| 1. |
- Acheva, Anna, et al.
(författare)
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Presence of Stromal Cells Enhances Epithelial-to-Mesenchymal Transition (EMT) Induction in Lung Bronchial Epithelium after Protracted Exposure to Oxidative Stress of Gamma Radiation
- 2019
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Ingår i: Oxidative Medicine and Cellular Longevity. - : Hindawi Limited. - 1942-0900 .- 1942-0994. ; 2019
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to investigate the role of a microenvironment in the induction of epithelial-to-mesenchymal transition (EMT) as a sign of early stages of carcinogenesis in human lung epithelial cell lines after protracted low-dose rate gamma-radiation exposures. BEAS-2B and HBEC-3KT lung cell lines were irradiated with low-dose rate gamma-rays (Cs-137, 1.4 or 14 mGy/h) to 0.1 or 1 Gy with or without adding TGF-beta. TGF-beta-treated samples were applied as positive EMT controls and tested in parallel to find out if the radiation has a potentiating effect on the EMT induction. To evaluate the effect of the stromal component, the epithelial cells were irradiated in cocultures with stromal MRC-9 lung fibroblasts. On day 3 post treatment, the EMT markers: alpha-SMA, vimentin, fibronectin, and E-cadherin, were analyzed. The oxidative stress levels were evaluated by 8-oxo-dG analysis in both epithelial and fibroblast cells. The protracted exposure to low Linear Energy Transfer (LET) radiation at the total absorbed dose of 1 Gy was able to induce changes suggestive of EMT. The results show that the presence of the stromal component and its signaling (TGF-beta) in the cocultures enhances the EMT. Radiation had a minor cumulative effect on the TGF-beta-induced EMT with both doses. The oxidative stress levels were higher than the background in both epithelial and stromal cells post chronic irradiation (0.1 and 1 Gy); as for the BEAS-2B cell line, the increase was statistically significant. We suggest that the induction of EMT in bronchial epithelial cells by radiation requires more than single acute exposure and the presence of stromal component might enhance the effect through free radical production and accumulation.
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| 2. |
- Andreassi, Maria Grazia, et al.
(författare)
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A Longitudinal Study of Individual Radiation Responses in Pediatric Patients Treated with Proton and Photon Radiotherapy, and Interventional Cardiology : Rationale and Research Protocol of the HARMONIC Project
- 2023
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 24:9, s. 8416-
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Tidskriftsartikel (refereegranskat)abstract
- The Health Effects of Cardiac Fluoroscopy and Modern Radiotherapy (photon and proton) in Pediatrics (HARMONIC) is a five-year project funded by the European Commission that aimed to improve the understanding of the long-term ionizing radiation (IR) risks for pediatric patients. In this paper, we provide a detailed overview of the rationale, design, and methods for the biological aspect of the project with objectives to provide a mechanistic understanding of the molecular pathways involved in the IR response and to identify potential predictive biomarkers of individual response involved in long-term health risks. Biological samples will be collected at three time points: before the first exposure, at the end of the exposure, and one year after the exposure. The average whole-body dose, the dose to the target organ, and the dose to some important out-of-field organs will be estimated. State-of-the-art analytical methods will be used to assess the levels of a set of known biomarkers and also explore high-resolution approaches of proteomics and miRNA transcriptomes to provide an integrated assessment. By using bioinformatics and systems biology, biological pathways and novel pathways involved in the response to IR exposure will be deciphered.
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| 3. |
- Averbeck, Dietrich, et al.
(författare)
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Establishing mechanisms affecting the individual response to ionizing radiation
- 2020
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Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 96:3, s. 297-323
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Forskningsöversikt (refereegranskat)abstract
- Purpose: Humans are increasingly exposed to ionizing radiation (IR). Both low (<100 mGy) and high doses can cause stochastic effects, including cancer; whereas doses above 100 mGy are needed to promote tissue or cell damage. 10-15% of radiotherapy (RT) patients suffer adverse reactions, described as displaying radiosensitivity (RS). Sensitivity to IR's stochastic effects is termed radiosusceptibility (RSu). To optimize radiation protection we need to understand the range of individual variability and underlying mechanisms. We review the potential mechanisms contributing to RS/RSu focusing on RS following RT, the most tractable RS group.Conclusions: The IR-induced DNA damage response (DDR) has been well characterized. Patients with mutations in the DDR have been identified and display marked RS but they represent only a small percentage of the RT patients with adverse reactions. We review the impacting mechanisms and additional factors influencing RS/RSu. We discuss whether RS/RSu might be genetically determined. As a recommendation, we propose that a prospective study be established to assess RS following RT. The study should detail tumor site and encompass a well-defined grading system. Predictive assays should be independently validated. Detailed analysis of the inflammatory, stress and immune responses, mitochondrial function and life style factors should be included. Existing cohorts should also be optimally exploited.
