Read by QxMD icon Read

gamma H2ax

Zhi-Yong He, Wen-Yue Wang, Wei-Yan Hu, Lu Yang, Yan Li, Wei-Yuan Zhang, Ya-Shu Yang, Si-Cheng Liu, Feng-Lan Zhang, Rong Mei, Da Xing, Zhi-Cheng Xiao, Ming Zhang
The PP2C family member Wild-type p53-induced phosphatase 1 (Wip1) critically regulates DNA damage response (DDR) under stressful situations. In the present study, we investigated whether Wip1 expression was involved in the regulation of DDR-induced and depression-related cellular senescence in mouse hippocampus. We found that Wip1 gene knockout (KO) mice showed aberrant elevation of hippocampal cellular senescence and of γ-H2AX activity, which is known as a biomarker of DDR and cellular senescence, indicating that the lack of Wip1-mediated γ-H2AX dephosphorylation facilitates cellular senescence in hippocampus...
September 30, 2016: Scientific Reports
Jayne Moquet, Stephen Barnard, Albena Staynova, Carita Lindholm, Octávia Monteiro Gil, Vanda Martins, Ute Rößler, Anne Vral, Charlot Vandevoorde, Maria Wojewódzka, Kai Rothkamm
PURPOSE: Within the EU RENEB project, seven laboratories have taken part in training and harmonisation activities to strengthen triage gamma-H2AX-based radiation exposure assessment. This has culminated in a second triage biodosimetry exercise. MATERIALS AND METHODS: Whole blood and separated lymphocyte samples were homogenously irradiated with (60)Co gamma rays at 0.5, 2.5 (blind samples), 0 and 2 Gy (reference samples). Following post-exposure incubations of 4 and 24 h, 16 samples were shipped on ice packs to each partner...
August 15, 2016: International Journal of Radiation Biology
D Ding, Y Zhang, J Wang, X Zhang, Y Gao, L Yin, Q Li, J Li, H Chen
Human peripheral blood lymphocytes (HPBLs) are one of the most sensitive cells to ionizing radiation (IR) in the human body, and IR-induced DNA damage and functional impairment of HPBLs are the adverse consequences of IR accidents and major side effects of radiotherapy. Phosphorylated H2AX (γH2AX) is a sensitive marker for DNA double-strand breaks, but the role and regulation of the pan-nuclear γH2AX response in HPBLs after IR remain unclear. We herein demonstrated that the pan-nuclear γH2AX signals were increased in a time- and dose-dependent manner, colocalized with >94% of TUNEL apoptotic staining, and displayed a typical apoptotic pattern in resting HPBLs after low LET X-ray IR...
2016: Cell Death Discovery
Ilgen Mender, Jerry W Shay
Telomerase maintains telomeric DNA in eukaryotes during early developments, ~90% of cancer cells and some proliferative stem like cells. Telomeric repeats at the end of chromosomes are associated with the shelterin complex. This complex consists of TRF1, TRF2, Rap1, TIN2, TPP1, POT1 which protect DNA from being recognized as DNA double-stranded breaks. Critically short telomeres or impaired shelterin proteins can cause telomere dysfunction, which eventually induces DNA damage responses at the telomeres. DNA damage responses can be identified by antibodies to 53BP1, gammaH2AX, Rad17, ATM, and Mre11...
November 20, 2015: Bio-protocol
Ki-Man Lee, Ui-Seob Lee, Eun-Hee Kim
An alpha particle irradiator has been built in the Radiation Bioengineering Laboratory at Seoul National University (SNU) to investigate the cellular responses to alpha emissions from radon and the progeny. This irradiator is designed to have the energy of alpha particles entering target cells similar to that of alpha emissions from the radon progeny Po-218 and Po-214 residing in the human respiratory tract. For the SNU alpha particle irradiator, an irradiation system is equipped with cell dishes of 4µm thick Mylar bottom and a special setup of cells on slide for gamma-H2AX assay...
