CTG repeat-targeting oligonucleotides for down-regulating Huntingtin expression.
Huntington's disease (HD) is a fatal, neurodegenerative disorder in which patients suffer from mobility, psychological and cognitive impairments. Existing therapeutics are only symptomatic and do not significantly alter the disease progression or increase life expectancy. HD is caused by expansion of the CAG trinucleotide repeat region in exon 1 of the Huntingtin gene (HTT), leading to the formation of mutant HTT transcripts (muHTT). The toxic gain-of-function of muHTT protein is a major cause of the disease. In addition, it has been suggested that the muHTT transcript contributes to the toxicity. Thus, reduction of both muHTT mRNA and protein levels would ideally be the most useful therapeutic option. We herein present a novel strategy for HD treatment using oligonucleotides (ONs) directly targeting the HTT trinucleotide repeat DNA. A partial, but significant and potentially long-term, HTT knock-down of both mRNA and protein was successfully achieved. Diminished phosphorylation of HTT gene-associated RNA-polymerase II is demonstrated, suggestive of reduced transcription downstream the ON-targeted repeat. Different backbone chemistries were found to have a strong impact on the ON efficiency. We also successfully use different delivery vehicles as well as naked uptake of the ONs, demonstrating versatility and possibly providing insights for in vivo applications.
Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, SE-141 86 Huddinge, Stockholm, Sweden.|Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, El-Khartoum square, Azareeta, 21 521 Alexandria, Egypt.
Eman M
EM
Zaghloul
Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, SE-141 86 Huddinge, Stockholm, Sweden.
Olof
O
Gissberg
Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, SE-141 86 Huddinge, Stockholm, Sweden.|Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135, Porto, Portugal.
Pedro M D
PMD
Moreno
Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden, SE-141 86, Huddinge, Stockholm, Sweden.
Lee
L
Siggens
Department of Neurochemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
Mattias
M
Hällbrink
Department of Physics and Chemistry, Nucleic Acid Centre University of Southern Denmark, DK-5230 Odense, Denmark.
Anna S
AS
Jørgensen
Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden, SE-141 86, Huddinge, Stockholm, Sweden.
Karl
K
Ekwall
Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, SE-141 86 Huddinge, Stockholm, Sweden.|Department of Clinical Genetics, Centre for Rare Diseases, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
Rula
R
Zain
Department of Physics and Chemistry, Nucleic Acid Centre University of Southern Denmark, DK-5230 Odense, Denmark.
Jesper
J
Wengel
Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, SE-141 86 Huddinge, Stockholm, Sweden.
Karin E
KE
Lundin
Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, SE-141 86 Huddinge, Stockholm, Sweden.
C I Edvard
CIE
Smith
D000483:Alleles; D004247:DNA / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D055785:Gene Knockdown Techniques; D006801:Humans; D000071058:Huntingtin Protein / Q000235:genetics* / Q000378:metabolism; D009691:Nucleic Acid Denaturation / Q000187:drug effects; D010455:Peptides / Q000378:metabolism; D054735:Phosphorothioate Oligonucleotides / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D010768:Phosphoserine / Q000378:metabolism; D012319:RNA Polymerase II / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015183:Restriction Mapping; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*; D014466:Ultraviolet Rays
D000071058:Huntingtin Protein; D010455:Peptides; D054735:Phosphorothioate Oligonucleotides; D012333:RNA, Messenger; D010768:Phosphoserine; D004247:DNA; D012319:RNA Polymerase II