1
|
Hatano Y, Nakamura H, Fujiwara S, Saito S, Kenmotsu T. Damages of DNA in tritiated water. Enzymes 2022; 51:131-152. [PMID: 36336406 DOI: 10.1016/bs.enz.2022.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Tritium is a radioisotope of hydrogen emitting low energy β-rays in disintegration to 3He. DNA molecules are damaged mainly by β-ray irradiation, and additional damages can be induced by break of chemical bond by nuclear transmutation to inert 3He. Deep knowledges of the mechanisms underlying DNA damages lead to better understanding of biological effects of tritium. This chapter reviews recent experimental and computer simulation activities on quantitative evaluation of damage rates by β-ray irradiation and nuclear transmutation. The rate of DNA double-strand breaks in tritiated water has been examined using a single molecule observation method. The effects of β-ray irradiation were not noticeable at the level of tritium concentration of ∼kBq/cm3, while the irradiation effects were clear at tritium concentrations of ∼MBq/cm3. The factors affecting on the DSB rate are discussed. A new image processing method for the automatic measurement of DNA length using OpenCV and deep learning is also introduced. The effects of tritium transmutation on hydrogen bonds acting between the two main strands of DNA have been examined using molecular dynamics simulations. The study showed that the collapsing of DNA structure by the transmutation can be quantitatively evaluated using the root mean square deviation of atomic positions.
Collapse
Affiliation(s)
- Yuji Hatano
- Hydrogen Isotope Research Center, University of Toyama, Toyama, Japan.
| | - Hiroaki Nakamura
- National Institute for Fusion Science, Toki, Japan; Graduate School of Engineering, Nagoya University, Nagoya, Japan
| | - Susumu Fujiwara
- Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Kyoto, Japan
| | - Seiki Saito
- Graduate School of Science and Engineering, Yamagata University, Yamagata, Japan
| | - Takahiro Kenmotsu
- Faculty of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| |
Collapse
|
2
|
Yoshikawa K. Quantitative evaluation of DNA double-strand breaks (DSBs) through single-molecule observation. Enzymes 2022; 51:7-27. [PMID: 36336410 DOI: 10.1016/bs.enz.2022.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
By adapting the method of single molecular observation for individual DNAs, it will be shown that reliable analysis of double-strand breaks, DSBs, becomes possible for various kinds of damage sources. Single DNA above the size of several-tens kilo base-pairs exhibits the length scale above several μm, indicating that their whole conformation is visible with fluorescence microscopy by adding suitable fluoresce dye to the solution. Various examples of the quantitative evaluation on DSBs are described, together with the evaluation of the protective effects of anti-oxidants.
Collapse
Affiliation(s)
- Kenichi Yoshikawa
- Faculty of Life and Medical Sciences, Doshisha University, Kyoto, Japan; Center for Integrative Medicine and Physics, Institute for Advanced Study, Kyoto University, Kyoto, Japan.
| |
Collapse
|
3
|
Ma Y, Akiyama I. Mechanical force induced DNA double-strand breaks: Ultrasound. Enzymes 2022; 51:53-63. [PMID: 36336408 DOI: 10.1016/bs.enz.2022.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Since the application of ultrasound for clinical diagnosis and therapeutic purposes has been increased rapidly, the effects of exposure to ultrasound on DNA molecules were studied. In this chapter, we introduced various effects of DNA damages caused by different conditions of exposure of ultrasound. Ultrasound with different sound pressure and pulse transmission conditions have been applied in our study. We discussed the threshold of sound pressure of ultrasound-induced DNA damages. Different kinds of pulses of ultrasound and microbubbles' influences on DNA double-strand breaks were also shown.
