Increased PINK1 Confers a Neuroprotective Role After Glutamate Excitotoxicity in Neuronal Cells

Abstract Background: Ischemic insults often leads to mitochondrial dysfunction and neuronal injury. The neuronal damage induced by ischemia can be partly attributed to glutamate excitotoxicity. Previous studies have indicated that PINK1 plays a neuroprotective role against ischemic brain injury via regulating mitochondrial integrity and function. However, there are few reports elucidating the expression changes and effect of PINK1 on neuronal survival in glutamate excitotoxicity model.Methods: We utilized HT22 cells and primary cortical neurons to establish glutamate excitotoxicity neuronal model. Cell Counting Kit-8 was used to investigate the effects of different concentrations of glutamate on neuronal activity; RT-PCR assay was used to investigate PINK1 transcription level following glutamate excitotoxicity; Western-blot and immunofluorescence assays were used to evaluate PINK1 translation level after glutamate injury. Moreover, we established HT22 cell stable transformants by lentiviral transfection to determine the role of PINK1 on neuronal damages in glutamate excitotoxicity.Results: Different concentrations of glutamate inhibited the cell viability of HT22 line and primary cortical neurons. Following glutamate treatment at different times, the mRNA level, protein level and cellular fluorescence intensity of PINK1 firstly increased and then decreased. In addition, cells with low PINK1 expression could reinforce the inhibitory effect of glutamate on neuronal activity compared with normal cells, while high PINK1 expression showed a protective effect on neurons.Conclusion: PINK1 may play a neuroprotective role in glutamate induced neuronal excitotoxicity.