The Atypical Antidepressant Tianeptine Confers Neuroprotection against Oxygen-Glucose Deprivation

Proregenerative and neuroprotective effects of antidepressants are an important topic of inquiry in neuropsychiatric research. Oxygen-glucose deprivation (OGD) mimics key aspects of ischemic injuryin vitro. Here, we studied the effects of 24-h pretreatment with serotonin (5-HT), citalopram (CIT), fluoxetine (FLU), and tianeptine (TIA) on primary mouse cortical neurons subjected to transient OGD. 5-HT (50 µM) statistically significantly enhanced neuron viability as measured by MTT assay and reduced cell death and LDH release. CIT (10 µM) and FLU (1 µM) did not increase the effects of 5-HT and neither antidepressant conferred neuroprotection in the absence of supplemental 5-HT in serum-free cell culture medium. By contrast, pre-treatment with TIA (10 µM) resulted in robust neuroprotection, even in the absence of 5-HT. Furthermore, TIA inhibited mRNA transcription of candidate genes related to cell death and hypoxia and attenuated lipid peroxidation, a hallmark of neuronal injury. Finally, deep RNA sequencing of primary neurons subjected to OGDdemonstrated that OGD induces many pathways relating to cell survival, the inflammation-immune response, synaptic dysregulation and apoptosis, andthatTIA pretreatment counteracted theseeffects of OGD. In conclusion, this study highlights the comparative strength of the 5-HT independent neuroprotective effects of TIA and identifies the molecular pathways involved. Overall design: Primary neuronal cultures obtained from the cortex of embryonic mice at embryonic day 15 were pretreated with 10 µM TIA at 8 DIV and they were exposed to in vitro ischemic damage via 3 h-OGD at 9 DIV. Total RNA from each condition (CONTROL-VEH, CONTROL-TIA, OGD-VEH and OGD-TIA) was extracted 6 hours after OGD. 4 replicates for each condition was used for RNA-seq.