| 1. |
- Ristilä, Mikael, et al.
(författare)
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The role of the pyridoxine (vitamin B6) biosynthesis enzyme PDX1 in ultraviolet-B radiation responses in plants
- 2011
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Ingår i: Plant physiology and biochemistry (Paris). - Amsterdam : Elsevier. - 0981-9428 .- 1873-2690. ; 49:3, s. 284-292
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Tidskriftsartikel (refereegranskat)abstract
- Ultraviolet-B radiation regulates plant growth and morphology at low and ambient fluence rates but can severely impact on plants at higher doses. Some plant UV-B responses are related to the formation of reactive oxygen species (ROS) and pyridoxine (vitamin B6) has been reported to be a quencher of ROS. UV-B irradiation of Arabidopsis Col-0 plants resulted in increased levels of PDX1 protein, compared with UV-A-exposed plants. This was shown by immunoblot analysis using specific polyclonal antibodies raised against the recombinant PDX1.3 protein and confirmed by mass spectrometry analysis of immunoprecipitated PDX1. The protein was located mainly in the cytosol but also to a small extent in the membrane fraction of plant leaves. Immunohistochemical analysis performed in pea revealed that PDX1 is present in UV-B-exposed leaf mesophyll and palisade parenchyma but not in epidermal cells. Pyridoxine production increased in Col-0 plants exposed to 3 days of UV-B, whereas in an Arabidopsis pdx1.3 mutant UV-B did not induce pyridoxine biosynthesis. In gene expression studies performed after UV-B exposure, the pdx1.3 mutant showed elevated transcript levels for the LHCB1*3 gene (encoding a chlorophyll a/b-binding protein of the photosystem II light-harvesting antenna complex) and the pathogenesis-related protein 5 (PR-5) gene, compared with wild type.
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| 2. |
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| 3. |
- Scherbak, Nikolai, et al.
(författare)
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The pea SAD short-chain dehydrogenase/reductase : quinone reduction, tissue distribution, and heterologous expression
- 2011
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Ingår i: Plant Physiology. - : Oxford University Press (OUP). - 0032-0889 .- 1532-2548. ; 155:4, s. 1839-1850
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Tidskriftsartikel (refereegranskat)abstract
- The pea (Pisum sativum) tetrameric short-chain alcohol dehydrogenase-like protein (SAD) family consists of at least three highly similar members (SAD-A, -B, and -C). According to mRNA data, environmental stimuli induce SAD expression. The aim of this study was to characterize the SAD proteins by examining their catalytic function, distribution in pea, and induction in different tissues. In enzyme activity assays using a range of potential substrates, the SAD-C enzyme was shown to reduce one- or two-ring-membered quinones lacking long hydrophobic hydrocarbon tails. Immunological assays using a specific antiserum against the protein demonstrated that different tissues and cell types contain small amounts of SAD protein that was predominantly located within epidermal or subepidermal cells and around vascular tissue. Particularly high local concentrations were observed in the protoderm of the seed cotyledonary axis. Two bow-shaped rows of cells in the ovary and the placental surface facing the ovule also exhibited considerable SAD staining. Ultraviolet-B irradiation led to increased staining in epidermal and subepidermal cells of leaves and stems. The different localization patterns of SAD suggest functions both in development and in responses to environmental stimuli. Finally, the pea SAD-C promoter was shown to confer heterologous wound-induced expression in Arabidopsis (Arabidopsis thaliana), which confirmed that the inducibility of its expression is regulated at the transcriptional level.
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| 4. |
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| 5. |
- Al-Anati, Lauy, et al.
(författare)
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Hydroxyl metabolite of PCB 180 induces DNA damage signaling and enhances the DNA damaging effect of benzo[a]pyrene
- 2015
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Ingår i: Chemico-Biological Interactions. - : Elsevier. - 0009-2797 .- 1872-7786. ; 239, s. 164-173
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Tidskriftsartikel (refereegranskat)abstract
- Non-dioxin-like (NDL) polychlorinated biphenyls (PCBs) and their hydroxyl metabolites (OH-PCBs) are ubiquitous environmental contaminants in human tissues and blood. The toxicological impact of these metabolites is poorly understood. In this study rats were exposed to ultrapure PCB180 (10-1000 mg/kg bw) for 28 days and induction of genotoxic stress in liver was investigated. DNA damage signaling proteins (pChk1Ser317 and gamma H2AXSer319) were increased dose dependently in female rats. This increase was paralleled by increasing levels of the metabolite 3'-OH-PCB180. pChk1 was the most sensitive marker. In in vitro studies HepG2 cells were exposed to 1 mu M of PCB180 and 3'-OH-PCB180 or the positive control benzo[a]pyrene (BaP, 5 mu M). 3'-OH-PCB180, but not PCB180, induced CYP1A1 mRNA and gamma H2AX. CYP1A1 mRNA induction was seen at 1 h, and gamma H2AX at 3 h. The anti-oxidant N-Acetyl-L-Cysteine (NAC) completely prevented, and 17 beta-estradiol amplified the gamma H2AX induction by 3'-OH-PCB180. As 3'-OH-PCB180 induced CYP1A1, a major BaP-metabolizing and activating enzyme, interactions between 3'-OH-PCB180 and BaP was also studied. The metabolite amplified the DNA damage signaling response to BaP. In conclusion, metabolism of PCB180 to its hydroxyl metabolite and the subsequent induction of CYP1A1 seem important for DNA damage induced by PCB180 in vivo. Amplification of the response with estradiol may explain why DNA damage was only seen in female rats.
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| 6. |
- Andersson, Sören, 1957-, et al.
(författare)
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CHIMERIC MOMP ANTIGEN
- 2015
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Patent (populärvet., debatt m.m.)
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| 7. |
- Andersson, Sören, 1957-, et al.
(författare)
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Chimeric MOMP antigen
- 2014
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Patent (populärvet., debatt m.m.)abstract
- The present invention regards polypeptides capable of eliciting an immunological response that is protective against Chlamydia trachomatis. The polypeptide comprises a first amino acid sequence which has at least 90% homology with the amino acid sequence according to SEQ ID NO: 1 and a second amino acid sequence which has at least 90% homology with the amino acid sequence according to SEQ ID NO: 2. Furthermore, production of these polypeptides and pharmaceutical compositions comprising them are also provided.
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| 8. |
- Asghar, Naveed, 1983-, et al.
(författare)
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Transient Expression of Flavivirus Structural Proteins in Nicotiana benthamiana
- 2022
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Ingår i: Vaccines. - : MDPI. - 2076-393X. ; 10:10
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Tidskriftsartikel (refereegranskat)abstract
- Flaviviruses are a threat to public health and can cause major disease outbreaks. Tick-borne encephalitis (TBE) is caused by a flavivirus, and it is one of the most important causes of viral encephalitis in Europe and is on the rise in Sweden. As there is no antiviral treatment availa-ble, vaccination remains the best protective measure against TBE. Currently available TBE vaccines are based on formalin-inactivated virus produced in cell culture. These vaccines must be delivered by intramuscular injection, have a burdensome immunization schedule, and may exhibit vaccine failure in certain populations. This project aimed to develop an edible TBE vaccine to trigger a stronger immune response through oral delivery of viral antigens to mucosal surfaces. We demonstrated successful expression and post-translational processing of flavivirus structural pro-teins which then self-assembled to form virus-like particles in Nicotiana benthamiana. We performed oral toxicity tests in mice using various plant species as potential bioreactors and evaluated the immunogenicity of the resulting edible vaccine candidate. Mice immunized with the edible vaccine candidate did not survive challenge with TBE virus. Interestingly, immunization of female mice with a commercial TBE vaccine can protect their offspring against TBE virus infection.