September 2016: Applied Radiation and Isotopes
Johanna S Selvaratnam, Bernard Robaire
Advanced paternal age is linked to complications in pregnancy and genetic diseases in offspring. Aging results in excess reactive oxygen species (ROS) and DNA damage in spermatozoa; this damage can be transmitted to progeny with detrimental consequences. Although there is a loss of antioxidants with aging, the impact on aging male germ cells of the complete absence of either catalase (CAT) or superoxide dismutase 1 (SOD1) has not been investigated. We used CAT-null (Cat(-/-)) and SOD1-null (Sod(-/-)) mice to determine whether loss of these antioxidants increases germ cell susceptibility to redox dysfunction with aging...
September 2016: Biology of Reproduction
J Zámborszky, B Szikriszt, J Z Gervai, O Pipek, Á Póti, M Krzystanek, D Ribli, J M Szalai-Gindl, I Csabai, Z Szallasi, C Swanton, A L Richardson, D Szüts
Loss-of-function mutations in the BRCA1 and BRCA2 genes increase the risk of cancer. Owing to their function in homologous recombination repair, much research has focused on the unstable genomic phenotype of BRCA1/2 mutant cells manifest mainly as large-scale rearrangements. We used whole-genome sequencing of multiple isogenic chicken DT40 cell clones to precisely determine the consequences of BRCA1/2 loss on all types of genomic mutagenesis. Spontaneous base substitution mutation rates increased sevenfold upon the disruption of either BRCA1 or BRCA2, and the arising mutation spectra showed strong and specific correlation with a mutation signature associated with BRCA1/2 mutant tumours...
July 25, 2016: Oncogene
Anne-Laure Renault, Fabienne Lesueur, Yan Coulombe, Stéphane Gobeil, Penny Soucy, Yosr Hamdi, Sylvie Desjardins, Florence Le Calvez-Kelm, Maxime Vallée, Catherine Voegele, John L Hopper, Irene L Andrulis, Melissa C Southey, Esther M John, Jean-Yves Masson, Sean V Tavtigian, Jacques Simard
Approximately half of the familial aggregation of breast cancer remains unexplained. This proportion is less for early-onset disease where familial aggregation is greater, suggesting that other susceptibility genes remain to be discovered. The majority of known breast cancer susceptibility genes are involved in the DNA double-strand break repair pathway. ABRAXAS is involved in this pathway and mutations in this gene impair BRCA1 recruitment to DNA damage foci and increase cell sensitivity to ionizing radiation...
2016: PloS One
Yongxin Ji, Qina He, Yulong Sun, Jian Tong, Yi Cao
The aim of this study was to examine whether radiofrequency field (RF) preexposure induced adaptive responses (AR) in mouse bone-marrow stromal cells (BMSC) and the mechanisms underlying the observed findings. Cells were preexposed to 900-MHz radiofrequency fields (RF) at 120 μW/cm(2) power intensity for 4 h/d for 5 d. Some cells were subjected to 1.5 Gy γ-radiation (GR) 4 h following the last RF exposure. The intensity of strand breaks in the DNA was assessed immediately at 4 h. Subsequently, some BMSC were examined at 30, 60, 90, or 120 min utilizing the alkaline comet assay and γ-H2AX foci technique...
2016: Journal of Toxicology and Environmental Health. Part A
Jing Wang, Lina Yin, Junxiang Zhang, Yaping Zhang, Xuxia Zhang, Defang Ding, Yun Gao, Qiang Li, Honghong Chen
Establishing a rat model suitable for γ-H2AX biodosimeter studies has important implications for dose assessment of internal radionuclide contamination in humans. In this study, γ-H2AX, p-ATM and p-DNA-PKcs foci were enumerated using immunocytofluorescence method, and their protein levels were measured by Western blot in rat blood lymphocytes and granulocytes exposed to γ-rays compared with human blood lymphocytes and granulocytes. It was found that DNA double-strand break repair kinetics and linear dose responses in rat lymphocytes were similar to those observed in the human counterparts...
