17β-Estradiol-Mediated Neuroprotection and ERK Activation Require a Pertussis Toxin-Sensitive Mechanism Involving GRK2 and β-Arrestin-1
journal contributionposted on 2023-05-19, 13:13 authored by Dominguez, R, Hu, E, Zhou, M, Baudry, M
17-β-Estradiol (E2) is a steroid hormone involved in numerous bodily functions, including several brain functions. In particular, E2 is neuroprotective against excitotoxicity and other forms of brain injuries, a property that requires the extracellular signal-regulated kinase (ERK) pathway and possibly that of other signaling molecules. The mechanism and identity of the receptor(s) involved remain unclear, although it has been suggested that E2 receptor α (ERα) and G proteins are involved. We, therefore, investigated whether E2-mediated neuroprotection and ERK activation were linked to pertussis toxin (PTX)-sensitive G-protein-coupled effector systems. Biochemical and image analysis of organotypic hippocampal slices and cortical neuronal cultures showed that E2-mediated neuroprotection as well as E2-induced ERK activation were sensitive to PTX. The sensitivity to PTX suggested a possible role of G-protein- and β-arrestin-mediated mechanisms. Western immunoblots from E2-treated cortical neuronal cultures revealed an increase in phosphorylation of both G-protein-coupled receptor-kinase 2 and β-arrestin-1, a G-proteincoupled receptor adaptor protein. Transfection of neurons with β-arrestin-1 small interfering RNA prevented E2-induced ERK activation. Coimmunoprecipitation experiments indicated that E2 increased the recruitment of β-arrestin-1 and c-Src to ERα. These findings suggested that ERα is regulated by a mechanism associated with receptor desensitization and downregulation. In support of this idea, we found that E2 treatment of cortical synaptoneurosomes resulted in internalization of ERα, whereas treatment of cortical neurons with the ER agonists E-6-BSA-FITC [β-estradiol-6- (O-carboxymethyl)oxime-bovine serum albumin conjugated with fluorescein isothiocyanate] and E-6-biotin [1,3,5(10)-estratrien-3,17 β-diol-6-one-6-carboxymethloxime-NH-propyl-biotin] resulted in agonist internalization. These results demonstrate that E2-mediated neuroprotection and ERK activation involve ERα activation of G-protein- and β-arrestin-mediated mechanisms.
Publication titleJournal of Neurochemistry
Department/SchoolTasmanian School of Medicine
PublisherBlackwell Publishing Ltd
Place of publicationOxford
Rights statementCopyright © 2009 Society for Neuroscience. This is the peer reviewed version of the following article: Dominguez, R., Hu, E., Zhou, M., Baudry, M., 2009. 17β-Estradiol-Mediated Neuroprotection and ERK Activation Require a Pertussis Toxin-Sensitive Mechanism Involving GRK2 and β-Arrestin-1, Journal of Neurochemistry, 29(13), 4228-4238 which has been published in final form at http://dx.doi.org/10.1523/JNEUROSCI.0550-09.2009 This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.