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| 9. |
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| 10. |
- Brosché, Mikael, et al.
(författare)
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Gene regulation by low level UV-B radiation : identification by DNA array analysis
- 2002
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Ingår i: Photochemical and Photobiological Sciences. - 1474-905X .- 1474-9092. ; 1:9, s. 656-664
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Tidskriftsartikel (refereegranskat)abstract
- UV-B radiation alters transcript levels of various defence genes and photosynthetic genes in plants. Utilising a DNA array with 5000 ESTs and cDNAs from Arabidopsis thaliana, 70 genes were found to show a greater than two-fold induction or repression of transcript levels. Six genes (MEB5.2, PyroA, Ubq3, Lhcb6, F5D21.10 and the gene for an RNA polymerase II subunit) were tested for stress specific gene regulation on northern blots with RNA from plants exposed to low dose UV-B radiation, ozone or wounding. Transcript levels for PyroA, Uhq3 and the gene for a RNA polymerase II subunit were all specifically increased by UV-B. MEB5.2 mRNA levels also rose, whereas Lhcb6 and FSD21.10 transcript levels decreased under all stresses. The PyroA gene product in fungi is needed for biosynthesis of pyridoxine, and might have a role in protection against singlet oxygen. The Ubq3 gene encodes the ubiquitin protein that is attached to proteins destined for degradation. MEB5.2 and F5D21.10 represent novel gene products whose function have not yet been identified. Pairwise comparisons between the UV-B inducible promoters have identified a series of elements present in the MEB5.2 and PyroA promoters, absent from promoters of genes for early phenylpropanoid metabolism and that may be responsible for modulating their UV-B responses.
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| 11. |
- Brosché, Mikael, et al.
(författare)
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Molecular events following perception of ultraviolet-B radiation by plants
- 2003
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Ingår i: Physiologia Plantarum. - : Wiley. - 0031-9317 .- 1399-3054. ; 117:1, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Exposure of plants to UV-B radiation (280–320 nm) results in changes in expression of a large number of genes. Before UV-B radiation or light of other wavelengths can give rise to a cellular response, it has to be perceived by some kind of receptor, and the information transduced via a signalling pathway to the target molecules, be it proteins in the cytoplasm or the genetic material in the nucleus. The perception of low levels of UV-B probably occurs via a UV-B photoreceptor followed by several different signalling pathways. These pathways include second messengers such as calcium, kinases and the catalytic formation of reactive oxygen species. High levels of UV-B, on the other hand, probably cause cellular damage and oxidative stress, thus activating a general stress signal transduction pathway which leads to a response similar to that which occurs after pathogen attack and other stresses. Some of the genes identified so far as being regulated by UV-B encode proteins involved in the biosynthesis of protective pigments, DNA repair and antioxidative enzymes, photosynthetic genes, cell cycle genes, and stress genes induced by other types of stimuli (i.e. pathogenesis-related proteins and senescence-induced genes). In the light of the information obtained on components necessary for UV-B-induced changes in gene expression, we propose in this mini-review a working model for UV-B perception and signal transduction. This model also takes into account dosage differences for the observations, which imply a separation into UV-B-specific and more general stress signal transduction.
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| 12. |
- Castro Alves, Victor, 1986-, et al.
(författare)
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Integration of non-target metabolomics and sensory analysis unravels vegetable plant metabolite signatures associated with sensory quality : A case study using dill (Anethum graveolens)
- 2021
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Ingår i: Food Chemistry. - : Elsevier. - 0308-8146 .- 1873-7072. ; 344
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Tidskriftsartikel (refereegranskat)abstract
- Using dill (Anethum graveolens L.) as a model herb, we revealnovel associations between metabolite profile and sensory quality, by integrating non-target metabolomics with sensory data. Low night temperatures and exposure to UV-enriched light was used to modulate plant metabolism, thereby improving sensory quality. Plant age is a crucial factor associated with accumulation of dill ether and α-phellandrene, volatile compounds associated with dill flavour. However, sensory analysis showed that neither of these compounds has any strong association with dill taste. Rather, amino acids alanine, phenylalanine, glutamic acid, valine, and leucine increased in samples exposed to eustress and were positively associated with dill and sour taste. Increases in amino acids and organic acids changed the taste from lemon/grass to a more bitter/pungent dill-related taste. Our approach reveals a novel approach to establish links between effects of eustressors on sensory quality, and may be applicable to a broad range of crops.
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| 13. |
- Castro Alves, Victor, 1986-, et al.
(författare)
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The taste of UV light : Using sensomics to improve horticultural quality
- 2020
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Ingår i: UV4Plants Bulletin. - Helsingfors : University of Helsinki. - 2343-323X. ; :1, s. 39-43
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Tidskriftsartikel (refereegranskat)abstract
- Greenhouse horticulture is in its broad definition the production of plant products within, under or sheltered by structures that provide protection against biotic and/or abiotic stress. In greenhouses, horticultural crops can grow protected from infectious agents and adverse weather conditions, allowing off-season, year-round production. However, greenhouse production often comes with a trade-off, which is a skewed light environment with a lack of UV light. In some instances, the blockage of UV by greenhouse glass and plastic covers is beneficial from a commercial perspective, especially on tropical latitudes where plants can often encounter higher UV levels, which may impair plant growth and nutrient absorption (Krause et al. 1999; Verdaguer et al. 2017). On the other hand, reduced UV inside greenhouses may reduce the synthesis of metabolites associated with crop protection against biotic and abiotic stress, such as flavonoids, terpenoids and alkaloids (Yang et al. 2018). This reduction in the amount of protective compounds may not be seen as an important limitation in a protected environment, but these metabolic changes caused by reduced UV exposure may in fact negatively impact on product quality. For example, it is possible to improve of the aroma and taste of greenhouse tomato by exposing plants to low levels of supplementary UV light (Dzakovich et al. 2016).
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| 14. |
- Chow, Wah Soon, et al.
(författare)
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A tribute to Robert John Porra (august 7, 1931–may 16, 2019)
- 2021
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Ingår i: Photosynthesis Research. - : Springer Nature. - 0166-8595 .- 1573-5079. ; 147:2, s. 125-130
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Tidskriftsartikel (refereegranskat)abstract
- Robert John Porra (7.8.1931–16.5.2019) is probably best known for his substantial practical contributions to plant physiology and photosynthesis by addressing the problems of both the accurate spectroscopic estimation and the extractability of chlorophylls in many organisms. Physiological data and global productivity estimates, in particular of marine primary productivity, are often quoted on a chlorophyll basis. He also made his impact by work on all stages of tetrapyrrole biosynthesis: he proved the C5 pathway to chlorophylls, detected an alternative route to protoporphyrin in anaerobes and the different origin of the oxygen atoms in anaerobes and aerobes. A brief review of his work is supplemented by personal memories of the authors.
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| 15. |
- Comont, David, et al.
(författare)
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Exploring latitudinal variation in UV radiation and climate : impacts on a model grass system
- 2011
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Ingår i: Abstracts of the 1st Annual Meeting of COST Action FA0906 UV4growth. - Szeged : Biological Research Center of the Hungarian Academy of Sciences. - 9789635086061 ; , s. 14-14
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Konferensbidrag (refereegranskat)abstract
- Perennial ryegrass (Lolium perenne) seedlings were grown at 14 European locations across a latitudinal gradient spanning 37 to 68°N. Seedlings planted in nutrient enriched vermiculite were grown outdoors over five weeks between the 29th June and the 3rd August 2010. At each location there were three treatments – open, filtered with cellulose acetate (UV transparent) and filtered with Mylar (UV opaque). Plants were regularly watered and outdoor climatic conditions were monitored at nearby meteorological stations. The aim of the experiment was to assess the significance of ambient UV radiation to L.perenne, both at each location and across the gradient in terms of aboveground biomass, tiller number, and the level of UV protective plant pigments. Material was further screened using metabolite fingerprinting (FT-IR spectroscopy) to assess local, regional and latitudinal variation in total plant chemistry. Data presented will explore and interpret the complex variations in growth and chemistry looking at local responses and the latitudinal gradient explored.
