 5 days. Samples were subjected to visual colour evaluation by a trained sensory panel (n=12) at 0, 1, 3 and 5 days. In addition instrumental L*, a* and b* values and drip loss were measured on each day of analysis. All samples became less red and browner over storage time in the refrigerated display cabinet. The vitamin E treated samples were more red and less brown compared with the other samples on successive days in the cabinet followed by the control, iron/vitamin E and iron treatments. The iron/vitamin E treatment was positioned midway between the vitamin E and iron treatments indicating that the vitamin E in the samples was effective in reducing the pro-oxidative effect of iron in inducing the brown metmyoglobin pigment development. Iron supplementation did not significantly (P<0.05) increase M. longissimus dorsi iron tissue levels, but had a detrimental effect on the visual sensory properties of the iron and iron/vitamin E treatment groups with greater metmyoglobin formation. Vitamin E appears to have promoted non-supplemental iron absorption in the vitamin E treated group without the detrimental sensory colour characteristics associated with ferrous sulphate supplementation. Drip loss increased in all samples during the course of the experiment with no significant (P<0.05) differences between the experimental groups. The panellists were able to differentiate the four experimental groups on each day of the study and were more effective in evaluating the colour quality of samples than instrumental assessment, i.e. the Hunter L* a* b* method.
- Published
- 2002
- Full Text
- View/download PDF
48. Journey beyond immunology. Regulation of receptor internalization by major histocompatibility complex class I (MHC-I) and effect of peptides derived from MHC-I.
- Author
-
Stagsted J
- Subjects
- Animals, Cell Membrane physiology, HLA-D Antigens chemistry, HLA-D Antigens immunology, Histocompatibility Antigens Class I chemistry, Histocompatibility Antigens Class II chemistry, Histocompatibility Antigens Class II immunology, Humans, Models, Molecular, Molecular Chaperones physiology, Peptide Fragments chemical synthesis, Peptide Fragments chemistry, Protein Conformation, Genes, MHC Class I, Histocompatibility Antigens Class I immunology, Monosaccharide Transport Proteins metabolism, Peptide Fragments pharmacology, Receptor, Insulin physiology
- Published
- 1998
49. Beta-sheet models for the ordered filamentous structure formed by a peptide that enhances the action of insulin.
- Author
-
Weaver L, Stagsted J, Behnke O, Matthews BW, and Olsson L
- Subjects
- Amino Acid Sequence, Drug Synergism, In Vitro Techniques, Microscopy, Electron, Models, Molecular, Molecular Sequence Data, Molecular Structure, Protein Structure, Secondary, X-Ray Diffraction, Insulin pharmacology, Peptides chemistry, Peptides pharmacology
- Abstract
Certain peptides with sequences related to part of the major histocompatibility complex class I antigen enhance the action of insulin. These peptides also aggregate into fibrous structures that seem to be related to their biological activity. In the current study, the 17-residue peptide with amino acid sequence Gly-Asn-Glu-Gln-Ser-Phe-Arg-Val-Asp-Leu-Arg-Thr-Leu-Leu-Arg-Tyr-Ala is used as a representative example of these bioactive molecules. As seen by electron microscopy, the peptide associates into gently twisted ribbons, 50 A thick, in which the amount of twist decreases as the ribbons become wider. X-ray diffraction analysis suggests that the peptides are arranged as in an antiparallel beta-sheet extending essentially endlessly along the fiber axis. The amino acid sequence of the peptide is such that one side of the beta-sheet is predominantly polar while the opposite side is nonpolar. This allows the beta-sheets to form multilayers with alternating hydrophobic and hydrophilic interfaces. The length of the extended peptide (approximately 54 A) determines the thickness of the ribbon and the tendency of individual beta-sheets to twist accounts for the twisting of the ribbons. An alternative model is also discussed, again based on antiparallel beta-sheets, but with adjacent sheets interdigitated in a "side-by-side" fashion rather than forming stacked layers. Comparable inactive peptides such as Gly-Asn-Glu-Gln-Ser-Ala-Arg-Val-Asp-Leu-Arg-Thr-Leu-Leu-Arg-Tyr-Tyr (changed amino acids underlined) do not form ordered filamentous structures.
- Published
- 1996
- Full Text
- View/download PDF
50. Regulation of insulin receptor functions by a peptide derived from a major histocompatibility complex class I antigen.
- Author
-
Stagsted J, Reaven GM, Hansen T, Goldstein A, and Olsson L
- Subjects
- Amino Acid Sequence, Animals, Blood Glucose metabolism, Endocytosis, Glucose metabolism, Insulin physiology, Molecular Sequence Data, Monosaccharide Transport Proteins metabolism, Peptide Fragments chemical synthesis, Rats, Rats, Inbred Strains, Structure-Activity Relationship, H-2 Antigens physiology, Receptor, Insulin physiology
- Abstract
A 25 residue peptide, Dk-(61-85), derived from the alpha 1 domain of a murine MHC class I molecule (H-2Dk), enhances cellular glucose uptake, prolongs the effect of insulin, and inhibits insulin receptor internalization without affecting insulin binding or dissociation. Full effect of the peptide is obtained at 10-100 microM. The magnitude of the peptide-mediated enhancement of glucose uptake is insulin dependent and is at maximum approximately 50% above that of full insulin stimulation, excluding a merely insulinomimetic action of the peptide. Dk-(61-85) does not interact directly with the glucose transporter molecule. Furthermore, the peptide-mediated inhibition of insulin receptor internalization results in 2-3 times more receptors in the plasma membrane. The peptide also causes hypoglycemia in rats. The biological activity of Dk-(61-85) suggests that an important nonimmunological role of MHC class I molecules is to affect some of the key functions of ligand-activated receptors.
- Published
- 1990
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.