Nurr1 Protein Is Required for N-Methyl-d-aspartic Acid (NMDA) Receptor-mediated Neuronal Survival*

+ Author Affiliations

From the ^‡Institut de Neurociencies and Departament de Bioquímica i Biología Molecular, Universitat Autònoma de Barcelona, 08193 Barcelona,
the ^§Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 08193 Barcelona,
the ^¶Diabetes and Obesity Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, and
the ^‖CIBER de Diabetes y Enfermedades Metabólicas (CIBERDEM), 08036 Barcelona, Spain

↵4 To whom correspondence should be addressed: Instituto de Neurociencias, Edificio M, Campus de Bellaterra, Universidad Autónoma de Barcelona, 08193 Cerdanyola del Valles, 08193 Barcelona, Spain. Tel.: 34-935-811-525; Fax: 34-935-811-573; E-mail: jose.rodriguez@uab.es.

Capsule

Background: The mechanism involved in activity-dependent survival of neurons in the central nervous system is not fully understood.

Results: Nurr1 is involved in excitatory transmission-dependent survival of glutamatergic neurons by acting downstream CREB and upstream of BDNF.

Conclusion: Nurr1 activation mediates activity-dependent survival of glutamatergic neurons.

Significance: A novel function of Nurr1 in activity-dependent survival of glutamatergic neurons is reported.

Abstract

NMDA receptor (NMDAR) stimulation promotes neuronal survival during brain development. Cerebellar granule cells (CGCs) need NMDAR stimulation to survive and develop. These neurons differentiate and mature during its migration from the external granular layer to the internal granular layer, and lack of excitatory inputs triggers their apoptotic death. It is possible to mimic this process in vitro by culturing CGCs in low KCl concentrations (5 mm) in the presence or absence of NMDA. Using this experimental approach, we have obtained whole genome expression profiles after 3 and 8 h of NMDA addition to identify genes involved in NMDA-mediated survival of CGCs. One of the identified genes was Nurr1, a member of the orphan nuclear receptor subfamily Nr4a. Our results report a direct regulation of Nurr1 by CREB after NMDAR stimulation. ChIP assay confirmed CREB binding to Nurr1 promoter, whereas CREB shRNA blocked NMDA-mediated increase in Nurr1 expression. Moreover, we show that Nurr1 is important for NMDAR survival effect. We show that Nurr1 binds to Bdnf promoter IV and that silencing Nurr1 by shRNA leads to a decrease in brain-derived neurotrophic factor (BDNF) protein levels and a reduction of NMDA neuroprotective effect. Also, we report that Nurr1 and BDNF show a similar expression pattern during postnatal cerebellar development. Thus, we conclude that Nurr1 is a downstream target of CREB and that it is responsible for the NMDA-mediated increase in BDNF, which is necessary for the NMDA-mediated prosurvival effect on neurons.

Footnotes

↵1 Recipient of a predoctoral fellowship from the Universitat Autònoma de Barcelona.
↵2 Recipient of a predoctoral fellowship from the Gobierno Vasco.
↵3 Recipient of a predoctoral fellowship from the Generalitat de Catalunya.
↵* This work was supported by grants from the Ministerio de Ciencia e Innovación (Grants SAF2008-01904, SAF2011-30281, and RENEVAS) and CIBERNED (Grant CB06/05/0042) (to J. R. A) and the Ministerio de Ciencia e Innovación (Grant SAF2010-20925) (to C. A. S.).
↵ This article contains supplemental Tables I–III and Figs. 1 and 2.