Abstract
Objective—To examine the effects of in vitro exposure to solutions of autologous horse blood (AHB) and autologous horse serum (AHS) on expressions of selected cytokine genes in equine primary bronchial epithelial cell (BEC) cultures and to contrast these responses to those induced in BEC cultures by endotoxin and hay dust.
Sample—BEC cultures established from bronchi of 6 healthy horses.
Procedures—5-day-old BEC cultures were treated with PBS solution, AHB (2 concentrations), AHS, hay dust solution, and lipopolysaccharide solution for 24 hours. Gene expressions of interleukin (IL)-8, IL-1β, chemokine (C-X-C motif) ligand 2 (CXCL2), and glyceralde-hyde-3-phosphate dehydrogenase were subsequently measured with a kinetic PCR assay.
Results—With the exception of AHS, all treatments of the BECs resulted in upregulation of each target gene expression relative to its expression in cultures exposed to PBS solution. Treatment with AHB induced a dose-dependent increase of each target gene, with IL-1β expression increasing the most (> 1,200-fold increase). Lipopolysaccharide and hay dust solution treatments each resulted in 20-fold increases in IL-8 and IL-1β gene expressions. Lipopolysaccharide and hay dust solution treatments also resulted in a 7- and 8-fold increase in CXCL2 gene expression, respectively. The increases in IL-8 and CXCL2 gene expressions following treatment with the higher concentration of blood were equivalent to those associated with hay dust solution or lipopolysaccharide.
Conclusions and Clinical Relevance—Results suggested that chemokine expression by cultured equine BECs following exposure to pulmonary hemorrhage conditions may contribute to the development of inflammatory airway disease in horses.
