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Neuroscience 1999;92(1):185-96

Long-term restoration of striatal L-aromatic amino acid decarboxylase
activity using recombinant adeno-associated viral vector gene transfer in a
rodent model of Parkinson's disease.

Leff SE, Spratt SK, Snyder RO, Mandel RJ
Department of Neurology, Yerkes Regional Primate Research Center, Emory
University, Atlanta, GA 30329, USA.

As a potential treatment for Parkinson's disease, viral vector-mediated
over-expression of striatal L-aromatic amino acid decarboxylase was tested
in an attempt to facilitate the production of therapeutic levels of dopamine
after peripheral L-dihydroxyphenylalanine administration. The results of
microdialysis and enzyme activity assays indicate that striatal
decarboxylation of peripherally administered L-dihydroxyphenylalanine was
enhanced by recombinant adeno-associated virus-mediated gene transfer of
L-aromatic amino acid decarboxylase in unilateral 6-hydroxydopamine-lesioned
rats. This gene transfer-induced increase in striatal decarboxylase activity
was shown to remain undiminished over a six-month period and transgene
expression was demonstrated to persist for at least one year. Unlike
previous approaches involving delivery of either tyrosine hydroxylase, or
tyrosine hydroxylase and L-aromatic amino acid decarboxylase transgenes
together to accomplish unregulated dopamine delivery, the current study
proposes a pro-drug strategy (peripheral L-dihydroxyphenylalanine
administration after L-aromatic amino acid decarboxylase transduction). This
strategy for dosage control could potentially allow lowered
L-dihydroxyphenylalanine doses and potentially obviate complicated
transcriptional regulation paradigms. These data suggest that the use of the
non-pathogenic adeno-associated virus to transfer the L-aromatic amino acid
decarboxylase gene into the striatum of Parkinson's disease patients may be
an attractive gene therapy strategy.

PMID: 10392841, UI: 99320012
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