Epigenetic effects of antidepressants to neuroprotective genes in neuronal cultured cells

Antidepressants are widely used for treatment of depression. Imipramine, a typical antidepressant, is recently known to have an effect to restore the expression of brain-derived neurotrophic factor gene, which is decreased in depressed patients, by increasing histone acetylation. However, it is largely unknown whether other antidepressants have similar epigenetic effects to change gene expression. To address this question, we examined the effect of five antidepressants (imipramine, citalopram, duloxetine, amitriptyline, mirtazapine) on expression of genes associated with mental and neurodegenetative disorders. We found that 48-hour treatment with imipramine, citalopram, amitriptyline, mirtazapine, but not duloxetine, caused a large number of differentially expressed genes in primary neocortical neurons in mice. Focused on genes relating to neural protection and neuroplasticity, we discovered that amitriptyline not only enhanced the expression of atf3 and cox2 by increasing histone H3 Lys4 trimethylation (H3K4me3), but also protected neurons against oxygen-glucose deprivation and staurosporine-induced apoptosis. Our study will shed a new insight in understanding of the molecular and epigenetic mechanism of antidepressants.

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