Adeno-associated virus-mediated delivery of glial cell line-derived neurotrophic factor protects motor neuron-like cells from apoptosis

Motor neuron disorders including amyotrophic lateral sclerosis may benefit from the induction of neurotrophic factors such as glial cell line-derived neurotrophic factor (GDNF) that are known to be trophic and protective for motor neurons. However, the application of such factors is limited by an in ability to successfully target their expression in the nervous system. In t his study we investigate the potential of using adeno-associated virus (AAV ) as a vector for gene delivery into motor neuron-like cells. In initial ex periments on the motor neuron cell line NSC-19 using a recombinant AAV vect or expressing the reporter gene beta -galactosidase (AAV-LacZ), we successf ully demonstrate the utility of AAV for gene transfer. In addition, a recom binant AAV vector expressing GDNF was shown to express and secrete high lev els of the neurotrophic factor into the surrounding media of NSC-19 infecte d cells. Finally, the AAV-GDNF vector is demonstrated to act in a neuroprot ective fashion. Withdrawal of trophic support from NSC-19 cells through ser um deprivation results in a subsequent increase in the number of cells ente ring apoptosis. However, the percentage of apoptotic cells are significantl y reduced in cells infected with the AAV-GDNF vector, as compared to AAV-La cZ or uninfected controls. This work demonstrates the potential of using AA V as a vector in motor neuron-like cells and should prove important in devi sing future gene therapy strategies for the treatment of in vivo motor neur on disorders.