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| 4. |
- Babini, Gabriele, et al.
(författare)
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A systems radiation biology approach to unravel the role of chronic low-dose-rate gamma-irradiation in inducing premature senescence in endothelial cells
- 2022
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 17:3
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThe aim of this study was to explore the effects of chronic low-dose-rate gamma-radiation at a multi-scale level. The specific objective was to obtain an overall view of the endothelial cell response, by integrating previously published data on different cellular endpoints and highlighting possible different mechanisms underpinning radiation-induced senescence.Materials and methodsDifferent datasets were collected regarding experiments on human umbilical vein endothelial cells (HUVECs) which were chronically exposed to low dose rates (0, 1.4, 2.1 and 4.1 mGy/h) of gamma-rays until cell replication was arrested. Such exposed cells were analyzed for different complementary endpoints at distinct time points (up to several weeks), investigating cellular functions such as proliferation, senescence and angiogenic properties, as well as using transcriptomics and proteomics profiling. A mathematical model was proposed to describe proliferation and senescence.ResultsSimultaneous ceasing of cell proliferation and senescence onset as a function of time were well reproduced by the logistic growth curve, conveying shared equilibria between the two endpoints. The combination of all the different endpoints investigated highlighted a dose-dependence for prematurely induced senescence. However, the underpinning molecular mechanisms appeared to be dissimilar for the different dose rates, thus suggesting a more complex scenario.ConclusionsThis study was conducted integrating different datasets, focusing on their temporal dynamics, and using a systems biology approach. Results of our analysis highlight that different dose rates have different effects in inducing premature senescence, and that the total cumulative absorbed dose also plays an important role in accelerating endothelial cell senescence.
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| 5. |
- Barregård, Lars, 1948, et al.
(författare)
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Human and Methodological Sources of Variability in the Measurement of Urinary 8-Oxo-7,8-dihydro-2 '-deoxyguanosine
- 2013
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Ingår i: Antioxidants and Redox Signaling. - : Mary Ann Liebert Inc. - 1523-0864 .- 1557-7716. ; 18:18, s. 2377-2391
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) is a widely used biomarker of oxidative stress. However, variability between chromatographic and ELISA methods hampers interpretation of data, and this variability may increase should urine composition differ between individuals, leading to assay interference. Furthermore, optimal urine sampling conditions are not well defined. We performed inter-laboratory comparisons of 8-oxodG measurement between mass spectrometric-, electrochemical- and ELISA-based methods, using common within-technique calibrants to analyze 8-oxodG-spiked phosphate-buffered saline and urine samples. We also investigated human subject- and sample collection-related variables, as potential sources of variability. Results: Chromatographic assays showed high agreement across urines from different subjects, whereas ELISAs showed far more inter-laboratory variation and generally overestimated levels, compared to the chromatographic assays. Excretion rates in timed 'spot' samples showed strong correlations with 24 h excretion (the 'gold' standard) of urinary 8-oxodG (r(p) 0.67-0.90), although the associations were weaker for 8-oxodG adjusted for creatinine or specific gravity (SG). The within-individual excretion of 8-oxodG varied only moderately between days (CV 17% for 24 h excretion and 20% for first void, creatinine-corrected samples). Innovation: This is the first comprehensive study of both human and methodological factors influencing 8-oxodG measurement, providing key information for future studies with this important biomarker. Conclusion: ELISA variability is greater than chromatographic assay variability, and cannot determine absolute levels of 8-oxodG. Use of standardized calibrants greatly improves intra-technique agreement and, for the chromatographic assays, importantly allows integration of results for pooled analyses. If 24 h samples are not feasible, creatinine- or SG-adjusted first morning samples are recommended.
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| 6. |
- Beltran-Pardo, Eliana A., et al.
