GDNF

Class

neurotrophic factor (recombinant protein)

GDNF, or glial cell line-derived neurotrophic factor, is a secreted protein that supports the survival and function of specific neuron populations, most notably the dopamine-producing neurons of the midbrain and motor neurons of the spinal cord. It acts as a growth-factor-like signal that neurons depend on for maintenance and repair, working through a dedicated receptor complex on the cell surface. The therapeutic rationale for supplying additional GDNF rests on the idea that neurodegenerative diseases involve a progressive loss of these vulnerable neurons, and that reinforcing their survival signaling might slow or partially reverse decline rather than only masking symptoms. Because GDNF is a large protein that does not cross the blood-brain barrier or diffuse efficiently through brain tissue, delivering it as a conventional injected drug is impractical for chronic neurological disease; this has motivated approaches such as gene therapy, in which a viral vector carrying the GDNF gene is delivered directly to affected brain regions so that local cells produce the protein continuously. This mechanism is discussed primarily in the context of Parkinson's disease, where dopaminergic neuron loss in the striatum drives motor symptoms, and to a lesser extent in motor neuron disease.