Coexpression of Tyrosine Hydroxylase, GTP Cyclohydrolase I, Aromatic Amino Acid Decarboxylase, and Vesicular Monoamine Transporter 2 from a Helper Virus-Free Herpes Simplex Virus Type 1 Vector Supports High-Level, Long-Term Biochemical and Behavioral Correction of a Rat Model of Parkinson's Disease

Abstract

Parkinson's disease is due to the selective loss of nigrostriatal dopaminergic neurons. Consequently, many therapeutic strategies have focused on restoring striatal dopamine levels, including direct gene transfer to striatal cells, using viral vectors that express specific dopamine biosynthetic enzymes. The central hypothesis of this study is that coexpression of four dopamine biosynthetic and transporter genes in striatal neurons can support the efficient production and regulated, vesicular release of dopamine: tyrosine hydroxylase (TH) converts tyrosine to L-3,4-dihydroxyphenylalanine (L -DOPA), GTP cyclohydrolase I (GTP CH I) is the rate-limiting enzyme in the biosynthesis of the cofactor for TH, aromatic amino acid decarboxylase (AADC) converts L -DOPA to dopamine, and a vesicular monoamine transporter (VMAT-2) transports dopamine into synaptic vesicles, thereby supporting regulated, vesicular release of dopamine and relieving feedback inhibition of TH by dopamine. Helper virus-free herpes simplex virus type 1 vectors that coexpress the three dopamine biosynthetic enzymes (TH, GTP CH I, and AADC; 3-gene-vector) or these three dopamine biosynthetic enzymes and the vesicular monoamine transporter (TH, GTP CH I, AADC, and VMAT-2; 4-gene-vector) were compared. Both vectors supported production of dopamine in cultured fibroblasts. These vectors were microinjected into the striatum of 6-hydroxydopamine-lesioned rats. These vectors carry a modified neurofilament gene promoter, and γ-aminobutyric acid (GABA)-ergic neuronspecific gene expression was maintained for 14 months after gene transfer. The 4-gene-vector supported higher levels of correction of apomorphine-induced rotational behavior than did the 3-gene-vector, and this correction was maintained for 6 months. Proximal to the injection sites, the 4-gene-vector, but not the 3-gene-vector, supported extracellular levels of dopamine and dihydroxyphenylacetic acid (DOPAC) that were similar to those observed in normal rats, and only the 4-gene-vector supported significant K + -dependent release of dopamine. OVERVIEW SUMMARY

Neurotransmitter release: vacuolar ATPase V0 sector c-subunits in possible gene or cell therapies for Parkinson’s, Alzheimer’s, and psychiatric diseases

“…Several groups have found that ChAT and VAChT genes are adjacent and co-regulated 14 forming a cholinergic genomic locus (see for example [37]). Though we do not now that N18TG-2 cells equip with the VAChT and synaptic vesicles, we cannot exclude the possibility that the transfection with ATP6V0C may induce vesicle formation and transporter expression.…”

“…ATP6V0C plays a central role in H + transport as one part of the multi-subunit complex of ATPase [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. Israel and his group initially proposed that medatophore forms a proteinaceous pore by the six transmemebrane c subunits of ATPase [10,11].…”

“…However, Israel's hypothesis about ATP6V0C in neurotransmitter release must be delineate by considering that V-ATPase is widely expressed in most types of cells and that, if ATP6V0C is indeed non-selectively permeable to cationic neurotransmitters [37,[42][43][44]]. It is highly likely that ATP6V0C is also permeable to much smaller ions, like Na + and K + [44] Thus ionic currents through ATP6V0C might be recordable using an electrophysiological technique, when ATP6V0C is overexpressed in the plasma membrane.…”

Genetic Enhancement of Visual Learning by Activation of Protein Kinase C Pathways in Small Groups of Rat Cortical Neurons

“…An enhancer from the tyrosine hydroxylase promoter (TH) (Ϫ0.5 to Ϫ6.8 kb) was fused to the 5Ј end of the neurofilament heavy gene promoter (NFH) (0.6 kb); and the chicken ␤-globin insulator (INS) (1.2 kb) was fused to the 5Ј end of the TH enhancer (Zhang et al, 2000). This promoter (INS-TH-NFH promoter) supported expression in forebrain neurons for 6 or 14 months, the longest times examined, and time courses in the striatum and the hippocampus documented expression in similar numbers of cells at times approximating the beginning and end of the testing of new object sets (Zhang et al, 2000;Sun et al, 2004) (supplemental Table S1, available at www.jneurosci.org as supplemental material).…”

Intra-neuronal vesicular uptake of catecholamines is decreased in patients with Lewy body diseases

“…Mice with low type 2 VMAT have motor and non-motor manifestations similar to those in PD (45). Moreover, inhibition of vesicular sequestration augments the toxicity of a variety of agents such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (46, 47) and 6-hydroxydopamine (48). Conversely, the pesticide and complex I inhibitor rotenone inhibits vesicular uptake (49,50), increases production of DOPAL (51), and evokes apoptosis via oxidation of cytosolic dopamine (52).…”