Protective Effect of Recombinant Adeno-Associated Virus 2/8-Mediated Gene Therapy from the Maternal Hyperphenylalaninemia in Offsprings of a Mouse Model of Phenylketonuria

Abstract

Phenylketonuria (PKU) is an autosomal recessively inherited metabolic disorder caused by a deficiency of phenylalanine hydroxylase (PAH). The accumulation of phenylalanine leads to severe mental and psychomotor retardation, and the fetus of an uncontrolled pregnant female patient presents with maternal PKU syndrome. We have reported previously on the cognitive outcome of biochemical and phenotypic reversal of PKU in a mouse model, Pahenu2, by the AAV serotype 2-mediated gene delivery of a human PAH transgene. However, the therapeutic efficacy had been limited to only male PKU mice. In this study, we generated a pseudotyped recombinant AAV2/8-hPAH vector and infused it into female PKU mice through the hepatic portal vein or tail vein. Two weeks after injection, complete fur color change to black was observed in female PKU, as in males. The PAH activity in the liver increased to 65-70% of the wild-type activity in female PKU mice and to 90% in male PKU mice. Plasma phenylalanine concentration in female PKU mice decreased to the normal value. In addition, the offsprings of the treated female PKU mice can rescue from the harmful effect of maternal hyperphenylalaninemia. These results indicate that recombinant AAV2/8-mediated gene therapy is a potential therapeutic strategy for PKU.

Clinical, genetic, and experimental research of hyperphenylalaninemia

“…• Long-term correction of HPA et al, 2020), which obtained a long-lasting correction of PAH activity in Pah enu2 mice. Similar observations were made using either the recombinant triplecistronic AAV2 pseudotype 1 vector (Ding et al, 2008) or the pseudotyped rAAV2/8-hPAH vector (Jung et al, 2008). Remarkably, the offspring of the treated mice were rescued from the pathologic effect (Jung et al, 2008).…”

“…Similar observations were made using either the recombinant triplecistronic AAV2 pseudotype 1 vector (Ding et al, 2008) or the pseudotyped rAAV2/8-hPAH vector (Jung et al, 2008). Remarkably, the offspring of the treated mice were rescued from the pathologic effect (Jung et al, 2008). In a comparative study, both the rAAV2 pseudotype 1 (rAAV2/1) and rAAV2/8 vectors showed the long-term phenylalanine clearance.…”

Protection of a Ceramide Synthase 2 Null Mouse from Drug-induced Liver Injury

“…The rep2/cap8 plasmid (p5E18-VD2/8, provided by Dr. Sung-Chul Jung (28,29), was used to package the expression vector. The recombinant adeno-associated virus (rAAV) carrying human CerS2 (rAAV2/8-CerS2) or GFP (rAAV2/8-eGFP) vectors were produced by the triple plasmid transfection method and purified by cesium chloride density gradient ultracentrifugation (28,30). The rAAV genomic titer was calculated using real-time PCR in which the signal from aliquots of the test FIGURE 2.…”

“…material were compared with a standard signal generated using the linearized pAAV2-EF-hCerS2-WPRE plasmid or pAAV-EF-eGFP-WPRE plasmid (28).…”

Long‐term correction of murine phenylketonuria by viral gene transfer: liver versus muscle

“…Quantitative TaqMan® analysis of WPRE DNA showed only extremely low rates of transduction of other tissues by the PAH vector. Treatment with an AAV2 serotype 8 vector was also shown to be effective in managing maternal PKU in mice (Jung et al 2008).…”