(författare)
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Sequence analysis of the DNA-repair gene rad51 in the tardigrades Milnesium cf. tardigradum, Hypsibius dujardini and Macrobiotus cf. harmsworthi
- 2013
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Ingår i: Journal of limnology. - : PAGEPress Publications. - 1129-5767 .- 1723-8633. ; 72, s. 80-91
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Tidskriftsartikel (refereegranskat)abstract
- Tardigrades are known for being resistant to extreme conditions, including tolerance to ionising and UV radiation in both the hydrated and the dehydrated state. It is known that these factors may cause damage to DNA. It has recently been shown that single and double DNA strand breaks occur when tardigrades are maintained for a long time in the anhydrobiotic state. This may suggest that perhaps tardigrades rely on efficient DNA repair mechanisms. Among all proteins that comprise the DNA repair system, recombinases such as RecA or Rad51 have a very important function: DNA exchange activity. This enzyme is used in the homologous recombination and allows repair of the damaged strand using homologous non-damaged strands as a template. In this study, Rad51 induction was evaluated by western blot in Milnesium cf. tardigradum, after exposure to gamma radiation. The Rad51 protein was highly induced by radiation, when compared to the control. The rad51 genes were searched in three tardigrades: Milnesium cf. tardigradum, Hypsibius dujardini and Macrobiotus cf. harmsworthi. The gene sequences were obtained by preparing and sequencing transcriptome libraries for H. dujardini and M. cf. harmsworthi and designing rad51 degenerate primers specific for M. cf. tardigradum. Comparison of Rad51 putative proteins from tardigrades with other organisms showed that they are highly similar to the corresponding sequence from the nematode Trichinella spiralis. A structure-based sequence alignment from tardigrades and other organisms revealed that putative Rad51 predicted proteins from tardigrades contain the expected motifs for these important recombinases. In a cladogram tree based on this alignment, tardigrades tend to cluster together suggesting that they have selective differences in these genes that make them diverge between species. Predicted Rad51 structures from tardigrades were also compared with crystalline structure of Rad51 in Saccharomyces cerevisiae. These results reveal that S. cerevisiae Rad51 structure is very similar to that of the three analysed tardigrades. On the other hand the predicted structure of Rad51 from M. cf. harmsworthi and H. dujardini are closer related to each other, than each of them to that of M. cf. tardigradum.
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| 7. |
- Beltrán-Pardo, Eliana, et al.
(författare)
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Effects of ionizing radiation on embryos of the tardigrade Milnesium cf. tardigradum at different stages of development
- 2013
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Ingår i: PLOS ONE. - 1932-6203. ; 8:9, s. e72098-
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Tidskriftsartikel (refereegranskat)abstract
- Tardigrades represent one of the most desiccation and radiation tolerant animals on Earth, and several studies havedocumented their tolerance in the adult stage. Studies on tolerance during embryological stages are rare, but differentialeffects of desiccation and freezing on different developmental stages have been reported, as well as dose-dependent effectof gamma irradiation on tardigrade embryos. Here, we report a study evaluating the tolerance of eggs from theeutardigrade Milnesium cf. tardigradum to three doses of gamma radiation (50, 200 and 500 Gy) at the early, middle, andlate stage of development. We found that embryos of the middle and late developmental stages were tolerant to all doses,while eggs in the early developmental stage were tolerant only to a dose of 50 Gy, and showed a declining survival withhigher dose. We also observed a delay in development of irradiated eggs, suggesting that periods of DNA repair might havetaken place after irradiation induced damage. The delay was independent of dose for eggs irradiated in the middle and latestage, possibly indicating a fixed developmental schedule for repair after induced damage. These results show that thetolerance to radiation in tardigrade eggs changes in the course of their development. The mechanisms behind this patternare unknown, but may relate to changes in mitotic activities over the embryogenesis and/or to activation of responsemechanisms to damaged DNA in the course of development.
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| 8. |
- Beltran-Pardo, Eliana, et al.
(författare)
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Effects of ionizing radiation on embryos of the tardigrade Milnesium cf. tardigradum at different stages of development
- 2013
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Ingår i: PLoS ONE. - : Public Library of Science. - 1932-6203. ; 8:9
-
Tidskriftsartikel (refereegranskat)abstract
- Tardigrades represent one of the most desiccation and radiation tolerant animals on Earth, and several studies havedocumented their tolerance in the adult stage. Studies on tolerance during embryological stages are rare, but differentialeffects of desiccation and freezing on different developmental stages have been reported, as well as dose-dependent effectof gamma irradiation on tardigrade embryos. Here, we report a study evaluating the tolerance of eggs from theeutardigrade Milnesium cf. tardigradum to three doses of gamma radiation (50, 200 and 500 Gy) at the early, middle, andlate stage of development. We found that embryos of the middle and late developmental stages were tolerant to all doses,while eggs in the early developmental stage were tolerant only to a dose of 50 Gy, and showed a declining survival withhigher dose. We also observed a delay in development of irradiated eggs, suggesting that periods of DNA repair might havetaken place after irradiation induced damage. The delay was independent of dose for eggs irradiated in the middle and latestage, possibly indicating a fixed developmental schedule for repair after induced damage. These results show that thetolerance to radiation in tardigrade eggs changes in the course of their development. The mechanisms behind this patternare unknown, but may relate to changes in mitotic activities over the embryogenesis and/or to activation of responsemechanisms to damaged DNA in the course of development.
