title: Age-related Purkinje cell death is steroid dependent: RORα haplo-insufficiency impairs plasma and cerebellar steroids and Purkinje cell survival.
abstract: A major problem of ageing is progressive impairment of neuronal function and ultimately cell death. Since sex steroids are neuroprotective, their decrease with age may underlie age-related neuronal degeneration. To test this, we examined Purkinje cell numbers, plasma sex steroids and cerebellar neurosteroid concentrations during normal ageing (wild-type mice, WT), in our model of precocious ageing (Rora(+/sg), heterozygous staggerer mice in which expression of the neuroprotective factor RORα is disrupted) and after long-term hormone insufficiency (WT post-gonadectomy). During normal ageing (WT), circulating sex steroids declined prior to or in parallel with Purkinje cell loss, which began at 18 months of age. Although Purkinje cell death was advanced in WT long-term steroid deficiency, this premature neuronal loss did not begin until 9 months, indicating that vulnerability to sex steroid deficiency is a phenomenon of ageing Purkinje neurons. In precocious ageing (Rora(+/sg)), circulating sex steroids decreased prematurely, in conjunction with marked Purkinje cell death from 9 months. Although Rora(+/sg) Purkinje cells are vulnerable through their RORα haplo-insufficiency, it is only as they age (after 9 months) that sex steroid failure becomes critical. Finally, cerebellar neurosteroids did not decrease with age in either genotype or gender; but were profoundly reduced by 3 months in male Rora(+/sg) cerebella, which may contribute to the fragility of their Purkinje neurons. These data suggest that ageing Purkinje cells are maintained by circulating sex steroids, rather than local neurosteroids, and that in Rora(+/sg) their age-related death is advanced by premature sex steroid loss induced by RORα haplo-insufficiency.
authors.affiliation: UMR Neurobiologie des Processus Adaptatifs, UPMC Univ Paris, France.
authors.forename: Sonja
authors.initials: S
authors.lastname: Janmaat
authors.forename: Yvette
authors.initials: Y
authors.lastname: Akwa
authors.forename: Mohamed
authors.initials: M
authors.lastname: Doulazmi
authors.forename: Joëlle
authors.initials: J
authors.lastname: Bakouche
authors.forename: Vanessa
authors.initials: V
authors.lastname: Gautheron
authors.forename: Philippe
authors.initials: P
authors.lastname: Liere
authors.forename: Bernard
authors.initials: B
authors.lastname: Eychenne
authors.forename: Antoine
authors.initials: A
authors.lastname: Pianos
authors.forename: Paul
authors.initials: P
authors.lastname: Luiten
authors.forename: Ton
authors.initials: T
authors.lastname: Groothuis
authors.forename: Etienne-Emile
authors.initials: EE
authors.lastname: Baulieu
authors.forename: Jean
authors.initials: J
authors.lastname: Mariani
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Sherrard
authors.forename: Florence
authors.initials: F
authors.lastname: Frédéric
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D002369:Castration; D002452:Cell Count; D016923:Cell Death / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology*; D002531:Cerebellum / Q000166:cytology / Q000378:metabolism*; D004958:Estradiol / Q000097:blood; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism / Q000502:physiology*; D020249:Hormone Replacement Therapy; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D008818:Mice, Neurologic Mutants; D057094:Nuclear Receptor Subfamily 1, Group F, Member 1 / Q000502:physiology*; D011374:Progesterone / Q000097:blood; D011689:Purkinje Cells / Q000166:cytology / Q000502:physiology*; D013739:Testosterone / Q000097:blood
chemical_list: D012739:Gonadal Steroid Hormones; D057094:Nuclear Receptor Subfamily 1, Group F, Member 1; C539738:RORA protein, human; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol