Parkinson phenotype in aged PINK1-deficient mice is accompanied by progressive mitochondrial dysfunction in absence of neurodegeneration.
BACKGROUND
Parkinson's disease (PD) is an adult-onset movement disorder of largely unknown etiology. We have previously shown that loss-of-function mutations of the mitochondrial protein kinase PINK1 (PTEN induced putative kinase 1) cause the recessive PARK6 variant of PD.


RESULTS
Now we generated a PINK1 deficient mouse and observed several novel phenotypes: A progressive reduction of weight and of locomotor activity selectively for spontaneous movements occurred at old age. As in PD, abnormal dopamine levels in the aged nigrostriatal projection accompanied the reduced movements. Possibly in line with the PARK6 syndrome but in contrast to sporadic PD, a reduced lifespan, dysfunction of brainstem and sympathetic nerves, visible aggregates of alpha-synuclein within Lewy bodies or nigrostriatal neurodegeneration were not present in aged PINK1-deficient mice. However, we demonstrate PINK1 mutant mice to exhibit a progressive reduction in mitochondrial preprotein import correlating with defects of core mitochondrial functions like ATP-generation and respiration. In contrast to the strong effect of PINK1 on mitochondrial dynamics in Drosophila melanogaster and in spite of reduced expression of fission factor Mtp18, we show reduced fission and increased aggregation of mitochondria only under stress in PINK1-deficient mouse neurons.


CONCLUSIONS
Thus, aging Pink1(-/-) mice show increasing mitochondrial dysfunction resulting in impaired neural activity similar to PD, in absence of overt neuronal death.
Gispert
Suzana
S
Department of Neurology, University Medical School, Frankfurt am Main, Germany.
Ricciardi
Filomena
F
Kurz
Alexander
A
Azizov
Mekhman
M
Hoepken
Hans-Hermann
HH
Becker
Dorothea
D
Voos
Wolfgang
W
Leuner
Kristina
K
Müller
Walter E
WE
Kudin
Alexei P
AP
Kunz
Wolfram S
WS
Zimmermann
Annabelle
A
Roeper
Jochen
J
Wenzel
Dirk
D
Jendrach
Marina
M
García-Arencíbia
Moisés
M
Fernández-Ruiz
Javier
J
Huber
Leslie
L
Rohrer
Hermann
H
Barrera
Miguel
M
Reichert
Andreas S
AS
Rüb
Udo
U
Chen
Amy
A
Nussbaum
Robert L
RL
Auburger
Georg
G
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology*; D019636:Neurodegenerative Diseases / Q000235:genetics / Q000473:pathology*; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D010300:Parkinson Disease / Q000175:diagnosis* / Q000235:genetics*; D010641:Phenotype; D011494:Protein Kinases / Q000235:genetics; D051844:alpha-Synuclein / Q000096:biosynthesis; D000099202:PTEN-Induced Putative Kinase
D000255:Adenosine Triphosphate; D011494:Protein Kinases; D051844:alpha-Synuclein; D000099202:PTEN-Induced Putative Kinase