August 2016: Radiation and Environmental Biophysics
Yusuke Minakawa, Yuko Atsumi, Akira Shinohara, Yasufumi Murakami, Ken-Ichi Yoshioka
H2AX is expressed at very low levels in quiescent normal cells in vivo and in vitro. Such cells repair DNA double-strand breaks (DSBs) induced by γ-irradiation through a transient stabilization of H2AX. However, the resultant cells accumulate small numbers of irreparable (or persistent) DSBs via an unknown mechanism. We found that quiescent cells that had repaired DSBs directly induced by γ-rays were prone to accumulate DSBs during the subsequent DNA replication. Unlike directly induced DSBs, secondary DSBs were not efficiently repaired, although Rad51 and 53BP1 were recruited to these sites...
July 2016: Genes to Cells: Devoted to Molecular & Cellular Mechanisms
Bo Jiang, Shengqian Zhao, Zhen Tao, Jin Wen, Yancheng Yang, Yin Zheng, Hongling Yan, Ying Sheng, Aimin Gao
Using an in vitro model in which flatmounts of oesophagus was periodically exposed to bile acids, we demonstrate, using multiple methods, that the bile acid receptor TGR5, inducible nitric oxide synthase (iNOS) and γ-histone family 2A variant (γ-H2AX) are up-regulated. This indicates that bile acids cause up-regulation of iNOS, which further causes genotoxic stress as evidenced by increase of the highly sensitive marker, phosphorylated histone. In vitro nitric oxide (NO) assays showed increased production of nitric acid in the oesophageal epithelium exposed to the bile acids...
August 2016: Bioscience Reports
Yi Shi, Wei Wu, Huiping Qiao, Ling Yue, Lili Ren, Shuyu Zhang, Wei Yang, Zhanshan Yang
Severe acute radiation injuries are both very lethal and exceptionally difficult to treat. Though the radioresistant bacterium D. radiodurans was first characterized in 1956, genes and proteins key to its radioprotection have not yet to be applied in radiation injury therapy for humans. In this work, we express the D. radiodurans protein PprI in Pichia pastoris yeast cells transfected with the designed vector plasmid pHBM905A-pprI. We then treat human umbilical endothelial vein cells and BALB/c mouse cells with the yeast-derived PprI and elucidate the radioprotective effects the protein provides upon gamma irradiation...
2016: Scientific Reports
Rupak Pathak, Abdel Bachri, Sanchita P Ghosh, Igor Koturbash, Marjan Boerma, Regina K Binz, Jeffrey R Sawyer, Martin Hauer-Jensen
PURPOSE: Ionizing radiation (IR) generates reactive oxygen species (ROS), which cause DNA double-strand breaks (DSBs) that are responsible for cytogenetic alterations. Because antioxidants are potent ROS scavengers, we determined whether the vitamin E isoform γ-tocotrienol (GT3), a radio-protective multifunctional dietary antioxidant, can suppress IR-induced cytogenetic damage. METHODS: We measured DSB formation in irradiated primary human umbilical vein endothelial cells (HUVECs) by quantifying the formation of γ-H2AX foci...
September 2016: Pharmaceutical Research
Fatma Trabelsi, Rim Khlifi, Didier Goux, Marilyne Guillamin, Amel Hamza-Chaffai, François Sichel
As cadmium may be involved in the etiology of head and neck cancers, we investigated in the present work, the cytotoxic and genotoxic effects of Cd on human larynx cells. SQ20B cells were exposed to 25 and 50 μM Cd for 48 and 72 h. Results showed a dose-dependent decrease in cell viability, especially after 48 h, associated with mitochondria alterations as showed by transmission electronic microscopy. Surprisingly, the flow cytometry shows that the cells treated with Cd have a normal proliferative cycle like the untreated cell especially in G1 or G2 phase of cell cycle...
