Here is an interim report that I found on MJFF. I couldn't find anything more recent either on MJFF or PubMed.

INTERIM PROGRESS REPORT



Professor Waszczak reported that intranasal administration of GDNF has a neuroprotective efficacy in a pre-clinical model of Parkinson’s disease. Neuroprotection is also achieved by stereotaxic injection of gene vectors expression GDNF into the striatum. Other studies show that 125I-GDNF undergoes receptor mediated retrograde transport from the striatum to the midbrain dopaminergic neuron cell bodies. To distinguish gene-derived from endogenous GDNF, we used a gene vector expressing GDNF with an epitope tag. This gene vector was intranasally administered to test whether the intranasal (gene-derived) GDNF would appear within the midbrain dopaminergic neuron cell bodies.

Significant technical issues, such as delivery losses due to the “sticky” nature of gene vector, prevented reproducible adequate transfection following intranasal administration. While a sensitive histological/immunohistochemical procedure for visualizing trace GDNFflag in intracellular vesicles was developed, further studies are required to properly test whether intranasal, gene-derived, GDNF can make direct contact with receptors expressed by midbrain dopaminergic neurons.

April 2012