title: Complete restoration of phenylalanine oxidation in phenylketonuria mouse by a self-complementary adeno-associated virus vector.
abstract: BACKGROUND
  Classical phenylketonuria (PKU) arises from a deficiency of phenylalanine hydroxylase (PAH) that catalyses phenylalanine oxidation in the liver. Lack of PAH activity causes massive hyperphenylalaninemia and consequently severe brain damage. Preclinical studies showed that conventional adeno-associated virus (AAV) vectors could correct hyperphenylalaninemia in a mouse model of PKU, although limitations such as very large dose requirement and relative inefficiency in female animals were recognized.
  
  
  METHODS
  An AAV8-pseudotyped vector was constructed with a self-complementary AAV (scAAV) genome for efficient liver transduction and expression. Following vector injection to PKU mice, blood Phe was periodically measured by an enzymatic fluorometric assay. In vivo Phe oxidation was evaluated by a non-invasive breath test using [1-(13) C]Phe. Vector copy number in the host tissues was determined by quantitative polymerase chain reaction.
  
  
  RESULTS
  A single injection of 1 × 10(11) -1 × 10(12) particles of the scAAV8 vector resulted in a reduction of blood Phe to normal or near-normal levels for more than 1 year in both genders. The treated animals showed normal level of in vivo Phe oxidation. The presence of > 1 copy of vector DNA per diploid genome in the liver was associated with normal blood Phe in the AAV-treated PKU mice.
  
  
  CONCLUSIONS
  Complete phenotypic correction of PKU mice was achieved by the scAAV8 vector for the longest duration reported to date. The vector overcame the female-specific disadvantage in AAV-mediated liver transduction; thus, it offers a promising platform of long-lasting gene therapy for PKU.
authors.affiliation: Division of Genetic Therapeutics, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Japan.
authors.forename: Hiroya
authors.initials: H
authors.lastname: Yagi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ogura
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Mizukami
authors.forename: Masashi
authors.initials: M
authors.lastname: Urabe
authors.forename: Hiromi
authors.initials: H
authors.lastname: Hamada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Keiya
authors.initials: K
authors.lastname: Ozawa
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kume
mesh_terms: D000818:Animals; D000229:Dependovirus / Q000235:genetics; D005260:Female; D023061:Gene Order; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000821:virology; D008297:Male; D051379:Mice; D010084:Oxidation-Reduction; D010649:Phenylalanine / Q000378:metabolism; D010651:Phenylalanine Hydroxylase / Q000235:genetics* / Q000378:metabolism*; D010661:Phenylketonurias / Q000201:enzymology* / Q000235:genetics / Q000628:therapy*; D013997:Time Factors; D014161:Transduction, Genetic
chemical_list: D010649:Phenylalanine; D010651:Phenylalanine Hydroxylase