Premium
Adeno‐associated virus‐mediated gene transfer of human aromatic l ‐amino acid decarboxylase protects mixed striatal primary cultures from l ‐DOPA toxicity
Author(s) -
Doroudchi Mohammad M.,
Liauw Jason,
Heaton Krista,
Zhen Zhu,
Forsayeth John R.
Publication year - 2005
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2005.03048.x
Subject(s) - aromatic l amino acid decarboxylase , dopamine , striatum , pharmacology , toxicity , biology , genetic enhancement , adeno associated virus , chemistry , medicine , biochemistry , endocrinology , vector (molecular biology) , gene , recombinant dna
Although l ‐DOPA is the drug of choice for Parkinson's disease, prolonged l ‐DOPA therapy results in decreased drug effectiveness and the appearance of motor complications. This may be due in part to the progressive loss of the enzyme, aromatic l ‐amino acid decarboxylase (AADC). We have developed an adeno‐associated virus vector (AAV–hAADC) that contains human AADC cDNA under the control of the cytomegalovirus promoter. Infusion of this vector into the striatum of parkinsonian rats and monkeys improves l ‐DOPA responsiveness by improving AADC‐mediated conversion of l ‐DOPA to dopamine. This is now the basis of a proposed therapy for advanced Parkinson's disease. A key concern has been that over‐production of dopamine in striatal neurons could cause dopamine toxicity. To investigate this possibility in a controlled system, mixed striatal primary rat neuronal cultures were prepared. Exposure of cultures to high concentrations of l ‐DOPA induced the following changes: cell death in nigral and striatal neurons, aggregation of neurofilaments and focal axonal swellings, abnormal expression of DARPP‐32, and activation of astroglia and microglial cells. Transduction of cultures with AAV–hAADC resulted in efficient and sustained neuronal expression of the AADC protein and prevented all the l ‐DOPA‐induced toxicities. The protective effects were due primarily to AADC‐dependent conversion of l ‐DOPA to dopamine and an increase in induction of vesicular monoamine transporter resulting in dopamine storage in cultured cells. These results suggest a neuroprotective role for AADC gene transfer against l ‐DOPA toxicity.