In vivo ribozyme targeting of betaAPP+ mRNAs.
In Alzheimer's disease (AD) and Down's syndrome (DS) patients, posttranscriptional alterations of sequences encoded by exon 9 and exon 10 of the beta-amyloid precursor protein (betaAPP) mRNA result in mutant proteins (betaAPP+) that colocalize with neurofibrillary tangles and senile plaques. These aberrant messages may contribute to the development of sporadic or late-onset Alzheimer's disease; thus, eliminating them or attenuating their expression could significantly benefit AD patients. In the present work, self-cleaving hammerhead ribozymes targeted to betaAPP exon 9 (Rz9) and betaAPP+ mutant exon 10 (Rz10) were examined for their ability to distinguish between betaAPP and betaAPP+ mRNA. In transiently transfected A-204 cells, quantitative confocal fluorescence microscopy showed that Rz9 preferentially lowered endogenous betaAPP. In contrast, in transient cotransfection experiments with betaAPP+ mRNAs containing a wild-type exon 9 and mutant exon 10 (betaAPP-9/betaAPP-10+1), or a mutant exon 9 and wild-type exon 10 (betaAPP-9+1/betaAPP-10) we found that Rz9 and Rz10 preferentially reduced betaAPP+ -mutant exon 10 mRNA in a concentration and a ribozyme-dependent manner.
Dolzhanskaya
N
N
Department of Molecular Biology, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York 10314, USA.
Conti
J
J
Merz
G
G
Denman
R B
RB
D016564:Amyloid beta-Protein Precursor / Q000235:genetics*; D015152:Blotting, Northern; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D005091:Exons / Q000187:drug effects / Q000235:genetics; D017930:Genes, Reporter; D006801:Humans; D009154:Mutation; D012323:RNA Processing, Post-Transcriptional; D016337:RNA, Catalytic / Q000378:metabolism* / Q000494:pharmacology; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D012208:Rhabdomyosarcoma / Q000378:metabolism; D013379:Substrate Specificity / Q000235:genetics; D014162:Transfection
D016564:Amyloid beta-Protein Precursor; D016337:RNA, Catalytic; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C427204:hammerhead ribozyme