Discovery proteomics for the detection of putative markers for eradication of infection in an experimental model of equine septic arthritis using LC-MS/MS.

This research explores the potential biomarkers for the eradication of joint infection in horses. The analysis revealed 26 proteins that were more abundant in the synovial fluid of horses with septic arthritis than in other groups or in the same horses post-infection. This opens a path for further exploration and identification of clinically relevant biomarkers for septic arthritis in horses.

Objective and Methodology

• The goal of this study was to identify possible biomarkers that could signal the eradication of joint infection in horses suffering from septic arthritis. This condition is serious and potentially fatal, and current methods for identifying when the infection has been eradicated are not optimal.
• To discover these possible markers, the researchers performed a proteomics analysis, a large-scale study of proteins, on the synovial fluid and plasma of horses with septic arthritis, horses with non-septic lipopolysaccharide-induced arthritis, and control horses.
• The point at which the infection had been eradicated in the septic horses was determined beforehand.

Findings

• After comparing the spectral intensities between the groups both before and after the eradication of infection, the researchers found 26 proteins that were upregulated (i.e., more abundant) in the synovial fluid of the horses with septic arthritis.
• Interestingly, these 26 proteins were more than ten times as abundant as would be expected based on the difference in cell count alone, suggesting that these proteins could be potential markers for infection eradication.
• Most of these proteins were of cellular origin, and their primary biological functions were in areas like signal transduction, apoptosis – the process of programmed cell death, and ubiquitination – a process where proteins are marked for degradation.
• In the plasma of the horses, no differentially abundant proteins were found.

Significance

• Septic arthritis is a serious and potentially fatal condition in horses, and better ways of determining when an infection has been eradicated are needed. This study’s identification of 26 potentially significant proteins opens a path for future research and the eventual identification of clinically useful biomarkers for this condition.
• The study suggests that the variable abundance of neutrophil- and cell-associated proteins in the synovial fluid could act as potential biomarkers for infection eradication in equine septic arthritis.
• This discovery represents a significant contribution to the ongoing struggle against septic arthritis in horses and could form the basis of further research.