Serial-omics characterization of equine urine.
Authors: Yuan Min, Breitkopf Susanne B, Asara John M
Journal: PloS one
Summary
# Editorial Summary: Serial-omics characterization of equine urine Urine represents an accessible biological matrix for monitoring equine health, yet its molecular composition remained poorly characterised until this 2017 study. Min and colleagues employed a streamlined liquid-liquid extraction protocol utilising methyl tert-butyl ether and methanol to fractionate a single 333 µL mid-stream urine sample into three distinct layers, which were then analysed by LC-MS/MS to simultaneously profile proteins, polar metabolites and lipids from one aliquot. The analysis identified 46 proteins (predominantly kidney-associated and structural proteins), 474 polar metabolites (with notable representation of urea cycle intermediates, ammonia recycling pathways and amino acid metabolism reflecting the mare's forage-based diet), and only 10 lipid species. This comprehensive baseline characterisation of a healthy adult mare's urinary proteome and metabolome establishes a reference dataset that practitioners can use to interpret deviations associated with systemic disease, metabolic dysfunction or performance concerns, whilst also providing a framework for detecting prohibited substances in competition horses. Given the non-invasive nature of urine collection and the discriminatory power of multi-omics profiling, these methods offer considerable potential for longitudinal health monitoring and early disease detection in clinical and performance settings.
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Practical Takeaways
- •Equine urine can serve as a non-invasive biomarker source for monitoring health status, disease progression, and detecting drug use in working horses
- •This baseline healthy urine profile provides a reference standard for identifying abnormal metabolic or kidney function changes in individual horses
- •Minimal urine volume (333 μL) required makes serial monitoring practical for field collection and clinical tracking
Key Findings
- •Serial-omics analysis of equine urine identified 46 proteins, 474 polar metabolites, and 10 lipid molecules from a single 333 μL sample using LC-MS/MS
- •Urine proteins were predominantly related to normal kidney function, structural and circulatory proteins
- •Metabolites were primarily associated with urea cycle, ammonia recycling, and amino acid pathways, plus plant diet-specific molecules
- •Complete mass spectrometry-based omics profile established as baseline reference for healthy mare urine composition