Gene therapeutic approaches to the treatment of Parkinson's disease

Gazing into the future: Parkinson's disease gene therapeutics to modify natural history

PD gene therapy clinical trials have primarily focused on increasing the production of dopamine (DA) through supplemental amino acid decarboxylase (AADC) expression, neurotrophic support for surviving dopaminergic neurons (DAN) or altering brain circuitry to compensate for DA neuron loss. The future of PD gene therapy will depend upon resolving a number of important issues that are discussed in this special issue. Of particular importance is the identification of novel targets that are amenable to early intervention prior to the substantial loss of DAN. However, for the most part the etiopathogenesis of PD is unknown making early intervention a challenge and the development of early biomarker diagnostics imperative.

Novel gene therapeutic strategies for neurodegenerative diseases

The convergent pathobiologic model of Parkinson's disease stipulates that disparate insults initiate a disease process that obligately share a common pathway leading to cell death. A combinatorial treatment which targets various steps in this pathway is likely to be the most successful therapeutic strategy. As advances are made in the field of neuroimaging and pharmacogenomics, early detection of sporadic PD will become a reality. Early intervention will likely spare more dopaminergic neurons and extend the quality of life for the patient. Continued advancements in the fields of pharmacology, neurosurgery, and gene therapy will strengthen the armamentarium available for the treatment of PD patients.

Convergent pathobiologic model of Parkinson's disease

The etiology of Parkinson's disease (PD) has yet to be delineated. Human genetic studies as well as neurotoxicant and transgenic animal models of PD suggest that multiple events trigger the initiation of this progressive age-related neurodegenerative disorder. In addition, we propose that despite disparate disease triggers a convergent pathobiologic pathway exists leading to cell death. The common pathway model posits that both familial and sporadic forms of Parkinson's disease obligately share a common pathophysiological substrate. Herein we discuss the evidence for a common pathway model of Parkinson's disease through a review of synuclein transgenic models and outline an approach for the identification of shared therapeutic targets. We end with a discussion of a potential alternative therapy for Parkinson's disease.