Up-regulation Of NFATc4 Involves In Neuronal Apoptosis Following Intracerebral Hemorrhage

Objective The study was designed to investigate the molecular nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 4(NFATc4) by establishing intracerebral hemorrhage(ICH) model both in vivo and in vitro. We learnt the expression and distribution variations of NFATc4 following ICH in the corresponding case, explored the role of NFATc4 playing in cell apoptosis and further sought the underlying mechanisms.Methods The ICH model was established in vivo by dripping autologous whole blood drawed from the cut tail into the rats’ right caudate putamen, using stereotaxic apparatus. The rats suffering from ICH were then assessed and analysed by the behavioral testing, including forelimb placing test and corner turn test, showing functional damage at different levels. The expression changes of NFATc4 and corresponding moleculars like Fas L surrouding the hematoma were all detected by Western blot. Again, the expression and distribution of NFATc4 was investigated by performing immunohistochemical. Next, the co-localization of NFATc4 with neuron was found using immunofluorenscence. Furthermore, we explored the relationship between NFATc4 and cell apoptosis both in vivo and in vitro, by combing the above methods, detecting the expression and distribution of the extrinsic pathway downstream. All the data of the two groups was analyzed statistically with Stata 7.0 statistics software.Results Here, we explored the NFATc4’s roles during the pathophysiological processes of ICH. An ICH rat model was built and then evaluated according to behavioral testing. Using Western blot and immunohistochemistry, significant up-regulation of NFATc4 was detected in neurons in brain areas surrounding the hematoma following ICH; immunofluorescence indicated intensive NFATc4 staining was only observed in neurons following ICH, and exhibited the translocation of NFATc4 from cytoplasm by following nuclear and cytoplasmic extraction protocol. Increasing NFATc4 expression was found to be accompanied by the up-regulation of Fas ligand(Fas L), active caspase-8, and active caspase-3, respectively. Besides, NFATc4 co-localized with active caspase-3 in neurons, indicating its role in neuronal apoptosis following ICH. We built hemin-induced apoptosis model in PC12 cells to authenticate our hypothesis, and we validated the results in vivo. Our study in vitro, using NFATc4 RNA interference in PC12 cells, further confirmed that NFATc4 might exert its pro-apoptotic function in neuronal apoptosis through extrinsic pathway. Thus, NFATc4 may play a role in promoting the brain secondary damage following ICH, which provides the therapeutic target in future.Conclusions On the whole, the present research for the first time detected the expression and distribution variations of NFATc4 surrounding the hematoma; and all the data certificated the involvement of NFATc4 in neuronal apoptosis following ICH. Nevertheless, further studies remains to be done to seek the underlying cellular and molecular mechanisms, and provide therapeutic potentials for ICH clinically.