Ionizing radiation altered the expression profiles and intracellular distribution of the circadian gene per1 in mouse brain neuronal cells

Circadian rhythms are highly conserved in virtually all organisms. They regulate numerous biological functions and keep them synchronized with alterations in the external environment. Environmental factors such as light, temperature and microgravity have been shown to affect circadian rhythms, but the impact of ionizing radiation (IR) on circadian rhythm is still elusive. Here, the transcription and translation of key circadian genes, such as per , clock , cry and bmal1 , were detected in mouse brain neurons after 2Gy X-ray or 2Gy carbon ion beam (CIB) irradiation and were compared with those in the unirradiated group. Moreover, the nuclear import of PER1 was detected by immunoblotting and immunofluorescence. The data showed that the expression phase of circadian genes was not significantly impacted by IR in either HT22 or BV2 cells, while the expression levels of per1 were markedly altered by both X-rays and carbon ion beams. Moreover, IR significantly promoted the nuclear import of PER1. Taken together, our findings suggest that IR, as an exogenous factor, disturbs per1 expression and promotes the nuclear import of PER1.