| 1. |
- Andersson, Cecilia, et al.
(författare)
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Mice Lacking 12/15-Lipoxygenase have Attenuated Airway Allergic Inflammation and Remodeling.
- 2008
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Ingår i: American Journal of Respiratory Cell and Molecular Biology. - 1535-4989. ; 39:6, s. 648-656
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Tidskriftsartikel (refereegranskat)abstract
- Arachidonate 15-lipoxygenase (LO)-1 has been implicated in allergic inflammation and asthma. The overall effect of 15-LO in allergic inflammation in vivo is, however, unclear. This study investigates systemic allergen sensitization and local allergic airway inflammation and remodeling in mice lacking the murine 12/15-LO, the ortholog to human 15-LO-1. Upon systemic sensitization with intraperitoneal ovalbumin, 12/15 LO(-/-) mice produced elevated levels of allergen-specific IgE compared to wild type (Wt) controls. However, when challenged with repeated aerosolized allergen sensitized 12/15 LO(-/-) mice had an impaired development of airway allergic inflammation compared to Wt controls, as indicated by reduced BAL fluid leukocytes (eosinophils, lymphocytes macrophages) and Th2 cytokines (IL-4, IL-5, IL-13) as well as tissue eosinophils. Allergen-induced airway epithelial proliferation was also significantly attenuated in 12/15 LO(-/-) mice whereas goblet cell hyperplasia was unaffected. However, 12/15 LO(-/-) mice had significantly reduced luminal mucus secretions compared to Wt controls. The repeated allergen challenges resulted in a dramatic increase of alpha-smooth muscle-actin positive alveolar cells in the peripheral airways, a phenomenon that was significantly less developed in 12/15 LO(-/-) mice. In conclusion, our data suggest that 12/15 LO(-/-) mice, although having a fully developed systemic sensitization, did not establish a fully developed allergic airway inflammation and associated manifestations of central and peripheral airway remodeling. These data suggest that 12/15-LO derived metabolites play an important pathophysiological role in allergen-induced inflammation and remodeling. Hence, pharmacologic targeting of the human 15-LO-1 may represent an attractive therapeutic strategy to control inflammation and remodeling in asthma.
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| 2. |
- Claesson, Kristina, 1965
(författare)
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Radiobiological effects of alpha-particles from Astatine-211: From DNA damage to cell death
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- ABSTRACT In recent years, the use of high linear energy transfer (LET) radiation for radiotherapeutic applications has gained increased interest. Astatine-211 (211At) is an -particle emitting radionuclide, promising for targeted radioimmunotherapy of isolated tumor cells and microscopic clusters. To improve development of safe radiotherapy using 211At it is important to increase our knowledge of the radiobiological effects in cells. During radiotherapy, both tumors and adjacent normal tissue will be irradiated and therefore, it is of importance to understand differences in the radioresponse between proliferating and resting cells. The aim of this thesis was to investigate effects in fibroblasts with different proliferation status after irradiation with -particles from 211At or X-rays, from inflicted DNA damage, to cellular responses and biological consequences. Throughout this work, irradiation was performed with -particles from 211A or X-rays. The induction and repair of double-strand breaks (DSBs) in human normal fibroblasts were investigated using pulsed-field gel electrophoresis and fragment analysis. The relative biological effectiveness (RBE) of 211At for DSB induction varied between 1.4 and 3.1. A small increase of DSBs was observed in cycling cells compared to stationary cells. The repair kinetics was slower after 211At and more residual damage was found after 24 h. Comparison between cells with different proliferation status showed that the repair was inefficient in cycling cells with more residual damage, regardless of radiation quality. Activation of cell cycle arrests was investigated using immunofluorescent labeling of the checkpoint kinase Chk2 and by measuring cell cycle distributions with flow cytometry analysis. After -particle irradiation, the average number of Chk2-foci was larger and the cells had a more affected cell cycle progression for several weeks compared with X-irradiated cells, indicating a more powerful arrest after 211At. Flow cytometry showed that cycling cells were arrested in G2/M while stationary cells underwent a delayed entry into S phase after release of contact inhibition. Radiation-induced chromosomal damage was studied by investigating the formation of micronuclei after first mitosis post-irradiation. Alpha-particles induced 2.7 and 4.1 times more micronuclei in cycling and stationary cells, respectively, compared with Xrays. Induction of DSBs and cell survival after irradiation were also investigated in synchronized Chinese hamster fibroblasts. The cells were synchronized with mimosine in G1, early, mid and late S phase and in mitosis and cell survival was determined using the clonogenic assay. The radioresponse between cell cycle phases varied after both 211At and X-rays, resulting in variations of RBE for 211At between 1.8 and 3.9 for DSB induction and between 3.1 and 7.9 for 37% survival. The lowest RBE was observed in mitotic cells for both DSB induction and clonogenic survival. In summary, for all endpoints studied -particles from 211At were more detrimental compared with X-rays. Further, the radioresponse was dependent upon the proliferation status of the cells at the time of irradiation, after both low- and high-LET radiation, resulting in variations of the relative biological effects.
