Granulocyte colony-stimulating factor (G-CSF) is a hematopoietic growth factor that stimulates the proliferation of hematopoietic stem cells and also promotes their release from the bone marrow into the blood. G-CSF has been reported to stimulate the regeneration of nonhematopoietic tissues following damage, such as skeletal muscle, heart, and neurons. Tsai et al. found that injected G-CSF improved neurological function in two mouse models of Alzheimer's disease (AD). The AD mice performed better in the Morris water maze test after injection with G-CSF. The neuronal cell death and damage associated with AD involves the formation of plaques containing high concentrations of amyloid β protein (Aβ). Although the concentration of Aβ in the brains was unchanged by G-CSF treatment, there was increased cell proliferation in the areas surrounding the plaques and increased acetylcholine, the neurotransmitter that is decreased in AD brains due to loss of cholinergic neurons. Costaining of the proliferating cells suggested that they were derived from the hematopoietic stem cells. Thus, G-CSF, which is already used clinically to treat neutropenia, may provide additional options for ameliorating the symptoms of AD.
K.-J. Tsai, Y.-C. Tsai, C.-K. J. Shen, G-SCF rescues the memory impairment of animal models of Alzheimer's disease. J. Exp. Med. 204, 1273-1280 (2007). [PubMed]