Radiation Exposure of Peripheral Mononuclear Blood Cells Alters the Composition and Function of Secreted Extracellular Vesicles

Abstract

Normal tissue toxicity is a dose-limiting factor in radiation therapy. Therefore, a detailed understanding of the normal tissue response to radiation is necessary to predict the risk of normal tissue toxicity and to development strategies for tissue protection. One component of normal tissue that is continuously exposed during therapeutic irradiation is the circulating population of peripheral blood mononuclear cells (PBMC). PBMCs are highly sensitive to ionizing radiation (IR); however, little is known about how IR affects the PBMC response on a systemic level. It was the aim of this study to investigate whether IR was capable to induce changes in the composition and function of extracellular vesicles (EVs) secreted from PBMCs after radiation exposure to different doses. Therefore, whole blood samples from healthy donors were exposed to X-ray radiation in the clinically relevant doses of 0, 0.1, 2 or 6 Gy and PBMC-secreted EVs were isolated 72 h later. Proteome and miRNome analysis of EVs as well as functional studies were performed. Secreted EVs showed a dose-dependent increase in the number of significantly deregulated proteins and microRNAs. For both, proteome and microRNA data, principal component analysis showed a dose-dependent separation of control and exposed groups. Integrated pathway analysis of the radiation-regulated EV proteins and microRNAs consistently predicted an association of deregulated molecules with apoptosis, cell death and survival. Functional studies identified endothelial cells as an efficient EV recipient system, in which irradiation of recipient cells further increased the uptake. Furthermore an apoptosis suppressive effect of EVs from irradiated PBMCs in endothelial recipient cells was detected. In summary, this study demonstrates that IR modifies the communication between PBMCs and endothelial cells. EVs from irradiated PBMC donors were identified as transmitters of protective signals to irradiated endothelial cells. Thus, these data may lead to the discovery of biomarker candidates for radiation dosimetry and even more importantly, they suggest EVs as a novel systemic communication pathway between irradiated normal, non-cancer tissues.

DNA Damage Regulates Senescence-Associated Extracellular Vesicle Release via the Ceramide Pathway to Prevent Excessive Inflammatory Responses

“…Treatment with DXR increased the signs of the DNA damage response (DDR) in a dose-dependent manner, as judged by DNA damage foci (the phosphorylation of H2AX and the consensus target sequences of ATM/ATR) ( Figure 1A). Consistent with several previous reports [24,26,32,33], nanoparticle tracking analysis (NTA) revealed that an increase in small EV secretion was concomitant with the level of DNA damage ( Figure 1B). Since DNA damage is known to cause cellular senescence in normal cells, we investigated the molecular mechanism of small EV secretion, induced by DNA damage, using both young and senescent HDFs.…”

Proteomics of Non-human Primate Plasma after Partial-body Radiation with Minimal Bone Marrow Sparing

“…Two of them, CRP and SAA1, are fast reactants of acute phase response which were also proposed as candidate biomarkers for radiation injury in previous studies (Ossetrova and Blakely 2009;Bazan et al 2014;Nylund et al 2014;Ossetrova et al 2014b;Widlak et al 2015;Byrum et al 2017;Blakely et al 2018;Ossetrova et al 2018;Sproull et al 2019). Nine out of the 49 additional protein have been noted in previous radiation biomarker reports including C9, CP, FGA, ITIH3, HP, HPX, LRG1, SERPINA3, and SOD1 (Magic et al 1995;Hayashi et al 2003;Hayashi et al 2005;Ossetrova and Blakely 2009;Bazan et al 2014;Nylund et al 2014;Ossetrova et al 2014b;Widlak et al 2015;Byrum et al 2017;Blakely et al 2018;Ossetrova et al 2018;Liu et al 2019;Ouerhani et al 2019;Sproull et al 2019;Moertl et al 2020;Sun et al 2020). Bone marrow derived protein Flt-3L that has been proposed as a biomarker was not detected in our data (Ossetrova et al 2014b).…”

Ionizing Radiation Protein Biomarkers in Normal Tissue and Their Correlation to Radiosensitivity: A Systematic Review

“…Amongst the studies, which investigated proteins other than repair foci, 15 studies were included: five cohort studies (Braicu et al, 2014 [ 40 ], Rodruiguez-Gil et al, 2014 [ 41 ], Skiöld et al, 2015 [ 42 ], Yu et al, 2018 [ 43 ], and Lacombe et al, 2019 [ 44 ]) and 10 studies on model systems (Cao et al, 2011 [ 45 ], Park et al, 2012 [ 46 ], Fekete et al, 2015 [ 47 ], Minafra et al, 2015 [ 37 ], Nishad and Ghosh, 2015 [ 48 ], Shimura et al, 2015 [ 49 ], Yim et al, 2017 [ 50 ], Miyake et al, 2019 [ 38 ], Nguyen et al, 2019 [ 39 ], Moertl at al., 2020 [ 51 ]). In total, 5 of these 10 studies were conducted with peripheral blood mononuclear cells (PBMCs) (Yu et al, 2018, Nguyen et al, 2019, Lacombe et al, 2019, Skiöld et al, 2015, and Nishad and Ghosh, 2015), and one with PBMCs-derived extracellular vesicles (Moertl et al, 2020).…”