Post-treatment with PT302, a long-acting Exendin-4 sustained release formulation, reduces dopaminergic neurodegeneration in a 6-Hydroxydopamine rat model of Parkinson's disease

Sci Rep. 2018 Jul 16;8(1):10722. doi: 10.1038/s41598-018-28449-z.

Abstract

We previously demonstrated that pretreatment with Exendin-4, a glucagon-like peptide-1 (GLP-1) receptor agonist, reduces 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) -mediated dopaminergic neurodegeneration. The use of GLP-1 or Exendin-4 for Parkinson's disease (PD) patients is limited by their short half-lives. The purpose of this study was to evaluate a new extended release Exendin-4 formulation, PT302, in a rat model of PD. Subcutaneous administration of PT302 resulted in sustained elevations of Exendin-4 in plasma for >20 days in adult rats. To define an efficacious dose within this range, rats were administered PT302 once every 2 weeks either before or following the unilaterally 6-hydroxydopamine lesioning. Pre- and post-treatment with PT302 significantly reduced methamphetamine-induced rotation after lesioning. For animals given PT302 post lesion, blood and brain samples were collected on day 47 for measurements of plasma Exendin-4 levels and brain tyrosine hydroxylase immunoreactivity (TH-IR). PT302 significantly increased TH-IR in the lesioned substantia nigra and striatum. There was a significant correlation between plasma Exendin-4 levels and TH-IR in the substantia nigra and striatum on the lesioned side. Our data suggest that post-treatment with PT302 provides long-lasting Exendin-4 release and reduces neurodegeneration of nigrostriatal dopaminergic neurons in a 6-hydroxydopamine rat model of PD at a clinically relevant dose.

Publication types

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

MeSH terms

  • 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / administration & dosage
  • Animals
  • Corpus Striatum / cytology
  • Corpus Striatum / drug effects
  • Corpus Striatum / immunology
  • Corpus Striatum / pathology
  • Delayed-Action Preparations / administration & dosage
  • Disease Models, Animal
  • Dopaminergic Neurons / drug effects*
  • Dopaminergic Neurons / immunology
  • Dopaminergic Neurons / pathology
  • Dose-Response Relationship, Drug
  • Drug Administration Schedule
  • Exenatide / administration & dosage*
  • Humans
  • Incretins / administration & dosage*
  • Male
  • Oxidopamine / administration & dosage
  • Oxidopamine / toxicity
  • Parkinson Disease, Secondary / drug therapy*
  • Parkinson Disease, Secondary / etiology
  • Parkinson Disease, Secondary / immunology
  • Parkinson Disease, Secondary / pathology
  • Rats
  • Rats, Sprague-Dawley
  • Substantia Nigra / cytology
  • Substantia Nigra / drug effects
  • Substantia Nigra / immunology
  • Substantia Nigra / pathology
  • Treatment Outcome
  • Tyrosine 3-Monooxygenase / immunology

Substances

  • Delayed-Action Preparations
  • Incretins
  • Oxidopamine
  • Exenatide
  • 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine
  • Tyrosine 3-Monooxygenase