Effect Of NT-3 On The Expression Of C-jun In The Rat Primary Cortical Neurons After Hypoxia In Vitro

[Objective] To investivate the effect of NT-3 on the expression of c-jun in the rat primary cortical neurons after hypoxia in vitro, and explore its protective function and mechanism to the cortical neurons.[Methods] The cortical neurons were cultured from rat cortices andidentified by immunocytochemistry and electronic microscrope. The hypoxic model of neurons were established. They were divided into 8 groups according to the NT-3 and hypoxia or not, which were A: conventional neurons(C); B: C.+1ng/ml NT-3; C: C. +30ng/ml NT-3; D: C. +100ng/ml NT-3; E: hypoxic neurons(-0); F: -0 +1ng/ml NT-3; G: -0 +30ng/ml NT-3; H: -0 +100ng/ml NT-3. The activities of the neurons were measured by MTT assay. The expression of c-jun mRNA were determined by semi-quantitative RT-PCR and c-jun proteins were tested by immunocytochemistry and Western-blot. [Results] MTT assays indicated that there were significant differences between the 0D values of B(0.28±0.02),C(0.39 ± 0.02),D(0.51 ± 0.02) and A(0.13±0.02) group, as they did between F(0.12±0.01),G(0.19±0.01), H(0.26±0.02) and E(0.09±0.02) group. Cultures of cortical neurons were also showed by immunocytochemistry to express high level of c-jun proteins in B,C,D,E,F,G,H, but there were only few c-jun positive neurons in A. RT-PCR indeed showed that higher expression of c-jun mRNA in B, C,D than those in A, as detected between F,G,H and E, indicating that NT-3 produced marked increases in the amount of c-jun mRNA in neurons. Similarly, the results showed by Western-blot were as the same as those by RT-PCR.[Conclusions] NT-3 can promote the survival and growth of the conventional cortical neurons in vitro, and it also produced protective...