Protective effect of memantine against Doxorubicin toxicity in primary neuronal cell cultures: influence a
1Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland, jantas@if-pan.krakow.pl.
Abstract:
One of the serious unwanted effects of the anthracycline anticancer drug doxorubicin (Dox, adriamycin) is its neurotoxicity, which can be evoked by the activation of extracellular (FAS/CD95/Apo-1) pathway of apoptosis in cells. Since memantine, a clinically used N-methyl-D: -aspartic acid (NMDA) receptor antagonist, shows antiapoptotic action in several models of neuronal cell damage, in this study we evaluated the effect of memantine on the cell death induced by Dox in primary neuronal cell cultures. First, we investigated the effect of different concentrations of Dox (0.1-5 microM) on mouse neocortical, hippocampal, striatal, and cerebellar neurons on 7- and 12-day in vitro (DIV). The 7 DIV neuronal cell cultures were more prone to Dox-induced cell death than 12 DIV cultures. The cerebellar neurons were the most resistant to Dox-induced apoptosis in comparison to neuronal cell cultures derived from the forebrain. Memantine (0.1-2 microM) attenuated the Dox-evoked lactate dehydrogenase release in 7 DIV neuronal cell cultures with no significant effect on 12 DIV cultures. The ameliorating effect of memantine on Dox-mediated cell death was also confirmed by an increase in cell viability measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay. There was no effect of memantine on Dox-induced caspase-8 and -3 activity and Dox-evoked decrease in mitochondrial potential, although attenuation in the number of cells with apoptotic DNA fragmentation was observed. We also showed that the antiapoptotic effect of memantine in our model was NMDA receptor-independent, since two other antagonists of this receptor, MK-801 and AP-5, did not attenuate Dox-induced cell death. Furthermore, memantine did not influence the Dox-evoked increase in cytoplasmic Ca2+ level. The obtained data suggest developmental regulation of both, the Dox-mediated neurotoxicity and efficacy of memantine in alleviating the Dox-induced cell damage in neuronal cell cultures. Moreover, this neuroprotective effect of memantine seems not to be dependent on caspase-3 activity and on the antagonistic action on NMDA receptor.
Insights
Memantine reduces doxorubicin-induced neurotoxicity in developing neurons by decreasing apoptosis. This protective effect is independent of NMDA receptors and caspase-3 activity, suggesting developmental regulation of drug efficacy.
Area of Science:
- Neuroscience
- Pharmacology
- Cell Biology
Background:
- Doxorubicin (Dox) is an anthracycline anticancer drug with known neurotoxicity.
- This neurotoxicity is linked to the activation of extracellular apoptosis pathways.
- Memantine, an NMDA receptor antagonist, exhibits antiapoptotic properties in neuronal damage models.
Purpose of the Study:
- To evaluate the neuroprotective effect of memantine against doxorubicin-induced cell death in primary neuronal cultures.
- To investigate the developmental regulation of doxorubicin neurotoxicity and memantine's efficacy.
- To determine the mechanisms underlying memantine's neuroprotective action.
Main Methods:
- Primary mouse neocortical, hippocampal, striatal, and cerebellar neurons were cultured in vitro (7 and 12 days in vitro).
- Doxorubicin and memantine were applied at various concentrations to assess cell viability (LDH release, MTT assay) and apoptosis markers (DNA fragmentation, caspase activity, mitochondrial potential).
- NMDA receptor antagonists (MK-801, AP-5) and calcium imaging were used to explore memantine's mechanism of action.
Main Results:
- Younger (7 DIV) neuronal cultures were more susceptible to Dox-induced cell death than older (12 DIV) cultures, with cerebellar neurons showing higher resistance.
- Memantine significantly reduced Dox-evoked cell death and lactate dehydrogenase release in 7 DIV cultures, but not in 12 DIV cultures.
- Memantine's protective effect was independent of NMDA receptor antagonism, caspase-3 activity, and alterations in mitochondrial potential or cytoplasmic calcium levels, though it reduced DNA fragmentation.
Conclusions:
- Doxorubicin-induced neurotoxicity and memantine's efficacy in mitigating this damage are developmentally regulated in vitro.
- Memantine demonstrates neuroprotective effects against doxorubicin in developing neurons, independent of NMDA receptor blockade.
- The findings suggest novel therapeutic strategies for managing chemotherapy-induced neurotoxicity, highlighting the importance of developmental stage in drug response.