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| 9. |
- Beltran-Pardo, Eliana, et al.
(författare)
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Sequence analysis of the DNA-repair gene rad51 in the tardigrades Milnesium cf. tardigradum, Hypsibius dujardini and Macrobiotus cf. harmsworthi
- 2013
-
Ingår i: Journal of limnology. - 1129-5767 .- 1723-8633. ; 72:s1, s. 80-91
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Tidskriftsartikel (refereegranskat)abstract
- Tardigrades are known for being resistant to extreme conditions, including tolerance to ionising and UV radiation in both the hydratedand the dehydrated state. It is known that these factors may cause damage to DNA. It has recently been shown that single and double DNAstrand breaks occur when tardigrades are maintained for a long time in the anhydrobiotic state. This may suggest that perhaps tardigrades rely on efficient DNA repair mechanisms. Among all proteins that comprise the DNA repair system, recombinases such as RecA or Rad51 have a very important function: DNA exchange activity. This enzyme is used in the homologous recombination and allows repair of thedamaged strand using homologous non-damaged strands as a template. In this study, Rad51 induction was evaluated by western blot in Milnesium cf. tardigradum, after exposure to gamma radiation. The Rad51 protein was highly induced by radiation, when compared to the control. The rad51 genes were searched in three tardigrades: Milnesium cf. tardigradum, Hypsibius dujardini and Macrobiotus cf. harmsworthi. The gene sequences were obtained by preparing and sequencing transcriptome libraries for H. dujardini and M. cf. harmsworthi and designing rad51 degenerate primers specific for M. cf. tardigradum. Comparison of Rad51 putative proteins from tardigrades with other organisms showed that they are highly similar to the corresponding sequence from the nematode Trichinella spiralis. A structure-based sequence alignment from tardigrades and other organisms revealed that putative Rad51 predicted proteins from tardigrades contain the expected motifs for these important recombinases. In a cladogram tree based on this alignment, tardigrades tend to cluster together suggesting that they have selective differences in these genes that make them diverge between species. Predicted Rad51 structures from tardigrades were also compared with crystalline structure of Rad51 in Saccharomyces cerevisiae. These results reveal that S. cerevisiae Rad51 structure is very similar to that of the three analysed tardigrades. On the other hand the predicted structure of Rad51 from M. cf. harmsworthi and H. dujardini are closer related to each other, than each of them to that of M. cf. tardigradum.
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| 10. |
- Beltran-Pardo, Eliana, et al.
(författare)
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Tolerance to Gamma Radiation in the Tardigrade Hypsibius dujardini from Embryo to Adult Correlate Inversely with Cellular Proliferation
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Tardigrades are highly tolerant to desiccation and ionizing radiation but the mechanisms of this tolerance are not well understood. In this paper, we report studies on dose responses of adults and eggs of the tardigrade Hypsibius dujardini exposed to gamma radiation. In adults the LD50/48h for survival was estimated at similar to 4200 Gy, and doses higher than 100 Gy reduced both fertility and hatchability of laid eggs drastically. We also evaluated the effect of radiation (doses 50 Gy, 200 Gy, 500 Gy) on eggs in the early and late embryonic stage of development, and observed a reduced hatchability in the early stage, while no effect was found in the late stage of development. Survival of juveniles from irradiated eggs was highly affected by a 500 Gy dose, both in the early and the late stage. Juveniles hatched from eggs irradiated at 50 Gy and 200 Gy developed into adults and produced offspring, but their fertility was reduced compared to the controls. Finally we measured the effect of low temperature during irradiation at 4000 Gy and 4500 Gy on survival in adult tardigrades, and observed a slight delay in the expressed mortality when tardigrades were irradiated on ice. Since H. dujardini is a freshwater tardigrade with lower tolerance to desiccation compared to limno-terrestrial tardigrades, the high radiation tolerance in adults, similar to limno-terrestrial tardigrades, is unexpected and seems to challenge the idea that desiccation and radiation tolerance rely on the same molecular mechanisms. We suggest that the higher radiation tolerance in adults and late stage embryos of H. dujardini (and in other studied tardigrades) compared to early stage embryos may partly be due to limited mitotic activity, since tardigrades have a low degree of somatic cell division (eutely), and dividing cells are known to be more sensitive to radiation.
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