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| 3. |
- Claesson, Kristina, 1965, et al.
(författare)
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RBE of α-particles from 211At for complex DNA damage and cell survival in relation to cell cycle positio.
- 2011
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Ingår i: International journal of radiation biology. - : Informa UK Limited. - 1362-3095 .- 0955-3002.
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Tidskriftsartikel (refereegranskat)abstract
- Purpose:To investigate cell cycle effects and relative biological effectiveness (RBE) of α-particles from the clinically relevant radionuclide Astatine-211 ((211)At), using X-rays as reference radiation. Double-strand breaks (DSB), non-DSB clusters containing oxidised purines and clonogenic survival were investigated. Materials and methods:Asynchronous V79-379A fibroblasts or cells synchronised with mimosine in G1, early, mid and late S phase or in mitosis were irradiated with X-rays (100 kV(p)) or (211)At (mean linear energy transfer (LET) 110 keV/μm). Induction of DSB and clusters was determined using pulsed-field gel electrophoresis with fragment analysis. Cell survival was obtained with the clonogenic assay. Results:In asynchronous cells RBE for DSB- and cluster-induction was 3.5 and 0.59, respectively. RBE for 37% cell survival was 8.6. In different cell cycle phases RBE varied from 1.8-3.9 for DSB and 3.1-7.9 for 37% survival (survival at 2 Gy was 6.9-38 times lower after α-irradiation). (211)At induced 6 times more DSB and X-rays induced 11 times more DSB in mitotic cells with highly compacted chromatin relative G1. Conclusions:The radio-response is cell cycle dependent and differs between proliferating and non-cycling cells for both low- and high-LET radiation, resulting in a variation in RBE of α-particles between 1.8 and 8.6.
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| 4. |
- Claesson, Kristina, 1965, et al.
(författare)
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Relative biological effectiveness of the alpha-particle emitter (211)At for double-strand break induction in human fibroblasts.
- 2007
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Ingår i: Radiation research. - 0033-7587 .- 1938-5404. ; 167:3, s. 312-8
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to quantify and to determine the distribution of DNA double-strand breaks (DSBs) in human cells irradiated in vitro and to evaluate the relative biological effectiveness (RBE) of the alpha-particle emitter (211)At for DSB induction. The influence of the irradiation temperature on the induction of DSBs was also investigated. Human fibroblasts were irradiated as intact cells with alpha particles from (211)At, (60)Co gamma rays and X rays. The numbers and distributions of DSBs were determined by pulsed-field gel electrophoresis with fragment analysis for separation of DNA fragments in sizes 10 kbp-5.7 Mbp. A non-random distribution was found for DSB induction after irradiation with alpha particles from (211)At, while irradiation with low-LET radiation led to more random distributions. The RBEs for DSB induction were 2.1 and 3.1 for (60)Co gamma rays and X rays as the reference radiation, respectively. In the experiments studying temperature effects, nuclear monolayers were irradiated with (211)At alpha particles or (60)Co gamma rays at 2 degrees C or 37 degrees C and intact cells were irradiated with (211)At alpha particles at the same temperatures. The dose-modifying factor (DMF(temp)) for irradiation of nuclear monolayers at 37 degrees C compared with 2 degrees C was 1.7 for (211)At alpha particles and 1.6 for (60)Co gamma rays. No temperature effect was observed for intact cells irradiated with (211)At. In conclusion, irradiation with alpha particles from (211)At induced two to three times more DSB than gamma rays and X rays.
