12509 Identification Of Novel Exercise Training-induced Circulating Proteins: Hemostatic, Apoptotic, And Key Neuronal Factors

Abstract Disclosure: A. Shalit: None. M. Vamvini: None. P. Nigro: None. L.K. Simpson: None. H. Pan: None. J.M. Dreyfuss: None. L.J. Goodyear: Grant Recipient; Self; Daiichi Sankyo. R.J. Middelbeek: None. Exercise training induces a plethora of health benefits including improved glucose homeostasis, decreased cardiovascular disease, and improved cognitive function. An emerging concept is that many of these beneficial effects of exercise are mediated through the secretion of humoral factors into the blood. Identification of these exercise-regulated factors hold promise for novel treatments for disease. Here, we performed proteomic analysis to discover novel circulating factors in response to endurance exercise training in human participants. Given that nutritional status can affect the circulating proteome, another aim was to determine if proteomic adaptations to exercise training have similar effects under both fasted and random-fed conditions. Sedentary normoglycemic participants (3M/5F, age 22-41y) performed a supervised 10-week exercise training program, which by week 4 was 4x60 min exercise at 65-70% V̇O2peak. Fasted and random-sampling morning blood draws were collected pre-training and between 24-72 hours following the final training session. Proteomic detection was by SOMAscan. Exercise training significantly improved V̇O2peak by 17% (p=0.003). Out of 1,310 detected proteins, exercise training significantly changed 293 proteins in the fasted state and 360 proteins in the random-sampling state (p<0.05). Integration showed that 172 proteins were changed under both nutritional conditions (123 upregulated and 49 downregulated). Gene Set Enrichment Analysis (GSEA) of the commonly upregulated proteins showed that training resulted in enrichment in neuronal, hemostatic, and apoptotic pathways, whereas the downregulated proteins were enriched in neuronal and extracellular matrix processes. Since neuronal pathways were identified in both up and downregulated proteins, we focused our analysis there, identifying 31 upregulated and 4 downregulated neuronally-associated proteins. Importantly, exercise training reduced levels of CDK5, a protein that is hyperactivated in neurodegeneration and Alzheimer's disease. Moreover, GSTP1, a direct inhibitor of CDK5, along with downstream proteins inhibited by CDK5 (RAC1, STUB1, 14-3-3ε/YWHAE, HSP90AA1, CFL1), were significantly increased following exercise training.In conclusion, exercise training regulates circulating factors involved in neuronal, hemostatic, apoptotic, and extracellular matrix pathways, with these effects being independent of nutritional status. Our finding of exercise training-induced decreases in multiple proteins of the CDK5 pathway, a pathway whose downregulation is associated with neuroprotection, identify CDK5 as a novel and potentially important mediator of the beneficial effects of exercise training on cognitive function. Presentation: 6/1/2024