Loss-of-function mutations in progranulin (GRN) are a major genetic cause of frontotemporal
dementia (FTD), possibly due to loss of progranulin's neurotrophic and anti-inflammatory
effects. Progranulin promotes neuronal growth and protects against excitotoxicity and other
forms of injury. It is unclear if these neurotrophic effects are mediated through cellular
signaling or through promotion of lysosomal function. Progranulin is a secreted proprotein
that may activate neurotrophic signaling through cell-surface receptors. However …