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| 5. |
- Claesson, Lisbeth, 1955, et al.
(författare)
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Comparison of visual acuity charts identifying visual impairment among older people outside the eye clinic
- 2013
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Ingår i: Disability and Rehabilitation. - : Informa UK Limited. - 0963-8288 .- 1464-5165. ; 35:16, s. 1394-1400
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Evaluate the construct validity and describe sensitivity, specificity and predictive value of two short charts of visual acuity (VA) and examine whether these can identify and detect signs of visual impairment among older people. Method: The study included 43 persons, >65 years, with age related eye disease, living in their own homes. An ophthalmologist assessed the individuals' VA at an eye clinic with the 5 m KM chart. A research assistant assessed individuals' VA by the 1 m KM chart and the Visual Acuity Screening Test in their home environment. Results: All persons with a VA level of <0.5 were correctly identified by both instruments. The instruments have good positive and negative predictive values for the 1 m KM chart (73% and 100%) and for the Visual Acuity Screening Test (69% and 100%). The construct validity between the instruments was good, but the assessment at the eye clinic assessed the participants as having higher VA level. Conclusions: Both instruments have good construct validity, considering they were carried out in poorer lighting conditions and a good predictive value for screening out VA levels <0.5. The 1 m KM chart showed the best agreement with the 5 m KM chart.
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| 6. |
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| 7. |
- Cross, Michael J, et al.
(författare)
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The Shb Adaptor Protein Binds to Tyrosine 766 in the FGFR-1 and Regulatesthe Ras/MEK/MAPK Pathway via FRS2 Phosphorylation in Endothelial Cells
- 2002
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Ingår i: Molecular Biology of the Cell. - 1059-1524 .- 1939-4586. ; 13:8, s. 2881-2893
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Tidskriftsartikel (refereegranskat)abstract
- Stimulation of fibroblast growth factor receptor-1 (FGFR-1) is known to result in phosphorylation of tyrosine 766 and the recruitment and subsequent activation of phospholipase C-γ (PLC-γ). To assess the role of tyrosine 766 in endothelial cell function, we generated endothelial cells expressing a chimeric receptor, composed of the extracellular domain of the PDGF receptor-α and the intracellular domain of FGFR-1. Mutation of tyrosine 766 to phenylalanine prevented PLC-γ activation and resulted in a reduced phosphorylation of FRS2 and reduced activation of the Ras/MEK/MAPK pathway relative to the wild-type chimeric receptor. However, FGFR-1–mediated MAPK activation was not dependent on PKC activation or intracellular calcium, both downstream mediators of PLC-γ activation. We report that the adaptor protein Shb is also able to bind tyrosine 766 in the FGFR-1, via its SH2 domain, resulting in its subsequent phosphorylation. Overexpression of an SH2 domain mutant Shb caused a dramatic reduction in FGFR-1–mediated FRS2 phosphorylation with concomitant perturbment of the Ras/MEK/MAPK pathway. Expression of the chimeric receptor mutant and the Shb SH2 domain mutant resulted in a similar reduction in FGFR-1–mediated mitogenicity. We conclude, that Shb binds to tyrosine 766 in the FGFR-1 and regulates FGF-mediated mitogenicity via FRS2 phosphorylation and the subsequent activation of the Ras/MEK/MAPK pathway.
