Application across species of a one health approach to liquid sample handling for respiratory based -omics analysis.

The research is about developing a method to collect and analyze tracheal wash (TW) samples in horses. This is used to study airway inflammation, like equine asthma. The goal is to establish a useful method that can be applicable across species and provide valuable molecular data for studying respiratory diseases.

Background

• The study begins by noting that airway inflammation, especially equine asthma, is common in horses.
• At present, the standard procedure for assessing lower airway inflammation involves cytological analysis of airway derived samples.
• These samples can either be procured via tracheal wash (TW), or through bronchoalveolar lavage (BAL) where fluid from the lower respiratory tract is collected.
• Though bronchoalveolar lavage fluid (BALF) cytology has better diagnostic value for equine asthma than TW cytology, the process is invasive and not suitable for routine checks.
• Recent developments in sample processing and collection technologies, however, have made it feasible to apply a wider range of tests on TW samples.

Method and Aim

• The authors aimed to establish a robust process to extract macrophages, protein, and RNA for molecular characterization of the equine tracheal secretions, expecting richer data for both transcriptomic and proteomic analysis.
• Similar practices have already been applied on equivalent samples in humans, specifically on induced sputum samples.
• Sputum provides a readily available source of airway biofluid enriched in proteins, and changes in protein expression could open up new mechanisms in the pathogenesis of respiratory diseases like asthma and chronic obstructive pulmonary disease.
• The study also aimed to validate the applicability of this sample handling on bronchoalveolar lavage fluid samples from rodents and human pediatric studies.

Findings and Conclusion

• The researchers found that the tracheal wash samples provided useful RNA and proteins for downstream transcriptomic and proteomic analysis, thus proving their hypothesis that the TW samples are a rich source of airway cells and molecular data.
• The process was successfully applied to BALF samples for rodent and human research, thereby confirming the cross-species applicability of the method.
• This research builds a methodological foundation for future transcriptomic or proteomic studies on equine lower respiratory tract secretions and human and rodent BALF samples.