Antisense oligonucleotide-based therapy in human erythropoietic protoporphyria.
Am J Hum Genet
; 94(4): 611-7, 2014 Apr 03.
Article
en En
| MEDLINE
| ID: mdl-24680888
ABSTRACT
In 90% of people with erythropoietic protoporphyria (EPP), the disease results from the inheritance of a common hypomorphic FECH allele, encoding ferrochelatase, in trans to a private deleterious FECH mutation. The activity of the resulting FECH enzyme falls below the critical threshold of 35%, leading to the accumulation of free protoporphyrin IX (PPIX) in bone marrow erythroblasts and in red cells. The mechanism of low expression involves a biallelic polymorphism (c.315-48T>C) localized in intron 3. The 315-48C allele increases usage of the 3' cryptic splice site between exons 3 and 4, resulting in the transcription of an unstable mRNA with a premature stop codon, reducing the abundance of wild-type FECH mRNA, and finally reducing FECH activity. Through a candidate-sequence approach and an antisense-oligonucleotide-tiling method, we identified a sequence that, when targeted by an antisense oligonucleotide (ASO-V1), prevented usage of the cryptic splice site. In lymphoblastoid cell lines derived from symptomatic EPP subjects, transfection of ASO-V1 reduced the usage of the cryptic splice site and efficiently redirected the splicing of intron 3 toward the physiological acceptor site, thereby increasing the amount of functional FECH mRNA. Moreover, the administration of ASO-V1 into developing human erythroblasts from an overtly EPP subject markedly increased the production of WT FECH mRNA and reduced the accumulation of PPIX to a level similar to that measured in asymptomatic EPP subjects. Thus, EPP is a paradigmatic Mendelian disease in which the in vivo correction of a common single splicing defect would improve the condition of most affected individuals.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Oligonucleótidos Antisentido
/
Protoporfiria Eritropoyética
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Ferroquelatasa
Límite:
Female
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Humans
/
Male
Idioma:
En
Revista:
Am J Hum Genet
Año:
2014
Tipo del documento:
Article
País de afiliación:
Francia