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| 8. |
- Danielsson, Anna, 1973, et al.
(författare)
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Differential gene expression in human fibroblasts after alpha-particle emitter (211)At compared with (60)Co irradiation.
- 2013
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Ingår i: International journal of radiation biology. - : Informa UK Limited. - 1362-3095 .- 0955-3002. ; 89:4, s. 250-258
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The aim of this study was to identify gene expression profiles distinguishing alpha-particle (211)At and (60)Co irradiation. Materials and methods: Gene expression microarray profiling was performed using total RNA from confluent human fibroblasts 5 hours after exposure to (211)At labeled trastuzumab monoclonal antibody (0.25, 0.5, and 1 Gy) and (60)Co (1, 2, and 3 Gy). Results: We report gene expression profiles that distinguish the effect different radiation qualities and absorbed doses have on cellular functions in human fibroblasts. In addition, we identified commonly expressed transcripts between (211)At and (60)Co irradiation. A greater number of transcripts were modulated by (211)At than (60)Co irradiation. In addition, down-regulation was more prevalent than up-regulation following (211)At irradiation. Several biological processes were enriched for both irradiation qualities such as transcription, cell cycle regulation, and cell cycle arrest, whereas mitosis, spindle assembly checkpoint, and apoptotic chromosome condensation were uniquely enriched for alpha particle irradiation. Conclusions: LET-dependent transcriptional modulations were observed in human fibroblasts 5 hours after irradiation exposure. These findings suggest that in comparison with (60)Co, (211)At has the clearest influence on both tumor protein p53-activated and repressed genes, which impose a greater overall burden to the cell following alpha particle irradiation.
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| 9. |
- Dixelius, Johan, et al.
(författare)
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Endostatin-induced tyrosine kinase signaling through the Shb adaptor protein regulates endothelial cell apoptosis
- 2000
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Ingår i: Blood. - 0006-4971 .- 1528-0020. ; 95:11, s. 3403-3411
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Tidskriftsartikel (refereegranskat)abstract
- Endostatin, which corresponds to the C-terminal fragment of collagen XVIII, is a potent inhibitor of angiogenesis. Fibroblast growth factor-2 (FGF-2)-induced angiogenesis in the chicken chorioallantoic membrane was inhibited by endostatin, but not by an endostatin mutant R158/270A, lacking heparin-binding ability. Endostatin was internalized by endothelial cells, but not by mouse fibroblasts. Treatment of murine brain endothelial (IBE) cells with endostatin reduced the proportion of cells in S phase, whereas growth-arrested IBE cells in collagen gels treated with endostatin displayed enhanced tubular morphogenesis. IBE cells overexpressing Shb, an adaptor protein implicated in angiostatin-induced apoptosis, displayed elevated apoptosis and decreased tubular morphogenesis in collagen gels in response to endostatin when added together with FGF-2. Induction of apoptosis was dependent on the heparin-binding ability of endostatin and the expression of Shb with a functional Src homology 2 (SH2)-domain. Endostatin treatment for 10 minutes or 24 hours induced tyrosine phosphorylation of Shb and formation of multiprotein complexes. An Shb SH2 domain fusion protein precipitated a 125-kd phosphotyrosyl protein in endostatin-treated cells. The 125-kd component either contained intrinsic tyrosine kinase activity or occurred in complex with a tyrosine kinase. In conclusion, our data show that endostatin induces tyrosine kinase activity and enhanced apoptosis in FGF-treated endothelial cells.
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| 10. |
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| 11. |
- Magnander, Karin, 1979, et al.
(författare)
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Clustered DNA damage in irradiated human diploid fibroblasts: influence of chromatin organization.