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| 16. |
- Comont, David, et al.
(författare)
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UV responses of Lolium perenne raised along a latitudinal gradient across Europe : a filtration study
- 2012
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Ingår i: Physiologia Plantarum. - : Wiley-Blackwell. - 0031-9317 .- 1399-3054. ; 145, s. 604-618
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Tidskriftsartikel (refereegranskat)abstract
- Lolium perenne (cv. AberDart) was grown at 14 locations along a latitudinal gradient across Europe (37–68◦N) to study the impact of ultraviolet radiation (UV) and climate on aboveground growth and foliar UV-B absorbing compounds. At each location, plants were grown outdoors for 5 weeks in a replicated UV-B filtration experiment consisting of open, UV-B transparent (cellulose diacetate) and UV-B opaque (polyester) environments. Fourier transform-infrared spectroscopy was used to compare plantmetabolite profiles in relation to treatment and location. UV radiation and climatic parameters were determined for each location from online sources and the data were assessed using a combination of ANOVA and multiple regression analyses. Most of the variation in growth between the locations was attributable to the combination of climatic parameters, with minimum temperature identified as an important growth constraint. However, no single environmental parameter could consistently account for the variability in plant growth. Concentrations of foliar UV-B absorbing compounds showed a positive trend with solar UV across the latitudinal gradient; however, this relationship was not consistent in all treatments. The most striking experimental outcome from this study was the effect of presence or absence of filtration frames onUV-absorbing compounds. Overall, the study demonstrates the value of an European approach in studying the impacts of natural UV across a large latitudinal gradient. We have shown the feasibility of coordinated UV filtration at multiple sites but have also highlighted the need for open controls and careful interpretation of plant responses.
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| 17. |
- Czegeny, G., et al.
(författare)
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Hydrogen peroxide contributes to the ultraviolet-B (280-315 nm) induced oxidative stress of plant leaves through multiple pathways
- 2014
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Ingår i: Febs Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 588:14, s. 2255-2261
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Tidskriftsartikel (refereegranskat)abstract
- Solar UV-B (280-315 nm) radiation is a developmental signal in plants but may also cause oxidative stress when combined with other environmental factors. Using computer modeling and in solution experiments we show that UV-B is capable of photosensitizing hydroxyl radical production from hydrogen peroxide. We present evidence that the oxidative effect of UV-B in leaves is at least twofold: (i) it increases cellular hydrogen peroxide concentrations, to a larger extent in pyridoxine antioxidant mutant pdx1.3-1 Arabidopsis and; (ii) is capable of a partial photo-conversion of both 'natural' and 'extra' hydrogen peroxide to hydroxyl radicals. As stress conditions other than UV can increase cellular hydrogen peroxide levels, synergistic deleterious effects of various stresses may be expected already under ambient solar UV-B. (C) 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
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| 18. |
- Czégény, Gyula, et al.
(författare)
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Multiple roles for Vitamin B6in plant acclimation to UV-B
- 2019
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Direct and indirect roles of vitamin B6in leaf acclimation to supplementary UV-B radiation are shown in vitamin B6deficient Arabidopsis thalianamutant rsr4-1 and C24 wild type. Responses to 4 days of 3.9 kJ m-2d-1 biologically effective UV-B dose were compared in terms of leaf photochemistry, vitamer content, and antioxidant enzyme activities; complemented with a comprehensive study of vitamer ROS scavenging capacities. Under UV-B, rsr4-1 leaves lost more (34%) photochemical yield than C24 plants (24%). In the absence of UV-B, rsr4-1 leaves contained markedly less pyridoxal-5’-phosphate (PLP) than C24 ones, but levels increased up to the C24 contents in response to UV-B. Activities of class-III ascorbate and glutathione peroxidases increased in C24 leaves upon the UV-B treatment but not in the rsr4-1 mutant. SOD activities remained the same in C24 but decreased by more than 50% in rsr4-1 under UV-B. Although PLP was shown to be an excellent antioxidant in vitro, our results suggest that the UV-B protective role of B6 vitamers is realized indirectly, via supporting peroxidase defence rather than by direct ROS scavenging. We hypothesize that the two defence pathways are linked through the PLP-dependent biosynthesis of cystein and heme, affecting peroxidases.
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| 19. |
- Díaz-Ramos, L. Aranzazú, et al.
(författare)
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Difference in the action spectra for UVR8 monomerisation and HY5 transcript accumulation in Arabidopsis
- 2018
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Ingår i: Photochemical and Photobiological Sciences. - : Royal Society of Chemistry. - 1474-905X .- 1474-9092. ; 17:8, s. 1108-1117
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Tidskriftsartikel (refereegranskat)abstract
- The photoreceptor UV RESISTANCE LOCUS 8 (UVR8) activates photomorphogenic responses when plants are exposed to ultraviolet-B (UVB) light. However, whereas the absorption spectrum of UVR8 peaks at 280 nm, action spectra for several photomorphogenic UV-B responses show maximal photon effectiveness at 290-300 nm. To investigate this apparent discrepancy we measured the effectiveness of UV wavelengths in initiating two responses in Arabidopsis: photoconversion of homodimeric UVR8 into the monomeric form, which is active in signaling, and accumulation of transcripts of the ELONGATED HYPOCOTYL 5 (HY5) transcription factor, which has a key role in UVR8-mediated responses. When purified UVR8 or Arabidopsis leaf extracts were exposed to UV light monomerisation was maximal at approximately 280 nm, which correlates with the UVR8 absorption spectrum. When intact plants were exposed to UV, monomerisation was most strongly initiated at approximately 290 nm, and this shift in maximal effectiveness could be explained by strong absorption or reflectance at 280 nm by leaf tissue. Notably, the action spectrum for accumulation of HY5 transcripts in the same leaf tissue samples used to assay UVR8 dimer/monomer status peaked at approximately 300 nm. Possible reasons for the difference in maximal photon effectiveness of UVR8 monomerisation and HY5 transcript accumulation in leaf tissue are discussed.
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| 20. |
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| 21. |
- Elmabsout, Ali Ateia, et al.
