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Exercise enhances learning and memory, not only through improved cardiometabolic but also through body-brain interactions mediated by secreted factors. Given the prominent role of skeletal muscle during exercise, muscle-derived factors, myokines, are believed to mediate the exercise-induced cognitive enhancements. Here, we demonstrate that intramuscular Serpina1e is upregulated following exercise in male mice. Systemic delivery of recombinant Serpina1e or intramuscular overexpression of Serpina1e reproduces exercise-induced memory enhancements in sedentary male mice. Conversely, muscle-specific depletion of Serpina1e abolishes hippocampal memory enhancement, indicating a requirement of muscle-derived Serpina1e for these cognitive benefits. Mechanistically, elevated plasma Serpina1e stimulates neurogenesis, brain-derived neurotrophic factor (BDNF) expression, and neurite growth in the hippocampus by crossing the blood-cerebrospinal fluid (CSF) and blood-brain barrier. Our findings identify Serpina1e as a key mediator of skeletal muscle-brain interaction that enables the beneficial effects of exercise on cognitive function. Show less

Myokines and cytokines are signaling proteins released by skeletal muscle cells during exercise that act as messengers, influencing the function of various organs, including the brain. We examined whether a single bout of walking exercise induces distinct changes in plasma myokine and cytokine concentrations in older adults with and without mild cognitive impairment (MCI). In 146 older adults characterized based on the Montreal Cognitive Assessment (MoCA) scores in non-MCI (MoCA score ≥26, n = 55) vs MCI (MoCA score <26, n = 91), we measured cognitive performance by battery, body composition by DXA, and functional performance by 6 min walk test (6MWT) distance. In addition, plasma myokine and cytokine concentrations were assessed before and immediately after 6MWT by MILLIPLEX® Human Myokine Magnetic Bead Panel (HMYOMAG-56K) and Immunology Multiplex Assay (HCYTA-60K-PXBK38) using Luminex® 200™ and MagPix system. Analysis was performed by GLMM to test the effects of group (Non-MCI vs MCI) and walking exercise. The MCI group had worse cognitive performance on trail-making test, stroop color word test (SCWT), phonemic and semantic fluency test, digit span backward, and the Rey auditory verbal learning test (AVLT) delayed memory (all P < 0.02). Body weight, BMI, lean mass, and (visceral) fat mass were comparable between non-MCI and MCI groups. There was a trend toward significantly lower 6MWT distance in the MCI (P = 0.067). We found lower baseline GM-csF concentration (P = 0.006) and a smaller increase in BDNF, FABP-3, and Osteocrin concentration in response to 6MWT in the MCI, even after adjustment for age and 6MWT distance (P < 0.003). Lower BDNF response to exercise was further associated with advancing age and worse cognitive function (MoCA, SCWT) (P < 0.04), but not with changes in lifestyle (habitual physical activity or dietary intake). We observed 6MWT-induced increases for the other myokines (apelin, BDNF, EPO, osteonectin, IL-15, myostatin, FABP-3, FSTL-1, IL-6, FGF-21, and osteocrin), and nearly all cytokines were independent of the group studied (all P < 0.02). A single bout of 6-minute walking exercise elicits a suppressed increase in BDNF, FABP-3, and Osteocrin in individuals with MCI, with a particularly blunted BDNF response in those who are older and more cognitively impaired. Whether disturbances in muscle-brain crosstalk, mediated by suppressed exercise induced BDNF response, contribute to cognitive decline in older adults warrants further investigation. Show less

This study aimed to investigate whether aerobic exercise (AE) and AE combined with whole-body vibration (AE+WBV) exert distinct effects on neurocognitive outcomes and circulating myokines, and to further explore the potential molecular mechanisms underlying exercise-induced neurocognitive changes. A total of 72 postmenopausal women were randomly assigned to an AE, AE+WBV, or control group. At baseline and after the 16-week intervention or control period, both behavioral and event-related potential (ERP) indices were assessed during a visuospatial working memory (WM) task, and serum myokine concentrations of brain-derived neurotrophic factor (BDNF), irisin, insulin-like growth factor-1 (IGF-1), osteocalcin (OC), interleukin-6 (IL-6), and IL-15 were measured. Reaction times, ERP P2 amplitudes, and P2 and P3 latencies remained unchanged postintervention. However, AE significantly improved accuracy rates (ARs) under the two-item WM condition and increased P3 amplitudes under both the two- and four-item conditions. AE+WBV produced broader improvements in both ARs and P3 amplitudes under the two- and four-item conditions. Regarding molecular outcomes, neither intervention affected IL-6 concentrations. In the AE group, BDNF and irisin levels increased significantly postintervention, whereas IL-15 levels decreased. In the AE+WBV group, IGF-1, irisin, and OC levels increased postintervention and IL-15 levels decreased. Changes in neurocognitive performance were significantly associated with BDNF and OC in the AE group, and changes in neurophysiological performance were significantly associated with IGF-1 and irisin in the AE+WBV group. Collectively, these findings suggest that AE and AE+WBV promote distinct myokine profiles and partially improve neurocognitive performance in postmenopausal women, with AE+WBV demonstrating stronger effects, likely mediated by different molecular pathways. Show less

Studies have shown that sarcopenia and its related parameters are associated with cognition. Preclinical evidence suggests that myokines, such as irisin, Brain-Derived Neurotrophic Factor(BDNF), myostatin and Insulin-like Growth Factor-1(IGF-1) might explain this relationship. This study aimed to explore the associations between sarcopenia-related parameters and cognition, and whether myokines influence this association. Exploratory, cross-sectional analysis of data from the Exercise and Nutrition for Healthy AgeiNg (ENHANce,NCT03649698) study. Participants were older adults(≥65 years) with EWGSOP2-defined sarcopenia. Cognitive functioning was assessed by Mini-Mental State Examination(MMSE), Repeatable Battery for the Assessment of Neuropsychological Status(RBANS), Trail Making Test A&B(TMT), Stroop and Maze Test. Sarcopenia-related parameters were measured: Handgrip Strength, Chair Stand Test, appendicular Lean Mass(aLM), Gait Speed (GS) and Short Physical Performance Battery(SPPB). Serum myokines(IGF-1, irisin, myostatin, BDNF) were determined through ELISA. Associations between cognition and sarcopenia-related parameters were analyzed using multivariable regression, adjusting for potential confounders including myokines. Fifty-eight participants were included in this analysis (76.2 ± 6.7 years, ♀:65.5%). After adjustment for age, sex, body mass index, aLM was associated with MMSE(β = 0.193,p = 0.012), RBANS Total(β = 0.196,p = 0.007) and RBANS Attention(β = 0.215,p = 0.002), CST was associated with RBANS Language(β = -0.314,p = 0.030), SPPB was associated with Maze time(β = -0.364,p = 0.004) and TMT-B (β = -0.333,p = 0.013) and GS was associated with TMT-A(β = -0.324,p = 0.045). After adjustments for BDNF& IGF-1, the association between GS and TMT-A became non-significant. Irisin and myostatin did not influence the sarcopenia-cognition associations. Sarcopenia-related parameters are associated with global and specific cognitive domains. BDNF may, partially, explain the association between muscle mass and MMSE. Additional research with larger sample size is needed to confirm these findings. Show less