Expression of extracellular matrix metalloproteinase inducer and matrix metalloproteinase-2 and -9 in horses with chronic airway inflammation.

This research explores the possible role of a protein, extracellular matrix metalloproteinase inducer (EMMPRIN), in causing chronic inflamed lungs in horses. The study found that levels of EMMPRIN were higher in horses with respiratory distress and seemed to coincide with increased expression of other compounds (MMP-2 and -9), suggesting that EMMPRIN might contribute to asthma-like conditions in horses.

Objective and Subject Details

• The study aimed to investigate whether extracellular matrix metalloproteinase inducer (EMMPRIN) could be detected in horse lungs and if its presence correlated with matrix metalloproteinase (MMP)-2 and -9 expression in the fluid from the bronchoalveolar lavage (BALF) of horses with lower airway inflammation (LAI).
• The animals included in the study were 29 horses showing signs of chronic respiratory tract disease. These horses were classified into two categories: those with LAI (17 horses) and those with LAI that also had respiratory distress (RDLAI, 12 horses). There were also 15 control horses who didn’t exhibit respiratory distress.

Procedures

• BALF, tracheal aspirate, and blood samples were collected from all horses. The expression of EMMPRIN was then identified from the BALF cells and red blood cells (RBCs) using a western blotting method.
• The activities of MMP-2 and -9, which are enzymes involved in the breakdown of extracellular matrix in normal physiological processes and disease processes, were determined through zymography, a type of electrophoresis for detecting these enzymes in the samples.

Results

• The research unveiled that EMMPRIN protein could be identified in the BALF cells of all the horses. Furthermore, the highest levels of EMMPRIN were found in the RDLAI group.
• A correlation was found between the expression of EMMPRIN protein and MMP-2 and -9 protein expression, gelatinolytic activity of MMP-9, and neutrophilia, a condition characterized by high levels of neutrophils that often indicates infection or inflammation, in airways.

Conclusion and Clinical Relevance

• The results suggest that EMMPRIN could be involved in the pathophysiological processes that lead to asthmatic conditions in horses. This discovery indicates that EMMPRIN expression could contribute to the development of chronic lung inflammation, similar to asthma, in these animals.
• However, more research with horses and other species is necessary to gain a deeper understanding of how EMMPRIN expression is regulated in asthmatic lungs and its exact role in such conditions.