Collapse
Affiliation(s)
- Yue Ma
- Faculty of Life and Medical Science, Doshisha University, Kyotanabe, Japan; Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China.
| | - Iwaki Akiyama
- Faculty of Life and Medical Science, Doshisha University, Kyotanabe, Japan
| |
Collapse
|
4
|
Ma Y, Ishihara K, Yoshida K, Akiyama I, Yoshikawa K. Double-strand breaks in genome-sized DNA caused by megahertz ultrasound. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2021; 150:241. [PMID: 34340483 DOI: 10.1121/10.0005539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 06/16/2021] [Indexed: 06/13/2023]
Abstract
Double-strand breaks (DSBs) of giant DNA molecules after exposure to 1.0 MHz pulsed-wave ultrasound were quantitatively evaluated by single-molecule observation of giant DNA (T4 GT7 DNA; 166 kbp) through fluorescence microscopy. Aqueous solutions of DNA were exposed to ultrasonic waves with different sound pressures, repetition periods (1, 2, 5 ms), and pulse durations (5, 10, 50 μs). Below a threshold value of sound pressure, almost no double-strand breaks were generated, and above the threshold, the degree of damage increased in an accelerated manner as the pressure increased. DNA damage was much more severe for exposure to ultrasound with a shorter pulse duration. In addition, a longer pulse repetition period caused worse damage in DNA molecules. The effect of microbubbles on the damage induced by exposure to ultrasound had also been studied. While a result showed that a very small amount of microbubbles increased DSBs of DNA, this effect of microbubbles only weakly depended on their concentrations.
Collapse
Affiliation(s)
- Yue Ma
- Faculty of Life and Medical Science, Doshisha University, Kyotanabe, 6100394, Japan
| | - Kazuya Ishihara
- Faculty of Science and Engineering, Doshisha University, Kyotanabe, 6100394, Japan
| | - Kenji Yoshida
- Center for Frontier Medical Engineering, Chiba University, Chiba, 2638522, Japan
| | - Iwaki Akiyama
- Faculty of Life and Medical Science, Doshisha University, Kyotanabe, 6100394, Japan
| | - Kenichi Yoshikawa
- Faculty of Life and Medical Science, Doshisha University, Kyotanabe, 6100394, Japan
| |
Collapse
|
5
|
Zh G, R F, G H H, A D, A K, Z H. Histopathologic Evaluation of Radio-Protective Effect of Hesperidin on the Liver of Sprague Dawely Rats. J Biomed Phys Eng 2020; 10:7-14. [PMID: 32158707 PMCID: PMC7036407 DOI: 10.31661/jbpe.v0i0.832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 12/04/2017] [Indexed: 11/21/2022]
Abstract
BACKGROUND Hesperidin is a bioflavonoid glycoside mainly found in citrus fruit and has been shown radio-protective potential in various measurement systems. OBJECTIVE In this article aims to investigate the radio-protective effect of hesperidin on the liver of Sprague Dawely rats. MATERIAL AND METHODS In this clinical study, 40 male rats were selected randomly and divided into 8 groups. Group 1 did not receive radiation and hesperidin (sham control). Group 2 received only 100 mg/kg body weight (b.w) of hesperidin for 7 consecutive days (HES group); group 3 exposed to dose of 2Gy whole body gamma radiation (2Gy group), and group 4 and 5 received 50 and 100 mg/kg b.w of HES for 7 consecutive days before 2 Gy gamma radiation, respectively.Group 6 exposed to dose of 8Gy gamma radiation (8Gy group); group 7 and 8 received 50 and 100 mg/kg b.w of HES for 7 days before 8Gy gamma irradiation, respectively. Histopathological evaluation was perfomred 24 hours after radiation. RESULTS Administration of hesperidin (50 mg/kg b.w, 7 days) before 2Gy of gamma irradiation led to remove inflammatory mononuclear cells in the portal space. Microscopic findings in the groups receiving two doses of hesperidin (50 and 100 mg/kg b.w, orally, 7 days), before 8Gy of gamma radiation, were similar in a way that extreme dilation of central veins to be seen, however, there was no capillarization. CONCLUSION HES can be offered as a suitable radio-protector in radiotherapy patients and radiation workers.