(författare)
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Cloning and Functional Studies of a Splice Variant of CYP26B1 Expressed in Vascular Cells
- 2012
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Ingår i: Plos One. - San Francisco, USA : Public Library of Science (PLoS). - 1932-6203. ; 7:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: All-trans retinoic acid (atRA) plays an essential role in the regulation of gene expression, cell growth and differentiation and is also important for normal cardiovascular development but may in turn be involved in cardiovascular diseases, i.e. atherosclerosis and restenosis. The cellular atRA levels are under strict control involving several cytochromes P450 isoforms (CYPs). CYP26 may be the most important regulator of atRA catabolism in vascular cells. The present study describes the molecular cloning, characterization and function of atRA-induced expression of a spliced variant of the CYP26B1 gene. Methodology/Principal Findings: The coding region of the spliced CYP26B1 lacking exon 2 was amplified from cDNA synthesized from atRA-treated human aortic smooth muscle cells and sequenced. Both the spliced variant and full length CYP26B1 was found to be expressed in cultured human endothelial and smooth muscle cells, and in normal and atherosclerotic vessel. atRA induced both variants of CYP26B1 in cultured vascular cells. Furthermore, the levels of spliced mRNA transcript were 4.5 times higher in the atherosclerotic lesion compared to normal arteries and the expression in the lesions was increased 20-fold upon atRA treatment. The spliced CYP26B1 still has the capability to degrade atRA, but at an initial rate one-third that of the corresponding full length enzyme. Transfection of COS-1 and THP-1 cells with the CYP26B1 spliced variant indicated either an increase or a decrease in the catabolism of atRA, probably depending on the expression of other atRA catabolizing enzymes in the cells. Conclusions/Significance: Vascular cells express the spliced variant of CYP26B1 lacking exon 2 and it is also increased in atherosclerotic lesions. The spliced variant displays a slower and reduced degradation of atRA as compared to the full-length enzyme. Further studies are needed, however, to clarify the substrate specificity and role of the CYP26B1 splice variant in health and disease.
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| 22. |
- Elmabsout, Ali, et al.
(författare)
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Cloning and functional studies of a splice variant of CYP26B1 : a cellular storage protein for all-trans retinoic acid
- 2010
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Ingår i: In Vivo. - 0258-851X .- 1791-7549. ; 24:3, s. 345-346
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAll-trans retinoic acid (atRA) plays an essential role in the regulation of gene expression, cell growth and differentiation and is also important for normal cardiovascular development but may in turn be involved in cardiovascular diseases, i.e. atherosclerosis and restenosis. The cellular atRA levels are under strict control involving several cytochromes P450 isoforms (CYPs). CYP26 may be the most important regulator of atRA catabolism in vascular cells. The present study describes the molecular cloning, characterization and function of atRA-induced expression of a spliced variant of the CYP26B1 gene.Methodology/Principal FindingsThe coding region of the spliced CYP26B1 lacking exon 2 was amplified from cDNA synthesized from atRA-treated human aortic smooth muscle cells and sequenced. Both the spliced variant and full length CYP26B1 was found to be expressed in cultured human endothelial and smooth muscle cells, and in normal and atherosclerotic vessel. atRA induced both variants of CYP26B1 in cultured vascular cells. Furthermore, the levels of spliced mRNA transcript were 4.5 times higher in the atherosclerotic lesion compared to normal arteries and the expression in the lesions was increased 20-fold upon atRA treatment. The spliced CYP26B1 still has the capability to degrade atRA, but at an initial rate one-third that of the corresponding full length enzyme. Transfection of COS-1 and THP-1 cells with the CYP26B1 spliced variant indicated either an increase or a decrease in the catabolism of atRA, probably depending on the expression of other atRA catabolizing enzymes in the cells.Conclusions/SignificanceVascular cells express the spliced variant of CYP26B1 lacking exon 2 and it is also increased in atherosclerotic lesions. The spliced variant displays a slower and reduced degradation of atRA as compared to the full-length enzyme. Further studies are needed, however, to clarify the substrate specificity and role of the CYP26B1 splice variant in health and disease.
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| 23. |
- Enroth, Cristofer, et al.
(författare)
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Crystal structure of a protein, structurally related to glycosyltransferases, encoded in the Rhodobacter blasticus atp operon
- 2008
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Ingår i: Biochimica et Biophysica Acta - Proteins and Proteomics. - Amsterdam : Elsevier/North Holland. - 1570-9639 .- 1878-1454. ; 1784:2, s. 379-384
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Tidskriftsartikel (refereegranskat)abstract
- The F1-ATP synthase atp operon in the proteobacterium Rhodobacter blasticus contains six open reading frames, encoding six hypothetical proteins. Five of these subunits, in the stoichiometry (ab)3gde make up the catalytic F1-ATP synthase complex similarly in bacteria, chloroplasts and mitochondria. The sixth gene of the Rb. blasticus atp operon, urf6, shows very little sequence homology to any protein of known structure or function. The gene has previously been cloned, the product (called majastridin) has been heterologously expressed in Escherichia coli, and purified to high homogeneity (Brosché et al. (1998) Eur. J. Biochem. 255: 87-92). We have solved the X-ray crystal structure and refined a model of majastridin to atomic resolution. Here we present the crystal structures of apo-majastridin and the complex of majastridin with Mn2+ and UDP and show it has extensive structural similarity to glycosyltransferases (EC 2.4). This is the first structure determined from a new group of distantly related bacterial proteins of at least six members. They share the identical amino acids that bind Mn2+and a triplet of amino acids in the putative sugar-binding site.
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| 24. |
- Eriksson, Carl, 1981-, et al.
(författare)
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Clinical effectiveness of golimumab in ulcerative colitis : a prospective multicentre study based on the Swedish IBD Quality Register, SWIBREG
- 2021
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 56:11, s. 1304-1311
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Clinical trials demonstrated that golimumab is effective in anti-TNF naïve patients with ulcerative colitis. We aimed to assess the clinical effectiveness of golimumab in a real-world setting. Materials and methods: This was a prospective cohort study, conducted at 16 Swedish hospitals. Data were collected using an electronic case report form. Patients with active ulcerative colitis, defined as Mayo endoscopic subscore ≥2 were eligible for inclusion. The primary outcomes were clinical effectiveness at 12 weeks and 52 weeks, i.e. response (defined as a decrease in Mayo score by ≥3 points or 30% from baseline) and remission (defined as a Mayo score of ≤2 with no individual subscores >1). Results: Fifty patients were included. At study entry, 70% were previously exposed to anti-TNF, 16% to vedolizumab, and 96% to immunomodulators. The 12 and 52-week drug continuation rates were 37/50 (74%) and 23/50 (46%), respectively. The 12-week response rate was 14/50 (28%), the remission rate, 8/50 (16%) and the corresponding figures at week 52 were 13/50 (26%) and 10/50 (20%). Among patients who continued golimumab, the median Mayo score decreased from 7 (6–9) at baseline to 1 (0–5) at 52 weeks (p <.01) and the faecal calprotectin decreased from 862 (335–1759) µg/g to 90 (34–169) µg/g (p <.01). Clinical response at week 12 was highly predictive of clinical remission at week 52 (adjusted OR: 73.1; 95% CI: 4.5‒1188.9). Conclusions: The majority of golimumab treated patients represented a treatment refractory patient-group. Despite this, our results confirm that golimumab is an effective therapy in ulcerative colitis.
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| 25. |
- Eriksson, Leif A., et al.
