The aim of the present study is to detect a combination method to utilize gene therapy for the treatment of Parkinson’s disease (PD). Here, a PD rat model is used for the in vivo gene therapy of a recombinant adeno-associated virus (AAV2) containing a human glutamic acid decarboxylase 65 (rAAV2-hGAD65) gene delivered to the subthalamic nucleus (STN). This is combined with the ex vivo gene delivery of tyrosine hydroxylase (TH) by fibroblasts injected into the striatum. After the treatment, the rotation behavior was improved with the greatest efficacy in the combination group. The results of immunohistochemistry showed that hGAD65 gene delivery by AAV2 successfully led to phenotypic changes of neurons in STN. And the levels of glutamic acid and GABA in the internal segment of the globus pallidus (GPi) and substantia nigra pars reticulata (SNr) were obviously lower than the control groups. However, hGAD65 gene transfer did not effectively protect surviving dopaminergic neurons in the SNc and VTA. This study suggests that subthalamic hGAD65 gene therapy and combined with TH gene therapy can alleviate symptoms of the PD model rats, independent of the protection the DA neurons from death. 1. Introduction The hallmark feature of Parkinson’s disease (PD) is degeneration of dopamine neurons in the substantia nigra pars compacta (SNc) and a consequent striatal dopamine deficiency [1–3]. Current clinic treatments for PD mainly focus on alleviating the symptoms with L-3,4-dihydroxyphenylalanine, which increases the synthesis and release of dopamine (DA), particularly during early stages of the disease [4–7]. As the disease progresses, however, pharmacological therapies cannot arrest or reverse neurodegeneration of dopaminergic neurons, and the effectiveness of treatment progressively decreases. Gene therapy techniques may provide an interesting alternative to the treatment of PD. Previous studies have focused on dopamine restoration in the neurotransmitter-depleted and denervated striatum [8, 9] by introducing essential enzymes for dopamine production, such as tyrosine hydroxylase (TH) [10–14], aromatic L-amino acid decarboxylase (AADC) [15, 16], and guanosine triphosphate (GTP) cyclohydrolase I (GTPC-I) [1, 17]. This strategy could potentially increase dopamine levels in the striatum and then improve symptoms in PD rat models. Actually, the dopamine deficiency in PD leads to a cascade of functional changes in basal ganglia circuitry [2, 3]. The essential pathophysiological characteristic of the PD state is increased neuronal firing activity in the output nuclei of
References
[1]
C. Bencsics, S. R. Wachtel, S. Milstien, K. Hatakeyama, J. B. Becker, and U. J. Kang, “Double transduction with GTP cyclohydrolase I and tyrosine hydroxylase is necessary for spontaneous synthesis of L-DOPA by primary fibroblasts,” Journal of Neuroscience, vol. 16, no. 14, pp. 4449–4456, 1996.
[2]
T. N. Chase, F. Baronti, G. Fabbrini, I. J. Heuser, J. L. Juncos, and M. M. Mouradian, “Rationale for continuous dopaminomimetic therapy of Parkinson's disease,” Neurology, vol. 39, no. 11, pp. 7–10, 1989.
[3]
T. Wichmann and J. O. Dostrovsky, “Pathological basal ganglia activity in movement disorders,” Neuroscience, vol. 198, pp. 232–244, 2011.
[4]
J. M. Brotchie, J. Lee, and K. Venderova, “Levodopa-induced dyskinesia in Parkinson's disease,” Journal of Neural Transmission, vol. 112, no. 3, pp. 359–391, 2005.
[5]
H. Bernheimer, W. Birkmayer, and O. Hornykiewicz, “Brain dopamine and the syndromes of Parkinson and Huntington. Clinical, morphological and neurochemical correlations,” Journal of the Neurological Sciences, vol. 20, no. 4, pp. 415–455, 1973.
[6]
S. Fahn, “Levodopa in the treatment of Parkinson's disease,” Journal of Neural Transmission, no. 71, pp. 1–15, 2006.
[7]
L. J. Fisher, H. A. Jinnah, L. C. Kale, G. A. Higgins, and F. H. Gage, “Survival and function of intrastriatally grafted primary fibroblasts genetically modified to produce L-dopa,” Neuron, vol. 6, no. 3, pp. 371–380, 1991.
[8]
C. L. Duan, Y. Su, C. L. Zhao, L. L. Lu, Q. Y. Xu, and H. Yang, “The assays of activities and function of TH, AADC, and GCH1 and their potential use in ex vivo gene therapy of PD,” Brain Research Protocols, vol. 16, no. 1–3, pp. 37–43, 2005.
