PDGF is associated with neuronal and glial alterations of Alzheimer's disease

In the present study we observed that while platelet-derived growth factor (PDGF)-BB is exclusively expressed by neurons in the human brain, PDGF-AA is expressed in neurons and blood vessels. In Alzheimer's disease (AD), antibodies against PDGF-BB (but not PDGF-AA) recognized the neurofibrillary alterations of this disease. The levels of PDGF-BB correlated with the patterns of synaptic loss and sprouting while PDGF-AA immunostaining of the vessels was correlated with glial proliferation. Immunostaining was completely abolished when the antibodies were preincubated with their respective purified recombinant PDGF. Western blot analysis showed that antibodies against PDGF recognized a 31 kDa protein that was mildly increased in AD. These data suggest that PDGF, as well as other neurotrophic factors, play an important role in the mechanisms of neurofibrillary pathology in AD.