Medical Radiology and Radiation Safety. 2025. Vol. 70. № 2
DOI:10.33266/1024-6177-2025-70-2-16-22
S.A. Abdullaev1, 2, 3, D.V. Fomina1, 3, V.O. Menukhov1, 2, M.V. Dushenko1,
A.V. Tochilenko4, T.P. Kalinin5, E.V. Evdokimovskii2
Changes in the Copy Number and Gene Expression of mtDNA
in Various Tissues of Mice Exposed to Local Brain Irradiation
1 N.N. Semenov Federal Research Center for Chemical Physics, Moscow, Russia
2 Institute of Theoretical and Experimental Biophysics, Pushchino, Russia
3 A.I. Burnazyan Federal Medical Biophysical Center, Moscow, Russia
4 National Research Nuclear University MEPhI, Moscow, Russia
5 N.I. Pirogov Russian National Research Medical University, Moscow, Russia
Contact person: S.A. Abdullaev, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
ABSTRACT
Purpose: To determine changes in the copy number and gene expression of mtDNA in various tissues of mice subjected to local irradiation of the brain.
Material and methods: Male Balb/c mice aged 2 months were used. Only the head of the mouse was exposed to X-ray irradiation at a dose of 5 Gy (power 2.5 Gy/min). After removal from the animals, the tissues were homogenized on ice, after which the homogenate mass was divided into two parts to isolate nucleic acids. Liquid blood was collected separately, after which nucleated blood cells were separated into granulocyte and monocyte fractions by differential centrifugation by Diacoll density gradient. The total number of mtDNA copies and gene expression were assessed using real-time PCR.
Results: It was shown that in nucleated blood cells, after irradiation, the relative number of transcripts of the mitochondrial gene ATP6 increases. In granulocytes, this effect is much more pronounced than in monocytes. At the same time, the amount of mitochondrial DNA in nucleated blood cells decreases relative to the control level by 2–3 times. In the brain exposed to irradiation, an increase in the relative amount of mtDNA transcripts by about 3 times is also observed, compared to the control. In organs not exposed to irradiation (heart, liver, spleen), the same effect is observed as in the brain, namely, an increase in the relative amount of mtDNA transcripts. The number of copies of mtDNA itself in brain cells, after a sharp increase a day after irradiation, sharply decreases and remains so until the end of the experiment, 30 days later. In liver and heart cells, the opposite process occurs, namely, a significant increase in the number of mtDNA copies, with a maximum at 14–21 days from the moment of irradiation.
Conclusion: Thus, the obtained results allow us to say that the observed changes are due to the occurrence of the “bystander effect” that arose after local irradiation of the brain with X-ray radiation at a dose of 5 Gy.
Keywords: mtDNA, bystander effect, oxidative stress, X-ray exposure, brain, mice
For citation: Abdullaev SA, Fomina DV, Menukhov VO, Dushenko MV, Tochilenko AV, Kalinin TP, Evdokimovskii EV. Changes in the Copy Number and Gene Expression of mtdna in Various Tissues of Mice Exposed to Local Brain Irradiation. Medical Radiology and Radiation Safety. 2025;70(2):16–22. (In Russian). DOI:10.33266/1024-6177-2025-70-2-16-22
References
1. Pant G.S., Kamada N. Chromosome Aberrations in Normal Leukocytes Induced by the Plasma of Exposed Individuals. J Med Sci. 1977;26;2-3:149-154.
2. Hollowell J.G., Littlefeld L.G. Chromosome Damage Induced by Plasma of X-Rayed Patients: an Indirect Effect of X-Ray. Proc Soc Exp Biol Med. 1968;129;1:240-244. doi: 10.3181/00379727-129-33295.
3. Littlefeld L.G., Hollowell Jr J.G., Pool Jr W.H. Chromosomal Aberrations Induced by Plasma from Irradiated Patients: an Indirect Effect of X Radiation. Further Observations and Studies of a Control Population. Radiology. 1969;93;4:879-886. doi: 10.1148/93.4.879.
4. Marozik P., Mothersill C., Seymour C.B., Mosse I., Melnov S. Bystander Effects Induced by Serum from Survivors of the Chernobyl Accident. Exp Hematol. 2007;35;4-1:55-63. doi: 10.1016/j.exphem.2007.01.029.
5 Emerit I., Quastel M., Goldsmith J., Merkin L., Levy A., Cernjavski L., et al. Clastogenic Factors in the Plasma of Children Exposed at Chernobyl. Mutat Res. 1997;373;1:47-54. doi: 10.1016/s0027-5107(96)00187-x.
6. Gemignani F., Ballardin M., Maggiani F., Rossi A.M., Antonelli A., Barale R. Chromosome Aberrations in Lymphocytes and Clastogenic Factors in Plasma Detected in Belarus Children 10 Years after Chernobyl Accident. Mutat Res. 1999;446;2:245-253. doi: 10.1016/s1383-5718(99)00194-1.
7. Nagasawa H., Little J.B. Induction of Sister Chromatid Exchanges by Extremely Low Doses of Alpha-Particles. Cancer Res. 1992;52;22:6394-6.
8. Ghosh G. Radiation-Induced Bystander Effect and Its Possible Countermeasures. J Cell Signal. 2023;4;1:13-20. doi: 10.33696/Signaling.4.086.
9. Gilbert A., Payet V., Bernay B., Chartier-Garcia E., Testard I., Candéias S.M., Chevalier F. Label-Free Direct Mass Spectrometry Analysis of the Bystander Effects Induced in Chondrocytes by Chondrosarcoma Cells Irradiated with X-rays and Carbon Ions. Front Biosci (Landmark Ed). 2022;27;9:277. doi: 10.31083/j.fbl2709277.
10. Vasilyeva I.N. Low-Molecular-Weight DNA in Blood Plasma as an Index of the Influence of Ionizing Radiation. Ann N Y Acad Sci. 2001;945:221-8. doi: 10.1111/j.1749-6632.2001.tb03889.x.
11. Cooke M.S., Evans M.D., Dizdaroglu M., Lunec J. Oxidative DNA Damage: Mechanisms, Mutation, and Disease. FASEB J. 2003;17;10:1195-1214. doi: 10.1096/fj.02-0752rev.
12. Ermakov A.V., Konkova M.S., Kostyuk S.V., Smirnova T.D., Malinovskaya E.M., Efremova L.V., Veiko N.N. An Extracellular DNA Mediated Bystander Effect Produced from Low Dose Irradiated Endothelial Cells. Mutat Res. 2011;712;1-2:1-10. doi: 10.1016/j.mrfmmm.2011.03.002.
13. Randhawa A.K., Hawn T.R. Toll-Like Receptors: their Roles in Bacterial Recognition and Respiratory Infections. Expert Rev Anti Infect Ther. 2008;6;4:479-495. doi: 10.1586/14787210.6.4.479.
14. Taanman J.W. The Mitochondrial Genome: Structure, Transcription, Translation and Replication. Biochim Biophys Acta. 1999;1410;2:103-123. doi: 10.1016/s0005-2728(98)00161-3.
15. Zhang Q., Raoof M., Chen Y., Sumi Y., Sursal T., Junger W., et al. Circulating Mitochondrial DAMPs Cause Inflammatory Responses to Injury. Nature. 2010;464;7285:104-107. doi: 10.1038/nature08780.
16. Liu Q., Wu J., Zhang X., Li X., Wu X., Zhao Y., Ren J. Circulating Mitochondrial DNA-Triggered Autophagy Dysfunction Via STING Underlies Sepsis-Related Acute Lung Injury. Cell Death Dis. 2021;12;7:673. doi: 10.1038/s41419-021-03961-9.
17. Mothersill C., Seymour C. Radiation-Induced Bystander Effects: Past History and Future Directions. Radiat Res. 2001;155;6:759-67. doi: 10.1667/0033-7587(2001)155[0759:ribeph]2.0.co;2.
18. Nikjoo H., Khvostunov I.K. Biophysical Model of the Radiation-Induced Bystander Effect. Int J Radiat Biol. 2003;79;1:43-52.
19. Nikjoo H., Khvostunov I.K. A Theoretical Approach to the Role and Critical Issues Associated with Bystander Effect in Risk Estimation. Hum Exp Toxicol. 2004;23;2:81-6. doi: 10.1191/0960327104ht422oa.
20. Azzam E.I., De Toledo S.M., Spitz D.R., Little J.B. Oxidative Metabolism Modulates Signal Transduction and Micronucleus Formation in Bystander Cells from Alpha-Particle-Irradiated Normal Human Fibroblast Cultures. Cancer Res. 2002;62;19:5436-42.
21. Matsumoto H., Hamada N., Takahashi A., Kobayashi Y., Ohnishi T. Vanguards of Paradigm Shift in Radiation Biology: Radiation-Induced Adaptive and Bystander Responses. J Radiat Res. 2007;48;2:97-106. doi: 10.1269/jrr.06090.
22. Matsumoto H., Tomita M., Otsuka K., Hatashita M., Hamada N. Nitric Oxide is a Key Molecule Serving as a Bridge between Radiation-Induced Bystander and Adaptive Responses. Curr Mol Pharmacol. 2011;4;2:126-34. doi: 10.2174/1874467211104020126.
23. Morgan W.F. Communicating Non-Targeted Effects of Ionizing Radiation to Achieve Adaptive Homeostasis in Tissues. Curr Mol Pharmacol. 2011;4;2:135-40.
24. Ermakov A.V., Kon’kova M.S., Kostyuk S.V., Ershova E.S., Egolina N.A., Veĭko N.N. Extracellular DNA Fragments from Culture Medium of Low-Dose Irradiated Human Lymphocyte Trigger Instigating of the Oxidative Stress and the Adaptive Response in Non-Irradiated Bystander Lymphocytes. Radiats Biol Radioecol. 2008;48;5:553-64.
25. Kostyuk S.V., Ermakov A.V., Alekseeva A.Yu., Smirnova T.D., Glebova K.V., Efremova L.V., Baranova A., Veiko N.N. Role of Extracellular DNA Oxidative Modification in Radiation Induced Bystander Effects in Human Endotheliocytes. Mutat Res. 2012;729;1-2:52-60. doi: 10.1016/j.mrfmmm.2011.09.005.
26. Wu Z., Oeck S., West A.P., Mangalhara K.C., Sainz A.G., Newman L.E., et al. Mitochondrial DNA Stress Signalling Protects the Nuclear Genome. Nat Metab. 2019;1;12:1209-1218. doi: 10.1038/s42255-019-0150-8.
PDF (RUS) Full-text article (in Russian)
Conflict of interest. The authors declare no conflict of interest.
Financing. The work was supported by the Russian Science Foundation (project No. 24-24-00446).
Contribution. Article was prepared with equal participation of the authors.
Article received: 20.12.2024. Accepted for publication: 25.01.2025.