(författare)
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Chemistry of vitamin B6 under oxidative stress
- 2012
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Ingår i: UV4growth COST-Action FA0906. - Köpenhamn : University of Copenhagen. ; , s. 28-28
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Konferensbidrag (refereegranskat)abstract
- Vitamin B6, or pyridoxine, is the precursor of the biologically active derivatives pyridoxal-5’-phosphate and pyridoxamine-5’-phosphate (Fig.1), with functional roles in a number of different enzymes. Pyridoxine itself is a cofactor of several enzymes that catalyze decarboxylations, transaminations, and racemations of amino acids. Bacteria, fungi, and plants produce their own vitamin B6, whereas parasitic organisms and higher animals have to acquire vitamin B6 through nutrient intake.Lately, pyridoxine biosynthesis-deficient mutants of fungi and yeast have been shown to be sensitive to reactive oxygen species (ROS) such as singlet oxygen and hydrogen peroxide. This suggests that vitamin B6 and its derivatives are also involved in stress tolerance in living organisms, especially in alleviating oxidative stress. In eukaryotes, stress resistance has been implied to involve pyridoxine-dependent singlet oxygen quenching, whereby the pyridoxine itself would react with and quench the singlet oxygen. The oxidative stress-protective effect of pyridoxine has also been described both in red blood cells and in lens cells in animals. Pyridoxine itself was found to be the most effective of the vitamin B6 species, twice as effective as pyridoxal-5’-phosphate, and as effective as vitamin E. Knowledge about this novel mechanism of reaction between pyridoxine or its derivatives (cf. Figure 1) and singlet oxygen and other ROS is however very limited. However, since both the aldehyde (pyridoxal) and the amino (pyridoxamine) derivatives only to a small extent influence the rate of reaction, these moieties are probably not involved. Also, since the heteroaromatic absorbance peak at 323 nm disappears during the reaction, at least one of the targets for singlet oxygen is most likely the core of the aromatic ring, leading to ring opening.In order to shed more light on the possible role of pyridoxine in stress tolerance / protection we herein report on computational studies of possible reaction mechanisms between pyridoxine and different ROS (singlet oxygen, superoxide and hydrogen peroxide) by means of density functional theory (DFT) based methods. It is concluded that the compound has an extremely high quenching power towards hydroxyl radicals. We furthermore explore the explicit UV-induced photolysis pathways of the compound, as well as enzymatic degradation (ring-opening) by bacterial flavoprotein monooxygenases.
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| 26. |
- Eriksson, Leif A., 1964-, et al.
(författare)
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Tetrazole derivatives as cytochrome p450 inhibitors
- 2019
-
Patent (populärvet., debatt m.m.)abstract
- According to the invention there is provided a compound of formula I, wherein R1 and R2 have meanings given in the description, which compounds are useful in the treatment of skin disorders and other diseases.
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| 27. |
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| 28. |
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| 29. |
- Fängström, Britta, et al.
(författare)
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A retrospective study of PBDEs and PCBs in human milk from the Faroe Islands
- 2005
-
Ingår i: Environmental Health. - 1476-069X. ; 4:12
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundPersistent organic pollutants (POPs) in wildlife and humans remain a cause of global concern, both in regard to traditional POPs, such as the polychlorinated biphenyls (PCBs), and emerging POPs, such as the polybrominated diphenyl ethers (PBDEs). To determine the time related concentrations, we analyzed human milk for these substances at three time points between 1987 and 1999. Polychlorobiphenylols (OH-PCBs), the dominating class of PCB metabolites, some of which are known to be strongly retained in human blood, were also included in the assessment.MethodsWe obtained milk from the Faroe Islands, where the population is exposed to POPs from their traditional diet (which may include pilot whale blubber). In addition to three pools, nine individual samples from the last time point were also analyzed. After cleanup, partitioning of neutral and acidic compounds, and separation of chemical classes, the analyses were carried out by gas chromatography and/or gas chromatography/mass spectrometry.ResultsCompared to other European populations, the human milk had high PCB concentrations, with pool concentrations of 2300 ng/g fat 1987, 1600 ng/g fat in 1994, and 1800 ng/g fat in 1999 (based on the sum of eleven major PCB congeners). The nine individual samples showed great variation in PCB concentrations. The OH-PCBs were present in trace amounts only, at levels of approximately 1% of the PCB concentrations. The PBDE concentrations showed a clear increase over time, and their concentrations in human milk from 1999 are among the highest reported so far from Europe, with results of individual samples ranging from 4.7 to 13 ng/g fat.ConclusionAlthough remote from pollution sources, the Faroe Islands show high concentrations of POPs in human milk, particularly PCBs, but also PBDEs. The PBDEs show increasing concentrations over time. The OH-PCB metabolites are poorly transferred to human milk, which likely is related to their acidic character.
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| 30. |
- Fängström, Britta, et al.
(författare)
-
Analys av polybromerade difenyletrar (PBDE) och hexabromcyklododekan (HBCDD) i human mjölk från Stockholm : en tidstrends studie
- 2005
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The objective of the present study was to assess the temporal trends of polybrominated diphenyl ethers (PBDEs), including decaBDE, and hexabromocyclododecane (HBCDD) in mothers milk from the Stockholm area. The pooled samples were covering the time period 1980 to 2004, with emphasis on samples from the last ten years. The temporal trend of PBDEs must be expressed on a congener basis since the development of the individual PBDE congener concentrations differ. BDE-47, -99 and -100 concentrations reached a peak in the mid 1990’s and are now clearly showing decreasing levels. BDE-153 concentrations increased until year 2000 and thereafter the concentrations may level off but it is yet not clear how the concentrations of this PBDE congener will develop over the next few years. It is not possible to quantify decaBDE (BDE-209) in the human milk. This may be due to poor transfer to the milk lipids but most likely it is a result of the short half-life of this compound in human blood. HBCDD concentrations are 2004, approximately four times the concentration in 1980 showing an increasing temporal trend until the early 2000’s. It is too early to judge if the levels are decreasing or leveling off. The HBCDD concentrations are in a range between BDE-47 and BDE-99 and BDE-100.
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| 31. |
- Fängström, Britta, et al.
(författare)
-
Rapport till Naturvårdsverket för projektet "Analys av polybromerade difenyletrar (PBDE) och hexabromcyklododekan (HBCDD) i human mjölk från Stockholm – en tidstrends studie [Dnr 721-2653-05Mm]
- 2005
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The objective of the present study was to assess the temporal trends of polybrominated diphenyl ethers (PBDEs), including decaBDE, and hexabromocyclododecane (HBCDD) in mothers milk from the Stockholm area. The pooled samples were covering the time period 1980 to 2004, with emphasis on samples from the last ten years. The temporal trend of PBDEs must be expressed on a congener basis since the development of the individual PBDE congener concentrations differ. BDE-47, -99 and -100 concentrations reached a peak in the mid 1990’s and are now clearly showing decreasing levels. BDE-153 concentrations increased until year 2000 and thereafter the concentrations may level off but it is yet not clear how the concentrations of this PBDE congener will develop over the next few years. It is not possible to quantify decaBDE (BDE-209) in the human milk. This may be due to poor transfer to the milk lipids but most likely it is a result of the short half-life of this compound in human blood. HBCDD concentrations are 2004, approximately four times the concentration in 1980 showing an increasing temporal trend until the early 2000’s. It is too early to judge if the levels are decreasing or leveling off. The HBCDD concentrations are in a range between BDE-47 and BDE-99 and BDE-100.
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| 32. |
- Gittins, John R., et al.
(författare)
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Identification of a novel nuclear factor-binding site in the Pisum sativum sad gene promoters
- 2002
-
Ingår i: Biochimica et Biophysica Acta, Gene Structure and Expression. - 0167-4781 .- 1879-2634. ; 1574:3, s. 231-244
-
Tidskriftsartikel (refereegranskat)abstract
- DNA fragments containing the 5' promoter regions of the Pisum sativum sadA and sadC genes were amplified from genomic DNA, cloned and sequenced. These sequences contain a number of conserved cis-acting elements, which are potentially involved in stress-induced transcription of the sad genes. To determine whether any of the identified elements are active in binding nuclear factors in vitro, 11 60-bp overlapping (by 30 bp) DNA probe fragments covering the proximal sadC promoter sequence (360 bp) were used in electrophoretic mobility shift assays with competition. Binding activities were compared in nuclear extracts from control, UV-B-stressed and wounded pea leaves. The pattern of DNA binding was almost identical with all three extracts, with one 30-bp region being the predominant site for factor binding. Using overlapping sub-fragments of this region, the majority of the specific binding could be attributed to the novel 11-bp GC-rich sequence GTGGCGCCCAC. An almost identical sequence is conserved in the sadA promoter. This motif has features in common with a number of recognised cis-elements, which suggests a possible binding site for factors which play a role in regulating sad gene transcription.
