Defining Compartmentalized Stem and Progenitor Populations With Distinct Cell Division Frequency in the Ocular Surface Epithelium

The study investigated the ocular surface epithelium, revealing distinct stem/progenitor cell populations with varying cell division frequencies. Using EdU pulse-chase analysis and lineage tracing in transgenic mice, researchers identified different dynamics of epithelial stem cells in the cornea and conjunctiva. In the limbus, long-lived stem cells labeled with Slc1a3CreER migrated or expanded within the region, while in the central cornea, short-lived progenitor cells were identified. The conjunctival epithelium was regenerated by distinct stem cell populations specific to each region. Severe corneal damage disrupted stem cell compartments, leading to conjunctivalization, whereas milder limbal injury increased laterally-expanding clones. This work provided tools for lineage tracing and defined compartmentalized stem/progenitor populations in ocular homeostasis and injury response.