A Nurr1 agonist causes neuroprotection in a Parkinson's disease lesion model primed with the toll-like receptor 3 dsRNA inflammatory stimulant poly(I:C)

PLoS One. 2015 Mar 27;10(3):e0121072. doi: 10.1371/journal.pone.0121072. eCollection 2015.

Abstract

Dopaminergic neurons in the substantia nigra pars compacta (SNpc) are characterized by the expression of genes required for dopamine synthesis, handling and reuptake and the expression of these genes is largely controlled by nuclear receptor related 1 (Nurr1). Nurr1 is also expressed in astrocytes and microglia where it functions to mitigate the release of proinflammatory cytokines and neurotoxic factors. Given that Parkinson's disease (PD) pathogenesis has been linked to both loss of Nurr1 expression in the SNpc and inflammation, increasing levels of Nurr1 maybe a promising therapeutic strategy. In this study a novel Nurr1 agonist, SA00025, was tested for both its efficiency to induce the transcription of dopaminergic target genes in vivo and prevent dopaminergic neuron degeneration in an inflammation exacerbated 6-OHDA-lesion model of PD. SA00025 (30mg/kg p.o.) entered the brain and modulated the expression of the dopaminergic phenotype genes TH, VMAT, DAT, AADC and the GDNF receptor gene c-Ret in the SN of naive rats. Daily gavage treatment with SA00025 (30mg/kg) for 32 days also induced partial neuroprotection of dopaminergic neurons and fibers in rats administered a priming injection of polyinosinic-polycytidylic acid (poly(I:C) and subsequent injection of 6-OHDA. The neuroprotective effects of SA00025 in this dopamine neuron degeneration model were associated with changes in microglial morphology indicative of a resting state and a decrease in microglial specific IBA-1 staining intensity in the SNpc. Astrocyte specific GFAP staining intensity and IL-6 levels were also reduced. We conclude that Nurr1 agonist treatment causes neuroprotective and anti-inflammatory effects in an inflammation exacerbated 6-OHDA lesion model of PD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Dopamine / biosynthesis*
  • Dopaminergic Neurons / metabolism
  • Dopaminergic Neurons / pathology
  • Gene Expression
  • Imidazoles / administration & dosage*
  • Inflammation / chemically induced
  • Inflammation / drug therapy*
  • Inflammation / metabolism
  • Inflammation / pathology
  • Male
  • Microglia / metabolism
  • Microglia / pathology
  • Nerve Degeneration / drug therapy
  • Nerve Degeneration / pathology
  • Neuroprotection / drug effects
  • Nuclear Receptor Subfamily 4, Group A, Member 2 / agonists
  • Nuclear Receptor Subfamily 4, Group A, Member 2 / genetics*
  • Oxidopamine / toxicity
  • Parkinson Disease, Secondary / drug therapy*
  • Parkinson Disease, Secondary / metabolism
  • Parkinson Disease, Secondary / pathology
  • Pars Compacta / drug effects
  • Pars Compacta / metabolism
  • Poly I-C / administration & dosage
  • Pyridines / administration & dosage*
  • RNA, Double-Stranded
  • Rats
  • Toll-Like Receptor 3 / biosynthesis*
  • Toll-Like Receptor 3 / genetics

Substances

  • Imidazoles
  • Nuclear Receptor Subfamily 4, Group A, Member 2
  • Pyridines
  • RNA, Double-Stranded
  • SA00025
  • TLR3 protein, human
  • Toll-Like Receptor 3
  • Oxidopamine
  • Poly I-C
  • Dopamine

Grant support

MJFF was the sole provider of support in the form of salaries for authors listed under McLean Hospital/Harvard Medical School. Sanofi and Sanofi–Genzyme provided support in the form of salaries for authors (TR, PB, MC and YL), but did not have any additional role in the study design, analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the "author contributions" section. Sanofi and Sanofi-Genzyme did collect PK data and reviewed the final completed manuscript. No changes were made to the manuscript by Sanofi and Sanofi-Genzyme to the data or interpretation.