Increasing SPARCL-1 in the hippocampus shown to reverse cognitive decline in a mouse model of Alzheimer's as well as in general age related cognitive decline of other mice. No effect on amyloid plaque, putting another nail in the coffin of that research.
https://doi.org/10.1111/acel.14493
Increased SPARCL-1 is also seen in MS and neuropathic pain so this probably can't be a preventative therapy.