E-cadherin and transglutaminase-1 epithelial barrier restoration precedes type IV collagen basement membrane reconstruction following vocal fold mucosal injury.

The vocal fold epithelium is critical to upper airway immunologic defense and water/ion transport; therefore, any form of physical trauma or insult increases the vulnerability of this structure to functional impairment and pathogen invasion/infection. In this study, we examined the reestablishment of epithelial and basement membrane barrier structures in a well-established rat model of vocal fold mucosal injury. We observed active cell recruitment culminating in peak hyperplasia at 3 days postinjury, the establishment of robust E-cadherin+ and transglutaminase-1+ biochemical barrier signals along the epithelial surface by 3 days postinjury, and the persistent absence of a type IV collagen+ basement membrane at 7 days postinjury. The distinct spatial and temporal immunoactivity of these molecules is consistent with a programmed repair process driving the restoration of vocal fold mucosal integrity and permeability. These data may inform future efforts to optimize functional mucosal recovery postinjury and avoid undesirable events such as barrier compromise or epithelial metaplasia.

Alteration in cellular morphology, density and distribution in rat vocal fold mucosa following injury.

The vocal fold mucosa plays an important role in voice production. Its cellular composition and density frequently change under various pathological conditions, often contributing to altered extracellular matrix production, tissue viscoelasticity, and voice quality. In this study, cellular changes in the rat mucosa following a unilateral stripping injury were investigated and analyzed semi-quantitatively. Distinctive and sequential changes in cellular morphology, composition, and density were observed in the mucosa post-injury. Cellular recruitment was a major event during the early stage of injury and reached its peak level by day 5 post-injury. Several types of cells, including neutrophil-like cells, epithelial cells, and fibroblast-like cells, were sequentially recruited. The sequential emergence of reactive cell populations following injury and subsequent reconstruction of the mucosa suggests their involvement in vocal fold tissue repair and scar formation processes.