Abstract
Increased interleukin (IL)-8 plays an important role not only in activation and recruitment of neutrophils but also in inducing exaggerated angiogenesis at the inflamed site. In the present study, we investigated the fact that clotrimazole (CLT) inhibits intestinal inflammation, and the inhibitory action is mediated through suppression of IL-8 expression. In the trinitrobenzene sulfonic acid (TNBS)-induced rat colitis model, CLT dose-dependently protected from the TNBS-induced weight loss, colon ulceration, and myeloperoxidase activity increase. In the lesion site, CLT also suppressed the TNBS-induced angiogenesis, IL-8 expression, and nuclear factor (NF)-κB activation. In a cellular model of colitis using tumor necrosis factor (TNF)-α-stimulated HT29 colon epithelial cells, treatment with CLT significantly suppressed TNF-α-mediated IL-8 induction and NF-κB transcriptional activity revealed by a luciferase reporter gene assay. Furthermore, cotreatment with CLT and pyrrolidine dithiocarbamate, a NF-κB inhibitor, synergistically reduced the NF-κB transcriptional activity as well as IL-8 expression. In an in vitro angiogenesis assay, CLT suppressed IL-8-induced proliferation, tube formation, and invasion of human umbilical vein endothelial cells. The in vivo angiogenesis assay using chick chorioallantoic membrane also showed that CLT significantly inhibited the IL-8-induced formation of new blood vessels. Taken together, these results suggest that CLT may prevent the progression of intestinal inflammation by not only down-regulating IL-8 expression but also inhibiting the action of IL-8 in both colon epithelial and vascular endothelial cells during pathogenesis of intestinal inflammation.
Footnotes
-
This work was supported by the Korea Science and Engineering Foundation grant funded by the Korea government (Ministry of Science and Technology) (no. R11-2007-040-02004-0) and by Grant RTI04-01-04 from the Regional Technology Innovation Program of the Ministry of Commerce, Industry, and Energy.
-
D.T. and J.S.L. contributed equally to this work.
-
Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
-
doi:10.1124/jpet.108.141887.
-
ABBREVIATIONS: IBD, inflammatory bowel disease; IL, interleukin; TNF, tumor necrosis factor; CLT, clotrimazole; VEGF, vascular endothelial growth factor; FBS, fetal bovine serum; TNBS, trinitrobenzene sulfonic acid; PDTC, pyrrolidine dithiocarbamate; MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyl tetrazolium bromide; 5-ASA, 5-aminosalicylic acid; MPO, myeloperoxidase; PBS, phosphate-buffered saline; TBS, Tris-buffered saline; STAT, signal transducer and activator of transcription; NF, nuclear factor; COX, cyclooxygenase; H&E, hematoxylin and eosin; vWF, von Willebrand factor; PCR, polymerase chain reaction; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; ELISA, enzyme-linked immunosorbent assay; HUVEC, human umbilical vein endothelial cell; BCECF/AM, 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester; CAM, chick chorioallantoic membrane.
- Received June 16, 2008.
- Accepted August 25, 2008.
- The American Society for Pharmacology and Experimental Therapeutics
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|