N-cadherin Expression in Cultivated Limbal Epithelial Cell Colonies

Abstract

Purpose:: N-cadherin is a key component of the bone marrow stem cell niche. In a recent report, N-cadherin was reported to be expressed in the human limbal epithelial stem cell, and may be a critical cell-to-cell adhesion complex in the limbal epithelial niche. We attempted to determine whether colony formation using NIH3T3 feeder layer is useful as model of the limbal epithelial niche by observing N-cadherin expression.

Methods:: Using human limbal tissue and limbal epithelial colonies with NIH3T3 feeder layer, N-cadherin, Keratin 12 (K12) and Keratin 14 (K14) were examined by immunohistochemistry and immunocytochemistry. Limbal epithelial colonies were separated to two compartments (edge and center) by using laser microdissection, and compared by colony forming efficiency (CFE).

Results:: N-cadherin was sporadically expressed in localized at the basal layer of the limbal epithelium. N-cadherin positive cells were K14 positive and K12 negative cells. N-cadherin expression was located edge of epithelial colonies in direct contact with feeder cells. K12 expression was located at the center of epithelial colonies. CFE was higher at the edge of colonies than the center.

Conclusions:: N-cadherin expression was observed in K12-negative epithelial cells in contact with feeder cells at the periphery of colonies. Colony formation in 3T3 feeders may be used as a model of the limbal epithelial stem cell niche.

Keywords: cornea: epithelium • cell-cell communication • immunohistochemistry