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Limbal stem cell niche – New insights into structural and molecular composition
Author(s) -
SchlotzerSchrehardt U.
Publication year - 2015
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2015.0244
Subject(s) - microbiology and biotechnology , niche , extracellular matrix , stem cell , mesenchymal stem cell , biology , stem cell niche , progenitor cell , transplantation , regeneration (biology) , limbal stem cell , immunology , cornea , corneal epithelium , neuroscience , medicine , biochemistry , surgery
Summary Maintenance and regeneration of the corneal epithelium relies on unipotent progenitor cells at the corneoscleral limbus, which are regulated by extrinsic factors from their local microenvironment, the stem cell niche. The postulated limbal niche is an anatomically protected site of intimate epithelial‐mesenchymal interaction and is highly vascularised, innervated, pigmented due to intraepithelial melanocytes, infiltrated with immune cells, and supported by a specialized extracellular matrix as well as subepithelial mesenchymal cells emitting soluble signals. For ex vivo expansion and transplantation, limbal stem cells are unfavourably removed from their niche. This lecture outlines our current understanding and novel findings regarding the structural and molecular composition of the limbal niche including specific matrix components, cell‐matrix‐ and cell‐cell adhesion molecules, and niche cell populations, which are involved in stem cell regulation through multiple signalling pathways including the Hedgehog pathway. This lecture also provides an overview of current tissue‐engineering approaches for corneal surface regeneration that aim at incorporating specific niche components, such as matrix proteins, growth and signalling factors, or putative niche cells, into the culture systems in order to support maintenance of stemness and to improve the therapeutic use of limbal stem cell transplantation.