"GCSF has been used and studied clinically for a long time, but we're the first group to apply it to Alzheimer's disease," said lead author Juan Sanchez-Ramos of the University of South Florida. "This growth factor could potentially provide a powerful new therapy for Alzheimer's disease— one that may actually reverse disease, not just alleviate symptoms like currently available drugs."
The GCSF also enhanced the production of new neurons in the hippocampus, the area of the brain intimately involved in memory ...
The research team injected 52 mice, half of whom were bred to develop Alzheime's-like symptoms and half of whom were normal, with filgrastim, a commonly used GCSF, or saline (control). After the series of injections, the GCSF-injected Alzheimer's mice performed just like normal mice on memory tests, while the saline-injected Alzheimer's mice still showed significant deficits. The normal mice showed no improvement in memory function after the GCSF injections.
Equally interesting were the results when the researchers looked at the brains of the mice: Alzheimer's mice treated with GCSF showed markedly fewer beta amyloid plaques than did their counterparts who were not treated with the growth factor. Amyloid compounds are thought to be largely responsible for the impairment in memory function in Alzheimer's patients. The GCSF-treated group showed a 36-42% reduction in size and spread of the plaques.
The GCSF appeared to work in a couple of different ways. For one, it prompted microglia (the brain's toxin attackers) from within and outside the brain to band together to break down the plaques. The GCSF also enhanced the production of new neurons in the hippocampus, the area of the brain intimately involved in memory, and the one that appears to be the most devastated in the development of Alzheimer's.
The next step will be to extend the findings to clinical trials, which are currently being funded by the Alzheimer's Drug Discovery Foundation and will also be run at USF. Ashok Raj, one of the researchers heading the upcoming human study, underlines that the "concept of using GCSF to harness bone marrow-derived cells for Alzheimer's therapy is exciting and the findings in mice are promising, but we still need to prove that this works in humans."