Modeling the pasture-associated severe equine asthma bronchoalveolar lavage fluid proteome identifies molecular events mediating neutrophilic airway inflammation.

The research study is focused on understanding the molecular mechanisms behind pasture-associated severe equine asthma to shed light on neutrophilic airway inflammation. The authors applied proteomic analysis to bronchoalveolar lavage fluid from asthmatic and non-asthmatic horses and found that certain proteins associated with increased neutrophil activity were more prevalent in the asthmatic subjects.

Objective and Hypothesis

• The research article revolves around studying pasture-associated severe equine asthma, a respiratory disease occurring in warm seasons causing breathing difficulties in horses due to airway obstruction and chronic inflammation.
• The study authors proposed a hypothesis that the proteins found in the bronchoalveolar lavage fluid (BALF) of asthmatic horses play a significant role in the neutrophil activities, ultimately contributing to the overall airway inflammation.

Method of Data Collection

• The researchers used shotgun proteomics to identify unique proteins present in the BALF of the affected horses and healthy counterparts, ultimately cataloging 1,003 individual proteins.
• The team then applied manual biocuration to determine the net effects of these proteins on various neutrophil functions. This predictive model was designed to understand changes in these functions related to asthma.

Significant Findings

• A total of 417 proteins were unique to the affected horses, while 472 proteins were only found in the control group; only 114 proteins were shared by both groups.
• It was noted that the proteins associated with the processes increasing neutrophil activities (migration, chemotaxis, spreading, transmigration, infiltration) were over-represented in asthmatic horses.
• In contrast, proteins promoting neutrophil activation, adhesion, phagocytosis, respiratory burst, and apoptosis (which arguably shorten neutrophil lifespan) were found to have less representation in the BALF of asthmatic horses.

Impact of these findings

• The model and results supported the initial hypothesis, indicating that there are indeed differences in the protein activities impacting neutrophil functions contributing to airway inflammation in horses with asthma when compared to healthy horses.
• This research illustrates the importance of using systems modeling for understanding the roles of various proteins in disease processes, enabling a more nuanced approach to devising potential treatment options.