- 2010
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Ingår i: Radiation research. - 1938-5404. ; 173:3, s. 272-82
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Tidskriftsartikel (refereegranskat)abstract
- Clustered DNA damages are induced by ionizing radiation and are defined as two or more lesions within one or two helical turns. The aim of this study was to investigate the induction and repair of clustered DNA damage in cells with emphasis on the influence of structural differences in the chromatin organization. Human fibroblasts were irradiated with X rays and induced DSBs and clustered damages were quantified using pulsed-field gel electrophoresis combined with postirradiation incubation with the base excision repair endonuclease Fpg, which recognizes oxidized purines and cleaves the strand at sites inducing strand breaks. Hence clustered damages appear in enzyme-treated samples as additional DSBs. The chromatin was modified by different pretreatments that resulted in structures with varying compactness and levels of free radical scavenging capacity. We found that the induction of DSBs and clustered damages increased linearly with dose in all structures and that both types of lesions were allocated randomly within the nucleus. The induction yields increased with decreasing compactness of chromatin, and the chromatin effect was larger for clustered lesions than for DSBs. Clustered damages were processed efficiently with a fast and a slow repair component similar to that for induced DSBs.
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| 12. |
- Partheen, Karolina, 1976, et al.
(författare)
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External validation suggests Integrin beta 3 as prognostic biomarker in serous ovarian adenocarcinomas.
- 2009
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Ingår i: BMC cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The majority of women with ovarian cancer are diagnosed in late stages, and the mortality rate is high. The use of biomarkers as prognostic factors may improve the treatment and clinical outcome of these patients. We performed an external validation of the potential biomarkers CLU, ITGB3, CAPG, and PRAME to determine if the expression levels are relevant to use as prognostic factors. METHODS: We analysed the gene expression of CLU, ITGB3, CAPG, and PRAME in 30 advanced staged serous adenocarcinomas with quantitative real-time polymerase chain reaction (QPCR) and the protein levels were analysed in 98 serous adenocarcinomas with western blot for semiquantitative analysis. Statistical differences in mRNA and protein expressions between tumours from survivors and tumours from deceased patients were evaluated using the Mann-Whitney U test. RESULTS: The gene and protein ITGB3 (Integrin beta 3) were significantly more expressed in tumours from survivors compared to tumours from deceased patients, which is in concordance with our previous results. However, no significant differences were detected for the other three genes or proteins CLU, CAPG, and PRAME. CONCLUSION: The loss of ITGB3 expression in tumours from deceased patients and high expression in tumours from survivors could be used as a biomarker for patients with advanced serous tumours.
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| 13. |
- Partheen, Karolina, 1976, et al.
(författare)
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Four potential biomarkers as prognostic factors in stage III serous ovarian adenocarcinomas
- 2008
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Ingår i: International Journal of Cancer. - : Wiley. - 1097-0215 .- 0020-7136. ; 123:9, s. 2130-2137
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Tidskriftsartikel (refereegranskat)abstract
- The mortality rate for patients with ovarian carcinomas is high and the available prognostic factors are insufficient. The use of biomarkers may contribute to better prediction and survival for these patients. We aimed to study the gene and protein expressions for 7 potential biomarkers, to determine if it is possible to use them as prognostic factors. Genes selected from our previous microarray analysis (2006), CLU, ITGB3, TACC1, MUC5B, CAPG, PRAME and TROAP, were analyzed in 19 of the tumors with quantitative real-time polymerase chain reaction (QPCR). We found that CLU and ITGB3 were more expressed in tumors from survivors and PRAME and CAPG were more expressed in tumors from deceased patients. None of the other 3 genes were significantly differently expressed. The protein expressions of CLU, ITGB3, PRAME and CAPG were analyzed in 43 of the tumors with western blot for semiquantitative analysis. We established that the mRNA and protein expressions correlated and that all 4 proteins were significantly differently expressed. Further, immunohistochemistry (IHC) was used to localize the expression of the proteins in the tumor samples. According to our results, the 4 biomarkers CLU, ITGB3, PRAME and CAPG may be used as prognostic factors for patients with stage III serous ovarian adenocarcinomas. (c) 2008 Wiley-Liss, Inc.
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| 14. |
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