Nasal secretory fluid
proteomes (NSPs) can provide valuable information about the physiopathology and prognosis of
respiratory tract diseases. This study aimed to determine changes in NSP by using proteomics in calves treated with
lipopolysaccharide (LPS) or LPS +
choline. Healthy calves (n = 10) were treated with LPS (2 μg/kg/iv). Five minutes after LPS injection, the calves received a second iv injection with saline (n = 5, LPS + saline group) or saline containing 1 mg/kg
choline (n = 5, LPS +
choline group). Nasal secretions were collected before (baseline), at 1 h and 24 h after the treatments and analysed using label-free liquid chromatography-tandem mass spectrometry (LCMS/MS). Differentially expressed
proteins (>1.2-fold-change) were identified at the different time points in each group. A total of 52
proteins were up- and 46 were downregulated at 1 h and 24 h in the LPS + saline group. The upregulated
proteins that showed the highest changes after LPS administration were small
ubiquitin-related modifier-3 (SUMO3) and
glutathione peroxidase-1 (GPX1), whereas the most downregulated
protein was E3
ubiquitin-protein ligase (TRIM17). Treatment with
choline reduced the number of upregulated (32
proteins) and downregulated
proteins (33
proteins) in the NSPs induced by LPS. It can be concluded that the
proteome composition of nasal fluid in calves changes after LPS, reflecting different pathways, such as the activation of the immunological response, oxidative stress,
ubiquitin pathway, and SUMOylation.
Choline treatment alters the NSP response to LPS.