Abstract：
:Trypanothione is a unique diglutathionyl-spermidine conjugate found in abundance in trypanosomes but not in other eukaryotes. Because trypanothione is a naturally occurring polyamine thiol reminiscent of the synthetic drug amifostine, it may be a useful protector against radiation and oxidative stress. For these reasons we hypothesized that trypanothione might serve as a radioprotective agent when produced in bacteria. To accomplish this objective, the trypanothione synthetase and reductase genes from T. cruzi were introduced into E. coli and their expression was verified by qPCR and immunoblotting. Trypanothione synthesis in bacteria, detected by HPLC, resulted in decreased intracellular levels of reactive oxygen species as determined by H(2)DCFDA oxidation. Moreover, E. coli genomic DNA was protected from radiation-induced DNA damage by 4.6-fold in the presence of trypanothione compared to control bacteria. Concordantly, the transgenic E. coli expressing trypanothione were 4.3-fold more resistant to killing by (137)Cs gamma radiation compared to E. coli devoid of trypanothione expression. Thus we have shown for the first time that E. coli can be genetically engineered to express the trypanothione biosynthetic pathway and produce trypanothione, which results in their radioresistance. These results warrant further research to explore the possibility of developing trypanothione as a novel radioprotective agent.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Fitzgerald MP,Madsen JM,Coleman MC,Teoh ML,Westphal SG,Spitz DR,Radi R,Domann FEdoi
10.1667/RR2235.1subject
Has Abstractpub_date
2010-09-01 00:00:00pages
290-6issue
3eissn
0033-7587issn
1938-5404journal_volume
174pub_type
杂志文章abstract：:To characterize the differences in the radiosensitivity of individual populations of human hematopoietic stem/progenitor cells (HSPCs), we examined the relationship among cell surface antigens, clonogenic potential and radiation survival. The expressions of CD34, CD38, CD45RA, CD110 and Tie-2, early differentiation pa...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1839.1
更新日期：2010-02-01 00:00:00
abstract：:Chinese hamster ovary cells were irradiated with 250 kVp X rays and analyzed for the presence of DNA double-strand breaks using either polycarbonate filter elution or pulsed-field agarose gel electrophoresis at neutral pH. Reduction in DNA length detected by filter elution was produced as a nonlinear function of incre...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-12-01 00:00:00
abstract：:The risk of a radiological or nuclear public health emergency is a major growing concern of the U.S. government. To address a potential incident and ensure that the government is prepared to respond to any subsequent civilian or military casualties, the U.S. Department of Health and Human Services and the Department o...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR15137.1
更新日期：2018-12-01 00:00:00
abstract：:The immunocytochemical response to DNA damage induced by low-energy bismuth and carbon ions was investigated in normal human fibroblasts. Inside the nuclei, the traversing charged particles lead to the accumulation of proteins related to DNA lesions and repair along the ion trajectories. Irradiation under a standard g...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2003)159[0676:biohct]2.0.co;2
更新日期：2003-05-01 00:00:00
abstract：:The cellular sites for damage in mammalian cells caused by 193-nm radiation from an argon fluoride excimer laser were investigated. The ability of Chinese hamster ovary cells to reduce a tetrazolium dye (MTT) was decreased to 37% of unirradiated control by 2.5 x 10(3) J/m2 of 193-nm radiation when measured either 4 or...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-05-01 00:00:00
abstract：:Aqueous solutions of calf thymus deoxyribonucleic acid (DNA) were exposed to hydrogen peroxide in the presence of air. Base products formed in DNA were identified and quantitated following acid hydrolysis and trimethylsilylation using gas chromatography-mass spectrometry. The yields of these products were dependent up...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-03-01 00:00:00
abstract：:Comparatively high exposures to power-frequency electric and magnetic fields produce established biological effects that are explained by accepted mechanisms and that form the basis of exposure guidelines. Lower exposures to magnetic fields (< 1 microT average in the home) are classified as "possibly carcinogenic" on ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3522.1
更新日期：2006-04-01 00:00:00
abstract：:The Escherichia coli nth gene encodes endonuclease III, which catalyses the glycolytic removal of various oxidized thymine residues from DNA. A truncated version of nth, with the prokaryotic regulatory sequences removed, was ligated into the retrovirus-based vector pZipneoSV(X)1 and transfected into the radiosensitive...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1992-10-01 00:00:00
abstract：:Radioprotection in vitro by sulfhydryl (SH)-containing compounds is usually greater in aerated than in hypoxic cells. This observation has been cited recently as one of the reasons for the relatively greater effectiveness of radioprotectors such as WR-2721 in normal tissues compared to tumor cells. It is demonstrated ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1985-03-01 00:00:00
abstract：:Hyperthermia sensitization or tolerance is subject to cellular events that may occur at membrane, nuclear, and cytoplasmic sites. We have studied the effects of elevated temperatures on the oxidative-reductive state of the cell by measuring and altering glutathione (GSH) concentrations. GSH plays a pivotal role in mai...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1983-09-01 00:00:00
abstract：:Astronauts traveling outside Earth's magnetosphere risk exposure to charged particle radiation that may cause neurophysiological changes and behavioral deficits. Although proton particles comprise a large portion of the space radiation environment, little has been published on the effects of low-dose proton radiation ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr13903.1
更新日期：2015-08-01 00:00:00
abstract：:The influence of Trp53 on the radiation-induced elevation of T-cell receptor (TCR) variant fractions was examined in splenic T lymphocytes of Trp53-proficient and -deficient mice. Wild-type Trp53+/+, heterozygous Trp53+/- and null Trp53-/- mice were exposed to 3 Gy of X rays at 8 weeks of age. The fraction of TCR-defe...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR3583.1
更新日期：2006-07-01 00:00:00
abstract：:A radiation-induced bystander response, which is generally defined as a cellular response that is induced in nonirradiated cells that received bystander signals from directly irradiated cells within an irradiated cell population. In our earlier X-ray microbeam studies, bystander cell killing in normal human fibroblast...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR3010.1
更新日期：2013-02-01 00:00:00
abstract：:Cellular nonprotein thiols (NPSH) consist of glutathione (GSH) and other low molecular weight species such as cysteine, cysteamine, and coenzyme A. GSH is usually less than the total cellular NPSH, and with thiol reactive agents, such as diethyl maleate (DEM), its rate of depletion is in part dependent upon the cellul...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1983-09-01 00:00:00
abstract：:Radiation nephropathy is one of the common late effects in cancer survivors who received radiotherapy as well as in victims of radiation accidents. The clinical manifestations of radiation nephropathy occur months after exposure. To date, there are no known early biomarkers to predict the future development of radiati...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR14828.1
更新日期：2017-12-01 00:00:00
abstract：:Incorporation of bromodeoxyuridine (BrdU) into DNA in both Chinese hamster ovary (CHO) cells and human melanoma (U1) cells reduced the rate of DNA migration in transverse alternating-field electrophoresis (TAFE) agarose gel optimized for separating molecules larger than 2 Mb. This "BrdU migration effect" was independe...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-04-01 00:00:00
abstract：:We present theoretical arguments to explain observations of a "reversal" of the RBE at relatively large doses; that is, the RBE of high-LET vs low-LET radiation is less than one. Numerical examples are given and the results of Bogo et al. (Radiat. Res. 118, 341-352, 1989) are discussed qualitatively. ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1992-04-01 00:00:00
abstract：:Radiation exposure causes DNA breaks leading to structural chromosome aberrations that can be carcinogenic. Lifetime cancer risks are elevated in irradiated children compared to similarly exposed adults. To determine the extent to which age influences the frequency and types of chromosome damage in response to ionizin...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR13598.1
更新日期：2014-06-01 00:00:00
abstract：:The placental transfer and distribution of 241Am in the feto-placental system were studied in pregnant rats. Rats were injected intravenously with 241Am citrate at 15 or 18 days of gestation. Groups injected at 15 days of gestation were sacrificed 2, 24, 48, or 120 hr after injection, and the group injected at 18 days...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1983-04-01 00:00:00
abstract：:The use of tritium-labeled thymidine (3H-TdR) in biological research made it necessary to develop a quick and accurate method for determination of tritium activity in tissue. After 3H-TdR incorporation into the root tip meristem of Vicia faba, total 3H activity as well as 3H-DNA activity was measured by liquid scintil...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1968-12-01 00:00:00
abstract：:Electron microbeam experiments are planned or under way to explore in part the question regarding whether the bystander effect is a general phenomenon or is restricted to high-LET radiation. Since low-LET radiations scatter more readily compared to high-LET radiations, identifying bystander cells and assessing the pot...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2001)155[0089:moakem]2.0.co;2
更新日期：2001-01-01 00:00:00
abstract：:Evidence is presented for the formation of products in irradiated dinucleoside monophosphates in which both bases are damaged. The dinucleoside monophosphates d(GpT), d(GpC), d(TpG) and d(CpG) were X-irradiated in oxygenated aqueous solution. Product identification was by NMR spectroscopy. In products containing doubl...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1995-01-01 00:00:00
abstract：:Nearly 2% of the male population of Estonia aged 20-39 years were sent to Chernobyl to assist in the cleanup activities after the reactor accident. A cohort of 4,833 cleanup workers was assembled based on multiple and independent sources of information. Information obtained from 3,704 responses to a detailed questionn...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1997-05-01 00:00:00
abstract：:Exposure to ionizing radiation alone or combined with traumatic tissue injury is a crucial life-threatening factor in nuclear and radiological incidents. Radiation injuries occur at the molecular, cellular, tissue and systemic levels; their mechanisms, however, remain largely unclear. Exposure to radiation combined wi...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR14647.1
更新日期：2017-11-01 00:00:00
abstract：:We have manipulated the extracellular Ca2+ concentration (1.8 mM in normal Dulbecco's modified Eagle's medium) to test whether the resulting effect on intracellular free Ca2+ homeostasis was similar in heat-sterilized and nonheated mouse NIH-3T3 cells. The responsiveness of the intracellular free Ca2+ concentration to...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-10-01 00:00:00
abstract：:A nested case-control study was conducted among workers at five U.S. nuclear facilities to evaluate leukemia mortality risk (excluding chronic lymphocytic) from ionizing radiation using worksite doses and adjusting for potential confounding. Conditional logistic regression was used to estimate the relative risk (RR) o...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr0724.1
更新日期：2007-02-01 00:00:00
abstract：:Radiation-induced apoptosis in lymphocyte-derived cell lines is characterized by endonucleolytic cleavage of cellular DNA within hours after radiation exposure. We have studied this phenomenon qualitatively (DNA gel electrophoresis) and quantitatively (diphenylamine reagent assay) in murine EL4 T-lymphoma cells expose...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1995-03-01 00:00:00
abstract：:Radiotherapy is one of the major treatment modalities for the management of various cancers, however, it is limited by the severe side effects and complications experienced by some patients. Nicaraven, a chemically synthesized hydroxyl radical-specific scavenger, has been shown to protect normal tissues from radiation...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR14614.1
更新日期：2017-02-22 00:00:00
abstract：:These studies examined the effects of X radiation and interleukin 3 (IL-3), which is an effective cytokine for the generation of megakaryocytopoiesis from X-irradiated hematopoietic stem/progenitor cells, on the terminal process of human megakaryocytopoiesis and thrombopoiesis. Mature megakaryocytes were induced by cu...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1519.1
更新日期：2009-09-01 00:00:00
abstract：:Infusions of boronophenylalanine-fructose complex (BPA-F), at doses up to 900 mg/kg of BPA and 860 mg/kg of fructose, have been used to deliver boron to cancer tissue for boron neutron capture therapy (BNCT). In patients with phenylketonuria (PKU), phenylalanine accumulates, which is harmful in the long run. PKU has b...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3067
更新日期：2003-11-01 00:00:00
