The human body is constantly exposed to ionizing radiation of different qualities. Especially the exposure to high-LET (linear energy transfer) particles increases due to new tumor therapy methods using e.g. carbon ions. Furthermore, upon radiation accidents, a mixture of radiation of different quality is adding up to human radiation exposure. Finally, long-term space missions such as the mission to mars pose great challenges to the dose assessment an astronaut was exposed to. Currently, DSB counting using γH2AX foci is used as an exact dosimetric measure for individuals. Due to the size of the γH2AX IRIF of ~ 0.6 μm, it is only possible to count DSB when they are separated by this distance. For high-LET particle exposure, the distance of the DSB is too small to be separated and the dose will be underestimated. In this study, we developed a method where it is possible to count DSB which are separated by a distance of ~ 140 nm. We counted the number of ionizing radiation-induced pDNA-PKcs (DNA-PKcs phosphorylated at T2609) foci (size = 140 nm ± 20 nm) in human HeLa cells using STED super-resolution microscopy that has an intrinsic resolution of 100 nm. Irradiation was performed at the ion microprobe SNAKE using high-LET 20 MeV lithium (LET = 116 keV/μm) and 27 MeV carbon ions (LET = 500 keV/μm). pDNA-PKcs foci label all DSB as proven by counterstaining with 53BP1 after low-LET γ-irradiation where separation of individual DSB is in most cases larger than the 53BP1 gross size of about 0.6 μm. Lithium ions produce (1.5 ± 0.1) IRIF/μm track length, for carbon ions (2.2 ± 0.2) IRIF/μm are counted. These values are enhanced by a factor of 2-3 compared to conventional foci counting of high-LET tracks. Comparison of the measurements to PARTRAC simulation data proof the consistency of results. We used these data to develop a measure for dosimetry of high-LET or mixed particle radiation exposure directly in the biological sample. We show that proper dosimetry for radiation up to a LET of 240 keV/μm is possible.

• MeSH
• biologické markery MeSH
• dávka záření MeSH
• dvouřetězcové zlomy DNA účinky záření   MeSH
• fluorescenční mikroskopie metody   MeSH
• fosforylace účinky záření   MeSH
• HeLa buňky MeSH
• lidé MeSH
• lineární přenos energie MeSH
• lithium škodlivé účinky   MeSH
• oprava DNA účinky záření   MeSH
• proteinkinasy účinky záření   MeSH
• radiační expozice MeSH
• radiometrie metody   MeSH
• těžké ionty škodlivé účinky   MeSH
• uhlík škodlivé účinky   MeSH
• záření gama škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A standard Fricke dosimeter was used to measure the absorbed dose via the oxidation yields of Fe3+ ions in an aqueous environment induced by soft X rays within the "water window" spectral range. We also exploited the property of a neutral solution containing terephthalic acid as a tool for selective detection of OH radicals. Both dosimetric systems were irradiated using the experimental pulsed laser-plasma soft X-ray source as well as conventional 1.25-MeV gamma rays. Radiation chemical yields of Fe3+ ions and OH radicals were determined to be (5.13 ± 0.94) × 10-1 µmol·J-1 (4.95 ± 0.91 100eV-1) and (2.33 ± 0.35) × 10-2 µmol·J-1 (0.23 ± 0.03 100eV-1), respectively. Measurements were supported by Monte Carlo simulations to estimate the linear energy transfer of the water window radiation. The simulation results are in good agreement with expected linear energy transfer of ions inducing the same Fe3+ ion and OH radical radiation chemical yield.

