The Roles And Mechanisms Of TIGAR In Kainic-acid Induced Excitotoxicity In Primary Cortical Neurons

Aim: To study the roles and mechanisms of TIGAR in kainic acid-inducedexcitotoxicity in primary cortical neurons.Methods: The cultured cortical neurons were treated with KA (Kainic Acid) toestablish the excitotoxicity model in vitro. CCK-8was used to detect the survival rate ofcortical neurons. The protein levels of p53and TIGAR were determined by Western Blotanalysis. In the excitotoxixity model, the injury of neurons was detected by CCK-8afterknockdown of TIGAR. The protein levels of IκBα, p-IκBα and Caspase-3were assessedwith Western Blot. The effects of TIGAR on KA-induced activation of NF-κB,downregulation of mitochondrial membrane potential and upregulation of TUNEL-positiveneurons were analyzed by immunofluorescence analysis.Results: We have successfully established the model of excitotoxicity by KA in vitro.Exicitotoxic neuronal injury was induced after KA treatment as demonstrated by CCK-8and was significantly inhibited by knockdown of TIGAR. Western blot showed that theexpression of p53and TIGAR was markedly upregulated. And the upregulation of TIGARafter KA treatment was in a p53-dependent manner. The protein level of caspase-3, p-IκBαincreased after KA treatment, whereas the protein level of IκBα decreased after KAtreatment, and these changes can be inhibited by knockdown of TIGAR. Knockdown ofTIGAR could inhibit KA-induced activation of NF-κB and increase of the number ofTUNEL-positive cells. JC-1stainning showed the depolarization of mitochondrialmembrane potential after excitotoxic insult.Conclusions: These results showed that knockdown of TIGAR had neuroprotectiveeffects by inhibiting apoptosis, NF-κB nuclear translocation, IκBα degradation andphosphorylation.