N-methyl-d-aspartic acid receptor (NMDA) mediated excitotoxic destruction of striatal neurons is one of the models proposed for the pathogenesis of Huntington’s disease. Polyamines (putrescine, spermidine and spermine) may be involved in excitotoxicity by modulating NMDA receptors either in a negative or positive manner.Aims
In the framework of this work, we aimed to investigate the effects of polyamines on the mutant huntingtin mediated excitotoxicity.Methods
HEK293 cells, stably expressing mutant or normal htt were transiently transfected with NMDA receptor heterodimers (NR1/NR2A or NR1/NR2B) and then exposed to polyamines or polyamine biosynthesis inhibitors. Intracellular polyamine levels were determined by HPLC, cell viability was measured by MTT assay and the changes in protein expressions of huntingtin, inhibitor protein kappa B and ornithine decarboxylase were performed by western blotting.Results
It was found that exogenously applied Spd, Spm, α-difluoromethyl ornithine and cyclohexylamine, but not putrescine, cause an increase in the mutant huntingtin aggregates. On the other hand, polyamines and α-difluoromethyl ornithine increased the cell viability in mutant huntingtin expressing cells. Similar results were found for NR1/NR2A and NR1/NR2B expressing cells.Conclusions
The results showed that polyamines may contribute to HD pathology. However, future experiments are required to determine their contribution in detail.