[9]
S. I. Muramatsu, A. Kume, M. Matsumura et al., “Behavioral recovery in a primate model of Parkinson's disease by triple transduction of striatal cells with adeno-associated viral vectors expressing dopamine-synthesizing enzymes,” Human Gene Therapy, vol. 13, no. 3, pp. 345–354, 2002.
[10]
A. Bj？rklund, T. Bj？rklund, and D. Kirik, “Gene therapy for dopamine replacement in Parkinson's disease,” Science Translational Medicine, vol. 1, no. 2, p. 2ps2, 2009.
[11]
M. J. During, J. R. Naegele, K. L. O'Malley, and A. I. Geller, “Long-term behavioral recovery in parkinsonian rats by an HSV vector expressing tyrosine hydroxylase,” Science, vol. 266, no. 5189, pp. 1399–1403, 1994.
[12]
O. Corti, A. Sánchez-Capelo, P. Colin, N. Hanoun, M. Hamon, and J. Mallet, “Long-term doxycycline-controlled expression of human tyrosine hydroxylase after direct adenovirus-mediated gene transfer to a rat model of Parkinson's disease,” Proceedings of the National Academy of Sciences of the United States of America, vol. 96, no. 21, pp. 12120–12125, 1999.
[13]
J. A. Wolff, L. J. Fisher, L. Xu et al., “Grafting fibroblasts genetically modified to produce L-dopa in a rat model of Parkinson disease,” Proceedings of the National Academy of Sciences of the United States of America, vol. 86, no. 22, pp. 9011–9014, 1989.
[14]
L. Lu, C. Zhao, Y. Liu et al., “Therapeutic benefit of TH-engineered mesenchymal stem cells for Parkinson's disease,” Brain Research Protocols, vol. 15, no. 1, pp. 46–51, 2005.
[15]
J. R. Forsayeth, J. L. Eberling, L. M. Sanftner et al., “A Dose-Ranging Study of AAV-hAADC therapy in Parkinsonian monkeys,” Molecular Therapy, vol. 14, no. 4, pp. 571–577, 2006.
[16]
M. Sun, G. R. Zhang, L. Kong et al., “Correction of a rat model of Parkinson's disease by coexpression of tyrosine hydroxylase and aromatic amino acid decarboxylase from a helper virus-free herpes simplex virus type 1 vector,” Human Gene Therapy, vol. 14, no. 5, pp. 415–424, 2003.
[17]
M. Sun, L. Kong, X. Wang et al., “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,” Human Gene Therapy, vol. 15, no. 12, pp. 1177–1196, 2004.
[18]
S. Bickel, L. Alvarez, R. Macias et al., “Cognitive and neuropsychiatric effects of subthalamotomy for Parkinson's disease,” Parkinsonism and Related Disorders, vol. 16, no. 8, pp. 535–539, 2010.
[19]
N. K. Patel, P. Heywood, K. O'Sullivan, R. McCarter, S. Love, and S. S. Gill, “Unilateral subthalamotomy in the treatment of Parkinson's disease,” Brain, vol. 126, no. 5, pp. 1136–1145, 2003.
[20]
H. M. Tseng, P. C. Su, H. M. Liu, H. H. Liou, and R. F. Yen, “Bilateral subthalamotomy for advanced Parkinson disease,” Surgical Neurology, vol. 68, supplement 1, pp. S43–S50, 2007.
[21]
J. Luo, M. G. Kaplitt, H. L. Fitzsimons et al., “Subthalamic GAD gene therapy in a Parkinson's disease rat model,” Science, vol. 298, no. 5592, pp. 425–429, 2002.
[22]
M. Y. Mastakov, K. Baer, C. W. Symes, C. B. Leichtlein, R. M. Kotin, and M. J. During, “Immunological aspects of recombinant adeno-associated virus delivery to the mammalian brain,” Journal of Virology, vol. 76, no. 16, pp. 8446–8454, 2002.
[23]
S. U. Kim, I. H. Park, T. H. Kim et al., “Brain transplantation of human neural stem cells transduced with tyrosine hydroxylase and GTP cyclohydrolase 1 provides functional improvement in animal models of Parkinson disease,” Neuropathology, vol. 26, no. 2, pp. 129–140, 2006.
[24]
S. Singh, K. Singh, D. K. Patel et al., “The expression of cyp2d22, an ortholog of human cyp2d6, in mouse striatum and its modulation in 1-methyl 4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinson's disease phenotype and nicotine-mediated neuroprotection,” Rejuvenation Research, vol. 12, no. 3, pp. 185–197, 2009.
