DEREGULATION OF CIRCULATING MICRORNAS AFTER REPETITIVE HEAD IMPACTS IN ELITE FEMALE FOOTBALL PLAYERS

Exposure to repetitive head impacts (RHI) can contribute to brain alterations at multiple levels. In this study, we explored the molecular processes associated with nonconcussive RHI in elite female football players. We aimed to identify differentially expressed circulating microRNAs in response to repetitive low-intensity headers.
Elite female football players performed training without heading the ball and training including heading. The levels of microRNAs in plasma were determined at 4 timepoints: before training, 1 h, 24 h, and 48 h after each training session.
Repetitive headers led to deregulation of 5 specific microRNAs that targeted 711 genes associated with signalling in the central nervous system. Analysis of training without headers identified 4 deregulated microRNAs showing 547 interacting genes associated with growth factor signalling, regulation of cell cycle, gene expression and apoptosis. Furthermore, pathway enrichment analysis identified 145 significantly enriched pathways after heading and 124 enriched pathways after exercise without RHI. Comparison of molecular pathways revealed that head impact exposure is specifically associated with signalling events linked to development of nervous system, neurogenesis, memory and learning, while the training without RHI significantly associates with differentiation of neurons and development of dendrites.
RHIs induce specific changes in peripheral microRNAs associated with unique molecular signalling that differentiates the physiological response to RHI from exercise. Our findings are potentially relevant for biomarker research and risk assessment of developing neurocognitive/neurodegenerative disorders due to RHI exposure in later life.
This work was supported by Research grants: APP0706, APVV-24-0530, APVV-22-0470, APVV-22-0613, APVV-24-0026, VEGA 2/0086/23, VEGA 2/0070/26.