Effect of proinflammatory cytokines on cultured spiral ligament fibrocytes.

To clarify the effect of proinflammatory cytokines on spiral ligament (SL) fibrocytes, in vitro studies were performed using secondary cell cultures. Cultures from murine SL fibrocytes were stimulated by interleukin (IL)-1beta or tumor necrosis factor (TNF)-alpha, and secretion of various mediators was measured by enzyme-linked immunosorbent assay. After stimulation with the proinflammatory cytokines, IL-6, TNF-alpha, monocyte chemoattractant protein-1, KC, macrophage inflammatory protein-2, soluble intercellular adhesion molecule-1, and vascular endothelial growth factor levels were elevated. Secretion of these chemokines and other mediators could induce inflammatory cell movement, which would prolong the inflammatory response, leading to fibrocyte damage. Given that SL fibrocytes may play a role in cochlear fluid and ion homeostasis, such fibrocyte disruption could cause cochlear malfunction.