Collapse
Affiliation(s)
- Ghorbani Zh
- MSc, Radiology Department, School of Paramedicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fardid R
- PhD, Radiology Department, School of Paramedicine, Shiraz University of Medical Sciences, Shiraz, Iran
- PhD, Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), School of Paramedicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Haddadi G H
- PhD, Radiology Department, School of Paramedicine, Shiraz University of Medical Sciences, Shiraz, Iran
- PhD, Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), School of Paramedicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Derakhshanfar A
- PhD, Diagnostic Laboratory Sciences and Technology Research Center, Basic Sciences in Infection Diseases Research Center, Center of Comparative & Experimental Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Kouhpayeh A
- PhD, Department of Pharmacology, Fasa University of Medical Science, Fasa, Iran
| | - Haddadi Z
- MD, Medical student, Student Research Committee, Fasa University of Medical Sciences, Fasa, Iran
| |
Collapse
|
6
|
Hatano Y, Konaka Y, Shimoyachi H, Kenmotsu T, Oya Y, Nakamura H. Kinetics of double strand breaks of DNA in tritiated water evaluated using single molecule observation method. FUSION ENGINEERING AND DESIGN 2019. [DOI: 10.1016/j.fusengdes.2018.11.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
7
|
Noda M, Ma Y, Yoshikawa Y, Imanaka T, Mori T, Furuta M, Tsuruyama T, Yoshikawa K. A single-molecule assessment of the protective effect of DMSO against DNA double-strand breaks induced by photo-and γ-ray-irradiation, and freezing. Sci Rep 2017; 7:8557. [PMID: 28819291 PMCID: PMC5561226 DOI: 10.1038/s41598-017-08894-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/14/2017] [Indexed: 11/09/2022] Open
Abstract
Dimethyl sulfoxide (DMSO) is widely used as a cryoprotectant for organs, tissues, and cell suspension in storage. In addition, DMSO is known to be a useful free radical scavenger and a radio-protectant. To date, many in vitro assays using cultured cells have been performed for analysing the protective effect of DMSO against genomic DNA damage; however, currently it has been rather difficult to detect DNA double strand breaks (DSBs) in a quantitative manner. In the present study, we aimed to observe the extent of DNA damage by use of single molecular observation with a fluorescence microscope to evaluate DSBs induced by photo- and γ-ray-irradiation, or freeze/thawing in variable concentrations of DMSO. As a result, we found that 2% DMSO conferred the maximum protective effect against all of the injury sources tested, and these effects were maintained at higher concentrations. Further, DMSO showed a significantly higher protective effect against freezing-induced damage than against photo- and γ-ray-irradiation-induced damage. Our study provides significant data for the optimization of DNA cryopreservation with DMSO, as well as for the usage of DNA as the protective agent against the injuries caused by active oxygen and radiations.
Collapse
Affiliation(s)
- Masami Noda
- Faculty of Life and Medical Sciences, Doshisha University, Kyoto, 610-0321, Japan
| | - Yue Ma
- Faculty of Life and Medical Sciences, Doshisha University, Kyoto, 610-0321, Japan
| | - Yuko Yoshikawa
- Faculty of Life and Medical Sciences, Doshisha University, Kyoto, 610-0321, Japan
| | - Tadayuki Imanaka
- Research Organization of Science and Technology, Ritsumeikan University, Shiga, 525-8577, Japan
| | - Toshiaki Mori
- Graduate School of Engineering, Department of Quantum and Radiation Technology, Osaka Prefecture University, Osaka, 599-8570, Japan
| | - Masakazu Furuta
- Graduate School of Engineering, Department of Quantum and Radiation Technology, Osaka Prefecture University, Osaka, 599-8570, Japan
| | - Tatsuaki Tsuruyama
- Drug Discovery and Medicine, Department of Pathology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Kenichi Yoshikawa
- Faculty of Life and Medical Sciences, Doshisha University, Kyoto, 610-0321, Japan.
