Abstract
Purpose :
To demonstrate the capacity of a pigment epithelial-derived factor (PEDF) peptide 44-mer to facilitate ocular surface epithelialization by enhancing simple limbal epithelial transplantation (SLET) in a rabbit model of total limbal stem cell deficiency (LSCD).
Methods :
Total LSCD was created surgically. Two months later, ocular surface reconstruction was performed by removal of the fibrovascular pannus, followed by SLET and PEDF 44-mer peptide treatment. The SLET-limbal transplants were distributed evenly over an amniotic membrane placed on the cornea and fixed with 44-mer-containing fibrin glue. Topical application of 44-mer-containing ointment for two weeks was started after the surgery. The structure and function of the regenerated ocular surface epithelium were analyzed at three and six months follow-up by slit lamp and impression cytology. Immunohistochemical analysis was performed with antibodies to CK12, CK13, ΔNp63α, CD90 and BrdU. Cells harvested from the regenerated limbal and corneal epithelium were analyzed for colony forming capacity, and expressions of putative stem cell markers by immunostaining assay and quantitative real-time PCR.
Results :
The ocular surface epithelialization occurred in vehicle control eyes with conjunctivalization and vascularization of the cornea and limbus. In PEDF 44-mer treated eyes, an epithelialized and stable corneal surface was seen in all treated eyes by three and six months follow-up. The reconstructed ocular surface showed anatomic and functional recovery of the corneal and limbal epithelia. Immunohistochemical staining demonstrated a broad distribution of cells expressing ΔNp63α throughout the regenerated epithelium. BrdU labeling assay revealed the presence of slow-cycling cells in the basal epithelial layer and the superficial stromal layer of the regenerated limbus.
Conclusions :
The PEDF 44-mer peptide facilitates SLET for the ocular surface reconstruction by expanding stem-like cells from the limbal transplants. This treatment promises to ease and increase the effectiveness of the SLET for the treatment of LSCD.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.