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A 3-stannylindole was coupled with a 2-bromokojic acid to give an (indolyl)kojic acid that activates the insulin receptor in cell-based assays. This structure represents a hybrid between two Aspergillus natural products, demethylasterriquinone B1 and kojic acid.

A 3-stannylindole was coupled with a 2-bromokojic acid to give an (indolyl)kojic acid that activates the insulin receptor in cell-based assays. This structure represents a hybrid between two Aspergillus natural products, demethylasterriquinone B1 and kojic acid.

A 3-stannylindole was coupled with a 2-bromokojic acid to give an (indolyl)kojic acid that activates the insulin receptor in cell-based assays. This structure represents a hybrid between two Aspergillus natural products, demethylasterriquinone B1 and kojic acid.

Hyperplasia of the middle ear mucosa contributes to the sequelae of acute otitis media. Understanding the signal transduction pathways that mediate hyperplasia could lead to the development of new therapeutic interventions for this disease and its sequelae. Endotoxin derived from bacteria involved in middle ear infection can contribute to the hyperplastic response. The p38 mitogen-activated protein kinase (MAPK) is known to be activated by endotoxin as well as cytokines and other inflammatory mediators that have been documented in otitis media. We assessed the activation of p38 in the middle ear mucosa of an in vivo rat bacterial otitis media model. Strong activity of p38 was observed 1 to 6 h after bacterial inoculation. Activity continued at a lower level for at least 7 days. The effects of p38 activation were assessed using an in vitro model of rat middle ear mucosal hyperplasia in which mucosal growth is stimulated by nontypeable Haemophilus influenzae during acute otitis media. Hyperplastic mucosal explants treated with the p38 alpha and p38 beta inhibitor SB203580 demonstrated significant inhibition of otitis media-stimulated mucosal growth. The results of this study suggest that intracellular signaling via p38 MAPK influences the hyperplastic response of the middle ear mucosa during bacterial otitis media.

Hyperplasia of the middle ear mucosa contributes to the sequelae of acute otitis media. Understanding the signal transduction pathways that mediate hyperplasia could lead to the development of new therapeutic interventions for this disease and its sequelae. Endotoxin derived from bacteria involved in middle ear infection can contribute to the hyperplastic response. The p38 mitogen-activated protein kinase (MAPK) is known to be activated by endotoxin as well as cytokines and other inflammatory mediators that have been documented in otitis media. We assessed the activation of p38 in the middle ear mucosa of an in vivo rat bacterial otitis media model. Strong activity of p38 was observed 1 to 6 h after bacterial inoculation. Activity continued at a lower level for at least 7 days. The effects of p38 activation were assessed using an in vitro model of rat middle ear mucosal hyperplasia in which mucosal growth is stimulated by nontypeable Haemophilus influenzae during acute otitis media. Hyperplastic mucosal explants treated with the p38{alpha} and p38ß inhibitor SB203580 demonstrated significant inhibition of otitis media-stimulated mucosal growth. The results of this study suggest that intracellular signaling via p38 MAPK influences the hyperplastic response of the middle ear mucosa during bacterial otitis media.

Hyperplasia of middle-ear mucosa (MEM) during otitis media (OM) is thought to be partially mediated by the actions of growth factors and their receptors. The intracellular pathway leading from the small G-protein Ras to the extracellular regulated kinases (Erks) often links growth factor stimulation to cellular proliferation. This study assessed whether this pathway is involved in MEM hyperplasia during bacterial OM via the activation of Erk1/Erk2 in MEM of an in vivo rat bacterial OM model. Activation was maximal at 1 and 6 h and at 1 week after introduction of bacteria into the middle ear. Additionally, an in vitro model of rat MEM in bacterial OM was treated with farnesyl transferase inhibitor 277 or the Mek inhibitor U0126. MEM explants treated with either inhibitor demonstrated significant suppression of bacterially induced growth. These data support a role for Ras and Erk signaling in MEM hyperplasia during bacterial OM.