• MeSH
• hydroxylový radikál chemie   účinky záření   MeSH
• ionty chemie   MeSH
• lidé MeSH
• lineární přenos energie MeSH
• metoda Monte Carlo MeSH
• oxidace-redukce MeSH
• radiometrie * MeSH
• rentgenové záření škodlivé účinky   MeSH
• voda chemie   MeSH
• záření gama škodlivé účinky   MeSH
• železo chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Radiotherapy is an important therapeutic approach against cervical cancer but associated with adverse effects including vaginal fibrosis and dyspareunia. We here assessed the immunological and oxidative responses to cervical irradiation in an animal model for radiation-induced cervicitis. Rats were sedated and either exposed to 20 Gy of ionising radiation given by a linear accelerator or only sedated (controls) and euthanized 1-14 days later. The expressions of toll-like receptors (TLRs) and coupled intracellular pathways in the cervix were assessed with immunohistofluorescence and western blot. Expression of cytokines were analysed with the Bio-Plex Suspension Array System (Bio-Rad). We showed that TLRs 2-9 were expressed in the rat cervix and cervical irradiation induced up-regulation of TLR5, TRIF and NF-κB. In the irradiated cervical epithelium, TLR5 and TRIF were increased in concert with an up-regulation of oxidative stress (8-OHdG) and antioxidant enzymes (SOD-1 and catalase). G-CSF, M-CSF, IL-10, IL- 17A, IL-18 and RANTES expressions in the cervix decreased two weeks after cervical irradiation. In conclusion, the rat uterine cervix expresses the TLRs 2-9. Cervical irradiation induces immunological changes and oxidative stress, which could have importance in the development of adverse effects to radiotherapy.

• MeSH
• adaptorové proteiny vezikulární transportní imunologie   MeSH
• cervix uteri imunologie   patologie   MeSH
• cytokiny imunologie   MeSH
• experimentální radiační poranění imunologie   patologie   MeSH
• krysa rodu rattus MeSH
• NF-kappa B imunologie   MeSH
• oxidační stres imunologie   účinky záření   MeSH
• potkani Sprague-Dawley MeSH
• regulace genové exprese imunologie   účinky záření   MeSH
• toll-like receptory imunologie   MeSH
• zánět děložního hrdla imunologie   patologie   MeSH
• záření gama škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Histone posttranslational modifications regulate diverse nuclear functions, including DNA repair. Here, we use mass spectrometry, western blotting, immunohistochemistry and advanced confocal microscopy in order to show radiation-specific changes in the histone signature. We studied wild-type mouse embryonic stem cells (mESCs) and mESCs with a depletion of histone deacetylase 1 (HDAC1), which plays a role in DNA repair. Irradiation by γ-rays increased the S139 phosphorylation of histone H2AX but reduced the level of the H3K9-R17 peptide, which contains S10 phosphorylation (H3S10ph). On an individual cellular level, H3S10ph was low in highly γH2AX-positive UV laser-induced DNA lesions, and this nuclear distribution pattern was not changed by HDAC1 depletion. Despite this fact, spontaneous γH2AX-positive DNA lesions colocalized with large H3S10ph-positive nuclear bodies that appear in the G2 phase of the cell cycle. Similarly, by FLIM-FRET analysis, we observed an interaction between H3S10ph and γH2AX in the G2 phase. However, this interaction was reduced when cells were exposed to γ-rays. A mutual link between H3S10ph and γH2AX was not observed in the G1 phase of the cell cycle. Together, our data show that despite the fact that H3S10ph is not directly involved in DNA repair, a decrease in H3S10 phosphorylation and weakened interaction between H3S10ph and γH2AX is a result of radiation-induced damage of the genome. In this case, γ-irradiation also decreased the number of cells in the G1 phase, characterized by no interaction between H3S10ph and γH2AX.

• MeSH
• fosforylace účinky záření   MeSH
• G1 fáze účinky záření   MeSH
• G2 fáze účinky záření   MeSH
• HeLa buňky MeSH
• histony genetika   metabolismus   MeSH
• lidé MeSH
• myši MeSH
• záření gama škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

We investigated and evaluated post-irradiation survival in cyclooxygenase-2-deficient (COX-2 KO) mice. Thirty-day survival following exposure of COX-2 KO mice to a lethal dose of 8.5 Gy of gamma-rays was observed to be statistically significantly lower in both males and females, as well as when the sexes were merged, in comparisons with their wild-type counterparts. These findings were related to the previous observations concerning the detrimental influence of the COX-2 genetic disruption on hematopoiesis in sublethally irradiated mice. Deteriorated post-irradiation survival of COX-2 KO mice confirmed the previously anticipated conclusion regarding negative influence of the antiinflammatory action of COX-2 deficiency under the conditions of exposure of the animals to ionizing radiation.

