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- 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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| 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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| 5. |
- Ayala, Marcelo, et al.
(författare)
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p53 expression and apoptosis in the lens after ultraviolet radiation exposure
- 2007
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Ingår i: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 48:9, s. 4187-4191
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To localize p53 protein and active caspase-3 in the albino rat lens and to compare p53 mRNA and active caspase-3 expression in ultraviolet radiation (UVR) 300 nm exposed lenses and their contralateral nonexposed controls. METHODS: Ten Sprague-Dawley albino rats were unilaterally exposed to 8 kJ/m(2) UVR, and the contralateral eyes were left nonexposed. In total, four exposed lenses and their respective contralateral nonexposed lenses were analyzed by immunohistochemistry to localize p53 and active caspase-3. In addition, six exposed and contralateral nonexposed lenses were analyzed by real-time RT-PCR. Quantified p53 and caspase-3 expression were compared between the in vivo UVR 300 nm exposed lenses and the contralateral nonexposed lenses. RESULTS: All lenses exposed to UVR developed cataract. Immunohistochemistry showed that p53 and active caspase-3 were localized in the lens epithelial cells. Quantified p53 and caspase-3 expression were significantly higher in lenses exposed to UVR than in nonexposed lenses. CONCLUSIONS: p53 and caspase-3 expression increase in lens epithelial cells after UVR exposure. In the lens, apoptosis induced by UVR may be associated with increased p53 expression.
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| 6. |
- Kumawat, Ashok Kumar, 1982-, et al.
(författare)
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Microscopic colitis patients demonstrate a mixed Th17/Tc17 and Th1/Tc1 mucosal cytokine profile
- 2013
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Ingår i: Molecular Immunology. - : Elsevier BV. - 0161-5890 .- 1872-9142. ; 55:3-4, s. 355-364
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Tidskriftsartikel (refereegranskat)abstract
- Background:Microscopic colitis (MC) is a chronic inflammatory bowel disorder of unknown aetiology comprising collagenous colitis (CC) and lymphocytic colitis (LC). Data on the local cytokine profile in MC is limited. This study investigated the T helper (Th) cell and cytotoxic T lymphocyte (CTL) mucosal cytokine profile at messenger and protein levels in MC patients.Methods:Mucosal biopsies from CC (n = 10), LC (n = 5), and CC or LC patients in histopathological remission (CC-HR, n = 4), (LC-HR, n = 6), ulcerative colitis (UC, n = 3) and controls (n = 10) were analysed by real-time PCR and Luminex for expression/production of IL-1 beta, -4, -5, -6, -10, -12, -17, -21, -22, -23, IFN-gamma, TNF-alpha, T-bet and RORC2.Results:Mucosal mRNA but not protein levels of IFN-gamma and IL-12 were significantly up regulated in CC, LC as well as UC patients compared to controls. Transcription of the Th1 transcription factor T-bet was significantly enhanced in CC but not LC patients. mRNA levels for IL-17A, IL-21, IL-22 and IL-6 were significantly up regulated in CC and LC patients compared to controls, albeit less than in UC patients. Significantly enhanced IL-21 protein levels were noted in both CC and LC patients. IL-6 protein and IL-1 beta mRNA levels were increased in CC and UC but not LC patients. Increased mucosal mRNA levels of IFN-gamma, IL-21 and IL-22 were correlated with higher clinical activity, recorded as the number of bowel movements per day, in MC patients.Although at lower magnitude, IL-23A mRNA was upregulated in CC and LC, whereas TNF-alpha protein was increased in CC, LC as well as in UC patients.Neither mRNA nor protein levels of IL-4, IL-5 or IL-10 were significantly changed in any of the colitis groups. LC-HR and especially CC-HR patients had normalized mRNA and protein levels of the above cytokines compared to LC and CC patients. No significant differences were found between LC and CC in cytokine expression/production.Conclusion:LC and CC patients demonstrate a mixed Th17/Tc17 and Th1/Tc1 mucosal cytokine profile.
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| 7. |
- Kumawat, Ashok Kumar, et al.
(författare)
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Microscopic colitis patients have increased frequencies of Ki67+proliferating and CD45RO+ active/memory CD8+ and CD4+8+ mucosal T cells
- 2013
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Ingår i: Journal of Crohn's & Colitis. - Oxford, United Kingdom : Oxford University Press. - 1873-9946 .- 1876-4479. ; 7:9, s. 694-705
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Tidskriftsartikel (refereegranskat)abstract
- Background: Collagenous colitis (CC) and lymphocytic colitis (LC) are chronic inflammatory bowel disorders of unknown etiology. This study investigated phenotypic characteristics of the mucosal lymphocytes in CC and LC.Methods: Lamina propria and intraepithelial lymphocytes (LPLs, IELs) isolated from mucosal biopsies from CC (n = 7), LC (n = 6), as well as LC or CC patients in histopathological remission, (LC-HR) (n = 6) and CC-HR (n = 4) and non-inflamed controls (n = 10) were phenotypically characterized by four-color flow cytometry.Results: The proportions of CD8+ IELs were increased in CC and LC (p < 0.01) compared to controls. Increased proportions of CD45RO+CD8+ IELs and LPLs were observed in LC and even more in CC patients (p < 0.01). Both CC (p < 0.05) and LC patients had elevated proportions of CD4+8+ IELs and LPLs compared to controls. The proportions of CD45RO+ cells were increased in CD4+8+ IELs and LPLs (p < 0.05) in CC and LC patients compared to controls. Both CC (p < 0.05) and LC patients had higher proportions of Ki67+CD8+ IELs and LPLs compared to controls.In contrast, decreased proportions of CD4+ LPLs were observed in CC and LC as well as CD4+ IELs in LC compared to controls. Increased proportions of Ki67+CD4+ IELs and LPLs (p < 0.05) were observed in CC and LC patients. CC-HR but not LC-HR patients demonstrated normalized proportions of both IELs and LPLs compared to CC and LC patients respectively.Conclusion: LC and CC patients have differences in mucosal lymphocyte subsets, with increased proportions of Ki67+ and CD45RO+ CD8+ and CD4+8+ mucosal T cells.
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| 10. |
- Prenkert, Malin, 1967-, et al.
(författare)
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CRIM1 is expressed at higher levels in drug-resistant than in drug-sensitive myeloid leukemia HL60 cells
- 2010
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Ingår i: Anticancer Research. - Athens, Greece : International Institute of Anticancer Research. - 0250-7005 .- 1791-7530. ; 30:10, s. 4157-61
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim of this study was to explore possible differences in the mRNA expression levels of CRIM1, SMAD5, BMP4 and BMP7 in sensitive (S) and multidrug-resistant (R0.5) myeloid leukemia HL60 cells.Materials and Methods: HL60S and HL60R0.5 cells were exposed to daunorubicin (DNR) or cytarabine (Ara-C).Results: Baseline levels of CRIM1 were found to be 15-fold higher in HL60R0.5 than in HL60S. Sixteen hours of exposure to DNR resulted in a 5.6-fold increase in CRIM1 levels in HL60S. Exposure to either DNR or Ara-C resulted in modest increases in CRIM1 levels in HL60R0.5. Similarly, baseline levels of SMAD5 and BMP4 were higher in HL60R0.5 than in HL60S cells. Analysis of the drug SMAD5-resistance marker permeability-glycoprotein (Pgp) revealed that CRIM1 and Pgp exhibit a covariance pattern of expression.Conclusion: This study demonstrated that CRIM1 is expressed at high levels in resistant leukemia cells, indicating that CRIM1 may play a role in drug-resistance.
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