Medical Radiology and Radiation Safety. 2024. Vol. 69. № 1


A.K. Chigasova1, 2, 3, M.V. Pustovalova1, 4, A.A. Osipov2, S.A. Korneva5,
P.S. Eremin6, E.I. Yashkina1, 2, M.A. Ignatov1, 2,Yu.A. Fedotov1, 2,
N.Yu. Vorobyeva1, 2, A.N. Osipov1, 2

Post-Radiation Changes in The Number of Phosphorylated H2ax
and Atm Protein Foci in Low Dose X-Ray Irradiated Human Mesenchymal Stem Cells


1 A.I. Burnazyan Federal Medical Biophysical Center, Moscow, Russia

2 N.N. Semenov Federal Research Center for Chemical Physics, Moscow, Russia

3 Institute of Biochemical Physics, Moscow, Russia

4 Moscow Institute of Physics and Technology, Moscow region, Dolgoprudny, Russia

5 M.V. Lomonosov Moscow State University, Moscow, Russia 

6 National Medical Research Center of Rehabilitation and Balneology, Moscow, Russia

Contact person: N.Yu. Vorobyeva, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.



Aim: To study the patterns of changes in the number of foci of phosphorylated DNA double-strand break repair proteins H2AX (γH2AX) and ATM (pATM) in cultured human mesenchymal stem cells (MSCs) 1‒48 hours after exposure to X-ray radiation at doses of 40, 80, 160 and 250 mGy. 

Material and methods: We used the primary culture of human MSCs, obtained from the collection of LLC “BioloT” (Russia). Cells were irradiated using a RUB RUST-M1 X-ray biological unit (Diagnostika-M LLC, Moscow, Russia) equipped with two X-ray emitters at a dose rate of 40 mGy/min (voltage of 100 kV, an anode current of 8 mA, and a 1.5 mm Al filter) and 4 °C temperature. To quantify the yield of γH2AX and pATM foci immunocytochemical staining was carried out with the use of γH2AX and pATM antibody respectively. Statistical analysis of the obtained data was carried out using the statistical software package Statistica 8.0 (StatSoft). To assess the significance of differences between samples, Student’s t-test was used.

Results: It was shown that the kinetics of changes in the number of γH2AX foci after irradiation at doses of 160 and 250 mGy and low (40‒80 mGy) doses are significantly different. In contrast to the significant (50‒60 %) decrease in the number of γH2AX foci observed
6 hours after irradiation at doses of 160 and 250 mGy, after irradiation at low doses, no significant decrease in γH2AX foci was observed at this time point. Analysis of the colocalization of γH2AX foci with pATM foci indicates that the mechanisms for maintaining a high number of γH2AX foci 24‒48 hours after low-dose irradiation are ATM independent. A hypothesis has been put forward to explain the phenomenon of maintaining the number of γH2AX foci 24‒48 hours after irradiation in low doses by replicative stress caused by stimulation of proliferation against the background of hyperproduction of free radicals, resulting in additional formation of DNA double-strand breaks and phosphorylation of H2AX by ATR kinase.


Keywords: mesenchymal stem cells, γH2AX, pATM, DNA double-strand breaks, X-ray radiation, low doses


For citation: Chigasova AK, Pustovalova MV, Osipov AA, Korneva SA, Eremin PS, Yashkina EI, Ignatov MA, Fedotov YuA, Vorobyeva NYu, Osipov AN. Post-Radiation Changes in The Number of Phosphorylated H2ax and Atm Protein Foci in Low Dose X-Ray Irradiated Human Mesenchymal Stem Cells. Medical Radiology and Radiation Safety. 2024;69(1):15–19. (In Russian). DOI:10.33266/1024-6177-2024-69-1-15-19



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Conflict of interest. The authors declare no conflict of interest.

Financing. The research was carried out with the support of the RNF (project No. 23-14-00078).

Contribution. Article was prepared with equal participation of the authors.

Article received: 20.10.2023. Accepted for publication: 27.11.2023.