Dual effect of 17β-estradiol on NMDA-induced neuronal death: Involvement of metabotropic glutamate receptor 1

Simona Federica Spampinato, Sara Merlo, Gemma Molinaro, Giuseppe Battaglia, Valeria Bruno, Ferdinando Nicoletti, Maria Angela Sortino

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

Pretreatment with 10 nM 17β-estradiol (17βE2) or 100 μM of the metabotropic glutamate 1 receptor (mGlu1R) agonist, dihydroxyphenylglycine (DHPG), protected neurons against N-methyl-D-aspartate (NMDA) toxicity. This effect was sensitive to blockade of both estrogen receptors and mGlu1R by their respective antagonists. In contrast, 17βE2 and/or DHPG, added after a low-concentration NMDA pulse (45 μM), produced an opposite effect, i.e. an exacerbation of NMDA toxicity. Again this effect was prevented by both receptor antagonists. In support of an interaction of estrogen receptors and mGlu1R in mediating a neurotoxic response, exacerbation of NMDA toxicity by 17βE2 disappeared when cultures were treated with DHPG prior to NMDA challenge, and conversely, potentiation of NMDA induced cell death by DHPG was prevented by pretreatment with 17βE2. Addition of calpain III inhibitor (10μM), 2 h before NMDA, prevented the increased damage induced by the two agonists, an affect that can be secondary to cleavage of mGlu1R by calpain. Accordingly, NMDA stimulation reduced expression of the full-length (140 kDa) mGluR1, an effect partially reversed by calpain inhibitor. Finally, in the presence of NMDA, the ability of 17βE2 to stimulate phosphorylation of AKT and ERK was impaired. Pretreatment with calpain inhibitor prevented the reduction of phosphorylated ERK but had no significant effect on phosphorylated AKT. Accordingly, the inhibition of ERK signaling by U0126 (1 μM) counteracted the effect of calpain inhibition on 17βE2-induced exacerbation of NMDA toxicity. The present data confirm the dual role of estrogens in neurotoxicity/neuroprotection and highlight the role of the timing of exposure to estrogens.

Original languageEnglish (US)
Pages (from-to)5940-5948
Number of pages9
JournalEndocrinology
Volume153
Issue number12
DOIs
StatePublished - Dec 1 2012

ASJC Scopus subject areas

  • Endocrinology

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