• MeSH
• cyklooxygenasa 2 nedostatek   účinky záření   MeSH
• míra přežití trendy   MeSH
• myši knockoutované MeSH
• myši MeSH
• záření gama škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Several members of the TGF-beta family are known to effectively regulate the fate of hematopoietic progenitor cells in a complex and context-dependent manner. Growth differentiation factor-15 (GDF15) is a divergent member of the TGF-beta family. This stress-induced cytokine has been proposed to possess immunomodulatory functions and its high expression is often associated with progression of a variety of pathological conditions. GDF15 is also induced by chemotherapy and irradiation. Very few fundamental studies have been published regarding the effect of GDF15 in hematopoiesis. In this study, we analyzed the hematological status of untreated and gamma-irradiated mice deficient for GDF15 as a result of genetic knock-out (KO), in order to clarify the regulatory role of GDF15 in hematopoiesis. Significant differences between GDF15 KO mice and their pertinent WT controls were found in the parameters of blood monocyte numbers, blood platelet size, and distribution width, as well as in the values of bone marrow granulocyte/macrophage progenitor cells. Different tendencies of some hematological parameters in the GDF15 KO mice in normal conditions and those under exposure of the mice to ionizing radiation were registered. These findings are discussed in the context of the GDF15 gene function and its lack under conditions of radiation-induced damage.

• MeSH
• buňky kostní dřeně metabolismus   účinky záření   MeSH
• hematopoéza fyziologie   účinky záření   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• růstový diferenciační faktor 15 nedostatek   účinky záření   MeSH
• záření gama škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

We studied epigenetics, distribution pattern, kinetics, and diffusion of proteins recruited to spontaneous and γ-radiation-induced DNA lesions. We showed that PML deficiency leads to an increased number of DNA lesions, which was accompanied by changes in histone signature. In PML wt cells, we observed two mobile fractions of 53BP1 protein with distinct diffusion in spontaneous lesions. These protein fractions were not detected in PML-deficient cells, characterized by slow-diffusion of 53BP1. Single particle tracking analysis revealed limited local motion of 53BP1 foci in PML double null cells and local motion 53BP1 foci was even more reduced after γ-irradiation. However, radiation did not change co-localization between 53BP1 nuclear bodies and interchromatin granule-associated zones (IGAZs), nuclear speckles, or chromocenters. This newly observed interaction pattern imply that 53BP1 protein could be a part of not only DNA repair, but also process mediated via components accumulated in IGAZs, nuclear speckles, or paraspeckles. Together, PML deficiency affected local motion of 53BP1 nuclear bodies and changed composition and a number of irradiation-induced foci. J. Cell. Biochem. 117: 2583-2596, 2016. © 2016 Wiley Periodicals, Inc.

