Peripheral processes that mediate beneficial effects of exercise on the brain remain sparsely explored. Here, researchers find that cathepsin B, a muscle secretory factor, is important for the cognitive and neurogenic benefits of running.
Specifically, cathepsin B enhanced expression of brain-derived neurotrophic factor (BDNF) and doublecortin (DCX) in adult hippocampal progenitor cells through a mechanism dependent on the multifunctional protein P11. In vivo, in cathepsin B-knockout mice, running no longer enhanced adult hippocampal neurogenesis and spatial memory function. In Rhesus monkeys and humans, treadmill exercise elevated cathepsin B in plasma. In human subjects, the changes correlated with fitness and hippocampus-dependent memory function. The authors concluded that cathepsin B is a mediator of effects of exercise on cognition.
Moon HY, Becke A, Berron D, Becker B, Sah N, Benoni G, Janke E, Lubejko ST, Greig NH, Mattison JA, Duzel E and van Praag H: running-Induced Systemic Cathepsin B Secretion is Associated with Memory Function. Cell Metab. [Epub ahead of print, June 21, 2016; doi: 10.1016/j.cmet.2016.05.025].