Abstract
Purpose: :
To determine the expression of differentiation and progenitor cell-related markers in the surgically removed corneal tissues that previously underwent autologous cultivated oral mucosal epithelial transplantation (COMET).
Methods: :
Four eyes from 3 chemically and 1 thermally injured patients with total limbal stem cell deficiency received COMET to promote re-epithelialization or corneal reconstruction. Between 10 to 22 months (mean: mean: 14.2 ± 5.5 months) after COMET, the corneal tissues were obtained after penetrating keratoplasty (N=1) and autologous limbal transplantation (N=3). Immunoconfocal microscopy for keratin 3, 4, 12, and 13, MUC5AC, connexin 43, laminin-5, pan-p63, ABCG2, and p75 was performed in those specimens as well as in the oral mucosa and cells at the completion of culture.
Results: :
All the 4 specimens were unanimously positive for keratin 3, 4, and 13 but negative for keratin 12 and MUC5AC, suggesting that the keratinocytes were oral mucosa-derived, and laid over a laminin-5 positive basement membrane. In the basal epithelium, connexin 43 staining was positive in two specimens but negative in another two. Small, compact keratinocytes in the basal epithelium preferentially expressed pan-p63, ABCG2, and p75. Although the staining of pan-p63 and ABCG2 tended to be more than one layer, signal for p75 was consistently localized only to the basal layer.
Conclusions: :
The study demonstrated the long term existence of transplanted oral mucosal epithelial cells (OMECs) in the human corneas. In addition, small, compact cells in the basal epithelium preferentially expressed the keratinocyte stem/progenitor cell markers, which may be indicative of the engraftment of progenitor-like cells of OMECs after COMET.
Keywords: cornea: clinical science • cornea: epithelium • regeneration