Exercise-specific plasma proteomic signatures in racehorses: Candidates for training adaptation and peak load monitoring.
Authors: Grzędzicka Jowita, Świderska Bianka, Sitkiewicz Ewa, Dąbrowska Izabela, Witkowska-Piłaszewicz Olga
Journal: Equine veterinary journal
Summary
# Exercise-Specific Plasma Proteomic Signatures in Racehorses Racehorses experience substantial molecular remodelling during training and competition, yet conventional blood biomarkers fail to capture the full complexity of these adaptive responses. To address this gap, researchers analysed plasma samples from 49 Arabian and Thoroughbred racehorses across three distinct training phases using high-resolution mass spectrometry proteomics, collecting 314 samples at rest, immediately post-exercise and during recovery to build a longitudinal picture of physiological adaptation. The proteomic landscape shifted markedly between phases: early training (T1) triggered broad inflammatory and antioxidant activation (including S100A8/A9 and superoxide dismutase), mid-season conditioning (T2) refined this response with cytoskeletal and redox-regulating proteins (thymosin β4, glutathione S-transferase), whilst racing provoked the strongest response with over 100 upregulated proteins spanning energy metabolism, oxidative defence and structural adaptation. Five proteins—S100A8, thymosin β4, prothymosin-α, cofilin-1 and lipocalins—showed consistent modulation across all phases, positioning them as robust candidates for tracking training adaptation and detecting overload risk. For practitioners, these findings suggest that targeted plasma proteomic profiling could move beyond crude fitness indicators towards objective, sensitive monitoring of training status and early warning of maladaptation in equine athletes, though further validation in larger, genetically diverse cohorts using practical assay formats will be essential before clinical application.
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Practical Takeaways
- •Plasma protein panels may enable objective monitoring of training adaptation and identification of overtraining syndrome in racehorses before performance decline occurs
- •Different training phases produce distinct proteomic signatures, suggesting that biomarker interpretation should account for training phase rather than using single reference values
- •These candidate biomarkers could support evidence-based decisions about training load adjustment, recovery protocols and readiness for competition in racing programs
Key Findings
- •Proteomic signatures differ across training phases: T1 shows broad inflammatory and antioxidant activation, T2 displays refined redox regulation, and racing phase elicits over 100 up-regulated proteins linked to energy metabolism and oxidative defense
- •S100A8, thymosin β4, prothymosin-α, cofilin-1 and lipocalins are consistently modulated across all training phases, demonstrating biomarker potential for monitoring training status
- •Racing phase produces the strongest proteomic response with significant up-regulation of energy metabolism, oxidative defense and cytoskeletal adaptation proteins compared to training phases