Effect of sex and gonadectomy on brain MPTP toxicity and response to dutasteride treatment in mice

Neuropharmacology. 2021 Dec 15;201:108784. doi: 10.1016/j.neuropharm.2021.108784. Epub 2021 Sep 20.

Abstract

The main neuropathological feature of Parkinson's disease (PD) is degeneration of dopamine (DA) neurons in the substantia nigra (SN); PD prevalence is higher in men, suggesting a role of sex hormones in neuroprotection. This study sought the effects of sex hormones in the brain in a mouse model of PD and modulation of steroid metabolism/synthesis with the 5α-reductase inhibitor dutasteride shown to protect 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) male mice. Male and female mice were gonadectomized (GDX) or SHAM operated. They were treated with vehicle or dutasteride (5 mg/kg) for 10 days and administered a low dose of MPTP (5.5 mg/kg) or saline on the 5th day to model early PD; brains were collected thereafter. Striatal measures of the active metabolite 1-methyl-4-phenylpyridinium (MPP+) contents showed no difference supporting an effect of the experimental conditions investigated. In SHAM MPTP male mice loss of striatal DA and metabolites, DA transporter (DAT) and vesicular monoamine transporter 2 (VMAT2) specific binding in the striatum and SN was prevented by dutasteride treatment; these changes were inversely correlated with glial fibrillary acidic protein (GFAP, an astrogliosis marker) levels. In SHAM female mice MPTP treatment had little or no effect on striatal and SN DA markers and GFAP levels whereas GDX male and female mice showed a similar loss of striatal DA markers and increase of GFAP. No effect of dutasteride treatment was observed in GDX male and female mice. In conclusion, sex differences in mice MPTP toxicity and response to dutasteride were observed that were lost upon gonadectomy implicating neuroinflammation.

Keywords: Dutasteride; Gonadectomy; MPTP; Parkinson's disease; Sex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / metabolism*
  • Animals
  • Castration*
  • Corpus Striatum / metabolism*
  • Disease Models, Animal
  • Dopamine / metabolism
  • Dutasteride / administration & dosage*
  • Dutasteride / pharmacology*
  • Female
  • Glial Fibrillary Acidic Protein / metabolism
  • Humans
  • Male
  • Mice, Inbred C57BL
  • Parkinson Disease / metabolism*
  • Sex Characteristics*
  • Substantia Nigra / metabolism*

Substances

  • Glial Fibrillary Acidic Protein
  • glial fibrillary astrocytic protein, mouse
  • 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine
  • Dutasteride
  • Dopamine