Circulating mitochondrial‐derived microproteins at rest and in response to an acute bout of endurance exercise in individuals with cerebral palsy

Regular exercise using assistive movement devices, such as running frames, has emerged as a promising strategy to improve cardiorespiratory fitness in individuals with cerebral palsy (CP). However, the molecular pathways underlying these adaptations remain poorly understood. Here, we examined a novel class of signalling molecules, mitochondrial-derived microproteins (MDPs), and assessed whether individuals with CP exhibit altered circulating levels compared with typically developing (TD) individuals at rest and following an acute bout of endurance exercise. Three groups were included: TD adults (31 ± 6 years), TD adolescents (16 ± 1 years) and adults with CP (25 ± 6 years). Individuals with CP were classified as Gross Motor Function Classification System (GMFCS) levels II-IV and had at least 3 months of frame running experience. Habitual physical activity, ultrasound-derived muscle thickness, and peak oxygen uptake were assessed. The exercise session consisted of 45 min of frame running for individuals with CP and conventional running for TD participants. Blood samples were obtained before and 1 h after exercise, and plasma MDP concentrations were measured using in-house enzyme-linked immunosorbent assay. Adults with CP had reduced muscle mass and maximal oxygen uptake compared to TD individuals. Despite this, they exhibited basal circulating levels of MDPs, including humanin, MOTS-c and SHMOOSE, comparable to TD adults and adolescents, with no associations with CP subtype or motor impairment severity. Following exercise, circulating MDPs showed no or only modest changes across groups, with no differences between CP and TD individuals. Overall, these findings suggest preserved mitochondrial-derived signalling via MDPs in individuals with CP.