Loss of prion protein in a transgenic model of amyotrophic lateral sclerosis.
Amyotrophic lateral sclerosis (ALS) is a motor neuron degenerative disorder caused in a proportion of cases by missense mutations in the gene encoding Cu/Zn superoxide dismutase (Cu/Zn-SOD) which result in unknown, lethal enzymatic activity. Based on a differential screening approach, we show here that the gene encoding the cellular prion protein (PrP(C)) was specifically repressed in a transgenic model of ALS overexpressing the mutant G86R Cu/Zn-SOD. Analysis by Northern blot, semiquantitative RT-PCR, and Western blot revealed that PrP(C) down-regulation, which appeared early in the asymptomatic phase of the pathology, occurred preferentially in those tissues primarily affected by the disease (spinal cord, sciatic nerve, and gastrocnemius muscle). This down-regulation was not accompanied by refolding of the aberrant PrP(Sc) isoform, the agent which causes transmissible spongiform encephalopathies. Furthermore, modification of PrP(C) expression was specifically linked to the presence of the G86R mutant since no changes were observed in transgenic mice overexpressing wild-type Cu/Zn-SOD. PrP(C) has been shown to play a role in the protection against oxidative stress, and we therefore propose that its down-regulation may contribute at least in part to ALS pathogenesis.
Dupuis
Luc
L
Laboratoire de Signalisations Moléculaires et Neurodégénérescence, EA 3433 Faculté de Médecine, Université Louis Pasteur, Strasbourg, France.
Mbebi
Corinne
C
Gonzalez de Aguilar
José-Luis
JL
Rene
Frédérique
F
Muller
André
A
de Tapia
Marc
M
Loeffler
Jean-Philippe
JP
D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D000818:Animals; D004252:DNA Mutational Analysis; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000235:genetics*; D015723:Gene Library; D005820:Genetic Testing; D051379:Mice; D008822:Mice, Transgenic; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D018621:PrPC Proteins / Q000172:deficiency* / Q000235:genetics; D017510:Protein Folding; D012333:RNA, Messenger / Q000378:metabolism; D012584:Sciatic Nerve / Q000378:metabolism; D013116:Spinal Cord / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics* / Q000378:metabolism
D018832:Molecular Chaperones; D018621:PrPC Proteins; D012333:RNA, Messenger; D013482:Superoxide Dismutase