// <![CDATA[ $('.header-date').hide();$('#titleAuthors').hide();$('#abstractHeader').hide(); // ]]> Andreyan N. Osipov1, 2, 3, 4, Margarita Pustovalova1, 2, Anna Grekhova1, 5, Petr Eremin1, Natalia Vorobyova1, 3, Andrey Pulin1, Alex Zhavoronkov4, 6, 7, Sergey Roumiantsev3, 4, 8, Dmitry Y. Klokov9, Ilya Eremin1 1State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency (SRC-FMBC), Moscow, Russia 2Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia 3Dmitry Rogachev Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia 4Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia 5Emanuel Institute for Biochemical Physics, Russian Academy of Sciences, Moscow, Russia 6Insilico Medicine, Inc, ETC, Johns Hopkins University, Baltimore, Maryland, USA 7The Biogerontology Research Foundation, BGRF, London, UK 8N.I. Pirogov Russian National Research Medical University, Moscow, Russia 9Canadian Nuclear Laboratories, Chalk River, Ontario, Canada Correspondence to: Andreyan N. Osipov, e-mail: andreyan.osipov@gmail.com Keywords: mesenchymal stem cells, DNA double-strand breaks, DNA repair, X-rays, low doses Received: April 08, 2015 Accepted: July 10, 2015 Published: July 23, 2015

H2AX, 53BP1 and Rad51 protein foci changes in mesenchymal stem cells during prolonged X-ray irradiation γH2AX, 53BP1 and Rad51 protein foci changes in mesenchymal stem cells during prolonged X-ray irradiation

// <![CDATA[ $('.header-date').hide();$('#titleAuthors').hide();$('#abstractHeader').hide(); // ]]> Andreyan N. Osipov1, 2, 3, 4, Anna Grekhova1, 5, Margarita Pustovalova1, 2, Ivan V. Ozerov1, Petr Eremin1, Natalia Vorobyeva1, 3, Natalia Lazareva1, Andrey Pulin1, Alex Zhavoronkov4, 6, 7, Sergey Roumiantsev3, 4, 8, Dmitry Klokov9, Ilya Eremin1 1State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency (SRC-FMBC), Moscow 123098, Russia 2Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow 119991, Russia 3Dmitry Rogachev Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow 117997, Russia 4Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia 5Emanuel Institute for Biochemical Physics, Russian Academy of Sciences, Moscow 119991, Russia 6Insilico Medicine, Inc, ETC, Johns Hopkins University, Baltimore, MD 21218, USA 7The Biogerontology Research Foundation, BGRF, London W1J 5NE, UK 8N.I. Pirogov Russian National Research Medical University, Moscow 117997, Russia 9Canadian Nuclear Laboratories, Chalk River, ON K0J1P0, Canada Correspondence to: Andreyan N. Osipov, e-mail: andreyan.osipov@gmail.com Keywords: DNA DSB repair, homologous recombination, human fibroblasts, X-rays, continuous irradiation Received: April 08, 2015 Accepted: July 31, 2015 Published: August 13, 2015

The aim of this study was to verify the applicability of high-concentration collagen-based bioink with MSC (ADSC) and decellularized ECM granules for the formation of cartilage tissue de novo after subcutaneous implantation of the scaffolds in rats. The printability of the bioink (4% collagen, 2.5% decellularized ECM granules, derived via 280 μm sieve) was shown. Three collagen-based compositions were studied: (1) with ECM; (2) with MSC; (3) with ECM and MSC. It has been established that decellularized ECM granules are able to stimulate chondrogenesis both in cell-free and MSC-laden scaffolds. Undesirable effects have been identified: bone formation as well as cartilage formation outside of the scaffold area. The key perspectives and limitations of ECM granules (powder) application have been discussed.

