GM-CSF is a circulating cytokine that produces many different effects, and operates in both pro-inflammatory and anti-inflammatory contexts. Confusingly, one finds both delivery and inhibition of GM-CSF under development as therapies in different contexts. Here, researchers discuss its ability to improve memory function in aged mice, possibly by suppressing age-related inflammation in the brain, to be balanced against the point that raised GM-CSF is a feature of many inflammatory conditions. Further, it is worth considering that exercise, or indeed any form of improved blood flow to the brain, improves memory function at all ages. When looking at any new treatment, it makes sense to compare the magnitude of the effect with what can be achieved just by physical exercise. To be interesting, it should be significantly larger, a goal that remains a challenge in many areas of development.
A new study shows that a potential treatment for Alzheimer's disease may also improve cognitive function in people with Down syndrome. The drug sargramostim (recombinant GM-CSF, which stands for granulocyte-macrophage colony-stimulating factor) is the first to show memory improvement in Alzheimer's patients in a phase II clinical trial. GM-CSF is a normal human protein that is safe and well-tolerated with over 30 years of FDA-approved use for other disorders.
Researchers discovered that treatment with GM-CSF, which has pro-inflammatory, anti-inflammatory, and immune regulatory properties, reverses learning and memory deficits, the loss of certain nerve cells, and other abnormalities in the brain in a mouse model of Down syndrome and also improves cognition in normal aging mice.
The human version of GM-CSF/sargramostim has already been shown to be effective in improving cognition in people with mild-to-moderate Alzheimer's disease and in cancer patients. The findings support the hypothesis that GM-CSF/sargramostim may promote neuronal recovery from injury or from neurological disease through multiple mechanisms, some of which evidently enhance cognitive function.