August 2016: Environmental Science and Pollution Research International
Emad A Ahmed, Eukene Vélaz, Michael Rosemann, Klaus-P Gilbertz, Harry Scherthan
Noncycling and terminally differentiated (TD) cells display differences in radiosensitivity and DNA damage response. Unlike other TD cells, Sertoli cells express a mixture of proliferation inducers and inhibitors in vivo and can reenter the cell cycle. Being in a G1-like cell cycle stage, TD Sertoli cells are expected to repair DSBs by the error-prone nonhomologous end-joining pathway (NHEJ). Recently, we have provided evidence for the involvement of Ku-dependent NHEJ in protecting testis cells from DNA damage as indicated by persistent foci of the DNA double-strand break (DSB) repair proteins phospho-H2AX, 53BP1, and phospho-ATM in TD Sertoli cells of Ku70-deficient mice...
May 2, 2016: Chromosoma
Nicola Alessio, Stefania Capasso, Giovanni Di Bernardo, Salvatore Cappabianca, Fiorina Casale, Anna Calarco, Marilena Cipollaro, Gianfranco Peluso, Umberto Galderisi
Following radiotherapy, bone sarcomas account for a significant percentage of recurring tumors. This risk is further increased in patients with hereditary retinoblastoma that undergo radiotherapy. We analyzed the effect of low and medium dose radiation on mesenchymal stromal cells (MSCs) with inactivated RB1 gene to gain insights on the molecular mechanisms that can induce second malignant neoplasm in cancer survivors. MSC cultures contain subpopulations of mesenchymal stem cells and committed progenitors that can differentiate into mesodermal derivatives: adipocytes, chondrocytes, and osteocytes...
April 28, 2016: Cell Cycle
Ute Maucksch, Roswitha Runge, Gerd Wunderlich, Robert Freudenberg, Anne Naumann, Jörg Kotzerke
PURPOSE: In addition to gamma radiation, (99m)Tc emits low-energy Auger electrons with path-lengths of nanometers to micrometers that cannot be utilized for diagnostic procedures; however, they have frequently been discussed for therapeutic applications. We compared radiotoxicity of three (99m)Tc-labeled radiopharmaceuticals with differences in the subcellular distribution. MATERIALS AND METHODS: The intracellular radionuclide uptake and subcellular distribution of [(99m)Tc]-pertechnetate ((99m)Tc-pertechnetate), [(99m)Tc]Tc-hexamethyl-propylene-aminoxime ((99m)Tc-HMPAO) and [(99m)Tc]Tc-hexakis-2-methoxyisobutylisonitrile ((99m)Tc-MIBI) were quantified in rat thyroid FRTL-5 cells...
April 27, 2016: International Journal of Radiation Biology
Vinay Jain, P R Vivek Kumar, P K M Koya, G Jaikrishan, Birajalaxmi Das
The high level natural radiation area (HLNRA) of Kerala is a 55km long and 0.5km wide strip in south west coast of India. The level of background radiation in this area varies from <1.0mGy/year to 45.0mGy/year. It offers unique opportunity to study the effect of chronic low dose/low dose-rate radiation directly on human population. Spontaneous level of DNA double strand breaks (DSBs) was quantified in peripheral blood mononuclear cells of 91 random individuals from HLNRA (N=61, mean age: 36.1±7.43years) and normal level natural radiation area (NLNRA) (N=30, mean age: 35...
June 2016: Mutation Research
Xiang Hong Li, Cam T Ha, Mang Xiao
We previously reported that microRNA-30 (miR-30) expression was initiated by radiation-induced proinflammatory factor IL-1β and NFkB activation in mouse and human hematopoietic cells. However, the downstream effectors of miR-30 and its specific role in radiation-induced cell death are not well understood. In the present study, we evaluated effects of radiation on miR-30 expression and activation of intrinsic apoptotic pathway Bcl-2 family factors in in vivo mouse and in vitro human hematopoietic cells. CD2F1 mice and human CD34+ cells were exposed to different doses of gamma-radiation...
June 2016: Apoptosis: An International Journal on Programmed Cell Death
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"