Objectives: We undertook to describe the genetic and protein composition of subglottic stenosis (SGS) by measuring an array of protein expression and messenger RNA levels within human SGS tissue. We also sought to compare this human array to cytokine expression from a murine model of SGS in order to confirm the effective translational nature of our animal model.
Methods: Human granulation tissue from 10 patients with early symptomatic SGS was compared to control bronchus. The expression levels of 24 different cytokines were measured by a Luminex protein assay and real-time polymerase chain reaction.
Results: The protein expression in human SGS mirrors that seen in murine SGS. Transforming growth factor β1, interleukin 1β, and matrix metalloproteinase 9 were markedly elevated in both human and mouse SGS tissues. The protein array showed a statistically significant elevation in the proinflammatory cytokines tumor necrosis factor α, interleukin 1, granulocyte macrophage colony-stimulating factor, and interferon γ.
Conclusions: This is the first study, to our knowledge, to measure an array of protein expression within human SGS tissue. The expression profile suggests that symptomatic tracheal granulation tissue is mostly within the early inflammatory phase of wound healing and has only begun fibrotic and angiogenic remodeling. This study validates our murine model of SGS, and also helps to define the exact pathways of tissue injury, in the hope of leading to new treatments for this difficult condition.
Keywords: human study; laryngotracheal stenosis; subglottic stenosis; translational study; wound healing.