A MAPK/c-Jun-mediated switch regulates the initial adaptive and cell death responses to mitochondrial damage in a neuronal cell model

Thomas A. Ryan, Katherine Roper, Jacquelyn Bond, Sandra M. Bell, Sean Sweeney, Ewan E. Morrison

Research output: Contribution to journalArticlepeer-review


Parkinson’s disease (PD) is defined by the progressive loss of dopaminergic
neurons. Mitochondrial dysfunction and oxidative stress are associated with PD
although it is not fully understood how neurons respond to these stresses. How
adaptive and apoptotic neuronal stress response pathways are regulated and the
thresholds at which they are activated remains ambiguous. Utilising SH-SY5Y
neuroblastoma cells, we show that MAPK/AP-1 pathways are critical in regulating the response to mitochondrial uncoupling. Here we found the AP-1 transcription factor cJun can act in either a pro- or anti-apoptotic manner, depending on the level ofstress. JNK-mediated cell death in differentiated cells only occurred once a threshold of stress was surpassed. We also identified a novel feedback loop between Parkin activity and the c-Jun response, suggesting defective mitophagy may initiate MAPK/c-Jun-mediated neuronal loss observed in PD. Our data supports the hypothesis that blocking cell death pathways upstream of c-Jun as a therapeutic target in PD may not be appropriate due to crossover of the pro- and anti-apoptotic responses. Boosting adaptive responses or targeting specific aspects of the neuronal death response may therefore represent more viable therapeutic strategies
Original languageEnglish
Pages (from-to)73-86
Number of pages14
JournalThe International Journal of Biochemistry & Cell Biology
Early online date17 Sept 2018
Publication statusPublished - Nov 2018

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