Scrapie-induced neuron loss is reduced by treatment with basic fibroblast growth factor.

Neuron loss can be a prominent feature of the pathology of transmissible spongiform encephalopathies (TSEs); recent evidence indicates that this loss occurs through apoptosis. Growth factor treatment of other neurodegenerative diseases has been shown to protect neurons destined for apoptosis, and several types of experimental retinopathy have been successfully treated with basic fibroblast growth factor (bFGF). In a murine scrapie model which develops a severe loss of photoreceptors, we administered a single intravitreal injection of bFGF four-fifths of the way through the disease process; this doubled the number of photoreceptors surviving for up to 5 weeks, i.e. to the terminal stages of the disease. This is the first time that a potential late-stage therapy for the TSEs has been demonstrated.