Multiple Stem/Progenitor Cells Isolated from the Limbus

Limbal epithelial stem cells (LESCs), which are responsible for the renewal and repair of corneal epithelium, are located in the limbus. The limbus is an important structure for maintaining the normal corneal epithelium. Damage to the limbus can lead to limbal stem cell deficiency (LSCD), a common blind-causing disease. However, the cellular composition of the limbus and the functions of various cell populations have not yet been accurately reproduced, making it difficult to reconstruct the normal structure of the limbus under disease conditions. Currently, there are mature methods for isolating and culturing various types of stem/progenitor cells from the limbus, including LESCs, limbal niche cells (LNCs), and limbal melanocytes (LMs). Successful culture of these cells helps to better investigate their biological functions, their role in sustaining corneal epithelial homeostasis, and their feasibility for basic research or clinical applications. This review summarizes the definitions, functions, and characteristics of these three types of stem/progenitor cells that can be isolated and purified from the limbus, in the hope of drawing attention to and stimulating discussion on this topic. This will help to clarify the cellular composition of the limbus, reconstruct the normal structure of the limbus, and develop innovative stem cell therapy.