[25]
E. Melamed, F. Hefti, V. Bitton, and M. Globus, “Suppression of L-dopa-induced circling in rats with nigral lesions by blockade of central dopa-decarboxylase: implications for mechanism of action of L-dopa in parkinsonism,” Neurology, vol. 34, no. 12, pp. 1566–1570, 1984.
[26]
M. G. Kaplitt, A. D. Kwong, S. P. Kleopoulos, C. V. Mobbs, S. D. Rabkin, and D. W. Pfaff, “Preproenkephalin promoter yields region-specific and long-term expression in adult brain after direct in vivo gene transfer via a defective herpes simplex viral vector,” Proceedings of the National Academy of Sciences of the United States of America, vol. 91, no. 19, pp. 8979–8983, 1994.
[27]
D. Duan, H. Yang, J. Zhang, J. Zhang, and Q. Xu, “Long-term restoration of nigrostriatal system function by implanting GDNF genetically modified fibroblasts in a rat model of Parkinson's disease,” Experimental Brain Research, vol. 161, no. 3, pp. 316–324, 2005.
[28]
M. J. During, K. M. Ryder, and D. D. Spencer, “Hippocampal GABA transporter function in temporal-lobe epilepsy,” Nature, vol. 376, no. 6536, pp. 174–177, 1995.
[29]
D. Young, P. A. Lawlor, P. Leone, M. Dragunow, and M. J. During, “Environmental enrichment inhibits spontaneous apoptosis, prevents seizures and is neuroprotective,” Nature Medicine, vol. 5, no. 4, pp. 448–453, 1999.
[30]
D. L. Martin and K. E. Barke, “Are GAD65 and GAD67 associated with specific pools of GABA in brain?” Perspectives on Developmental Neurobiology, vol. 5, no. 2-3, pp. 119–129, 1998.
[31]
K. G. Lloyd, H. Mohler, Heitz Ph., and G. Bartholini, “Distribution of choline acetyltransferase and glutamate decarboxylase within the substantia nigra and in other brain regions from control and parkinsonian patients,” Journal of Neurochemistry, vol. 25, no. 6, pp. 789–795, 1975.
[32]
M. G. Erlander, N. J. K. Tillakaratne, S. Feldblum, N. Patel, and A. J. Tobin, “Two genes encode distinct glutamate decarboxylases,” Neuron, vol. 7, no. 1, pp. 91–100, 1991.
[33]
P. Gaspar, F. Javoy-Agid, A. Ploska, and Y. Agid, “Regional distribution of neurotransmitter synthesizing enzymes in the basal ganglia of human brain,” Journal of Neurochemistry, vol. 34, no. 2, pp. 278–283, 1980.
[34]
V. Vialou, L. Balasse, S. Dumas, B. Giros, and S. Gautron, “Neurochemical characterization of pathways expressing plasma membrane monoamine transporter in the rat brain,” Neuroscience, vol. 144, no. 2, pp. 616–622, 2007.
[35]
S. J. Kish, A. Rajput, and J. Gilbert, “Elevated γ-aminobutyric acid level in striatal but not extrastriatal brain regions in Parkinson's disease: correlation with striatal dopamine loss,” Annals of Neurology, vol. 20, no. 1, pp. 26–31, 1986.
[36]
J. J. Soghomonian and N. Laprade, “Glutamate decarboxylase (GAD67 and GAD65) gene expression is increased in a subpopulation of neurons in the putamen of Parkinsonian monkeys,” Synapse, vol. 27, pp. 122–132, 1997.
[37]
N. Laprade and J. J. Soghomonian, “Glutamate decarboxylase (GAD65) gene expression is increased by dopamine receptor agonists in a subpopulation of rat striatal neurons,” Molecular Brain Research, vol. 48, no. 2, pp. 333–345, 1997.
[38]
D. T. Stephenson, Q. Li, C. Simmons et al., “Expression of GAD65 and GAD67 immunoreactivity in MPTP-treated monkeys with or without L-DOPA administration,” Neurobiology of Disease, vol. 20, no. 2, pp. 347–359, 2005.
[39]
J. J. Soghomonian, S. Pedneault, G. Audet, and A. Parent, “Increased glutamate decarboxylase mRNA levels in the striatum and pallidum of MPTP-treated primates,” Journal of Neuroscience, vol. 14, no. 10, pp. 6256–6265, 1994.
[40]
J. M. Henderson, “Experimental therapeutics of Parkinson's disease,” Clinical and Experimental Pharmacology and Physiology, vol. 30, no. 11, pp. 841–844, 2003.
