Metabolomics analysis of bronchoalveolar lavage fluid samples in horses with naturally-occurring asthma and experimentally-induced airway inflammation.

This study investigates the metabolomic profile of bronchoalveolar lavage fluid in both healthy horses and horses with experimentally-induced airway inflammation or naturally-occurring asthma. The findings reveal similar patterns of metabolite changes in horses with experimentally-induced inflammation and those with naturally occurring asthma, suggesting that the model used in this study could be beneficial for future research on equine asthma.

Research Methodology

• The researchers studied three groups of horses: one group was healthy, one had airway inflammation induced experimentally by nebulizing lipopolysaccharide (LPS), and the third group had naturally occurring asthma.
• All the horses underwent clinical and upper airway endoscopic examinations and bronchoalveolar lavage, a procedure to examine the cells present in the lower respiratory tract.
• The fluid collected from the bronchoalveolar lavage process subjected to a metabolic analysis using gas chromatography-mass spectrometry (GC-MS).

Findings

• The metabolic analysis identified 67 peaks corresponding to 53 metabolites in the fluid samples. The metabolites were categorized according to their chemical class, such as organic acids, fatty acids, nucleosides or their derivatives, amino acids, peptides or their derivatives, carbohydrates, and other compounds.
• The patterns of metabolite changes observed in the horses with experimentally-induced airway inflammation were found to be similar to those in the horses with naturally occurring asthma.
• A Fisher’s exact test was used to identify metabolic pathways significantly altered in horses affected by asthma or LPS-induced airway inflammation compared to healthy horses. The most significantly changed pathways were fatty acid biosynthesis, galactose metabolism, and the citrate cycle.

Implications of the Study

• The study suggests that the method of inducing airway inflammation with LPS is an effective model for simulating naturally occurring asthma in horses. This is based on the observed similarity in inflammatory cell profiles (specifically neutrophils) and metabolic alterations in the bronchoalveolar lavage fluid.
• Understanding these metabolic disturbances and their implications could further clarify the pathogenesis of equine asthma, leading potentially to more effective treatments.