Obesity is associated with low-grade inflammation in adipose tissue, which contributes to the development of obesity-related diseases such as insulin resistance, hypertension and arteriosclerosis. Here we developed an animal model that non-invasively monitors inflammation in adipose tissue using in vivo bioluminescent imaging (BL1) technique In vitro, stimulation with TNF alpha or co-culture with RAW264 macrophages increased bioluminescence in 3T3-L1 adipocytes expressing NF-kappa B-mediated luciferase gene (3T3-L1/NF-kappa B-re-luc2P) In vivo, lipopolysaccharide increased bioluminescence in Mice transplanted with 3T3-L1/NF-kappa B-re-luc2P cells. Moreover, light emission derived from implanted cells was significantly higher in diet-induced obese mice transplanted with 3T3-L1/NF-kappa B-re-luc2P than in lean mice. Our results showed that BL1 technique and 3T3-L1/NF-kappa B-re-luc2P cells provide a useful approach to non-invasively monitor obesity-induced inflammation in adipose tissue in in vivo. (C) 2009 Elsevier Inc. All rights reserved.