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| 33. |
- Hadad, Ronza, et al.
(författare)
-
Optimization of infection in murine model with Chlamydia trachomatis for vaccine studies
- 2013
-
Ingår i: Chlamydia Basic Research Society.
-
Konferensbidrag (refereegranskat)abstract
- Background and Significance: Vaccine studies for Chlamydia trachomatis (Ct) have been hampered by the lack of an ideal murine model. Ct is not ideal for infection and subsequent pathology as it is a human pathogen and C. muridarum (Cm) may not be suitable due to vaccine specificity for Ct. There is currently no standardization of chlamydial infections in murine models concerning mouse strain, infecting agent and dose. Objectives: To investigate the Ct infection in mice, using different suppliers of mice, doses and the infective agents of Ct serovars D, E and Cm. Methods: C57BL/6 mice (Taconic; Harlan; in-house breeding mice) were inoculated intravaginally with 103-105 chlamydia elementary bodies (EB). Vaginal samples were collected at 7-8 days intervals and analyzed using MicroTrak II Chlamydia EIA kit. Results: Taconic mice inoculated with Ct D with 105 EB showed the strongest infection with 30% of mice infected at day 21 (d21) as seen in figure 1. The number of infected mice and detected antigen (not shown) decreased rapidly after the first time-point (d8). In figure 2 infective agents were analyzed. Ct E did not infect any mice despite using a tenfold increased dose. Cm infection was detectable in 80% of the mice for up to d21. Conclusions: Ct D infected the mice for a period of 2-3 weeks. There was only a small difference between the suppliers in favor for Harlan mice. Ct D 105 EB was the infectious dose with the highest number of infected mice over time, however the appropriateness of that high bacterial load must be considered. Ct E did not infect these mice and Cm, a mouse pneumonitis strain, infected all mice and had the longest duration of infection. However, for vaccine studies, Cm may not be suitable due to lack of cross reactivity and Ct may still be used however vaginal sampling must be more frequent early on to show significant differences in bacterial shedding between immunized and non-immunized mice.
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| 34. |
- Hadad, Ronza, 1984-, et al.
(författare)
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Protection against genital tract Chlamydia trachomatis infection following intranasal immunization with a novel recombinant MOMP VS2/4 antigen
- 2016
-
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - Hoboken, USA : Wiley-Blackwell. - 0903-4641 .- 1600-0463. ; 124, s. 1078-1086
-
Tidskriftsartikel (refereegranskat)abstract
- The asymptomatic nature of most Chlamydia trachomatis infections and the lack of appropriate effects by current prevention and management call for vaccine development. We evaluated a recombinant subunit vaccine candidate based on the major outer membrane protein variable segments 2 and 4 (MOMP VS2/4). To achieve maximal immunogenicity and ease of production and purification, MOMP VS2/4 was constructed by using highly immunogenic sequences of MOMP only, thereby minimizing the presence of hydrophobic regions, and spacing the immunogenic epitopes with a flexible amino acid sequence. A purification tag was also added. The MOMP VS2/4 was given intranasally, with or without intravaginal boost, with cholera toxin (CT) adjuvant to C57BL/6 mice, which were screened for immunogenicity and protection against a live challenge infection with C. trachomatis serovar D. Bacterial shedding, cell-mediated responses, and antibody responses were monitored. Immunized mice exhibited significantly less bacterial shedding and were better protected against infertility as compared to unimmunized control mice. Immunizations stimulated both systemic and local specific antibody (IgG1, IgG2c, and IgA) responses, and primed T cells that produced interferon-c and interleukins 13 and 17 upon challenge with recall antigen. Thus, MOMP VS2/4, in combination with CT adjuvant, stimulated Th1, Th2, and Th17 effector cells, and generated protective immunity associated with less pathology. We regard MOMP VS2/4 as a promising candidate for further development into a mucosal chlamydial vaccine.
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| 35. |
- Hansson, Charlotta, et al.
(författare)
-
Feeding transgenic plants that express a tolerogenic fusion protein effectively protects against arthritis
- 2016
-
Ingår i: Plant Biotechnology Journal. - : Wiley-Blackwell. - 1467-7644 .- 1467-7652. ; 14:4, s. 1106-1115
-
Tidskriftsartikel (refereegranskat)abstract
- Although much explored, oral tolerance for treatment of autoimmune diseases still awaits the establishment of novel and effective vectors. We investigated if the tolerogenic CTA1(R7K)-COL-DD fusion protein can be expressed in edible plants and in this way induce oral tolerance and protect against arthritis. The fusion protein was recombinantly expressed in Arabidopsis thaliana plants, which were fed to H-2q restricted DBA/1 mice to assess the preventive effect on collagen-induced arthritis (CIA). The treatment resulted in fewer mice exhibiting disease and arthritis scores were significantly reduced. Immune suppression was evident in treated mice and serum biomarkers for inflammation as well as anti-collagen IgG responses were reduced. In spleen draining and lymph nodes, CD4+ T cell responses were reduced. Concomitant with a reduced effector T cell activity with lower IFNg, IL-13 and IL-17A production we observed an increase in IL-10 production to recall antigen stimulation in vitro, suggesting reduced Th1, Th2 and Th17 activity subsequent to upregulated IL-10 and regulatory T cell (Treg) functions. The present study shows that edible plants expressing a tolerogen were effective at stimulating CD4 T cell tolerance and in protecting against CIA disease. Our study conveys optimism as to the potential of using edible plants for oral treatment of rheumatoid arthritis.
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| 36. |
- Hideg, Éva, 1960-, et al.
(författare)
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The effects of UV-B on the biochemistry and metabolism of plants
- 2017
-
Ingår i: UV-B radiation and plant life. - Wallingford, UK : CABI Publishing. - 9781780648590 - 9781780648606 ; , s. 90-110
-
Bokkapitel (refereegranskat)abstract
- This chapter focuses on the effects of UV-B radiation on the biochemistry and metabolism of plants and their underlying mechanisms. Information on the UV-inducible metabolites and protection responses of plants against UV-B radiation are also discussed.
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| 37. |
- Hideg, Éva, et al.
(författare)
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UV-B exposure, ROS, and stress : inseparable companions or loosely linked associates?
- 2013
-
Ingår i: Trends in Plant Science. - : Cell Press. - 1360-1385 .- 1878-4372. ; 18:2, s. 107-115
-
Tidskriftsartikel (refereegranskat)abstract
- Ultraviolet-B (UV-B) radiation has long been perceived as a stressor. However, a conceptual U-turn has taken place, and UV-B damage is now considered rare. We question whether UV-stress and UV-B-induced reactive oxygen species (ROS) are still relevant concepts, and if ROS-mediated signaling contributes to UV-B acclimation. Measurements of antioxidants and of antioxidant genes show that both low and high UV-B doses alter ROS metabolism. Yet, there is no evidence that ROS control gene expression under low UV-B. Instead, expression of antioxidant genes is linked to the UV RESISTANCE LOCUS 8 pathway. We hypothesize that low UVB doses cause ‘eustress’ (good stress) and that stimulispecific signaling pathways pre-dispose plants to a state of low alert that includes activation of antioxidant defenses.
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| 38. |
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| 39. |
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| 40. |
- Kalbin, Georgi, et al.
