Exercise-Associated Signaling Against CNS Aging and Alzheimer's Disease

ABSTRACT Skeletal muscle has recently arisen as a novel regulators of Central Nervous System (CNS) function and aging, secreting bioactive molecules known as myokines with proteostasis and metabolism-modifying functions in targeted tissues, including the CNS. Myokine secretion is heavily modified by exercise, suggesting that myokine signaling in the periphery may underlie the well documented geroprotective benefits of exercise on the brain. The following studies address muscle proteostasis, a pathway highly activated during exercise, as a potential new regulator of the neurocognitive benefits of exercise. We have recently generated a novel transgenic mouse with enhanced muscle proteostasis via moderate overexpression of Transcription Factor E-B (TFEB), a powerful master regulator of cellular clearance and proteostasis. We have discovered that the resulting enhanced skeletal muscle proteostasis function can significantly ameliorate proteotoxicity in the aging CNS and also improve cognition and memory in aging mice. Enhancing muscle proteostasis also reduced neuroinflammation and accumulation of AD-associated pathological hallmarks in plaque based and a tau- based models of AD. We have also identified previously unreported alterations in the transcriptome of skeletal muscle from patients with AD, as well as potential unique populations of skeletal muscle factors that may be driving these CNS benefits. In this project, we will determine if enhanced skeletal muscle proteostasis promotes neuroprotection against AD-associated phenotypes, and using powerful transfer learning and computational modeling approaches, identify exercise-associated circulating factors as new therapeutic interventions for the preservation of CNS function during AD.