Cell and Tissue Journal

Abstract Aim: the aim of this study was to examine the effect of glutathione peroxidase-1 (GPX-1) and shikonin on enhanced survival of dopaminergic neurons PC12 against parkinsonian toxicity.
Material and methods: in order to overexpress GPX-1 in PC12 neurons, recombinant lentiviruses carrying both GPX-1 and reporter GFP genes were generated and used to infect target cells. The survival rate of the transduced neurons in the presence or absence of shikonin was then quantified.
Results: following GFP gene expression observed under the fluorescent microscope, the overexpression of GPX-1 was determined using the RT-PCR analysis. Changes in cell survival against parkinsonian toxicity were examined in the presence of two factors: GPX-1 overexpression and shikonin treatment. The results indicated that both GPX-1 overexpression and shikonin treatment of the PC12 cells increased significantly cell survival against parkinsonian toxicity. Survival increased by 14% after GPX-1 overexpression and by 11% following shikonin treatment. More importantly, when the two factors were applied simultaneously (by shikonin treatment of GPX-1-overexpressing cells) they saved 83% of the neuronal cells that was up by 29%. This increase of survival rate was significant compared to the increase achieved by each factor alone.
 Conclusion: our data showed that GPX-1 gene overexpression and shikonin treatment not only individually increase PC12 cell survival against oxidative stress caused by the parkinonian toxin 6-OHDA, but also will function additively and/ or synergistically if they are applied together.