The Potential Reversible Transition Between Stem Cells and Transient-Amplifying Cells: The Limbal Epithelial Stem Cell Perspective

The review examines the dynamic relationship between limbal epithelial stem cells (LESCs) and transient-amplifying cells (TACs) in the cornea, focusing on their roles in corneal homeostasis and regeneration. It highlights the potential for TACs to dedifferentiate back into stem cells, especially after injury, suggesting a reversible transition between these cell states. This understanding could impact regenerative medicine by providing insights into tissue repair mechanisms. The review also discusses the 'XYZ hypothesis' of corneal maintenance, the influence of the limbal stem cell niche, and the identification of novel markers for LESCs and TACs. While the presence of progenitor-like cells is established in murine models, their existence in humans needs confirmation. The study suggests that corneal epithelial cells can maintain homeostasis and repair injuries without solely relying on LESCs, opening avenues for therapeutic strategies targeting the LSCN to promote corneal regeneration.