Amelioration of endotoxin-induced uveitis treated with an I kappa B kinase beta inhibitor in rats

作者：Lennikov Anton; Kitaichi Nobuyoshi^*; Noda Kousuke; Ando Ryo; Dong Zhenyu; Fukuhara Junichi; Kinoshita Satoshi; Namba Kenichi; Mizutani Miho; Fujikawa Tomoyuki; Itai Akiko; Ohno Shigeaki; Ishida Susumu

来源：Molecular Vision, 2012, 18(267-70): 2586-2597.

Purpose: Endotoxin-induced uveitis (EIU) is an animal model for acute ocular inflammation. Several substances play major roles in the development of inflammatory changes in EIU, including tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 beta, and IL-6. These inflammatory cytokines trigger the degradation of I kappa B by activating I kappa B kinases (IKKs). Released nuclear factor kappaB (NF kappa B) subsequently translocates to the nucleus, where NF kappa B expresses its proinflammatory function. IMD-0354, N-(3,5-Bis-trifluoromethylphenyl)-5-chloro-2-hydroxybenzamide, selectively inhibits IKK beta, particularly when induced by proinflammatory cytokines, such as TNF-alpha and IL-1 beta. In the present study, we examined whether IKK beta inhibition has therapeutic effects on EIU by using IMD-0354 and its prodrug IMD-1041. %26lt;br%26gt;Methods: Six-week-old male Lewis rats were used. EIU was induced with subcutaneous injections of 200 mu g of lipopolysaccharide (LPS) from Escherichia coli that had been diluted in 0.1 ml of phosphate-buffered saline. IMD-0354 was administered intraperitoneally at 30, 10, 3, or 0 mg/kg, suspended in 1.0 ml of 0.5% carboxymethyl cellulose sodium. The prodrug IMD-1041 (100 mg/kg) was also administered orally. The rats were euthanized 24 h after LPS injection, and EIU severity was evaluated histologically. The number of infiltrating cells and the protein, TNF-alpha, and monocyte chemoattractant protein-1 (MCP-1) concentrations in the aqueous humor were determined. TNF-alpha and MCP-1 concentrations were quantified with enzyme-linked immunosorbent assay. Eye sections were also stained with anti-NF kappa B and phosphorylated I-kappa B alpha antibodies. %26lt;br%26gt;Results: The number of infiltrating cells in aqueous humor was 53.6 +/- 9.8x10(5), 72.5 +/- 17.0x10(5), 127.25 +/- 32.0x10(5), and 132.0 +/- 25.0x10(5) cells/ml in rats treated with 30, 10, 3, or 0 mg/kg of IMD-0354, respectively. The total protein concentrations of aqueous humor were 92.6 +/- 3.1 mg/ml, 101.5 +/- 6.8 mg/ml, 112.6 +/- 1.9 mg/ml, and 117.33 +/- 1.8 mg/ml in rats treated with 30, 10, 3, and 0 mg/kg of IMD-0354, respectively. Infiltrating cells and protein concentrations were significantly decreased by treatment with IMD-0354 (p %26lt; 0.01). IMD-0354 treatment significantly reduced the concentration of TNF-alpha (p %26lt; 0.05) and MCP-1 (p %26lt; 0.01) in aqueous humor. The number of NF kappa B positive nuclei was reduced when treated with IMD-0354. Furthermore, IMD-0354-treated EIU rats showed only background levels of phosphorylated I-kappa B alpha; however, it was strongly expressed in the iris-ciliary body cell cytoplasm of the IMD-0354 untreated EIU rats. Oral administration of IMD-1041 also decreased the cell number (p %26lt; 0.01) and protein concentration (p %26lt; 0.05) of aqueous humor in EIU. %26lt;br%26gt;Conclusions: Acute uveitis was ameliorated by inhibition of IKK beta in rats. IMD-0354 and its prodrug IMD-1041 seem to be promising candidates for treating intraocular inflammation/uveitis.

• 出版日期2012-10-20