Transition from Winter to Spring Modulates Airway Metabolome in Asthmatic Horses

03 Apr 20264 min read0 viewsJournal Feed

GIST (Key Takeaways)

by Julia Drespling, Steffen Heelemann, Selina Strathmeyer, Heike Kühn, Bianca Schwarz, Lars Mundhenk Equine asthma is a chronic, non-infectious inflammatory disease of the lower airways in horses, classified as mild to moderate (MEA) or severe (SEA). Its pathogenesis is not fully understood and is influenced by environmental and seasonal factors. In this cross-sectional study, seasonal effects on the bronchoalveolar lavage fluid (BALF) metabolome were investigated in asthmatic and non-asthmatic horses.
The metabolome of 230 BALF samples from horses across different seasons, classified as cytologically unremarkable (CUA), MEA, or SEA, was analyzed using proton nuclear magnetic resonance spectroscopy (1H-NMR). Principal component analysis was performed for each season, and metabolite profiles were statistically compared between seasons within each group. Altered metabolites were subjected to pathway enrichment analysis using the FELLA R package.
Asthmatic horses showed significant seasonal changes in metabolite concentrations between warm and cold seasons, whereas only trends were observed in CUA horses. Pathway analysis indicated enrichment of cholesterol metabolism across all groups. The mTOR signaling pathway was only enriched in SEA horses.

Cross-sectional analysis of bronchoalveolar lavage fluid (BALF) metabolomes from horses across seasons, including asthmatic groups (MEA and SEA) and cytologically unremarkable controls (CUA).
A total of 230 BALF samples were analyzed using proton nuclear magnetic resonance spectroscopy (1H-NMR).
Horses were categorized by airway status: CUA, mild–moderate equine asthma (MEA), or severe equine asthma (SEA).

Metabolomic profiles were examined with principal component analysis conducted separately for each season.
Within-group comparisons were performed to identify seasonal differences in metabolite concentrations.
Metabolites showing change were subjected to pathway enrichment analysis using the FELLA R package.

Asthmatic horses exhibited significant seasonal shifts in airway metabolite concentrations when comparing warm versus cold seasons.
In contrast, CUA horses showed only trends rather than significant seasonal changes.
Pathway enrichment revealed cholesterol metabolism as a recurrently implicated pathway across all groups.
The mTOR signaling pathway reached enrichment status exclusively in SEA horses.

Several metabolites were altered during the winter-to-spring transition in asthmatic cohorts, notably valine, taurine, and carnitine.
These shifts were most pronounced in SEA-affected animals.

The winter-to-spring transition appears to modulate the airway metabolome in asthmatic horses, with the strongest signal in SEA cases.
The source notes that effects are more robust in SEA and less evident in CUA, suggesting disease status shapes seasonal metabolomic responses.