Ionizing Radiation Effects In Vitro Study; Using The Rat Whole Embryo Culture Model

Background: Ionizing radiation poses a threat to the early embryo possibly leading to prenatal death, growth retardation, organ malformation, or mental retardation. It is important, assessment of any adverse effects of radiation upon the embryo. This study aimed to evaluate the outcomes of embryos irradiated with 1Gy doses in vitro and investigate hematopoiesis in the yolk sac of the irradiated embryos. Materials and methods: In the study, the experimental group of rats was be exposed to total body ionizing radiation on days 8.5th of gestation. All embryos in the control and radiation group cultured from gestation day 9.5 to 11.5 were alive at the end of the culture period. After 48 hours culture period, the embryos from each group were harvested and analyzed morphologically. Histological evaluation of the vWF+ cell number was performed in vivo. Results: The results showed that the embryonic growth and development during organogenesis decreased in the radiation exposed embryos when compared to control embryos. Additionally, the immunofluorescent examination showed that the vWF+ cell number reduced in the yolk sac of embryos exposed to ionizing radiation. Conclusion: Consequently, these findings support the conclusion that 1 Gy ionizing irradiation may increase prenatal death, intrauterine growth restriction on embryonic development when ionizing irradiation decreases the vWF+ cell number in the yolk sac compared to control embryos. This research related to radiation was the first study using the in vitro embryo culture technique; thus, future studies that will be performed by using different doses of radiation will contribute to the literature.

X-ray Irradiation activates immune response in human T-lymphocytes by eliciting a Ca2+ signaling cascade

Radiation therapy is efficiently employed for eliminating cancer cells and reducing tumor growth. To further improving its therapeutic application it is mandatory to unravel the molecular effects of ionizing irradiation and to understand whether they support or counteract tumor therapy. Here we examine the impact of X-ray irradiation on immune activation of human T cells with single doses typically employed in tumor therapy. We discover that exposing cells to radiation triggers in a population of leukemic Jurkat T cells and in peripheral blood mononuclear cells (PBMCs) a canonical Ca2+ signaling cascade, which elicits immune activation of these cells. An early step in the signaling cascade is the initiation of sustained oscillations of the cytosolic Ca2+ concentration, an event mediated by store operated Ca2+ entry (SOCE) via an X-ray induced clustering of the Calcium Release-Activated Calcium Modulator 1 with the stromal interaction molecule 1 (Oari1/STIM1). A functional consequence of the Ca2+ signaling cascade is the translocation of the transcription factor nuclear factor of activated T cells (NFAT) from the cytosol into the nucleus where it elicits the expression of genes required for immune activation. These data imply that a direct activation of blood immune cells by ionizing irradiation has an impact on toxicity and therapeutic effects of radiation therapy.