The change of NFATc 4/3 signaling pathway in the rat hippocampus following whole brain irradiation

Objective: This study is to investigate the changes in the NFATc 4/3 signaling pathway in rat hippocampus alter whole brain radiation. Methods: A total of 120 one-month-old male Sprague-Dawley rats were randomly divided into four groups to receive whole brain radiation using 4-MeV electron beams with doses of 0(control), 2, 10, and 20 Gy, respectively, in a single fraction. At 6 hours, 12 hours, 1 day, 3 days, 1 week, and 2 weeks alter radiation, Western blot and real-time PCR were used to evaluate the changes in expression levels of. CaN, NFATc 4/3, p-NFATc 4/3, and GSK-3β. Results: There were no significant changes in the expression of NFATc 4/3 or p-NFATc 4/3 at 6 and 12 hours after whole brain radiation. At 1 day after radiation, compared with the control group, the expression of p-NFATc 4/3 in the radiation groups was significantly increased in a dose-dependent manner (2 Gy: P = 0.014; 10 Gy: P = 0.011; 20 Gy: P = 0.000); however, there was no significant difference in the expression of NFATc 4/3 between the radiation group and the control group. The expression of NFATc 4/3 was significantly decreased in the radiation groups than in the control group at day 3(2 Gy: P = 0.040; 10 Gy: P = 0.000; 20 Gy: P = 0.000), 1 week (2 Gy: P = 0.692; 10 Gy: P = 0.032; 20 Gy: P = 0.021), and 2 weeks (2 Gy: P = 0.001; 10 Gy: P = 0.000; 20 Gy: P = 0.000) after radiation, while there was no significant difference in the expression of p-NFATc 4/3 between any two groups. There were no time-or dose-dependent changes in expression of CaN or GSK-3β. Conclusions: Ionization radiation has an inhibitory effect on the NFATc 4/3 signaling pathway in rat hippocampus. Combined with our previous results, this study suggests that radiation-induced cognitive dysfunction is associated with the NFATc 4/3 signaling pathway. (authors)