AMPK Activator MK-8722 Improves Spatial Memory Deficit and Alters Metabolome in APP/PS1 AD Mouse Model

Alzheimer's disease (AD) involves early synaptic vulnerability and systemic metabolic dysfunction, yet the impact of peripheral metabolic state on brain function remains unclear. Previous studies indicate a link between AMP-activated protein kinase (AMPK) signaling dysregulation and AD pathophysiology. Here we tested whether systemic treatment of a potent pan-AMPK activator MK-8722 influences cognitive function, synaptic plasticity, and circulating metabolic profiles in APP/PS1 AD model mice at the age of 6-8 months. MK-8722 was well tolerated and activated AMPK in the liver but not in the hippocampus. Our findings revealed that MK-8722 selectively improved AD-associated hippocampal-dependent spatial memory deficits and enhanced dendritic spine maturation in the hippocampus of APP/PS1 mice. In contrast, MK-8722 did not alter hippocampal long-term potentiation (LTP). In-depth analysis of plasma lipidomics and metabolomics revealed coordinated disruptions in glycerophosphatidylcholine species, glutathione cycling, carnitine-dependent fatty acid transport, and the kynurenine pathway in APP/PS1 mice, which were partially normalized by MK-8722 treatment. These findings suggest that peripheral AMPK activation can remodel systemic metabolic networks and improve certain aspects of cognitive and synaptic outcomes in early AD, supporting a model in which metabolic interventions outside the brain influence neuronal resilience.