Identification of Two Distinct Stem Cell Clusters, Lrig1-Derived and Wnt/CD44-Dependent, in Corneal Epithelium

The study identified two distinct stem cell populations in the corneal epithelium: Lrig1-derived and Wnt/CD44-dependent. It was discovered that Lrig1+ stem cells remain preserved in the peripheral limbus of aged corneas, despite a downregulation of CD44 expression, which is associated with reduced Wnt activity. Using transgenic mice, the researchers demonstrated that Lrig1+ stem cells are a reservoir for corneal regeneration, while Wnt/CD44-dependent stem cells maintain the cornea under normal conditions. The study concluded that in aging corneas, there is a greater reliance on Lrig1+ stem cells for renewal, and that these cells can continuously renew the cornea independently of CD44.