| |
Collapse
|
8
|
Ma Y, Ogawa N, Yoshikawa Y, Mori T, Imanaka T, Watanabe Y, Yoshikawa K. Protective effect of ascorbic acid against double-strand breaks in giant DNA: Marked differences among the damage induced by photo-irradiation, gamma-rays and ultrasound. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.08.054] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
9
|
Iranshahi M, Rezaee R, Parhiz H, Roohbakhsh A, Soltani F. Protective effects of flavonoids against microbes and toxins: The cases of hesperidin and hesperetin. Life Sci 2015; 137:125-32. [PMID: 26188593 DOI: 10.1016/j.lfs.2015.07.014] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/13/2015] [Accepted: 07/11/2015] [Indexed: 10/23/2022]
Abstract
Many plants produce flavonoids as secondary metabolites. These organic compounds may be involved in the defense against plant-threatening factors, such as microbes and toxins. Certain flavonoids protect their origin source against plant pathogens, but they also exhibit potential healthy properties in human organisms. Hesperidin (Hsd) and its aglycone, hesperetin (Hst), are two flavonoids from the Citrus species that exhibit various biological properties, including antioxidant, antiinflammatory and anticancer effects. Recent studies indicated that Hst and Hsd possess antimicrobial activity. Although the exact mechanisms behind their antimicrobial properties are not fully understood, several mechanisms such as the activation of the host immune system, bacterial membrane disruption, and interference with microbial enzymes, have been proposed. Hsd and Hst may also have protective effects against toxicity induced by various agents. These natural substances may contribute to the protection of cells and tissues through their antioxidant and radical scavenging activities. This review discusses the protective activities of Hsd and Hst against microbes and several toxicities induced by oxidants, chemicals, toxins, chemotherapy and radiotherapy agents, which were reported in vitro and in vivo. Furthermore, the probable mechanisms behind these activities are discussed.
Collapse
Affiliation(s)
- Mehrdad Iranshahi
- Biotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ramin Rezaee
- Department of Physiology and Pharmacology, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Hamideh Parhiz
- Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmaceutical Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Roohbakhsh
- Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Fatemeh Soltani
- Biotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmaceutical Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
| |
Collapse
|
10
|
Shimobayashi SF, Iwaki T, Mori T, Yoshikawa K. Probability of double-strand breaks in genome-sized DNA by γ-ray decreases markedly as the DNA concentration increases. J Chem Phys 2013; 138:174907. [PMID: 23656159 DOI: 10.1063/1.4802993] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
By use of the single-molecule observation, we count the number of DNA double-strand breaks caused by γ-ray irradiation with genome-sized DNA molecules (166 kbp). We find that P1, the number of double-strand breaks (DSBs) per base pair per unit Gy, is nearly inversely proportional to the DNA concentration above a certain threshold DNA concentration. The inverse relationship implies that the total number of DSBs remains essentially constant. We give a theoretical interpretation of our experimental results in terms of attack of reactive species upon DNA molecules, indicating the significance of the characteristics of genome-sized giant DNA as semiflexible polymers for the efficiency of DSBs.
Collapse
|
11
|
O’Sullivan A, O’Callaghan Y, O’Grady M, Hayes M, Kerry J, O’Brien N. The effect of solvents on the antioxidant activity in Caco-2 cells of Irish brown seaweed extracts prepared using accelerated solvent extraction (ASE®). J Funct Foods 2013. [DOI: 10.1016/j.jff.2013.02.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
|
12
|
Yoshikawa Y, Mori T, Suzuki M, Imanaka T, Yoshikawa K. Comparative study of kinetics on DNA double-strand break induced by photo- and gamma-irradiation: Protective effect of water-soluble flavonoids. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.11.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
|
14
|
Le Scodan R, Cizeron-Clairac G, Fourme E, Meseure D, Vacher S, Spyratos F, de la Lande B, Cvitkovic F, Lidereau R, Bieche I. DNA repair gene expression and risk of locoregional relapse in breast cancer patients. Int J Radiat Oncol Biol Phys 2010; 78:328-36. [PMID: 20092964 DOI: 10.1016/j.ijrobp.2009.07.1735] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Revised: 07/21/2009] [Accepted: 07/23/2009] [Indexed: 11/28/2022]
Abstract
PURPOSE Radiation therapy appears to kill cells mainly by inducing DNA double-strand breaks. We investigated whether the DNA repair gene expression status might influence the risk of locoregional recurrence (LRR) in breast cancer patients. METHODS AND MATERIALS We used a quantitative reverse transcriptase PCR-based approach to measure messenger RNA levels of 20 selected DNA repair genes in tumor samples from 97 breast cancer patients enrolled in a phase III trial (Centre René Huguenin cohort). Normalized mRNA levels were tested for an association with LRR-free survival (LRR-FS) and overall survival (OS). The findings were validated in comparison with those of an independent cohort (Netherlands Cancer Institute (NKI) cohort). Multivariate analysis encompassing known prognostic factors was used to assess the association between DNA repair gene expression and patient outcome. RESULTS RAD51 was the only gene associated with LRR in both cohorts. With a median follow-up of 126 months in the CRH cohort, the 5-year LRR-FS and OS rates were 100% and 95% in the 61 patients with low RAD51 expression, compared with 70% and 69% in the 36 patients with high RAD51 expression, respectively (p < 0.001). RAD51 overexpression was associated with a higher risk of LRR (hazard ratio [HR], 12.83; 95% confidence interval [CI], 3.6-45.6) and death (HR, 4.10; 95% CI, 1.7-9.7). RAD51 overexpression was also significantly associated with shorter LRR-FS and OS in the NKI cohort. CONCLUSIONS Overexpression of RAD51, a key component of the homologous DNA repair pathway, is associated with poor breast cancer outcome. This finding warrants prospective studies of RAD51 as a prognosticator and therapeutic target.
Collapse
Affiliation(s)
- Romuald Le Scodan
- Department of Radiation Oncology, Centre René Huguenin, Saint Cloud, France.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Saha RK, Takahashi T, Suzuki T. Glucosyl hesperidin prevents influenza a virus replication in vitro by inhibition of viral sialidase. Biol Pharm Bull 2009; 32:1188-92. [PMID: 19571383 DOI: 10.1248/bpb.32.1188] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Hesperidin, a flavonoid obtained from citrus fruits, is known to have multiple biological activities and antimicrobial activities for human viruses; however, hesperidin has very low solubility in water and the target molecule of hesperidin for influenza virus remains unknown. A water-soluble derivative of hesperidin, glucosyl hesperidin (GH), which was synthesized by regioselective transglycosylation with cyclodextrin glucanotransferase, has been reported to have biological activities that are as or stronger than those of hesperidin. To determine the inhibitory effect of GH on influenza A virus (IAV) infection, Madin-Darby canine kidney (MDCK) cells were treated with GH before, at the same time as, and after IAV inoculation. GH treatment before IAV inoculation had no effect on virus replication, whereas, treatment with GH at the same time as or after IAV inoculation induced distinct reduction in IAV replication. Inhibition analysis of GH against two surface glycoprotein spikes of IAV revealed that GH prevents IAV replication by inhibition of viral sialidase activity that is involved in the entry and release stages on IAV infection but not by receptor binding inhibition. GH had no cytotoxic effects on MDCK cells in a dose range of 0-25 mM. Our results provide useful information for the development of novel sialidase inhibitors for influenza prevention.
Collapse
Affiliation(s)
- Repon Kumer Saha
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka
| | | | | |
Collapse
|
16
|
Hosseinimehr SJ, Nemati A. Radioprotective effects of hesperidin against gamma irradiation in mouse bone marrow cells. Br J Radiol 2006; 79:415-8. [PMID: 16632622 DOI: 10.1259/bjr/40692384] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The radioprotective effects of hesperidin (HES), a flavonone glucoside, were investigated by using the micronucleus test for anticlastogenic and cell proliferation activity. A single intraperitoneal (ip) administration of hesperidin at doses of 10 mg kg(-1), 20 mg kg(-1), 40 mg kg(-1), 80 mg kg(-1) and 160 mg kg(-1) 45 min prior to gamma irradiation (2 Gy) reduced the frequencies of micronuleated polychromatic erythrocytes (MnPCEs). All five doses of HES significantly reduced the frequencies of MnPCEs and increased PCE/PCE+NCE ratio in mice bone marrow compared with non-drug-treated irradiated control (p<0.0001). There was a drug dose-response effect of HES in reducing MnPCE and increasing the PCE/PCE+NCE ratio in bone marrow cells. The maximum reduction in MnPCE was observed in mice treated with HES at a dose of 80 mg kg(-1). The total MnPCE values were 2.85 fold less in the 80 mg kg(-1) HES group after being exposed to 2 Gy of gamma-rays than those in the respective irradiated control. Our study demonstrates that hesperidin has powerful protective effects on the radiation-induced DNA damage and on the decline in cell proliferation in mouse bone marrow.
