A human growth factor that stimulates blood stem cells to proliferate in the bone marrow reverses memory impairment in mice genetically altered to develop Alzheimer’s disease, researchers at the University of South Florida and James A. Haley Hospital found.
The granulocyte-colony stimulating factor (GCSF) significantly reduced levels of the brain-clogging protein beta amyloid deposited in excess in the brains of the Alzheimer’s mice, increased the production of new neurons and promoted nerve cell connections.
The findings are reported online in Neuroscience and are scheduled to appear in the journal’s print edition in August.
GCSF is a blood stem cell growth factor or hormone routinely administered to cancer patients whose blood stem cells and white blood cells have been depleted following chemotherapy or radiation. GCSF stimulates the bone marrow to produce more white blood cells needed to fight infection. It is also used to boost the numbers of stem cells circulating in the blood of donors before the cells are harvested for bone marrow transplants. Advanced clinical trials are now investigating the effectiveness of GCSF to treat stroke, and the compound was safe and well tolerated in early clinical studies of ischemic stroke patients.
“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 USF neuroscientist Juan Sanchez-Ramos, MD, PhD, the study’s lead author. “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 researchers showed that injections under the skin of filgrastim (Neupogen®) — one of three commercially available GCSF compounds — mobilized blood stem cells in the bone marrow and neural stem cells within the brain and both of these actions led to improved memory and learning behavior in the Alzheimer’s mice. “The beauty in this less invasive approach is that it obviates the need for neurosurgery to transplant stem cells into the brain,” Dr. Sanchez-Ramos said.