Expression of genes associated with inflammation induced by ex vivo exposure to lipopolysaccharide in peripheral blood leukocytes from horses with gastrointestinal disease.

The research article involves a study on how inflammatory genes in white blood cells (leukocytes) from horses with gastrointestinal disease respond to exposure to lipopolysaccharide (LPS). The researchers found that these leukocytes’ gene expression changed according to pathogenesis and prognosis of the disease, and there was no indication of decreased leukocyte response to LPS.

Study Objective and Methods

• The study’s goal was to see how exposure to LPS—a common component of some types of bacteria—affects the expression of inflammatory genes in leukocytes from horses with gastrointestinal disease. The researchers were also interested in whether the response to LPS differed according to the type of gastrointestinal disease and its outcome.
• The study involved 49 horses with gastrointestinal disease and 10 healthy horses. From these horses, the researchers isolated leukocytes from blood samples and subjected them to three tests: immediate freezing, freezing after incubating in a medium for 4 hours, and freezing after incubating in a medium with LPS for 4 hours.
• The expression of 14 different genes associated with inflammation was analyzed using a Polymerase Chain Reaction (PCR) assay. The researchers compared the results according to the type of disease and its outcome.

Study Results

• The conditions of the horses with gastrointestinal disease varied: 8 had colic of unknown origin, 18 had gastrointestinal inflammation or strangulation, and 23 had non-strangulating gastrointestinal obstruction. Out of the 44 horses that received treatment, 38 were discharged from the hospital, and 6 either died or were euthanized.
• The researchers observed that incubating the leukocytes in medium alone altered the expression of several genes. When the leukocytes were incubated with LPS, there was an increase in the expression of interleukin-10 and monocyte chemotactic protein-3 in both healthy and sick horses.
• Leukocytes from horses with non-strangulating obstruction and horses that survived exhibited less pronounced LPS-induced increases in interleukin-10 expression compared to cells from healthy horses. The opposite was observed for monocyte chemotactic protein-3.

Study Conclusions

• There was no evidence suggesting a diminished response of leukocytes from horses with gastrointestinal disease to ex vivo exposure to LPS. Instead, the pattern of inflammatory gene expression in leukocytes upon incubation with LPS appeared to be linked to the disease’s pathogenesis (origination and development) and prognosis (predicted outcome).