Collapse
Affiliation(s)
- S J Hosseinimehr
- Department of Medicinal Chemistry, Faculty of Pharmacy, Mazandarn University of Medical Sciences, Sari, Iran
| | | |
Collapse
|
17
|
Abstract
DNA and RNA are the most individual molecules known. Therefore, single-molecule experiments with these nucleic acids are particularly useful. This review reports on recent experiments with single DNA and RNA molecules. First, techniques for their preparation and handling are summarised including the use of AFM nanotips and optical or magnetic tweezers. As important detection techniques, conventional and near-field microscopy as well as fluorescence resonance energy transfer (FRET) and fluorescence correlation spectroscopy (FCS) are touched on briefly. The use of single-molecule techniques currently includes force measurements in stretched nucleic acids and in their complexes with binding partners, particularly proteins, and the analysis of DNA by restriction mapping, fragment sizing and single-molecule hybridisation. Also, the reactions of RNA polymerases and enzymes involved in DNA replication and repair are dealt with in some detail, followed by a discussion of the transport of individual nucleic acid molecules during the readout and use of genetic information and during the infection of cells by viruses. The final sections show how the enormous addressability in nucleic acid molecules can be exploited to construct a single-molecule field-effect transistor and a walking single-molecule robot, and how individual DNA molecules can be used to assemble a single-molecule DNA computer.
Collapse
Affiliation(s)
- Karl Otto Greulich
- Institute of Molecular Biotechnology, Beutenbergstr. 11, 07745 Jena, Germany.
| |
Collapse
|
18
|
Yoshikawa Y, Hizume K, Oda Y, Takeyasu K, Araki S, Yoshikawa K. Protective effect of vitamin C against double-strand breaks in reconstituted chromatin visualized by single-molecule observation. Biophys J 2005; 90:993-9. [PMID: 16284271 PMCID: PMC1367124 DOI: 10.1529/biophysj.105.069963] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Direct attack to genomic DNA by reactive oxygen species causes various types of lesions, including base modifications and strand breaks. The most significant lesion is considered to be an unrepaired double-strand break that can lead to fatal cell damage. We directly observed double-strand breaks of DNA in reconstituted chromatin stained by a fluorescent cyanine dye, YOYO (quinolinium, 1,1'-[1,3- propanediylbis[(dimethyliminio)-3,1- propanediyl]]bis[4-[(3-methyl-2(3H)-benzoxazolylidene)methyl]]-, tetraiodide), in solution, where YOYO is known to have the ability to photo-cleave DNAs by generating reactive oxygen species. Reconstituted chromatin was assembled from large circular DNA (106 kbp) with core histone proteins. We also investigated the effect of vitamin C (ascorbic acid) on preventing photo-induced double-strand breaks in a quantitative manner. We found that DNA is protected against double-strand breaks by the addition of ascorbic acid, and this protective effect is dose dependent. The effective kinetic constant of the breakage reaction in the presence of 5 mM ascorbic acid is 20 times lower than that in the absence of ascorbic acid. This protective effect of ascorbic acid in reconstituted chromatin is discussed in relation to the highly compacted polynucleosomal structure. The results highlight the fact that single-molecule observation is a useful tool for studying double-strand breaks in giant DNA and chromatin.
Collapse
Affiliation(s)
- Yuko Yoshikawa
- Department of Food and Nutrition, Nagoya Bunri College, Nagoya 451-0077, Japan.
| | | | | | | | | | | |
Collapse
|
19
|
SUZUTO M, OHNISHI H, HIRAKAWA Y, MASUJIMA T. Manipulation of a Single DNA Molecule under the Pin-Fiber Video Scope. BUNSEKI KAGAKU 2005. [DOI: 10.2116/bunsekikagaku.54.455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Masashi SUZUTO
- Graduate School of Biomedical Sciences, Hiroshima University
| | - Hitoshi OHNISHI
- Graduate School of Biomedical Sciences, Hiroshima University
| | | | | |
Collapse
|