Limbal niche microenvironment (LNM) (LNM)

The limbal niche microenvironment is a specialized anatomical and functional region located at the junction of the cornea and the sclera, known as the limbus. It serves as a protective sanctuary for limbal stem cells (LSCs), which are responsible for the lifelong regeneration of the corneal epithelium and the maintenance of the corneal-conjunctival barrier (Dua et al., 2000). This niche is characterized by a unique composition of extracellular matrix (ECM) proteins, such as laminin and collagen IV, and a diverse population of supporting cells, including mesenchymal stem cells, melanocytes, and vascular endothelial cells, which provide essential biochemical and mechanical cues (Le et al., 2022). Dysfunction or destruction of this microenvironment, often due to chemical burns, Stevens-Johnson syndrome, or genetic factors, leads to Limbal Stem Cell Deficiency (LSCD), resulting in corneal opacity, vascularization, and vision loss (Poli et al., 2020). Therapeutic interventions targeting the limbal niche include the transplantation of ex vivo expanded LSCs (e.g., Holoclar) and the use of growth factors like recombinant human nerve growth factor (Cenegermin) to restore niche signaling and promote epithelial healing. Current research focuses on developing synthetic scaffolds and pharmacological agents, such as ROCK inhibitors, to modulate the niche and enhance the survival and potency of resident or transplanted stem cells.

Other names

Limbal stem cell nicheCorneal epithelial stem cell nicheLimbal microenvironmentCorneal limbal niche

Modulation of the stem cell niche signaling and physical restoration of the limbal stem cell population to promote corneal epithelial renewal and maintain the corneal-conjunctival barrier.