PDGF IS ASSOCIATED WITH NEURONAL AND GLIAL ALTERATIONS OF ALZHEIMERS-DISEASE

In the present study we observed that while platelet-derived growth fa ctor (PDGF)-BB is exclusively expressed by neurons in the human brain, PDGF-AA is expressed in neurons and blood vessels. In Alzheimer's dis ease (AD), antibodies against PDGF-BB (but not PDGF-AA) recognized the neurofibrillary alterations of this disease. The levels of PDGF-BB co rrelated with the patterns of synaptic loss and sprouting while PDGF-A A immunostaining of the vessels was correlated with glial proliferatio n. Immunostaining was completely abolished when the antibodies were pr eincubated with their respective purified recombinant PDGF. Western bl ot analysis showed that antibodies against PDGF recognized a 31 kDa pr otein that was mildly increased in AD. These data suggest that PDGF, a s well as other neurotrophic factors, play an important role in the me chanisms of neurofibrillary pathology in AD.