Expression of adhesion molecules by cultured spiral ligament fibrocytes stimulated with proinflammatory cytokines.

Secondary cultures from murine spiral ligament (SL) fibrocytes were stimulated with proinflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor–α (TNF-α), and expression of various adhesion molecules was investigated. Cultures without cytokine stimulation did not show positive immunostaining for vascular cell adhesion molecule–1 (VCAM-1), intercellular adhesion molecule–1 (ICAM-1), or mucosal addressin cell adhesion molecule–1 (MAdCAM-1). Although staining was also negative after stimulation with IL-1β, VCAM-1 and ICAM-1 staining was observed after the cells were stimulated with TNF-α. Reverse transcription-polymerase chain reaction analysis showed messenger RNAs for both VCAM-1 and ICAM-1 expression to be present after fibrocytes were stimulated with TNF-α. These data suggest that activated fibrocytes may cause inflammatory cells to persist in the SL. Given that SL fibrocytes may play a role in homeostasis of cochlear fluid and ion concentrations, prolongation of the inflammatory response ...