Distinct gene expression profiles provoked by polyacrylamide beads (Biogel) during chronic and acute inflammation in mice selected for maximal and minimal inflammatory responses

AIRmax and AIRmin mice differ in their local acute inflammatory reactions to polyacrylamide beads (Biogel). These lines were developed to identify genes that affect the intensity of the acute inflammatory response (AIR) and to investigate the cellular and molecular mechanisms of acute inflammation. Although these lines are well established, differences in their responses to chronic inflammatory Biogel exposure have not yet been described. We investigated whether the selective process that modified the acute inflammatory responses in these animals also affected the development of their chronic inflammatory responses.

Inflammatory exudate cell infiltration was more intense in AIRmax than AIRmin mice at both 48 h and 30 days. Genes involved in signal transduction and immune/inflammatory responses were differentially expressed in the treated skin of AIRmax and AIRmin mice, and divergent expression of some acute inflammatory response genes was detected up to 30 days post-Biogel. However, distinct expression of several pro and anti-inflammatory response genes in both periods was observed.

These results indicate that the selective process for acute inflammation affected the development of chronic inflammatory responses to Biogel, suggesting common genetic control.