1-2-dielaidoylphosphatidylethanolamine and Parkinson-Disease--Secondary

Parkinson's disease is a neurodegenerative disorder characterized by the depletion of dopamine in the caudate putamen. Dopamine replacement with levodopa, a precursor of the neurotransmitter, is presently the most common treatment for this disease. However, in an effort to obtain better therapeutic results, tissue or cells that synthesize catecholamines have been grafted into experimental animals and human patients. In this paper, we present a novel technique to express tyrosine hydroxylase (TH) in the host's own astrocytes. This procedure uses a transgene in which the expression of a TH cDNA is under the control of a glial fibrillary acidic protein (GFAP) promoter, which confers astrocyte-specific expression and also increases its activity in response to brain injury. The method was tested in a rat model of Parkinson's disease produced by lesioning the striatum with 6-hydroxydopamine. Following microinjection of the transgene into the denervated striatum as a DNA-liposome complex, expression of the transgene was detected by RT-PCR and TH protein was observed specifically in astrocytes by using double-labeling immunofluorescence for GFAP and TH coupled with laser confocal microscopy. Efficacy was demonstrated by significant behavioral recovery, as assessed by a decrease in the pharmacologically induced turning behavior generated by the unilateral denervation of the rat striatum. These results suggest this is a valuable technique to express molecules of therapeutic interest in the brain.

Topics: Animals; Astrocytes; beta-Galactosidase; Gene Expression; Gene Transfer Techniques; Genetic Therapy; Glial Fibrillary Acidic Protein; Liposomes; Microinjections; Microscopy, Confocal; Microscopy, Fluorescence; Oxidopamine; Parkinson Disease, Secondary; Phosphatidylethanolamines; Promoter Regions, Genetic; Rats; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tyrosine 3-Monooxygenase

The implantation of cells genetically modified to express tyrosine hydroxylase has been proposed for the treatment of Parkinson's disease. Tyrosine hydroxylase converts tyrosine to L-DOPA and endogenous decarboxylase activity then converts L-DOPA to the neurotransmitter dopamine, which alleviates the symptoms of Parkinson's disease. Immortalized cells have been successfully used as intracerebral vehicles for transgene expression of tyrosine hydroxylase, but the tumorigenic potential of these cells prevents their application in humans. Intracerebral expression of this enzyme has also been achieved using primary cells like skin fibroblasts, but the ameliorating effect on a rat model for Parkinson's disease lasted for only a few weeks. We have found that co-transplantation of cultured myoblasts and myotubes enabled reporter genes to be expressed intracerebrally at high and stable levels. Here we show that the intracerebral transplantation of plasmid-transfected primary muscle cells can substantially reduce for the long-term the asymmetric rotational behaviour in the rat model.

Topics: Animals; Animals, Newborn; Apomorphine; Brain; Cells, Cultured; Dopamine; Drug Carriers; Female; Genetic Therapy; Levodopa; Motor Activity; Muscles; Oxidopamine; Parkinson Disease, Secondary; Phosphatidylethanolamines; Plasmids; Rats; Rats, Sprague-Dawley; Time Factors; Transplantation, Heterotopic; Tyrosine 3-Monooxygenase