The effects of thalidomide on the stimulation of NF-kappaB activity and TNF-alpha production by lipopolysaccharide in a human colonic epithelial cell line.
The immunomodulatory and anti-inflammatory effects of thalidomide are associated with inhibition of TNF-alpha levels. However, the mechanism by which thalidomide reduces TNF-alpha production remains elusive. NF-kappaB is known to play a central role in regulating inflammatory responses in patients with inflammatory bowel disease (IBD). We tested whether thalidomide acts through inhibiting NF-kappaB activity. HT-29 cells were stimulated with LPS (1 microg/ml) alone, or after pretreatment with thalidomide (100 microg/ml), and NF-kappaB activity was determined by gel mobility shift assays. RT-PCR was used to measure expression of the proinflammatory cytokine genes TNF-alpha, IL-1beta and IL-8. The level of TNF-alpha mRNA was also analyzed by real-time quantitative RT-PCR, and TNF-alpha protein was measured by ELISA. Thalidomide pretreatment did not affect NF-kappaB activity in HT-29 cells stimulated with LPS but production of TNF-alpha was depressed. Thalidomide was found to accelerate the degradation of TNF-alpha mRNA, but had little effect on IL-1beta or IL-8. These observations suggest that the immunomodulatory effect of thalidomide in colonic epithelial cells is associated with inhibition of TNF-alpha. However, it does not act by inhibiting NF-kappaB but rather by inducing degradation of TNF-alpha mRNA.
Kim
You Sun
YS
Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea.
Kim
Joo Sung
JS
Jung
Hyun Chae
HC
Song
In Sung
IS
D002460:Cell Line; D003106:Colon / Q000033:anatomy & histology*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D015212:Inflammatory Bowel Diseases / Q000276:immunology / Q000378:metabolism; D007375:Interleukin-1 / Q000235:genetics / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013792:Thalidomide / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
D007166:Immunosuppressive Agents; D007375:Interleukin-1; D016209:Interleukin-8; D008070:Lipopolysaccharides; D016328:NF-kappa B; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D013792:Thalidomide