title: LRRK2 expression in idiopathic and G2019S positive Parkinson's disease subjects: a morphological and quantitative study.
abstract: OBJECTIVE
  Mutations in the gene encoding leucine-rich repeat kinase-2 (LRRK2) have been established as a common genetic cause of Parkinson's disease (PD). The distribution of LRRK2 mRNA and protein in the human brain has previously been described, although it has not been reported in PD cases with the common LRRK2 G2019S mutation.
  
  
  METHODS
  To further elucidate the role of LRRK2 in PD, we determined the localization of LRRK2 mRNA and protein in post-mortem brain tissue from control, idiopathic PD (IPD) and G2019S positive PD cases.
  
  
  RESULTS
  Widespread neuronal expression of LRRK2 mRNA and protein was recorded and no difference was observed in the morphological localization of LRRK2 mRNA or protein between control, IPD and G2019S positive PD cases. Using quantitative real-time polymerase chain reaction, we demonstrated that there is no regional variation in LRRK2 mRNA in normal human brain, but we have identified differential expression of LRRK2 mRNA with significant reductions recorded in limbic and neocortical regions of IPD cases compared with controls. Semi-quantitative analysis of LRRK2 immunohistochemical staining demonstrated regional variation in staining intensity, with weak LRRK2 immunoreactivity consistently recorded in the striatum and substantia nigra. No clear differences were identified in LRRK2 immunoreactivity between control, IPD and G2019S positive PD cases. LRRK2 protein was identified in a small proportion of Lewy bodies.
  
  
  CONCLUSIONS
  Our data suggest that widespread dysregulation of LRRK2 mRNA expression may contribute to the pathogenesis of IPD.
authors.affiliation: Queen Square Brain Bank, Department of Molecular Neuroscience, UCL Institute of Neurology, UCL, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Sharma
authors.forename: R
authors.initials: R
authors.lastname: Bandopadhyay
authors.forename: T
authors.initials: T
authors.lastname: Lashley
authors.forename: A E M
authors.initials: AE
authors.lastname: Renton
authors.forename: A E
authors.initials: AE
authors.lastname: Kingsbury
authors.forename: R
authors.initials: R
authors.lastname: Kumaran
authors.forename: C
authors.initials: C
authors.lastname: Kallis
authors.forename: C
authors.initials: C
authors.lastname: Vilariño-Güell
authors.forename: S S
authors.initials: SS
authors.lastname: O'Sullivan
authors.forename: A J
authors.initials: AJ
authors.lastname: Lees
authors.forename: T
authors.initials: T
authors.lastname: Revesz
authors.forename: N W
authors.initials: NW
authors.lastname: Wood
authors.forename: J L
authors.initials: JL
authors.lastname: Holton
mesh_terms: D001921:Brain / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; D008297:Male; D009154:Mutation; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D010300:Parkinson Disease / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism
chemical_list: C495280:LRRK2 protein, human; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; D017346:Protein Serine-Threonine Kinases