Bioluminescence Imaging For Il-1 Beta Expression In Experimental Colitis

Background: Interleukin 1 beta (IL-1 beta) contributes to the development of inflammatory bowel disease (IBD) and is correlated with the severity of intestinal inflammation. However, the precise source of IL-1 beta producing cells in DSS colitis is currently not known.Methods: To determine IL-1 beta activity during intestinal inflammation in real time, an IL-1 beta transgenic mouse has been generated by incorporating the firefly luciferase gene driven by a 4.5-kb fragment of human IL-1 beta gene promoter (named cHS4I-hIL-1 beta P-Luc transgenic mice). Dextran sodium sulfate (DSS) induced colitis was confirmed with clinical presentation and histopathology.Results: A substantial increase in luciferase activity (reflecting IL-1 beta production) in the region of inflamed colon was observed in a time dependent manner, followed by additional activity in the region of the mesenteric lymph node. The up-regulated luciferase activity was suppressed by dexamethasone (steroids) during DSS challenge, consistent with reduced severity of colitis, confirming the specificity of luciferase activity.Conclusions: Our data suggests that bioluminescence is an interesting technology, which may be used to evaluate transcription of various genes in real time in experimental colitis.