Eicosanoid receptor subtype-mediated opposing regulation of TLR-stimulated expression of astrocyte glial-derived neurotrophic factor

FASEB J. 2012 Jul;26(7):3075-83. doi: 10.1096/fj.11-200279. Epub 2012 Apr 12.

Abstract

A major therapeutic target for Parkinson's disease (PD) is providing increased glial-derived neurotrophic factor (GDNF) to dopaminergic neurons. We tested the hypothesis that innate immune activation increases astrocyte GDNF production and that this is regulated by specific eicosanoid receptors. Innate immune-activated primary murine astrocytes were assayed for GDNF expression and secretion. Controls were agent vehicle exposure and wild-type mice. Rank order for up to 10-fold selectively increased GDNF expression was activators of TLR3 > TLR2 or TLR4 > TLR9. TLR3 activator-stimulated GDNF expression was selectively JNK-dependent, followed cyclooxygenase (COX)-2, was coincident with membranous PGE(2) synthase, and was not significantly altered by a nonspecific COX- or a COX-2-selective inhibitor. Specific eicosanoid receptors had opposing effects on TLR3 activator-induced GDNF expression: ∼60% enhancement by blocking or ablating of PGE(2) receptor subtype 1 (EP1), ∼30% enhancement by activating PGF(2α) receptor or thromboxane receptor, or ∼15% enhancement by activating EP4. These results demonstrate functionally antagonistic eicosanoid receptor subtype regulation of innate immunity-induced astrocyte GDNF expression and suggest that selective inhibition of EP1 signaling might be a means to augment astrocyte GDNF secretion in the context of innate immune activation in diseased regions of brain in PD.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / immunology
  • Astrocytes / metabolism*
  • Base Sequence
  • Cells, Cultured
  • DNA Primers / genetics
  • Glial Cell Line-Derived Neurotrophic Factor / deficiency
  • Glial Cell Line-Derived Neurotrophic Factor / genetics
  • Glial Cell Line-Derived Neurotrophic Factor / metabolism*
  • Immunity, Innate
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Models, Biological
  • Receptors, Eicosanoid / classification
  • Receptors, Eicosanoid / metabolism*
  • Receptors, Prostaglandin E, EP1 Subtype / metabolism
  • Toll-Like Receptor 2 / metabolism
  • Toll-Like Receptor 3 / metabolism
  • Toll-Like Receptor 4 / metabolism
  • Toll-Like Receptor 9 / metabolism
  • Toll-Like Receptors / metabolism*

Substances

  • DNA Primers
  • Gdnf protein, mouse
  • Glial Cell Line-Derived Neurotrophic Factor
  • Ptger1 protein, mouse
  • Receptors, Eicosanoid
  • Receptors, Prostaglandin E, EP1 Subtype
  • TLR3 protein, mouse
  • Tlr2 protein, mouse
  • Tlr4 protein, mouse
  • Tlr9 protein, mouse
  • Toll-Like Receptor 2
  • Toll-Like Receptor 3
  • Toll-Like Receptor 4
  • Toll-Like Receptor 9
  • Toll-Like Receptors