Ionizing radiation (IR) is used for patients diagnosed with unresectable non-small cell lung cancer (NSCLC). However, radiotherapy remains largely palliative due to the survival of specific cell subpopulations. In the present study, the sublines of NSCLC cells, A549IR (p53wt) and H1299IR (p53null) survived multifraction X-ray radiation exposure (MFR) at a total dose of 60 Gy were investigated three weeks after the MFR course. We compared radiosensitivity (colony formation), expression of epithelial-mesenchymal transition (EMT) markers, migration activity, autophagy, and HR-dependent DNA double-strand break (DSB) repair in the bulk and entire CD44high/CD166high CSC-like populations of both parental and MFR survived NSCLC cells. We demonstrated that the p53 status affected: the pattern of expression of N-cadherin, E-cadherin, Vimentin, witnessing the appearance of EMT-like phenotype of MFR-surviving sublines; 1D confined migratory behavior (wound healing); the capability of an irradiated cell to continue to divide and form a colony of NSCLC cells before and after MFR; influencing the CD44/CD166 expression level in MFR-surviving NSCLC cells after additional single irradiation. Our data further emphasize the impact of p53 status on the decay of γH2AX foci and the associated efficacy of the DSB repair in NSCLC cells survived after MFR. We revealed that Rad51 protein might play a principal role in MFR-surviving of p53 null NSCLC cells promoting DNA DSB repair by homologous recombination (HR) pathway. The proportion of Rad51 + cells elevated in CD44high/CD166high population in MFR-surviving p53wt and p53null sublines and their parental cells. The p53wt ensures DNA-PK-mediated DSB repair for both parental and MFR-surviving cells irrespectively of a subsequent additional single irradiation. Whereas in the absence of p53, a dose-dependent increase of DNA-PK-mediated non-homologous end joining (NHEJ) occurred as an early post-irradiation response is more intensive in the CSC-like population MFR-surviving H1299IR, compared to their parental H1299 cells. Our study strictly observed a significantly higher content of LC3 + cells in the CD44high/CD166high populations of p53wt MFR-surviving cells, which enriched the CSC-like cells in contrast to their p53null counterparts. The additional 2 Gy and 5 Gy X-ray exposure leads to the dose-dependent increase in the proportion of LC3 + cells in CD44high/CD166high population of both parental p53wt and p53null, but not MFR-surviving NSCLC sublines. Our data indicated that autophagy is not necessarily associated with CSC-like cells’ radiosensitivity, emphasizing that careful assessment of other milestone processes (such as senescence and autophagy-p53-Zeb1 axis) of primary radiation responses may provide new potential targets modulated for therapeutic benefit through radiosensitizing cancer cells while rescuing normal tissue. Our findings also shed light on the intricate crosstalk between autophagy and the p53-related EMT, by which MFR-surviving cells might obtain an invasive phenotype and metastatic potential.

Laser therapy as a physiotherapeutic method has been successfully used for a long time in the treatment of various pathologies, but the action mechanisms of low level laser therapy (LLLT) remain understudied. Objective. To perform the analysis of published results of LLLT investigations, to describe the physical principles of photobiomodulation, its action mechanisms on various cells and tissues, therapeutic intervention and efficiency of the technique. Material and methods. The search of articles was done for the period from 2014 to 2022. The preference was given to the articles for the last 5 years in the PubMed database depending on keywords: low level laser therapy, photobiomodulation, exosomes, monocytes, macrophages. Results and discussion. This article represents the current conceptions about the action mechanisms and reproduced effects of low level laser therapy, the photobiomodulation influence on the inflammation and reparative processes in human body by intervention on cells and their signal pathways. The discussion of research results and probable causes of conflicting data are performed, as well as the efficacy assessment of laser irradiation in different conditions and diseases is made. Conclusion. Laser therapy has certain variety of advantages, among which: non-invasiveness and availability, long-term service of equipment, stable intensity of light radiation and the ability to use in various wavelength ranges. The technique efficacy was proven for a large number of diseases. However, for the successful application of photobiomodulation in clinical practice in current evidence-based medicine, additional investigations are necessary to determine the best dosimetric radiation parameters, as well as further study of action mechanisms on various human cells and tissues.