Alpha-1 antitrypsin promotes re-epithelialization by regulating inflammation and migration.

PURPOSE: Regulation of inflammation and re-epithelialization are critical for efficient wound healing. This study explores the role of human α1-antitrypsin (hAAT), an immunomodulatory protein, in modulating inflammation and promoting re-epithelialization across various epithelial cell types.

METHODS

In-vitro, epithelial gap closure and migration assays were performed using two human epithelial cell lines-HaCaT and A549 cells with and without mitomycin C treatment. These cell lines were also used in an in-vitro gel-directed epithelial migration assay. Cells were treated with hAAT, and the gap area was measured using image analysis. Gene expression of inflammatory markers (IL-1β, IL-6, and TNFα) and adhesion molecules (desmoglein-1, plectin, and integrin α6β4) were analyzed using qPCR. In-vivo, corneal abrasions were induced in C57BL/6 mice using an Ophthalmic Burr. Mice received topical hAAT treatment immediately after injury and every 6 hours thereafter. Wound closure was assessed by applying the standard ophthalmic staining technique, fluorescein, and image analysis. Inflammatory markers and adhesion molecule expression were evaluated using qPCR and immunohistochemistry.

RESULTS

In-vitro, hAAT accelerated epithelial gap closure and increased migration distance, independent of cell proliferation. hAAT-treated cells also exhibited earlier peak expressions of IL-1β and IL-6. In-vivo, hAAT treatment accelerated corneal wound closure and resulted in a preference for IL-1Ra over IL-1β expression. hAAT also enhanced the expression of desmoglein-1, plectin, and integrin α6β4, both in-vitro and in-vivo, and increased desmoglein-1 expression in the epithelial migration zone of mouse cornea.

CONCLUSIONS

hAAT enhances re-epithelialization by modulating inflammation, promoting epithelial cell migration, and regulating expression of adhesion molecules.