Elsevier

Neuroscience

Volume 129, Issue 3, 2004, Pages 629-637
Neuroscience

Rapid actions of estradiol on cyclic amp response-element binding protein phosphorylation in dorsal root ganglion neurons

https://doi.org/10.1016/j.neuroscience.2004.08.019Get rights and content

Abstract

Actions of gonadal steroids have not been widely investigated in the peripheral nervous system, although many dorsal root ganglion (DRG) and autonomic pelvic ganglion (PG) neurons express estrogen receptors (ERs). We have studied the effects of 17β-estradiol exposure on cultured DRG and PG neurons from adult rats. Western blotting analysis of DRG extracts detected phosphorylation of ERK1 and ERK2 (extracellular signal-regulated kinases) that peaked 10 min after exposure to 17β-estradiol. These extracts contain both neurons and glia; therefore, to determine if this response occurred in DRG neurons, we developed an immunocytochemical method to specifically measure activation in individual neurons. These measurements showed that estradiol increased phosphorylation of CREB (cyclic AMP response-element binding protein), which was consistently blocked by the ERK pathway inhibitor PD98059 but not by the inhibitors of phosphatidylinositol 3-kinase, wortmannin and LY294002. 17β-Estradiol activation of CREB in DRG neurons was reduced by the ER antagonist, ICI182780. In contrast, in PG neurons estradiol did not affect CREB phosphorylation, highlighting a difference in E2 responses in different populations of peripheral neurons. This study has shown that estrogens can rapidly activate signaling pathways associated with CREB-mediated transcriptional regulation in sensory neurons. As these pathways also mediate many effects of neurotrophic factors, changes in estrogen levels (e.g. during puberty, pregnancy or menopause) could have broad-ranging genomic and non-genomic actions on urogenital pain sensation and reflex pathways.

Section snippets

Neuronal cultures

Adult outbred Wistar rats (200–300 g) were used for the experiments. All experiments were performed in accordance with the National Health and Medical Research Council of Australia's Code of Practice for the Care and Use of Animals for Experimental Purposes, which also conforms to standard international guidelines. Every attempt was made to reduce the number of animals used and to minimise their suffering. Animals were deeply anesthetized (sodium pentobarbitone, 48 mg/kg, i.p.) prior to

Estradiol activates ERK in primary sensory neurons

Western blot analysis of cultured DRG neurons showed that treatment with estradiol (10 nM) induced phosphorylation of p44 (ERK1) and p42 ERK (ERK2) by 10 min and this was still elevated at 60 min (Fig. 1A). Data have been normalized to 10 min control data. The 30 and 60 min controls decrease relative to the 10 min control because ERK activation occurring in response to the action of treating the cells (movement of culture dish, temperature change, light) decreases rapidly over this period (Fig.

Discussion

CREB is a critical molecule associated with neuronal plasticity and adaptation, and CREB activation via ERK and PI3-K is a key target of neurotrophin-activated signaling pathways (Shaywitz and Greenberg, 1999). We visualized CREB activation in cultures of adult DRG and identified individual sensory neurons that respond rapidly to estradiol in vitro. In these neurons, estradiol exposure resulted in CREB phosphorylation and this occurred via activation of the ERK pathway and did not involve the

Acknowledgments

This work was supported by the National Health and Medical Research Council (Australia), Project grant 990034 and Senior Research Fellowship 157213, and University of New South Wales Faculty Research grant to J.R.K. We are grateful to Peregrine Osborne for valuable discussions.

References (35)

  • L. Carlstrom et al.

    Estrogen modulation of the cyclic AMP response element-binding protein pathway: effects of long-term and acute treatments

    Neuroendocrinology

    (2001)
  • P.R. Gangula et al.

    Regulation of calcitonin gene-related peptide expression in dorsal root ganglia of rats by female sex steroid hormones

    Biol Reprod

    (2000)
  • K. Honda et al.

    Phosphatidylinositol 3-kinase mediates neuroprotection by estrogen in cultured cortical neurons

    J Neurosci Res

    (2000)
  • E.J. Huang et al.

    Neurotrophins: roles in neuronal development and function

    Annu Rev Neurosci

    (2001)
  • J.R. Keast et al.

    Differential regulation of trkA and p75 in noradrenergic pelvic autonomic ganglion cells after deafferentation of their cholinergic neighbours

    Eur J Neurosci

    (2001)
  • G.G. Kuiper et al.

    Cloning of a novel receptor expressed in rat prostate and ovary

    Proc Natl Acad Sci USA

    (1996)
  • P. Lanlua et al.

    Female steroid hormones modulate receptors for nerve growth factor in rat dorsal root ganglia

    Biol Reprod

    (2001)
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