2-((aminocarbonyl)amino)-5-(4-fluorophenyl)-3-thiophenecarboxamide and Corneal-Ulcer

Corneal ulcer results from excessive collagen degradation in the corneal stroma. Interleukin (IL)-1 promotes this process by activating signaling molecules that include nuclear factor (NF)-kappaB and stimulating the synthesis of matrix metalloproteinases (MMPs) in corneal fibroblasts. NF-kappaB activation is mediated by phosphorylation of the inhibitor IkappaB by IkappaB kinase (IKK)-2 and consequent IkappaB degradation. The authors investigated the effects of the IKK-2 inhibitor [5-(p-fluorophenyl)-2-ureido]thiophene-3-carboxamide (TPCA-1) on collagen degradation by corneal fibroblasts.. Rabbit corneal fibroblasts were cultured in three-dimensional collagen gels. Collagen degradation was evaluated by spectrophotometric quantitation of hydroxyproline in culture supernatants subjected to acid-heat hydrolysis. Expression of MMPs was evaluated by immunoblot analysis, gelatin zymography, and real-time reverse transcription polymerase chain reaction analysis. The phosphorylation and degradation of IkappaBalpha and the subcellular localization of NF-kappaB were examined by immunoblot and immunofluorescence analyses, respectively.. IL-1beta-induced collagen degradation by corneal fibroblasts was inhibited by TPCA-1 in a concentration- and time-dependent manner. TPCA-1 inhibited the IL-1beta-induced expression of MMP-1, -3, and -9 in these cells at both the mRNA and protein levels and the IL-1beta-induced activation of pro-MMP-2. In contrast to dexamethasone, TPCA-1 inhibited the phosphorylation and degradation of IkappaBalpha and the nuclear translocation of NF-kappaB induced by IL-1beta.. An IKK-2 inhibitor blocked IL-1beta-induced collagen degradation by corneal fibroblasts by inhibiting the activation of the NF-kappaB signaling pathway and the upregulation of MMPs. IKK-2 inhibitors are thus potential alternatives to dexamethasone for the treatment of corneal ulcer.

Topics: Amides; Animals; Cells, Cultured; Collagen Type I; Cornea; Corneal Ulcer; Disease Models, Animal; Fibroblasts; Gene Expression; I-kappa B Kinase; Immunoblotting; Immunohistochemistry; Interleukin-1beta; Male; Matrix Metalloproteinase 1; Matrix Metalloproteinase 3; Matrix Metalloproteinase 9; Microscopy, Fluorescence; Rabbits; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spectrophotometry; Thiophenes