• MeSH
• 53BP1 metabolismus   MeSH
• akutní promyelocytární leukemie metabolismus   patologie   radioterapie   MeSH
• fluorescenční protilátková technika MeSH
• intranukleární inkluzní tělíska metabolismus   patologie   účinky záření   MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• nádorové buňky kultivované MeSH
• oprava DNA fyziologie   účinky záření   MeSH
• poškození DNA fyziologie   účinky záření   MeSH
• vztah dávky záření a odpovědi MeSH
• western blotting MeSH
• záření gama škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The nucleolus is a well-organized site of ribosomal gene transcription. Moreover, many DNA repair pathway proteins, including ATM, ATR kinases, MRE11, PARP1 and Ku70/80, localize to the nucleolus (Moore et al., 2011 ). We analyzed the consequences of DNA damage in nucleoli following ultraviolet A (UVA), C (UVC), or γ-irradiation in order to test whether and how radiation-mediated genome injury affects local motion and morphology of nucleoli. Because exposure to radiation sources can induce changes in the pattern of UBF1-positive nucleolar regions, we visualized nucleoli in living cells by GFP-UBF1 expression for subsequent morphological analyses and local motion studies. UVA radiation, but not 5 Gy of γ-rays, induced apoptosis as analyzed by an advanced computational method. In non-apoptotic cells, we observed that γ-radiation caused nucleolar re-positioning over time and changed several morphological parameters, including the size of the nucleolus and the area of individual UBF1-positive foci. Radiation-induced nucleoli re-arrangement was observed particularly in G2 phase of the cell cycle, indicating repair of ribosomal genes in G2 phase and implying that nucleoli are less stable, thus sensitive to radiation, in G2 phase.

• MeSH
• apoptóza účinky záření   MeSH
• buněčné jadérko účinky záření   MeSH
• buněčné linie MeSH
• buněčný cyklus účinky záření   MeSH
• G2 fáze účinky záření   MeSH
• genetická transkripce MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• poškození DNA účinky záření   MeSH
• transkripční iniciační komplex Pol1 - proteiny genetika   metabolismus   MeSH
• ultrafialové záření MeSH
• výpočetní biologie MeSH
• záření gama škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Clustered DNA damage induced by 10, 20 and 30 MeV protons in pBR322 plasmid DNA was investigated. Besides determination of strand breaks, additional lesions were detected using base excision repair enzymes. The plasmid was irradiated in dry form, where indirect radiation effects were almost fully suppressed, and in water solution containing only minimal residual radical scavenger. Simultaneous irradiation of the plasmid DNA in the dry form and in the solution demonstrated the contribution of the indirect effect as prevalent. The damage composition slightly differed when comparing the results for liquid and dry samples. The obtained data were also subjected to analysis concerning different methodological approaches, particularly the influence of irradiation geometry, models used for calculation of strand break yields and interpretation of the strand breaks detected with the enzymes. It was shown that these parameters strongly affect the results.

• MeSH
• biologické modely MeSH
• dvouřetězcové zlomy DNA MeSH
• elektroforéza v agarovém gelu MeSH
• enzymy opravy DNA metabolismus   MeSH
• lineární přenos energie MeSH
• plazmidy metabolismus   účinky záření   MeSH
• poškození DNA * MeSH
• protony škodlivé účinky   MeSH
• roztoky MeSH
• vztah dávky záření a odpovědi MeSH
• záření gama škodlivé účinky   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Micronuclei are small extranuclear bodies resulting from chromosome fragments or the whole chromosomes secluded from daughter nuclei during mitosis. The number of radiation-induced micronuclei reflects the level of chromosomal damage and relates to an absorbed dose and quality of incident ionizing radiation. The aim of the present study was to determine the micronucleus formation as a specific biological marker for acute radiation-induced DNA damage in normal human fibroblasts exposed to 30-MeV protons and Co-60 gamma radiation. We found a linear increase in binuclear cells containing micronuclei for absorbed doses from 1 to 5 Gy for both radiation modalities. However, the total number of micronuclei in binuclear cells follows a linear-quadratic dose dependence. In case of human exposure to mixed radiation fields or high LET radiation, the proportion of binuclear cells containing micronuclei from all binuclear cells can thus serve as a good biomarker of radiation-induced DNA damage.

• MeSH
• buněčné linie MeSH
• fibroblasty účinky záření   MeSH
• lidé MeSH
• lineární přenos energie MeSH
• mikrojaderné testy MeSH
• mikrojádra chromozomálně defektní účinky záření   MeSH
• poškození DNA MeSH
• protony škodlivé účinky   MeSH
• vztah dávky záření a odpovědi MeSH
• záření gama škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH