Anatomical features and cell-cell interactions in the human limbal epithelial stem cell niche.

Epithelial stem cells of the ocular surface are essential for the maintenance of corneal transparency and therefore for vision. Human corneal/limbal epithelial stem cells (LESCs) are believed to reside in the limbus, the interface between the peripheral cornea and neighboring conjunctiva. A specific anatomical microenvironment called the niche regulates the proliferative and differentiation potential of LESCs and their daughter cells. This review covers multiple structural and functional aspects of the human limbal epithelial stem cell niche, including: anatomical features of the niche, composition of the local extracellular matrix, soluble factors and signaling pathways, interactions with surrounding stromal niche cells and melanocytes.