Corneal epithelial layer and limbal niche

The corneal epithelial layer is the stratified, non-keratinized outermost surface of the eye, essential for maintaining transparency and protecting internal structures from environmental damage (PMID: 28837910). It is continuously replenished by a population of limbal stem cells (LSCs) residing within the limbal niche, a specialized anatomical microenvironment located at the transition zone between the cornea and the sclera (PMID: 31513844). This niche provides critical physical and biochemical cues, including extracellular matrix components and signaling pathways like Wnt and Notch, which are necessary to maintain LSC potency and regulate their proliferation (PMID: 26354163). Dysfunction or destruction of the limbal niche leads to limbal stem cell deficiency (LSCD), a condition characterized by corneal vascularization, chronic inflammation, and eventual loss of vision (PMID: 24990481). Therapeutic strategies targeting this system primarily involve regenerative medicine, such as the transplantation of ex vivo expanded stem cells like Holoclar, or the application of growth factors and anti-inflammatory agents to support the endogenous niche. While not a single molecular target, the corneal epithelial layer and limbal niche represent a vital functional unit for ocular surface integrity and a primary focus for advanced cell-based therapies.

Other names

Limbal stem cell nicheCorneal limbusCorneal epitheliumLSC nicheLimbal microenvironment

Restoration of the limbal stem cell population and maintenance of the corneal epithelial microenvironment to promote ocular surface regeneration and restore corneal transparency (PMID: 31513844).