Is there any evidence suggesting niche regulation of limbal epithelial SCs?
It is generally accepted that the differentiation of lineage-committed SCs into mature progenies is a one-way biological process. When rabbit limbocorneal explants were cultivated at an air-fluid interface, epithelial proliferation and stratification is promoted 66. In this model, intrastromal invasion of basal progenitor cells occurs only in the limbal, but not the corneal region 67. Such intrastromal invasion of limbal basal epithelial progenitor cells only occurs when the limbal epithelial tissue is recombined with the live, but not devitalized, limbal stroma, and is abolished when recombined with the live corneal stroma 67. When the corneal epithelial tissue is recombined with the live limbal stroma, there is no intrastromal invasion 67 whereas the basal epithelial cells lose expression of cytokeratin 3 and connexin 43, indicative of de-differentiation of corneal transient amplifying cells (TACs) 66. Conversely, when the limbal epithelial tissue is recombined with the live corneal