(författare)
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Effects of UV-B in biological and chemical systems : equipment for wavelength dependence determination
- 2005
-
Ingår i: Journal of Biochemical and Biophysical Methods. - : Elsevier BV. - 0165-022X .- 1872-857X. ; 65:1, s. 1-12
-
Tidskriftsartikel (refereegranskat)abstract
- The thinning of the stratospheric ozone layer has prompted a large number of studies of UV-B-induced effects in biological and chemical systems. The wavelength dependency of such effects is of interest from mechanistic, physiological or economic points of view. Here, we describe an apparatus for determining the wavelength dependency of UV-B effects in biological and chemical systems. The apparatus consists of a high intensity UV radiation source and narrow bandpass filters to produce UV radiation in even intervals (between 280 and 360 nm). The usefulness of the equipment is demonstrated in two different systems: 1) Chalcone synthase (CHS) gene is up-regulated by UV-B radiation. Therefore quantitative analysis of the CHS gene expression was chosen in the present investigation for studies of the wavelength dependency of gene expression regulation in plants. Maximum induction of CHS expression was found at 300 nm with a 12-fold induction compared with the control; 2) The wavelength dependency of formation of dioxin-like photoproducts from the brominated flame retardant decabrominated diphenyl ether (DeBDE) is described. This is an example of UV-B-induced conversion of non-toxic species into a number of products of which some may be toxic in the environment. In the UV interval studied, the highest dioxin-like activity was found in the sample irradiated at 330 nm and therefore this wavelength is most important for the mechanism involved in photoconversion of DeBDE.
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| 41. |
- Kalbin, Georgi, et al.
(författare)
-
Ultraviolet-B-radiation-induced changes in nicotinamide and glutathione metabolism and gene expression in plants
- 1997
-
Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 249:2, s. 465-472
-
Tidskriftsartikel (refereegranskat)abstract
- Pea (Pisum sativum L. cv. Greenfeast) plants were exposed to supplementary ultraviolet-B (UV-B) radiation (biologically effective dose rates normalised to 300 nm UV-B-BE,B-300: 0.18, 0.32 or 1.4 W m(-2)). Leaf nicotinamide, trigonelline, GSH(tot) (total glutathione) and (GSSG (oxidised glutathione) levels remained unchanged after exposure to the lowest dose rates. 1.4 W m(-2) UV-B-BE,B-300 gave rise to 60-fold and 4.5-fold increases in GSSG and GSH(tot), respectively. 3.5-fold and 9.5-fold increases were found in nicotinamide and trigonelline, respectively. cab (Chlorophyll-a/b-binding protein) transcript levels decreased and CHS (chalcone synthase) and PAL (phenylalanine ammonia-lyase) mRNA increased after shorter UV-B exposures (hours) to the higher dose rate of UV-B and after exposure to the intermediate dose rate. CHS and PAL mRNAs also increased after prolonged exposure to the lowest dose rate. cab transcripts completely disappeared. whereas CHS and PAL mRNA levels rose by 60-fold and 17-fold, respectively, after 12 h exposure at the highest dose rate and 12 h of development. Our results indicate that nicotinamide or trigonelline do not function as signalling compounds for CHS and PAL gene expression. Elevated nicotinamide and trigonelline levels occur in response to UV-B, but only at UV-B doses high enough to cause oxidative stress.
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| 42. |
- Kalbin, Georgi, et al.
(författare)
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UV-B-induced DNA damage and expression of defence genes under UV-B stress : tissue-specific molecular marker analysis in leaves
- 2001
-
Ingår i: Plant, Cell and Environment. - : Wiley. - 0140-7791 .- 1365-3040. ; 24:9, s. 983-990
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the regulatory effect of ultraviolet-B (UV-B) radiation on a number of key stress response genes found in the epidermis and mesophyll of Pisum sativum L., Argenteum mutant. This mutant was chosen for the ease with which the entire epidermis can be removed from the mesophyll tissue. An additional goal was to explore the potential modifying effect of pre-acclimation of plants to UV-B radiation prior to exposure by UV-B during treatment. Results showed that mRNA accumulation was similar during acute short-term UV-B exposure for chalcone synthase (Chs) and short-chain alcohol dehydrogenase (SadA) in both epidermis and mesophyll. In contrast, the mRNA levels differed considerably between tissues for phenylalanine ammonia lyase, chalcone isomerase and lipid transfer protein. After 24 h incubation in visible light after cessation of UV-B exposure, the regulation of mRNA levels also differed between Chs and SadA, the former showing no expression in the epidermis and the latter none in the mesophyll. Acclimation to low UV-B levels before acute exposures resulted in delayed induction of Chs and SadA. Measurements of UV-B-induced cyclobutane pyrimidine dimers (CPDs) showed a greater formation in epidermis than in mesophyll. In addition, acclimation at low UV-B levels resulted in significantly higher basal levels of CPDs than in non-acclimated plants in both mesophyll and epidermis and also in increased damage in concomitant acute exposures. The lack of correlation between the number of CPDs and levels of transcripts for defence genes, indicates that DNA damage does not control transcription of these genes.
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| 43. |
- Kalbina, Irina, et al.
(författare)
-
A novel chimeric MOMP antigen expressed in Escherichia coli, Arabidopsis thaliana, and Daucus carota as a potential Chlamydia trachomatis vaccine candidate
- 2011
-
Ingår i: Protein Expression and Purification. - : Elsevier BV. - 1046-5928 .- 1096-0279. ; 80:2, s. 194-202
-
Tidskriftsartikel (refereegranskat)abstract
- The major outer membrane protein (MOMP) of Chlamydia trachomatis is a highly antigenic and hydrophobic transmembrane protein. Our attempts to express the full-length protein in a soluble form in Escherichia coli and in transgenic plants failed. A chimeric gene construct of C trachomatis serovar E MOMP was designed in order to increase solubility of the MOMP protein but with retained antigenicity. The designed construct was successfully expressed in E. coil, in Arabidopsis thaliana, and in Daucus carota. The chimeric MOMP expressed in and purified from E. coil was used as antigen for production of antibodies in rabbits. The anti-chimeric MOMP antibodies recognized the corresponding protein in both E. coli and in transgenic plants, as well as in inactivated C. trachomatis elementary bodies. Transgenic Arabidopsis and carrots were characterized for the number of MOMP chimeric genetic inserts and for protein expression. Stable integration of the transgene and the corresponding protein expression were demonstrated in Arabidopsis plants over at least six generations. Transgenic carrots showed a high level of expression of the chimeric MOMP - up to 3% of TSP.
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| 44. |
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| 45. |
- Kalbina, Irina, 1961-, et al.
(författare)
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Arabidopsis thaliana plants expressing Rift Valley fever virus antigens : Mice exhibit systemic immune responses as the result of oraladministration of the transgenic plants
- 2016
-
Ingår i: Protein Expression and Purification. - San Diego, USA : Elsevier. - 1046-5928 .- 1096-0279. ; 127, s. 61-67
-
Tidskriftsartikel (refereegranskat)abstract
- The zoonotic Rift Valley fever virus affects livestock and humans in Africa and on the Arabian Peninsula.The economic impact of this pathogen due to livestock losses, as well as its relevance to public health,underscores the importance of developing effective and easily distributed vaccines. Vaccines that can bedelivered orally are of particular interest.Here, we report the expression in transformed plants (Arabidopsis thaliana) of Rift Valley fever virusantigens. The antigens used in this study were the N protein and a deletion mutant of the Gn glycoprotein.Transformed lines were analysed for specific mRNA and protein content by RT-PCR and Westernblotting, respectively. Furthermore, the plant-expressed antigens were evaluated for their immunogenicityin mice fed the transgenic plants. After oral intake of fresh transgenic plant material, a proportionof the mice elicited specific IgG antibody responses, as compared to the control animals that were fedwild-type plants and of which none sero-converted.Thus, we show that transgenic plants can be readily used to express and produce Rift Valley Fever virusproteins, and that the plants are immunogenic when given orally to mice. These are promising findingsand provide a basis for further studies on edible plant vaccines against the Rift Valley fever virus.
