Abstract
Background: Little is known about the immediate effects of whole-brain γ-irradiation. The authors hypothesize that Egr1 as an immediate early gene and microglia both participate in early reactions. Material and Methods: Both, expression of Egr1 and cellular distribution were studied in a temporal sequence in different brain regions of rats subjected to irradiation with 10 Gy. Brain tissue was examined using immunohistochemistry, real-time RT-PCR (reverse transcription-polymerase chain reaction), and Western blotting. Results: Astroglia and oligodendroglia showed increased Egr1 immunoreactivity within the first hours following irradiation. This was accompanied by a strong peak in CD68 immunoreactivity histologically attributable to activated microglia. A high constitutive expression of Egr1 protein in the nuclei of activated neurons was reduced following irradiation and RT-PCR demonstrated significantly reduced levels of egr1-lv as a neuronal activity-related mRNA variant. Conclusion: The induction of Egr1 in glial cells, as well as the activation of microglia take place earlier than histological changes reported so far. The authors revealed a temporal sequence of reactions that point toward the initiation of an immediate inflammatory response including reduced neuronal activity.
| Original language | English |
|---|---|
| Journal | Strahlentherapie und Onkologie |
| Volume | 183 |
| Issue number | 5 |
| Pages (from-to) | 248-255 |
| Number of pages | 8 |
| ISSN | 0179-7158 |
| DOIs | |
| Publication status | Published - 05.2007 |
