The aims of this study were to evaluate the expression of enhanced green fluorescent protein (EGFP) driven by 6 different promoters, including cytomegalovirus IE enhancer and chicken beta-actin promoter (CAG), cytomegalovirus promoter (CMV), neuron-specific enolase promoter (NSE), myosin 7A promoter (Myo), elongation factor 1alpha promoter (EF-1alpha), and Rous sarcoma virus promoter (RSV), and assess the dose response of CAG promoter to transgene expression in the cochlea. Serotype 1 adeno-associated virus (AAV1) vectors with various constructs were transduced into the cochleae, and the level of EGFP expression was examined. We found the highest EGFP expression in the inner hair cells and other cochlear cells when CAG promoter was used. The CMV and NSE promoter drove the higher EGFP expression, but only a marginal activity was observed in EF-1alpha promoter driven constructs. RSV promoter failed to driven the EGFP expression. Myo promoter driven EGFP was exclusively expressed in the inner hair cells of the cochlea. When driven by CAG promoter, reporter gene expression was detected in inner hair cells at a dose as low as 3 x 10(7) genome copies, and continued to increase in a dose- dependent manner. Our data showed that individual promoter has different ability to drive reporter gene expression in the cochlear cells. Our results might provide important information with regard to the role of promoters in regulating transgene expression and for the proper design of vectors for gene expression and gene therapy.
Animals ; Cochlea/cytology/*metabolism ; Dependovirus/*genetics ; Dose-Response Relationship, Drug ; Female ; Genetic Vectors/*genetics ; Green Fluorescent Proteins/metabolism ; Humans ; Mice ; Mice, Inbred C57BL ; Promoter Regions, Genetic/*genetics ; *Transgenes

Objective To examine whether tyrosine hydroxylase (TH) and aromatic L-amino acid decarboxylase (AADC) genes can be cotransduced into the same target striatal cells using adeno-associated virus (AAV) vectors, and to determine whether the cotransduction would result in better biochemical change than the TH gene alone.Methods TH and AADC genes were cotransduced into cultured striatal cells with separate AAV vectors. Expressions of TH and AADC were detected by immunocytochemistry; intracellular catecholamine levels were assayed by high-performance liquid chromatography (HPLC).Results TH and AADC genes were efficiently cotransduced into the striatal cells. Specifically, the coexpression of TH and AADC resulted in more effective dopamine production compared with the TH gene alone.Conclusion Using AAV vectors, coexpression of TH and AADC in the striatal cells might be a useful approach to gene therapy for Parkinson's disease.

Objective To explore triple gene transfer of dopamine synthetic enzymes with separate adeno-associated virus (AAV) vectors.Methods The genes for dopamine synthetic enzymes, tyrosine hydroxylase (TH), aromatic L-amino acid decarboxylase (AADC), and GTP cyclohydrolase Ⅰ (GCH, an enzyme critical for tetrahydrobiopterin synthesis) were cotransduced into 293 cells with separate AAV vectors. Expressions of TH, AADC and GCH were detected by Western blot analysis. Intracellular dopamine level was assayed by high-performance liquid chromatography.Results TH, AADC and GCH were effectively coexpressed in transduced cells with three separate AAV vectors, AAV-TH, AAV-AADC and AAV-GCH. Furthermore, the coexpression resulted in an effectively spontaneous dopamine production in cotransduced cells.Conclusion The triple transduction of TH, AADC and GCH genes with separate AAV vectors is effective, which might be important to gene therapy for Parkinson's disease.