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| 46. |
- Kalbina, Irina, 1961-, et al.
(författare)
-
Construction, immunogenicity and protective efficacy in mice of a prototype chimeric Chlamydia trachomatis MOMP vaccine candidate antigen
- 2011
-
Konferensbidrag (refereegranskat)abstract
- A chimeric gene construct of Chlamydia trachomatis serovar E major outer membrane protein (MOMP) was designed, and expressed as a candidate vaccine antigen. The construct was based on known T and B cell epitopes located in the variable segment (VS) 2 and 4 loops of MOMP, and successfully expressed and purified in a recombinant Escherichia coli system. BALB/c mice were immunized intranasally with the chimeric MOMP antigen and Cholera toxin (CT) adjuvant, three immunizations with 10 days intervals. A final boost with the identical antigen preparation was given intravaginally. Challenge with live C. trachomatis serovar D was performed 10 days after boost. Antibodies in serum and vaginal washes were determined with the identical chimeric MOMP construct as antigen in ELISAs. All mice in vaccine groups (N=10/group and experiment) developed a strong antigen-specific IgG response in serum, and some also had detectable antigen-specific IgG in vaginal washes. An IgA response, albeit weaker, was detected in some of the mice both in serum and in vaginal washes.After challenge with C. trachomatis, 80 and 100% of the mice became infected in two experiments, respectively. However, the vaccinated groups cleared the infection significantly faster than control groups (all vaccinated mice healthy day 24 [90% day 16], compared to day 40 for controls).Thus, the new chimeric MOMP antigen construct gave rise to a significant immune response in mice (s-IgG). It also conferred substantial protection to infection caused by genital C. trachomatis infection of a different subtype.
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| 47. |
- Kalbina, Irina, 1961-, et al.
(författare)
-
Expression of chimeric Chlamydia trachomatis MOMP protein antigen in Arabidopsis thaliana and Daucus carota
- 2011
-
Ingår i: Molecular farming. - Bryssel : COST. ; , s. 38-38
-
Konferensbidrag (refereegranskat)abstract
- Urogenital chlamydial infection, caused by Chlamydia trachomatis, is the main sexually transmitted infection in Sweden. Despite active programmes for detection and case finding, nearly 37 000 cases were reported in 2010. Serovar E strains are considered to cause approximately 40-50% of these cases. A vaccine would be highly valuable in order to control the epidemic.The major outer membrane protein (MOMP) of Chlamydia trachomatis is a highly antigenic and hydrophobic transmembrane protein. Our attempts to express the full-length protein in a soluble form in transgenic plants failed. A chimeric gene construct of Chlamydia trachomatis serovar E MOMP was designed in order to increase solubility of the MOMP protein but with retained antigenicity. The construct was based on known T and B cell epitopes located in the variable segment (VS) 2 and 4 loops of MOMP.The designed construct was successfully expressed in Arabidopsis thaliana, and in Daucus carota. A chimeric MOMP expressed in and purified from E. coli was used as antigen for production of antibodies in rabbits. The anti-chimeric MOMP antibodies recognized the corresponding protein in the transgenic plants, as well as in inactivated C. trachomatis elementary bodies. Transgenic Arabidopsis and carrots were characterized for the number of MOMP chimeric genetic inserts and for protein expression. Stable integration of the transgene and the corresponding protein expression were demonstrated in Arabidopsis plants over at least six generations. Transgenic carrots showed a high level of expression of the chimeric MOMP– up to 3% of TSP.
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| 48. |
- Kalbina, Irina, et al.
(författare)
-
Expression of Helicobacter pylori TonB Protein in Transgenic Arabidopsis thaliana : toward production of vaccine antigens in plants
- 2010
-
Ingår i: Helicobacter. - : John Wiley & Sons. - 1083-4389 .- 1523-5378. ; 15:5, s. 430-437
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Tidskriftsartikel (refereegranskat)abstract
- Background: The aim of this study was to produce a recombinant version of the highly antigenic Helicobacter pylori TonB (iron-dependent siderophore transporter protein HP1341) in transgenic plants as a candidate oral vaccine antigen. Materials and Methods: Using Agrobacterium-mediated gene transfer, we introduced three different constructs of the tonB gene into the genome of the model plant Arabidopsis thaliana. We investigated transgene insertion by PCR, produced TonB antibodies for analysis of the production of the recombinant protein in plants, verified the identity of the protein produced by mass spectrometry analysis, and analyzed the number of genetic inserts in the plants by Southern blotting. Results: Three different constructs of the expression cassette (full-length tonB, tonB truncated in the 5' end removing the codons for a transmembrane helix, and the latter construct with codons for the endoplasmic reticulum SEKDEL retention signal added to the 3' end) were used to find the most effective way to express the TonB antigen. Production of TonB protein was detected in plants transformed with each of the constructs, confirmed by both Western blotting and mass spectrometry analysis. No considerable differences in protein expression from the three different constructs were observed. The protein concentration in the plants was at least 0.05% of the total soluble proteins. Conclusions: The Helicobacter pylori TonB protein can be produced in Arabidopsis thaliana plants in a form that is recognizable by rabbit anti-TonB antiserum. These TonB-expressing plants are highly suitable for animal studies of oral adminstration as a route for immunization against Helicobacter infections.
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| 49. |
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| 50. |
- Kalbina, Irina, et al.
(författare)
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Supplementary ultraviolet-B irradiation reveals differences in stress responses between Arabidopsis thaliana ecotypes
- 2006
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Ingår i: Plant, Cell and Environment. - : Wiley. - 0140-7791 .- 1365-3040. ; 29:5, s. 754-763
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Tidskriftsartikel (refereegranskat)abstract
- Irradiation of Arabidopsis thaliana ecotypes C24, Wassilewskija (Ws) and Columbia-0 (Col-0) with supplementary ultraviolet-A+B (UV-A+B) radiation revealed ecotype-specific differences in expression of the gene for the pathogenesis-related protein PR-5. C24 showed an increased expression level of PR-5 (5- and 20-fold higher compared with Col-0 and Ws, respectively). Expression of other molecular markers such as CHS (encoding chalcone synthase), MEB5.2 [encoding a gene strongly up-regulated by ultraviolet-B (UV-B)] and PYROA [encoding a pyridoxine (Vitamin B6) biosynthesis enzyme] only showed slight differences between ecotypes. Oxidative stress during UVA+B exposure was monitored by staining for H2O2. This analysis also revealed important ecotype-specific differences. 'H2O2 hot spots' were found in C24, whereas an even distribution of H2O2 was found in Ws and Col-0. Necrotic lesions also appeared on C24 leaves after prolonged UV-B exposure. There was a reverse correlation between the H2O2 steady-state concentration and the PR-5 gene expression; Ws showed the highest level of H2O2 accumulation but the lowest expression level of the PR-5 gene. Furthermore, application of paraquat on the rosettes led to similar PR-5 expression and H2O2 accumulation patterns as were found after UV-A+B irradiation. The observed ecotypic differences were also reflected in a statistically significant UV-B-dependent decrease in biomass, rosette size and leaf area for Ws, but not for C24 and Col-0. Our results show that a significant ecotype-specific genetic variability in general UV-B responses in Arabidopsis exists. Moreover, the signal transduction or gene regulation pathway for PR-5 differs from the other molecular markers used in this study.
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